perm filename SUPG03.PAS[S1,ALS] blob sn#487232 filedate 1979-10-04 generic text, type C, neo UTF8
COMMENT ⊗   VALID 00075 PAGES
C REC  PAGE   DESCRIPTION
C00001 00001
C00013 00002	(*PROGRAM HEADER PAGE*)
C00016 00003	(*%IFT D10*)
C00018 00004	(* Compiler-option constants... *)
C00027 00005	(* Constants fixed by S1 architecture... *)
C00034 00006	type
C00068 00007	var
C00081 00008	(** ERROR_CLASS:	ERREXIT ASSERTFAIL ERROR **)
C00102 00009	(** DEBUGGING_CLASS:	PRINTSET PRINTMEMOREG PRINTDATUM PRINT_NESTITEM PRINT_MSTENTRY PRINTNXTINST PRINTNAM PRINTTYP PRINTMTYP PRINTINT **)
C00117 00010	(** SETREP_PROCESSOR_CLASS:	SET_IN SET_DIF SET_INT SET_UNI BUILD_SET *)(*setch*)
C00122 00011	(** S1WORD_PROCESSOR_CLASS:		NEWCODEREC MAKE_NEWINSTREC NEWOPNDXWORDREC NEWOPND2REC GETFIELD GETSIGNEDFIELD PUTFIELD **)
C00132 00012	(** S1WORD_PROCESSOR_CLASS:	REAL_TO_S1WORD ZSYMBOL_TO_S1WORDS INTEGER_TO_S1WORD SETREP_TO_S1WORDS **)
C00143 00013	(** MISCELLANEOUS_CLASS:	LABELHASH LABELNUMBER MIN MAX POWER2 FLDW CVCHR_S1WORD_4 CVOS_S1WORD_12 CVOS_12 CVOS_10 CSP_HASH OPC_HASH NAME_TO_CSP MNEM_TO_OPC **)
C00151 00014	(** INSTRUCTION_PROCESSOR_CLASS:	S1OPNDS_EQUAL S1OPND_TEMPLOC AFTER_FAKEOPS AFTER_NONS1LOC_FAKEOPS INVERT_OPCODE **)
C00158 00015	(** INSTRUCTION_PROCESSOR_CLASS:	DELETE_INSTR INSERT_OPND1 PEEP_LOC_IS_FREE SWAP_OPERANDS INSTR_WORDS PRINTMAINCODE **)
C00167 00016	(** FIXUP_CLASS:			FIXSOP FIXJOP FIXOPND2 ADD_XWPTR_TO_OPNDXWFIXLIST**)
C00172 00017	(** FIXUP_CLASS:			ADD_INSTPTR_TO_OPND2FIXLIST AP_JUMPLIST_PLUS_ONE AP_JUMP_TO_JUMPLIST JMP_TO_TABLE_RECORD_OR_FIX JUMP_TO_LABEL_RECORD_OR_FIX OPND2_RECORD_OR_FIX **)
C00178 00018	(** OPERAND_PROCESSOR_CLASS:		ISREG IS_T_REG IS_T_RG_NOT_RT ISSHORTCONST ISCONST EQUAL_OPERANDS REG_OPERAND IMM_OPERAND REAL_IMM_OPERAND IS_RT IS_RTA IS_RTB USES_RTA USES_RTB **)
C00186 00019	(** OPERAND_PROCESSOR_CLASS:	XTNDED_IMM_OPERAND REGDISP_OPERAND XTNDED_REGDISP_OPERAND EXT_REGADDR_OPERAND ADDR_OPERAND TWIDDLE_OPERAND **)
C00193 00020	(** REGISTER/GLOBAL_MANAGEMENT_CLASS:	ALLOCGBL FREEGBL_S ALLAREFREE ALLOCRG ALLOCRP FREERG_S FINDRGBLOCK FINDRP FINDRG MOVE_AND_FREE_RTB CURRENT_PARMREG_COUNT IS_PARMREG CHECK_DSP_TMP_COLLISION RESERVE_PARMREGS **)
C00206 00021	(** REGISTER/GLOBAL_MANAGEMENT_CLASS:	FREEDATUMREGS FREEREGSBUTONE FREERGSBUTSOME FREEVPAREG FREVPARGUNLESS FREE_TEMP_REGS **)
C00214 00022	(** FORM_CODE CLASS:			FORM_CW_OPERAND FORMFAKEINST FORMSOP FORMJOP FORMTOP FORMXOP
C00221 00023	(** CODE_EMITTER_CLASS:			CONNECT_TO_FIXUP_LIST EMIT_INSTR_OPNDS INSERT_INSTR_OPNDS **)
C00228 00024	(** CODE_EMITTER_CLASS:			EMITFAKEOP INSERTSOP INSERTJOP INSERTXOP EMIT_S1WORD EMIT_ZEROS1WORD **)
C00235 00025	(** CODE_EMITTER_CLASS:			EMITSOP EMITJOP EMITTOP EMITXOP ALLOC_AND_EMIT_TOP **)
C00244 00026	(** DATUM_PROCESSOR_CLASS:	LENGTH_TO_INTOPNDTYPE REG_DATUM COERCE_DATUM CVT_INT_DATUM COERCE_INT_DATUM COERCE_TWO_DATUMS DAT_IS_REG DAT_ISFREE_REG DAT_IS_T_REG DAT_IS_FILADR LOADSTKENTRY LOADSTACKEXCEPT BJUMP_TO_BINTVAL INCREMENT_DATUM XCHANGE_STKENTS **)
C00269 00027	(** DATUM_PROCESSOR_CLASS:	BINTVAL_TO_BJUMP PARMREG_TO_PARMSAVE INC_INDIRECTION TRANSLATE_LVLDSP **)
C00277 00028	(** DATUM_PROCESSOR_CLASS:	IS_SIMPLE FITS_SHRT_OFFSET FITS_SHORT_INDEX IS_CONSTANT IS_CNST_PLUS_OPND PUSHTOP POPTOP PUSH_STKFRAME POP_STKFRAME **)
C00283 00029	(** LITERAL_TABLE_CLASS:	UPD_REALTBL UPD_SETTBL UPD_PROCTBL **)
C00288 00030	(** LITERAL_TABLE_CLASS:	UPD_LBLTBL UPD_BOUNDTBL **)
C00292 00031	(** GET_OPERAND_CLASS:		INSERT_SHORT_VPA VPA_OPERAND_NOSHIFT FIT_IN_OPERAND **)
C00302 00032	(** GET_OPERAND_CLASS:		FIT_ADDRESS_IN_OPERAND **)
C00307 00033	(** GET_OPERAND_CLASS:		GET_OPERAND GET_SHORT_OPERAND GET_ADDRESS **)
C00311 00034	(** GET_OPERAND_CLASS:		MOVE_QUANTITY SLR_QUANTITY COERCE_AND_MOVE_QUANTITY STORE **)
C00318 00035	(** SIMPLIFY_CLASS:		ADD_SUB_SINGLE INC_OR_DEC ADD_TOP_TWO_DATUMS MULT_SINGLE SIMPLIFY ADD_VPAS FPA_LVL_PLUS_VPA1 FPA_DSPLMT_PLUS_VPA1 VPA_FPA_FINALIND SHORT_AND_REG CALCULATE_FPA DEREF_AND_SHIFT SHIFT_VPA1 DEREF DEREF_TO_END **)
C00352 00036	(** DISASSEMBLE_CLASS:			DISASSEMBLE PRINTLOC PRINTIWORD PRINTXW1 PRINTXW2 PRINTOPERAND PRINTREG PRINT_SIGNED_OCTAL PRINTSHORTOP **)
C00370 00037	(** OBJECT_MODULE_SEGMENT_CLASS:	GEN_PSWITCH CODE_CONCRETIZER CONCPAS1 INSERTS1LOC JMPX_TO_JMPA_OPT **)
C00378 00038	(** OBJECT_MODULE_SEGMENT_CLASS:	PEEPHOLE_OPTIMIZER SKIP_JMPA_OPT INC_SKP_OPT **)
C00386 00039	(** OBJECT_MODULE_SEGMENT_CLASS:	COLLAPSE_MOV_OPT **)
C00396 00040	(** OBJECT_MODULE_SEGMENT_CLASS:	PEEPHOLE_OPTIMIZER **)
C00401 00041	(** OBJECT_MODULE_SEGMENT_CLASS:	CONCPAS3 PASS3PCRELFIX INSERT_NOP **)
C00411 00042	(** OBJECT_MODULE_SEGMENT_CLASS:	INIT_SEGMENT GEN_SEGMENT FIXDISP OPEN_SEGMENT CLOSE_SEGMENT CLEAROUT_TXTBUF OPEN_TXT CLOSE_TXT OUT_TXT **)
C00421 00043	(** OBJECT_MODULE_SEGMENT_CLASS:	OPN_SEG CLS_SEG OUT_SEG OPEN_ESD CLS_ESD OUT_ESD OPEN_ESR CLS_ESR OUT_ESR OPEN_RLD CLOSE_RLD OUT_RLD **)
C00430 00044	(** OBJECT_MODULE_SEGMENT_CLASS		**)
C00439 00045	(** OBJECT_MODULE_SEGMENT_CLASS		**)
C00447 00046	(** CALLSTANDARD_CLASS:		SAVE_PARMREGS RESTORE_PARMREGS CALLSTANDARD GENCALL ONE_ARG TWO_SINGLE_ARGS CHECKFILADR ALLOC_EXCESS EXCESS_ARG DEALLOC_EXCESS CHECK_REF_PARM RESULT_PARM **)
C00471 00047	(*** ASSEMBLE_NEXT_INSTRUCTION_CLASS:	ASMNXTINST ***)
C00474 00048	(*** ANI_CLASS:	ARITH_1_OPS UABS UNEG UADD UINC UDEC ***)
C00479 00049	(*** ANI_CLASS:	ARITH_2_OPS USUB ***)
C00487 00050	(*** ANI_CLASS:	ARITH_3_OPS UMPY USQR ***)
C00497 00051	(*** ANI_CLASS:	ARITH_4_OPS UDIV UDMD UMOD ***)
C00503 00052	(*** ANI_CLASS:	COMPARE_SETS REL_OPS UEQU UGEQ UGRT ULEQ ULES UNEQ UIEQU UIGEQ UIGRT UILEQ UILES UINEQ ***)
C00517 00053	(*** ANI_CLASS:	BOOL_OPS UAND UIOR UXOR UNOT UODD ***)
C00523 00054	(*** ANI_CLASS:	SET_OPS UDIF UINT UUNI UINN USGS UADJ UMUS ***)
C00532 00055	(*** ANI_CLASS:	LOAD1_STORE_OPS ULCA ULDA ULDC ULOD ULDP UILOD UPLOD ***)
C00540 00056	(*** ANI_CLASS: LOAD2_STORE_OPS USTR UNSTR UISTR UINST UPSTR UMOV ***)
C00554 00057	(*** ANI_CLASS:	FLOW_CONTROL_OPS UTJP UFJP UUJP UXJP UGOOB ULAB UCLAB ***)
C00564 00058	(*** ANI_CLASS:	ENVIRONMENT_OPS UBGN UEND USTP UENT UBGNB UENDB ***)
C00571 00059	(*** ANI_CLASS:	CHECK_OPS UCHKL UCHKH UCHKT UCHKF UCHKN ***)
C00577 00060	(*** ANI_CLASS:	TYPE_CONV_OPS URND UTYP UTYP2 UCVT UCVT2 ***)
C00582 00061	(*** ANI_CLASS:	VIRT_STK_OPS UDUP USWP UIXA ***)
C00591 00062	(*** ANI_CLASS:	PROC_CALL_OPS UMST UPAR UCUP UICUP UCSP URET ***)
C00612 00063	(*** ANI_CLASS:	IMP_EXP_OPS UIMPP UIMPV UEXPP UEXPV ***)
C00613 00064	(*** ANI_CLASS:	COMP_TIME_OPS UCOMM UOPTN ULEX USYM ULIVE UDEAD UDOA UDEF UMDEF ULOC ***)
C00621 00065	(*** ANI_CLASS:		***)
C00625 00066	(** READNXTINST_CLASS:	READNXTINST READNAM READTYP READMTYP READINT READREAL READSTRING READSET UUNK *)
C00638 00067	(** INITIALIZE_CLASS:	INITIALIZE ENTER_OPC ENTER_CSP INIT1 **)
C00662 00068	(** INITIALIZE_CLASS:			INIT2 **)
C00680 00069	(** INITIALIZE_CLASS:			INIT3 **)
C00705 00070	(** INITIALIZE_CLASS:			INIT4 **)
C00730 00071	(** INITIALIZE_CLASS:			INIT5 **)
C00754 00072	(** INITIALIZE_CLASS:			INIT6 **)
C00762 00073	(** INITIALIZE_CLASS:			INIT7 **)
C00774 00074	(** INITIALIZE_CLASS:			 **)
C00775 00075	(** MAIN_PROGRAM:			**)
C00783 ENDMK
C⊗;
(*PROGRAM HEADER PAGE*)

(*%SETF D10*)		(*DEC-10 VERSION?*)
(*%SETT SET4*)		(*4-WORD SETS ALLOWED BY HOST COMPILER?*)
(*%SETT ASCII*)		(*ASCII USED FOR CHARACTERS?*)

(*%IFT D10*)
(*$Y-,O-,D+,R64,S2000*)       (*PAS10 OPTIONS*) 	(*2AUG79 PTZ*)
(*%ELSE*)
%(*$X+,B+,D+,M120*)		(*PCPASC OPTIONS*)  	(*4AUG79 PTZ*)\
(*%ENDC*)

(*	EXPLANATION OF PAS10 OPTIONS			     DEFAULT

D+	DEBUG AND POSTMORTEM DUMP				-
E+	EXTERNAL CALLS TO LEVEL 1 PROCEDURES ALLOWED		-
Fn	FILE OPTION						1
I+	FORTRAN I/O IN EXTERNAL FORTRAN SUBROUTINES		-
L+	OBJECT LISTING						-
Rn	SIZE OF LOW-SEGMENT				(SEE PAS10 MANUAL)
Sn	MAX INSTRUCTIONS PER STATEMENT			       1000
T+	RUNTIME CHECK						+
U+	72 COLUMN FORMAT					-
Xn	HIGHEST REGISTER FOR PARAMETERS				6
*)


(*	EXPLANATION OF PCPASC OPTIONS			     DEFAULT

A+	GENERATE S1 ASSEMBLY MODULE				-
A-	GENERATE S1 OBJECT MODULE
B+	BOUNDS CHECKING, BUT ALLOW 'BIG' CHARACTERS		-
C+	EMIT PCODE						+
D+	RUNTIME CHECKING OF POINTER, INDEX, SUBRANGE VALUES	-
E+	FILE IS IN EBCDIC CHARACTER SET				-
F+	SAVE FPR'S ON PROCEDURE/FUNCTION ENTRY			+
K+	ENABLE STATEMENT EXECUTION COUNTING			-
L+	LIST SOURCE PROGRAM					+
M+	72 COLUMN FORMAT					+
P+	DOUBLE-WORD BOUNDARY ALIGNMENT				-
S+	SAVE GPR'S ON PROCEDURE/FUNCTION ENTRY			+
T+	PRINT SYMBOL TABLES (FOR POST-PROCESSOR)		-
U+	GET STATISTICS?? 2ND PARAMETER TO PCODE BGN INSTR.	-
V+	?? 3RD PCODE BGN INSTRUCTION PARAMETER			-
X+	USE ACTUAL PROCEDURE NAMES FOR EXTERNAL REFERENCES	-
X-	GENERATE UNIQUE 8-CHAR NAMES FOR EXTERNAL REFERENCES
*)

(*%IFT D10*)
program SOPAIPILLA (INPUT*,OUTPUT,PRR);
(*%ELSE*)
%program SOPAIPILLA (INPUT,OUTPUT,PRR);\
(*%ENDC*)


(*SOPAIPILLA - Stanford Optimizing Packed-Address Implementation of a
universal Pcode Intermediate Language Logical Assembler*)

(*CAVEAT : This is a preliminary version of this program.  It should not
be considered in any sense in final form, since it is undergoing daily
development and modification.*)

(*This program translates P-Code, an intermediate language invented as a
target language of a PASCAL compiler, into S-1 machine language.  During
the translation process, a number of local optimizations are performed.  A
detailed description of the logic of the program, including discussion of
the optimizations performed is contained in the document SOPADOPE*)

(*SOPAIPILLA was written during summer 1977 by Erik J. Gilbert and David
W. Wall of the Computer Science Department at Stanford University.  Much
of its internal philosophy is based on a similar compiler for the IBM 370
written by Sassan Hazeghi, also of the Stanford C.S. Dept.*)

(* This version, SUPG01, is descended from:

	SOPU[S1,ALS]	23AUG79
	SOPZ21[SOP,S1]	18AUG79
*)
(* Compiler-option constants... *)

const

SOPA_ID = 'SUPG03, version of 27SEP79 13:33 (PN)';

(*%IFT ASCII*)
CHARDIF = 0;				
(*%ELSE*)
%CHARDIF = 40B;\
(*%ENDC*)

(* LCW 2AUG78
This compiler will not compile programs containing constants outside the
range of MIN_ON_COMP_MACH..MAX_ON_COMP_MACH.  Furthermore,
MAX_ON_COMP_MACH and MIN_ON_COMP_MACH must be set to the minimum and
maximum values, respectively, of integers of the machine on which this
compiler runs.  BITS_ON_COMP_MACH must be set to the number of bits in
an integer of the machine on which the compiler runs.  However, when
running the compiler on a machine with a word size larger than that of
the S1, these constants must be set as if that machine had a word size
equal to that of the S1. Never try to run this program on a machine with
word length less than 32.
*)

(*MAX_ON_COMP_MACH = 2147483647;		" 2**31 - 1 (370) "	*)
(*MIN_ON_COMP_MACH = -2147483648;		" -2**31 (370) "	*)
(*BITS_ON_COMP_MACH = 32;			" 370 "			*)
(*MAX_EXP_ON_COMP_MACH = 30;			" two less than bits "	*)

MAX_ON_COMP_MACH = 34359738367;         	" 2**35 - 1 (10/S1) "
MIN_ON_COMP_MACH = -34359738367;	      	" -2**35 (10/S1) "
(* MIN_ON_COMP_MACH should be one less, but runtime won't accept it ... *)
BITS_ON_COMP_MACH = 36;                 	" 10/S1 "
MAX_EXP_ON_COMP_MACH = 34;			" two less than bits "

BLKMOV_THRESH = 225;    	(*PMOVs of >= 225 QWs generate BLKMOV*)
				(*Everything < 225 QWs can be done with
				at most 3 MOVMQs or 2 MOVMSs*)

MINPARS1REG = 8;        	(*smallest numbered parameter register*)
MAXDSPS1REG = 29;       	(*largest numbered display register*)

MAXPAREG = 10;   		(*Maximum number of parameter registers*)
MAXPAREGM1 = 9;  		(*Maximum logical index of a parameter reg*)
MINBLOCK = 1;			(*Minimun legal number for a memory block*)
MAXBLOCK = 500;			(*Maximum legal number for a memory block*)
ILLBLOCKNO = -1;		(*Illegal block number for initialization*)
MAXLVL = 8;      		(*Maximum nesting of procedure declarations*)
MAXLBL = 99999;			(*Maximum label integer*)
MAXCODEW = 999999; 		(*Maximum number of words in a CODEREC*)
ALFASIZE = 16;			(*Maximum length of type ALFA*)
COMMLEN = 64;			(*Maximum printed length of the comment field
				   in a COMM instruction. *)(*peg 24aug79*)
STRINGMAX = 150; 		(*Maximum length of a string, in characters*)
SEG_START_RELPC = 0;  		(*Relative PC of segment start*)
SEG_EP_DISP = 16;  		(*Storage units from seg start to entry point*)
TMPDATAWORDSGUESS = 3;
SFLDMAX = 3;     		(*VPA shift maximum*)
NILVAL = -1;

MAXS1LOC = 16777215;	(*2**24-1 - really should be = MAXS1ADDR, 2**30-1*)
S1LOCUNDEF = MAXS1LOC;
MAXPEEP_PASSES = 2;	(*Maximum number of passes in PEEPHOLE_OPTIMIZER*)   (*PTZ*)

MINSTKINX = -1;
MAXSTKINX = 30;		(* peg 09jul79 -- may have to be increased.*)
TMPD1 = MINSTKINX;	(*TMPD1 is used to hold synthetic DATUMs*)
MINFRAME = 1;		(* peg 09jul79 *)
MAXFRAME = 15;		(* peg 09jul79 *)	(*Same as MAXMST*)

MAXMST = 15;            	(*Maximum nesting of function calls*)

MAXESDINDEX = 1000;
MAXESRINDEX = 1000;
MAXZINDEX = 1000;       	(*max of two above*)

LBLHTSIZE = 197;  		(*prime*)
LBLHTSIZEM1 = 196;
CSPHTSIZE = 91;   		(*prime*)
CSPHTSIZEM1 = 90;
OPCHTSIZE = 263;		(* ALS 7/16/79*)
OPCHTSIZEM1 = 262;
(*OPCHTSIZE = 197;*)		(*prime*)
(*OPCHTSIZEM1 = 196;*)

(*370 values for 4 constants ... *)
(*
LCAFTMST = 80;
FNCRSLT = 72;
LASTFILBUF = 280;
L1LOCALDATATRANSLATION = 408;	"*LASTFILBUF - MINSHORTOFFSET*WORDUNITS*"
*)

(*S1 valuesfor 4 constants ... *)
LCAFTMST = 8;
FNCRSLT = 0;
LASTFILBUF = 44;		(*level 1 dsplmt of first local variable, 
				which is after level 1 MST part.*)
(* L1LOCALDATATRANSLATION = 172; *) (*LASTFILBUF - MINSHORTOFFSET*WORDUNITS*)
(* ↑ commented out: peg 27jul79 *)

LCIOFILADR = 8;			(*level 1 dspl of the global variable used
				to store current I/O file addr*)

(* Address tranlation constants -- als/peg 18jul79...*)
FIRSTADDR = 0;		(*Address (in qwords) of first local variable for
			   > L1 procedures = FNCRSLT*)
L1FIRSTADDR = 44;	(*Address (in qwords) of first local variable for
			   L1 procedures = LASTFILBUF*)
OFFSET_IN_VARS = 128;	(*Offset of display in local variable area =
			   -MINSHORTOFFSET*WORDUNITS *)
R_OFFSET = -172;	(*Offset of RegParmSaveArea from display =
			   -REGIMAGEAREASIZE - OFFSET_IN_VARS*)
M_OFFSET = -128;	(*Offset of beginning of M memory area from
			   display = -OFFSET_IN_VARS*)
DISPLAY_OFFSET = 172;	(*Offset of display from beginning of segment, not
			    including the EvalSaveArea, for > L1 procedures*)
L1DISPLAY_OFFSET = 172;	(*Offset of display from beginning of segment, not
			    including the EvalSaveArea, for L1 procedure*)
FILE_OFFSET = -172;	(*Offset of file buffers from display =
			   -FILBUFAREASIZE - OFFSET_IN_VARS*)
REGIMAGEAREASIZE = 44;	(*Size of Register Image Area, in quarterwords =
			    (MAXPAREG + 1)*WORDUNITS*)
FILBUFAREASIZE = 44;	(*Size of File Buffer Area, in quarterwords =
			     LASTFILBUF*)
(*...Address tranlation constants -- als/peg 18jul79 *)

(* ...end compiler-option constants *)
(* Constants fixed by S1 architecture... *)

FIRSTS1REG = 0;
S1RCPL = 0;		(*register to start CPL block-descriptor*)
S1R0 = 0;
S1RPC = 3;
S1RTA = 4;
S1RTB = 6;
S1RSP = 30;		(*stack-pointer register*)
S1RNP = 31;		(*heap-pointer register*)
LASTS1REG = 31;
S1RNPMEMADR = 124;      (*memory address of S1RNP*)	       (*BNDTRPKLU*)

FIRSTS1GBL = 32;	(*globals are low-core memory words*)
S1GMEMEND = 32;		(*runtime sets up address of last QW of heap here*)
S1GSEGBASE = 33;  	(*global number of segment base for trace*)
S1GBLZ = 34;		(*global number of zero word for block descriptor use*)
S1GCPLPL = 35;		(*global number of CPLPL block-descriptor*)
LASTS1GBL = 39;		(*number of last S1 low-core global*)
		(*DO NOT assign globals beyond 47 (octal addr 276) without
		  also changing FSIM, PASRUN, and S1 DDT.  - EJG 26JAN79 *)

MAXS1ADDR = 1073741823; 	(*2**30 - 1*)		(*EJG*)
MINS1DISP = -16777216;  	(*-2**24*)
MAXS1DISP = 16777215;   	(*2**24 - 1*)
MINSIGNEDS1ADDR = -536870912;   (*-2**29*)
MAXSIGNEDS1ADDR = 536870911;    (*2**29-1*)
MINSHORTOFFSET = -32;
MAXSHORTOFFSET = 31;
MINSHORTCONSTANT = -32;
MAXSHORTCONSTANT = 31;
MAXINDEXSHIFT = 3;
MINJPROFFSET = -2048;
MAXJPROFFSET = 2047;
MINSKPOFFSET = -8;
MAXSKPOFFSET = 7;
MAXMOVMQ = 32;          	(*64 and 128 are handled specially*)
				(*MAXMOVMQ must be a multiple of WORDUNITS*)
MAXMOVMS = 32;			(*5DEC78 ALS*)
S1TRUEFLAG = -1;

DALIGNSHIFT = 3;
DALIGNMUL = 8;

CHARBITS = 9;
QWBITS = 9;
HWBITS = 18;
WORDBITS =  36;
DWBITS = 72;			(* peg 09jul79 *)
WORDCHARS = 4;
QUARTERWORDUNITS = 1;
HALFWORDUNITS = 2;
WORDUNITS = 4;
DOUBLEWORDUNITS = 8;
PAGEUNITS = 2048;
MAXALIGNBOUNDARY = 4;

SET_SIZE = 144;			(*Number of set elements on the S1.*)
SET_MAX = 143;			(*Max legal value of a set element on the S1.*)
S1SETREP_SIZE = 4;		(*Number of S1 words used/set.*)
S1SETREP_MAX = 3;		(*Number of S1 words used/set - 1.*)
NUMOFSETPARTS = 2;		(*Number of double-word parts/set.*)
SETPART_MAX = 1;		(*Number of double-word parts/set - 1.*)

(*%IFF SET4*)
HOST_SET_SIZE = 64;		(*Number of set elements/set in host compiler.*)
HOST_SET_MAX = 63;		(*Max legal value of a host set element.*)
SETREP_MAX = 2;			(*Number of host sets used/set - 1.*)
(*%ELSE*)
%HOST_SET_SIZE = 144;		(*Number of set elements/set in host compiler.*)\
%HOST_SET_MAX = 143;		(*Max legal value of a host set element.*)\
(*%ENDC*)

OPCODE_START = 0;       OPCODE_LEN = 12;
OPND1_START = 12;       OPND1_LEN = 12;
OPND2_START = 24;       OPND2_LEN = 12;
T_START = 10;           T_LEN = 2;
PR_START = 11;          PR_LEN = 1;
SKP_START = 8;          SKP_LEN = 4;
J_START = 24;           J_LEN = 12;
FAKEOPND_START = 12;    FAKEOPND_LEN = 24;
OPND_START = 0;		OPND_LEN = 12;					(*PTZ*)
OPNDX_START = 0;        OPNDX_LEN = 1;
OPNDREG_START = 1;      OPNDREG_LEN = 5;
OPNDF_START = 6;        OPNDF_LEN = 6;
OPND1X_START = 12;      OPND1X_LEN = 1;
OPND1REG_START = 13;    OPND1REG_LEN = 5;
OPND1F_START = 18;      OPND1F_LEN = 6;
OPND2X_START = 24;      OPND2X_LEN = 1;
OPND2REG_START = 25;    OPND2REG_LEN = 5;
OPND2F_START = 30;      OPND2F_LEN = 6;
XWP_START = 0;          XWP_LEN = 1;
XWV_START = 1;          XWV_LEN = 1;
XWD_START = 2;          XWD_LEN = 1;
XWI_START = 3;          XWI_LEN = 1;
XWS_START = 4;          XWS_LEN = 2;
XWADDR_START = 6;       XWADDR_LEN = 30;
XWREG_START = 6;        XWREG_LEN = 5;
XWDISP_START = 11;      XWDISP_LEN = 25;
BNDTYP_START = 0;       BNDTYP_LEN = 9;

RGS = 0;  MEM = 1;  		(*should be enum. type, but alignment*)

(* ...end constants fixed by S1 architecture *)
type

ERRORCODE = (
    WARITH_ON_WRONG_DT,
    WNOT_IMPLEMENTED,
    WILLEGAL_LABEL,
    WABS_OR_NEG_OF_NONSIGNED,
    WADDR_OUT_OF_RANGE,
    WADDRESS_CHECK_ON_NONADDRESS,
    WALIGNMENT_ERROR,
    WANDOR_NEEDS_BOOLEAN,
    WBGN_STP_NAME_MISMATCH,
    WENT_AND_PLOD_INCONSISTENT,
    WENT_END_NAME_MISMATCH,
    WENT_SPECIFIED_WRONG_PARMS,
    WBINARY_OPND_TYPE_CONFLICT,
    WBOOL_IS_TRUE,
    WBOOL_NOT_TRUE,
    WCHECKED_CONSTANT_OUT_OF_RANGE,
    WCHKF_CHKT_NEEDS_BOOLEAN,
    WCHKN_NULL_TOP,
    WCHKN_NOT_ADDRESS,
    WCHECKING_INVALID_TYPE,
    WCHR_NEEDS_INT,
    WCOERCION_INVALID,
    WCOMPARE_ILLEGAL,
    WCOMPM_NEEDS_ADDR,
    WCONST_OUT_OF_RANGE_FOR_SET,
    WDISP_OUT_OF_RANGE,
    WDUP_ON_EMPTY_STACK,
    WEQU_etc_with_TYP_is_TYPM,
    WEXPR_TOO_COMPLEX,
    WFILE_ADDRESS_NEEDED,
    WTJP_FJP_NEEDS_BOOLEAN,
    WTJP_FJP_WITH_NONEMPTY_STACK,
    WFIX_OF_INVALID_TYPE,
    WFLOAT_OF_INVALID_TYPE,
    WFUNC_CALLS_NESTED_TOO_DEEPLY,
    WIEQU_etc_with_TYP_not_TYPM,
    WILLEGAL_PROC_TYPECODE,
    WINCOMPATIBLE_TYPES,
    WINDEX_WITHOUT_BASE,
    WINDEXING_IN_PARMS,
    WINN_REQUIRES_SET_ON_TOP_OF_STACK,
    WINSTR_TYPE_NOT_DATUM_TYPE,
    WINSUFF_PARMS_SPECIFIED,
    W2_MANY_PARMS_SPECIFIED,
    WINTEGER_CONSTANT_DIV_MOD_BY_ZERO,
    WINVAL_BLOCK_NUMBER,
    WINVAL_CSP,
    WINVAL_OPC,
    WINVAL_TRACE,
    WINVAL_TYP_ON_LDC,
    WINVAL_U_TYPECODE,
    WINVALID_DISPLACEMENT,
    WINVALID_TYPE_COERCION,
    WINVALID_LEVEL,
    WINVALID_MEMORY_TYPE,
    WIXA_NEEDS_ADDR,
    WL_LPTR_LBLNUM_UNDEFINED,
    WLAST_SST_PARM_TOO_BIG,
    WLOADING_STRING,
    WISTR_INST_NEEDS_ADDRS,
    WMOV_NEEDS_ADDRS,
    WMST_SPECIFIED_INSUFF_PARM_STORAGE,
    WMST_WITHOUT_CUP_IN_LAST_SEGMENT,
    WMULT_DEFINED_LAB,
    WNESTING_TOO_DEEP_OR_EXPRESSION_TOO_COMPLEX,
    WNEW_MUST_HAVE_ADDR_AND_INT,
    WNOT_AN_ADDR,
    WNOT_DISCRETE_TYPE,
    WNOT_NEEDS_BOOLEAN,
    WNULLREF,
    WODD_REQUIRES_AN_INTEGER,
    WORD_NEEDS_INT_BOOLEAN_OR_CHAR,
    WPOP_OF_EMPTY_STACK,
    WREAL_CONSTANT_DIVISION_BY_ZERO,
    WREGPARMS_SPEC_TOO_LOW_IN_MST,
    WROUND_OF_NON_REAL,				(*ROUND*)
    WRST_NEEDS_ADDR,
    WSAV_NEEDS_ADDR,
    WSET_OPERATION_ON_NONSET_TYPES,
    WSGS_OR_INN_REQUIRES_INT_CHAR_OR_BOOLEAN,
    WSIO_DIDNT_SEE_FILEADDR,
    WSIO_WITH_NONADDRESS,
    WSQUARE_OF_INVALID_TYPE,
    WSTACK_LEFT_NONEMPTY_IN_LAST_SEGMENT,
    WSTACK_NON_EMPTY,
    WSTACK_NOT_SINGLE,
    WSWP_NOT_2,
    WSWP_TYP_ERROR,
    W2_MANY_BGNBS,
    W2_MANY_ENDBS,
    WTOO_LARGE_K_OR_L,
    WTRUNCATE_OF_INVALID_TYPE,
    WCVT_WITH_INVALID,
    WTYP_WITH_INVALID,
    WUJP_WITH_NONEMPTY_STACK,
    WWRONG_INSTR_DATATYPE,
    WWRONG_COMPARE,
    WWRONG_RESULT_NUMBER,
    WXJP_WITHOUT_SINGLETON_STACK);



(* Corrected list June 7, 1979*)
U_OPCODE = (
    UABS ,UADD ,USUB ,UMPY ,UDIV ,UADJ ,UAND ,UBGN ,UBGNB,UCHKF,
    UCHKH,UCHKL,UCHKN,UCHKT,UCLAB,UCOMM,UCSP ,UCUP ,UCVT ,UCVT2,
    UDEAD,UDEC ,UDEF ,UDIF ,UDMD ,UDOA ,UDSP ,UDUP ,UEND ,UENDB,
    UENT ,UEXPP,UEXPV,UFJP ,UICUP,
    UGOOB,UMOV ,				(*UMOV added 30Jun79 by peg*)
    UEQU ,UNEQ ,UGEQ ,UGRT ,ULEQ ,
    ULES ,UIEQU,UINEQ,UIGEQ,UIGRT,UILEQ,UILES,UILOD,UIMPP,
    UIMPV,UINC ,UINN ,UINST,UINT ,UIOR ,UISTR,UIXA ,ULAB ,ULCA ,
    ULDA ,ULDC ,ULDP ,ULEX ,ULIVE,ULOC ,ULOD ,UMDEF,UMOD ,UMST ,
    UMUS ,UNEG ,UNEW ,UNOT ,UNSTR,UODD ,UOPTN,UPAR ,UPLEX,UPLOD,
    UPSTR,URET ,URND ,USDEF,USGS ,USQR ,USTP ,USTR ,USWP ,USYM ,
    UTJP ,UTYP ,UTYP2,UUJP ,UUNI ,UUNK ,UXJP ,UXOR );

P_STANDARDPROC = (
    QATN, QCLK, QCOS, QEIO, QELN, QEOF, QEXP, QGET, QLOG, QNEW,
    QPUT, QRDB, QRDC, QRDI, QRDR, QRDS, QRES, QREW, QRLN, QRND,	(*ROUND*)
    QRST, QSAV, QSIN, QSIO, QSQT, QTRP, QWLN, QWRB, QWRC, QWRI,
    QWRR, QWRS, QXIT);

S1OPCODE = (
    XILLEGAL,
    XPLOC,
    XS1LOC,
    XFREEREG,								(*PBK*)

    XABS_Q,
    XABS_H,
    XABS_S,
    XABS_D,
    XADD_S,
    XADD_D,
    XADJSP_UP,
    XADJSP_DN,
    XALLOC_1,
    XAND_Q,
    XAND_D,
    XAND_TC_D,
    XAND_CT_D,
    XBLCMP_EQL_Q,
    XBLCMP_NEQ_Q,
    XBLCMP_GEQ_Q,
    XBLCMP_GTR_Q,
    XBLCMP_LEQ_Q,
    XBLCMP_LSS_Q,
    XBLKMOV,
    XBTRP_B_Q,
    XBTRP_B_H,
    XBTRP_B_S,
    XBTRP_B_D,
    XBTRP_M1_Q,
    XBTRP_M1_H,
    XBTRP_M1_S,
    XBTRP_M1_D,
    XBTRP_0_Q,
    XBTRP_0_H,
    XBTRP_0_S,
    XBTRP_0_D,
    XBTRP_1_Q,
    XBTRP_1_H,
    XBTRP_1_S,
    XBTRP_1_D,
    XDEC_S,
    XDJMPA,							(*25JUN79 PTZ...*)
    XDSKP_EQL,		(*start of S1SKIPOPCODE*)
    XDSKP_NEQ,
    XDSKP_GEQ,
    XDSKP_GTR,
    XDSKP_LEQ,
    XDSKP_LSS,							(*...25JUN79 PTZ*)
    XFX_DM_S_S,
    XFX_DM_S_D,
    XFX_FL_S_S,
    XFLOAT_S_Q,
    XFLOAT_S_H,
    XFLOAT_S_S,
    XFLOAT_S_D,
    XFADD_S,
    XFADD_D,
    XFSUB_S,
    XFSUBV_S,
    XFSUB_D,
    XFSUBV_D,
    XFMULT_S,
    XFMULT_D,
    XFDIV_S,
    XFDIVV_S,
    XFDIV_D,
    XFDIVV_D,
    XFTRANS_S_D,
    XFTRANS_D_S,
    XHALT,						       (*BNDTRPKLU*)
    XIJMPA,							(*25JUN79 PTZ*)
    XINC_S,
    XISKP_EQL,     						(*25JUN79 PTZ...*)
    XISKP_NEQ,
    XISKP_GEQ,
    XISKP_GTR,
    XISKP_LEQ,
    XISKP_LSS,							(*...25JUN79 PTZ*)
    XJMPA,
    XJMPZ_EQL_Q,
    XJMPZ_NEQ_Q,		(* als/peg 19jul79 *)
    XJSR,
    XMOV_A,
    XMOV_Q_Q,
    XMOV_Q_H,
    XMOV_H_Q,
    XMOV_H_H,
    XMOV_Q_S,
    XMOV_H_S,
    XMOV_S_Q,
    XMOV_S_H,
    XMOV_S_S,
    XMOV_Q_D,
    XMOV_H_D,
    XMOV_S_D,
    XMOV_D_Q,
    XMOV_D_H,
    XMOV_D_S,
    XMOV_D_D,
    XMOVMQ_2,		
    XMOVMQ_3,
    XMOVMQ_4,
    XMOVMQ_5,
    XMOVMQ_6,
    XMOVMQ_7,
    XMOVMQ_8,
    XMOVMQ_9,
    XMOVMQ_10,
    XMOVMQ_11,
    XMOVMQ_12,
    XMOVMQ_13,
    XMOVMQ_14,
    XMOVMQ_15,
    XMOVMQ_16,
    XMOVMQ_17,
    XMOVMQ_18,
    XMOVMQ_19,
    XMOVMQ_20,
    XMOVMQ_21,
    XMOVMQ_22,
    XMOVMQ_23,
    XMOVMQ_24,
    XMOVMQ_25,
    XMOVMQ_26,
    XMOVMQ_27,
    XMOVMQ_28,
    XMOVMQ_29,
    XMOVMQ_30,
    XMOVMQ_31,
    XMOVMQ_32,
    XMOVMQ_64,
    XMOVMQ_128,
    XMOVMS_2,			(*through MOVMS_32 added 5/dec/78 ALS*)
    XMOVMS_3,
    XMOVMS_4,
    XMOVMS_5,
    XMOVMS_6,
    XMOVMS_7,
    XMOVMS_8,
    XMOVMS_9,
    XMOVMS_10,
    XMOVMS_11,
    XMOVMS_12,
    XMOVMS_13,
    XMOVMS_14,
    XMOVMS_15,
    XMOVMS_16,
    XMOVMS_17,
    XMOVMS_18,
    XMOVMS_19,
    XMOVMS_20,
    XMOVMS_21,
    XMOVMS_22,
    XMOVMS_23,
    XMOVMS_24,
    XMOVMS_25,
    XMOVMS_26,
    XMOVMS_27,
    XMOVMS_28,
    XMOVMS_29,
    XMOVMS_30,
    XMOVMS_31,
    XMOVMS_32,
    XMULT_S,
    XMULT_D,
    XDIV_S,		(* added 18jul79 als/peg *)
    XNEG_Q,
    XNEG_H,
    XNEG_S,
    XNEG_D,
    XNOP,
    XOR_Q,
    XOR_D,
    XQUO_S,
    XQUOV_S,
    XQUO_D,
    XQUOV_D,
    XREM_S,
    XREMV_S,
    XREM_D,
    XREMV_D,
    XRETSR,
    XSHF_LF_D,
    XSHFV_LF_D,
    XSHFA_LF_S,
    XSHFAV_LF_S,
    XSKP_EQL_Q,     (*Start of S1SKIPOPCODE subrange*)
    XSKP_NEQ_Q,
    XSKP_GEQ_Q,
    XSKP_GTR_Q,
    XSKP_LEQ_Q,
    XSKP_LSS_Q,
    XSKP_EQL_H,
    XSKP_NEQ_H,
    XSKP_GEQ_H,
    XSKP_GTR_H,
    XSKP_LEQ_H,
    XSKP_LSS_H,
    XSKP_EQL_S,
    XSKP_NEQ_S,
    XSKP_GEQ_S,
    XSKP_GTR_S,
    XSKP_LEQ_S,
    XSKP_LSS_S,
    XSKP_EQL_D,
    XSKP_NEQ_D,
    XSKP_GEQ_D,
    XSKP_GTR_D,
    XSKP_LEQ_D,
    XSKP_LSS_D,
    XSKP_NON_Q,
    XSKP_NON_H,
    XSKP_NON_S,
    XSKP_NON_D,
    XSKP_ANY_Q,
    XSKP_ANY_H,
    XSKP_ANY_S,
    XSKP_ANY_D,     (*End of S1SKIPOPCODE subrange*)
    XSLR_0,
    XSLR_1,
    XSLR_2,
    XSLR_3,
    XSLR_4,
    XSLR_5,
    XSLR_6,
    XSLR_7,
    XSLR_8,
    XSLR_9,
    XSLR_10,
    XSLR_11,
    XSLR_12,
    XSLR_13,
    XSLR_14,
    XSLR_15,
    XSLR_16,
    XSLR_17,
    XSLR_18,
    XSLR_19,
    XSLR_20,
    XSLR_21,
    XSLR_22,
    XSLR_23,
    XSLR_24,
    XSLR_25,
    XSLR_26,
    XSLR_27,
    XSLR_28,
    XSLR_29,
    XSLR_30,
    XSLR_31,
    XSLRADR_0,
    XSLRADR_1,
    XSLRADR_2,
    XSLRADR_3,
    XSLRADR_4,
    XSLRADR_5,
    XSLRADR_6,
    XSLRADR_7,
    XSLRADR_8,
    XSLRADR_9,
    XSLRADR_10,
    XSLRADR_11,
    XSLRADR_12,
    XSLRADR_13,
    XSLRADR_14,
    XSLRADR_15,
    XSLRADR_16,
    XSLRADR_17,
    XSLRADR_18,
    XSLRADR_19,
    XSLRADR_20,
    XSLRADR_21,
    XSLRADR_22,
    XSLRADR_23,
    XSLRADR_24,
    XSLRADR_25,
    XSLRADR_26,
    XSLRADR_27,
    XSLRADR_28,
    XSLRADR_29,
    XSLRADR_30,
    XSLRADR_31,
    XSUB_S,
    XSUBV_S,
    XSUB_D,
    XSUBV_D,
    XTRANS_Q_Q,
    XTRANS_Q_H,
    XTRANS_H_Q,
    XTRANS_H_H,
    XTRANS_Q_S,
    XTRANS_H_S,
    XTRANS_S_Q,
    XTRANS_S_H,
    XTRANS_S_S,
    XTRANS_Q_D,
    XTRANS_H_D,
    XTRANS_S_D,
    XTRANS_D_Q,
    XTRANS_D_H,
    XTRANS_D_S,
    XTRANS_D_D,
    XXOR_Q);

HARDS1OPCODE = 0..4095;
S1SKIPOPCODE = XDSKP_EQL..XSKP_ANY_D;				(*28JUN79 PTZ*)

(*
OPNDTYPE = (ILLARITH, ILLCOMP,
	    TYPA, TYPM, TYPN, TYPB, TYPC, TYPS, TYPQ,
	    TYPH, TYPI, TYPD, TYPX, TYPR, TYPP, TYPJ);
*)
OPNDTYPE = (ILLARITH, ILLCOMP,
	    TYPUA, TYPUB, TYPUC, TYPUE, TYPQ, TYPH, TYPUI, TYPUJ, TYPUK,
	    TYPUL, TYPUM, TYPUN, TYPUP, TYPUQ, TYPUR, TYPUS);

MEMTYPE = (NON_SPACE, R_SPACE, M_SPACE);
S1PRECISION = (S1ILLEGAL, S1Q, S1H, S1S, S1D);
S1LENGTH = 0..8;    (*QW LENGTH OF A BASIC S1 PRECISION*)
S1OPFORMAT = (VFAKEOP, VTOP, VJOP, VXOP, VSOP);
ALIGNMENTBOUNDARY = 0..MAXALIGNBOUNDARY;

S1REGISTER = FIRSTS1REG..LASTS1REG;
SETOFS1REGS = set of S1REGISTER;	(*PEG*)
S1GBL = FIRSTS1GBL..LASTS1GBL;

S1ADDRESS = 0..MAXS1ADDR;
S1DISP = MINS1DISP..MAXS1DISP;
S1BITNUM = 0..35;
S1SKIPDISTANCE = MINSKPOFFSET..MAXSKPOFFSET;

BIT = 0..1;
TWOBITS = 0..3;
THREEBITS = 0..7;					(*DATASTRCH*)
EIGHTEENBITS =  0..262143;				(*DATASTRCH*)
IWDRNG = 0..3;						(*DATASTRCH*)
OPND_INTEGER = 0 .. 4095;				(*8MAR79 PTZ*)

S1RELADR = 0..1073741823;   (*2**30 - 1*)
ESDINDEX = 1..MAXESDINDEX;
ESRINDEX = 1..MAXESRINDEX;
ZINDEX =   1..MAXZINDEX;

BANK = integer  (*should be (RGS, MEM), but alignment*);
LINTVAL_OR_LINSTPTR = (LINTVAL,LINSTPTR);		(*DATASTRCH*)
XW_EV_OR_XW_C = (XW_EV,XW_C);
A_CODEREC = ↑CODEREC;
AN_INSTREC = ↑INSTREC;					(*DATASTRCH*)
AN_OPERANDXWORD = ↑OPERANDXWORD;			(*DATASTRCH*)
AN_OPNDXWORDREC = ↑OPNDXWORDREC;			(*DATASTRCH*)
AN_OPND2REC = ↑OPND2REC;				(*DATASTRCH*)
A_LBLHASHENT = ↑LBLHASHENT;
A_PROCENT = ↑PROCENT;
BITFIELD_LENGTH = 1..WORDBITS;
LBL_INDEX = -2..MAXLBL;   (* labels -2 to 0 reserved for SOPA use (DEF,XJP)  *)
NUMBER_OF_PAREGS = 0..MAXPAREG;
RNG_0_LBLHTSIZEM1 = 0..LBLHTSIZEM1;
DTYPE_LENGTH = integer;	(*bit length for valid UCode entities*)

INDIRECTION = (IND0, IND1, IND2);
SFLDRNG = 0..SFLDMAX;               (*VPA shift range*)

STKINX = MINSTKINX..MAXSTKINX;
FRAMEINX = MINFRAME..MAXFRAME;		(* peg 09jul79 *)

OPNDTYPE_TO_BOOLEAN_ARRAY =  array [OPNDTYPE] of boolean;

(*When *real* S1 words exist, this will just be an integer.*)
S1WORD =
    packed record					(*DATASTRCH*)
    LHALF :  EIGHTEENBITS;  (*DON'T change this without modifying*)
    RHALF :  EIGHTEENBITS;  (*assembly-coded GETFIELD, etc - PTZ*)
    end (*S1WORD*);


(*setch...*)
HOST_SET_EL_TYP = 0..HOST_SET_MAX;
HOST_SET_TYP = set of HOST_SET_EL_TYP;	(*Set available on host machine.*)

SET_EL_TYP   = 0..SET_MAX;
(*%IFF SET4*)
SETREP_INDEX = 0..SETREP_MAX;				
SETREP = array [SETREP_INDEX] of HOST_SET_TYP;		
	  (*SOPA-internal representation of full S1 set.*)
(*%ELSE*)
% SETREP = HOST_SET_TYP; \
(*%ENDC*)

S1SETREP_INDEX = 0..S1SETREP_MAX;
S1SETREP = array [S1SETREP_INDEX] of S1WORD;	(*S1 set representation.*)

SETPART_INDEX = 0..SETPART_MAX;
(*...setch*)

(*%IFT D10*)
(*%IFT ASCII*)
char = ascii;
(*%ENDC*)
(*%ENDC*)

CHAR2 = packed array [1..2] of char;
CHAR3 = packed array [1..3] of char;
CHAR4 = packed array [1..4] of char;
CHAR10 = packed array [1..10] of char;
CHAR12 = packed array [1..12] of char;
CHAR15 = packed array [1..15] of char;
CHAR17 = packed array [1..17] of char;
CHAR64 = packed array [1..64] of char;
ALFALEN = 1..ALFASIZE;
ALFA = packed array [ALFALEN] of char;
NAMEREC = record   NAM :  ALFA;  LEN :  ALFALEN   end;
STRINGTYPE = packed array [1..STRINGMAX] of char;	(*als/peg 24jul79*)
STRINX = 0..STRINGMAX;					(*als/peg 24jul79*)

NONNEGINT = 0..MAX_ON_COMP_MACH;

ZSYMBOL = packed array [1..8] of char;  (*external symbol name*)
ZSEGTYPE = (ZIS,ZDS,ZCM);
ZESDTYPE = (ZST,ZIN,ZDN,ZAN);
ZESRTYPE = (ZIR,ZDR,ZAR,ZXR);
ZOPR = (ZPLUS,ZMINUS);
ZESDESRSEG = (ZESD,ZESR,ZSEG);

OPNDNUM = (OPND1NUM,OPND2NUM);				(*DATASTRCH*)
INSTBUFINX = (S1INST,S1OPND2XWD,S1OPND1XWD);		(*DATASTRCH*)

CODEREC =
    record
    NEXTPTR :  A_CODEREC;
    CODEWORD :  S1WORD
    end (*CODEREC*);


INSTOPND =	(*packing tuned for PDP-10   2SEP79 PTZ*)	(*DATASTRCH*)
    packed record
    XWD :  AN_OPERANDXWORD;		 (*X field = 1 iff XWD ≠ nil*)
    REG :  S1REGISTER;
    F :  MINSHORTOFFSET..MAXSHORTOFFSET;
    end (*INSTOPND*);


INSTREC =	(*packing tuned for PDP-10   2SEP79 PTZ*)	(*DATASTRCH*)
    packed record
    PREVPTR : AN_INSTREC;	(*new list is doubly-linked*)
    NEXTPTR : AN_INSTREC;
    INSTOPND1 : INSTOPND;
    INSTOPND2 : INSTOPND;
    IWDS : IWDRNG;			(*# of S-1 words taken by this instr*)
    OPCODE : S1OPCODE;
    case OPFMT : S1OPFORMAT of
	VFAKEOP:(FAKEOPND : integer);
	VXOP:	( );
	VTOP:	(T : TWOBITS);
      VJOP,VSOP:(PR : BIT;
  		 DUMMYSPACE : THREEBITS;   (*make DESTPTR start on HW bndry*)
		 DESTPTR : AN_INSTREC;
		 case BIT of 
		    0:  (J : MINJPROFFSET..MAXJPROFFSET);
		    1:	(SKP : MINSKPOFFSET..MAXSKPOFFSET));
    end (*INSTREC*);


INSTREC_PTRINT =      (* a kludge for printing ptr values for debugging *)
    record							(*14JAN79 PTZ*)
    case BIT of
	0 : (PTR : AN_INSTREC);					(*DATASTRCH*)
	1 : (INT : integer);
    end (*INSTREC_PTRINT*);


OPNDXWORDREC =							(*DATASTRCH*)
    record
    NEXTPTR : AN_OPNDXWORDREC;
    XWORDPTR : AN_OPERANDXWORD;
    end(*OPNDXWORDREC*);


OPND2REC =							(*DATASTRCH*)
    record
    NEXTPTR : AN_OPND2REC;
    OPND2IPTR : AN_INSTREC;
    end(*OPND2REC*);


CODELIST =            (*linked via NEXTPTR*)
    record
    NWORDS :  0..MAXCODEW;
    FIRST, LAST :  A_CODEREC;
    end (*CODELIST*);


INSTLIST =							(*DATASTRCH*)
    record
    NWORDS : integer;			(*sum over all IWDS*)
    FIRST, LAST : AN_INSTREC
    end (*INSTLIST*);						(*DATASTRCH*)



JUMPLIST =
    record
    NWORDS :  0..MAXCODEW;
    FIRST, LAST :  AN_INSTREC;					(*DATASTRCH*)
    end (*JUMPLIST*);


OPNDXWORDFIXLIST =						(*DATASTRCH*)
    record
    NWORDS : integer;
    FIRST, LAST : AN_OPNDXWORDREC;
    end(*OPNDXWORDFIXLIST*);


OPND2FIXLIST =							(*DATASTRCH*)
    record
    NWORDS : integer;
    FIRST, LAST : AN_OPND2REC;
    end(*OPND2FIXLIST*);


RTSTACK =				(*peg 25jul79...*)
    record
    SIZE :  integer;
    FIXLIST, NEGFIXLIST :  OPND2FIXLIST;			(*KYW 9/5 79*)
    end (*RTSTACK*);			(*...peg 25jul79*)



LBLHASHENT =
    record
    LBLNUM :  LBL_INDEX;
    NEXTPTR :  A_LBLHASHENT;
    DEFINED :  boolean;
    BRANCH_CNT :  integer;	(* peg 02jul79 *)

    case LINTVAL_OR_LINSTPTR of
	LINTVAL : (INTVAL :  integer;  CLIST :  OPND2FIXLIST); (*DATASTRCH*)
	LINSTPTR : (INSTPTR :  AN_INSTREC;  JLIST :  JUMPLIST;
				    JUMPTABLELABEL :  boolean)	(*DATASTRCH*)
    end (*LBLHASHENT*);


PROCENT =
    record
    NAME :  ALFA;
    FIXLIST :  OPNDXWORDFIXLIST;				(*DATASTRCH*)
    NEXTPTR :  A_PROCENT
    end (*PROCENT*);


PROCSPEC =					(* peg 18jul79...*)
    record
    PROCTYPE :  OPNDTYPE;
    PROCNAM :  NAMEREC;
    PARMS_POPPED,
    RESULTS_PUSHED,
    REGPARMAREA,		(* in quarterwords *)
    R_MEMORY_AREA,		(* in bits...*)
    M_MEMORY_AREA :		(*...in bits *)
			    integer;
    end (*PROCSPEC*);				(*...peg 18jul79 *)



MSTENTRY =
    record
    DESTLEV :  1..MAXLVL;  (*level of callee*)
    CURPARMREGS :  NUMBER_OF_PAREGS;
		    (*number of parmregs used by caller*)
    EVALSAVESTART :  integer;
		    (*displacement into the evalsave of the
		      low end of the section used by this call*)
    MSTCODESTART :  AN_INSTREC; (*Start of code from MST	
				  (NEWINSTREC at entry to PMST)*) (*DATASTRCH*)
    end (*MSTENTRY*);



OPERANDXWORD = 		(*packing tuned for PDP-10   2SEP79 PTZ*)
    packed record
    case FMT :  XW_EV_OR_XW_C of
	XW_EV :  (P, V, D, I :  BIT;
		  S :  0..MAXINDEXSHIFT;
		  REG :  S1REGISTER;
		  ADDR :  S1ADDRESS;
		  DISP :  S1DISP  );
	XW_C :  (VAL :  S1WORD)

    end (*OPERANDXWORD*);


OPERAND =			(*could be 5 wds if packed, now 8 - 2SEP79 PTZ*)
    record
    FIXPTR :  A_PROCENT;  (*used only for XTRNSYMFIX*)
    FIXUP :  (NOFIX, STRINGFIX, SETFIX, REALFIX,
			     XTRNSYMFIX, BOUNDFIX);
    X :  BIT;
    REG :  S1REGISTER;
    F :  MINSHORTOFFSET..MAXSHORTOFFSET;
    XW :  OPERANDXWORD;
    end (*OPERAND*);


LVLDSP =
    record
    DSPLMT :  integer;
    LVL :  0..MAXLVL
    end (*LVLDSP*);



MEMOREG =
    record

    case WHICH : BANK of
	RGS :  (RGADR :  S1REGISTER);
	MEM :  (MEMADR :  LVLDSP)
    end (*MEMOREG*);



VPAREC =
    record

    VSHIFT :  SFLDRNG;      (*amount to shift part after
			     evaluation and indirection.*)
    VPAIND :  IND1..IND2;   (*indirection on this variable part.*)

    VPA :  MEMOREG;         (*memory or register location.*)

    end  (*VPAREC*);




(*Type DATUM is the crux of this program.  It represents a quantity on
the P-Machine stack during the process of executing the P-Code program
being translated.  This quantity can be constant, in which case we have
its value in the datum; it may be a variable, in which case we have its
address in register or memory; or it may be a computed value, in which
case we may have the address of a temporary register containing the
quantity, or we may have several of any of the above along with other
information which all together tells what computation is needed beyond
the code which has already been emitted in order to calculate the
quantity.

The process of evaluating a datum can be described as follows.  A
'MEMOREG' represents a register or memory address in the S1.  Unless
indirected, the quantity represented is that address; thus the value of
a FPA with LVL=1 and DSPLMT=100 is the *address* of the 100th unit after
the unit addressed by the level 1 display register.  We consider this a
constant even though it clearly depends on the run-time value of a
register.

If the MEMOREG is in a VPA, more may be done to it.  A VPA has an
indirection associated with it of either 1 or 2.  A VPA MEMOREG with
indirection 1 represents the quantity at the address described by the
MEMOREG.  If the indirection is 2, the MEMOREG describes an address
where there is another address.  The contents of the location at that
second address is the value of the quantity.  After the appropriate
indirection is done, there may be a shift applied to the quantity (e.g.
if it is to be an index).  Note that such a shift is applied after the
VPA indirection.

After the FPA and any active VPAs have been completely evaluated, we add
together their values and indirect the sum 0, 1, or 2 more times to get
the value of the datum itself.  Thus for example if FINALIND is 0 the
datum value is the sum of the part values; if FINALIND is 1 the sum is
the *address* of the datum value. *)

DATUM =
    record

    CODESTART :  AN_INSTREC; (*pointer to first S1 instruction	
			     in the evaluation of this datum*)	(*DATASTRCH*)
    DTYPE :  OPNDTYPE;

    DLENGTH :  DTYPE_LENGTH; (*bit length of item*)

    MTYPE :  MEMTYPE;

    (*The following five fields only apply to booleans.*)
    BREPRES :  (BINTVAL, BJUMP);
			    (*tells whether boolean is represented
			     as a 0..1 value or as jump structure*)
    BTRUELIST :  JUMPLIST;  (*list of jumps that are taken if the
			     datum is discovered to be true*)
    BFALSELIST :  JUMPLIST; (*list of jumps that are taken if the
			     datum is discovered to be false*)
    BFALLTHRUSKIPLOC :  AN_INSTREC;				(*DATASTRCH*)
			    (*loc of last skip around jump in
			     code to evaluate boolean*)
    BJUMPON :  boolean;     (*truth value for datum on which the
			     jump after the fallthruskip jumps*)
    (*End of special boolean fields.*)


    SCNST :  SETREP;       (*set value if set constant*)
    RCNST :  real;         (*real value if real constant*)

    FINALIND :  IND0..IND2;
	(*Final indirection depth of represented quantity.
	    IND0 : constant or constant wrt base.
	    IND1 : one indirection applied after evaluation.
	    IND2 : two indirections applied after evaluation.
	 FINALIND *must* be IND0 if there is no VPA
	 or if there is no FPA and only one VPA and that VPA
	 is at indirection IND1.  That is, an indirection
	 applied to an FPA is recorded by making it a VPA,
	 and an indirection applied to a single VPA with
	 small internal indirection is recorded by increasing
	 that internal indirection.*)

    FPA :  MEMOREG;         (*accumulated additive fixed part*)

    NVPAS :  0..2;          (*number of active VPAs.  If only 1,
			     VPA1 is the active one.*)

    VPA1 :  VPAREC;         (*variable parts : contents of the*)
    VPA2 :  VPAREC;         (*described register or memory loc.*)

    end (*DATUM*);

var

(*%IFT D10*)
    PRR : text;	
(*%ENDC*)
    OPC :  U_OPCODE;
    MNEM :  CHAR4;
    TYP :  OPNDTYPE;
    TYPO2 :  OPNDTYPE;
    MTYP:  MEMTYPE;
    I1, I2, I3, I4, I5, I6, I7 :  integer;			(*20JUL79 PTZ*)
    R1 :  real;
    P1 :  SETREP;
    NAM0, NAM1, NAM2 :	NAMEREC;
    SVAL :  STRINGTYPE;
    SLGTH :  STRINX;
    CLEN : 0..COMMLEN;						(*peg 24aug79*)
    COMMFIELD :  CHAR64;					(*peg 24aug79*)
    UNKT : boolean; (* To allow unknown UNK instructions *)
    SP_EXCESS,						(*SETPARMKLUDGE*)
    PWORDCOUNT,						(* als/peg 17jul79 *)
    PSTRCOUNT : NONNEGINT;				(* als/peg 13jul79 *)
    PREGS_ARCHIVED :  boolean;				(* als/peg 18jul79 *)

    TR_UCODE, TR_S1CODE, TR_SIMP, TR_PEEPHOLE,		(*14JAN79 PTZ*)
	TR_STACK, TR_MST %, TR_NEST\ :  boolean;	(* peg 18jul79 *)
    OLDINSTREC :  AN_INSTREC;					(*DATASTRCH*)
    OLDTOP :  STKINX;
    OLDMSTTOP :  0..MAXMST;
    UNKNOWN_LOC :  integer;

    ASM : boolean;
    DEBUG :  boolean;
    NO_JMPX_TO_JMPA_FLG :  boolean;			(*14JAN79 PTZ...*)
    NO_COLLAPSE_MOV_FLG :  boolean;
    NO_SKIP_JMPA_FLG :  boolean;			(*...14JAN79 PTZ*)
    NO_INC_SKP_FLG : boolean;				(*28JUN79 PTZ*)
    ASSERTCOUNT :  integer;
    CURPC :  integer;

    MAINCODE :	INSTLIST;					(*DATASTRCH*)
    NEWINSTREC :  AN_INSTREC;					(*DATASTRCH*)

    ERRINT1 :  integer;

    STRINGAREA :  CODELIST;
    NXTSTRDISP :  integer;
    STRINGAR_CPTR :  A_CODEREC;
    REALTBL, SETTBL, LOCTBL, BOUNDTBL :  CODELIST;
    STRINGFIXLIST, REALFIXLIST, SETFIXLIST :  OPNDXWORDFIXLIST;	(*DATASTRCH*)
    BOUNDFIXLIST :  OPNDXWORDFIXLIST;				(*DATASTRCH*)
    NEG_SHIFT_FIXLIST :  OPND2FIXLIST;				(*DATASTRCH*)
	(*Instructions on this list have OPND2s whose XW displacement
	  needs to be negated and shifted left at gen-segment time.*)
    STACKFRAME :  RTSTACK;	(*als/peg 25jul79*)
    EVALSAVE :  RTSTACK;
    PROCTBL :  record
		   NPROCS :  integer;
		   FIRST :  A_PROCENT
		   end (*PROCTBL*);
    LBLHASHTAB :  array [RNG_0_LBLHTSIZEM1] of A_LBLHASHENT;

    CSPHASHTAB :  array [0..CSPHTSIZEM1] of
			record
			CSPNAM :  NAMEREC;
			CSP :  P_STANDARDPROC
			end (*CSPHASHTAB*);

    OPCHASHTAB :  array [0..OPCHTSIZEM1] of
			record
			OPCNAM :  CHAR4;
			OPC :  U_OPCODE
			end (*OPCHASHTAB*);

 
    FIRSTTYPE, LASTTYPE :  OPNDTYPE;
    FIRSTMTYPE, LASTMTYPE, DEFAULTMTYPE :  MEMTYPE;
    FIRSTS1OP, LASTS1OP :  S1OPCODE;
    FIRSTSKIP, LASTSKIP :  S1OPCODE;
    ZERO_OP, EXTENDED_ZERO_OP :  OPERAND; (*specify constant 0*)
    EMPTY_OP :	OPERAND;   (*initted to valid but indeterminate value*)
    UNUSED_OP :	OPERAND;   (*specify R0 for unused operands*)
    ZEROS1WORD :  S1WORD;
    ZEROFPA :  MEMOREG;
    ZEROVPA :  VPAREC;
    ZERODATUM :  DATUM;
    EMPTYCODELIST :  CODELIST;
    EMPTYINSTLIST :  INSTLIST;					(*DATASTRCH*)
    EMPTYOPND2FIXLIST : OPND2FIXLIST;				(*DATASTRCH*)
    EMPTYOPNDXWORDFIXLIST : OPNDXWORDFIXLIST;			(*DATASTRCH*)
    EMPTYJUMPLIST :  JUMPLIST;
    OPNDRTB :  OPERAND;    (*specifies RTB*)
    OPNDRSP :  OPERAND;    (*specifies the SP*)
    SEG_EP_RELPC :  integer;   (*constant SEG_START_RELPC+SEG_EP_DISP*)

    NULL_SET : SETREP;	(*for empty-set comparison/assign.*) (*setch*)
    WHICHPART :  SETPART_INDEX;	(*for getting a particular piece of a
				  constant set out of the set table*)(*setch*)

    TWOEXP :  array [0..MAX_EXP_ON_COMP_MACH] of integer;

    CURPROG :  NAMEREC;
    CURPROC, MAXTMPPROC :  ALFA;
    CURPLOC, MAXTMPPLOC :  integer;
    CURLVL, MAXLVLUSED :  0..MAXLVL;
    CURPROCXN :  NAMEREC;
    DISPLAY :  S1REGISTER;

    OLDNP :  AN_INSTREC; (*saves heap top pointer so space can be 
			reclaimed after generation of segment*)(*DATASTRCH*)

    HARDOPCODE :  array [S1OPCODE] of HARDS1OPCODE;
    SOFTOPCODE :  array [HARDS1OPCODE] of S1OPCODE;
    REVERSE_OP :  array [S1OPCODE] of S1OPCODE;
    INVERSE_SKIP :  array [S1SKIPOPCODE] of S1OPCODE;		(*28JUN79 PTZ*)
    ISKPJMPA_OPCODE : array [S1OPCODE] of S1OPCODE;		(*28JUN79 PTZ*)
    DSKPJMPA_OPCODE : array [S1OPCODE] of S1OPCODE;		(*28JUN79 PTZ*)
    OPFORMAT :	array [S1OPCODE] of S1OPFORMAT;
    S1MNEM :  array [S1OPCODE] of CHAR15;
    DEST_PRECISION : array [S1OPCODE] of S1PRECISION;			(*PTZ*)
    COLLAPSIBLE_OP :  array [S1OPCODE] of boolean;			(*PBK*)
	(* indication of whether an XOP or TOP can be collapsed with a
	   following MOV*)                                                  (*PBK*)

    TYPECODE :	array [OPNDTYPE] of char;
    MTYPECODE :	array [MEMTYPE] of char;
    ALIGNBNDRY :  array [OPNDTYPE] of ALIGNMENTBOUNDARY;
    S1SIZE :  array [OPNDTYPE] of S1Q..S1D;
    FUNCUNITS :  array [OPNDTYPE] of S1LENGTH;

    IS_DOUBLE :  OPNDTYPE_TO_BOOLEAN_ARRAY;
    IS_SINGLE :  OPNDTYPE_TO_BOOLEAN_ARRAY;
    IS_INTEGER :  OPNDTYPE_TO_BOOLEAN_ARRAY;
    IS_REAL :  OPNDTYPE_TO_BOOLEAN_ARRAY;
    IS_SIGNED_NUM :  OPNDTYPE_TO_BOOLEAN_ARRAY;

    SKP_NON_X :	array [OPNDTYPE] of S1OPCODE;
    MOV_X_X :  array [OPNDTYPE] of S1OPCODE;
    ABS_X :  array [OPNDTYPE] of S1OPCODE;
    NEG_X :  array [OPNDTYPE] of S1OPCODE;
    MOVMQ_N :  array [1..MAXMOVMQ] of S1OPCODE;
    MOVMS_N :  array [1..MAXMOVMS] of S1OPCODE;		(*5DEC78 ALS*)
    FLOAT_S_X :  array [OPNDTYPE] of S1OPCODE;
    SLR_N :  array [S1REGISTER] of S1OPCODE;
    SLRADR_N :  array [S1REGISTER] of S1OPCODE;
    BTRP_B_X :	array [OPNDTYPE] of S1OPCODE;
    BTRP_N_X :  array [0..1, OPNDTYPE] of S1OPCODE;
    MOV_X_Y :  array [OPNDTYPE, OPNDTYPE] of S1OPCODE;

    ARITH_RESULT_TYPE :  array [OPNDTYPE, OPNDTYPE] of OPNDTYPE;
    COMPARE_COERCE_TYPE :  array [OPNDTYPE, OPNDTYPE] of OPNDTYPE;

    REAL_ARITH_OP :  array [S1S..S1D, UADD..UDIV] of S1OPCODE;
    COMPARE_OP :  array [S1Q..S1D, UEQU..ULES] of S1OPCODE;
    BLKCMP_X_Q :  array [UEQU..ULES] of S1OPCODE;

    RISFREE :  array [S1REGISTER] of boolean;
    RPWORD :  array [S1REGISTER] of 
	(RSINGLE, R1STOFPAIR, R2NDOFPAIR, R1STOFBLOCK, RINBLOCK);(*PBK*)(*PEG*)
    GISFREE :  array [S1GBL] of boolean;

    NXTRG :  S1REGISTER;
    MINTMPS1REG, MAXTMPS1REG, MINDSPS1REG :  S1REGISTER;
    RTBUSER :  STKINX;	(*stack index for datum using RTB*)
    RTBDOUB :  boolean; (*true iff RTBUSER is a doubleword quantity*)
    LVL_TO_S1REG :  array [1..MAXLVL] of S1REGISTER;
    PRM_TO_S1REG :  array [0..MAXPAREGM1] of S1REGISTER;
    S1REG_TO_PRM :  array [S1REGISTER] of integer;

    ZSEGTYPE_TO_CHARS :  array [ZSEGTYPE] of CHAR4;
    ZESDTYPE_TO_CHARS :  array [ZESDTYPE] of CHAR4;
    ZESRTYPE_TO_CHARS :  array [ZESRTYPE] of CHAR4;
    ZIXFLAG_TO_CHAR : array [ZESDESRSEG] of char;
    ZOPR_TO_CHARS : array [ZOPR] of CHAR2;

    LOCALSIZELNUM :  LBL_INDEX;

    ALL_CODE_EMITTED :  boolean;				(*DATASTRCH*)
    JUMPS_CONCRETIZED :  boolean;
    JUMPTABLE_IN_PROGRESS :  boolean;


    STK :  array [STKINX] of DATUM;
    BOT, TOP :  STKINX;		(*BOT changed to var -- peg 09jul79*)

    STKFRAME :  array [FRAMEINX] of STKINX;	(* peg 09jul79 *)
    CURFRAME :  FRAMEINX;			(* peg 09jul79 *)

    MSTSTK :  array [0..MAXMST] of MSTENTRY;
    MSTTOP :  0..MAXMST;

    BLOCKTABLE : array [MINBLOCK..MAXBLOCK] of ILLBLOCKNO..MAXLVL;

    CURPROCSPEC :  PROCSPEC;			(* peg 18jul79 *)

    TIMER :  integer;
    ERRORCNT :	NONNEGINT;

    S1OP_CNT :  array [S1OPCODE] of integer;				(*LCW*)
    S1OP_TOT :  integer;						(*LCW*)
    S1OP :  S1OPCODE;							(*LCW*)

    WORD_CNT : integer;							(*LCW*)

    PEEP_PASSES :  integer;						(*PTZ*)

    INSTR_WDS_REMOVED : integer;					(*PTZ*)
    J_TO_J_CNT : integer;						(*PBK*)
    JMPAS_REMOVED_FROM_SKIPS : integer;					(*PTZ*)
    MOV_COLLAPSE : array [1..14] of integer;			(*21JUN79 PTZ*)
    MOVS_COLLAPSED : integer;						(*PTZ*)
    INC_SKP_COLLAPSE : array [1..3] of integer;			(*29JUN79 PTZ*)
    INC_SKPS_COLLAPSED : integer;				(*2JUL79 PTZ*)
    ICNT : integer;						(*21JUN79 PTZ*)
    S1INSTBUF : array [INSTBUFINX] of S1WORD;			(*DATASTRCH*)
    TOTAL_STORAGE : integer;					(*31AUG79 PTZ...*)
    NUM_PROCS_COMPILED : integer;
    MAX_STORAGE : integer;					(*...31AUG79 PTZ*)
    ICUPSEEN : boolean;	
    PSWITCHNAME : alfa;
(** ERROR_CLASS:	ERREXIT ASSERTFAIL ERROR **)
(**)

function FLDW(NUM :  integer) :  integer;
    forward;


procedure ERREXIT (CODE :  integer);
    begin
    WRITELN(OUTPUT,'** * ERREXIT called with code =',CODE);
(*%IFT D10*)
    HALT	
(*%ELSE*)
%  EXIT(4097)	\
(*%ENDC*)
    end;

procedure ASSERTFAIL(MSG :	CHAR12);			(* ALS*)
    (*ASSERTFAIL is used for internal consistency checking of the program.
     The BOOLEAN that is a parameter in the ASSERT calls is here tested
     before calling ASSERTFAIL, to avoid needless procedure calls.
     The message in MSG is printed (to identify the particular
     assertion) togather with an assertion count (now only a count of
     the failed assertions) and execution is terminated.  Note, that as it
     is, only one failure will be reported.  By not EXITTing one might get
     more information from an attempted compilation.*)
    begin
    ASSERTCOUNT := ASSERTCOUNT + 1;
	WRITELN(OUTPUT);
	WRITELN(OUTPUT);
	WRITELN(OUTPUT,'** ** ERROR ** **  Assertion #',ASSERTCOUNT:6,
		       ' failed :  ',MSG,'  ** **');
(*	ASSERTCOUNT := ASSERTCOUNT div (ASSERTCOUNT-ASSERTCOUNT); 17JAN79 EJG*)
	ERREXIT(9999)
    end (*ASSERTFAIL*);

procedure ERROR(CODE :	ERRORCODE);
    (*This procedure is called whenever an error condition is detected
     in the input U-Code.  At the very least, it prints a message
     describing the error.  For the time being, it then gives up the
     ghost and halts execution.*)

    begin

    ERRORCNT := ERRORCNT + 1;
    WRITE(OUTPUT,' *ERROR*  ');

    case CODE of

	WARITH_ON_WRONG_DT :
	    begin
	    WRITELN(OUTPUT,'Arith on wrong data type')
	    end;

	WNOT_IMPLEMENTED :
	    begin
	    WRITELN(OUTPUT,'Not yet implemented')    (*pn*)
	    end;

	WILLEGAL_LABEL :
	    begin
	    WRITELN(OUTPUT,'Illegal label number or format')
	    end;

	WABS_OR_NEG_OF_NONSIGNED :
	    begin
	    WRITELN(OUTPUT,'ABS or NEG applied to non-signed number')
	    end;

	WADDR_OUT_OF_RANGE :
	    begin
	    WRITELN(OUTPUT,
		'Fixed-up address exceeds 30-bit S1 address space')
	    end;

	WADDRESS_CHECK_ON_NONADDRESS :
	    begin
	    WRITELN(OUTPUT,'CHK type A applied to non-address')
	    end;

	WALIGNMENT_ERROR :
	    begin
	    WRITELN(OUTPUT,'Alignment error')
	    end;

	WANDOR_NEEDS_BOOLEAN :
	    begin
	    WRITELN(OUTPUT,'AND or IOR applied to non-boolean')
	    end;

	WBGN_STP_NAME_MISMATCH :
	    begin
	    WRITELN(OUTPUT,
		'Name parameters of BGN and STP do not match')
	    end;

	WENT_AND_PLOD_INCONSISTENT :
	    begin
	    WRITELN(OUTPUT,
		'Type parameters of ENT and PLOD do not match')
	    end;

	WENT_END_NAME_MISMATCH :
	    begin
	    WRITELN(OUTPUT,
		'Name parameters of ENT and END do not match')
	    end;

	WENT_SPECIFIED_WRONG_PARMS :
	    begin
	    WRITELN(OUTPUT,
		'ENT specified wrong number of parameters')
	    end;

	WBINARY_OPND_TYPE_CONFLICT :
	    begin
	    WRITELN(OUTPUT,
	    'Invalid or conflicting operand types for binary operation')
	    end;

	WBOOL_IS_TRUE :
	    begin
	    WRITELN(OUTPUT, 'CHKF: Boolean found to be not false')
	    end;

	WBOOL_NOT_TRUE :
	    begin
	    WRITELN(OUTPUT, 'CHKT: Boolean found to be not true')
	    end;

	WCHECKED_CONSTANT_OUT_OF_RANGE :
	    begin
	    WRITELN(OUTPUT,
		'CHK constant operand out of specified range')
	    end;

	WCHKF_CHKT_NEEDS_BOOLEAN :
	    begin
	    WRITELN(OUTPUT,'CHKF or CHKT needs boolean')
	    end;

	WCHKN_NULL_TOP :
	    begin
	    WRITELN(OUTPUT,'CHKN Top of stack is the nil pointer')
	    end;

	WCHKN_NOT_ADDRESS :
	    begin
	    WRITELN(OUTPUT,'CHKN Top of stack not an address')
	    end;

	WCHECKING_INVALID_TYPE :
	    begin
	    WRITELN(OUTPUT,'CHK applied to invalid operand type')
	    end;

	WCHR_NEEDS_INT :
	    begin
	    WRITELN(OUTPUT,'CHR applied to non-integer')
	    end;

	WCOERCION_INVALID :
	    begin
	    WRITELN(OUTPUT,'Invalid type coercion')
	    end;

	WCOMPARE_ILLEGAL :
	    begin
	    WRITELN(OUTPUT,
	 'Invalid or conflicting operand types for compare operation')
	    end;

	WCOMPM_NEEDS_ADDR :
	    begin
	    WRITELN(OUTPUT,'Compare type M applied to non-address')
	    end;

	WCONST_OUT_OF_RANGE_FOR_SET :
	    begin
	    WRITELN(OUTPUT,'Constant is out of range for set')
	    end;

	WDISP_OUT_OF_RANGE :
	    begin
	    WRITELN(OUTPUT,
		'Fixed-up displacement exceeds 25 bit S1 limit')
	    end;

	WDUP_ON_EMPTY_STACK :
	    begin
	    WRITELN(OUTPUT,'DUP with empty stack')
	    end;

	WEQU_etc_with_TYP_is_TYPM :
	    begin
	    WRITELN(OUTPUT,'EQU..NEQ with TYP=TYPUM in UCODE')
	    end;

	WEXPR_TOO_COMPLEX :
	    begin
	    WRITELN(OUTPUT,
	    'Expression too complex (or total proc nesting too deep)')
	    end;

	WFILE_ADDRESS_NEEDED :
	    begin
	    WRITELN(OUTPUT,'Stack top must be file address')
	    end;

	WTJP_FJP_NEEDS_BOOLEAN :
	    begin
	    WRITELN(OUTPUT,'TJP or FJP with non-boolean stack top')
	    end;

	WTJP_FJP_WITH_NONEMPTY_STACK :
	    begin
	    WRITELN(OUTPUT,'TJP or FJP with non-singleton expr stack')
	    end;

	WFIX_OF_INVALID_TYPE :
	    begin
	    WRITELN(OUTPUT,'RND applied to invalid operand type')
	    end;

	WFLOAT_OF_INVALID_TYPE :
	    begin
	    WRITELN(OUTPUT,
		'FLO or FLT applied to invalid operand type')
	    end;

	WFUNC_CALLS_NESTED_TOO_DEEPLY :
	    begin
	    WRITELN(OUTPUT,
		'Function calls nested too deeply in expression')
	    end;

	WIEQU_etc_with_TYP_not_TYPM :
	    begin
	    WRITELN(OUTPUT,'IEQU..INEQ with TYP<>TYPUM in UCODE')
	    end;

	WILLEGAL_PROC_TYPECODE :
	    begin
	    WRITELN(OUTPUT,
		'Invalid procedure type in U-Code instruction')
	    end;

	WINCOMPATIBLE_TYPES :
	    begin
	    WRITELN(OUTPUT,'Incompatible types for storing')
	    end;

	WINDEX_WITHOUT_BASE :
	    begin
	    WRITELN(OUTPUT,'IND on (shifted) index without base')
	    end;

	WINDEXING_IN_PARMS :
	    begin
	    WRITELN(OUTPUT,
		'Indexing within fast (register) parameter area')
	    end;

	WINN_REQUIRES_SET_ON_TOP_OF_STACK :
	    begin
	    WRITELN(OUTPUT,'INN on non-set second operand')
	    end;

	WINSTR_TYPE_NOT_DATUM_TYPE :
	    begin
	    WRITELN(OUTPUT, 'Type in U-Code command different',
			    ' from type of stack top.')
	    end;

	WINSUFF_PARMS_SPECIFIED :
	    begin
	    WRITELN(OUTPUT,
		'CUP specified fewer parameters than are on stack')
	    end;

	W2_MANY_PARMS_SPECIFIED :
	    begin
	    WRITELN(OUTPUT,
		'CUP specified more parameters than are on stack')
	    end;

	WINTEGER_CONSTANT_DIV_MOD_BY_ZERO :
	    begin
	    WRITELN(OUTPUT,'DVI or mod by integer constant zero')
	    end;

	WINVAL_BLOCK_NUMBER :
	    begin
	    WRITELN(OUTPUT, 'Invalid memory block number')
	    end;

	WINVAL_CSP :
	    begin
	    WRITELN(OUTPUT, 'Invalid standard procedure name')
	    end;

	WINVAL_OPC :
	    begin
	    WRITELN(OUTPUT, 'Invalid U-Code opcode:',MNEM)
	    end;

	WINVAL_TRACE :
	    begin
	    WRITELN(OUTPUT, 'Invalid trace argument')
	    end;

	WINVAL_U_TYPECODE :
	    begin
	    WRITELN(OUTPUT, 'Invalid type in U-Code instruction')
	    end;

	WINVAL_TYP_ON_LDC :
	    begin
	    WRITELN(OUTPUT,'LDC type argument invalid')
	    end;

	WINVALID_DISPLACEMENT :
	    begin
	    WRITELN(OUTPUT,
		'Fixed-up displacement exceeds 25 bit S1 limit')
	    end;

	WINVALID_TYPE_COERCION :
	    begin
	    WRITELN(OUTPUT,'Invalid type coercion')
	    end;

	WINVALID_LEVEL :
	    begin
	    WRITELN(OUTPUT, 'Invalid level in U-Code instruction')
	    end;

	WINVALID_MEMORY_TYPE :
	    begin
	    WRITELN(OUTPUT, 'Invalid memory type in U-Code instruction')
	    end;

	WIXA_NEEDS_ADDR :
	    begin
	    WRITELN(OUTPUT,'IXA on non-address first operand')
	    end;

	WLAST_SST_PARM_TOO_BIG :
	    begin
	    WRITELN(OUTPUT, 'Last SST parameter bigger than MAXPAREG')
	    end;

	WL_LPTR_LBLNUM_UNDEFINED :
	    begin
	    WRITELN(OUTPUT,
		'Undefined label :  L',ERRINT1:FLDW(ERRINT1))
	    end;

	WLOADING_STRING :
	    begin
	    WRITELN(OUTPUT,
	 'IND loading string (indirect thru string constant illegal)')
	    end;

	WISTR_INST_NEEDS_ADDRS :
	    begin
	    WRITELN(OUTPUT,'ISTR or INST with non-address operand')
	    end;

	WMOV_NEEDS_ADDRS :
	    begin
	    WRITELN(OUTPUT,'MOV with non-address operand(s)')
	    end;

	WMST_SPECIFIED_INSUFF_PARM_STORAGE :
	    begin
	    WRITELN(OUTPUT,
		'MST specified insufficient parameter storage')
	    end;

	WMST_WITHOUT_CUP_IN_LAST_SEGMENT :
	    begin
	    WRITELN(OUTPUT,
		'MST without corresponding CUP in last segment')
	    end;

	WMULT_DEFINED_LAB :
	    begin
	    WRITELN(OUTPUT,'Multiply defined label')
	    end;

	WNESTING_TOO_DEEP_OR_EXPRESSION_TOO_COMPLEX :
	    begin
	    WRITELN(OUTPUT,
	     'Total proc nesting too deep (or some expr too complex)')
	    end;

	WNEW_MUST_HAVE_ADDR_AND_INT :
	    begin
	    WRITELN(OUTPUT,
		'NEW operands not (1) address and (2) integer')
	    end;

	WNOT_AN_ADDR :
	    begin
	    WRITELN(OUTPUT,'ILOD applied to non-address type')
	    end;

	WNOT_DISCRETE_TYPE :
	    begin
	    WRITELN(OUTPUT,
		'INC, DEC, PRE, or SUC applied to non-discrete type')
	    end;

	WNOT_NEEDS_BOOLEAN :
	    begin
	    WRITELN(OUTPUT,'NOT applied to non-boolean')
	    end;

	WNULLREF :
	    begin
	    WRITELN(OUTPUT,'IND applied to nil')
	    end;

	WODD_REQUIRES_AN_INTEGER :
	    begin
	    WRITELN(OUTPUT,'ODD applied to non-integer')
	    end;

	WORD_NEEDS_INT_BOOLEAN_OR_CHAR :
	    begin
	    WRITELN(OUTPUT,
		'ORD operand not integer, boolean, or char')
	    end;

	WPOP_OF_EMPTY_STACK :
	    begin
	    WRITELN(OUTPUT,
		'Pop of empty expr stack (stack underflow)')
	    end;

	WREAL_CONSTANT_DIVISION_BY_ZERO :
	    begin
	    WRITELN(OUTPUT,'DVR by real constant zero')
	    end;

	WREGPARMS_SPEC_TOO_LOW_IN_MST :
	    begin
	    WRITELN(OUTPUT,
	      'MST specified insufficient register parameter storage')
	    end;

	WROUND_OF_NON_REAL :					(*ROUND...*)
	    begin
	    WRITELN(OUTPUT,'Round of non-real quantity')
	    end;						(*...ROUND*)

	WRST_NEEDS_ADDR :
	    begin
	    WRITELN(OUTPUT,'RST operand not address')
	    end;

	WSAV_NEEDS_ADDR :
	    begin
	    WRITELN(OUTPUT,'SAV operand not address')
	    end;

	WSET_OPERATION_ON_NONSET_TYPES :
	    begin
	    WRITELN(OUTPUT,'Set operation applied to non-set')
	    end;

	WSGS_OR_INN_REQUIRES_INT_CHAR_OR_BOOLEAN :
	    begin
	    WRITELN(OUTPUT,
	   'SGS or INN (first) operand not integer, boolean, or char')
	    end;

	WSIO_DIDNT_SEE_FILEADDR :
	    begin
	    WRITELN(OUTPUT,'SIO didnt see file addr')
	    end;

	WSIO_WITH_NONADDRESS :
	    begin
	    WRITELN(OUTPUT,'SIO operand not address')
	    end;

	WSQUARE_OF_INVALID_TYPE :
	    begin
	    WRITELN(OUTPUT,'SQR operand type invalid')
	    end;

	WSTACK_LEFT_NONEMPTY_IN_LAST_SEGMENT :
	    begin
	    WRITELN(OUTPUT,'Expr stack left nonempty in last segment')
	    end;

	WSTACK_NON_EMPTY :
	    begin
	    WRITELN(OUTPUT, 'Expression stack should have been ',
			    'empty after last instruction')
	    end;

	WSTACK_NOT_SINGLE :
	    begin
	    WRITELN(OUTPUT, 'Expression stack should have ',
			    'contained exactly one element ',
			    'after last instruction')
	    end;

	WSWP_NOT_2 :
	    begin
	    WRITELN(OUTPUT,'SWP with less than 2 DATUMs on STACK')
	    end;

	WSWP_TYP_ERROR :
	    begin
	    WRITELN(OUTPUT,'SWP operand types specified incorrectly')
	    end;

	W2_MANY_BGNBS :
	    begin
	    WRITELN(OUTPUT,
		'Too many BGNB instructions encountered: stack overflow')
	    end;

	W2_MANY_ENDBS :
	    begin
	    WRITELN(OUTPUT,
		'Too many ENDB instructions encountered: stack underflow')
	    end;

	WTOO_LARGE_K_OR_L :
	    begin
	    WRITELN (OUTPUT,'Too large non-neg. integer')
	    end;

	WTRUNCATE_OF_INVALID_TYPE :
	    begin
	    WRITELN(OUTPUT,'TRC operand type invalid')
	    end;

	WCVT_WITH_INVALID :
	    begin
	    WRITELN(OUTPUT,'CVT or CVT2 instruction with invalid dtype')
	    end;

	WTYP_WITH_INVALID :
	    begin
	    WRITELN(OUTPUT,'TYP or TYP2 instruction with invalid dtype')
	    end;

	WUJP_WITH_NONEMPTY_STACK :
	    begin
	    WRITELN(OUTPUT,'UJP with nonempty expr stack')
	    end;

	WWRONG_COMPARE :
	    begin
	    WRITELN(OUTPUT,
		'Wrong compare operator for given operand types')
	    end;

	WWRONG_INSTR_DATATYPE :
	    begin
	    WRITELN(OUTPUT,
		'Invalid data type for this instruction')
	    end;

	WWRONG_RESULT_NUMBER :
	    begin
	    WRITELN(OUTPUT,
		'CUP instruction specified wrong number of function',
		' results--(no value-result parmeters allowed');
	    end;

	WXJP_WITHOUT_SINGLETON_STACK :
	    begin
	    WRITELN(OUTPUT,'XJP with non-singleton expr stack')
	    end

	end (*case*);

    if not (FALSE) then
        ASSERTFAIL('ERROR    999'); (*temporary to get traceback*)
    ERREXIT(1000)	(*Basic giving-up-the-ghost action.*)

    end (*ERROR*);
(** DEBUGGING_CLASS:	PRINTSET PRINTMEMOREG PRINTDATUM PRINT_NESTITEM PRINT_MSTENTRY PRINTNXTINST PRINTNAM PRINTTYP PRINTMTYP PRINTINT **)
(**)

function IS_CONSTANT (STE :  STKINX) :	boolean;
    forward;


procedure DISASSEMBLE(var CURPC :  integer; IPTR :  AN_INSTREC);(*DATASTRCH*)
    forward;


function SET_IN(SET_EL :  SET_EL_TYP; PSET :  SETREP) :  boolean;
    forward;


procedure PRINTSET (S :  SETREP);
    (*Print the set.*)

    var I :  SET_EL_TYP;		(*setch*)
	COUNT :  integer;

    begin
    WRITE (OUTPUT, ' [');
    COUNT := 0;
    for I := 0 to SET_MAX do
	if SET_IN(I,S) then		(*setch*)
	    begin
	    if COUNT > 15 then		(*setch*)
		begin
		WRITELN(OUTPUT);
		WRITE (OUTPUT, '		 ');
		COUNT := 0;
		end;
	    WRITE (OUTPUT, I : 4);
	    COUNT := COUNT + 1;
	    end;
    WRITELN (OUTPUT, '].');
    end (*PRINTSET*);


procedure PRINTSTRING(var STRVAL :  STRINGTYPE; var STRLGTH :  STRINX);
    (*Print a string from STRVAL -- als/peg 24jul7.*)

    var I :  STRINX;

    begin
    for I := 1 to STRLGTH do
	WRITE (OUTPUT, STRVAL[I]);
    end (*PRINTSTRING*);
 
procedure PRINTSCONST(var STRVAL :  STRINGTYPE; var STRLGTH :  STRINX);
   (*Print a string from STRVAL as a quoted string constant -- PN *)

    var I :  STRINX;

    begin
    WRITE (OUTPUT,' ''');
    for I := 1 to STRLGTH do
        begin
	WRITE (OUTPUT, STRVAL[I]);
	if STRVAL[I] = '''' then WRITE (OUTPUT, STRVAL[I]);
        end;
    WRITE (OUTPUT,'''');
    end (*PRINTSTRING*);
 

procedure PRINTMEMOREG (var X :  MEMOREG);
    (*Print the memoreg without changing lines.*)

    begin
    if X.WHICH = RGS then
	begin
	if X.RGADR = S1RTA then
	    WRITE (OUTPUT, 'RTA')
	else if X.RGADR = S1RTB then
	    WRITE (OUTPUT, 'RTB')
	else
	    WRITE (OUTPUT, 'R', ord(X.RGADR) : FLDW(ord(X.RGADR)) )
	end
    else if X.MEMADR.LVL = 0 then
	WRITE (OUTPUT, X.MEMADR.DSPLMT : FLDW(X.MEMADR.DSPLMT) )
    else
	WRITE (OUTPUT, '<L', X.MEMADR.LVL : FLDW(X.MEMADR.LVL),
	       ',', X.MEMADR.DSPLMT : FLDW(X.MEMADR.DSPLMT), '>' );
    end (*PRINTMEMOREG*);


procedure PRINTDATUM (STE :  STKINX);
    (*Print the datum for trace or debugging purposes.*)

    var PTR :  AN_INSTREC;					(*DATASTRCH*)
	I : integer;
	UNKNOWN_LOC :  integer;

    begin
    with STK[STE] do
	begin
	WRITELN (OUTPUT, '	   STK[', STE : FLDW(STE), '] IS' );
	WRITE (OUTPUT, '	 TYP', TYPECODE[DTYPE], ' = ');

	if (DTYPE = TYPUR) and IS_CONSTANT(STE) then
	    WRITELN (OUTPUT, RCNST)

	else if (DTYPE = TYPUS) and IS_CONSTANT(STE) then
	    PRINTSET (SCNST)

	else if (DTYPE = TYPUB) and (BREPRES = BJUMP) then
	    begin
	    WRITELN (OUTPUT, 'BJUMP with', BTRUELIST.NWORDS : 3,
		   ' true jumps and', BFALSELIST.NWORDS : 3,
		   ' false jumps.' );
	    WRITE (OUTPUT, '	     BJUMPON is ');
	    if BJUMPON then WRITE (OUTPUT, 'TRUE')
		       else WRITE (OUTPUT, 'FALSE');
	    WRITELN (OUTPUT, ' and fall thru skip is');
	    UNKNOWN_LOC := 0;
	    DISASSEMBLE (UNKNOWN_LOC, BFALLTHRUSKIPLOC);
	    PTR := BTRUELIST.FIRST;
	    for I := 1 to BTRUELIST.NWORDS do
		begin
		if not ( PTR <> nil) then ASSERTFAIL('PRINTDATU001');
		PTR := PTR↑.DESTPTR;			(*DATASTRCH*)
		end;
	    PTR := BFALSELIST.FIRST;
	    for I := 1 to BFALSELIST.NWORDS do
		begin
		if not ( PTR <> nil) then ASSERTFAIL('PRINTDATU002');
		PTR := PTR↑.DESTPTR;			(*DATASTRCH*)
		end;
	    end

	else
	    begin
	    WRITE (OUTPUT, ord(FINALIND) : 1, ': (' );
	    PRINTMEMOREG (FPA);
	    if NVPAS > 0 then
		begin
		WRITE (OUTPUT, ', ', ord(VPA1.VPAIND) : 1, ': (' );
		PRINTMEMOREG (VPA1.VPA);
		WRITE (OUTPUT, ')*', TWOEXP[VPA1.VSHIFT] : 1 );
		end;
	    if NVPAS = 2 then
		begin
		WRITE (OUTPUT, ', ', ord(VPA2.VPAIND) : 1, ': (' );
		PRINTMEMOREG (VPA2.VPA);
		WRITE (OUTPUT, ')*', TWOEXP[VPA2.VSHIFT] : 1 );
		end;
	    WRITELN (OUTPUT, ').' );
	    end;

	WRITE (OUTPUT,
		'	  Code starts with the instruction ');
	if CODESTART = NEWINSTREC then
	    WRITELN (OUTPUT, 'at NEWINSTREC.')
	else if CODESTART = nil then
	    writeln (OUTPUT, '??? NIL pointer.')
	else
  	    WRITELN (OUTPUT, S1MNEM[CODESTART↑.OPCODE] );	(*DATASTRCH*)
	end (*with*);
    end (*PRINTDATUM*);



%procedure PRINT_NESTITEM (INDEX :  integer);	(*commented out by*)
    (*Print NESTDISPLAY[INDEX].*)		(* peg 18jul79 *)

    begin
    with NESTDISPLAY[INDEX] do
	begin
	WRITELN (OUTPUT, ' NESTDISPLAY[',
		 INDEX : FLDW(INDEX), '] IS' );
	WRITELN (OUTPUT, ' ', PROCNAM.NAM, ' TYP', TYPECODE[PROCTYPE],
		 '  areas ', REGPARMAREA, FIRSTPARMAREA,
		 L_MEMORY_AREA, M_MEMORY_AREA );
	WRITELN (OUTPUT, ' displacements', LCBEFPAR,
		 OFFSET_IN_VARS, LOCALDATAOFFSET,
		 LOCALDATATRANSLATION );
	end (*with*);
    end (*PRINT_NESTITEM*);	\(*end comment out*)



procedure PRINT_MSTENTRY (INDEX :  integer);
    (*Print MSTSTK[INDEX].*)

    begin
    with MSTSTK[MSTTOP] do
	begin
	WRITELN (OUTPUT, ' MSTSTK[',
		 INDEX : FLDW(INDEX), '] is' );
	WRITELN (OUTPUT, ' lev', DESTLEV : 2,
		 ',  pregs', CURPARMREGS : 3 );
	WRITELN (OUTPUT,
		 ' evalsave', EVALSAVESTART : FLDW(EVALSAVESTART));
	end (*with*);
    end (*PRINT_MSTENTRY*);



procedure PRINTNXTINST;
    (*Print next P-Code instruction.*)

    var I: integer;

    procedure PRINTNAM (var NAM : NAMEREC);
	(*Print two spaces and the name.*)
	var I :  ALFALEN;
	begin
	WRITE (OUTPUT, '  ');
	for I := 1 to NAM.LEN do WRITE (OUTPUT, NAM.NAM[I]);
	end (*PRINTNAM*);

    procedure PRINTTYP (TYP :  OPNDTYPE);
	(*Print two blanks and the type code.*)
	begin
	WRITE (OUTPUT, '  ', TYPECODE[TYP]);
	end (*PRINTTYP*);


    procedure PRINTMTYP (TYP :  MEMTYPE);
	(*Print two blanks and the memory type code.*)
	begin
	WRITE (OUTPUT, '  ', MTYPECODE[TYP]);
	end (*PRINTTYP*);


    procedure PRINTINT (I : integer);
	(*Print two blanks and the integer.*)
	begin
	WRITE (OUTPUT, '  ', I : FLDW(I));
	end (*PRINTINT*);


    begin
    if (OPC = ULAB) or (OPC = UENT) or (OPC = UCLAB) or (OPC = USYM) then
	PRINTNAM (NAM0)
    else
	WRITE (' ');
    WRITE (OUTPUT, '  ', MNEM);

    case OPC of

	UCHKF, UCHKN, UCHKT, URET :
		(*null case*);

	UCLAB, ULAB, UMST, UNEW, UPLEX, UTJP :
		PRINTINT (I1);

	UEXPP, UIMPP, UIMPV :
		begin
		PRINTINT (I1);
		PRINTNAM (NAM1);
		end;
		
	ULEX :  begin
		PRINTINT (I1);
		PRINTINT (I2);
		end;

	ULDP :	begin
		PRINTINT (I1);
		PRINTINT (I2);
		PRINTNAM (NAM1);
		end;
		

	ULOC :  begin
		PRINTINT (I1);
		PRINTINT (I2);
		PRINTINT (I3);
		PRINTINT (I4);
		end;


	UEND :	PRINTNAM (NAM1);

	UBGN, UFJP, UUJP, USTP : 
		PRINTNAM (NAM1);

	UOPTN :	begin
		PRINTNAM (NAM1);
		PRINTINT (I1);
		end;

	UABS, UADD, USUB, UMPY, UDIV, UAND, UDIF, UDMD, UDSP, UDUP, 
	UEQU, UNEQ, UGEQ, UGRT, ULEQ, ULES, UIEQU,UINEQ,UIGEQ,UIGRT,
	UILEQ,UILES,UINN, UINT, UIOR, UMOD, UMUS, UNEG, UNOT, UODD, 
	USDEF,USGS, USQR, UUNI :
		PRINTTYP (TYP);

	UCVT, UCVT2, URND, USWP, UTYP, UTYP2 :
		begin
		PRINTTYP (TYP);
		PRINTTYP (TYPO2);
		end;

	UDEC, UINC, UIXA, UMOV :
		begin
		PRINTTYP (TYP);
		PRINTINT (I1);
		end;

	UCHKL, UCHKH :
		begin
		PRINTTYP (TYP);
		if TYP = TYPUC then
		    PRINTSCONST(SVAL, SLGTH)
		else PRINTINT (I1);
		end;

	UADJ, UICUP, UILOD, UINST, UISTR:
		begin
		PRINTTYP (TYP);
		PRINTINT (I1);
		PRINTINT (I2);
		end;


        UENT :	begin
		PRINTTYP (TYP);
		PRINTINT (I1);
		PRINTINT (I2);
		PRINTINT (I3);
		PRINTINT (I4);
		end;


	UDEF :  begin
		PRINTMTYP (MTYP);
		PRINTINT (I1);
		end;


	UDEAD, UDOA, UEXPV, ULDA, ULIVE, USYM :
		begin
		PRINTMTYP (MTYP);
		PRINTINT (I1);
		PRINTINT (I2);
		PRINTINT (I3);
		end;

	UMDEF :	begin
		PRINTMTYP (MTYP);
		PRINTINT (I1);
		PRINTINT (I2);
		PRINTINT (I3);
		WRITE (OUTPUT, '  ');
		PRINTSTRING (SVAL, SLGTH);
		end;

	 UXJP :
		begin
		PRINTTYP (TYP);
		PRINTNAM (NAM1);
		PRINTNAM (NAM2);
		PRINTINT (I1);
		PRINTINT (I2);
		end;

	ULOD, UNSTR, UPAR, UPLOD, USTR, UPSTR :
		begin
		PRINTTYP (TYP);
		PRINTMTYP (MTYP);
		PRINTINT (I1);
		PRINTINT (I2);
		PRINTINT (I3);
		end;

	UCSP :	begin
		PRINTTYP (TYP);
		PRINTNAM (NAM1);
		PRINTINT (I1);
		PRINTINT (I2);
		end;

	UCUP :	begin
		PRINTTYP (TYP);
		PRINTINT (I1);
		PRINTNAM (NAM1);
		PRINTINT (I2);
		PRINTINT (I3);
		end;

	ULDC :	begin
		PRINTTYP (TYP);
		PRINTINT (I1);
		case TYP of
		    TYPUI, TYPUK, TYPUM, TYPUQ :
			     ERROR(WNOT_IMPLEMENTED);
		    TYPUB, TYPUJ, TYPUL :
			     PRINTINT (I2);
		    TYPUC :  PRINTSCONST (SVAL, SLGTH);
		    TYPUR :  WRITE (OUTPUT, '  ', R1);
		    TYPUN :  (*null case*);
		    TYPUS :  PRINTSET (P1);
		    end (*case TYP of*);
		end (*ULDC*);

	ULCA :	begin
		PRINTTYP (TYP);
		PRINTINT (I1);
		case TYP of
		    TYPUI, TYPUK, TYPUQ :
			     ERROR(WNOT_IMPLEMENTED);
		    TYPUB, TYPUJ, TYPUL :
			     PRINTINT (I2);
		    TYPUC :  PRINTSCONST (SVAL, SLGTH);
		    TYPUR :  WRITE (OUTPUT, '  ', R1);
		    TYPUS :  PRINTSET (P1);
		    TYPUM :  PRINTSCONST (SVAL, SLGTH);
		    end (*case TYP of*);
		end (*ULCA*);

	UCOMM :
		begin
		WRITE (OUTPUT,' ');
		for I := 1 to CLEN do
		    WRITE(OUTPUT, COMMFIELD[I]);
		WRITELN(OUTPUT);
		end ;
		

	UUNK :	begin
		PRINTINT (I2);
		PRINTINT (I3);
		WRITE (OUTPUT,' ');
		PRINTSTRING (SVAL, SLGTH);
		end;

    end (*case OPC of*);

    WRITELN(OUTPUT);

    end (*PRINTNXTINST*);

(** SETREP_PROCESSOR_CLASS:	SET_IN SET_DIF SET_INT SET_UNI BUILD_SET *)(*setch*)
(**)

(*%IFF SET4*)

function SET_IN(*(SET_EL :  SET_EL_TYP; PSET :  SETREP) :  boolean*);
(* SET_IN performs the function of the set IN operator for the structured
   representation of large sets.  Its first parameter is the scalar to be
   tested for inclusion in the set, which is the second parameter. setch*)

    var INDEX :  SETREP_INDEX;

    begin
    INDEX  := SET_EL div HOST_SET_SIZE;	(*figure which real set to use*)
    SET_EL := SET_EL mod HOST_SET_SIZE; (*figure correct offset*)
    if SET_EL in PSET[INDEX] then
        SET_IN := true
    else
        SET_IN := false;
    end (*SET_IN*);


(* SET_DIF, SET_INT, and SET_UNI perform the functions of set difference,
   intersection, and union, respectively, for the structured representation
   of large sets.  Note that their parameters A, B, and C correspond to the
   construct  A := B <setop> C . 				    setch*)


procedure SET_DIF(var DESTSET :  SETREP; OP1SET, OP2SET :  SETREP);  (*setch*)
    var	I :  SETREP_INDEX;
    begin
    for I := 0 to SETREP_MAX do
	DESTSET[I] := OP1SET[I] - OP2SET[I];
    end (*SET_DIF*);


procedure SET_INT(var DESTSET :  SETREP; OP1SET, OP2SET :  SETREP);  (*setch*)
    var	I :  SETREP_INDEX;
    begin
    for I := 0 to SETREP_MAX do
	DESTSET[I] := OP1SET[I] * OP2SET[I];
    end (*SET_INT*);


procedure SET_UNI(var DESTSET :  SETREP; OP1SET, OP2SET :  SETREP);  (*setch*)
    var	I :  SETREP_INDEX;
    begin
    for I := 0 to SETREP_MAX do
	DESTSET[I] := OP1SET[I] + OP2SET[I];
    end (*SET_UNI*);


procedure BUILD_SET(var S :  SETREP; SET_EL :  SET_EL_TYP);
    (*Add a scalar to a structured representation of a large set.*)  (*setch*)

    var INDEX: SETREP_INDEX;

    begin
    INDEX := SET_EL div HOST_SET_SIZE;
    SET_EL := SET_EL mod HOST_SET_SIZE;
    S[INDEX] := S[INDEX]+[SET_EL];
    end (*BUILD_SET*);

(*%ELSE*)
%\
%function SET_IN(*(SET_EL :  SET_EL_TYP; PSET :  SETREP) :  boolean*);(*setch*)\
%    begin\
%    SET_IN := SET_EL in PSET\
%    end (*SET_IN*);\
%\
%\
%procedure SET_DIF(var DESTSET :  SETREP; OP1SET, OP2SET :  SETREP);  (*setch*)\
%    begin\
%    DESTSET := OP1SET - OP2SET\
%    end (*SET_DIF*);\
%\
%\
%procedure SET_INT(var DESTSET :  SETREP; OP1SET, OP2SET :  SETREP);  (*setch*)\
%    begin\
%    DESTSET := OP1SET * OP2SET\
%    end (*SET_INT*);\
%\
%\
%procedure SET_UNI(var DESTSET :  SETREP; OP1SET, OP2SET :  SETREP);  (*setch*)\
%    begin\
%    DESTSET := OP1SET + OP2SET\
%    end (*SET_UNI*);\
%\
%\
%procedure BUILD_SET(var S :  SETREP; SET_EL :  SET_EL_TYP);	(*setch*)\
%    begin\
%    S := S + [SET_EL]\
%    end (*BUILD_SET*);\
%\
(*%ENDC*)
(** S1WORD_PROCESSOR_CLASS:		NEWCODEREC MAKE_NEWINSTREC NEWOPNDXWORDREC NEWOPND2REC GETFIELD GETSIGNEDFIELD PUTFIELD **)
(**)

procedure NEWCODEREC(var X :  A_CODEREC);
    (*Gets a fresh new CODEREC from the heap.*)

    begin
    new(X);
    X↑.NEXTPTR := nil;
    X↑.CODEWORD := ZEROS1WORD
    end (*NEWCODEREC*);


procedure MAKE_NEWINSTREC(var X : AN_INSTREC);			(*DATASTRCH*)
   (*Gets a fresh new INSTREC from the heap. *)
    begin
    new(X);
    with X↑ do
	begin
	NEXTPTR := nil;
	PREVPTR := nil;
	IWDS := 0;
	with INSTOPND1 do
	    begin
	    REG := 0;
	    F := 0;
	    XWD := nil;
	    end(*INSTOPND1*);
	with INSTOPND2 do
	    begin
	    REG := 0;
	    F := 0;
	    XWD := nil;
	    end(*INSTOPND2*);
	end(*X↑*);
    end(*MAKE_NEWINSTREC*);


procedure NEWOPNDXWORDREC(var X : AN_OPNDXWORDREC);		(*DATASTRCH*)
    (*Gets a fresh new OPNDXWORDREC from heap.*)
    begin
    new(X);
    X↑.NEXTPTR := nil;
    X↑.XWORDPTR := nil
    end (*NEWOPNDXWORDREC*);


procedure NEWOPND2REC(var X : AN_OPND2REC);			(*DATASTRCH*)
    (*Gets a fresh new OPND2REC from heap.*)
    begin
    new(X);
    X↑.NEXTPTR := nil;
    X↑.OPND2IPTR := nil
    end (*NEWOPND2REC*);



function GETFIELD (var WORD :  S1WORD;	STARTBIT :  S1BITNUM;
			      BITLEN :	BITFIELD_LENGTH) :  integer;
    (*Returns in the low-order BITLEN bits of the result the unsigned
	value of the field of WORD starting at bit number STARTBIT.
	For the present, BITLEN must be <= BITS_ON_COMP_MACH - 1.
	Bits are numbered from left to right starting at 0.
	Note : this routine changes when S1WORDs really exist!*)

(*%IFT D10*)					(*4AUG79 PTZ...*)
    extern;    
(*%ELSE*)
%   external;  \
(*%ENDC*)					(*...4AUG79 PTZ*)
%************insert assembly versions*************)
    var W1, W2 :  integer;
	FIRSTAFTER :  integer;

    begin
    W1 := WORD.LHALF;
    W2 := WORD.RHALF;
    FIRSTAFTER := STARTBIT + BITLEN;
    if not ((BITLEN <= BITS_ON_COMP_MACH - 1) and
	    (0<=W1) and (W1<TWOEXP[18]) and
	    (0<=W2) and (W2<TWOEXP[18])) then ASSERTFAIL('GETFIELD 001');

    if STARTBIT <= 17 then

	if FIRSTAFTER > 18 then
	    (*crosses the 'halfword' boundary*)
	    GETFIELD:=
		    W1 mod TWOEXP[18-STARTBIT] * TWOEXP[FIRSTAFTER-18]
		    + W2 div TWOEXP[36-FIRSTAFTER]

	else
	    (*totally in left halfword*)
	    GETFIELD := (W1 mod TWOEXP[18-STARTBIT])
			 div TWOEXP[18-FIRSTAFTER]

    else
	(*totally in right halfword*)
	GETFIELD := (W2 mod TWOEXP[36-STARTBIT])
		     div TWOEXP[36-FIRSTAFTER];

    end (*GETFIELD*);
(*****************end of comment out***************\


function GETSIGNEDFIELD (var WORD :  S1WORD;
			  STARTBIT :  S1BITNUM;
			  BITLEN :  BITFIELD_LENGTH) :	integer;
    (*Do sign-extend on GETFIELD.  BITLEN must be <= BITS_ON_COMP_MACH - 1.*)

(*%IFT D10*)					(*4AUG79 PTZ...*)
    extern;    
(*%ELSE*)
%   external;   \
(*%ENDC*)					(*...4AUG79 PTZ*)
%***********insert assembly versions**************)
    var T :  integer;

    begin
    if not ( BITLEN <= BITS_ON_COMP_MACH - 1) then ASSERTFAIL('GETSIGNED001');
    T := GETFIELD (WORD, STARTBIT, BITLEN);
    if (T>=TWOEXP[BITLEN-1]) and (BITLEN<WORDBITS) then
	if BITLEN <= MAX_EXP_ON_COMP_MACH then
	    GETSIGNEDFIELD := T - TWOEXP[BITLEN]
	else
	    begin
	    T := T - TWOEXP[MAX_EXP_ON_COMP_MACH];
	    GETSIGNEDFIELD := T - TWOEXP[MAX_EXP_ON_COMP_MACH];
	    end
    else
	GETSIGNEDFIELD := T;
    end (*GETSIGNEDFIELD*);
(*****************end of comment out***************\



procedure PUTFIELD (var WORD :	S1WORD;  STARTBIT :  S1BITNUM;
		    BITLEN :  BITFIELD_LENGTH;	FIELDVAL :  integer);
    (*Copies the low order BITLEN bits from FIELDVAL into a field
	in WORD starting at bit number STARTBIT.  (Bits are numbered
	from left to right starting at 0.) High-order bits in FIELDVAL
	should be either all ones or all zeros.  Note : this routine
	changes when S1WORDs really exist!  At present assumes that
	BITLEN <= BITS_ON_COMP_MACH - 1.*)

(*%IFT D10*)					(*4AUG79 PTZ...*)
    extern;  
(*%ELSE*)
%   external;   \
(*%ENDC*)					(*...4AUG79 PTZ*)
%***********insert assembly versions*************)
    var W1, W2 :  integer;
	P :  integer;
	FIRSTAFTER :  integer;

    begin
    if not (BITLEN <= BITS_ON_COMP_MACH - 1) then ASSERTFAIL('PUTFIELD 001');
    W1 := WORD.LHALF;
    W2 := WORD.RHALF;
    FIRSTAFTER := STARTBIT + BITLEN;
    if not ((0<=W1) and (W1<TWOEXP[18]) and
	    (0<=W2) and (W2<TWOEXP[18])) then ASSERTFAIL('PUTFIELD 002');

    (*Zero out sign-extend bits of FIELDVAL.*)
    if FIELDVAL < 0 then
	if BITLEN <= MAX_EXP_ON_COMP_MACH then
	    FIELDVAL := FIELDVAL + TWOEXP[BITLEN]
	else
	    begin
	    FIELDVAL := FIELDVAL + TWOEXP[MAX_EXP_ON_COMP_MACH];
	    FIELDVAL := FIELDVAL + TWOEXP[MAX_EXP_ON_COMP_MACH];
	    end;
    if not (0<=FIELDVAL) then ASSERTFAIL('PUTFIELD 003');
    if BITLEN <= MAX_EXP_ON_COMP_MACH then
	if not (FIELDVAL < TWOEXP[BITLEN]) then ASSERTFAIL('PUTFIELD 004');

    if STARTBIT <= 17 then

	if FIRSTAFTER > 18 then

	    begin  (*crosses 'halfword' boundary*)
	    W1	:=  W1	-  W1 mod TWOEXP[18-STARTBIT]
		       + FIELDVAL div TWOEXP[FIRSTAFTER-18];
	    W2	:=  W2 mod TWOEXP[36-FIRSTAFTER]
		     + FIELDVAL mod TWOEXP[FIRSTAFTER-18]
				  * TWOEXP[36-FIRSTAFTER];
	    end

	else
	    (*entirely in left half*)
	    W1	:=  W1	-  W1 mod TWOEXP[18-STARTBIT]
		       +  W1 mod TWOEXP[18-FIRSTAFTER]
		       +  FIELDVAL * TWOEXP[18-FIRSTAFTER]

    else
	(*entirely in right half*)
	W2  :=	W2  -  W2 mod TWOEXP[36-STARTBIT]
		   +  W2 mod TWOEXP[36-FIRSTAFTER]
		   +  FIELDVAL * TWOEXP[36-FIRSTAFTER];

    WORD.LHALF := W1;
    WORD.RHALF := W2;

    end (*PUTFIELD*);
(*****************end of comment out***************\
(** S1WORD_PROCESSOR_CLASS:	REAL_TO_S1WORD ZSYMBOL_TO_S1WORDS INTEGER_TO_S1WORD SETREP_TO_S1WORDS **)
(**)

(* Comment out the 370 version...
   Note that this procedure will not work until PASCAL supports
   the type xreal.

procedure XREAL_TO_S1WORDS(var W1, W2 :	S1WORD; XRVAL :	xreal);
    "*Translate an extended real value into a pair of S1 words.
     WARNING: This routine is totally 370 PASCAL dependent;
	      It will be much simpler in its S-1 version.*"

    type TRIT = 0..2;

    var NEG :  boolean;
	EXP :  integer;
	TOP27, BOT29 :	integer;
	ICR :  record
	       DUMMY :	integer  "*alignment*";
	       case TAG:TRIT of
		    0: (I: array [1..2] of integer);
		    1: (C: packed array [1..8] of char);
		    2: (R: real)
	       end;

    begin
    W1 := ZEROS1WORD;  W2 := ZEROS1WORD;
    ICR.R := XRVAL;
    if ICR.R <> 0.0 then
	begin
	if ICR.R >= 0.0 then NEG := false else
	    begin ICR.R := -ICR.R; NEG := true end;
	EXP := (ord(ICR.C[1]) - 64) * 4;
	ICR.C[1] := chr(0);
	TOP27 := ICR.I[1]*8  +	ord(ICR.C[5]) div 32;
	ICR.C[5] := chr(ord(ICR.C[5]) mod 32);
	BOT29 := ICR.I[2];
	while TOP27 < TWOEXP[26] do  "*binary normalize*"
	    begin
	    EXP := EXP - 1;
	    BOT29 := BOT29 * 2;
	    TOP27 := TOP27 * 2;
	    if BOT29 >= TWOEXP[29] then
		begin
		BOT29 := BOT29 - TWOEXP[29];
		TOP27 := TOP27 + 1
		end
	    end;

	EXP := EXP + 128;  "*to excess 128*"

	if NEG then  "*want twos complement*"
	    begin
	    BOT29 := - BOT29;
	    if BOT29<>0 then TOP27 := TOP27 + 1;
	    TOP27 := - TOP27;
	    if (BOT29<>0) or (TOP27<>0) then EXP := EXP + 1;
	    EXP := - EXP
	    end;

	PUTFIELD(W1,0,9,EXP);
	PUTFIELD(W1,9,27,TOP27);
	PUTFIELD(W2,0,29,BOT29)

	end "*ICR <> 0.0*"

    end "*XREAL_TO_S1WORDS*";
...*)


(* The following procedure will not work until PASCAL supports
   the type xreal.

procedure XREAL_TO_S1WORDS(var W1, W2 :	S1WORD; XRVAL :	xreal);
    "*Translate an extended real value into a pair of S1 words.
      S-1 VERSION and PDP-10 VERSION (same procedure) *"

    var RS10 : record	  "*for getting (only) word on PDP-10*"
	       case BIT of
		    0:  (R: real; I: integer);
		    1:  (S: HOST_SET_TYP)	"*setch*"
	       end;
	RSH : record	  "*for getting high order word on S-1*"
	      case BIT of
		   0:  (I: integer; R: real);
		   1:  (S: HOST_SET_TYP; J: integer)	"*setch*"
	      end;
	RSL : record	  "*for getting low order word on S-1*"
	      case BIT of
		   0:  (R: real);
		   1:  (S: HOST_SET_TYP)	"*setch*"
	      end;
	N :  HOST_SET_EL_TYP;			"*setch*"

    begin
    RS10.R := 0.0;
    RS10.I := -1;
    if 36 in RS10.S then
	begin "*PDP-10*"
	RS10.R := XRVAL;
	RS10.I := 0;
	W1 := ZEROS1WORD;
	for N := 0 to WORDBITS-1 do
	    if N in RS10.S then
		PUTFIELD (W1, N, 1, 1);
	W2 := ZEROS1WORD;
	end "*PDP-10*"
    else
	begin "*S-1*"
	RSH.I := 0;
	RSH.R := XRVAL;
	W1 := ZEROS1WORD;
	for N := WORDBITS-1 downto 0 do
	    if N in RSH.S then
		PUTFIELD (W1, WORDBITS-1-N, 1, 1);
	RSL.R := XRVAL;
	W2 := ZEROS1WORD;
	for N := WORDBITS-1 downto 0 do
	    if N in RSL.S then
		PUTFIELD (W2, WORDBITS-1-N, 1, 1);
	end "*S-1*";
    end "*XREAL_TO_S1WORDS*";
...*)

(*procedure S1WORD_TO_REAL(var W : S1WORD; RVAL : real);*) 	(*23dec78 ALS*)
    (*Translates one S1WORD into a real value.*)

procedure REAL_TO_S1WORD(var W :  S1WORD; RVAL :  real);	(*LCW*)
    (*Translate a real value into one S1 word.
      S-1 VERSION and PDP-10 VERSION (same procedure).
      This procedure assumes that the representation of a single-word real
      is the same on the host compiler and the S-1 (true for the PDP-10 and
      the S-1 Mark I).
      A note about variant records and sets on various machines:
			   wd 1     wd 2   wd 3     wd 4
	S-1 4 word set =  143-108, 107-72, 71-36,   35-0
	S-1 2 word set =   71-36,   35-0
	PDP-10 4 word set = 0-35,   36-71, 72-107, 108-143 (does not exist yet)
	PDP-10 2 word set = 0-35,   36-71
      The idea is to store the real number being translated in the first
      word of the set and then find the right bit numbers in the appropriate
      set representation to get it back out. *)

    var RS :  record	  				(*16AUG79 PTZ*)
	       case BIT of
		    0:  (R1: real;
			 I2: integer;  (*don't declare in a list because*)
			 I3: integer;  (*the last item in the list might*)
			 I4: integer); (*get allocated first*)
(*%IFT D10*)						(*setch*) (*29AUG79 PTZ*)
		    1:  (S: set of 0..36) 
(*%ELSE*)
%		    1:  (S: set of 0..SET_MAX)\
(*%ENDC*)
	       end;

	N :  0..SET_MAX;				(*setch*) (*29AUG79 PTZ*)

    begin
    RS.R1 := 0.0;
    RS.I2 := -1;
    RS.I3 := 0;
    RS.I4 := 0;
    if 36 in RS.S then
	begin (*PDP-10*)
	RS.R1 := RVAL;
	RS.I2 := 0;
	W := ZEROS1WORD;
	for N := 0 to WORDBITS-1 do
	    if N in RS.S then
		PUTFIELD (W, N, 1, 1);
	end (*PDP-10*)
    else
	begin (*S-1*)					(*16AUG79 PTZ...*)
	RS.R1 := RVAL;
	RS.I2 := 0;
	W := ZEROS1WORD;
	for N := SET_MAX downto SET_MAX - WORDBITS do
	    if N in RS.S then
		PUTFIELD (W, SET_MAX-N, 1, 1);
	end (*S-1*);					(*...16AUG79 PTZ*)
    end (*REAL_TO_S1WORD*);



procedure ZSYMBOL_TO_S1WORDS(var W1, W2 :  S1WORD; LSNAM :  ALFA);
    (*Translate a symbol name into a pair of S1 words.*)

    var I, STBIT :  integer;
	SNAM :  ZSYMBOL;

    begin
    for I := 1 to 8 do              (*als/peg 25jul79*)
	SNAM[I] := LSNAM[I];        (*als/peg 25jul79*)
    W1 := ZEROS1WORD;
    W2 := ZEROS1WORD;
    STBIT := 0;
    for I := 1 to WORDCHARS do
	begin
        PUTFIELD(W1,STBIT,CHARBITS,ord(SNAM[I])-CHARDIF);           (*CHARDIF*)
	STBIT := STBIT + CHARBITS
	end;
    STBIT := 0;
    for I := 1 to WORDCHARS do
	begin
	PUTFIELD(W2,STBIT,CHARBITS,ord(SNAM[WORDCHARS+I])-CHARDIF); (*CHARDIF*)
	STBIT := STBIT + CHARBITS
	end
    end (*ZSYMBOL_TO_S1WORDS*);


procedure INTEGER_TO_S1WORD (var W :  S1WORD;  I : integer);
    (*Put the integer I into the S1WORD, sign-extended.*)

    begin
    W := ZEROS1WORD;
    PUTFIELD (W, WORDBITS-(BITS_ON_COMP_MACH-1), BITS_ON_COMP_MACH-1, I);
    if I < 0 then
	PUTFIELD (W, 0, WORDBITS-(BITS_ON_COMP_MACH-1), -1);
    end (*INTEGER_TO_S1WORD*);



procedure SETREP_TO_S1WORDS (var S1SET :  S1SETREP;  SVAL :  SETREP);
    (*Translate a set value to the S1's set representation.
         Note that SET_MAX = S1SETREP_SIZE*WORDBITS - 1.*)
    (*Would it be faster to equivalence a set to integers?*)

    var	INDEX :  S1SETREP_INDEX;			(*setch...*)
	N, TMP1, TMP2 :  SET_EL_TYP;

    begin
    for INDEX := 0 to S1SETREP_MAX do
	begin
	S1SET[INDEX] := ZEROS1WORD;
	TMP1 := (S1SETREP_MAX + 1 - INDEX)*WORDBITS - 1;
	TMP2 := (S1SETREP_MAX - INDEX)*WORDBITS;
	for N := TMP1 downto TMP2 do
	    if SET_IN(N, SVAL) then
		PUTFIELD(S1SET[INDEX], TMP1 - N, 1, 1);
	end;						(*...setch*)

    end (*SETREP_TO_S1WORDS*);
(** MISCELLANEOUS_CLASS:	LABELHASH LABELNUMBER MIN MAX POWER2 FLDW CVCHR_S1WORD_4 CVOS_S1WORD_12 CVOS_12 CVOS_10 CSP_HASH OPC_HASH NAME_TO_CSP MNEM_TO_OPC **)
(**)

function LABELHASH (LNUM :  LBL_INDEX) :  RNG_0_LBLHTSIZEM1;
    begin
    LABELHASH := ABS(LNUM) mod LBLHTSIZE;
    end (*LABELHASH*);



function LABELNUMBER (var NAME :  NAMEREC) :  LBL_INDEX;
    (*Converts a label name into a label number.*)

    var I :  ALFALEN;
	NUM :  0..MAXLBL;

    begin
    I := 2;   (*Skip the initial 'L'.*)
    NUM := 0;
    while (I<ALFASIZE) and (NAME.NAM[I]<>' ') do
	begin
	NUM := NUM*10 + ord(NAME.NAM[I]) - ord('0');
	I := I + 1;
	end;
    if NAME.NAM[I] = ' ' then LABELNUMBER := NUM
    else LABELNUMBER := NUM*10 + ord(NAME.NAM[I]) - ord('0');
    end (*LABELNUMBER*);



function MIN (X, Y :  integer) :  integer;
    begin
    if X < Y then MIN := X else MIN := Y;
    end (*MIN*);



function MAX (X, Y :  integer) :  integer;
    begin
    if X > Y then MAX := X else MAX := Y;
    end (*MAX*);



function POWER2 (X :  integer) :  integer;
    (*Return the integer k such that 2**k = X if X is a power of 2.
	Otherwise return some k < 0.*)

    var COUNT :  integer;

    begin
    if X <= 0 then POWER2 := -999
    else if X = 1 then POWER2 := 0
    else if ODD(X) then POWER2 := -999
    else if X = 2 then POWER2 := 1
    else if X = 4 then POWER2 := 2
    else if X = 8 then POWER2 := 3
    else if X = 16 then POWER2 := 4
    else if X = 32 then POWER2 := 5
    else
	begin
	COUNT := 0;
	repeat
	    COUNT := COUNT + 1;
	    X := X div 2;
	until ODD(X) or (X <= 32);
	if X = 32 then POWER2 := COUNT + 5
	else POWER2 := -999;
	end;
    end (*POWER2*);


function FLDW(*(NUM :  integer) :  integer*);
    (*Returns the field width required to exactly contain (with no
     spaces) the value NUM represented in decimal.*)

    var FW :  integer;

    begin
    FW := 0;
    if NUM < 0 then
	begin
	FW := 1;
	NUM := abs(NUM)
	end;
    repeat
	NUM := NUM div 10;
	FW := FW + 1
    until NUM = 0;
    FLDW := FW
    end (*FLDW*);

procedure CVCHR_S1WORD_4(var ANS :  CHAR4;  W :  S1WORD);    (*23DEC78 ALS...*)
    (*Converts an S1WORD into a string of 4 characters.*)

    var I : 1..4;

    begin
    for I := 1 to 4 do
	ANS[I] := chr(GETFIELD(W, 9*(I - 1), 9) + CHARDIF);(*CHARDIF*)
    end(*CVCHR_S1WORD_4*);				 (*...23DEC78 ALS*)


procedure CVOS_S1WORD_12(var ANS :  CHAR12;  W :  S1WORD);
(*Converts an S1WORD into an octal string of 12 characters.*)

var I :  1..12;

begin
for I := 1 to 12 do
    ANS[I] := chr(ord('0') + GETFIELD(W,3*(I-1),3));
I := 1;
while (I < 12) and (ANS[I] = '0') do
    begin
    ANS[I] := ' ';
    I := I + 1
    end
end (*CVOS_S1WORD_12*);


procedure CVOS_12(var ANS :  CHAR12;  K : NONNEGINT);
(*Converts a non-negative integer into an octal string of 12 chars.*)

var I :  1..12;

begin
ANS := '           0';
I := 12;
while K > 0 do
    begin
    ANS[I] := chr(ord('0') + (K mod 8));
    K := K div 8;
    I := I - 1
    end
end (*CVOS_12*);


procedure CVOS_10(var ANS :  CHAR10;  K : NONNEGINT);
(*Converts a non-negative integer into an octal string of 10 chars.*)

var I :  1..10;

begin
ANS := '         0';
I := 10;
while K > 0 do
    begin
    if not (I>0) then ASSERTFAIL('CVOS_10  001');
    ANS[I] := chr(ord('0') + (K mod 8));
    K := K div 8;
    I := I - 1
    end
end (*CVOS_10*);



(* als should fix this if it becomes a problem...*)

function CSP_HASH (var NAM :  ALFA) :  integer;
    begin
    CSP_HASH := (ord(NAM[1])*676 + ord(NAM[2])*26 + ord(NAM[3]))
		mod CSPHTSIZE;
    end (*CSP_HASH*);	(*...als fix*)



function OPC_HASH (var MNEM :  CHAR4) :  integer;
    begin
    OPC_HASH := (((ord(MNEM[2])*4 + ord(MNEM[1]))*8 + ord(MNEM[3]))*8
		 +ord(MNEM[4])*8) mod OPCHTSIZE; 
(*  OPC_HASH := (ord(MNEM[1])*676 + ord(MNEM[2])*26 + ord(MNEM[3]))
		mod OPCHTSIZE;			als 16jul79 *)
    end (*OPC_HASH*);



function NAME_TO_CSP (var NAME :  NAMEREC) :  P_STANDARDPROC;
    (*Look up the name in a hash table.*)

    var H :  integer;

    begin
    H := CSP_HASH (NAME.NAM);
    while (CSPHASHTAB[H].CSPNAM <> NAME) and
	  (CSPHASHTAB[H].CSPNAM.NAM <> '                ') do
	H := (H + 1) mod CSPHTSIZE;
    if CSPHASHTAB[H].CSPNAM = NAME then
	NAME_TO_CSP := CSPHASHTAB[H].CSP
    else ERROR (WINVAL_CSP);
    end (*NAME_TO_CSP*);




function MNEM_TO_OPC (var MNEM :  CHAR4) :  U_OPCODE;
    (*Look up the mnemonic in a hash table.*)

    var H :  integer;

    begin
    H := OPC_HASH (MNEM);
    while (OPCHASHTAB[H].OPCNAM <> MNEM) and
	  (OPCHASHTAB[H].OPCNAM <> '    ') do
	H := (H + 1) mod OPCHTSIZE;
    if OPCHASHTAB[H].OPCNAM = MNEM then
	MNEM_TO_OPC := OPCHASHTAB[H].OPC
    else ERROR (WINVAL_OPC);
   end (*MNEM_TO_OPC*);





(** INSTRUCTION_PROCESSOR_CLASS:	S1OPNDS_EQUAL S1OPND_TEMPLOC AFTER_FAKEOPS AFTER_NONS1LOC_FAKEOPS INVERT_OPCODE **)
(**)

function S1OPNDS_EQUAL (INST1LOC : AN_INSTREC;  INST1OPNDNUM : OPNDNUM;(*PTZ*)
			INST2LOC : AN_INSTREC;
			INST2OPNDNUM : OPNDNUM) : boolean;	(*DATASTRCH*)
    (*Return true iff the 2 operands (including extended words) are equal,
      assuming that the instructions are real S1 instructions, and also
      that we're NOT comparing jump or skip destinations.
      This routine does not consider different ways of referring to the same
      location as being equal - operands must be IDENTICAL to match.
      This routine is not passed INSTOPNDs so as to not sacrifice the 
      checking of VJOP and INSTOPND2*)

    var INST1OPND, INST2OPND : INSTOPND;

    begin
    if not (not ((INST1LOC↑.OPFMT = VJOP) and (INST1OPNDNUM = OPND2NUM))
	    and not ((INST2LOC↑.OPFMT = VJOP) and (INST2OPNDNUM = OPND2NUM))) then
        ASSERTFAIL('S1OPNDS_E001');
    if INST1OPNDNUM = OPND1NUM then  
	INST1OPND := INST1LOC↑.INSTOPND1
    else  
	INST1OPND := INST1LOC↑.INSTOPND2;
    if INST2OPNDNUM = OPND1NUM then  
	INST2OPND := INST2LOC↑.INSTOPND1
    else  
	INST2OPND := INST2LOC↑.INSTOPND2;
    if (INST1OPND.REG = INST2OPND.REG) and (INST1OPND.F = INST2OPND.F) then
	begin
	if (INST1OPND.XWD = nil) or (INST2OPND.XWD = nil) then
	    S1OPNDS_EQUAL := INST1OPND.XWD = INST2OPND.XWD
	else
	    S1OPNDS_EQUAL := INST1OPND.XWD↑ = INST2OPND.XWD↑
	    (*for this to work, the entire OPERAND_XWD block must be filled in
	      in a consistent way, including tag field.  Any space unused by
	      a given variant should be zeroed*)
	end
    else
	S1OPNDS_EQUAL := false
    end (*S1OPNDS_EQUAL*);


function S1OPND_TEMPLOC (OPND : INSTOPND) : integer;	(*PTZ*)	(*DATASTRCH*)
    (*Return value >= 0 iff the OPND starting at SHORTSTARTBIT
      of the instruction at INSTLOC is a temporary location.
      Currently checks only for temp register or
      RTA, RTB & returns the register number if the OPND is a
      temporary location. Should be changed when temporaries
      are allowed to spill onto the stack or elsewhere*)

    begin
    if (OPND.XWD = nil) and (OPND.REG = 0)
     and (((S1RTA <= OPND.F) and (OPND.F <= succ(S1RTB)))
     or ((MINTMPS1REG <= OPND.F) and (OPND.F <= MAXTMPS1REG))) then
	S1OPND_TEMPLOC := OPND.F
    else
	S1OPND_TEMPLOC := -1
    end (*S1OPND_TEMPLOC*);


function AFTER_FAKEOPS(INSTLOC :  AN_INSTREC) :	AN_INSTREC;	(*DATASTRCH*)
    (*Return pointer to first non-FAKEOP instruction
     starting at INSTLOC or beyond.*)
    var LOOKING :  boolean;

    begin
    LOOKING := true;
    while LOOKING do
	if INSTLOC = nil then LOOKING := false
	else
	    if INSTLOC↑.OPFMT = VFAKEOP
		then INSTLOC := INSTLOC↑.NEXTPTR
		else LOOKING := false;
    AFTER_FAKEOPS := INSTLOC
    end (*AFTER_FAKEOPS*);


function AFTER_NONS1LOC_FAKEOPS(INSTLOC :  AN_INSTREC) : AN_INSTREC; (*7MAR79 PTZ*)
    (*Return pointer to either the first real instruction or the first
      S1LOC instruction at INSTLOC or beyond*)			(*DATASTRCH*)

    var LOOKING :  boolean;

    begin
    LOOKING := true;
    while LOOKING do
	if INSTLOC = nil then LOOKING := false
	else
	    if (INSTLOC↑.OPCODE = XS1LOC) or (INSTLOC↑.OPFMT <> VFAKEOP) then
		LOOKING := false
	    else
		INSTLOC := INSTLOC↑.NEXTPTR;
    AFTER_NONS1LOC_FAKEOPS := INSTLOC
    end (*AFTER_NONS1LOC_FAKEOPS*);


procedure INVERT_OPCODE (INSTLOC :  AN_INSTREC); (*7MAR79 PTZ*)	(*DATASTRCH*)
    (*Change the instruction at INSTLOC to have the reverse opcode,
    i.e. the one so that OP X,Y = REVERSE_OP Y,X*)

    var S1OPC :  S1OPCODE;

    begin
    S1OPC := REVERSE_OP[INSTLOC↑.OPCODE];
    if not (S1OPC <> XILLEGAL) then
	ASSERTFAIL('INVERT_OP001');
    INSTLOC↑.OPCODE := S1OPC
    end (*INVERT_OPCODE*);
(** INSTRUCTION_PROCESSOR_CLASS:	DELETE_INSTR INSERT_OPND1 PEEP_LOC_IS_FREE SWAP_OPERANDS INSTR_WORDS PRINTMAINCODE **)
(**)

procedure DELETE_INSTR (DELPTR : AN_INSTREC);	(*7MAR79 PTZ*)	(*DATASTRCH*)
    (* Deletes the MAINCODE instruction whose 1st CODEREC is pointed to by DELPTR.*)

    begin
    with DELPTR↑ do
	begin
	if NEXTPTR <> nil then					(*29AUG79 PTZ*)
	    NEXTPTR↑.PREVPTR := PREVPTR
	else
	    begin
	    if not (MAINCODE.LAST = DELPTR) then
		ASSERTFAIL('DELETE_IN001');
	    MAINCODE.LAST := PREVPTR;
	    end;
	if PREVPTR <> nil then					(*29AUG79 PTZ*)
	    PREVPTR↑.NEXTPTR := NEXTPTR
	else
	    begin
	    if not (MAINCODE.FIRST = DELPTR) then
		ASSERTFAIL('DELETE_IN002');
	    MAINCODE.FIRST := NEXTPTR;
	    end;
	MAINCODE.NWORDS := MAINCODE.NWORDS - IWDS
	end;
    end (*DELETE_INSTR*);
	      
 
procedure INSERT_OPND1 (INSTPTR : AN_INSTREC;  OPND1 : INSTOPND);     (*PTZ*)
								(*DATASTRCH*)
    var TWDS : integer;

    begin
    TWDS := 0;
    with INSTPTR↑ do
	begin
	if INSTOPND1.XWD <> nil then
	    TWDS := TWDS + 1;
	if OPND1.XWD <> nil then
	    TWDS := TWDS - 1;
	INSTOPND1 := OPND1;
	IWDS := IWDS - TWDS;
	end;
    MAINCODE.NWORDS := MAINCODE.NWORDS - TWDS
    end (*INSERT_OPND1*);


function PEEP_LOC_IS_FREE (INSTLOC : AN_INSTREC;		(*DATASTRCH*)
			   TMPLOC : integer) : boolean;		(*7MAR79 PTZ*)
    (*returns true iff the value contained in the location
    given by TMPLOC is dead at INSTLOC, i.e. will not be used again.
    This currently only applies to temp registers, but could also
    apply to register spill locations (when they are implemented)
    or other places, if FREEREGs are emitted to track such locations*)

    var FOUND, STILL_LOOKING :  boolean;

    begin
    FOUND := false;
    STILL_LOOKING := INSTLOC <> nil;
    while STILL_LOOKING and not FOUND do
	begin
	if INSTLOC↑.OPFMT <> VFAKEOP then
	    (* it's okay to cross S1LOC fakeinstrs here, because
	       they really belong to the next instr*)
	    STILL_LOOKING := false
	else
	    begin (* VFAKEOP *)
	    if INSTLOC↑.OPCODE = XFREEREG then
		begin
		if INSTLOC↑.FAKEOPND = TMPLOC then
		    FOUND := true
		end;
	    INSTLOC := INSTLOC↑.NEXTPTR;
	    STILL_LOOKING := INSTLOC <> nil
	    end (* VFAKEOP *)
	end (*while*);
    PEEP_LOC_IS_FREE := FOUND
    end (*PEEP_LOC_IS_FREE*);



procedure SWAP_OPERANDS (INSTLOC : AN_INSTREC);	(*7MAR79 PTZ*)	(*DATASTRCH*)
    (*Swaps the 2 operands of the instruction at INSTLOC*)

    var TMPOPND1 : INSTOPND;

    begin
    with INSTLOC↑ do
	begin
	if not (OPFMT <> VJOP) then
	    ASSERTFAIL('SWAP_OPER001');
	TMPOPND1 := INSTOPND1;
	INSTOPND1 := INSTOPND2;
	INSTOPND2 := TMPOPND1
	end
    end (*SWAP_OPERANDS*);


function INSTR_WORDS(INSTLOC : AN_INSTREC; INSTPC : integer) : integer;(*PTZ*)
    (* Returns the number of WORDS that the instruction beginning at
      INSTLOC occupies.  During code concretization, INSTPC should be
      a good estimate of the PC at the start of the instruction (it is
      used to compute the size of jumps).  At other times INSTPC can just
      be a dummy value. Should not be trusted before ALL_CODE_EMITTED is true
      (although it will still give the best known estimate) because the
      amount of space a given instr is computed to occupy can increase up to that
      time due to increases in the number of instrs in the codestream.
      Alters MAINCODE.NWORDS and INSTLOC↑.IWDS if appropriate*)	(*28APR79 PTZ*)
								(*DATASTRCH*)
    var TWDS, JMPOFF :  integer;
	TPC :  0..MAXS1LOC;
	JDESTPTR : AN_INSTREC;

    begin
    with INSTLOC↑ do
	begin
	if (OPFMT = VJOP) and (not JUMPS_CONCRETIZED) then
	    begin 
	    TWDS := 1;
	    if INSTOPND1.XWD <> nil then
		TWDS := TWDS + 1;
	    if INSTOPND2.XWD <> nil then
		TWDS := TWDS + 1;
	    JDESTPTR := DESTPTR;
	    if PR = 1 then
		(*force two-word jump: this is in a jump table.
		  The instruction should be a JMPA so OPND1 won't
		  be extended. 2-word jump ASSERTed in CONCPAS3*)
		TWDS := 2 
	    else if JDESTPTR <> nil then
		begin
		if JDESTPTR↑.OPCODE <> XS1LOC then
		    begin
		    if ((MAINCODE.NWORDS > MAXJPROFFSET) or not ALL_CODE_EMITTED)
		      and (INSTOPND2.XWD = nil) then
			TWDS := TWDS + 1  (*not already extended OPND2, may not
					    fit PC-relative. Assume worst case*)
		    end
		else
		    begin
		    if (MAINCODE.NWORDS > MAXJPROFFSET) 
		      and (INSTOPND2.XWD = nil) then
			begin (*not already extended OPND2,
				may not fit PC-relative*)
			TPC := JDESTPTR↑.FAKEOPND;
			if TPC <> S1LOCUNDEF then
			    begin
			    JMPOFF := (TPC - INSTPC) div WORDUNITS;
			    if (JMPOFF < MINJPROFFSET)
			      or (MAXJPROFFSET < JMPOFF) then
				TWDS := TWDS + 1
			    end
			else
			    TWDS := TWDS + 1  (*not enough info yet,
						assume worst case*)
			end
		    end
		end;
	    MAINCODE.NWORDS := MAINCODE.NWORDS - IWDS + TWDS;
	    IWDS := TWDS;
	    end (* VJOP and jumps not concretized *);
	INSTR_WORDS := IWDS
	end (*with INSTLOC↑ do*)
    end (*INSTR_WORDS*);


procedure PRINTMAINCODE;                    (*28APR79 PTZ*)	(*DATASTRCH*)
    (* prints out the contents of the codestream*)

    var DEBUGPC, TDEBUGPC :  0..MAXS1LOC;
	IPTR : AN_INSTREC;

    begin
    IPTR := MAINCODE.FIRST;
    DEBUGPC := SEG_EP_RELPC;

    while IPTR <> nil do
	begin
	TDEBUGPC := DEBUGPC;    (*DISASSEMBLE changes its first param*)
(*	if (DEBUGPC > 9500) and (DEBUGPC < 10500) then	"for large files"*)
	    DISASSEMBLE(TDEBUGPC,IPTR);
	DEBUGPC := DEBUGPC + IPTR↑.IWDS*WORDUNITS;
	IPTR := IPTR↑.NEXTPTR;
	end;
    end (*PRINTMAINCODE*);
(** FIXUP_CLASS:			FIXSOP FIXJOP FIXOPND2 ADD_XWPTR_TO_OPNDXWFIXLIST**)
(**)

procedure FIXSOP(SKIPLOC, SKIPDEST :  AN_INSTREC);		(*DATASTRCH*)
    (*Set the destination pointer of the skip instruction to
     point where SKIPDEST points.*)

    begin
    if not (SKIPLOC↑.OPFMT = VSOP) then
        ASSERTFAIL('FIXSOP   001');
    SKIPLOC↑.DESTPTR := SKIPDEST;
    end (*FIXSOP*);


procedure FIXJOP(JUMPLOC, JUMPDEST :  AN_INSTREC);		(*DATASTRCH*)
    (*Set the destination pointer of the jump instruction to
     point where JUMPDEST points.*)

    begin
    if not (JUMPLOC↑.OPFMT = VJOP) then
        ASSERTFAIL('FIXJOP   001');
    JUMPLOC↑.DESTPTR := JUMPDEST;
    end (*FIXJOP*);


procedure FIXOPND2 (INSTLOC :  AN_INSTREC;  FIXVAL :  integer);	(*DATASTRCH*)
    (*Fixes the extended OPND2 field of the instruction by adding
	FIXVAL to the appropriate part of it.The operand may be an
	extended constant, a fixed-base address, or a variable-base
	address.*)

    var W :  S1WORD;
	CARRY :  BIT;
	T :  integer;
	UNKNOWN_LOC :  integer;

    begin
    if (INSTLOC↑.INSTOPND2.XWD =nil) then
        ASSERTFAIL('FIXOPND2 001');

    if (INSTLOC↑.INSTOPND2.REG = 1) and (INSTLOC↑.INSTOPND2.F > 0) then
	begin  (*extended constant*)
	(*Note : this section will be easier with real S1WORDs.*)
	INTEGER_TO_S1WORD (W, FIXVAL);
	with INSTLOC↑.INSTOPND2.XWD↑ do
	    begin
	    CARRY := 0;
	    T := VAL.RHALF + W.RHALF;
	    if T < TWOEXP[18] then VAL.RHALF := T
	    else
		begin	CARRY := 1;
		VAL.RHALF := T - TWOEXP[18];
		end;
	    T := VAL.LHALF + W.LHALF + CARRY;
	    VAL.LHALF := T mod TWOEXP[18];
	    end;
	end (*extended constant*)

    else
	with INSTLOC↑.INSTOPND2.XWD↑ do
	    if V = 0 then
		begin  (*fixed-base address*)
		T := FIXVAL + ADDR;
		if (T<MINSIGNEDS1ADDR) or (T>MAXSIGNEDS1ADDR) then
		    ERROR (WADDR_OUT_OF_RANGE);
		ADDR := T;
		end (*fixed-base address*)

	    else
		begin  (*variable-base address*)
		T := FIXVAL + DISP;
		if (T<MINS1DISP) or (T>MAXS1DISP) then
		    ERROR (WDISP_OUT_OF_RANGE);
			       (*probable cause: data area too large*)
		DISP := T;
		end (*variable-base address*);

    if TR_S1CODE then
	begin
	WRITELN (OUTPUT,
	      '      Fixup performed to produce the instruction:');
	UNKNOWN_LOC := 0;
  	DISASSEMBLE (UNKNOWN_LOC, INSTLOC); 
	end;

    end (*FIXOPND2*);



procedure ADD_XWPTR_TO_OPNDXWFIXLIST(var CL :  OPNDXWORDFIXLIST;	
				          XPTR :  AN_OPERANDXWORD); (*DATASTRCH*)
    (*Appends a new OPNDXWORDREC to the front of operandfixlist CL, containing
     pointer XPTR.*)
 
    var X :  AN_OPNDXWORDREC;

    begin
    NEWOPNDXWORDREC(X);
    X↑.XWORDPTR := XPTR;
    X↑.NEXTPTR := CL.FIRST;
    if CL.FIRST = nil then CL.LAST := X;
    CL.FIRST := X;
    CL.NWORDS := 1 + CL.NWORDS
    end (*ADD_XWPTR_TO_OPNDXWFIXLIST*);
(** FIXUP_CLASS:			ADD_INSTPTR_TO_OPND2FIXLIST AP_JUMPLIST_PLUS_ONE AP_JUMP_TO_JUMPLIST JMP_TO_TABLE_RECORD_OR_FIX JUMP_TO_LABEL_RECORD_OR_FIX OPND2_RECORD_OR_FIX **)
(**)

procedure UPD_LBLTBL (var LPTR :  A_LBLHASHENT; LNUM :	LBL_INDEX;
		      LCLASS :	LINTVAL_OR_LINSTPTR);
    forward;

procedure ADD_INSTPTR_TO_OPND2FIXLIST(var CL :  OPND2FIXLIST;
				  XINSTPTR :  AN_INSTREC);	(*DATASTRCH*)
    (*Appends a new OPND2REC to the front of opnd2fixlist CL, containing
     pointer XINSTPTR.	Obtains a new OPND2REC, but does not use
     NEWINSTREC.*)

    var X :  AN_OPND2REC;			

    begin
    NEWOPND2REC(X);
    X↑.OPND2IPTR := XINSTPTR;
    X↑.NEXTPTR := CL.FIRST;
    if CL.FIRST = nil then CL.LAST := X;
    CL.FIRST := X;
    CL.NWORDS := 1 + CL.NWORDS
    end (*ADD_INSTPTR_TO_OPND2FIXLIST*);


procedure AP_JUMPLIST_PLUS_ONE(var JL1, JL2 :	JUMPLIST;
				JUMPLOC :  AN_INSTREC);		(*DATASTRCH*)
    (*Appends JL2 onto JL1, and also appends the single jump at JUMPLOC
     in FRONT of JL1.*)

    begin
    FIXJOP(JUMPLOC,JL1.FIRST);
    if JL1.FIRST = nil then JL1.LAST := JUMPLOC;
    JL1.FIRST := JUMPLOC;
    FIXJOP(JL1.LAST,JL2.FIRST);
    if JL2.FIRST <> nil then JL1.LAST := JL2.LAST;
    JL1.NWORDS := 1 + JL1.NWORDS + JL2.NWORDS
    end (*AP_JUMPLIST_PLUS_ONE*);


procedure AP_JUMP_TO_JUMPLIST(var JL :  JUMPLIST;
			       JUMPLOC :  AN_INSTREC);		(*DATASTRCH*)
    (*Appends the single jump at JUMPLOC onto the front of JL.*)

    begin
    if not (OPFORMAT[JUMPLOC↑.OPCODE] = VJOP) then		(*PEG*)(*KYW 9/5*)
        ASSERTFAIL('AP_JUMP_T001');				(*PEG*)
    FIXJOP(JUMPLOC,JL.FIRST);
    if JL.FIRST = nil then JL.LAST := JUMPLOC;
    JL.FIRST := JUMPLOC;
    JL.NWORDS := 1 + JL.NWORDS
    end (*AP_JUMP_TO_JUMPLIST*);


procedure JMP_TO_TABLE_RECORD_OR_FIX(JUMPLOC :  AN_INSTREC;	
				      LNUM :  LBL_INDEX);	(*DATASTRCH*)
    (*Records the jump in the fixup list for this label number or else
     fixes it immediately.  Also flags label table entry as a
     jumptable label and flags the jumps in the table if the table
     already exists.*)

    var LPTR :	A_LBLHASHENT;  PTR :  AN_INSTREC;

    begin
    UPD_LBLTBL(LPTR,LNUM,LINSTPTR);
    with LPTR↑ do
	begin
	if not DEFINED then
	    AP_JUMP_TO_JUMPLIST(JLIST,JUMPLOC)
	else
	    begin (*DEFINED*)
	    FIXJOP(JUMPLOC,INSTPTR);
	    if not JUMPTABLELABEL then
		begin
		PTR := INSTPTR;
		while (PTR↑.OPCODE = XJMPA) and	 (PTR↑.INSTOPND2.XWD = nil)  do
		    begin
                    PTR↑.PR := 1;
		    PTR := PTR↑.NEXTPTR;
		    end
		end (*not JUMPTABLELABEL*)
	    end (*DEFINED*);
	JUMPTABLELABEL := true
	end (*with LPTR↑ do*)
    end (*JMP_TO_TABLE_RECORD_OR_FIX*);


procedure JMP_TO_LABEL_RECORD_OR_FIX(JUMPLOC :  AN_INSTREC;
				      LNUM :  LBL_INDEX);	(*DATASTRCH*)
    (*Records the jump in the fixup list or fixes it immediately.*)

    var LPTR :	A_LBLHASHENT;

    begin
    UPD_LBLTBL(LPTR,LNUM,LINSTPTR);
    with LPTR↑ do
	if DEFINED then
	    FIXJOP(JUMPLOC,INSTPTR)
	else
	    AP_JUMP_TO_JUMPLIST(JLIST,JUMPLOC)
    end (*JMP_TO_LABEL_RECORD_OR_FIX*);


procedure OPND2_RECORD_OR_FIX(INSTLOC :  AN_INSTREC;
			      LNUM :  LBL_INDEX);
    (*Records the instruction in the LINTVAL fixup list or fixes it
     up immediately.*)

    var LPTR :	A_LBLHASHENT;

    begin
    UPD_LBLTBL(LPTR,LNUM,LINTVAL);
    with LPTR↑ do
	if DEFINED then
	    FIXOPND2(INSTLOC,INTVAL)
	else
	    ADD_INSTPTR_TO_OPND2FIXLIST(CLIST,INSTLOC)		(*DATASTRCH*)
    end (*OPND2_RECORD_OR_FIX*);
(** OPERAND_PROCESSOR_CLASS:		ISREG IS_T_REG IS_T_RG_NOT_RT ISSHORTCONST ISCONST EQUAL_OPERANDS REG_OPERAND IMM_OPERAND REAL_IMM_OPERAND IS_RT IS_RTA IS_RTB USES_RTA USES_RTB **)
(**)

function FITS_SHRT_OFFSET (DISP :  S1DISP) :  boolean;
    forward;


function ISREG (var OPND :  OPERAND) :	boolean;
    (*Return true iff OPND specifies a register operand.*)

    begin
    ISREG := (OPND.X=0) and (OPND.REG=0);
    end (*ISREG*);



function IS_T_REG (var OPND :  OPERAND) :  boolean;
    (*Return true iff OPND specifies a register operand
	which is a temporary register (including RTA, RTB),
	as opposed to a parm or display register.*)

    begin
    IS_T_REG := (OPND.X=0) and (OPND.REG=0)
	  and (((S1RTA<=OPND.F) and (OPND.F<=succ(S1RTB)))
	      or ((MINTMPS1REG<=OPND.F) and (OPND.F<=MAXTMPS1REG)));
    end (*IS_T_REG*);



function IS_T_RG_NOT_RT (var OPND :  OPERAND) :  boolean;
    (*Return true iff OPND specifies a register operand
	which is a temporary register (excluding RTB and RTA),
	as opposed to a parm or display register.*)

    begin
    IS_T_RG_NOT_RT := (OPND.X=0) and (OPND.REG=0)
	  and (MINTMPS1REG<=OPND.F) and (OPND.F<=MAXTMPS1REG);
    end (*IS_T_RG_NOT_RT*);



function ISSHORTCONST (var OPND :  OPERAND) :  boolean;
    (*Return true iff OPND specifies a short-constant operand.*)

    begin
    ISSHORTCONST := (OPND.X=0) and (OPND.REG=1);
    end (*ISSHORTCONST*);


function ISCONST (var OPND :  OPERAND) :  boolean;
    (*Return true iff OPND specifies a constant operand.*)
    (*Note - this procedure is never used, but could be.*)

    begin
    ISCONST := ( (OPND.X=0) and (OPND.REG=1) )
	    or ( (OPND.X=1) and (OPND.REG=1) and (OPND.F<>0) );
    end (*ISCONST*);


function EQUAL_OPERANDS (var X, Y :  OPERAND) :  boolean;
    (*Return true iff two operands are equal in all fields.*)

    var EQSOFAR :  boolean;

    begin
    EQSOFAR :=
	    (X.X = Y.X)
	and (X.REG = Y.REG)
	and (X.F = Y.F)
	and (X.FIXUP = Y.FIXUP)
	and (X.FIXPTR = Y.FIXPTR)
	and (X.XW.FMT = Y.XW.FMT);
    if EQSOFAR then
	case X.XW.FMT of
	    XW_EV :
		EQSOFAR :=
			(X.XW.P = Y.XW.P)
		    and (X.XW.V = Y.XW.V)
		    and (X.XW.D = Y.XW.D)
		    and (X.XW.I = Y.XW.I)
		    and (X.XW.S = Y.XW.S)
		    and (X.XW.ADDR = Y.XW.ADDR)
		    and (X.XW.REG = Y.XW.REG)
		    and (X.XW.DISP = Y.XW.DISP);
	    XW_C :
		EQSOFAR :=
			(X.XW.VAL = Y.XW.VAL)
	end (*case*);
    EQUAL_OPERANDS := EQSOFAR
    end (*EQUAL_OPERANDS*);



procedure REG_OPERAND (var OPND :  OPERAND;  R :  S1REGISTER);
    (*Build an operand specifying register R.*)

    begin
    OPND := EMPTY_OP;
    OPND.X := 0;
    OPND.REG := 0;
    OPND.F := ord(R);
    end (*REG_OPERAND*);



procedure IMM_OPERAND (var OPND :  OPERAND;  VAL :  integer);
    (*Build an operand which specifies a constant integer value VAL.*)

    begin
    if (MINSHORTCONSTANT <= VAL) and (VAL <= MAXSHORTCONSTANT) then
	begin
	OPND := ZERO_OP;
	if not (OPND.REG=1) then ASSERTFAIL('IMM_OPERA001');
	OPND.F := VAL
	end

    else
	begin
	OPND := EXTENDED_ZERO_OP;
	INTEGER_TO_S1WORD (OPND.XW.VAL, VAL);
	end;
    end (*IMM_OPERAND*);



procedure REAL_IMM_OPERAND (var OPND :  OPERAND;  RVAL :  real); (*LCW*)
    (*Build an operand which specifies a constant real value VAL.*)

    begin
    if RVAL = 0.0 then
	OPND := ZERO_OP
    else
	begin
	OPND := EXTENDED_ZERO_OP;
	REAL_TO_S1WORD (OPND.XW.VAL, RVAL);
	end;
    end (*REAL_IMM_OPERAND*);



function IS_RT (var OPND :  OPERAND) :	boolean;
    (*Return true iff OPND specifies RTA or RTB.*)
    (*Note - this procedure is never used.*)

    begin
    IS_RT := (OPND.X=0) and (OPND.REG=0)
	     and ( (OPND.F=ord(S1RTA)) or (OPND.F=ord(S1RTB)) );
    end (*IS_RT*);



function IS_RTA (var OPND :  OPERAND) :  boolean;
    (*Return true iff OPND specifies RTA.*)

    begin
    IS_RTA := (OPND.X=0) and (OPND.REG=0)
	     and (OPND.F=ord(S1RTA));
    end (*IS_RTA*);



function IS_RTB (var OPND :  OPERAND) :  boolean;
    (*Return true iff OPND specifies RTB.*)

    begin
    IS_RTB := (OPND.X=0) and (OPND.REG=0)
	     and (OPND.F=ord(S1RTB));
    end (*IS_RTB*);



function USES_RTA(var OPND :  OPERAND) :  boolean;
    (*Return true iff the operand uses RTA.*)

    begin
    if (OPND.REG = S1RTA) or
       (OPND.REG = 0) and (OPND.F = ord(S1RTA)) then
	USES_RTA := true
    else if (OPND.X <> 1) or
	    (OPND.REG = 1) and (OPND.F <> 0) then USES_RTA := false
    else USES_RTA := (OPND.XW.V=1) and (OPND.XW.REG=S1RTA);
    end (*USES_RTA*);



function USES_RTB(var OPND :  OPERAND) :  boolean;
    (*Return true iff the operand uses RTB.*)

    begin
    if (OPND.REG = S1RTB) or
       (OPND.REG = 0) and (OPND.F = ord(S1RTB)) then
	USES_RTB := true
    else if (OPND.X <> 1) or
	    (OPND.REG = 1) and (OPND.F <> 0) then USES_RTB := false
    else USES_RTB := (OPND.XW.V=1) and (OPND.XW.REG=S1RTB);
    end (*USES_RTB*);





(** OPERAND_PROCESSOR_CLASS:	XTNDED_IMM_OPERAND REGDISP_OPERAND XTNDED_REGDISP_OPERAND EXT_REGADDR_OPERAND ADDR_OPERAND TWIDDLE_OPERAND **)
(**)

procedure XTNDED_IMM_OPERAND (var OPND :  OPERAND;  VAL :  integer);
    (*Build an extended operand which specifies
	the integer constant VAL.*)

    begin
    OPND := EXTENDED_ZERO_OP;
    INTEGER_TO_S1WORD (OPND.XW.VAL, VAL);
    end (*XTNDED_IMM_OPERAND*);



procedure REGDISP_OPERAND (var OPND :  OPERAND;
		      REG :  S1REGISTER;  DISP :  S1DISP);
    (*Build an operand specifying the address DISP(%REG). *)


    begin
    if FITS_SHRT_OFFSET(DISP) then
	begin
	OPND := EMPTY_OP;
	OPND.X := 0;
	OPND.REG := ord(REG);
	OPND.F := DISP div WORDUNITS;
	end
    else
	begin
	OPND := EMPTY_OP;
	OPND.X := 1;
	OPND.REG := 1;
	OPND.F := 0;	 (*short zero*)
	OPND.XW.FMT := XW_EV;
	OPND.XW.P := 0;
	OPND.XW.V := 1;
	OPND.XW.D := 0;
	OPND.XW.I := 0;
	OPND.XW.S := 0;
	OPND.XW.REG := ord(REG);
	OPND.XW.DISP := DISP;
	end;
    end (*REGDISP_OPERAND*);



procedure XTNDED_REGDISP_OPERAND
	   (var OPND :	OPERAND;  REG :  S1REGISTER;  DISP :  S1DISP);
    (*Build an extended operand specifying the address DISP(%REG). *)

    begin
    OPND := EMPTY_OP;
    OPND.X := 1;
    OPND.REG := 1;
    OPND.F := 0;     (*short zero*)
    OPND.XW.FMT := XW_EV;
    OPND.XW.P := 0;
    OPND.XW.V := 1;
    OPND.XW.D := 0;
    OPND.XW.I := 0;
    OPND.XW.S := 0;
    OPND.XW.REG := ord(REG);
    OPND.XW.DISP := DISP;
    end (*XTNDED_REGDISP_OPERAND*);



procedure EXT_REGADDR_OPERAND					(*EJG*)
	   (var OPND :	OPERAND;  REG :  S1REGISTER;  ADDR :  S1ADDRESS);
    (*Build an extended operand specifying the address ADDR(%REG). *)

    begin
    OPND := EMPTY_OP;
    OPND.X := 1;
    OPND.REG := 0;
    OPND.F := ord(REG);
    OPND.XW.FMT := XW_EV;
    OPND.XW.P := 0;
    OPND.XW.V := 0;
    OPND.XW.D := 0;
    OPND.XW.I := 0;
    OPND.XW.S := 0;
    OPND.XW.ADDR := ADDR;
    end (*EXT_REGADDR_OPERAND*);



procedure ADDR_OPERAND (var OPND :  OPERAND;  ADDR :  S1ADDRESS);
    (*Build an operand which specifies the absolute address ADDR.*)

    begin
    OPND := EMPTY_OP;
    OPND.X := 1;
    OPND.REG := 1;
    OPND.F := 0;     (*short zero*)
    OPND.XW.FMT := XW_EV;
    OPND.XW.P := 0;
    OPND.XW.V := 0;
    OPND.XW.D := 0;
    OPND.XW.I := 0;
    OPND.XW.S := 0;
    OPND.XW.ADDR := ADDR;
    end (*ADDR_OPERAND*);



procedure TWIDDLE_OPERAND (var OPND :  OPERAND;  TWIDDLE :  integer);
    (*Change OPND to specify a location TWIDDLE quarterwords
	from where it does now, if that is possible.*)(*peg 16MAY79*)

    begin
    if TWIDDLE <> 0 then
	if ISREG(OPND) then
	    if not (TWIDDLE mod WORDUNITS = 0) then ASSERTFAIL('TWIDDLE_O001')
	    else if not ((ord(FIRSTS1REG) <= OPND.F + (TWIDDLE div WORDUNITS))
	      and (OPND.F + (TWIDDLE div WORDUNITS) <= ord(LASTS1REG)))
		then ASSERTFAIL('TWIDDLE_O002')
	    else OPND.F := OPND.F + (TWIDDLE div WORDUNITS)

	else if (OPND.X = 0)	(*Short-indexed*)
	  and ((ord(S1RPC) <= OPND.REG) and (OPND.REG <= ord(LASTS1REG))) then
	    if FITS_SHRT_OFFSET(OPND.F*WORDUNITS + TWIDDLE) then
		OPND.F := OPND.F + (TWIDDLE div WORDUNITS)
	    else
		begin (*Convert to extended*)
		OPND.X := 1;
		OPND.XW.FMT := XW_EV;
		OPND.XW.P := 0;
		OPND.XW.V := 1;
		OPND.XW.D := 0;
		OPND.XW.I := 0;
		OPND.XW.S := 0;
		OPND.XW.REG := OPND.REG;
		OPND.XW.DISP := OPND.F*WORDUNITS + TWIDDLE;
		OPND.REG := 1;
		OPND.F := 0;
		end (*Convert to extended*)

	else if (OPND.X = 1) and (OPND.XW.I <> 1) then (*Extended addressing*)
	    begin
	    if OPND.XW.V = 0 then       (*Fixed-based*)
		OPND.XW.ADDR := OPND.XW.ADDR + TWIDDLE
	    else if OPND.XW.V = 1 then  (*Variable-based*)
		OPND.XW.DISP := OPND.XW.DISP + TWIDDLE
	    end (*Extended addressing*)

	else if not (false) then ASSERTFAIL('TWIDDLE_O003');	(*All others*)
    end (*TWIDDLE_OPERAND*);

(** REGISTER/GLOBAL_MANAGEMENT_CLASS:	ALLOCGBL FREEGBL_S ALLAREFREE ALLOCRG ALLOCRP FREERG_S FINDRGBLOCK FINDRP FINDRG MOVE_AND_FREE_RTB CURRENT_PARMREG_COUNT IS_PARMREG CHECK_DSP_TMP_COLLISION RESERVE_PARMREGS **)
(**)

procedure EMITFAKEOP(S1OPC :  S1OPCODE; OPND :  integer);	(*PBK*)
    forward;


procedure EMITXOP (S1OPC :  S1OPCODE; var OPND1, OPND2 :  OPERAND);
    forward;


procedure ALLOCGBL (G :  S1GBL);
    (*Allocates a global (ie. low-core memory word) G.*)

    begin
    if not (GISFREE[G]) then ASSERTFAIL('ALLOCGBL 001');
    GISFREE[G] := false;
    end (*ALLOCGBL*);


procedure FREEGBL_S (G :  S1GBL);
    (*Frees a global or global pair starting with word G.
	The name FREEGBL_S is intended to suggest FREEGBL(S). *)

    begin
    if not ( not GISFREE[G]) then ASSERTFAIL('FREEGBL_S001');
    GISFREE[G] := true;
    end (*FREEGBL_S*);


function ALLAREFREE(FIRSTRG, SIZE :  S1REGISTER) :  boolean;	(*PEG 14MAY79...*)
    (*Checks to see if all registers in the block starting at FIRSTRG of
	length SIZE are free.*)

    var	FREE :  boolean;
	I :  S1REGISTER;

    begin
    FREE := RISFREE[FIRSTRG];
    I := FIRSTRG + 1;
    while FREE and (I <= FIRSTRG + SIZE - 1) do
	begin
	FREE := (*FREE and*) RISFREE[I];
	I := I + 1;
	end;
    ALLAREFREE := FREE;
    end (*ALLAREFREE*);						(*...PEG 14MAY79*)


procedure ALLOCRG (R :  S1REGISTER);

    begin
    if not (RISFREE[R]) then ASSERTFAIL('ALLOCRG  001');
    RISFREE[R] := false;
    RPWORD[R] := RSINGLE;						(*PBK*)
    end (*ALLOCRG*);


procedure ALLOCRP (R :	S1REGISTER);
    begin
    if not ( RISFREE[R] and RISFREE[succ(R)] ) then ASSERTFAIL('ALLOCRP  001');
    RISFREE[R] := false;
    RISFREE[succ(R)] := false;
    RPWORD[R] := R1STOFPAIR;						(*PBK*)
    RPWORD[succ(R)] := R2NDOFPAIR;					(*PBK*)
    end (*ALLOCRP*);


procedure FREERG_S(R :	S1REGISTER);
    (*Frees a register or register pair starting with R.
	The name FREERG_S is intended to suggest FREERG(S). *)

    begin
    if (RISFREE[R]) or (RPWORD[R] = R2NDOFPAIR)
      or (RPWORD[R] = RINBLOCK) then					(*PEG*)
        ASSERTFAIL('FREERG_S 001');					(*PBK*)
    RISFREE[R] := true;
    EMITFAKEOP(XFREEREG,R);						(*PBK*)
    if RPWORD[R] = R1STOFPAIR then					(*PBK*)
	begin
	RISFREE[R+1] := true;
	EMITFAKEOP(XFREEREG,R+1)					(*PBK*)
	end (* if RPWORD[R] = R1STOFPAIR then *)			(*PBK*)
    else if RPWORD[R] = R1STOFBLOCK then		(*PEG 14MAY79...*)
	begin
	R := R + 1;
	while RPWORD[R] = RINBLOCK do
	    begin
	    RISFREE[R] := true;
	    EMITFAKEOP(XFREEREG,R);
	    R := R + 1;
	    end;
	end (*if RPWORD[R] = R1STOFBLOCK*);		(*...PEG 14MAY79*)
    end (*FREERG_S*);


procedure FINDRGBLOCK(SIZE :  S1REGISTER);		(*PEG 14MAY79...*)
    (*Find and allocate a block of temporary registers (Not RTA or RTB) of
     length SIZE.  Return the smallest reg number in global variable NXTRG.*)
    (* NOTE: THIS IS A TEMPORARY VERSION OF THIS ROUTINE.  EVENTUALLY IT
	WILL BE MUCH SMARTER, or replaced by calls to the runtime-stack temp
	routines which are yet to be written.  PEG. *)

    var	I :  S1REGISTER;

    begin
    NXTRG := MINTMPS1REG;
    while (NXTRG < MINDSPS1REG - SIZE)
	  and not ALLAREFREE(NXTRG, SIZE) do
	NXTRG := NXTRG + 1;
    if ALLAREFREE(NXTRG, SIZE) then
	begin
	RISFREE[NXTRG] := false;
	RPWORD[NXTRG] := R1STOFBLOCK;
	for I := (NXTRG + 1) to (NXTRG + SIZE - 1) do
	    begin
	    RISFREE[I] := false;
	    RPWORD[I] := RINBLOCK;
	    end;
	if (NXTRG + SIZE - 1) > MAXTMPS1REG then
	    begin
	    MAXTMPS1REG := NXTRG + SIZE - 1;
	    MAXTMPPROC := CURPROC;
	    MAXTMPPLOC := CURPLOC
	    end
	end
    else ERROR(WEXPR_TOO_COMPLEX)
    end (*FINDRGBLOCK*);				(*...PEG 14MAY79*)


procedure FINDRP;
    (*Find and allocate a pair of temporary registers (Not RTA or RTB).
     Return the smaller reg number in global variable NXTRG.*)

    begin
    NXTRG := MINTMPS1REG;
    while (NXTRG < MINDSPS1REG-2)
	  and not (RISFREE[NXTRG] and RISFREE[NXTRG+1]) do
	NXTRG := NXTRG + 1;
    if RISFREE[NXTRG] and RISFREE[NXTRG+1] then
	begin
	RISFREE[NXTRG] := false;
	RISFREE[NXTRG+1] := false;
	RPWORD[NXTRG] := R1STOFPAIR;					(*PBK*)
	RPWORD[NXTRG+1] := R2NDOFPAIR;					(*PBK*)
	if NXTRG+1 > MAXTMPS1REG then
	    begin
	    MAXTMPS1REG := NXTRG+1;
	    MAXTMPPROC := CURPROC;
	    MAXTMPPLOC := CURPLOC
	    end
	end
    else ERROR(WEXPR_TOO_COMPLEX)
    end (*FINDRP*);


procedure FINDRG;
    (*Find and allocate one of the temporary registers (Not RTA or
     RTB), trying not to split potential pairs.  Return reg number in
     global variable NXTRG.*)

    var I, ISAVE :  S1REGISTER;

    begin
    NXTRG := MINTMPS1REG;
    while (NXTRG < MINDSPS1REG-1) and not RISFREE[NXTRG] do
	NXTRG := NXTRG + 1;
    if not RISFREE[NXTRG] then
	ERROR(WEXPR_TOO_COMPLEX)
    else  (*Found a free one (NXTRG). Can we improve on it?*)
	begin
	I := NXTRG;
	while I <= MAXTMPS1REG do
	    begin
	    ISAVE := I;
	    repeat I := I + 1 until (I>MAXTMPS1REG) or not RISFREE[I];
	    if I-ISAVE = 1 then  (*I-ISAVE = num of adjacent free regs*)
		begin  (*found an isolated free reg: use it*)
		NXTRG := ISAVE;
		I := MAXTMPS1REG + 1
		end
	    else  (*skip over next group of adjacent nonfree regs*)
		while (I<=MAXTMPS1REG) and not RISFREE[I] do I := I + 1
	    end (*while I<=MAXTMPS1REG do*);
	RISFREE[NXTRG] := false;
	RPWORD[NXTRG] := RSINGLE;					(*PBK*)
	if NXTRG > MAXTMPS1REG then
	    begin
	    MAXTMPS1REG := NXTRG;
	    MAXTMPPROC := CURPROC;
	    MAXTMPPLOC := CURPLOC
	    end
	end  (*Found a free one*)
    end (*FINDRG*);


procedure MOVE_AND_FREE_RTB;
    (*We free RTB to use it to return function values or to
	pass parameters to standard procs.
	WARNING!!! This should not be called if an operand has
	been built since it could invalidate the operand.*)

    var MOVEOP :  S1OPCODE;
	OPNDR :  OPERAND;

    begin
    if not (not RISFREE[S1RTB]) then ASSERTFAIL('MOVE_AND_001');
    if RTBDOUB then
	begin FINDRP; MOVEOP := XMOV_D_D end
    else
	begin FINDRG; MOVEOP := XMOV_S_S end;
    REG_OPERAND(OPNDR,NXTRG);
    EMITXOP(MOVEOP,OPNDR,OPNDRTB);
    if not (RTBUSER <= TOP) then ASSERTFAIL('MOVE_AND_002');
    with STK[RTBUSER] do
	begin (*Update RTB datum to point to new reg*)
	if FPA.WHICH = RGS then if FPA.RGADR = S1RTB then
	    FPA.RGADR := NXTRG;
	if VPA1.VPA.WHICH = RGS then if VPA1.VPA.RGADR = S1RTB then
	    VPA1.VPA.RGADR := NXTRG;
	if VPA2.VPA.WHICH = RGS then if VPA2.VPA.RGADR = S1RTB then
	    VPA2.VPA.RGADR := NXTRG
	end;
    FREERG_S(S1RTB)
    end (*MOVE_AND_FREE_RTB*);


function CURRENT_PARMREG_COUNT :  NUMBER_OF_PAREGS;
    (*Returns the current number of parameter registers.*)

    begin
    CURRENT_PARMREG_COUNT := MINTMPS1REG - MINPARS1REG
    end (*CURRENT_PARMREG_COUNT*);


function IS_PARMREG (R :  S1REGISTER) :  boolean;
    (*Returns true iff R is a parameter register.*)

    begin
    IS_PARMREG := (MINPARS1REG<=R) and (R<MINTMPS1REG);
    end (*IS_PARMREG*);


procedure CHECK_DSP_TMP_COLLISION;
    (*Checks to see if there is a collision between the display
     registers and the temporary registers.  If so, an error message
     is given; this is a non-recoverable situation requiring the user
     to either simplify expressions or un-nest procedures.*)

    begin
    if MINDSPS1REG <= MAXTMPS1REG then
	ERROR(WNESTING_TOO_DEEP_OR_EXPRESSION_TOO_COMPLEX)
    end (*CHECK_DSP_TMP_COLLISION*);


procedure RESERVE_PARMREGS(COUNT :  NUMBER_OF_PAREGS);
    (*Changes the reservation to a given number of the parameter
     registers, after asserting that any newly reserved ones are
     available.*)

    var I :  S1REGISTER;

    begin
    for I := MINTMPS1REG to MINPARS1REG+COUNT-1 do
	if not (RISFREE[I]) then ASSERTFAIL('RESERVE_P001');
    MINTMPS1REG := MINPARS1REG + COUNT;
    MAXTMPS1REG := MAX(MAXTMPS1REG,MINTMPS1REG-1);
    CHECK_DSP_TMP_COLLISION
    end (*RESERVE_PARMREGS*);

(** REGISTER/GLOBAL_MANAGEMENT_CLASS:	FREEDATUMREGS FREEREGSBUTONE FREERGSBUTSOME FREEVPAREG FREVPARGUNLESS FREE_TEMP_REGS **)
(**)

procedure FREEDATUMREGS (STE :	STKINX);
    (*Free all the temp expr regs (not display or parm regs)
	used in the datum.  Does *not* change the datum.*)

    begin
    if (STK[STE].FPA.WHICH=RGS) then
	if (MINTMPS1REG<=STK[STE].FPA.RGADR) and
	   (STK[STE].FPA.RGADR<=MAXTMPS1REG) or
	   (STK[STE].FPA.RGADR in [S1RTA, S1RTB]) then
	    FREERG_S (STK[STE].FPA.RGADR);
    if STK[STE].NVPAS >= 1 then
      if (STK[STE].VPA1.VPA.WHICH=RGS) then
	if (MINTMPS1REG<=STK[STE].VPA1.VPA.RGADR) and
	   (STK[STE].VPA1.VPA.RGADR<=MAXTMPS1REG) or
	   (STK[STE].VPA1.VPA.RGADR in [S1RTA, S1RTB]) then
		FREERG_S(STK[STE].VPA1.VPA.RGADR);
    if STK[STE].NVPAS = 2 then
      if (STK[STE].VPA2.VPA.WHICH=RGS) then
	if (MINTMPS1REG<=STK[STE].VPA2.VPA.RGADR) and
	   (STK[STE].VPA2.VPA.RGADR<=MAXTMPS1REG) or
	   (STK[STE].VPA2.VPA.RGADR in [S1RTA, S1RTB]) then
	    FREERG_S (STK[STE].VPA2.VPA.RGADR);
    end (*FREEDATUMREGS*);



procedure FREEREGSBUTTHESE (STE :  STKINX;  REGS :  SETOFS1REGS);
    (*Free all the temp expr regs used in the datum,
	*except* do not free registers in REGS if used.*)(*PEG*)

    begin
    with STK[STE] do
	begin
	if (FPA.WHICH=RGS) then
	    if not (FPA.RGADR in REGS) then
		if (MINTMPS1REG<=FPA.RGADR) and
		   (FPA.RGADR<=MAXTMPS1REG) or
		   (FPA.RGADR in [S1RTA, S1RTB]) then
		    FREERG_S (FPA.RGADR);
	if NVPAS >= 1 then
	  if (VPA1.VPA.WHICH=RGS) then
	    if not (VPA1.VPA.RGADR in REGS) then
		if (MINTMPS1REG<=VPA1.VPA.RGADR) and
		   (VPA1.VPA.RGADR<=MAXTMPS1REG) or
		   (VPA1.VPA.RGADR in [S1RTA, S1RTB]) then
			FREERG_S(VPA1.VPA.RGADR);
	if NVPAS = 2 then
	  if (VPA2.VPA.WHICH=RGS) then
	    if not (VPA2.VPA.RGADR in REGS) then
		if (MINTMPS1REG<=VPA2.VPA.RGADR) and
		   (VPA2.VPA.RGADR<=MAXTMPS1REG) or
		   (VPA2.VPA.RGADR in [S1RTA, S1RTB]) then
		    FREERG_S (VPA2.VPA.RGADR);
	end (*with STK[STE]*)
    end (*FREEREGSBUTTHESE*);



(*NOTE - This procedure is never used.  If it is used in the future, it
	 should be carefully checked for discrepencies (in other words,
	 it is not guaranteed to have been maintained)....

procedure FREERGSBUTSOME (STE, STE2 :	STKINX);
    %*Free all temp expr regs used in STK[STE], *except*
	do not free any used in STK[STE2]. *\

    var DONTFREE :  set of S1REGISTER;

    begin
    DONTFREE := [ ];
    if STK[STE].FPA.WHICH=MEM then
	DONTFREE := DONTFREE + [STK[STE].FPA.RGADR];
    if STK[STE].VPA1.VPA.WHICH=MEM then
	DONTFREE := DONTFREE + [STK[STE].VPA1.VPA.RGADR];
    if STK[STE].VPA2.VPA.WHICH=MEM then
	DONTFREE := DONTFREE + [STK[STE].VPA2.VPA.RGADR];
    if (STK[STE].FPA.WHICH=RGS) then
	if not (STK[STE].FPA.RGADR in DONTFREE) then
	    if (MINTMPS1REG<=STK[STE].FPA.RGADR) and
	       (STK[STE].FPA.RGADR<=MAXTMPS1REG) or
	       (STK[STE].FPA.RGADR in [S1RTA, S1RTB]) then
		FREERG_S (STK[STE].FPA.RGADR);
    if STK[STE].NVPAS >= 1 then
      if (STK[STE].VPA1.VPA.WHICH=RGS) then
	if not (STK[STE].VPA1.VPA.RGADR in DONTFREE) then
	    if (MINTMPS1REG<=STK[STE].VPA1.VPA.RGADR) and
	       (STK[STE].VPA1.VPA.RGADR<=MAXTMPS1REG) or
	       (STK[STE].VPA1.VPA.RGADR in [S1RTA, S1RTB]) then
		    FREERG_S(STK[STE].VPA1.VPA.RGADR);
    if STK[STE].NVPAS = 2 then
      if (STK[STE].VPA2.VPA.WHICH=RGS) then
	if not (STK[STE].VPA2.VPA.RGADR in DONTFREE) then
	    if (MINTMPS1REG<=STK[STE].VPA2.VPA.RGADR) and
	       (STK[STE].VPA2.VPA.RGADR<=MAXTMPS1REG) or
	       (STK[STE].VPA2.VPA.RGADR in [S1RTA, S1RTB]) then
		FREERG_S (STK[STE].VPA2.VPA.RGADR);
    end %*FREERGSBUTSOME*\;

...end of unused procedure.*)



procedure FREEVPAREG (var V :  VPAREC);
    (*Free the temp expr reg used in V, if any.  Does not change V.*)

    begin
    if V.VPA.WHICH = RGS then
	if (MINTMPS1REG <= V.VPA.RGADR) and
	   (V.VPA.RGADR <= MAXTMPS1REG) or
	   (V.VPA.RGADR in [S1RTA, S1RTB]) then
	    FREERG_S (V.VPA.RGADR);
    end (*FREEVPAREG*);



procedure FREVPARGUNLESS (var V :  VPAREC;  R :  S1REGISTER);
    (*Free the temp expr reg used in V, if any, *EXCEPT* does
	not free R if used.  Does not change V.*)

    begin
    if V.VPA.WHICH = RGS then
	if V.VPA.RGADR <> R then
	    if (MINTMPS1REG <= V.VPA.RGADR) and
	       (V.VPA.RGADR <= MAXTMPS1REG) or
	       (V.VPA.RGADR in [S1RTA, S1RTB]) then
		FREERG_S (V.VPA.RGADR);
    end (*FREVPARGUNLESS*);



procedure FREE_TEMP_REGS;
    (*Release all the temp expr regs, including RTA and RTB.*)

    var R :  S1REGISTER;

    begin
    if not RISFREE[S1RTA] then FREERG_S (S1RTA);
    if not RISFREE[S1RTB] then FREERG_S (S1RTB);
    for R := MINTMPS1REG to MAXTMPS1REG do
	if not RISFREE[R] then FREERG_S (R);
    end (*FREETEMPREGS*);

(** FORM_CODE CLASS:			FORM_CW_OPERAND FORMFAKEINST FORMSOP FORMJOP FORMTOP FORMXOP
(**)								(*DATASTRCH*)

procedure FORM_CW_OPERAND(BUFINX : INSTBUFINX;   		(*DATASTRCH*)
			  var OPND : INSTOPND;
			  SHORTSTARTBIT : S1BITNUM);
    (*Build an bit coded S1 operand from OPND in S1INSTBUF[S1INST]
     and S1INSTBUF[BUFINX].
     Position the first bit of the short part at bit SHORTSTARTBIT in
     S1INSTBUF[S1INST]; leave other 24 bits alone.  *)
    var X : BIT;
 
    begin
    if OPND.XWD <> nil then X := 1
    else X := 0;
   
    PUTFIELD(S1INSTBUF[S1INST],SHORTSTARTBIT+OPNDX_START,OPNDX_LEN,X);
    PUTFIELD(S1INSTBUF[S1INST],
		SHORTSTARTBIT+OPNDREG_START,OPNDREG_LEN,OPND.REG);
    PUTFIELD(S1INSTBUF[S1INST],SHORTSTARTBIT+OPNDF_START,OPNDF_LEN,OPND.F);
   
    if X = 1 then
	begin (*extended word*)
	if OPND.XWD↑.FMT = XW_C then
	    begin
	    if not ((OPND.F > 0) and (OPND.REG = 1)) then
		     ASSERTFAIL('OPND_CW__001');
	    S1INSTBUF[BUFINX] := OPND.XWD↑.VAL
	    end
	else (*extended address*)
	    begin
	    if not (not ((OPND.F > 0) and (OPND.REG = 1))) then
			  ASSERTFAIL('FORM_CW__002');
	    PUTFIELD(S1INSTBUF[BUFINX],XWP_START,XWP_LEN,OPND.XWD↑.P);
	    PUTFIELD(S1INSTBUF[BUFINX],XWV_START,XWV_LEN,OPND.XWD↑.V);
	    PUTFIELD(S1INSTBUF[BUFINX],XWD_START,XWD_LEN,OPND.XWD↑.D);
	    PUTFIELD(S1INSTBUF[BUFINX],XWI_START,XWI_LEN,OPND.XWD↑.I);
	    PUTFIELD(S1INSTBUF[BUFINX],XWS_START,XWS_LEN,OPND.XWD↑.S);
	    if OPND.XWD↑.V = 0 then
		PUTFIELD(S1INSTBUF[BUFINX],
			 XWADDR_START,XWADDR_LEN,OPND.XWD↑.ADDR)
	    else
		begin
		PUTFIELD(S1INSTBUF[BUFINX],
			 XWREG_START,XWREG_LEN,OPND.XWD↑.REG);
		PUTFIELD(S1INSTBUF[BUFINX],
			 XWDISP_START,XWDISP_LEN,OPND.XWD↑.DISP)
		end
	    end (*extended address*);
	end (*extended word*)
    end (*FORM_CW_OPND*);
 
 
procedure FORMFAKEINST( IPTR : AN_INSTREC ); 			(*DATASTRCH*)
    (*generate a bit coded fake S1 instruction in CODEBUF*)

    begin
    PUTFIELD(S1INSTBUF[S1INST],OPCODE_START,OPCODE_LEN,
	     HARDOPCODE[IPTR↑.OPCODE]);
    PUTFIELD(S1INSTBUF[S1INST],FAKEOPND_START,FAKEOPND_LEN,
	     IPTR↑.FAKEOPND);
    end (*FORMFAKEINST*);


procedure FORMSOP(IPTR : AN_INSTREC);				(*DTATSTRCH*)
    (*generate a bit coded SOP S1 instruction in CODEBUF*)

    begin 
    PUTFIELD(S1INSTBUF[S1INST],OPCODE_START,OPCODE_LEN,
	     HARDOPCODE[IPTR↑.OPCODE]);
    PUTFIELD(S1INSTBUF[S1INST],SKP_START,SKP_LEN,IPTR↑.SKP);

    FORM_CW_OPERAND(S1OPND2XWD,IPTR↑.INSTOPND2, OPND2_START);
    FORM_CW_OPERAND(S1OPND1XWD,IPTR↑.INSTOPND1, OPND1_START);
    end (*FORMSOP*);


procedure FORMJOP(IPTR : AN_INSTREC);				(*DATASTRCH*)
    (*generate a bit coded JOP  S1 instruction in CODEBUF*)

    begin
    PUTFIELD(S1INSTBUF[S1INST],OPCODE_START,OPCODE_LEN,
	     HARDOPCODE[IPTR↑.OPCODE]);
    PUTFIELD(S1INSTBUF[S1INST],PR_START,PR_LEN,IPTR↑.PR);

    if ((JUMPS_CONCRETIZED and (IPTR↑.PR = 0))
	or (not JUMPS_CONCRETIZED)) then
	FORM_CW_OPERAND(S1OPND2XWD,IPTR↑.INSTOPND2,OPND2_START)
    else (*PR = 1*)
	PUTFIELD (S1INSTBUF[S1INST],J_START,J_LEN,IPTR↑.J);

    FORM_CW_OPERAND(S1OPND1XWD,IPTR↑.INSTOPND1,OPND1_START);
    end (*FORMJOP*);
 

procedure FORMTOP(IPTR : AN_INSTREC);				(*DATASTRCH*)
    (*generate a bit coded TOP S1 instruction in CODEBUF*)

    begin
    PUTFIELD(S1INSTBUF[S1INST],OPCODE_START,OPCODE_LEN,
	     HARDOPCODE[IPTR↑.OPCODE]);
    PUTFIELD(S1INSTBUF[S1INST],T_START,T_LEN,IPTR↑.T);

    FORM_CW_OPERAND(S1OPND2XWD,IPTR↑.INSTOPND2, OPND2_START);
    FORM_CW_OPERAND(S1OPND1XWD,IPTR↑.INSTOPND1, OPND1_START);
    end (*FORMTOP*);


procedure FORMXOP(IPTR : AN_INSTREC); 				(*DATASTRCH*)
    (*generate a bit coded XOP S1 instruction in CODEBUF*)

    begin
    PUTFIELD(S1INSTBUF[S1INST],OPCODE_START,OPCODE_LEN,
	     HARDOPCODE[IPTR↑.OPCODE]);

    FORM_CW_OPERAND(S1OPND2XWD,IPTR↑.INSTOPND2, OPND2_START);
    FORM_CW_OPERAND(S1OPND1XWD,IPTR↑.INSTOPND1, OPND1_START);
    end (*FORMXOP*);
(** CODE_EMITTER_CLASS:			CONNECT_TO_FIXUP_LIST EMIT_INSTR_OPNDS INSERT_INSTR_OPNDS **)
(**)
(* procedure BUILD_CW_OPERAND is substituted by CONNECT_TO_FIXUP_LIST *)
procedure CONNECT_TO_FIXUP_LIST(var OPND :OPERAND; XPTR : AN_OPERANDXWORD);
    (*Add a pointer to OPERANDXWORD of OPND to a fixup list*)
								(*DATASTRCH*)
    begin
    if not (OPND.X = 1) then ASSERTFAIL('CONN_FIX 001');
    case OPND.FIXUP of
	STRINGFIX : ADD_XWPTR_TO_OPNDXWFIXLIST(STRINGFIXLIST,XPTR);
	   SETFIX : ADD_XWPTR_TO_OPNDXWFIXLIST(   SETFIXLIST,XPTR);
	  REALFIX : ADD_XWPTR_TO_OPNDXWFIXLIST(  REALFIXLIST,XPTR);
         BOUNDFIX : ADD_XWPTR_TO_OPNDXWFIXLIST(BOUNDFIXLIST,XPTR);
       XTRNSYMFIX : ADD_XWPTR_TO_OPNDXWFIXLIST(OPND.FIXPTR↑.FIXLIST,XPTR);
	  end(*case*)
    end(*CONNECT_TO_FIXUP_LIST*);


procedure EMIT_INSTR_OPNDS(var OPND1, OPND2 :  OPERAND; IWORDS : IWDRNG);
								(*DATASTRCH*)
    (*Common to EMIT routines.	Fill in all the   operand fields (at
     NEWINSTREC), emit the instr. record, and allocate and connect to 
     NEWINSTREC↑.INSTOPND1 and 2  extended words if necessary.
     Update MAINCODE to reflect     insertions.*)

    var TXWORDPTR : AN_OPERANDXWORD;

    begin
    if MAINCODE.FIRST = nil then  
	begin
        MAINCODE.FIRST := NEWINSTREC;
	NEWINSTREC↑.PREVPTR := nil
	end
    else
        begin
        MAINCODE.LAST↑.NEXTPTR := NEWINSTREC;
        NEWINSTREC↑.PREVPTR := MAINCODE.LAST
	end;
    MAINCODE.LAST := NEWINSTREC;
    NEWINSTREC↑.NEXTPTR := nil;
 
    if OPND2.X = 1 then
	begin(*extended operand2 *)
	new(TXWORDPTR);
	TXWORDPTR↑ := OPND2.XW;
	IWORDS := IWORDS + 1;
	end
    else TXWORDPTR := nil;
    with NEWINSTREC↑.INSTOPND2 do
	begin
	REG := OPND2.REG;
	F := OPND2.F;
	XWD := TXWORDPTR;
	end;
    if OPND2.FIXUP <> NOFIX then
	CONNECT_TO_FIXUP_LIST(OPND2, TXWORDPTR);

    if OPND1.X = 1 then
    	begin (*extended operand1 *)
	new(TXWORDPTR);
	TXWORDPTR↑ := OPND1.XW;
	IWORDS := IWORDS + 1
	end
    else TXWORDPTR := nil;
    with NEWINSTREC↑.INSTOPND1 do
	begin
	REG := OPND1.REG;
	F := OPND1.F;
	XWD := TXWORDPTR
	end;
    if OPND1.FIXUP <> NOFIX then
	CONNECT_TO_FIXUP_LIXT(OPND1,TXWORDPTR);

    NEWINSTREC↑.IWDS := IWORDS;
    MAINCODE.NWORDS := MAINCODE.NWORDS + IWORDS;	(*28AUG79 PTZ*)
    MAKE_NEWINSTREC(NEWINSTREC);
    end(*EMIT_INSTR_OPNDS*);


procedure INSERT_INSTR_OPNDS(var WHERE, TPTR: AN_INSTREC;
			      var OPND1, OPND2 : OPERAND; IWORDS : IWDRNG);
							(*DATASTRCH*)
    (*Common to EMIT routines.	Fill in all the short operand fields in    
     TPTR↑. insert TPTR↑  immediately following WHERE (at
     front if WHERE = nil), and allocate and connect to TPTR↑.INSTOPND1 and 2
     if needed.  Return a pointer to the last INSTREC inserted in WHERE.
     Update MAINCODE to reflect insertions.  Does Not touch
     NEWINSTREC.*)

    var TXWORDPTR : AN_OPERANDXWORD;

    begin
    if WHERE = nil then
	begin
	TPTR↑.NEXTPTR := MAINCODE.FIRST;
	TPTR↑.PREVPTR := nil;
	if not (MAINCODE.FIRST = nil) then  MAINCODE.FIRST↑.PREVPTR := TPTR;
	MAINCODE.FIRST := TPTR;
	end(*WHERE = nil*)
    else
	begin
	if not (MAINCODE.FIRST <> nil) then ASSERTFAIL('INSERT_IN001');
	TPTR↑.NEXTPTR := WHERE↑.NEXTPTR;
	TPTR↑.PREVPTR := WHERE;
        if WHERE↑.NEXTPTR <> nil then				(*29AUG79 PTZ*)
	    WHERE↑.NEXTPTR↑.PREVPTR := TPTR;
	WHERE↑.NEXTPTR := TPTR;
	end(*WHERE <> nil*);
    if MAINCODE.LAST = WHERE then MAINCODE.LAST := TPTR;
    WHERE := TPTR;

    if OPND2.X = 1 then 
	begin(*extended operand2*)
	new(TXWORDPTR);
	TXWORDPTR↑ := OPND2.XW;
	IWORDS := IWORDS + 1;
	end
    else TXWORDPTR := nil;
    with TPTR↑.INSTOPND2 do
	begin
	REG := OPND2.REG;
	F:= OPND2.F;
	XWD := TXWORDPTR
	end;
    if OPND2.FIXUP <> NOFIX then
	CONNECT_TO_FIXUP_LIST(OPND2, TXWORDPTR);

    if OPND1.X = 1 then
	begin(*extended OPND1*)
	new(TXWORDPTR);
	TXWORDPTR↑ := OPND1.XW;
	IWORDS := IWORDS + 1;
	end
    else TXWORDPTR := nil;
    with TPTR↑.INSTOPND1 do
	begin
	REG := OPND1.REG;
	F := OPND1.F;
	XWD := TXWORDPTR;
	end;
    if OPND1.FIXUP <> NOFIX then
	CONNECT_TO_FIXUP_LIST(OPND1,TXWORDPTR);

    TPTR↑.IWDS := IWORDS;
    MAINCODE.NWORDS := MAINCODE.NWORDS + IWORDS		(*28AUG79 PTZ*)
    end (*INSERT_INSTR_OPNDS*);
(** CODE_EMITTER_CLASS:			EMITFAKEOP INSERTSOP INSERTJOP INSERTXOP EMIT_S1WORD EMIT_ZEROS1WORD **)
(**)

procedure EMITFAKEOP(* (S1OPC :  S1OPCODE; OPND :  integer) *);	(*PBK*)
   (*Emit the fake S1 instruction described.*)			(*DATASTRCH*)

    begin
    if not (OPFORMAT[S1OPC] = VFAKEOP) then ASSERTFAIL('EMITFAKEI001');
    with NEWINSTREC↑ do
	begin
	OPCODE := S1OPC;
	OPFMT := VFAKEOP;
	FAKEOPND := OPND;
	IWDS := 0
	end;
   if MAINCODE.FIRST = nil then
   	begin
	MAINCODE.FIRST := NEWINSTREC;
	NEWINSTREC↑.PREVPTR := nil
	end
    else
	begin
	MAINCODE.LAST↑.NEXTPTR := NEWINSTREC;
	NEWINSTREC↑.PREVPTR := MAINCODE.LAST
	end;
    MAINCODE.LAST := NEWINSTREC;
    NEWINSTREC↑.NEXTPTR := nil;
    MAKE_NEWINSTREC(NEWINSTREC);

    end (*EMITFAKEOP*);


procedure INSERTSOP(WHERE :  AN_INSTREC;  S1OPC :  S1OPCODE;
		    SKIPDIST :	S1SKIPDISTANCE;
		    var OPND1, OPND2 :	OPERAND;
              	    SKIPDEST :	AN_INSTREC);			(*DATASTRCH*)
    (*Insert the described SOP instruction after the instrec
	that WHERE points to, updating MAINCODE to reflect changes.
	Does not use NEWINSTREC.  WHERE=nil means insert at front.*)

    var IWORDS : IWDRNG;
       	TINSTRPTR :	AN_INSTREC;

    begin
    if not ( OPFORMAT[S1OPC] = VSOP) then ASSERTFAIL('INSERTSOP001');
    MAKE_NEWINSTREC(TINSTRPTR);
    with TINSTRPTR↑ do
	begin
	OPCODE := S1OPC;
	OPFMT := VSOP;
	SKP := SKIPDIST;
	DESTPTR := SKIPDEST;
  	DUMMYSPACE := 0;  			(*2SEP79 PTZ*)
	end;
    IWORDS := 1;
    INSERT_INSTR_OPNDS(WHERE, TINSTRPTR, OPND1,OPND2, IWORDS);
    end (*INSERTSOP*);


procedure INSERTJOP(WHERE :  AN_INSTREC; S1OPC : S1OPCODE;
		    FORCELONG :  BIT; var OPND1, OPND2 :  OPERAND;
		    JUMPDEST :	AN_INSTREC);			(*DATASTRCH*)
    (*Insert the described JOP instruction after the INSTREC that WHERE
     points to, updating MAINCODE to reflect changes.  Does Not use
     NEWINSTREC.  WHERE = nil means insert at front.*)

    var IWORDS : IWDRNG;
	TINSTPTR : AN_INSTREC;
	DUMMYPC : integer;					(*KYW 8/28/79*)

    begin
    if not (OPFORMAT[S1OPC] = VJOP) then ASSERTFAIL('INSERTJOP001');
    MAKE_NEWINSTREC(TINSTPTR);
    with TINSTPTR↑ do
	begin
	OPCODE := S1OPC;
	OPFMT := VJOP;
	PR := FORCELONG;
	J := 0;
	DESTPTR := JUMPDEST;
  	DUMMYSPACE := 0;  				(*2SEP79 PTZ*)
	end;
    IWORDS := 1;
    INSERT_INSTR_OPNDS(WHERE, TINSTPTR, OPND1,OPND2,IWORDS);

    DUMMYPC := 0;						(*KYW 8/28/79*)
    WHERE↑.IWDS := INSTR_WORDS(WHERE,DUMMYPC);			(*KYW 8/28/79*)
(* WHERE↑.IWDS is changed also by side effect *)		(*KYW 8/28/79*)
(* MAINCODE.NWORDS is updatd by INSTR_WORDS in this case.*)
    end (*INSERTJOP*);


procedure INSERTXOP(WHERE :  AN_INSTREC;  S1OPC :  S1OPCODE;
		    var OPND1, OPND2 :	OPERAND);		(*DATASTRCH*)
    (*Insert the described XOP instruction after the coderec
	that WHERE points to, updating MAINCODE to reflect changes.
	Does not use NEWINSTREC.  WHERE=nil means insert at front.*)

    var IWORDS : IWDRNG;
        TINSTPTR : AN_INSTREC;

    begin
    if not ( OPFORMAT[S1OPC] = VXOP) then ASSERTFAIL('INSERTXOP001');
    MAKE_NEWINSTREC(TINSTPTR);
    with TINSTPTR↑ do
	begin
	OPCODE := S1OPC;
	OPFMT := VXOP;
	end;
    IWORDS := 1;
    INSERT_INSTR_OPNDS(WHERE, TINSTPTR, OPND1, OPND2, IWORDS);
    end (*INSERTXOP*);


procedure EMIT_S1WORD(var LIST :  CODELIST; var W :  S1WORD);
    (*Add the word to the end of the codelist.*)

    begin
    if LIST.NWORDS = 0 then
	begin
	NEWCODEREC(LIST.FIRST);
	LIST.LAST := LIST.FIRST;
	LIST.NWORDS := 1
	end
    else
	begin
	NEWCODEREC(LIST.LAST↑.NEXTPTR);
	LIST.LAST := LIST.LAST↑.NEXTPTR;
	LIST.NWORDS := LIST.NWORDS + 1
	end;

    LIST.LAST↑.NEXTPTR := nil;
    LIST.LAST↑.CODEWORD := W

    end (*EMIT_S1WORD*);


procedure EMIT_ZEROS1WORD(var LIST :  CODELIST;
			  var WHERE :  A_CODEREC);
    (*Add a zero S1WORD to the end of LIST, returning a pointer to it.*)

    begin
    if LIST.NWORDS = 0 then
	begin
	NEWCODEREC(LIST.FIRST);
	LIST.LAST := LIST.FIRST;
	LIST.NWORDS := 1
	end
    else
	begin
	NEWCODEREC(LIST.LAST↑.NEXTPTR);
	LIST.LAST := LIST.LAST↑.NEXTPTR;
	LIST.NWORDS := LIST.NWORDS + 1
	end;

    LIST.LAST↑.NEXTPTR := nil;
    LIST.LAST↑.CODEWORD := ZEROS1WORD;

    WHERE := LIST.LAST

    end (*EMIT_ZEROS1WORD*);
(** CODE_EMITTER_CLASS:			EMITSOP EMITJOP EMITTOP EMITXOP ALLOC_AND_EMIT_TOP **)
(**)

procedure EMITSOP(S1OPC :  S1OPCODE; SKIPDIST :  S1SKIPDISTANCE;
		  var OPND1, OPND2 :  OPERAND; SKIPDEST :  AN_INSTREC);
    (*Add described SOP instr to the end of MAINCODE.*)		(*DATASTRCH*)

    var IWORDS : IWDRNG;

    begin
    if not (OPFORMAT[S1OPC] = VSOP) then ASSERTFAIL('EMITSOP  001');
    with NEWINSTREC↑ do
	begin
	OPCODE := S1OPC;
	OPFMT := VSOP;
	SKP := SKIPDIST;
	DESTPTR := SKIPDEST;
  	DUMMYSPACE := 0;  				(*2SEP79 PTZ*)
	end;
    IWORDS := 1;
    EMIT_INSTR_OPNDS(OPND1,OPND2,IWORDS);
    end (*EMITSOP*);


procedure EMITJOP(S1OPC :  S1OPCODE;  FORCELONG :  BIT;
		  var OPND1, OPND2 :  OPERAND; JUMPDEST :  AN_INSTREC);
    (*Add described JOP instr to the end of MAINCODE.
      FORCELONG = 1 means that the
     jump must be concretized into a two word instruction (or a one
     word instr and a one word no-op).	This bit of information is
     stored for the time being in the PR field.*)		(*DATASTRCH*)

    var IWORDS : IWDRNG;
        DUMMYPC : integer; (*used just to match the parameter,does not contain 
			     useful information*)  (*KYW 8/28/79*)

    begin
    if not (OPFORMAT[S1OPC] = VJOP) then ASSERTFAIL('EMITJOP  001');
    with NEWINSTREC↑ do
	begin
	OPCODE := S1OPC;
	OPFMT := VJOP;
	PR := FORCELONG;
	J := 0;
 	DESTPTR := JUMPDEST;				(*2SEP79 PTZ*)
  	DUMMYSPACE := 0;  
	end;
    IWORDS := 1;
    EMIT_INSTR_OPNDS(OPND1, OPND2, IWORDS);
    DUMMYPC := 0;						 (*KYW 8/28/79*)
    MAINCODE.LAST↑.IWDS := INSTR_WORDS(MAINCODE.LAST,DUMMYPC);	 (*KYW 8/29/79*)
(* MAINCODE.LAST↑.IWDS is changed also by side effect*)
(* MAINCODE.NWORDS is updated by INSTR_WORDS in this case*)    
    end (*EMITJOP*);


procedure EMITTOP(S1OPC :  S1OPCODE;  TEMPT :  TWOBITS;
		  var OPND1, OPND2 :  OPERAND);			(*DATASTRCH*)
    (*Add described TOP instr to end of MAINCODE.*)

    var IWORDS : IWDRNG;

    begin
    if not (OPFORMAT[S1OPC] = VTOP) then ASSERTFAIL('EMITTOP  001');
    with NEWINSTREC↑ do
	begin
	OPCODE := S1OPC;
	OPFMT := VTOP;
	T := TEMPT;
	end;
    IWORDS := 1;
    EMIT_INSTR_OPNDS(OPND1,OPND2,IWORDS);
    end (*EMITTOP*);


procedure EMITXOP(*(S1OPC :  S1OPCODE; var OPND1, OPND2 :  OPERAND)*);
    (*Add described XOP instr to end of MAINCODE.*)		(*DATASTRCH*)

    var IWORDS : IWDRNG;

    begin
    if not (OPFORMAT[S1OPC] = VXOP) then ASSERTFAIL('EMITXOP  001');
    with NEWINSTREC↑ do
     	begin
	OPCODE := S1OPC;
	OPFMT := VXOP;
	end;
    IWORDS := 1;
    EMIT_INSTR_OPNDS(OPND1,OPND2,IWORDS);
    end (*EMITXOP*);


procedure ALLOC_AND_EMIT_TOP(var R :  S1REGISTER; OPCD :  S1OPCODE;
			     var OPND1, OPND2 : OPERAND;
			     DOUBRES, DOUB1, DOUB2 :  boolean;
			     STE :  STKINX);
    (*Allocate a register (returned in R) for the result of a TOP,
     perhaps emitting a MOV to free it, and emit the TOP.  Assume that
     OPND1 and OPND2 regs were Not freed in advance, but will be freed
     after return, being careful to not free reg R even if it
     coincides with OPND1 or OPND2.
     Note: DOUBRES, DOUB1, DOUB2 are true iff the result, opnd1,
     and opnd2 respectively are doublewords.  This can be deduced
     from the opcode if the proper tables are declared.*)

    var OPNDR :  OPERAND;
	MOVEOP :  S1OPCODE;

    begin
    if not ( REVERSE_OP[OPCD]<>XILLEGAL) then ASSERTFAIL('ALLOC_AND001');
    if IS_T_RG_NOT_RT(OPND1) and (DOUBRES <= DOUB1) then
	begin
	if IS_T_RG_NOT_RT(OPND2) and
	   (DOUBRES <= DOUB2) and (OPND2.F < OPND1.F) then
	    begin
	    R := OPND2.F;
	    EMITTOP (REVERSE_OP[OPCD], 0, OPND2, OPND1);
	    if DOUB2 and not DOUBRES then
		begin
		FREERG_S (R);
		ALLOCRG (R);
		end;
	    end
	else
	    begin
	    R := OPND1.F;
	    EMITTOP (OPCD, 0, OPND1, OPND2);
	    if DOUB1 and not DOUBRES then
		begin
		FREERG_S (R);
		ALLOCRG (R);
		end;
	    end
	end
    else if IS_T_RG_NOT_RT(OPND2) and (DOUBRES <= DOUB2) then
	begin
	R := OPND2.F;
	EMITTOP (REVERSE_OP[OPCD], 0, OPND2, OPND1);
	if DOUB2 and not DOUBRES then
	    begin
	    FREERG_S (R);
	    ALLOCRG (R);
	    end;
	end
    else if IS_RTA(OPND1) then
	begin
	if DOUBRES then FINDRP else FINDRG;
	R := NXTRG;   REG_OPERAND (OPNDR, R);
	EMITTOP (OPCD, 1, OPNDR, OPND2);
	end
    else if IS_RTA(OPND2) then
	begin
	if DOUBRES then FINDRP else FINDRG;
	R := NXTRG;   REG_OPERAND (OPNDR, R);
	EMITTOP (REVERSE_OP[OPCD], 1, OPNDR, OPND1);
	end
    else if RISFREE[S1RTA] or USES_RTA(OPND1) or USES_RTA(OPND2) then
	begin
	if not RISFREE[S1RTA] then FREERG_S (S1RTA);
	if DOUBRES then ALLOCRP(S1RTA) else ALLOCRG(S1RTA);
	R := S1RTA;
	EMITTOP (OPCD, 2, OPND1, OPND2);
	end
    else if RISFREE[S1RTB] or USES_RTB(OPND1) or USES_RTB(OPND2) then
	begin
	if not RISFREE[S1RTB] then FREERG_S (S1RTB);
	if DOUBRES then ALLOCRP(S1RTB) else ALLOCRG(S1RTB);
	RTBUSER := STE;
	RTBDOUB := DOUBRES;
	R := S1RTB;
	EMITTOP (OPCD, 3, OPND1, OPND2);
	end
    else
	begin  (*if all else fails, emit a move*)
	if DOUB1 or DOUBRES then FINDRP else FINDRG;
	REG_OPERAND (OPNDR, NXTRG);
	if DOUB1 then MOVEOP:=XMOV_D_D else MOVEOP:=XMOV_S_S;
	EMITXOP (MOVEOP, OPNDR, OPND1);
	R := NXTRG;
	EMITTOP (OPCD, 0, OPNDR, OPND2);
	if DOUB1 and not DOUBRES then
	    begin
	    FREERG_S (R);
	    ALLOCRG (R);
	    end;
	end
    end (*ALLOC_AND_EMIT_TOP*);
(** DATUM_PROCESSOR_CLASS:	LENGTH_TO_INTOPNDTYPE REG_DATUM COERCE_DATUM CVT_INT_DATUM COERCE_INT_DATUM COERCE_TWO_DATUMS DAT_IS_REG DAT_ISFREE_REG DAT_IS_T_REG DAT_IS_FILADR LOADSTKENTRY LOADSTACKEXCEPT BJUMP_TO_BINTVAL INCREMENT_DATUM XCHANGE_STKENTS **)
(**)

procedure GET_OPERAND (var OPND :  OPERAND;  STE :  STKINX);
    forward;


procedure FIT_IN_OPERAND (var TOO_COMPLICATED :  boolean;
			var OPND :  OPERAND;  STE : STKINX);
    forward;


procedure MOVE_QUANTITY (var DEST :  OPERAND; STE :  STKINX);
    forward;


procedure SIMPLIFY (STE :  STKINX);
    forward;


procedure ADD_SUB_SINGLE (var DEST :  S1REGISTER;  ADDOP :  S1OPCODE;
			  var OPND1, OPND2 :  OPERAND; STE :  STKINX);
    forward;


function LENGTH_TO_INTOPNDTYPE(LEN :  DTYPE_LENGTH) :  OPNDTYPE;
    (*Return the integer type whose precision corresponds to
	the length LEN in bits -- als/peg 19jul79.*)

    begin
    if LEN mod QWBITS <> 0 then ASSERTFAIL('LENGTH_TO001');
    if LEN = DWBITS then
	LENGTH_TO_INTOPNDTYPE := TYPUI
    else if LEN = WORDBITS then
	LENGTH_TO_INTOPNDTYPE := TYPUJ
    else if LEN = HWBITS then
	LENGTH_TO_INTOPNDTYPE := TYPH
    else if LEN = QWBITS then
	LENGTH_TO_INTOPNDTYPE := TYPQ
    else ASSERTFAIL('LENGTH_TO002');
    end (*LENGTH_TO_INTOPNDTYPE*);


procedure REG_DATUM (STE :  STKINX;  RESCODESTART :  AN_INSTREC; 
			RESTYPE :  OPNDTYPE;  RESREG :	S1REGISTER); (*DATASTRCH*)
    (*Build a datum in STK[STE] describing a quantity stored in a
	given register, with a given CODESTART and DTYPE.*)
    (* als/peg 03jul79 *)

    var	R :  S1REGISTER;

    begin
    STK[STE] := ZERODATUM;
    with STK[STE] do
	begin
	CODESTART := RESCODESTART;
	DTYPE := RESTYPE;
	if RPWORD[RESREG] = R1STOFPAIR then
	    DLENGTH := 2*WORDBITS
	else if RPWORD[RESREG] = R1STOFBLOCK then
	    begin
	    R := RESREG + 1;
	    DLENGTH := WORDBITS;
	    while RPWORD[R] = RINBLOCK do
		begin
		DLENGTH := DLENGTH + WORDBITS;
		R := R + 1;
		end;
	    end
	else DLENGTH := WORDBITS;
	MTYPE := R_SPACE;
	NVPAS := 1;
	VPA1.VPA.WHICH := RGS;
	VPA1.VPA.RGADR := RESREG;
	end;
    end (*REG_DATUM*);



procedure COERCE_DATUM(STE :  STKINX; RTYPE :  OPNDTYPE);
    (*Perform a type coercion of the datum STE to type RTYPE*)

    var OPND, OPNDR :  OPERAND;
	OPRRG :  S1REGISTER;
	MOVEOP :  S1OPCODE;

    begin
    with STK[STE] do
	if DTYPE <> RTYPE then
	    begin
	    MOVEOP := MOV_X_Y[RTYPE,DTYPE];
	    if MOVEOP = XILLEGAL then
		ERROR(WINVALID_TYPE_COERCION);
	    if IS_CONSTANT(STE) then
		if (DTYPE = TYPUN) and (RTYPE = TYPUA) then
		    (*leave TYPUN alone, it's already TYPUA (sort of)*)
		else if IS_INTEGER[RTYPE] and IS_INTEGER[DTYPE] then
		    if (RTYPE in [TYPUI, TYPUK])
		      or (DTYPE in [TYPUI, TYPUK]) then
			ERROR(WNOT_IMPLEMENTED)
		    else
			DTYPE := RTYPE
		else if IS_INTEGER[RTYPE] and IS_REAL[DTYPE] then
		    if RTYPE = TYPUQ then ERROR(WNOT_IMPLEMENTED)
		    else
			begin
			FPA.WHICH := MEM;
			FPA.MEMADR.DSPLMT := round(RCNST);
			DTYPE := RTYPE
			end
		else if IS_REAL[RTYPE] and IS_INTEGER[DTYPE] then
		    if (RTYPE = TYPUQ) or (DTYPE in [TYPUI, TYPUK]) then
			ERROR(WNOT_IMPLEMENTED)
		    else
			begin
			RCNST := FPA.MEMADR.DSPLMT;
			FPA := ZEROFPA;
			DTYPE := RTYPE;
			end
		else ERROR(WINVALID_TYPE_COERCION)
		    
	    else if DTYPE = TYPUM then
		begin
		if not (RTYPE = TYPUA) then ASSERTFAIL('COERCE_DA001');
		repeat SIMPLIFY(STE) until DTYPE = TYPUA;
		end
	    else
		begin
		GET_OPERAND(OPND,STE);
(*pn 27sep79...*)  if RTYPE = TYPUS then
			FINDRGBLOCK(S1SETREP_SIZE)
(*...pn 27sep79*)  else if IS_DOUBLE[RTYPE] then FINDRP else FINDRG;
		OPRRG := NXTRG;
		REG_OPERAND(OPNDR, OPRRG);
		EMITXOP(MOVEOP, OPNDR, OPND);
		FREEDATUMREGS(STE);
		REG_DATUM(STE, CODESTART, RTYPE, OPRRG);
		end;
	    end;
    end (*COERCE_DATUM*);


procedure CVT_INT_DATUM(STE :  STKINX);
    (*The datum in the stack at STE is TYPUJ or TYPUL.  If it is of qword
	or hword length, convert it to TYPQ or TYPH -- als/peg 20jul79.*)

    begin
    with STK[STE] do
	begin
	if not (DTYPE in [TYPUJ, TYPUL]) then ASSERTFAIL('CVT_INT_D001');
	if DLENGTH <> WORDBITS then
	    DTYPE := LENGTH_TO_INTOPNDTYPE(DLENGTH);
	end (*with*);
    end (*CVT_INT_DATUM*);


procedure COERCE_INT_DATUM(STE :  STKINX);
    (*The datum in the stack at STE is TYPUJ or TYPUL, but may be
	of qword or hword length.  Coerce it to sword length --
	als/peg 20jul79.*)

    var RESTYPE :  OPNDTYPE;

    begin
    with STK[STE] do
	begin
	if not (DTYPE in [TYPUJ, TYPUL]) then ASSERTFAIL('COERCE_IN001');
	RESTYPE := DTYPE;
	if DLENGTH <> WORDBITS then
	    begin
	    DTYPE := LENGTH_TO_INTOPNDTYPE(DLENGTH);
	    COERCE_DATUM(STE, RESTYPE);
	    end;
	end (*with*);
    end (*COERCE_INT_DATUM*);


procedure COERCE_TWO_DATUMS(var IS_OKTYPE :
					 OPNDTYPE_TO_BOOLEAN_ARRAY);
	    (*Instead of IS_OKTYPE, could possibly pass a set
	     of legal result types.*)
    (*Take the top two datums on the stack, verify that they represent
     acceptable types, and emit code to coerce them both to the same
     result type.*)

    var TYPE1, TYPE2, RTYPE :  OPNDTYPE;

    begin
    TYPE1 := STK[TOP-1].DTYPE;
    TYPE2 := STK[TOP].DTYPE;
    if not IS_OKTYPE[TYPE1] or not IS_OKTYPE[TYPE2] then
	ERROR(WBINARY_OPND_TYPE_CONFLICT);
    RTYPE := ARITH_RESULT_TYPE[TYPE1,TYPE2];
    if RTYPE = ILLARITH then
	ERROR (WBINARY_OPND_TYPE_CONFLICT);
    COERCE_DATUM(TOP-1,RTYPE);
    COERCE_DATUM(TOP,RTYPE)
    end (*COERCE_TWO_DATUMS*);


function DAT_IS_REG (STE :  STKINX) :  boolean;
    (*Return true iff datum specifies a quantity contained in a
	register.*)

    begin
    with STK[STE] do
	DAT_IS_REG := (FINALIND = IND0) and
			 (FPA = ZEROFPA) and
			 (DTYPE <> TYPUM) and
			 ( (DTYPE <> TYPUB)
			    or (BREPRES = BINTVAL) ) and
			 (NVPAS = 1) and
			 (VPA1.VPAIND = IND1) and
			 (VPA1.VSHIFT = 0) and
			 (VPA1.VPA.WHICH = RGS);
    end (*DAT_IS_REG*);


function DAT_ISFREE_REG (STE :  STKINX) :  boolean;		(*EJG 17JAN79*)
								(*PEG 18FEB79*)
    (*Return true iff datum specifies a quantity contained in a	
	register which is currently free.*)

    begin
    DAT_ISFREE_REG := false;
    with STK[STE] do
	if (FINALIND = IND0) and
	    (FPA = ZEROFPA) and
	    (DTYPE <> TYPUM) and
	    ( (DTYPE <> TYPUB)
	       or (BREPRES = BINTVAL) ) and
	    (NVPAS = 1) and
	    (VPA1.VPAIND = IND1) and
	    (VPA1.VSHIFT = 0) and
	    (VPA1.VPA.WHICH = RGS)
	then if RISFREE[VPA1.VPA.RGADR] then DAT_ISFREE_REG := true;
    end (*DAT_ISFREE_REG*);


function DAT_IS_T_REG (STE :	STKINX) :  boolean;
    (*Return true iff datum specifies a quantity contained in a
	temporary register.*)

    begin
    with STK[STE] do
	DAT_IS_T_REG := (FINALIND = IND0) and
			   (FPA = ZEROFPA) and
			   (DTYPE <> TYPUM) and
			   ( (DTYPE <> TYPUB)
			      or (BREPRES = BINTVAL) ) and
			   (NVPAS = 1) and
			   (VPA1.VPAIND = IND1) and
			   (VPA1.VSHIFT = 0) and
			   (VPA1.VPA.WHICH = RGS) and
			(*finally:*)
			  ((VPA1.VPA.RGADR = S1RTA) or
			   (VPA1.VPA.RGADR = S1RTB) or
			   (MINTMPS1REG <= VPA1.VPA.RGADR) and
			   (VPA1.VPA.RGADR <= MAXTMPS1REG));
    end (*DAT_IS_T_REG*);


function DAT_IS_FILADR (STE :  STKINX) :  boolean;
    (*Return true iff datum specifies the quantity at U-Code
	location <1,LCIOFILADR>. *)

    begin
    with STK[STE] do
	DAT_IS_FILADR :=
	    (DTYPE = TYPUA) and
	    (FINALIND = IND0) and
	    (FPA = ZEROFPA) and
	    (NVPAS = 1) and
	    (VPA1.VSHIFT = 0) and
	    (VPA1.VPAIND = IND1) and
	    (VPA1.VPA.WHICH = MEM) and
	    (VPA1.VPA.MEMADR.LVL = 1) and
	    (VPA1.VPA.MEMADR.DSPLMT
		     = LCIOFILADR + FILE_OFFSET);
    end (*DAT_IS_FILADR*);


procedure XCHANGE_STKENTS (STE1, STE2 :  STKINX);	(*peg 15MAY79*)
    (*Exchange the datum at STK[STE1] with that at STK[STE2].*)

    var	T_DATUM :  DATUM;

    begin
    T_DATUM := STK[STE1];
    STK[STE1] := STK[STE2];
    STK[STE2] := T_DATUM;
    end (*XCHANGE_STKENTS*);
    

procedure BJUMP_TO_BINTVAL (STE :  STKINX);
    (*Convert the datum, which is a boolean in bjump form, into
	bintval form.*)
	
    (*This procedure probably could be done more easily simply by
    loading a zero, then executing a conditional-skip tree which
    may load a one at the end or may skip the load.  LCW*)

    var LOADFIRST :  boolean;
	FALLTHRUJUMP :	AN_INSTREC;				(*DATASTRCH*)
	OPNDR, OPND2 :	OPERAND;
	TLOAD, FLOAD, SKIPLOC, CONTINUE :  AN_INSTREC;		(*DATASTRCH*)
	P, NEXT : AN_INSTREC;					(*DATASTRCH*)

    begin
    with STK[STE] do
	begin
	if not ((DTYPE=TYPUB) and (BREPRES=BJUMP)) then
            ASSERTFAIL('BJUMP_TO_001');
	FALLTHRUJUMP := BFALLTHRUSKIPLOC↑.NEXTPTR;		(*DATASTRCH*)
	if BTRUELIST.NWORDS < BFALSELIST.NWORDS then
	    LOADFIRST := (true)
	else LOADFIRST := (false);
	P := BFALLTHRUSKIPLOC;  				(*DATASTRCH*)
	DELETE_INSTR(FALLTHRUJUMP);				(*DATASTRCH*)
	    (*remove the fall-through jump*)
	if LOADFIRST <> BJUMPON then
	    begin
	    BFALLTHRUSKIPLOC↑.OPCODE := INVERSE_SKIP[BFALLTHRUSKIPLOC↑.OPCODE];(*DATASTRCH*)
	    BJUMPON := not BJUMPON;
	    end;
	REG_OPERAND (OPNDR, VPA1.VPA.RGADR);
	    (*Use the reg allocated to the bjump when created.*)
	if LOADFIRST = (true) then
	    begin  (*load true first*)
	    IMM_OPERAND (OPND2, 1);
	    INSERTXOP (P, XMOV_Q_Q, OPNDR, OPND2);
	    TLOAD := P↑.NEXTPTR;
	    P := TLOAD;
	    INSERTSOP (P, XSKP_EQL_Q, 0, ZERO_OP, ZERO_OP, nil);
	    SKIPLOC := P↑.NEXTPTR;
	    INSERTXOP (SKIPLOC, XMOV_Q_Q, OPNDR, ZERO_OP);	(*DATASTRCH*)
	    FLOAD := SKIPLOC↑.NEXTPTR;				(*DATASTRCH*)
	    FIXSOP (BFALLTHRUSKIPLOC, FLOAD);
	    CONTINUE := FLOAD↑.NEXTPTR;				(*DATASTRCH*)
	    if CONTINUE <> nil then FIXSOP (SKIPLOC, CONTINUE)
	    else FIXSOP (SKIPLOC, NEWINSTREC);
	    end (*load true first*)
	else
	    begin  (*load false first*)
	    INSERTXOP (P, XMOV_Q_Q, OPNDR, ZERO_OP);
	    FLOAD := P↑.NEXTPTR;
	    P := FLOAD;
	    INSERTSOP (P, XSKP_EQL_Q, 0, ZERO_OP, ZERO_OP, nil);
	    SKIPLOC := P↑.NEXTPTR;
	    IMM_OPERAND (OPND2, 1);
	    INSERTXOP (SKIPLOC, XMOV_Q_Q, OPNDR, OPND2);	(*DATASTRCH*)
	    TLOAD := SKIPLOC↑.NEXTPTR;				(*DATASTRCH*)
	    FIXSOP (BFALLTHRUSKIPLOC, TLOAD);
	    CONTINUE := TLOAD↑.NEXTPTR;				(*DATASTRCH*)
	    if CONTINUE <> nil then FIXSOP (SKIPLOC, CONTINUE)
	    else FIXSOP (SKIPLOC, NEWINSTREC);
	    end (*load false first*);

	P := BTRUELIST.FIRST;
	while P <> nil do
	    begin
            NEXT := P↑.DESTPTR;				(*DATASTRCH*)
	    FIXJOP (P, TLOAD);
	    P := NEXT;
	    end;
	P := BFALSELIST.FIRST;
	while P <> nil do
	    begin
	    NEXT := P↑.DESTPTR;				(*DATASTRCH*)
	    FIXJOP (P, FLOAD);
	    P := NEXT;
	    end;
	REG_DATUM (STE, CODESTART, TYPUB, VPA1.VPA.RGADR);
	BREPRES := BINTVAL;
	end (*with STK[STE] do*)
    end (*BJUMP_TO_BINTVAL*);



procedure LOADSTKENTRY(STE :  STKINX);
    (*Force an actual load of the item at STK[STE] -- als/peg 27jul79.*)

    var OPND, OPNDR :  OPERAND;
	R :  S1REGISTER;

    begin
    with STK[STE] do
	if (NVPAS>0) and
	  not DAT_IS_FILADR(STE) and
	  not DAT_IS_T_REG(STE) and
	  not DAT_ISFREE_REG(STE) then
	    if (DTYPE = TYPUB) and (BREPRES = BJUMP) then
		BJUMP_TO_BINTVAL(STE)
	    else
		begin
		GET_OPERAND(OPND, STE);
		if not DAT_IS_T_REG(STE) then
		    begin  (*generate a MOV*)
(*peg 27sep79...*)  if DTYPE = TYPUS then
			FINDRGBLOCK(S1SETREP_SIZE)
(*...peg 27sep79*)  else if IS_DOUBLE[DTYPE] then FINDRP else FINDRG;
		    R := NXTRG;
		    REG_OPERAND (OPNDR, R);
		    MOVE_QUANTITY (OPNDR, STE);
		    FREEDATUMREGS (STE);
		    REG_DATUM (STE, CODESTART, DTYPE, R);
		    end (*generate a MOV*);
		end;
    end (*LOADSTKENTRY*);


procedure LOADSTACKEXCEPT (BOTEXC, TOPEXC :  STKINX);
    (*In order to prevent possible side effects because of standard
	procedure calls or user procedure calls inside codeforks, we
	call this procedure to load most items on the virtual stack into
	temporary registers.  Exceptions are constants (which are
	completely in virtual form) and bjump booleans (which have no
	storage associated with them that can be changed).  There are
	often stack entries, however, which we don't need or wish to
	load in this way, because they are parameters which are being
	passed or because we are about to throw them away anyway.  The
	range BOTEXC<=STE<=TOPEXC consists of such entries, and items in
	that part of the stack are not loaded.  Any DATUM which is a
	file address is also not loaded. (A kludge so CHECKFILADR
	will be able to tell which DATUMs are file addresses.) Later,
	file addresses will be passed as parameters.*)

    var OPNDR :  OPERAND;
	STE :  STKINX;
	R :  S1REGISTER;

    begin
    for STE := BOT to TOP do
	with STK[STE] do
	    if ((STE<BOTEXC) or (STE>TOPEXC)) and (NVPAS>0) and
	      ((DTYPE<>TYPUB) or (BREPRES=BINTVAL)) and
	      not DAT_IS_FILADR(STE) and
	      not DAT_IS_T_REG(STE) and
	      not DAT_ISFREE_REG(STE) then			(*EJG 17JAN79*)
		begin  (*generate a MOV*)
(*pn 27sep79...*)  if DTYPE = TYPUS then
			FINDRGBLOCK(S1SETREP_SIZE)
(*...pn 27sep79*)  else if IS_DOUBLE[DTYPE] then FINDRP else FINDRG;
		R := NXTRG;
		REG_OPERAND (OPNDR, R);
		MOVE_QUANTITY (OPNDR, STE);
		FREEDATUMREGS (STE);
		REG_DATUM (STE, CODESTART, DTYPE, R);
		end (*generate a MOV*);
    end (*LOADSTACKEXCEPT*);



procedure INCREMENT_DATUM(STE :  STKINX; INCR :  integer);	(*EJG*)
    (*Increment the datum STE by the constant amount INCR*)

    var
	OLDTYPE :  OPNDTYPE;
	OPND1, OPND2 :  OPERAND;
	COMBINABLE, CALCULABLE, RESDBL :  boolean;
	TOOMUCH1 :  boolean;
	DEST :  S1REGISTER;

    begin
    with STK[STE] do
	begin
	if not ((IS_INTEGER[DTYPE])
	        or (DTYPE in [TYPUA, TYPUB, TYPUC, TYPUM])) then
	    ERROR (WNOT_DISCRETE_TYPE);

	if INCR <> 0 then
	    begin
	    OLDTYPE := DTYPE;
	    if DTYPE in [TYPUB, TYPUC] then
		begin
		if (DTYPE = TYPUB) and (BREPRES = BJUMP) then
		    BJUMP_TO_BINTVAL (STE);
		DTYPE := TYPQ;
		end;

	    if not (DTYPE in [TYPUA, TYPUI, TYPUJ, TYPUK, TYPUL, TYPUM]) then
		COERCE_DATUM(STE, TYPUJ);

	    if DTYPE in [TYPUI, TYPUK] then
		    begin
		    GET_OPERAND (OPND1, STE);
		    IMM_OPERAND (OPND2, INCR);
		    ALLOC_AND_EMIT_TOP (DEST, XADD_D, OPND1, OPND2,
					RESDBL, RESDBL, RESDBL, STE);
		    FREEREGSBUTTHESE (STE, [DEST]);
		    REG_DATUM (STE, CODESTART, OLDTYPE, DEST);
		    end (*if IS_INTEGER*)

	    else
		begin  (*TYPUA, TYPUJ, TYPUL, TYPUM*)
		COMBINABLE := false;
		CALCULABLE := false;
		repeat
		    if FINALIND = IND0 then COMBINABLE := true
		    else
			begin
			FIT_IN_OPERAND (TOOMUCH1, OPND1, STE);
			if TOOMUCH1 then
			    SIMPLIFY (STE)
			else
			    CALCULABLE := true;
			end (*not combinable*);
		until COMBINABLE or CALCULABLE;

		if COMBINABLE then
		    FPA.MEMADR.DSPLMT := FPA.MEMADR.DSPLMT + INCR
		else
		    begin  (*calculable*)
		    IMM_OPERAND (OPND2, INCR);
		    ADD_SUB_SINGLE (DEST, XADD_S, OPND1, OPND2, STE);
		    FREEREGSBUTTHESE (STE, [DEST]);
		    REG_DATUM (STE, CODESTART, DTYPE, DEST);
		    end (*calculable*);
		end (*TYPUA, TYPUJ, TYPUM*);
	    end (*if INCR <> 0*);
        end (*with STK[STE]*);
    end (*INCREMENT_DATUM*);

(** DATUM_PROCESSOR_CLASS:	BINTVAL_TO_BJUMP PARMREG_TO_PARMSAVE INC_INDIRECTION TRANSLATE_LVLDSP **)
(**)

procedure BINTVAL_TO_BJUMP (STE :  STKINX);
    (*Convert the datum, which is a boolean in bintval form,
	into bjump form.*)

    var OPND :	OPERAND;
	SKIPLOC :  AN_INSTREC;					(*DATASTRCH*)
	RESCODESTART :	AN_INSTREC;				(*DATASTRCH*)

    begin
    with STK[STE] do
	begin
	if not ((DTYPE=TYPUB) and (BREPRES=BINTVAL)) then
            ASSERTFAIL('BINTVAL_T001');
	GET_OPERAND (OPND, STE);
	LOADSTACKEXCEPT (STE, STE);
	if not RISFREE[S1RTB] and (RTBUSER <> STE) then
	    MOVE_AND_FREE_RTB;
	FREEDATUMREGS (STE);
	SKIPLOC := NEWINSTREC;
	EMITSOP (XSKP_EQL_Q, 0, OPND, ZERO_OP, nil);
	EMITJOP (XJMPA, 0, UNUSED_OP, ZERO_OP, nil);
	FIXSOP (SKIPLOC, NEWINSTREC);
	RESCODESTART := CODESTART;
	STK[STE] := ZERODATUM;
	CODESTART := RESCODESTART;
	DTYPE := TYPUB;
	NVPAS := 1;  (*make it not look like a constant.  Not needed?*)
	FINDRG;
	VPA1.VPA.WHICH := RGS;
	VPA1.VPA.RGADR := NXTRG;
			  (*where it will go if it becomes bintval*)
	BREPRES := BJUMP;
	BTRUELIST := EMPTYJUMPLIST;
	BFALSELIST := EMPTYJUMPLIST;
	BJUMPON := true;
	BFALLTHRUSKIPLOC := SKIPLOC;
	end (*with STK[STE] do*);
    end (*BINTVAL_TO_BJUMP*);


procedure PARMREG_TO_PARMSAVE (STE :  STKINX;  PWORD :	NONNEGINT);
    (*If the datum contains references to parameter registers
	logically preceding (but not including) parameter register
	number 'PWORD', convert those references to the corresponding
	location in the local parameter save area.*)

    var P :  integer;

    begin
    with CURPROCSPEC, STK[STE] do
	if NVPAS >= 1 then if VPA1.VPA.WHICH = RGS then if
	   IS_PARMREG(VPA1.VPA.RGADR) then if
	   S1REG_TO_PRM[VPA1.VPA.RGADR] < PWORD then
	    begin
	    P := S1REG_TO_PRM[VPA1.VPA.RGADR];
	    VPA1.VPA.WHICH := MEM;
	    VPA1.VPA.MEMADR.LVL := CURLVL;
	    VPA1.VPA.MEMADR.DSPLMT := R_OFFSET + P*WORDUNITS;
	    if NVPAS>=2 then if VPA2.VPA.WHICH=RGS then if
	       IS_PARMREG(VPA2.VPA.RGADR) then if
	       S1REG_TO_PRM[VPA2.VPA.RGADR] < PWORD then
		begin
		P := S1REG_TO_PRM[VPA2.VPA.RGADR];
		VPA2.VPA.WHICH := MEM;
		VPA2.VPA.MEMADR.LVL := CURLVL;
		VPA2.VPA.MEMADR.DSPLMT := R_OFFSET + P*WORDUNITS;
		end;
	    end;
    end (*PARMREG_TO_PARMSAVE*);



procedure INC_INDIRECTION(STE :  STKINX; MAXFINALIND :  INDIRECTION);
    (*Increase the indirection on the datum at STK[STE] once
	-- als/peg 19jul79.*)

    begin
    with STK[STE] do
	begin
	while FINALIND > MAXFINALIND do
	    SIMPLIFY (TOP);
	if FPA.WHICH = RGS then ASSERTFAIL('INC_INDIR001');
	if NVPAS = 0 then
	    begin  (*move FPA to VPA*)
	    NVPAS := 1;
	    VPA1.VPAIND := IND1;
	    VPA1.VPA := FPA;
	    FPA := ZEROFPA;
	    end (*move FPA to VPA*)
	else if (NVPAS=1) and (FPA=ZEROFPA) then
	    begin  (*increase indirection on single VPA*)
	    if VPA1.VSHIFT<>0 then
		ERROR (WINDEX_WITHOUT_BASE);
	    if VPA1.VPAIND = IND1 then VPA1.VPAIND := IND2
				  else FINALIND := succ(FINALIND);
	    end (*increase indirection on single VPA*)
	else
	    (*the datum has multiple parts*)
	    FINALIND := succ(FINALIND);
	end (*with STK[STE] do*);
    end (*INC_INDIRECTION*);


procedure TRANSLATE_LVLDSP(var X :  MEMOREG;  MEMAREA :  MEMTYPE);
    (*Translates a U-Code (LVL,DSPLMT) into an S1 (LVL,DSPLMT) or an
     S1REGISTER.*)

    var TMPLVL :  0..MAXLVL;

    begin
    if not (X.WHICH = MEM) then ASSERTFAIL('TRANSL_LV001');
    if not (X.MEMADR.LVL <= CURLVL) then ASSERTFAIL('TRANSL_LV002');
    if not (X.MEMADR.DSPLMT mod QWBITS = 0) then ASSERTFAIL('TRANSL_LV003');
    X.MEMADR.DSPLMT := X.MEMADR.DSPLMT div QWBITS;
    TMPLVL := X.MEMADR.LVL;
    if TMPLVL = 1 then
	if MEMAREA = M_SPACE then
	    if X.MEMADR.DSPLMT < LASTFILBUF then
		X.MEMADR.DSPLMT := X.MEMADR.DSPLMT + FILE_OFFSET
	    else X.MEMADR.DSPLMT := X.MEMADR.DSPLMT - L1FIRSTADDR + M_OFFSET
	else ERROR(WNOT_IMPLEMENTED)

    else if (TMPLVL = CURLVL) and (MEMAREA = R_SPACE)
      and not PREGS_ARCHIVED then
	begin  (*map local parm into its register*)
	X.RGADR := PRM_TO_S1REG[(X.MEMADR.DSPLMT) div WORDUNITS];
	X.WHICH := RGS
	end

    else if MEMAREA in [R_SPACE, M_SPACE] then
	case MEMAREA of
	    R_SPACE :  X.MEMADR.DSPLMT := X.MEMADR.DSPLMT + R_OFFSET;
	    M_SPACE :  X.MEMADR.DSPLMT := X.MEMADR.DSPLMT - FIRSTADDR + M_OFFSET
	end (*case*)

    else
	ERROR(WNOT_IMPLEMENTED);
    end (*TRANSLATE_LVLDSP*);

(** DATUM_PROCESSOR_CLASS:	IS_SIMPLE FITS_SHRT_OFFSET FITS_SHORT_INDEX IS_CONSTANT IS_CNST_PLUS_OPND PUSHTOP POPTOP PUSH_STKFRAME POP_STKFRAME **)
(**)

function IS_SIMPLE (var V :  VPAREC) :	boolean;
    (*Return true iff the VPA specifies an unshifted quantity
	stored in a register.*)

    begin
    IS_SIMPLE := (V.VPAIND=IND1) and (V.VSHIFT=0)
		and (V.VPA.WHICH=RGS);
    end (*IS_SIMPLE*);



function FITS_SHRT_OFFSET (*(DISP :  S1DISP) :  boolean*);
    (*Returns true iff the displacement is such that it
	can be used in a short index.*)

    begin
    FITS_SHRT_OFFSET := (DISP mod WORDUNITS = 0)
		     and (MINSHORTOFFSET <= DISP div WORDUNITS)
		     and (DISP div WORDUNITS <= MAXSHORTOFFSET)
    END (*FITS_SHRT_OFFSET*);



function FITS_SHORT_INDEX (var V :  VPAREC) :  boolean;
    (*Returns true iff the VPA can be inserted as the
	short index of an extended operand.*)

    var D :  INTEGER;

    begin
    if V.VPA.WHICH = RGS then FITS_SHORT_INDEX := true
    else
	begin
	D := V.VPA.MEMADR.DSPLMT div WORDUNITS;
	FITS_SHORT_INDEX := (V.VPAIND = IND1)
		   and (V.VPA.MEMADR.LVL > 0)
		   and (V.VPA.MEMADR.DSPLMT mod WORDUNITS = 0)
		   and (MINSHORTOFFSET <= D)
		   and (D <= MAXSHORTOFFSET)
	end
    end (*FITS_SHORT_INDEX*);



function IS_CONSTANT (*(STE :  STKINX) :  boolean*);
    (*Return true iff datum represents a constant.*)

    begin
    with STK[STE] do
	IS_CONSTANT := (FINALIND = IND0)
		      and (NVPAS = 0)
		      and (FPA.WHICH = MEM)
		      and (DTYPE <> TYPUM)
		      and ( (DTYPE <> TYPUB)
			    or (BREPRES = BINTVAL) )
		      and (FPA.MEMADR.LVL = 0);
    end (*IS_CONSTANT*);



function IS_CNST_PLUS_OPND (STE :  STKINX) :  boolean;
    (*Return true iff datum represents a nonzero constant plus
	other parts which will fit in an operand if the constant
	part is excluded.*)

    begin
    with STK[STE] do
	IS_CNST_PLUS_OPND := (FINALIND = IND0)
		and not (DTYPE in [TYPUB, TYPUM])
		and (FPA.WHICH = MEM)
		and (FPA.MEMADR.DSPLMT <> 0)
		and ( (FPA.MEMADR.LVL=0) and (NVPAS=1)
		      and (VPA1.VSHIFT=0)
		     or (FPA.MEMADR.LVL<>0)
			and (NVPAS=0) );
    end (*IS_CNST_PLUS_OPND*);



procedure PUSHTOP;
    (*Push an undefined datum onto the virtual stack,
	checking for overflow.*)

    begin
    if TOP < MAXSTKINX then TOP := TOP + 1
    else ERROR (WEXPR_TOO_COMPLEX);
    end (*PUSHTOP*);



procedure POPTOP;
    (*Pop the top value from the stack and discard it,
	checking for underflow.*)

    begin
    if TOP >= BOT then TOP := TOP - 1
    else ERROR (WPOP_OF_EMPTY_STACK);
    end (*POPTOP*);


procedure PUSH_STKFRAME;
    (*Push a new stack frame onto the virtual stack -- peg 13jul79.*)

    begin
    if CURFRAME >= MAXFRAME then ASSERTFAIL('PUSH_STKF001');
    STKFRAME[CURFRAME] := BOT;
    CURFRAME := CURFRAME + 1;
    PUSHTOP;  STK[TOP] := ZERODATUM;
    BOT := TOP;
    POPTOP;
    end (*PUSH_STKFRAME*);


procedure POP_STKFRAME;
    (*Pop a stack frame from the virtual stack -- peg 13jul79.*)

    begin
    if CURFRAME <= MINFRAME then ASSERTFAIL('POP_STKFR001');
    CURFRAME := CURFRAME - 1;
    BOT := STKFRAME[CURFRAME];
    end (*POP_STKFRAME*);


(** LITERAL_TABLE_CLASS:	UPD_REALTBL UPD_SETTBL UPD_PROCTBL **)
(**)

procedure UPD_REALTBL (var DISP :  S1DISP; RVAL :  real);
    (*Add the real to the real table if not already there.  Return
	its table displacement in DISP.*)

    var FOUND :  boolean;
	PTR :  A_CODEREC;
	W :  S1WORD;

    begin
    FOUND := false;
    DISP := 0;
    PTR := REALTBL.FIRST;
    REAL_TO_S1WORD (W, RVAL);
    while not FOUND and (PTR <> nil) do
	if (PTR↑.CODEWORD = W) then
	    FOUND := true
	else
	    begin
	    PTR := PTR↑.NEXTPTR↑.NEXTPTR;
	    DISP := DISP + WORDUNITS;
	    end;

    if not FOUND then
	begin
	EMIT_S1WORD (REALTBL, W);
	end;
    end (*UPD_REALTBL*);



procedure UPD_SETTBL (var DISP :  S1DISP;  SVAL :  SETREP);
    (*Add the entire set to the set table if not already there.*)

    var FOUND :  boolean;
	PTR :  A_CODEREC;		(*setch...*)
	CNT :  0..S1SETREP_SIZE;
	INDEX :  S1SETREP_INDEX;
	S1SET :  S1SETREP;		(*...setch*)

    begin
    FOUND := false;
    DISP := 0;
    PTR := SETTBL.FIRST;
    SETREP_TO_S1WORDS (S1SET, SVAL);				(*setch*)
    while not FOUND and (PTR <> nil) do
	begin							(*setch...*)
	CNT := 0;
	for INDEX := 0 to S1SETREP_MAX do
	    begin
	    if PTR↑.CODEWORD = S1SET[INDEX] then CNT := CNT + 1;
	    PTR := PTR↑.NEXTPTR;
	    end;

	if CNT = S1SETREP_SIZE then FOUND := true
	else DISP := DISP + S1SETREP_SIZE*WORDUNITS;
	end (*while*);

    if not FOUND then
	for INDEX := 0 to S1SETREP_MAX do
	    EMIT_S1WORD(SETTBL, S1SET[INDEX]);			(*...setch*)

    end (*UPD_SETTBL*);



procedure UPD_PROCTBL (var FIXPTR :  A_PROCENT; var PID :  ALFA);
    (*Add the name in PID to the proc table if not already there and
	return a pointer to the entry for fixup purposes.*)

    var PTR :  A_PROCENT;

    begin
    if PROCTBL.FIRST = nil then
	begin
	new (PROCTBL.FIRST);
	with PROCTBL.FIRST↑ do
	    begin
	    NAME := PID;   FIXLIST := EMPTYOPNDXWORDFIXLIST;   NEXTPTR := nil;
	    end;						(*DATASTRCH*)
	PROCTBL.NPROCS := 1;
	FIXPTR := PROCTBL.FIRST;
	end
    else
	begin	(*non-empty table*)
	PTR := PROCTBL.FIRST;
	while (PTR↑.NEXTPTR <> nil) and (PTR↑.NAME <> PID) do
	    PTR := PTR↑.NEXTPTR;
	if PTR↑.NAME = PID then FIXPTR := PTR
	else
	    begin   (*add at end*)
	    new (PTR↑.NEXTPTR);
	    with PTR↑.NEXTPTR↑ do
		begin
		NAME := PID;
		FIXLIST := EMPTYOPNDXWORDFIXLIST;			(*DATASTRCH*)
		NEXTPTR := nil;
		end;
	    PROCTBL.NPROCS := PROCTBL.NPROCS + 1;
	    FIXPTR := PTR↑.NEXTPTR;
	    end (*add at end*);
	end (*non-empty table*);
    end (*UPD_PROCTBL*);

(** LITERAL_TABLE_CLASS:	UPD_LBLTBL UPD_BOUNDTBL **)
(**)

procedure UPD_LBLTBL (*(var LPTR :  A_LBLHASHENT; LNUM :  LBL_INDEX;
		      LCLASS :	LINTVAL_OR_LINSTPTR)*);		(*DATADTRCH*)
    (*Add an entry for this label to the label hash table if one is not
	already there.	Return in LPTR a pointer to the entry.*)

    var H :  RNG_0_LBLHTSIZEM1;
	PTR :  A_LBLHASHENT;
	FOUND :  boolean;

    begin
    H := LABELHASH (LNUM);
    PTR := LBLHASHTAB[H];
    FOUND := false;
    while not FOUND and (PTR <> nil) do
	if PTR↑.LBLNUM = LNUM then  FOUND := true
	else PTR := PTR↑.NEXTPTR;

    if FOUND then LPTR := PTR
    else
	begin  (*add to front*)
	new (PTR);
	PTR↑.NEXTPTR := LBLHASHTAB[H];
	LBLHASHTAB[H] := PTR;
	PTR↑.LBLNUM := LNUM;
	PTR↑.DEFINED := false;
	case LCLASS of
	    LINTVAL : PTR↑.CLIST := EMPTYOPND2FIXLIST;		(*DATASTRCH*)
	    LINSTPTR :
		begin
		PTR↑.JLIST := EMPTYJUMPLIST;
		PTR↑.JUMPTABLELABEL := false
		end
	end (*case*);
	LPTR := PTR;
	end (*add to front*);
    end (*UPD_LBLTBL*);



procedure UPD_BOUNDTBL (var DISP :  S1DISP; LOW, HI :  integer;
						BNDTYP :  OPNDTYPE);
    (*Add the bound triple to the bound table if not already there.
	Return its table displacement in DISP.*)

    var FOUND :  boolean;
	PTR : A_CODEREC;
	W1, W2, W3 :  S1WORD;

    begin
    INTEGER_TO_S1WORD (W1, LOW);
    INTEGER_TO_S1WORD (W2, HI);
    W3 := ZEROS1WORD;
    PUTFIELD (W3, BNDTYP_START, BNDTYP_LEN, ord(TYPECODE[BNDTYP]) );
    PTR := BOUNDTBL.FIRST;
    DISP := 0;
    FOUND := false;
    while not FOUND and (PTR <> nil) do
	if (PTR↑.CODEWORD = W1) and (PTR↑.NEXTPTR↑.CODEWORD = W2) and
	   (PTR↑.NEXTPTR↑.NEXTPTR↑.CODEWORD = W3) then
	    FOUND := true
	else
	    begin
	    PTR := PTR↑.NEXTPTR↑.NEXTPTR↑.NEXTPTR;
	    DISP := DISP + 3*WORDUNITS;
	    end;

    if not FOUND then
	begin
	EMIT_S1WORD (BOUNDTBL, W1);
	EMIT_S1WORD (BOUNDTBL, W2);
	EMIT_S1WORD (BOUNDTBL, W3);
	end;
    end (*UPD_BOUNDTBL*);
(** GET_OPERAND_CLASS:		INSERT_SHORT_VPA VPA_OPERAND_NOSHIFT FIT_IN_OPERAND **)
(**)

procedure INSERT_SHORT_VPA (var OPND :	OPERAND;
			     var V :  VPAREC);
    (*Insert the VPA into the operand as a short index,
	including shift, without changing the rest of
	the operand.*)

    begin
    if not (FITS_SHORT_INDEX(V) and (OPND.X = 1) ) then
        ASSERTFAIL('INS_SH_VP001');
    if V.VPA.WHICH = RGS then
	begin
	if V.VPAIND = IND1 then
	    begin
	    OPND.REG := 0;   OPND.F := V.VPA.RGADR
	    end
	else
	    begin
	    OPND.REG := V.VPA.RGADR;   OPND.F := 0
	    end
	end (*register*)
    else
	begin (*short mem*)
	OPND.REG := LVL_TO_S1REG [V.VPA.MEMADR.LVL];
	OPND.F := V.VPA.MEMADR.DSPLMT div WORDUNITS
	end (*short mem*);

    OPND.XW.S := V.VSHIFT

    end (*INSERT_SHORT_VPA*);



procedure VPA_OPERAND_NOSHIFT(var OPND :  OPERAND; var V :  VPAREC);
    (*Construct an operand specifying the VPA, including indirection
     but not including shift.  Operand may be short or extended.*)

    begin
    if V.VPA.WHICH = RGS then
	begin
	OPND := EMPTY_OP;
	OPND.X := 0;
	if V.VPAIND = IND1 then
	    begin
	    OPND.REG := 0;   OPND.F := V.VPA.RGADR
	    end
	else
	    begin
	    OPND.REG := V.VPA.RGADR;   OPND.F := 0
	    end
	end (*register*)

    else if FITS_SHRT_OFFSET(V.VPA.MEMADR.DSPLMT)
	    and (V.VPA.MEMADR.LVL > 0) then
	begin
	if V.VPAIND = IND2 then
	    ADDR_OPERAND (OPND, 0)
	else
	    begin
	    OPND := EMPTY_OP;
	    OPND.X := 0
	    end;
	OPND.REG := LVL_TO_S1REG [V.VPA.MEMADR.LVL];
	OPND.F := V.VPA.MEMADR.DSPLMT div WORDUNITS
	end (*short offset*)

    else
	begin (*extended address*)
	if V.VPA.MEMADR.LVL = 0 then
	    ADDR_OPERAND (OPND, V.VPA.MEMADR.DSPLMT)
	else
	    XTNDED_REGDISP_OPERAND (OPND,
			 LVL_TO_S1REG [V.VPA.MEMADR.LVL],
			 V.VPA.MEMADR.DSPLMT);
	if V.VPAIND = IND2 then OPND.XW.I := 1
	end (*extended address*)

    end (*VPA_OPERAND_NOSHIFT*);


procedure FIT_IN_OPERAND (*(var TOO_COMPLICATED :  boolean;
			var OPND :  OPERAND;  STE : STKINX)*);
    (*Build an operand accessing the quantity described by the datum if
	this is possible without emitting any code.  Return
	TOO_COMPLICATED = true if this was impossible, false
	otherwise.*)

    begin
    TOO_COMPLICATED := false;

    with STK[STE] do
	begin
	if not (FPA.WHICH = MEM) then ASSERTFAIL('FIT_IN_OP001');
	if DTYPE = TYPUM then TOO_COMPLICATED := true
	else if IS_CONSTANT(STE) then
	    begin
	    if not (FINALIND = IND0) then ASSERTFAIL('FIT_IN_OP002');
	    if DTYPE in [TYPUJ,TYPUL,TYPUB,TYPUC] then
		IMM_OPERAND (OPND, FPA.MEMADR.DSPLMT)
	    else if DTYPE in [TYPUI, TYPUK] then
		begin
		ERROR(WNOT_IMPLEMENTED);
	      %	XTNDED_IMM_OPERAND (OPND, FPA.MEMADR.DSPLMT);
		OPND.F := 1;  (*integer sign extend*) \
		end
	    else if DTYPE = TYPUA then
		begin
		if (FPA.MEMADR.DSPLMT < 0) or
		   (FPA.MEMADR.DSPLMT > MAXS1ADDR) then
		    ERROR (WADDR_OUT_OF_RANGE);
		IMM_OPERAND (OPND, FPA.MEMADR.DSPLMT)
		end (*TYPUA*)
	    else if DTYPE = TYPUQ then
		ERROR(WNOT_IMPLEMENTED)
	    else if DTYPE = TYPUR then
		REAL_IMM_OPERAND (OPND, RCNST)                  (*LCW*)
	    else if DTYPE = TYPUS then
		begin
		XTNDED_REGDISP_OPERAND
			       (OPND, S1RPC, 0);
		OPND.FIXUP := SETFIX;
(*setch*)           UPD_SETTBL (OPND.XW.DISP, SCNST);
		end (*TYPUS*)
	    else if DTYPE = TYPUN then
		IMM_OPERAND (OPND, NILVAL)
	    else if not (false) then ASSERTFAIL('FIT_IN_OP003');
	    end (*constant*)

	else if FINALIND = IND0 then
	    case NVPAS of

		(*NVPAS = *) 0:
		if FPA.MEMADR.DSPLMT = 0 then
		    REG_OPERAND (OPND,
			   LVL_TO_S1REG[FPA.MEMADR.LVL])
		else TOO_COMPLICATED := true;

		(*NVPAS = *) 1:
		if (VPA1.VSHIFT=0) and (FPA=ZEROFPA) then
		    VPA_OPERAND_NOSHIFT (OPND, VPA1)
		else TOO_COMPLICATED := true;

		(*NVPAS = *) 2:
		TOO_COMPLICATED := true;

		end (*case NVPAS of*)

	else
	    begin  (*FINALIND > IND0*)
	    if not ( NVPAS > 0) then ASSERTFAIL('FIT_IN_OP004');

	    if (FPA.MEMADR.LVL=0) and
	       (NVPAS=1) and IS_SIMPLE(VPA1) then
		begin (*non-level register and displacement*)
		if FINALIND = IND1 then
		    REGDISP_OPERAND (OPND, VPA1.VPA.RGADR,
				     FPA.MEMADR.DSPLMT)
		else if FITS_SHRT_OFFSET(FPA.MEMADR.DSPLMT) then
		    begin
		    ADDR_OPERAND (OPND, 0);
		    OPND.REG := VPA1.VPA.RGADR;
		    OPND.F := FPA.MEMADR.DSPLMT div WORDUNITS
		    end
		else
		    begin
		    XTNDED_REGDISP_OPERAND (OPND,
			  VPA1.VPA.RGADR, FPA.MEMADR.DSPLMT);
		    OPND.XW.I := 1
		    end
		end (*non-level register and displacement*)

	    else
		begin (*more complicated*)
		if NVPAS = 1 then

		    (*NVPAS = 1*)
		    begin
		    if not FITS_SHORT_INDEX(VPA1) then
			TOO_COMPLICATED := true
		    else
			begin
			if FPA.MEMADR.LVL > 0 then
			    XTNDED_REGDISP_OPERAND (OPND,
					LVL_TO_S1REG [FPA.MEMADR.LVL],
					FPA.MEMADR.DSPLMT)
			else
			    ADDR_OPERAND (OPND, FPA.MEMADR.DSPLMT);
			INSERT_SHORT_VPA (OPND, VPA1);
			end
		    end (*NVPAS = 1*)

		else

		    (*NVPAS = 2*)
		    if FPA.MEMADR.LVL > 0 then
			TOO_COMPLICATED := true
		    else if IS_SIMPLE(VPA2) and
			       FITS_SHORT_INDEX(VPA1) then
			begin
			XTNDED_REGDISP_OPERAND (OPND,
				  VPA2.VPA.RGADR, FPA.MEMADR.DSPLMT);
			INSERT_SHORT_VPA (OPND, VPA1)
			end
		    else if IS_SIMPLE(VPA1) and
			       FITS_SHORT_INDEX(VPA2) then
			begin
			XTNDED_REGDISP_OPERAND (OPND,
				  VPA1.VPA.RGADR, FPA.MEMADR.DSPLMT);
			INSERT_SHORT_VPA (OPND, VPA2)
			end
		    else
			TOO_COMPLICATED := true;

		if FINALIND = IND2 then OPND.XW.I := 1;
		end (*more complicated*)
	    end (*FINALIND > IND0*);

	end (*with STK[STE] do*);

    end (*FIT_IN_OPERAND*);

(** GET_OPERAND_CLASS:		FIT_ADDRESS_IN_OPERAND **)
(**)

procedure FIT_ADDRESS_IN_OPERAND (var TOO_COMPLICATED :  boolean;
				var OPND :  OPERAND;  STE : STKINX);
    (*Build an operand accessing the location whose address is the
	quantity (of type address) described by the datum, if this is
	possible without emitting any code.  Return TOO_COMPLICATED =
	true if this was impossible, false otherwise.*)

    begin
    TOO_COMPLICATED := false;
    with STK[STE] do
	begin
	if (DTYPE=TYPUM) or (FINALIND>IND1) then
	    TOO_COMPLICATED := true
	else

	    case NVPAS of

		(*NVPAS = *) 0:
		begin
		if not ( FINALIND = IND0) then ASSERTFAIL('FIT_ADDR 001');
		if FPA.WHICH = RGS then
		    REG_OPERAND (OPND, FPA.RGADR)
		else if FPA.MEMADR.LVL = 0 then
		    ADDR_OPERAND (OPND, FPA.MEMADR.DSPLMT)
		else
		    REGDISP_OPERAND (OPND,
			       LVL_TO_S1REG [FPA.MEMADR.LVL],
			       FPA.MEMADR.DSPLMT)
		end (*NVPAS = 0*);

		(*NVPAS = *) 1:
		begin
		if (FPA.MEMADR.LVL = 0) and IS_SIMPLE(VPA1) then
		    begin  (*non-level register and displacement*)
		    if FINALIND = IND0 then
			REGDISP_OPERAND (OPND, VPA1.VPA.RGADR,
					 FPA.MEMADR.DSPLMT)
		    else if FITS_SHRT_OFFSET(FPA.MEMADR.DSPLMT) then
			begin
			ADDR_OPERAND (OPND, 0);
			OPND.REG := VPA1.VPA.RGADR;
			OPND.F := FPA.MEMADR.DSPLMT div WORDUNITS;
			end
		    else
			begin
			XTNDED_REGDISP_OPERAND (OPND,
			       VPA1.VPA.RGADR, FPA.MEMADR.DSPLMT);
			OPND.XW.I := 1;
			end;
		    end (*non-level register and displacement*)
		else if FITS_SHORT_INDEX(VPA1) then
		    begin
		    if FPA.MEMADR.LVL = 0 then
			ADDR_OPERAND (OPND, FPA.MEMADR.DSPLMT)
		    else
			XTNDED_REGDISP_OPERAND (OPND,
				    LVL_TO_S1REG [FPA.MEMADR.LVL],
				    FPA.MEMADR.DSPLMT);
		    INSERT_SHORT_VPA (OPND, VPA1);
		    if FINALIND = IND1 then OPND.XW.I := 1
		    end
		else if (FINALIND=IND0) and (FPA=ZEROFPA) and
		   (VPA1.VSHIFT=0) and (VPA1.VPAIND=IND1) then
		    begin
		    VPA_OPERAND_NOSHIFT (OPND, VPA1);
		    if not ( OPND.X = 1) then ASSERTFAIL('FIT_ADDR 002');
		    OPND.XW.I := 1;
		    end
		else
		    TOO_COMPLICATED := true;
		end (*NVPAS = 1*);

		(*NVPAS = *) 2:
		begin
		if FPA.MEMADR.LVL > 0 then
		    TOO_COMPLICATED := true
		else if IS_SIMPLE(VPA1)
		   and FITS_SHORT_INDEX(VPA2) then
		    begin
		    XTNDED_REGDISP_OPERAND (OPND,
			VPA1.VPA.RGADR, FPA.MEMADR.DSPLMT);
		    INSERT_SHORT_VPA (OPND, VPA2);
		    if FINALIND = IND1 then OPND.XW.I := 1;
		    end
		else if IS_SIMPLE(VPA2)
		   and FITS_SHORT_INDEX(VPA1) then
		    begin
		    XTNDED_REGDISP_OPERAND (OPND,
			VPA2.VPA.RGADR, FPA.MEMADR.DSPLMT);
		    INSERT_SHORT_VPA (OPND, VPA1);
		    if FINALIND = IND1 then OPND.XW.I := 1;
		    end
		else
		    TOO_COMPLICATED := true
		end (*NVPAS = 2*)

	    end (*case NVPAS*)

	end (*with STK[STE] do*);

    end (*FIT_ADDRESS_IN_OPERAND*);

(** GET_OPERAND_CLASS:		GET_OPERAND GET_SHORT_OPERAND GET_ADDRESS **)
(**)

procedure GET_OPERAND (*(var OPND :  OPERAND;  STE :  STKINX)*);
    (*Build an operand which accesses the quantity described
	 by the datum in STK[STE], simplifying the datum as
	 necessary.*)

    var TOO_COMPLICATED :  boolean;

    begin
    if STK[STE].DTYPE = TYPUB then
	if STK[STE].BREPRES = BJUMP then BJUMP_TO_BINTVAL (STE);
    FIT_IN_OPERAND (TOO_COMPLICATED, OPND, STE);
    while TOO_COMPLICATED do
	begin
	SIMPLIFY (STE);
	FIT_IN_OPERAND (TOO_COMPLICATED, OPND, STE);
	end;
    if STK[STE].DTYPE = TYPUS then			 (*setch*)
	TWIDDLE_OPERAND(OPND, WHICHPART*DOUBLEWORDUNITS);(*setch*)
    end (*GET_OPERAND*);



procedure GET_SHORT_OPERAND (var OPND :  OPERAND;  STE :  STKINX);
    (*Build a short operand which accesses the quantity described
	 by the datum, simplifying as necessary.*)

    var OPNDR :  OPERAND;

    begin
    GET_OPERAND (OPND, STE);
    if OPND.X = 1 then
	begin  (*generate a MOV*)
	FREEDATUMREGS (STE);
	if STK[STE].DTYPE = TYPUS then			  (*peg 27sep79...*)
	    FINDRGBLOCK(S1SETREP_SIZE)
	else if IS_DOUBLE[STK[STE].DTYPE] then FINDRP else FINDRG; (*...peg 27sep79*)
	REG_OPERAND (OPNDR, NXTRG);
	EMITXOP (MOV_X_X[STK[STE].DTYPE], OPNDR, OPND);
	REG_DATUM (STE, STK[STE].CODESTART,
		       STK[STE].DTYPE, NXTRG);
	OPND := OPNDR;
	end (*generate a MOV*);
    end (*GET_SHORT_OPERAND*);



procedure GET_ADDRESS (var OPND :  OPERAND;  STE :  STKINX);
    (*The datum describes a quantity of type address.  Build an
	operand accessing the location with that address,
	simplifying the datum as necessary. (Approximately
	GET_OPERAND with one more level of indirection
	on the datum) *)

    var TOO_COMPLICATED :  boolean;

    begin
    FIT_ADDRESS_IN_OPERAND (TOO_COMPLICATED, OPND, STE);
    while TOO_COMPLICATED do
	begin
	SIMPLIFY (STE);
	FIT_ADDRESS_IN_OPERAND (TOO_COMPLICATED, OPND, STE);
	end
    end (*GET_ADDRESS*);

(** GET_OPERAND_CLASS:		MOVE_QUANTITY SLR_QUANTITY COERCE_AND_MOVE_QUANTITY STORE **)
(**)

procedure MOVE_QUANTITY (*(var DEST :  OPERAND; STE :  STKINX)*);
    (*Emit code to calculate the datum and move to location given
	by operand.  Do *Not* change datum to reflect move, but
	simplification changes may take place.*)

    var SOURCE :  OPERAND;
	TOOMUCH :  boolean;

    begin
    with STK[STE] do
	if (DTYPE=TYPUA) and (FINALIND=IND0) then
	    begin
	    (*This attempts to optimize the case of an unindirected
		address, without going to a lot of work.  To do it
		right every time would require a loop here like
		the loops in the integer arithmetic instructions.*)
	    FIT_IN_OPERAND (TOOMUCH, SOURCE, STE);
	    if TOOMUCH then
		begin
		GET_ADDRESS (SOURCE, STE);
		EMITXOP (XMOV_A, DEST, SOURCE);
		end
	    else
		EMITXOP (XMOV_S_S, DEST, SOURCE)
	    end
	else
	    begin
	    GET_OPERAND (SOURCE, STE);
	    if DEST<>SOURCE then
		EMITXOP (MOV_X_X[DTYPE], DEST, SOURCE);
	    end;
    end (*MOVE_QUANTITY*);

procedure SLR_QUANTITY (DEST :  OPERAND;  REGNUM :  S1REGISTER;
			STE :  STKINX);
    (*Emit code to calculate the datum and load it into register REGNUM
	while saving the previous contents of the register in the word
	specified by the operand, using the SLR.'REGNUM' instruction.
	Do *Not* change the datum to reflect the move, but
	simplification changes may take place.*)

    var SOURCE :  OPERAND;
	TOOMUCH :  boolean;

    begin
    with STK[STE] do
	if (DTYPE=TYPUA) and (FINALIND=IND0) then
	    begin
	    (*This attempts to optimize the case of an unindirected
		address, without going to a lot of work.  To do it
		right every time would require a loop here like
		the loops in the integer arithmetic instructions.*)
	    FIT_IN_OPERAND (TOOMUCH, SOURCE, STE);
	    if TOOMUCH then
		begin
		GET_ADDRESS (SOURCE, STE);
		EMITXOP (SLRADR_N[REGNUM], DEST, SOURCE);
		end
	    else
		EMITXOP (SLR_N[REGNUM], DEST, SOURCE)
	    end
	else
	    begin
	    GET_OPERAND (SOURCE, STE);
	    EMITXOP (SLR_N[REGNUM], DEST, SOURCE);
	    end;
    end (*SLR_QUANTITY*);



procedure COERCE_AND_MOVE_QUANTITY (var DEST :	OPERAND;
		     STE :  STKINX;  RESTYPE :	OPNDTYPE);
    (*Get the datum to the location specified by the operand,
	coercing it to type RESTYPE.  Do *Not* change datum to
	reflect coercion, but simplification changes may occur.*)

    var SOURCE :  OPERAND;
	MOVEOP :  S1OPCODE;
	TOOMUCH :  boolean;

    begin
    with STK[STE] do
	if (DTYPE = TYPUA) and (RESTYPE = TYPUA) 
	  and (FINALIND = IND0) then
	    begin
	    (*This attempts to optimize the case of an unindirected
		address, without going to a lot of work.  To do it
		right every time would require a loop here like
		the loops in the integer arithmetic instructions.*)
	    FIT_IN_OPERAND (TOOMUCH, SOURCE, STE);
	    if TOOMUCH then
		begin
		GET_ADDRESS (SOURCE, STE);
		EMITXOP (XMOV_A, DEST, SOURCE);
		end
	    else
		EMITXOP (XMOV_S_S, DEST, SOURCE)
	    end
	else
	    begin
	    GET_OPERAND (SOURCE, STE);
	    if not EQUAL_OPERANDS(DEST, SOURCE) or (DTYPE <> RESTYPE)
	    then
		begin  (*Use ordinary MOV*)
		MOVEOP := MOV_X_Y[RESTYPE, DTYPE];
		if MOVEOP = XILLEGAL then
		    ERROR (WCOERCION_INVALID);
		EMITXOP (MOVEOP, DEST, SOURCE);
		end;
	    end (*Use ordinary MOV*);
    end (*COERCE_AND_MOVE_QUANTITY*);


procedure STORE(DEST, SOURCE :	STKINX);
	    (*For the future, consider doing STORE without always using
	     a MOV:  (apropos for peephole).*)
    (*Emit code to store the operand represented by SOURCE at the
     address represented by DEST.*)

    var OPND1 (*,OPND2*) : OPERAND;
	MOVEOP :  S1OPCODE;

    begin
    MOVEOP := MOV_X_Y[TYP,STK[SOURCE].DTYPE];
    if MOVEOP = XILLEGAL then ERROR(WINCOMPATIBLE_TYPES);
    (*Possible optimizing heuristic: GET_OPERAND before GET_ADDRESS*)
    GET_ADDRESS(OPND1,DEST);
    COERCE_AND_MOVE_QUANTITY(OPND1,SOURCE,TYP)
	(*or, GET_OPERAND(OPND2,SOURCE); EMITXOP(MOVEOP,OPND1,OPND2)*)
    end (*STORE*);

(** SIMPLIFY_CLASS:		ADD_SUB_SINGLE INC_OR_DEC ADD_TOP_TWO_DATUMS MULT_SINGLE SIMPLIFY ADD_VPAS FPA_LVL_PLUS_VPA1 FPA_DSPLMT_PLUS_VPA1 VPA_FPA_FINALIND SHORT_AND_REG CALCULATE_FPA DEREF_AND_SHIFT SHIFT_VPA1 DEREF DEREF_TO_END **)
(**)

procedure ADD_SUB_SINGLE (*(var DEST :  S1REGISTER;  ADDOP :  S1OPCODE;
			  var OPND1, OPND2 :  OPERAND; STE :  STKINX)*);
    (*Add together the two singleword operands, optimizing
	to INC or DEC if possible.*)

    procedure INC_OR_DEC (INC :  integer;  var OPND :  OPERAND);
	var OPNDR :  OPERAND;
	    ADDOP :  S1OPCODE;
	begin
	if INC=1 then ADDOP:=XINC_S else ADDOP:=XDEC_S;
	if IS_T_REG(OPND) then DEST := OPND.F			(*14FEB79 PTZ*)
	else
	    begin
	    FINDRG;   DEST := NXTRG
	    end;
	REG_OPERAND (OPNDR, DEST);
	EMITXOP (ADDOP, OPNDR, OPND);
	end (*INC_OR_DEC*);

    begin (*ADD_SUB_SINGLE*)
    if ISSHORTCONST(OPND1) and ((OPND1.F=1) or (OPND1.F=-1))	(*EJG 14FEB79*)
	and (ADDOP=XADD_S) then INC_OR_DEC(OPND1.F, OPND2)	(*EJG 14FEB79*)
    else if ISSHORTCONST(OPND2) and ((OPND2.F=1) or (OPND2.F=-1)) then
	if ADDOP=XADD_S then INC_OR_DEC(OPND2.F, OPND1)
			else INC_OR_DEC(-OPND2.F, OPND1)
    else
	ALLOC_AND_EMIT_TOP (DEST, ADDOP, OPND1, OPND2,
			    false, false, false, STE);
    end (*ADD_SUB_SINGLE*);



procedure ADD_TOP_TWO_DATUMS;
    (*Add the top two singlewords (integer or address) on the
	stack by combining and/or emitting code.  Sets DTYPE and
	CODESTART in the resultant datum.*)

    var COMBINABLE, ADDABLE, TOOMUCH1, TOOMUCH2 :  boolean;
	CONSTPART :  integer;
	OPND1, OPND2 :	OPERAND;
	UNSIMPLE, SIMPLER :  STKINX;
	DEST :	S1REGISTER;
	RESTYPE :  OPNDTYPE;

    begin
    COMBINABLE := false;
    ADDABLE := false;
    repeat
	if (STK[TOP].NVPAS=0) and (STK[TOP].FPA=ZEROFPA)
	   and (STK[TOP].DTYPE<>TYPUM) then
	    COMBINABLE := true
	else if (STK[TOP-1].NVPAS=0) and (STK[TOP-1].FPA=ZEROFPA)
	    and (STK[TOP-1].DTYPE<>TYPUM) then
	      COMBINABLE := true
	else
	if (STK[TOP].FINALIND=IND0)
	and (STK[TOP-1].FINALIND=IND0)
	and ( ((STK[TOP].FPA.MEMADR.LVL=0) and (STK[TOP].DTYPE<>TYPUM))
	     or ((STK[TOP-1].FPA.MEMADR.LVL=0) and (STK[TOP-1].DTYPE<>TYPUM)) )
	and (STK[TOP].NVPAS + STK[TOP-1].NVPAS <= 2) then
	    COMBINABLE := true

	else
	    begin  (*not combinable*)
	    if (STK[TOP].FINALIND = IND0) and
	       (STK[TOP-1].FINALIND = IND0) then
		begin
		CONSTPART := STK[TOP].FPA.MEMADR.DSPLMT
			+ STK[TOP-1].FPA.MEMADR.DSPLMT;
		STK[TOP].FPA.MEMADR.DSPLMT := 0;
		STK[TOP-1].FPA.MEMADR.DSPLMT := 0;
		end
	    else
		CONSTPART := 0;
	    FIT_IN_OPERAND (TOOMUCH1, OPND1, TOP-1);
	    FIT_IN_OPERAND (TOOMUCH2, OPND2, TOP);
	    if not TOOMUCH1 and not TOOMUCH2 then
		ADDABLE := true
	    else
		begin  (*must simplify*)
		if not TOOMUCH1 then
		    begin
		    UNSIMPLE := TOP;
		    SIMPLER := TOP-1;
		    end
		else if not TOOMUCH2 then
		    begin
		    UNSIMPLE := TOP-1;
		    SIMPLER := TOP;
		    end
		else
		    begin   (*Pick one at random*)
		    UNSIMPLE := TOP;
		    SIMPLER := TOP-1;
		    end;
		if CONSTPART <> 0 then
		    begin
		    if not ((STK[UNSIMPLE].FINALIND = IND0) and
		      (STK[UNSIMPLE].FPA.MEMADR.DSPLMT = 0) ) then
			ASSERTFAIL('ADD_TOP_T001');
		    STK[UNSIMPLE].FPA.MEMADR.DSPLMT := CONSTPART;
		    end;
		SIMPLIFY (UNSIMPLE);
		end (*must simplify*);
	    end (*not combinable*)
    until COMBINABLE or ADDABLE;

    if (STK[TOP-1].DTYPE=TYPUM) or (STK[TOP].DTYPE=TYPUM) then
	RESTYPE := TYPUM
    else if (STK[TOP-1].DTYPE=TYPUA) or (STK[TOP].DTYPE=TYPUA) then
	RESTYPE := TYPUA
    else if (STK[TOP-1].DTYPE=TYPUL) and (STK[TOP].DTYPE=TYPUL) then
	RESTYPE := TYPUL
    else RESTYPE := TYPUJ;

    if ADDABLE then

	begin  (*ADDABLE*)
	if RESTYPE in [TYPUJ, TYPUL] then
	    begin
	    COERCE_INT_DATUM(TOP-1);
	    COERCE_INT_DATUM(TOP);
	    end (*TYPUJ, TYPUL*);

	ADD_SUB_SINGLE (DEST, XADD_S, OPND1, OPND2, TOP-1);
	FREEREGSBUTTHESE (TOP, [DEST]);
	POPTOP;
	FREEREGSBUTTHESE (TOP, [DEST]);
	REG_DATUM (TOP, STK[TOP].CODESTART, RESTYPE, DEST);
	STK[TOP].DTYPE := RESTYPE;
	end (*ADDABLE*)

    else

	begin  (*COMBINABLE*)
	if (STK[TOP-1].NVPAS=0) and
	  (STK[TOP-1].FPA=ZEROFPA) and (STK[TOP-1].DTYPE<>TYPUM) then
	    STK[TOP-1] := STK[TOP]
	else if (STK[TOP].NVPAS=0) and
	    (STK[TOP].FPA=ZEROFPA) and (STK[TOP].DTYPE<>TYPUM) then
	    (*Top is zero so just throw it away.*)
	else
	    begin  (*Both datums have FINALIND = IND0.*)
	    if STK[TOP].FPA.MEMADR.LVL<>0 then
		STK[TOP-1].FPA.MEMADR.LVL := STK[TOP].FPA.MEMADR.LVL;
	    STK[TOP-1].FPA.MEMADR.DSPLMT :=
		STK[TOP].FPA.MEMADR.DSPLMT + STK[TOP-1].FPA.MEMADR.DSPLMT;
	    if STK[TOP-1].NVPAS = 0 then
		begin
		if STK[TOP].NVPAS > 0 then
		    STK[TOP-1].VPA1 := STK[TOP].VPA1;
		if STK[TOP].NVPAS = 2 then
		    STK[TOP-1].VPA2 := STK[TOP].VPA2;
		end
	    else if (STK[TOP-1].NVPAS=1) and (STK[TOP].NVPAS=1) then
		STK[TOP-1].VPA2 := STK[TOP].VPA1;
	    STK[TOP-1].NVPAS := STK[TOP-1].NVPAS+STK[TOP].NVPAS;
	    end (*Both datums have FINALIND = IND0*);
	if RTBUSER = TOP then RTBUSER := TOP-1;
	POPTOP;
	end (*COMBINABLE*);

    end (*ADD_TOP_TWO_DATUMS*);





procedure MULT_SINGLE (var DEST :  S1REGISTER;
		       var OPND1, OPND2 :  OPERAND;  STE :  STKINX);
    (*Multiply together the two singleword operands, optimizing to
	shift if possible.  Note that because of negatives, a right
	shift is *Not* equivalent to a divide.*)
    (*Note - at present this procedure only considers short
	constants for possible translations into shifts.
	When real S1WORDs make it easier to consider extended
	constants, this should be improved.*)

    var SHIFTDIST :  integer;
	OPNDI :  OPERAND;

    begin

    if ISSHORTCONST(OPND1) then
	begin
	SHIFTDIST := POWER2 (OPND1.F);
	if SHIFTDIST >= 0 then
	    begin
	    IMM_OPERAND (OPNDI, SHIFTDIST);
	    ALLOC_AND_EMIT_TOP (DEST, XSHFA_LF_S, OPND2, OPNDI,
				false, false, false, STE);
	    end
	else
	    ALLOC_AND_EMIT_TOP (DEST, XMULT_S, OPND1, OPND2,
				false, false, false, STE);
	end

    else if ISSHORTCONST(OPND2) then
	begin
	SHIFTDIST := POWER2 (OPND2.F);
	if SHIFTDIST >= 0 then
	    begin
	    IMM_OPERAND (OPNDI, SHIFTDIST);
	    ALLOC_AND_EMIT_TOP
		(DEST, XSHFA_LF_S, OPND1, OPNDI,
		 false, false, false, STE);
	    end
	else
	    ALLOC_AND_EMIT_TOP (DEST, XMULT_S, OPND1, OPND2,
				false, false, false, STE);
	end

    else
	ALLOC_AND_EMIT_TOP (DEST, XMULT_S, OPND1, OPND2,
			    false, false, false, STE);

    end (*MULT_SINGLE*);




procedure SIMPLIFY (*(STE :  STKINX)*);
    (*By doing a very small amount of work - about one instruction -
	simplify the datum so that it is closer to fitting in an
	operand.  Repeated calls to this procedure are guaranteed to
	eventually get it so it will fit.  One more call will get the
	quantity into a register if it is not a constant: beyond this
	point it is an error to call SIMPLIFY.*)

    var OPND :	OPERAND;
	UNKNOWN_LOC : integer;


    procedure ADD_VPAS;
	(*Build operands for VPA1 and VPA2, both of which have zero
	    shifts.  Generate an ADD instruction to combine the two
	    into a simple register.  This is guaranteed not to
	    completely sum the parts of the datum if the datum is
	    an address.*)

	var OPND1, OPND2 :  OPERAND;
	    DEST :  S1REGISTER;

	begin
	with STK[STE] do
	    begin
	    if not ((VPA1.VSHIFT=0) and (VPA2.VSHIFT=0)) then
		ASSERTFAIL('ADD_VPAS 001');
	    if not ((FINALIND>IND0) or (DTYPE in [TYPUA,TYPUM,TYPUJ,TYPUL])) then
		ASSERTFAIL('ADD_VPAS 002');
	    VPA_OPERAND_NOSHIFT (OPND1, VPA1);
	    VPA_OPERAND_NOSHIFT (OPND2, VPA2);
	    ALLOC_AND_EMIT_TOP (DEST, XADD_S, OPND1, OPND2,
				false, false, false, STE);
	    FREVPARGUNLESS (VPA1, DEST);
	    FREVPARGUNLESS (VPA2, DEST);
	    VPA1 := ZEROVPA;   VPA2 := ZEROVPA;
	    NVPAS := 1;
	    VPA1.VPA.WHICH := RGS;
	    VPA1.VPA.RGADR := DEST;
	    end (*with STK[STE]*)
	end (*ADD_VPAS*);


    procedure FPA_LVL_PLUS_VPA1 (var OPND :  OPERAND);
	(*OPND describes VPA1.	Emit an ADD instruction to
	    combine this with the FPA level, replacing them
	    by a simple register.  This is guaranteed not to
	    completely sum the parts of the datum.*)

	var OPND2 :  OPERAND;
	    DEST :  S1REGISTER;

	begin
	with STK[STE] do
	    begin
	    if not ((FPA.MEMADR.LVL > 0) and
		    ((DTYPE=TYPUA) or (FINALIND>IND0)) ) then
		ASSERTFAIL('FPLVL_VPA001');
	    REG_OPERAND (OPND2, LVL_TO_S1REG [FPA.MEMADR.LVL] );
	    ALLOC_AND_EMIT_TOP (DEST, XADD_S, OPND, OPND2,
				false, false, false, STE);
	    FREVPARGUNLESS (VPA1, DEST);
	    VPA1 := ZEROVPA;
	    FPA.MEMADR.LVL := 0;
	    VPA1.VPA.WHICH := RGS;
	    VPA1.VPA.RGADR := DEST;
	    end (*with STK[STE]*)
	end (*FPA_LVL_PLUS_VPA1*);


    procedure FPA_DSPLMT_PLUS_VPA1 (var OPND :	OPERAND);
	(*OPND describes VPA1.	Emit an ADD instruction
	    to add this VPA to the FPA displacement,
	    resulting in a single register VPA.*)

	var OPND2 :  OPERAND;
	    DEST :  S1REGISTER;

	begin
	with STK[STE] do
	    begin
	    if not ((FINALIND=IND0) and
(*peg 18sep79*)	    (DTYPE in [TYPUB, TYPUC, TYPUJ, TYPUL])) then
		ASSERTFAIL('FDSP_VPA 001');
	    IMM_OPERAND (OPND2, FPA.MEMADR.DSPLMT);
	    ADD_SUB_SINGLE (DEST, XADD_S, OPND, OPND2, STE);
	    FREVPARGUNLESS (VPA1, DEST);
	    FPA.MEMADR.DSPLMT := 0;
	    VPA1 := ZEROVPA;
	    VPA1.VPA.WHICH := RGS;
	    VPA1.VPA.RGADR := DEST
	    end (*with STK[STE]*)
	end (*FPA_DSPLMT_PLUS_VPA1*);


    procedure VPA_FPA_FINALIND;
	(*The datum consists of a short-index VPA and an FPA,
	    with some value of FINALIND.  Completely simplify it
	    using address arithmetic into a single register.*)

	var OPND1, OPND2 :  OPERAND;
	    MOVEOP : S1OPCODE;

	begin
	with STK[STE] do
	    if IS_SIMPLE(VPA1) and (DTYPE<>TYPUM)
	       and (FPA.MEMADR.LVL = 0)
	       and FITS_SHRT_OFFSET (FPA.MEMADR.DSPLMT) then
	    begin  (*non-level register and short offset*)
	    if FINALIND = IND2 then
		begin
		ADDR_OPERAND (OPND2, 0);
		OPND2.REG := VPA1.VPA.RGADR;
		OPND2.F := FPA.MEMADR.DSPLMT div WORDUNITS;
		FREEDATUMREGS (STE);
		MOVEOP := MOV_X_X[DTYPE];
(*peg 27sep79*) if DTYPE = TYPUS then
(*peg 27sep79*)	    FINDRGBLOCK(S1SETREP_SIZE)
(*peg 27sep79*) else if IS_DOUBLE[DTYPE] then FINDRP else FINDRG;
		end
	    else
		begin
		REGDISP_OPERAND (OPND2, VPA1.VPA.RGADR,
				 FPA.MEMADR.DSPLMT);
		FREEDATUMREGS (STE);
		if FINALIND = IND0 then
		    begin  MOVEOP := XMOV_A;  FINDRG;  end
		else
		    begin
		    MOVEOP := MOV_X_X[DTYPE];
(*peg 27sep79*)     if DTYPE = TYPUS then
(*peg 27sep79*)	        FINDRGBLOCK(S1SETREP_SIZE)
(*peg 27sep79*)     else if IS_DOUBLE[DTYPE] then FINDRP else FINDRG;
		    end;
		end;

	    REG_DATUM (STE, CODESTART, DTYPE, NXTRG);
	    REG_OPERAND (OPND1, NXTRG);
	    EMITXOP (MOVEOP, OPND1, OPND2);
	    end (*non-level register and short offset*)

	  else
	    begin
	    if not (((DTYPE in [TYPUA,TYPUM]) or (FINALIND>IND0))
		    and (NVPAS=1) and FITS_SHORT_INDEX(VPA1) ) then
		ASSERTFAIL('VP_FP_FIN001');
	    if FPA.MEMADR.LVL > 0 then
		XTNDED_REGDISP_OPERAND (OPND2,
			     LVL_TO_S1REG [FPA.MEMADR.LVL],
			     FPA.MEMADR.DSPLMT)
	    else if DTYPE <> TYPUM then
		ADDR_OPERAND (OPND2, FPA.MEMADR.DSPLMT)
	    else
		begin
		XTNDED_REGDISP_OPERAND (OPND2,
			     S1RPC, FPA.MEMADR.DSPLMT);
		OPND2.FIXUP := STRINGFIX;
		DTYPE := TYPUA;
		end;

	    INSERT_SHORT_VPA (OPND2, VPA1);
	    FREEDATUMREGS (STE);
	    if FINALIND = IND0 then
		begin
		MOVEOP := XMOV_A;   FINDRG
		end
	    else
		begin
		MOVEOP := MOV_X_X[DTYPE];
(*pn 27sep79...*)  if DTYPE = TYPUS then
			FINDRGBLOCK(S1SETREP_SIZE)
(*...pn 27sep79*)  else if IS_DOUBLE[DTYPE] then FINDRP else FINDRG;
		if FINALIND = IND2 then OPND2.XW.I := 1;
		end;
	    REG_DATUM (STE, CODESTART, DTYPE, NXTRG);
	    REG_OPERAND (OPND1, NXTRG);
	    EMITXOP (MOVEOP, OPND1, OPND2);
	    end (*with STK[STE]*)
	end (*VPA_FPA_FINALIND*);


    procedure SHORT_AND_REG (var VSHORT, VREG :  VPAREC);
	(*Combine the two VPAs and the FPA displacement into
	    a simple register by address arithmetic.  Allow
	    for the possibility that this may completely sum
	    the parts; in that case include FINALIND in the
	    operand to completely simplify the datum.  Note
	    that the FPA level may be implicit due to DTYPE=TYPUM.*)

	var OPND1, OPND2 :  OPERAND;
	    MOVEOP :  S1OPCODE;

	begin
	with STK[STE] do
	    begin
	    if not ((DTYPE in [TYPUA,TYPUM]) or (FINALIND > IND0) ) then
		ASSERTFAIL('SHORT®001');
	    XTNDED_REGDISP_OPERAND (OPND2,
		       VREG.VPA.RGADR, FPA.MEMADR.DSPLMT);
	    INSERT_SHORT_VPA (OPND2, VSHORT);
	    FPA.MEMADR.DSPLMT := 0;
	    FREEVPAREG (VPA1);
	    FREEVPAREG (VPA2);
	    VPA1 := ZEROVPA;   VPA2 := ZEROVPA;
	    NVPAS := 1;
	    if (FINALIND=IND0) or
	       (FPA.MEMADR.LVL>0) or (DTYPE=TYPUM) then
		begin
		MOVEOP := XMOV_A;   FINDRG
		end
	    else
		begin
		MOVEOP := MOV_X_X [DTYPE];
(*pn 27sep79...*)  if DTYPE = TYPUS then
			FINDRGBLOCK(S1SETREP_SIZE)
(*...pn 27sep79*)  else if IS_DOUBLE[DTYPE] then FINDRP else FINDRG;
		if FINALIND = IND2 then OPND2.XW.I := 1;
		FINALIND := IND0;
		end;

	    VPA1.VPA.WHICH := RGS;
	    VPA1.VPA.RGADR := NXTRG;
	    REG_OPERAND (OPND1, NXTRG);
	    EMITXOP (MOVEOP, OPND1, OPND2);
	    end (*with STK[STE]*)
	end (*SHORT_AND_REG*);


    procedure CALCULATE_FPA;
	(*Combine the FPA level and displacement by address
	    arithmetic.  The level may be implicitly PC-relative
	    by virtue of the datum's being TYPUM.  Assume no
	    VPAs and FINALIND = IND0.*)

	var OPND1, OPND2 :  OPERAND;

	begin
	with STK[STE] do
	    begin
	    if not ((DTYPE in [TYPUA,TYPUM]) and
		    (NVPAS=0) and (FINALIND=IND0) ) then
		ASSERTFAIL('CALC_FPA 001');
	    FINDRG;
	    REG_OPERAND (OPND1, NXTRG);
	    if DTYPE <> TYPUM then
		REGDISP_OPERAND (OPND2,
			 LVL_TO_S1REG [FPA.MEMADR.LVL],
			 FPA.MEMADR.DSPLMT)
	    else
		begin
		XTNDED_REGDISP_OPERAND
		     (OPND2, S1RPC, FPA.MEMADR.DSPLMT);
		OPND2.FIXUP := STRINGFIX;
		DTYPE := TYPUA;
		end;
	    FPA := ZEROFPA;
	    NVPAS := 1;
	    VPA1.VPA.WHICH := RGS;
	    VPA1.VPA.RGADR := NXTRG;
	    EMITXOP (XMOV_A, OPND1, OPND2);
	    end (*with STK[STE]*)
	end (*CALCULATE_FPA*);


    procedure DEREF_AND_SHIFT (var V :	VPAREC);
	(*Build an operand from the VPA neglecting shift and
	    emit a SHIFT instruction to reduce the VPA to
	    a simple register.*)

	var OPND1, OPND2 :  OPERAND;
	    DEST :  S1REGISTER;

	begin
	with STK[STE] do
	    if not ((FINALIND>IND0) or (DTYPE in [TYPUA,TYPUM,TYPUJ,TYPUL]) ) then
                ASSERTFAIL('DEREFSHFT001');
	VPA_OPERAND_NOSHIFT (OPND1, V);
	IMM_OPERAND (OPND2, V.VSHIFT);
	ALLOC_AND_EMIT_TOP (DEST, XSHFA_LF_S, OPND1, OPND2,
			    false, false, false, STE);
	FREVPARGUNLESS (V, DEST);
	V := ZEROVPA;
	V.VPA.WHICH := RGS;
	V.VPA.RGADR := DEST;
	end (*DEREF_AND_SHIFT*);


    procedure SHIFT_VPA1 (var OPND :  OPERAND);
	(*OPND describes VPA1.	Emit a SHIFT instruction to
	    reduce VPA1 to a simple register.*)

	var OPND2 :  OPERAND;
	    DEST :  S1REGISTER;

	begin
	with STK[STE] do
	    begin
	    if not ((FINALIND>IND0) or (DTYPE in [TYPUA,TYPUM,TYPUJ,TYPUL]) ) then
		ASSERTFAIL('SHIFTVPA 001');
	    IMM_OPERAND (OPND2, VPA1.VSHIFT);
	    ALLOC_AND_EMIT_TOP (DEST, XSHFA_LF_S, OPND, OPND2,
				false, false, false, STE);
	    FREVPARGUNLESS (VPA1, DEST);
	    VPA1 := ZEROVPA;
	    VPA1.VPA.WHICH := RGS;
	    VPA1.VPA.RGADR := DEST;
	    end (*with STK[STE]*)
	end (*SHIFT_VPA1*);


    procedure DEREF (var V :  VPAREC;  var OPND :  OPERAND);
	(*OPND describes the VPA, posibly with additional
	    indirection.  Generate a MOV using this operand,
	    which will reduce the VPA to a simple register without
	    completely simplifying the datum.  (Both these
	    conditions are assured by the caller.)*)

	var OPNDR :  OPERAND;

	begin
	FREEVPAREG (V);
	FINDRG;
	REG_OPERAND (OPNDR, NXTRG);
	EMITXOP (XMOV_S_S, OPNDR, OPND);
	V := ZEROVPA;
	V.VPA.WHICH := RGS;
	V.VPA.RGADR := NXTRG
	end (*DEREF*);


    procedure DEREF_TO_END (var V :  VPAREC;
		       var OPND :  OPERAND;  DTYPE :  OPNDTYPE);
	(*OPND describes the VPA, possibly with some extra
	    indirection.  Generate a MOV using this operand to
	    reduce the VPA to a simple register.  This operation
	    is guaranteed to completely simplify the datum, which
	    is of type DTYPE.*)

	var OPNDR :  OPERAND;

	begin
	FREEVPAREG (V);
(*pn 27sep79...*)  if STK[STE].DTYPE = TYPUS then
			FINDRGBLOCK(S1SETREP_SIZE)
(*...pn 27sep79*)  else if IS_DOUBLE[DTYPE] then FINDRP else FINDRG;
	REG_OPERAND (OPNDR, NXTRG);
	EMITXOP (MOV_X_X[DTYPE], OPNDR, OPND);
	V := ZEROVPA;
	V.VPA.WHICH := RGS;
	V.VPA.RGADR := NXTRG;
	end (*DEREF_TO_END*);


    begin  (*SIMPLIFY*)
    with STK[STE] do
	begin
	if FPA.WHICH = RGS then
	    ERROR (WINDEXING_IN_PARMS);

	if (FINALIND=IND0) and not(DTYPE in [TYPUA,TYPUM]) then
	    begin  (*no address arithmetic allowed*)
	    if FPA.MEMADR.LVL <> 0 then ASSERTFAIL('SIMPLIFY 001');

	    case NVPAS of

		(*NVPAS = *) 0:
		if not ( false) then ASSERTFAIL('SIMPLIFY 002');

		(*NVPAS = *) 1:
		begin
		VPA_OPERAND_NOSHIFT (OPND, VPA1);
		if VPA1.VSHIFT > 0 then
		    SHIFT_VPA1 (OPND)
		else if FPA.MEMADR.DSPLMT <> 0 then
		    FPA_DSPLMT_PLUS_VPA1 (OPND)
		else
		    begin
		    if not ( not IS_SIMPLE(VPA1) ) then
			ASSERTFAIL('SIMPLIFY 003');
		    DEREF_TO_END (VPA1, OPND, DTYPE);
		    end
		end (*NVPAS = 1*);

		(*NVPAS = *) 2:
		if VPA1.VSHIFT > 0 then
		    DEREF_AND_SHIFT (VPA1)
		else if VPA2.VSHIFT > 0 then
		    DEREF_AND_SHIFT (VPA2)
		else
		    ADD_VPAS;

		end (*case NVPAS*);

	    end (*no address arithmetic allowed*)

	else
	    begin (*address arithmetic allowed.  In fact, to
		   prevent an address from looking like an
		   indirect address pointer, address arithmetic
		   is required if a non-address operation
		   would completely simplify the datum.*)
	    case NVPAS of

		(*NVPAS = *) 0:
		begin
		if not ((DTYPE = TYPUM) or
			(FPA.MEMADR.LVL>0) and (FPA.MEMADR.DSPLMT<>0) ) then
		    ASSERTFAIL('SIMPLIFY 004');
		CALCULATE_FPA
		end (*NVPAS = 0*);

		(*NVPAS = *) 1:
		begin
		if not (not ((DTYPE<>TYPUM) and (FPA=ZEROFPA) and
			      IS_SIMPLE(VPA1) ) ) then
		    ASSERTFAIL('SIMPLIFY 005');

		if FITS_SHORT_INDEX (VPA1) then
		    VPA_FPA_FINALIND

		else
		    begin  (*requires extended address*)
		    VPA_OPERAND_NOSHIFT (OPND, VPA1);
		    if VPA1.VSHIFT > 0 then
			begin
			if (FPA=ZEROFPA) and (DTYPE<>TYPUM) then
			    ERROR (WINDEX_WITHOUT_BASE);
			SHIFT_VPA1 (OPND)
			end
		    else if (FPA.MEMADR.LVL>0)
			    and (FPA.MEMADR.DSPLMT<>0) then
			FPA_LVL_PLUS_VPA1 (OPND)
		    else if (DTYPE=TYPUM) or (FPA<>ZEROFPA) then
			DEREF (VPA1, OPND)
		    else
			begin  (*dereference some or all the way*)
			if not (OPND.X = 1) then ASSERTFAIL('SIMPLIFY 006');
			if (FINALIND>IND0) and (OPND.XW.I=0) then
			    begin
			    OPND.XW.I := 1;
			    FINALIND := pred(FINALIND);
			    end;
			if FINALIND = IND0 then
			    DEREF_TO_END (VPA1, OPND, DTYPE)
			else
			    begin
			    DEREF (VPA1, OPND);
			    VPA1.VPAIND := IND2;
			    FINALIND := pred(FINALIND)
			    end;
			end (*dereference*)
		    end (*requires extended address*)
		end (*NVPAS = 1*);

		(*NVPAS = *) 2:
		if IS_SIMPLE(VPA1) and
			  FITS_SHORT_INDEX(VPA2) then
		    SHORT_AND_REG (VPA2, VPA1)

		else if IS_SIMPLE(VPA2) and
			  FITS_SHORT_INDEX(VPA1) then
		    SHORT_AND_REG (VPA1, VPA2)

		else if (DTYPE<>TYPUM) and (FPA=ZEROFPA) then
		    begin
		    (*be careful not to finish simplification
			with integer arithmetic.*)
		    if VPA1.VSHIFT > 0 then
			DEREF_AND_SHIFT (VPA1)
		    else if not IS_SIMPLE(VPA1) then
			begin
			VPA_OPERAND_NOSHIFT (OPND, VPA1);
			DEREF (VPA1, OPND)
			end
		    else if VPA2.VSHIFT > 0 then
			DEREF_AND_SHIFT (VPA2)
		    else
			begin
			VPA_OPERAND_NOSHIFT (OPND, VPA2);
			DEREF (VPA2, OPND)
			end
		    end (*be careful...*)

		else if VPA1.VSHIFT > 0 then
		    DEREF_AND_SHIFT (VPA1)

		else if VPA2.VSHIFT > 0 then
		    DEREF_AND_SHIFT (VPA2)

		else
		    ADD_VPAS;

		end (*case NVPAS*);

	    end (*address arithmetic allowed*)

	end (*with STK[STE]*);

    if TR_SIMP then
	begin
	WRITELN (OUTPUT, '      Instruction(s) emitted:');
	if OLDINSTREC = nil then OLDINSTREC := MAINCODE.FIRST;
	while OLDINSTREC <> nil do
	    begin
	    UNKNOWN_LOC := 0;
  	    DISASSEMBLE (UNKNOWN_LOC, OLDINSTREC); 
	    OLDINSTREC := OLDINSTREC↑.NEXTPTR;			(*DATASTRCH*)
	    end;
	OLDINSTREC := NEWINSTREC;
	WRITELN (OUTPUT, '      Datum simplified');
	PRINTDATUM (STE)
	end;

    end (*SIMPLIFY*);

(** DISASSEMBLE_CLASS:			DISASSEMBLE PRINTLOC PRINTIWORD PRINTXW1 PRINTXW2 PRINTOPERAND PRINTREG PRINT_SIGNED_OCTAL PRINTSHORTOP **)
(**)

procedure DISASSEMBLE(*(var CURPC :  integer; IPTR :  AN_INSTREC)*);(*DATASTRCH*)
    (*This procedure disassembles and prints a single S1 instruction
     starting at the word pointed to by IPTR, using CURPC as the
     location of that instruction, and updates CURPC to indicate the
     location of the next instruction.*)

    var CURS1OPC :  S1OPCODE;
	XPTR1, XPTR2 :  AN_OPERANDXWORD;			(*DATASTRCH*)
	T :  TWOBITS;
	SLOC :	CHAR10;
	I, J :  integer;						(*LCW*)
	ANS : CHAR12;

(* Output format :
.........1.........2.........3.........4.........5.........6.........7
locationxx :  instrwordxxx  opcodemnemonicx <operands>
	      xopnd1wordxx (if any)
	      xopnd2wordxx (if any)
*)

    procedure PRINTPTRADDR (IPTR : AN_INSTREC);   (*DATASTRCH*)(*15JAN79 PTZ*)
	var IPI : INSTREC_PTRINT;
	begin
	IPI.PTR := IPTR;
	WRITE(OUTPUT,'(',IPI.INT:8,')')
	end (*PRINTPTRADDR*);

    procedure PRINTLOC;
	var SLOC :  CHAR10;
	begin
	if not JUMPS_CONCRETIZED then				(*15JAN79 PTZ*)
	    PRINTPTRADDR(IPTR);					(*15JAN79 PTZ*)
	CVOS_10(SLOC,CURPC);
	WRITE(OUTPUT,SLOC,' :  ')
	end (*PRINTLOC*);

    procedure PRINTIWORD;
	var SWORD :  CHAR12;
	begin
	CVOS_S1WORD_12(SWORD,S1INSTBUF[S1INST]);
	WRITE(OUTPUT,SWORD,'  ')
	end (*PRINTIWORD*);

    procedure PRINTXW1;
	var SWORD :  CHAR12;
	begin
(*	if no xword1 test made before call			ALS*)(*DATASTRCH*)
  	CVOS_S1WORD_12(SWORD,S1INSTBUF[S1OPND1XWD]);		(*DATASTRCH*)
	if not JUMPS_CONCRETIZED then				(*15JAN79 PTZ*)
	    WRITE(OUTPUT,'          ');  (*space taken by ptr addr - PTZ*)
	WRITELN(OUTPUT,'              ',SWORD)
	end (*PRINTXW1*);

    procedure PRINTXW2;
	var SWORD :  CHAR12;
	begin
(*	if no xword2 test made before call			ALS*)(*DATASTRCH*)
	CVOS_S1WORD_12(SWORD,S1INSTBUF[S1OPND2XWD]);
	if not JUMPS_CONCRETIZED then				(*15JAN79 PTZ*)
	    WRITE(OUTPUT,'          ');  (*space taken by ptr addr - PTZ*)
	WRITELN(OUTPUT,'              ',SWORD)
	end (*PRINTXW2*);

    procedure PRINTOPERAND(var  OPND : INSTOPND);		(*DATASTRCH*)
	(*Disassemble and print one S1 operand contained in OPND. Extended
	 part (if any) is in the OPND.XWD↑ *)

    var I, J, K, KSIGN, KWID :	integer;
	OPNDX :  BIT;
	OPNDREG :  S1REGISTER;
	OPNDF :  MINSHORTOFFSET..MAXSHORTOFFSET;
	XWORD :  S1WORD;
	SWORD :  CHAR12;

	procedure PRINTREG(R :	S1REGISTER);
	    var
	    ANS : CHAR2;
	    I, J : 1..2;
	    begin
	    J := 1;  
	    if	    R = S1RTA then WRITE(OUTPUT,'%RTA')
	    else if R = S1RTB then WRITE(OUTPUT,'%RTB')
	    else
		begin
		WRITE (OUTPUT,'%');
		ANS[2] := chr(ord('0') + (R mod 8));
		R := R div 8;
		if R > 0 then ANS[1] := chr(ord('0') + R)
		else J := J + 1;
		for I := J to 2 do  WRITE(OUTPUT,ANS[I]);
		end
	    end (*PRINTREG*);

	procedure PRINT_SIGNED_OCTAL(K : integer);		(*30dec78 ALS*)
	    begin
	    IF K < 0 then
		begin
		K := - K;
		WRITE (OUTPUT,'-');
		end;
	    CVOS_12(ANS,K);
	    J := 1;
	    while ANS[J] = ' ' do J := J + 1;
	    for I := J to 12 do  WRITE(OUTPUT,ANS[I]);
	    end (*PRINT_SIGNED_OCTAL*);

	procedure PRINTSHORTOP;
	    begin
	    if	    OPNDREG = 0 then PRINTREG(OPNDF)
	    else if OPNDREG = 1 then
		begin (*short constant*)
		WRITE(OUTPUT,'#');
		PRINT_SIGNED_OCTAL(OPNDF);			(*31DEC78 ALS*)
		end (*short constant*)
	    else if OPNDREG = 2 then 
		begin
		if not (false) then
                ASSERTFAIL('PRINTSHOR001')
		end
	    else
		begin (*short indexed*)
		if not ((3 <= OPNDREG) and (OPNDREG <= LASTS1REG)) then
                    ASSERTFAIL('PRINTSHOR002');
		PRINT_SIGNED_OCTAL(OPNDF);			(*31DEC78 ALS*)
		WRITE(OUTPUT,'*4');	     (*FASM requires this  3JAN79 ALS*)
		WRITE(OUTPUT,'(');				(*31dec78 ALS*)
		PRINTREG(OPNDREG);
		WRITE(OUTPUT,')');
		end (*short indexed*)
	    end (*PRINTSHORTOP*);

    begin (*PRINTOPERAND*)
    with OPND do
	begin
	if XWD <> nil then OPNDX := 1
	else OPNDX := 0;
	OPNDREG := REG;
	OPNDF := F
	end(*with OPND*);

    if OPNDX = 1 then
	begin (*extended operand*)

	if (OPNDREG = 1) and (OPNDF <> 0) then
	    begin (*long constant*)

	    if not ((OPNDF>=1) and (OPNDF<=3)) then ASSERTFAIL('PRINTOPER001');
								(*DATASTRCH*)
	    XWORD := OPND.XWD↑.VAL;				(*DATASTRCH*)
	    KSIGN := GETSIGNEDFIELD(XWORD,0,6);
	    WRITE(OUTPUT,'#',CHR(124));					(*LCW*)
	    if ((KSIGN=0) or (KSIGN=-1)) and (OPNDF = 1) then
		begin (*print signed octal*)			(*30dec78 ALS*)
		K := GETSIGNEDFIELD(XWORD,WORDBITS-(BITS_ON_COMP_MACH-1),
		                    BITS_ON_COMP_MACH - 1);

		if not (((KSIGN=0) and (K>=0))
			 or ((KSIGN=-1) and (K<0))) then
		    ASSERTFAIL('PRINTOPER002');			(*DATASTRCH*)

		PRINT_SIGNED_OCTAL(K);				(*31DEC78 ALS*)
		end (*print signed octal*)
	    else
		begin (*print in octal*)
		CVOS_S1WORD_12(SWORD,XWORD);
		J := 1;
		while SWORD[J] = ' ' do J := J + 1;
		for I := J to 12 do  WRITE(OUTPUT,SWORD[I]);
		if OPNDF <> 1 then
		    begin
		    WRITE(OUTPUT,'F',OPNDF:1);                          (*???*)
		    end;
		end; (*print in octal*)					(*LCW*)
	    WRITE(OUTPUT,CHR(124));					(*LCW*)
	    end (*long constant*)
	else
	    begin (*extended address*)
	    WRITE(OUTPUT,CHR(124));					(*LCW*)
	    with OPND.XWD↑ do					(*DATASTRCH*)
		begin(*with OPND.XWD↑*)
		if I = 1 then					(*DATASTRCH*)
		    begin (*indirect bit*)
		    WRITE(OUTPUT,'@');                                      (*LCW*)
		    end (*indirect bit*);
		if V = 1 then					(*DATASTRCH*)
		    begin (*variable base*)
		    K := DISP;					(*DATASTRCH*)
		(* write in octal always*)                              (*29dec78 ALS*)
		    PRINT_SIGNED_OCTAL(K);
		    WRITE(OUTPUT,'(');
		    PRINTREG(REG);				(*DATASTRCH*)
		    WRITE(OUTPUT,')');
		    end (*variable base*)
		else
		    begin (*fixed base*)
		    K := ADDR;                           (*DATASTRCH*)    (*ALS*)
		    if (IPTR↑.OPCODE = XJSR)and(K <> 0) then
			K := K -(MAXS1ADDR +1);           (*DATASTRCH*)
(*A kludge to match the concretizer in handling negative ADDR value*)
		    PRINT_SIGNED_OCTAL(K);                          (*30DEC78 ALS*)
		    end (*fixed base*);
		WRITE(OUTPUT,CHR(124));                                     (*LCW*)
		if (OPNDREG=1) and (OPNDF=0) then
		    (*short-zero mode: no index to print*)
		else
		    begin (*print index*)
		    WRITE(OUTPUT,'(');                                      (*LCW*)
		    PRINTSHORTOP;
		    WRITE(OUTPUT,')');                                      (*LCW*)
		    K := S;					(*DATASTRCH*)
		    if K <> 0 then
			begin (*print shift*)
			WRITE(OUTPUT,'↑');                                  (*LCW*)
			PRINT_SIGNED_OCTAL(K);                      (*31DEC78 ALS*)
			end (*print shift*);
		    end (*print index*)
		end(*with OPND.XWD↑*)	    
	    end(*extended address*)
	end (*extended operand*)
    else
	begin (*short operand*)
	PRINTSHORTOP
	end (*short operand*)
    end (*PRINTOPERAND*);


    begin (*DISASSEMBLE*)
    CURS1OPC := IPTR↑.OPCODE;      				(*DATASTRCH*)
    XPTR1 := IPTR↑.INSTOPND1.XWD;				(*DATASTRCH*)
    XPTR2 := IPTR↑.INSTOPND2.XWD;				(*DATASTRCH*)
    case OPFORMAT[CURS1OPC] of

	VFAKEOP:
	    if not JUMPS_CONCRETIZED  then 		   (*15JAN79 PTZ...*)
		begin
		FORMFAKEINST(IPTR);				(*DATASTRCH*)
		PRINTLOC;
		PRINTIWORD;
		WRITE(OUTPUT,S1MNEM[CURS1OPC],' ');   (*PRINTOPCODE*)
		CVOS_10(SLOC,IPTR↑.FAKEOPND);		(*DATASTRCH*)
		J := 1;
		while SLOC[J] = ' ' do J := J+1;
		for I := J to 10 do WRITE(OUTPUT,SLOC[I]);
		WRITELN(OUTPUT)
		end
	    (*else ignore it*);				     (*...15JAN79 PTZ*)

	VTOP, VXOP, VSOP:
	    begin
	    if OPFORMAT[CURS1OPC] = VTOP then 
		FORMTOP(IPTR)					(*DATASTRCH*)
	    else if OPFORMAT[CURS1OPC] = VXOP then 
		FORMXOP(IPTR)					(*DATASTRCH*)
	    else if OPFORMAT[CURS1OPC] = VSOP then 
		FORMSOP(IPTR);					(*DATASTRCH*)
	    PRINTLOC;
	    PRINTIWORD;
	    WRITE(OUTPUT,S1MNEM[CURS1OPC],' ');	  (*PRINTOPCODE*)	(*ALS*)
	    if OPFORMAT[CURS1OPC] = VTOP then
		begin (*VTOP*)
		T := IPTR↑.T;					(*DATASTRCH*)
		if T = 1 then
		    begin (* OP1 = RTA, OP2 *)
		    PRINTOPERAND(IPTR↑.INSTOPND1);		(*DATASTRCH*)
		    WRITE(OUTPUT,',%RTA,');				(*LCW*)
		    PRINTOPERAND(IPTR↑.INSTOPND2);		(*DATASTRCH*)
		    end (* OP1 = RTA, OP2 *)
		else
		    begin
		    if	    T = 2 then WRITE(OUTPUT,'%RTA,')		(*LCW*)
		    else if T = 3 then WRITE(OUTPUT,'%RTB,')		(*LCW*)
		    (*else   T = 0*);
		    PRINTOPERAND(IPTR↑.INSTOPND1);		(*DATASTRCH*)
		    WRITE(OUTPUT,',');
		    PRINTOPERAND(IPTR↑.INSTOPND2);		(*DATASTRCH*)
		    end
		end (*VTOP*)
	    else
		begin (*VXOP, VSOP*)
		PRINTOPERAND(IPTR↑.INSTOPND1);			(*DATASTRCH*)
		WRITE(OUTPUT,',');
		PRINTOPERAND(IPTR↑.INSTOPND2);			(*DATASTRCH*)
		if OPFORMAT[CURS1OPC] = VSOP then
		    begin (*VSOP*)
		    WRITE(OUTPUT,',');                          (*LCW*)
		    if JUMPS_CONCRETIZED then			(*15JAN79 PTZ*)
			begin
			CVOS_10(SLOC,CURPC + WORDUNITS*IPTR↑.SKP);(*DATASTRCH*)
			J := 1;                                             (*LCW*)
			while SLOC[J] = ' ' do J := J+1;                    (*LCW*)
			for I := J to 10 do WRITE(OUTPUT,SLOC[I]);          (*LCW*)
			end
		    else
			PRINTPTRADDR(IPTR↑.DESTPTR);(*15JAN79 PTZ*)(*DATASTRCH*)
		    end (*VSOP*)
		end (*VXOP, VSOP*);
	    WRITELN(OUTPUT);
	    if XPTR2 <> nil then PRINTXW2;			(*3JAN79 ALS*)
	    if XPTR1 <> nil then PRINTXW1;			(*3JAN79 ALS*)
	    end (*VTOP, VXOP, VSOP*);

	VJOP:
	    begin
	    FORMJOP(IPTR);					(*DATASTRCH*)
	    PRINTLOC;
	    PRINTIWORD;
	    WRITE(OUTPUT,S1MNEM[CURS1OPC],' ');	  (*PRINTOPCODE*)	(*ALS*)
	    PRINTOPERAND(IPTR↑.INSTOPND1);			(*DATASTRCH*)
	    WRITE(OUTPUT,',');						(*LCW*)
	    if JUMPS_CONCRETIZED then
		begin
		if IPTR↑.PR = 1 then                            (*DATASTRCH*)
		    begin (*PC relative*)
		    CVOS_10(SLOC,CURPC + WORDUNITS*IPTR↑.J);    (*DATASTRCH*)
		    J := 1;                                                 (*LCW*)
		    while SLOC[J] = ' ' do J := J+1;                        (*LCW*)
		    for I := J to 10 do WRITE(OUTPUT,SLOC[I]);              (*LCW*)
		    end (*PC relative*)
		else
		    begin (*print OPND2*)
		    PRINTOPERAND(IPTR↑.INSTOPND2)               (*DATASTRCH*)
		    end (*print OPND2*)
		end
	    else
		begin
		PRINTOPERAND(IPTR↑.INSTOPND2);		(*28AUG79 PTZ*)
		PRINTPTRADDR(IPTR↑.DESTPTR);(*15JAN79 PTZ*)(*DATASTRCH*)
		end;
	    WRITELN(OUTPUT);
	    if XPTR2 <> nil then PRINTXW2;			(*3JAN79 ALS*)
	    if XPTR1 <> nil then PRINTXW1;			(*3JAN79 ALS*)
	    end (*VJOP*)

    end (*case*);
    CURPC := CURPC + IPTR↑.IWDS * WORDUNITS;
    end (*DISASSEMBLE*);
(** OBJECT_MODULE_SEGMENT_CLASS:	GEN_PSWITCH CODE_CONCRETIZER CONCPAS1 INSERTS1LOC JMPX_TO_JMPA_OPT **)
(**)

procedure GEN_PSWITCH;
     begin
     end;

procedure CODE_CONCRETIZER;
    (*Concretize the MAINCODE code in three passes.  On pass 1, insert
     fake S1LOC instructions at each jump or skip destination.	On
     pass 2, compute a final PC value as code is passed, filling the
     current PC value into each S1LOC instruction.  Also, fix up all
     PC relative extended operands by subtracting the PC value from
     their displacements.  On pass 3, fix up all jump and skip
     instructions by inserting final PC relative references.*)

    var
    IPTR :  AN_INSTREC;
    NXTPC, TPC, PASS2_MAXPC :  0..MAXS1LOC;
    PROC_WDS_REMOVED :  integer;				(*28APR79 PTZ*)

    procedure CONCPAS1;						(*PBK*)
	(* first pass over the code inserts S1LOC fake instructions
	   at the destination of each skip or jump.
	   peephole optimization of jumps to jumps is done during 
	   this pass. *)

	procedure INSERTS1LOC (JMPORSKPPTR : AN_INSTREC); 	(*PBK*)
						(*28APR79 PTZ*) (*DATASTRCH*)
	    (* This inserts an S1LOC fake instruction before the INSTREC
	       that is the destination of the jump or skip at JMPORSKPPTR.
	       If there was already an S1LOC there, change
	       ptrs so that each S1LOC marking this as a jmp or skp destination
	       will be pointed to by exactly one jmp or skp *)  (*28APR79 PTZ*)

	    var
		BEFORE, TPTR : AN_INSTREC;

	    begin
	     
	    BEFORE := JMPORSKPPTR↑.DESTPTR;
	    if BEFORE <> nil then
    (*          if BEFORE↑.OPCODE <> XS1LOC then                     PBK*)
		    begin
		    MAKE_NEWINSTREC(TPTR);
		    with TPTR↑ do
			begin
			OPCODE := XS1LOC;
			OPFMT := VFAKEOP;
			FAKEOPND := S1LOCUNDEF;
			IWDS := 0;
			NEXTPTR := BEFORE;
			PREVPTR := BEFORE↑.PREVPTR;
			BEFORE↑.PREVPTR := TPTR;
			if PREVPTR = nil then
			    MAINCODE.FIRST := TPTR
			else
			    PREVPTR↑.NEXTPTR := TPTR;
			end;
		    JMPORSKPPTR↑.DESTPTR := TPTR;
		    MAINCODE.NWORDS := MAINCODE.NWORDS + 1;
		    end (* if BEFORE <> nil then *);

	    end (* procedure INSERTS1LOC *);


	procedure JMPX_TO_JMPA_OPT ( INSTLOC : AN_INSTREC ); (*PBK*)  (*DATASTRCH*)
	    (* This procedure takes the jump instruction at INSTLOC
	       and follows the chain (if any) of its destination
	       through any JMPAs to make the destination the final
	       destination of the chain of JMPAs (if any).
	       This saves just a little bit of time, but it makes
	       the code more esthetically pleasing [huh?] *)

	    var
		JMP_TO_JMPA : boolean;
		JUMPDEST, DESTINST : AN_INSTREC;

	    begin
	    if INSTLOC↑.INSTOPND2.XWD = nil then
		begin
		JUMPDEST := INSTLOC↑.DESTPTR;
		repeat (* until not JMP_TO_JMPA *)
		    JMP_TO_JMPA := false;
		    if JUMPDEST <> nil then
			begin
			DESTINST := AFTER_FAKEOPS(JUMPDEST);
			if DESTINST <> nil then
			    begin
			    if DESTINST↑.OPCODE = XJMPA then
				begin
				JUMPDEST := DESTINST↑.DESTPTR;
				JMP_TO_JMPA := true;
				J_TO_J_CNT := J_TO_J_CNT + 1;
				end (* if DESTINST↑.OPCODE = XJMPA then *)
			    end (* if DESTINST <> nil then *)
			end (* if JUMPDEST <> nil then *)
		until not JMP_TO_JMPA;
		(* fix jump or skip destination of start of jump chain *)
		INSTLOC↑.DESTPTR := JUMPDEST;
		end;
	 (* else
		this JMPX has an extended destination word and hence is
		too complicated to chain - specifically it may be an
		indexed jump into a jump table (in this case the jumpdest
		ptr points to the first jump in the table - DON'T chain
		this since it won't in general actually execute through
		the first jump) *)
	    end (* JMPX_TO_JMPA_OPT *);


        begin (* CONCPAS1 *)			(*DATASTRCH*)

  	if TR_PEEPHOLE then					(*14JAN79 PTZ*)
	    begin
	    WRITELN(OUTPUT,'-----------------------------  ;START OF  ',
			   CURPROCXN.NAM,'  ',CURPROC);
	    WRITELN(OUTPUT,'before S1LOC insertion pass :');
	    WRITELN(OUTPUT,'-----------------------------');
	    PRINTMAINCODE					(*28APR79 PTZ*)
	    end;
  
	IPTR := MAINCODE.FIRST;

	while IPTR <> nil do
	    begin
	    if IPTR↑.OPFMT in [VJOP,VSOP] then
		begin
		if (IPTR↑.OPFMT = VJOP) and not NO_JMPX_TO_JMPA_FLG then
		    (* attempt to optimize jumps to JMPAs.
		       don't try to do skips to JMPAs, since
		       that would almost certainly make the skip
		       not reach, and we can't fix that up now. *)
		    JMPX_TO_JMPA_OPT(IPTR);
		INSERTS1LOC(IPTR);				(*28APR79 PTZ*)
		end (* if IPTR↑.OPFMT in [VJOP,VSOP] then *);
	    IPTR := IPTR↑.NEXTPTR
	    end (*while IPTR <> nil do*);

	if MAINCODE.LAST <> nil then
	    while MAINCODE.LAST↑.NEXTPTR <> nil do
		MAINCODE.LAST := MAINCODE.LAST↑.NEXTPTR;

        end (*CONCPAS1*);
(** OBJECT_MODULE_SEGMENT_CLASS:	PEEPHOLE_OPTIMIZER SKIP_JMPA_OPT INC_SKP_OPT **)
(**)

    procedure PEEPHOLE_OPTIMIZER (*(var CHANGES : boolean)*) ;	(*PTZ*)
						(*28APR79 PTZ*)	(*DATASTRCH*)
	var PREVIPTR : AN_INSTREC;
	    OLDNWORDS : integer;
	    CHANGES : boolean;

	procedure SKIP_JMPA_OPT (var SKIPPTR :  AN_INSTREC;  SKIPPC : integer);
								(*DATASTRCH*)
	    var JMPAPTR, L2PTR, TPTR, L1PTR :  AN_INSTREC;
		L2PC :  0..MAXS1LOC;
		JMPOFF :  integer;
		STILL_LOOKING :  boolean;

	    begin
	    JMPAPTR := AFTER_NONS1LOC_FAKEOPS(SKIPPTR↑.NEXTPTR);
	    if JMPAPTR <> nil then
		begin
		if (JMPAPTR↑.OPCODE = XJMPA)
		 and (JMPAPTR↑.PR <> 1) then
		    begin (*not in jump table*)
		    L1PTR := SKIPPTR↑.DESTPTR;
		    L2PTR := JMPAPTR↑.DESTPTR;
		    if not ((L1PTR↑.OPCODE = XS1LOC)
		      	    and (L2PTR↑.OPCODE = XS1LOC)) then
			ASSERTFAIL('SKIP_JMPA001');
		    TPTR := JMPAPTR↑.NEXTPTR;
		    STILL_LOOKING := true;
		    while (TPTR <> nil) and STILL_LOOKING do
			begin
			STILL_LOOKING := 
				(TPTR↑.OPFMT = VFAKEOP) and
				(TPTR <> L1PTR);
			if STILL_LOOKING then
			    TPTR := TPTR↑.NEXTPTR
			end;
		    if TPTR = L1PTR then
			begin  (*the SKP skips around the JMPA*)
			L2PC := L2PTR↑.FAKEOPND;
			if L2PC <> S1LOCUNDEF then
			    begin (*backward skip or ≥ 2nd pass*)
			    JMPOFF := (L2PC - SKIPPC) div WORDUNITS;
			    if JMPOFF > 0 then
(*28AUG79 PTZ*)			JMPOFF := JMPOFF - JMPAPTR↑.IWDS
				          - (OLDNWORDS - MAINCODE.NWORDS)
			    end
			else
			    begin (*forward skip: 1st pass only*)
(*28AUG79 PTZ*)		    JMPOFF := SKIPPTR↑.IWDS;
			    TPTR := JMPAPTR↑.NEXTPTR;
			    while (JMPOFF <= MAXSKPOFFSET) and (TPTR <> L2PTR)
			     and (TPTR <> nil) do
				begin
(*1OCT79 PTZ*)			JMPOFF := JMPOFF 
(*in case TPTR↑.OPFMT = VJOP*)    + INSTR_WORDS(TPTR,SKIPPC + JMPOFF*WORDUNITS);
				TPTR := TPTR↑.NEXTPTR
				end;
			    end;
			if (MINSKPOFFSET <= JMPOFF)
			 and (JMPOFF <= MAXSKPOFFSET) then
			    begin
(*    SKP.COND.X  Y,Z,L1 *) JMPAS_REMOVED_FROM_SKIPS :=
(*    JMPA        L2	 *)			 JMPAS_REMOVED_FROM_SKIPS + 1;
(*L1: S1LOC		 *) SKIPPTR↑.OPCODE := INVERSE_SKIP[SKIPPTR↑.OPCODE];
(* (MINSKPOFFSET<=L2-SKP *) SKIPPTR↑.DESTPTR := L2PTR;
(*       <=MAXSKPOFFSET) *) 
(*	=>		 *) DELETE_INSTR(JMPAPTR);
(* SKP.invCOND.X  Y,Z,L2 *) DELETE_INSTR(L1PTR)
			   (* There is 1 S1LOC for each time a place is used as a
			      destination, so we can optimize across the boundary 
			      when the last one goes away *)
  			    end
			end (*if TPTR = L1PTR then*)
		    end
		end (*if JMPAPTR <> nil then*)
	    end (*SKIP_JMPA_OPT*);


	procedure INC_SKP_OPT (var INCDECPTR : AN_INSTREC);   (*28JUN79 PTZ*)
								(*DATASTRCH*)
	    var SKPJMPAPTR : AN_INSTREC;
		SKPJMPAOPC, INCDECOPC, ISKPOPC : S1OPCODE;

	    begin
	    SKPJMPAPTR := AFTER_NONS1LOC_FAKEOPS(INCDECPTR↑.NEXTPTR);
	    if SKPJMPAPTR <> nil then
		begin
		if INCDECPTR↑.OPCODE = XINC_S then
		    ISKPOPC := ISKPJMPA_OPCODE[SKPJMPAPTR↑.OPCODE]
		else
		    begin
		    if not (INCDECPTR↑.OPCODE = XDEC_S) then
			ASSERTFAIL('INC_SKP  001');
		    ISKPOPC := DSKPJMPA_OPCODE[SKPJMPAPTR↑.OPCODE]
		    end;
		if (ISKPOPC <> XILLEGAL) 
		  and (S1OPNDS_EQUAL(INCDECPTR,OPND1NUM,INCDECPTR,OPND2NUM))
		then
		    begin
		    if SKPJMPAPTR↑.OPCODE = XJMPA then
			begin
		        if SKPJMPAPTR↑.PR <> 1 then
			    begin  (*not in jump table*)
(* INCorDEC.S   Y,Y   *)    INC_SKP_COLLAPSE[1] := INC_SKP_COLLAPSE[1] + 1;
(* JMPA         L     *)    SKPJMPAPTR↑.OPCODE := ISKPOPC;
(*	=>	      *)
(* IorDJMPA     Y,L   *)    INSERT_OPND1(SKPJMPAPTR,INCDECPTR↑.INSTOPND1);
			    DELETE_INSTR(INCDECPTR);
			    INCDECPTR := SKPJMPAPTR
			    end
			end (*XJMPA*)
		    else
			begin (*VSOP*)
			if not (SKPJMPAPTR↑.OPFMT = VSOP) then
			    ASSERTFAIL('INC_SKP  002');
			if S1OPNDS_EQUAL(INCDECPTR,OPND1NUM,
					 SKPJMPAPTR,OPND1NUM) then
			    begin
(* INCorDEC.S   Y,Y   *)    INC_SKP_COLLAPSE[2] := INC_SKP_COLLAPSE[2] + 1;
(* SKP.ACOND.S  Y,Z,L *)    SKPJMPAPTR↑.OPCODE := ISKPOPC;
(*	=>    	      *)    DELETE_INSTR(INCDECPTR);
(* IorDSKP.ACOND Y,Z,L*)    INCDECPTR := SKPJMPAPTR
			    end
			else if S1OPNDS_EQUAL(INCDECPTR,OPND1NUM,
					      SKPJMPAPTR,OPND2NUM) then
			    begin
(* INCorDEC.S   Y,Y   *)    INC_SKP_COLLAPSE[3] := INC_SKP_COLLAPSE[3] + 1;
(* SKP.ACOND.S  Z,Y,L *)    SKPJMPAPTR↑.OPCODE := REVERSE_OP[ISKPOPC];
(*	=>	      *)    SWAP_OPERANDS(SKPJMPAPTR);
(* IorDSKP.revACOND   *)    DELETE_INSTR(INCDECPTR);
(*              Y,Z,L *)    INCDECPTR := SKPJMPAPTR
			    end
			end (*VSOP*)
		    end
		end
	    end (*INC_SKP_OPT*);
(** OBJECT_MODULE_SEGMENT_CLASS:	COLLAPSE_MOV_OPT **)
(**)

	procedure COLLAPSE_MOV_OPT (var OPPTR :  AN_INSTREC);	(*DATASTRCH*)

	    var MOV_OPND1, MOV_OPND2, T :  integer;
		MOVOPC, OPCODE :  S1OPCODE;
		MOVPTR : AN_INSTREC;
		MOV_PRECISION : S1PRECISION;

	    begin
	    MOVPTR := AFTER_NONS1LOC_FAKEOPS(OPPTR↑.NEXTPTR);
	    if MOVPTR <> nil then
		begin
		MOVOPC := MOVPTR↑.OPCODE;
		MOV_PRECISION := S1ILLEGAL;
		if MOVOPC = XMOV_S_S then   	 MOV_PRECISION := S1S
		else if MOVOPC = XMOV_D_D then   MOV_PRECISION := S1D
		else if MOVOPC = XMOV_Q_Q then   MOV_PRECISION := S1Q
		else if MOVOPC = XMOV_H_H then   MOV_PRECISION := S1H;
		MOV_OPND2 := S1OPND_TEMPLOC(MOVPTR↑.INSTOPND2);
		if    (MOV_OPND2 >= 0) 
		  and (DEST_PRECISION[OPPTR↑.OPCODE] = MOV_PRECISION)
		  and  PEEP_LOC_IS_FREE(MOVPTR↑.NEXTPTR,MOV_OPND2)
		then
		    begin
		    (*We now know that the source of the MOV.X.X is
		      no longer going to be used, and that the instruction
		      preceding the MOV.X.X is a collapsible one.
		      Now look for certain patterns in the collapsible inst*)
		    if OPPTR↑.OPFMT = VXOP then
			begin
			if S1OPND_TEMPLOC(OPPTR↑.INSTOPND1) = MOV_OPND2 then
			    begin
(* XOP.X.W   TREG,Y  *)	    MOV_COLLAPSE[1] := MOV_COLLAPSE[1] + 1;
(* MOV.X.X   Z,TREG  *)	    INSERT_OPND1(OPPTR,MOVPTR↑.INSTOPND1);
(*	=>	     *)     DELETE_INSTR(MOVPTR)
(* XOP.X.W   Z,Y     *)     end
			end (*XOP*)
		    else
			begin (*TOP*)
			if not (OPPTR↑.OPFMT = VTOP) then
			    ASSERTFAIL('COLLAPSE 001');
			case OPPTR↑.T of

			0:  if S1OPND_TEMPLOC(OPPTR↑.INSTOPND1) = MOV_OPND2 then
				begin
				if S1OPNDS_EQUAL(OPPTR,OPND2NUM,
						 MOVPTR,OPND1NUM) then
				    begin
(* TOP.X     TREG,Y          *)     MOV_COLLAPSE[2] := MOV_COLLAPSE[2] + 1;
(* MOV.X.X   Y,TREG	     *)	    INVERT_OPCODE(OPPTR);
(*	=>		     *)	    SWAP_OPERANDS(OPPTR);
(* reverseTOP.X   Y,TREG     *)	    DELETE_INSTR(MOVPTR)
				    end
				else if MOV_OPND2 = S1RTA then
				    begin
(* TOP.X     RTA,Y	     *)	    MOV_COLLAPSE[3] := MOV_COLLAPSE[3] + 1;
(* MOV.X.X   Z,RTA	     *)	    INSERT_OPND1(OPPTR,MOVPTR↑.INSTOPND1);
(*	=>		     *)     OPPTR↑.T := 1;
(* TOP.X     Z,RTA,Y	     *)     DELETE_INSTR(MOVPTR)
				    end
				else if S1OPND_TEMPLOC(OPPTR↑.INSTOPND2) 
					 = S1RTA then
				    begin
(* TOP.X     TREG,RTA	     *)	    MOV_COLLAPSE[4] := MOV_COLLAPSE[4] + 1;
(* MOV.X.X   Z,TREG	     *)	    INVERT_OPCODE(OPPTR);
(*	=>		     *)	    SWAP_OPERANDS(OPPTR);
(* reverseTOP.X   Z,RTA,TREG *)	    INSERT_OPND1(OPPTR,MOVPTR↑.INSTOPND1);
				    OPPTR↑.T := 1;
				    DELETE_INSTR(MOVPTR)
				    end
				else if S1OPND_TEMPLOC(MOVPTR↑.INSTOPND1)
					= S1RTA then
				    begin
(* TOP.X     TREG,Z	    *)	    MOV_COLLAPSE[5] := MOV_COLLAPSE[5] + 1;
(* MOV.X.X   RTA,TREG	    *)      OPPTR↑.T := 2;
(*	=>		    *)      DELETE_INSTR(MOVPTR)
(* TOP.X     RTA,TREG,Z     *)      end
				else if S1OPND_TEMPLOC(MOVPTR↑.INSTOPND1)
					= S1RTB then
				    begin
(* TOP.X     TREG,Z	    *)	    MOV_COLLAPSE[6] := MOV_COLLAPSE[6] + 1;
(* MOV.X.X   RTB,TREG	    *)      OPPTR↑.T := 3;
(*	=>		    *)      DELETE_INSTR(MOVPTR)
(* TOP.X     RTB,TREG,Z     *)      end
				end;

			1:  if S1OPND_TEMPLOC(OPPTR↑.INSTOPND1) = MOV_OPND2 then
				begin
				if S1OPNDS_EQUAL(OPPTR,OPND2NUM,
						 MOVPTR,OPND1NUM) then
				    begin
(* TOP.X     TREG,RTA,Y     *)	    MOV_COLLAPSE[7] := MOV_COLLAPSE[7] + 1;
(* MOV.X.X   Y,TREG	    *)	    INVERT_OPCODE(OPPTR);
(*	=>		    *)	    OPPTR↑.T := 0;
(* reverseTOP.X   Y,RTA     *)	    SWAP_OPERANDS(OPPTR);      (*gives Y,TREG*)
				    OPPTR↑.INSTOPND2.F := S1RTA;  (*gives Y,RTA*)
				    DELETE_INSTR(MOVPTR)
				    end
				else
				    begin
(* TOP.X     TREG,RTA,Y    *)	    MOV_COLLAPSE[8] := MOV_COLLAPSE[8] + 1;
(* MOV.X.X   Z,TREG	   *)	    INSERT_OPND1(OPPTR,MOVPTR↑.INSTOPND1);
(*	=>		   *)       DELETE_INSTR(MOVPTR)
(* TOP.X     Z,RTA,Y	   *)       end
				end;

			2,3:
			    if ((OPPTR↑.T=2) and (MOV_OPND2=S1RTA))
			      or ((OPPTR↑.T=3) and (MOV_OPND2=S1RTB)) then
				begin
				if S1OPNDS_EQUAL(OPPTR,OPND1NUM,
						 MOVPTR,OPND1NUM) then
				    begin
(* TOP.X     RTAorRTB,Y,Z  *)	    MOV_COLLAPSE[9] := MOV_COLLAPSE[9] + 1;
(* MOV.X.X   Y,RTAorRTB    *)	    OPPTR↑.T := 0;
(*	=>		   *)	    DELETE_INSTR(MOVPTR)
(* TOP.X     Y,Z	   *)       end
				else if S1OPNDS_EQUAL(OPPTR,OPND2NUM,
						      MOVPTR,OPND1NUM) then
				    begin
(* TOP.X     RTAorRTB,Z,Y  *)	    MOV_COLLAPSE[10] := MOV_COLLAPSE[10] + 1;
(* MOV.X.X   Y,RTAorRTB    *)	    INVERT_OPCODE(OPPTR);
(*	=>		   *)	    OPPTR↑.T := 0;
(* reverseTOP.X   Y,Z	   *)	    SWAP_OPERANDS(OPPTR);
				    DELETE_INSTR(MOVPTR)
				    end
				else if MOV_OPND2 = S1RTB then
				    begin
				    if S1OPND_TEMPLOC(OPPTR↑.INSTOPND2)
						= S1RTA then
					begin
(* TOP.X     RTB,Y,RTA     *)           MOV_COLLAPSE[11] := MOV_COLLAPSE[11] + 1;
(* MOV.X.X   Z,RTB         *)		INVERT_OPCODE(OPPTR);
(*	=>		   *)		SWAP_OPERANDS(OPPTR);
(* reverseTOP.X   Z,RTA,Y  *)		INSERT_OPND1(OPPTR,MOVPTR↑.INSTOPND1);
					OPPTR↑.T := 1;
					DELETE_INSTR(MOVPTR)
					end
				    else if S1OPND_TEMPLOC(OPPTR↑.INSTOPND1)
						= S1RTA then
					begin
(* TOP.X     RTB,RTA,Y     *)		MOV_COLLAPSE[12] := MOV_COLLAPSE[12] + 1;
(* MOV.X.X   Z,RTB	   *)		INSERT_OPND1(OPPTR,MOVPTR↑.INSTOPND1);
(*	=>		   *)		OPPTR↑.T := 1;
(* TOP.X     Z,RTA,Y	   *)		DELETE_INSTR(MOVPTR)
					end
				    else if S1OPND_TEMPLOC(MOVPTR↑.INSTOPND1)
						= S1RTA then
					begin
(* TOP.X     RTB,Y,Z       *)		MOV_COLLAPSE[13] := MOV_COLLAPSE[13] + 1;
(* MOV.X.X   RTA,RTB       *)		OPPTR↑.T := 2;
(*	=>		   *)		DELETE_INSTR(MOVPTR)
(* TOP.X     RTA,Y,Z	   *)		end
				    end
				else if MOV_OPND2 = S1RTA then
				    begin
				    if S1OPND_TEMPLOC(MOVPTR↑.INSTOPND1)
						= S1RTB then
					begin
(* TOP.X     RTA,Y,Z       *)		MOV_COLLAPSE[14] := MOV_COLLAPSE[14] + 1;
(* MOV.X.X   RTB,RTA       *)		OPPTR↑.T := 3;
(*	=>		   *)		DELETE_INSTR(MOVPTR)
(* TOP.X     RTB,Y,Z	   *)		end
				    end
				end
			    end (*case*)
			end (*TOP*)
		    end
		end (*MOVPTR <> nil*)
	    end (*COLLAPSE_MOV_OPT*);
(** OBJECT_MODULE_SEGMENT_CLASS:	PEEPHOLE_OPTIMIZER **)
(**)

	begin (*PEEPHOLE_OPTIMIZER*)				(*DATASTRCH*)

	(* The first pass of the peephole optimizer removes or simplifies
	   any instructions that it can *)

	if TR_PEEPHOLE then					(*14JAN79 PTZ*)
	    begin
	    WRITELN(OUTPUT);
	    WRITELN(OUTPUT,'-------------------------');
	    WRITELN(OUTPUT,'before peephole pass  1 :');
	    WRITELN(OUTPUT,'-------------------------');
	    PRINTMAINCODE					(*28APR79 PTZ*)
	    end;

	OLDNWORDS := MAINCODE.NWORDS;				(*28AUG79 PTZ*)
	IPTR := MAINCODE.FIRST;
	CURPC := SEG_EP_RELPC;

	while IPTR <> nil do
	    begin
	    if COLLAPSIBLE_OP[IPTR↑.OPCODE] and not NO_COLLAPSE_MOV_FLG then
		COLLAPSE_MOV_OPT(IPTR);		(*can modify IPTR*)
	    if ((IPTR↑.OPCODE = XINC_S) or (IPTR↑.OPCODE = XDEC_S))
	      and not NO_INC_SKP_FLG then
		INC_SKP_OPT(IPTR);	(*can modify IPTR*)
	    IPTR := IPTR↑.NEXTPTR;
	    end (*while IPTR <> nil do*);

	PROC_WDS_REMOVED := PROC_WDS_REMOVED + (OLDNWORDS - MAINCODE.NWORDS);
								(*28AUG79 PTZ*)

	(* The rest of the peephole optimizer - at most MAXPEEPASSES -
	   does a straightforward collapse of skips around JMPAs that
	   are short enough to be a skip alone.  A small amount of testing
	   shows that the first pass gets about 90 percent of the cases
	   and the second pass gets a few percent more, etc.

	   We don't combine this optimization with the previous group
	   because keeping track of the PC while deleting instructions
	   and pieces of instructions is difficult *)

	PASS2_MAXPC := SEG_EP_RELPC + WORDUNITS*MAINCODE.NWORDS;
	CHANGES := true;
	PEEP_PASSES := 0;

	while CHANGES and (PEEP_PASSES < MAXPEEP_PASSES) do
	    begin
	    if TR_PEEPHOLE then                                     (*14JAN79 PTZ*)
		begin
		WRITELN(OUTPUT);
		WRITELN(OUTPUT,'-------------------------');
		WRITELN(OUTPUT,'before peephole pass ',PEEP_PASSES+2:2,':');
		WRITELN(OUTPUT,'-------------------------');
		PRINTMAINCODE					(*28APR79 PTZ*)
		end;

	    OLDNWORDS := MAINCODE.NWORDS;
	    IPTR := MAINCODE.FIRST;
	    CURPC := SEG_EP_RELPC;

	    while IPTR <> nil do
		begin
		if IPTR↑.OPFMT = VFAKEOP then
		    begin
		    if IPTR↑.OPCODE = XS1LOC then
			IPTR↑.FAKEOPND := CURPC
		    end
		else
		    begin
		    if (IPTR↑.OPFMT = VSOP) and not NO_SKIP_JMPA_FLG then
			SKIP_JMPA_OPT(IPTR,CURPC)
		    end;
		CURPC := CURPC + INSTR_WORDS(IPTR,CURPC)*WORDUNITS;
		IPTR := IPTR↑.NEXTPTR
		end (*while IPTR <> nil do*);

	    CHANGES := (OLDNWORDS <> MAINCODE.NWORDS);
	    PASS2_MAXPC := CURPC;
	    PROC_WDS_REMOVED := PROC_WDS_REMOVED + (OLDNWORDS - MAINCODE.NWORDS);
								    (*28AUG79 PTZ*)
	    PEEP_PASSES := PEEP_PASSES + 1
	    end;
	end (*PEEPHOLE_OPTIMIZER*);
(** OBJECT_MODULE_SEGMENT_CLASS:	CONCPAS3 PASS3PCRELFIX INSERT_NOP **)
(**)

    procedure CONCPAS3;				(*PTZ*)		(*DATASTRCH*)

        var SKPOFF :  MINSKPOFFSET..MAXSKPOFFSET;
	    JMPOFF :  integer;
	    TOPND :  OPERAND;
	    NXTIPTR, LASTPTR, JUMPSKIPDEST : AN_INSTREC;
	    FORCE2 :  boolean;
	    SAVEIWDS : IWDRNG;					(*28AUG79 PTZ*)

	procedure PASS3PCRELFIX (var OPND : INSTOPND);		(*DATASTRCH*)
	    (*Examine the extended non-constant S1 operand in INSTOPND.
	     If it is PC relative, fix it up by subtracting
	     the current PC value from the displacement.*)

	    var VBIT :  BIT;

	    begin
	    if not (OPND.XWD <> nil) then
                ASSERTFAIL('PASS3PCRE001');
	    with OPND.XWD↑ do
		begin
		VBIT := V;
		if ((OPND.REG = 0) and (OPND.F = S1RPC))
		  or ((V = 1) and (REG = S1RPC)) then
		    if V = 1 then
			DISP := DISP - CURPC
		    else
			if ADDR >= CURPC then
			    ADDR := ADDR - CURPC
			else
			    ADDR := ADDR - CURPC + (MAXS1ADDR+1)
		end
	    end (*PASS3PCRELFIX*);

	procedure INSERT_NOP;
	    (*Insert a single word no-op in the code immediately following
	     the word at LASTPTR, updating NXTPC (and MAINCODE.NWORDS).*)

	    var OPND :  OPERAND;

	    begin
	    INSERTXOP(LASTPTR,XNOP,UNUSED_OP,UNUSED_OP);              (*LCW*)
	    NXTPC := NXTPC + WORDUNITS
	    end (*INSERT_NOP*);


	begin (*CONCPAS3*)					(*DATASTRCH*)

	if TR_PEEPHOLE then                                     (*14JAN79 PTZ*)
	    begin
	    WRITELN(OUTPUT);
	    WRITELN(OUTPUT,'-------------------------');
	    WRITELN(OUTPUT,'before final concretizer:');
	    WRITELN(OUTPUT,'-------------------------');
	    PRINTMAINCODE					(*28APR79 PTZ*)
	    end;

	IPTR := MAINCODE.FIRST;
	CURPC := SEG_EP_RELPC;

	while IPTR <> nil do
	    begin
	    with IPTR↑ do
		begin
		NXTIPTR := NEXTPTR;	(*in case we insert some NOPs*)
		NXTPC := CURPC;
		SAVEIWDS := IWDS;				(*28AUG79 PTZ*)
		if OPFMT = VFAKEOP then
		    begin
		    if OPCODE = XS1LOC then
			begin
			if not (FAKEOPND = CURPC) then
			    ASSERTFAIL('CODE_CONC002')
			end
		    end
		else (*not VFAKEOP*)
		    begin
		    NXTPC := NXTPC + WORDUNITS;
		    if INSTOPND1.XWD <> nil then
			begin (*extended OPND1*)
			NXTPC := NXTPC + WORDUNITS;
			if not
			    ((INSTOPND1.F > 0) and (INSTOPND1.REG = 1))
			then
			    PASS3PCRELFIX(INSTOPND1);
			end;
		    if INSTOPND2.XWD <> nil then
			begin (*extended OPND2*)
			NXTPC := NXTPC + WORDUNITS;
			if not
			    ((INSTOPND2.F > 0) and (INSTOPND2.REG = 1))
			then
			    PASS3PCRELFIX(INSTOPND2);
			end;
		    if OPFMT = VSOP then
			begin (*any VSOP*)
			JUMPSKIPDEST := DESTPTR;
			if JUMPSKIPDEST <> nil then
			    begin
			    if not (JUMPSKIPDEST↑.OPCODE = XS1LOC) then
				ASSERTFAIL('CODE_CONC003');
			    TPC := JUMPSKIPDEST↑.FAKEOPND;
			    if not (TPC <> S1LOCUNDEF) then
				ASSERTFAIL('CODE_CONC004');
			    SKPOFF := (TPC-CURPC) div WORDUNITS;
			    if not ((MINSKPOFFSET<=SKPOFF)
				    and (SKPOFF<=MAXSKPOFFSET)) then
				ASSERTFAIL('CODE_CONC005');
			    SKP := SKPOFF
			    end
			end (*any VSOP*)
		    else if OPFMT = VJOP then
			begin (*any VJOP*)
			LASTPTR := IPTR;
			JUMPSKIPDEST := DESTPTR;
			FORCE2 := (PR = 1)    (*force two-word jump*);
			if JUMPSKIPDEST = nil then
			    (*no JUMPDEST: leave alone except FORCE2*)
			    PR := 0
			else
			    begin
			    if not (JUMPSKIPDEST↑.OPCODE = XS1LOC) then
				ASSERTFAIL('CODE_CONC006');
			    TPC := JUMPSKIPDEST↑.FAKEOPND;
			    if not (TPC <> S1LOCUNDEF) then
				ASSERTFAIL('CODE_CONC007');
			    JMPOFF := (TPC-CURPC) div WORDUNITS;
			    if (MINJPROFFSET<=JMPOFF) and (JMPOFF<=MAXJPROFFSET)
			      and (INSTOPND2.XWD = nil) then
				begin (*PR-style jump*)
				PR := 1;
				J := JMPOFF
				end (*PR-style jump*)
			    else
				begin (*non PR-style jump*)
				PR := 0;
				if INSTOPND2.XWD = nil then
				    begin (*build an extended OPND2*)
				    if not (MAINCODE.NWORDS > MAXJPROFFSET) then
					ASSERTFAIL('CODE_CONC010');
				    NXTPC := NXTPC + WORDUNITS;
    (*EJG 17JAN79*)                 XTNDED_REGDISP_OPERAND(TOPND, S1RPC, -CURPC);
				    new(INSTOPND2.XWD);
                                    INSTOPND2.XWD↑ := TOPND.XW;
(*should have already been 	    IWDS := IWDS + 1;
  counted...	28AUG79 PTZ	    MAINCODE.NWORDS := MAINCODE.NWORDS + 1*)
				    end (*build an extended OPND2*);
				INSTOPND2.XWD↑.DISP := INSTOPND2.XWD↑.DISP + TPC
				end (*non PR-style jump*);
			    end (*valid JUMPDEST*);
			if FORCE2 then
			    begin (*force two-word jump*)
			    while NXTPC-CURPC < 2*WORDUNITS do
				begin
				INSERT_NOP;
				IWDS := IWDS - 1;  (*this used to be counted in*)
						   (*the JOP instr*) (*28AUG79 PTZ*)
				end;
			    if not (NXTPC-CURPC = 2*WORDUNITS) then
				ASSERTFAIL('CODE_CONC008')
					(*else was already > 2 words*)
			    end (*force two-word jump*)
			else
			    begin (*normal jump*)
			    if IWDS <> (NXTPC - CURPC) div WORDUNITS then
				begin
				if (PR = 1) and (MAINCODE.NWORDS > MAXJPROFFSET)
				  then                                
				    (*We assumed extended OPND2,
				     but managed to emit PR-style -
				     so insert NOP to keep PC straight*)
				    begin
				    INSERT_NOP;
				    IWDS := IWDS - 1; (*this used to be counted in*)
						   (*the JOP instr*) (*28AUG79 PTZ*)
				    end;
				end 
			    end (*normal jump*)
			end (*any VJOP*)
		    end (*not VFAKEOP*);
		if not (CURPC + SAVEIWDS * WORDUNITS = NXTPC) then   (*28AUG79 PTZ*)
		    ASSERTFAIL('CODE_CONC011');
		end (*with IPTR↑ do*);
	    IPTR := NXTIPTR;
	    CURPC := NXTPC
	    end (*while IPTR <> nil do*);

        if not (PASS2_MAXPC = CURPC) then ASSERTFAIL('CODE_CONC009');

	end (*CONCPAS3*);


    begin (*CODE_CONCRETIZER*)				(*28APR79 PTZ...*)
    PROC_WDS_REMOVED := 0;

    CONCPAS1;

    PEEPHOLE_OPTIMIZER;

    CONCPAS3;
    JUMPS_CONCRETIZED := true;

    INSTR_WDS_REMOVED := INSTR_WDS_REMOVED + PROC_WDS_REMOVED;
    end (*CODE_CONCRETIZER*);				(*...28APR79 PTZ*)
(** OBJECT_MODULE_SEGMENT_CLASS:	INIT_SEGMENT GEN_SEGMENT FIXDISP OPEN_SEGMENT CLOSE_SEGMENT CLEAROUT_TXTBUF OPEN_TXT CLOSE_TXT OUT_TXT **)
(**)

procedure INIT_SEGMENT;

    var R :  S1REGISTER;
	G :  S1GBL;
	H :  integer;
	S1X :  S1Q..S1D;

    begin
    NEW(OLDNP);
    MAINCODE := EMPTYINSTLIST;					(*DATASTRCH*)
    ALL_CODE_EMITTED := false;					(*DATASTRCH*)
    JUMPS_CONCRETIZED := false;
    MAKE_NEWINSTREC(NEWINSTREC);				(*DATASTRCH*)
    STRINGAREA := EMPTYCODELIST;
    NXTSTRDISP := 0;
    STRINGFIXLIST := EMPTYOPNDXWORDFIXLIST;			(*DATASTRCH*)
    TOP := BOT-1;
    for R := FIRSTS1REG to LASTS1REG do
	begin
	RISFREE[R] := true;
	RPWORD[R] := RSINGLE;						(*PBK*)
	end;
    for G := FIRSTS1GBL to LASTS1GBL do
	begin
	GISFREE[G] := true;
	end;
    MINTMPS1REG := MINPARS1REG;
    for H := 0 to LBLHTSIZEM1 do
	LBLHASHTAB[H] := nil;
    EVALSAVE.SIZE := 0;
    EVALSAVE.FIXLIST := EMPTYOPND2FIXLIST;			(*DATASTRCH*)
    EVALSAVE.NEGFIXLIST := EMPTYOPND2FIXLIST;			(*DATASTRCH*)
    NEG_SHIFT_FIXLIST := EMPTYOPND2FIXLIST;			(*DATASTRCH*)
    MSTTOP := 0;
    REALTBL := EMPTYCODELIST;
    SETTBL := EMPTYCODELIST;
    LOCTBL := EMPTYCODELIST;
    REALFIXLIST := EMPTYOPNDXWORDFIXLIST;			(*DATASTRCH*)
    SETFIXLIST := EMPTYOPNDXWORDFIXLIST;			(*DATASTRCH*)
    PROCTBL.NPROCS := 0;
    STACKFRAME.SIZE := 0;			(*als/peg 25jul79..*)
    STACKFRAME.FIXLIST := EMPTYOPND2FIXLIST;			(*DATASTRCH*)
    STACKFRAME.NEGFIXLIST := EMPTYOPND2FIXLIST;	(*...als/peg 25jul79*)(*DATASTRCH*)
    MSTSTK[MSTTOP].EVALSAVESTART := 0;
    BOUNDTBL := EMPTYCODELIST;
    BOUNDFIXLIST := EMPTYOPNDXWORDFIXLIST;			(*DATASTRCH*)
    PROCTBL.FIRST := nil;
    end (*INIT_SEGMENT*);



procedure GEN_SEGMENT;

    const
    MAXTXTBUFNWORDS = 4;   (*for TXT records to fit in 80 columns*)

    var
    PTR :  A_CODEREC;						(*DATASTRCH*)
    OXPTR : AN_OPNDXWORDREC;					(*DATASTRCH*)
    O2PTR : AN_OPND2REC;					(*DATASTRCH*)
    IPTR, NXTIPTR : AN_INSTREC;					(*DATASTRCH*)
    OPLOC : AN_OPERANDXWORD;					(*DATASTRCH*)
    VAL, DSP :	integer;
    I :  0..LBLHTSIZEM1;
    LPTR :  A_LBLHASHENT;
    PPTR :  A_PROCENT;
    ASMPC, NXTPC, MAXPC :  integer;
    PITPC :  integer;  (*address of PIT in segment*)
    S1PC :  integer;
    NREF, INX :  integer;
    CURS1OPC :	S1OPCODE;
    ICW, W, W1, W2 :  S1WORD;
    TXTBUF : array [1..MAXTXTBUFNWORDS] of S1WORD;
    TXTBUFNWORDS :  0..MAXTXTBUFNWORDS;
    TXTBUFFSTADR :  S1RELADR;
    TXTBUFNXTADR :  S1RELADR;
    TADR : integer;						(*31AUG79 PTZ*)
    SSTR : CHAR4;
    SLOC : CHAR10;
    SWORD :  CHAR12;
    S1X :  S1Q..S1D;
    INSTPI : INSTREC_PTRINT;                                	(*31AUG79 PTZ...*)
    NEWNP : AN_INSTREC;
    HEAPTOP, HEAPBOTTOM : integer;				(*...31AUG79 PTZ*)

    procedure DISASM(NXTCP : INTEGER; PTR : A_CODEREC);		(*28DEC78 ALS*)
	begin
	CVOS_10(SLOC,NXTPC);
	WRITE(OUTPUT,SLOC,' :  ');
	ICW := PTR↑.CODEWORD;
	CVOS_S1WORD_12(SWORD,ICW);
	WRITE(OUTPUT,SWORD,'  ');
	end (* DISASM *);

    procedure DISASM2(PTR : A_CODEREC);				(*28DEC78 ALS*)
	var
	K, KWID : INTEGER;
	begin
	ICW := PTR↑.CODEWORD;
	K := GETFIELD(ICW,WORDBITS-(BITS_ON_COMP_MACH-1),
		                    BITS_ON_COMP_MACH - 1);
	KWID := FLDW(K);
	WRITE(OUTPUT,K:KWID,'.');
	WRITELN(OUTPUT);
	end (* DISASM2 *);

	
    procedure FIXDISP(WORDLOC :  AN_OPERANDXWORD; FIXVAL :  integer);(*DATASTRCH*)
	(*Fix up the extended word addressed by WORDLOC by adding the
	 FIXVAL to the displacement.*)

	var DSP :  integer;

	begin
	DSP := WORDLOC↑.DISP;					(*DATASTRCH*)
	DSP := DSP + FIXVAL;
	if (DSP > MAXS1DISP) or (DSP < MINS1DISP) then
	    ERROR(WINVALID_DISPLACEMENT)
	else
	    WORDLOC↑.DISP := DSP;				(*DATASTRCH*)
	end (*FIXDISP*);


    procedure OPEN_SEGMENT(NESD, NTXT, NESR, NRLD :  integer);
	(*Prepare to output the segment.  NESD is the number of
	 external symbols which will be defined.  NTXT is the number
	 of words of TXT which will be output.	NESR is the number of
	 external symbols which will be referenced.  NRLD is the
	 number of words which will be relocated.  If any of these
	 parameters is not known exactly, specify -1.*)

	begin
	(*No-op for now with the intermediate loader format*)
	end (*OPEN_SEGMENT*);


    procedure CLOSE_SEGMENT;
	(*Close segment output.*)

	begin
	(* The following SIN record should be output when S-1 runtimes
	   exist for finding compilation date and time - see LDI-5:
  	WRITELN(PRR,'SIN COMPILER             0 ',compilation date,' ',
		compilation time,' ',SOPA_NAME:8,' ',SOPA_VERSION:2,
		' ',SOPA_MODLEVEL:2);  			*)	(*23JUL79 PTZ*)
	WRITELN(PRR,'EOM ',CURPROCXN.NAM,' WRITER-ID: ',
		SOPA_ID); 	(*temporarily*)			(*23JUL79 PTZ*)
	end (*CLOSE_SEGMENT*);


    procedure CLEAROUT_TXTBUF;
	(*Clear out the TXTBUF by outputting a TXT record if any text
	 is contained therein. Count the words output.*)		(*LCW*)

	var I :  1..MAXTXTBUFNWORDS;
	    S_FSTADR :	CHAR12;
	    S_TXTBFW :	CHAR12;

	begin
	WORD_CNT := WORD_CNT + TXTBUFNWORDS;				(*LCW*)
	if TXTBUFNWORDS > 0 then
	    begin
	    CVOS_12(S_FSTADR,TXTBUFFSTADR);
	    WRITE(PRR,'TXT ',1:8,' ',S_FSTADR,' ',TXTBUFNWORDS:2);
	    for I := 1 to TXTBUFNWORDS do
		begin
		CVOS_S1WORD_12(S_TXTBFW,TXTBUF[I]);
		WRITE(PRR,' ',S_TXTBFW);
		end;
	    WRITELN(PRR);
	    TXTBUFNWORDS := 0
	    end
	end (*CLEAROUT_TXTBUF*);


    procedure OPEN_TXT;
	(*Prepares to output the TXT part of the module.*)

	begin
	TXTBUFNWORDS := 0
	end (*OPEN_TXT*);


    procedure CLOSE_TXT;
	(*Closes off all pending TXT part output.*)

	begin
	CLEAROUT_TXTBUF
	end (*CLOSE_TXT*);


    procedure OUT_TXT(var ADR :  S1RELADR;  WORD :  S1WORD);
	(*Outputs the word WORD as part of a TXT record, to be loaded
	 at address ADR.  Increments ADR by WORDUNITS to prepare for
	 next word.*)

	begin
	if (TXTBUFNWORDS >= MAXTXTBUFNWORDS) or (ADR <> TXTBUFNXTADR)
	then
	    CLEAROUT_TXTBUF;
	if TXTBUFNWORDS = 0 then
	    begin
	    TXTBUFFSTADR := ADR;
	    TXTBUFNXTADR := ADR
	    end;
	TXTBUFNWORDS := TXTBUFNWORDS + 1;
	TXTBUF[TXTBUFNWORDS] := WORD;
	ADR := ADR + WORDUNITS;
	TXTBUFNXTADR := ADR
	end (*OUT_TXT*);

(** OBJECT_MODULE_SEGMENT_CLASS:	OPN_SEG CLS_SEG OUT_SEG OPEN_ESD CLS_ESD OUT_ESD OPEN_ESR CLS_ESR OUT_ESR OPEN_RLD CLOSE_RLD OUT_RLD **)
(**)

    procedure OPN_SEG;
	(*Prepares to output the SEG part of the module.*)

	begin
	(*No-op for now with the intermediate loader format*)
	end (*OPN_SEG*);


    procedure CLS_SEG;
	(*Closes off all pending SEG part output.*)

	begin
	(*No-op for now with the intermediate loader format*)
	end (*CLS_SEG*);


    procedure OUT_SEG(LSNAM :  ALFA;	STYP :	ZSEGTYPE;
		      SEGINX :  ESDINDEX;  SADR :  S1RELADR;
		      SLEN :  integer;  SACMOD :  CHAR17);
	(*Outputs a SEG entry for symbol SNAM of type STYP, segment
	 index SEGINX, address SADR, and length SLEN.*)

	var S_SADR, S_SLEN :  CHAR12;
	    SNAM :  ZSYMBOL;
	    I :  ALFALEN;

	begin
	for I := 1 to 8 do		(*als/peg 25jul79*)
	    SNAM[I] := LSNAM[I];	(*als/peg 25jul79*)
	CVOS_12(S_SADR,  SADR);
	CVOS_12(S_SLEN,  SLEN);
	WRITELN(PRR,'SEG ',SNAM:8,' ',ZSEGTYPE_TO_CHARS[STYP]:4,
		' ',SEGINX:8,' ',S_SADR,' ',S_SLEN,' ',SACMOD);
	end (*OUT_SEG*);


    procedure OPEN_ESD;
	(*Prepares to output the ESD part of the module.*)

	begin
	(*No-op for now with the intermediate loader format*)
	end (*OPEN_ESD*);


    procedure CLS_ESD;
	(*Closes off all pending ESD part output.*)

	begin
	(*No-op for now with the intermediate loader format*)
	end (*CLS_ESD*);


    procedure OUT_ESD(LSNAM :  ALFA;  STYP :  ZESDTYPE;
		      SEGINX :  ESDINDEX;  SADR :  S1RELADR;
		      INX :  ESDINDEX);
	(*Outputs an ESD entry for symbol SNAM of type STYP, segment
	 index SEGINX, address SADR, and index INX.*)

	var S_SADR :  CHAR12;
	    SNAM :  ZSYMBOL;
	    I :  ALFALEN;

	begin
	for I := 1 to 8 do		(*als/peg 25jul79*)
	    SNAM[I] := LSNAM[I];	(*als/peg 25jul79*)
	CVOS_12(S_SADR,  SADR);
	WRITELN(PRR,'ESD ',SNAM:8,' ',ZESDTYPE_TO_CHARS[STYP]:4,
		' ',SEGINX:8,' ',S_SADR,' ',INX:8);
	end (*OUT_ESD*);


    procedure OPEN_ESR;
	(*Prepares to output the ESR part of the module.*)

	begin
	(*No-op for now with the intermediate loader format*)
	end (*OPEN_ESR*);


    procedure CLS_ESR;
	(*Closes off all pending ESR part output.*)

	begin
	(*No-op for now with the intermediate loader format*)
	end (*CLS_ESR*);


    procedure OUT_ESR(LSNAM :  ALFA;  STYP :  ZESRTYPE;
		      INX :  ESRINDEX);
	(*Outputs an ESR entry for symbol SNAM of type STYP and index
	 INX.*)

	var SNAM :  ZSYMBOL;
	    I :  ALFALEN;

	begin
	for I := 1 to 8 do              (*als/peg 25jul79*)
	    SNAM[I] := LSNAM[I];        (*als/peg 25jul79*)
	WRITELN(PRR,
		'ESR ',SNAM:8,' ',ZESRTYPE_TO_CHARS[STYP]:4,' ',INX:8)
	end (*OUT_ESR*);


    procedure OPEN_RLD;
	(*Prepares to output the RLD part of the module.*)

	begin
	(*No-op for now with the intermediate loader format*)
	end (*OPEN_RLD*);


    procedure CLOSE_RLD;
	(*Closes off all pending RLD part output.*)

	begin
	(*No-op for now with the intermediate loader format*)
	end (*CLOSE_RLD*);


    procedure OUT_RLD(LSNAM : ALFA;  IXFLAG :  ZESDESRSEG;
		      SOPR :  ZOPR;  SEGINX :  ESDINDEX;
		      SADR :  S1RELADR;  INX :  ZINDEX);
	(*Outputs an RLD entry for symbol SNAM of type IXFLAG, operation
	 SOPR, segment index SEGINX, address SADR, and index INX.*)

	var S_SADR :  CHAR12;
	    SNAM :  ZSYMBOL;
	    I :  ALFALEN;

	begin
	for I := 1 to 8 do              (*als/peg 25jul79*)
	    SNAM[I] := LSNAM[I];        (*als/peg 25jul79*)
	CVOS_12(S_SADR,  SADR);
	WRITELN(PRR,'RLD ',SNAM:8,' ',ZIXFLAG_TO_CHAR[IXFLAG]:1,
		    ' ',ZOPR_TO_CHARS[SOPR]:2,' ',SEGINX:8,
		    ' ',S_SADR,' ',INX:8)
	end (*OUT_RLD*);



    begin (*GEN_SEGMENT*)

    ALL_CODE_EMITTED := true;					(*DATASTRCH*)

    O2PTR := EVALSAVE.FIXLIST.FIRST;				(*DATASTRCH*)
    while O2PTR <> nil do					(*DATASTRCH*)
	begin
	FIXOPND2(O2PTR↑.OPND2IPTR,EVALSAVE.SIZE);		(*DATASTRCH*)
	O2PTR := O2PTR↑.NEXTPTR					(*DATASTRCH*)
	end;

    O2PTR := EVALSAVE.NEGFIXLIST.FIRST;				(*DATASTRCH*)
    VAL := - EVALSAVE.SIZE;
    while O2PTR <> nil do					(*DATASTRCH*)
	begin
	FIXOPND2(O2PTR↑.OPND2IPTR,VAL);				(*DATASTRCH*)
	O2PTR := O2PTR↑.NEXTPTR					(*DATASTRCH*)
	end;

    O2PTR := STACKFRAME.FIXLIST.FIRST;				(*DATASTRCH8/6*)
    while O2PTR <> nil do					(*DATASTRCH8/6*)
	begin
     	FIXOPND2(O2PTR↑.OPND2IPTR,STACKFRAME.SIZE);		(*DATASTRCH8/6*)
	O2PTR := O2PTR↑.NEXTPTR					(*DATASTRCH8/6*)
	end;

    O2PTR := NEG_SHIFT_FIXLIST.FIRST;				(*DATASTRCH*)
    while O2PTR <> nil do				   	(*DATASTRCH*)
   	begin  							(*DATASTRCH*)
	OPLOC := O2PTR↑.OPND2IPTR↑.INSTOPND2.XWD;
	if not (OPLOC<>nil) then ASSERTFAIL('GEN_SEGME001');
	DSP := OPLOC↑.DISP;
	DSP := (-DSP) * DALIGNMUL;
	OPLOC↑.DISP := DSP; 
	O2PTR := O2PTR↑.NEXTPTR					(*DATASTRCH*)
	end;

    (*Check for undefined labels*)
    for I := 0 to LBLHTSIZEM1 do
	begin
	LPTR := LBLHASHTAB[I];
	while LPTR <> nil do
	    begin
	    if not LPTR↑.DEFINED then
		begin
		ERRINT1 := LPTR↑.LBLNUM;
		ERROR(WL_LPTR_LBLNUM_UNDEFINED)
		end;
	    LPTR := LPTR↑.NEXTPTR
	    end;
	end (*for I := 0 to LBLHTSIZEM1*);

    if TOP <> BOT-1 then
	ERROR (WSTACK_LEFT_NONEMPTY_IN_LAST_SEGMENT);
    if MSTTOP <> 0 then
	ERROR (WMST_WITHOUT_CUP_IN_LAST_SEGMENT);


    CODE_CONCRETIZER;
(** OBJECT_MODULE_SEGMENT_CLASS		**)
(**)

    ASMPC := CURPC;  (*save for reporting literals if ASM on*) (*28AUG79 PTZ*)

    (*Resolve string, real, set literals...*)

    OXPTR := STRINGFIXLIST.FIRST;				(*DATASTRCH*)
    while OXPTR <> nil do					(*DATASTRCH*)
	begin
	FIXDISP(OXPTR↑.XWORDPTR,CURPC);				(*DATASTRCH*)
	OXPTR := OXPTR↑.NEXTPTR					(*DATASTRCH*)
	end;
    CURPC := CURPC  +  STRINGAREA.NWORDS * WORDUNITS;

    OXPTR := REALFIXLIST.FIRST;					(*DATASTRCH*)
    while OXPTR <> nil do					(*DATASTRCH*)
	begin
	FIXDISP(OXPTR↑.XWORDPTR,CURPC);				(*DATASTRCH*)
	OXPTR := OXPTR↑.NEXTPTR					(*DATASTRCH*)
	end;
    CURPC := CURPC  +  REALTBL.NWORDS * WORDUNITS;

    OXPTR := SETFIXLIST.FIRST;					(*DATASTRCH*)
    while OXPTR <> nil do					(*DATASTRCH*)
	begin
	FIXDISP(OXPTR↑.XWORDPTR,CURPC);				(*DATASTRCH*)
	OXPTR := OXPTR↑.NEXTPTR					(*DATASTRCH*)
	end;
    CURPC := CURPC  +  SETTBL.NWORDS * WORDUNITS;

    OXPTR := BOUNDFIXLIST.FIRST;				(*DATASTRCH8/6*)
    while OXPTR <> nil do                                   (*DATASTRCH*)
	begin
	FIXDISP(OXPTR↑.XWORDPTR,CURPC);                     (*DATASTRCH*)
	OXPTR := OXPTR↑.NEXTPTR                             (*DATASTRCH*)
	end;
    CURPC := CURPC  +  BOUNDTBL.NWORDS * WORDUNITS;


    PITPC := CURPC;
    if DEBUG then
	begin
	IPTR := MAINCODE.FIRST;
	S1PC := SEG_EP_RELPC;
	while IPTR <> nil do
	    begin
	    CURS1OPC := IPTR↑.OPCODE;			(*DATASTRCH*)
	    case OPFORMAT[CURS1OPC] of

		VFAKEOP:
		    if CURS1OPC = XPLOC then
			begin (*might emit PLOCs also*)
			INTEGER_TO_S1WORD(W,S1PC);
			EMIT_S1WORD(LOCTBL,W)
			end
		    (*else ignore it*);

		VTOP, VXOP, VSOP:
		    begin
		    S1PC := S1PC + WORDUNITS;
		    if IPTR↑.INSTOPND1.XWD <> nil then		(*DATASTRCH*)
			S1PC := S1PC + WORDUNITS;
		    if IPTR↑.INSTOPND2.XWD <> nil then		(*DATASTRCH*)
			S1PC := S1PC + WORDUNITS
		    end (*VTOP, VXOP, VSOP*);

		VJOP:
		    begin
		    S1PC := S1PC + WORDUNITS;
		    if IPTR↑.INSTOPND1.XWD <> nil then		(*DATASTRCH*)
			S1PC := S1PC + WORDUNITS;
		    if (IPTR↑.PR = 0)and(IPTR↑.INSTOPND2.XWD <> nil) then (*DATASTRCH*)
			S1PC := S1PC + WORDUNITS
		    end (*VJOP*)
	    end (*case*);

	    IPTR := IPTR↑.NEXTPTR;				(*DATASTRCH*)
	    end (*while IPTR <> nil*);

	CURPC := CURPC + LOCTBL.NWORDS * WORDUNITS

	end (*if DEBUG*);


    if ASM then
	begin
	WRITELN(OUTPUT,'**************************  ;START OF  ',
		       CURPROCXN.NAM,'  ',CURPROC);
	WRITELN(OUTPUT,'**************************  ;WRITER-ID: ',
		       SOPA_ID);				(*23JUL79 PTZ*)
	IPTR := MAINCODE.FIRST;
	S1PC := SEG_EP_RELPC;
	while IPTR <> nil do
	    begin
  	    DISASSEMBLE(S1PC,IPTR);  
	    IPTR := IPTR↑.NEXTPTR;				(*DATASTRCH*)
	    end (*while IPTR <> nil*);

(*To report all strings in .PS1*)				(*22DEC78 ALS*)
	PTR := STRINGAREA.FIRST;
	NXTPC := ASMPC;
	if PTR <> nil then WRITELN(OUTPUT);
	while PTR <> nil do
	    begin
	    DISASM(NXTPC,PTR);
	    WRITE(OUTPUT,'ASCII           /');
	    CVCHR_S1WORD_4(SSTR,ICW);
	    WRITE(OUTPUT,SSTR,'/');
	    WRITELN(OUTPUT); 
	    NXTPC := NXTPC+WORDUNITS;
	    PTR := PTR↑.NEXTPTR
	    end (*while PTR <> nil  for  STRINGAREA*);
	PTR := REALTBL.FIRST;
	if PTR <> nil then WRITELN(OUTPUT);
	while PTR <> nil do
	    begin
	    DISASM(NXTPC,PTR);
	    WRITE(OUTPUT,'                ;REAL LITERAL ');
	    DISASM2(PTR);
	    NXTPC := NXTPC+WORDUNITS;
	    PTR := PTR↑.NEXTPTR
	    end  (*while PTR <> nil  for REALTBL*);
	PTR := SETTBL.FIRST;
	if PTR <> nil then WRITELN(OUTPUT);
	while PTR <> nil do
	    begin
	    DISASM(NXTPC,PTR);
	    WRITE(OUTPUT,'                ;SET LITERAL ');
	    DISASM2(PTR);
	    NXTPC := NXTPC+WORDUNITS;
	    PTR := PTR↑.NEXTPTR
	    end  (*while PTR <> nil  for SETTBL*);
	PTR := BOUNDTBL.FIRST;
	if PTR <> nil then WRITELN(OUTPUT);
	while PTR <> nil do
	    begin
	    DISASM(NXTPC,PTR);
	    WRITE(OUTPUT,'                ;BOUND LITERAL ');
	    DISASM2(PTR);
	    NXTPC := NXTPC+WORDUNITS;
	    PTR := PTR↑.NEXTPTR
	    end  (*while PTR <> nil  for BOUNDTBL*);
	PTR := LOCTBL.FIRST;
	if PTR <> nil then WRITELN(OUTPUT);
	while PTR <> nil do
	    begin
	    DISASM(NXTPC,PTR);
	    ICW := PTR↑.CODEWORD;
	    WRITE(OUTPUT,'                ;LOC LITERAL ');
  	    DISASM2(PTR);
	    NXTPC := NXTPC+WORDUNITS;
	    PTR := PTR↑.NEXTPTR
	    end  (*while PTR <> nil  for LOCTBL*);
	WRITELN(OUTPUT);
	WRITE(OUTPUT,chr(12))	(*12 dec = 14 oct = FF (form feed) *)
	end (*if ASM then*)
    else							(*12AUG79 EJG*)
	WRITELN(OUTPUT,'**************************  ;COMPILED :  ',
		       CURPROCXN.NAM,'  ',CURPROC);

    IPTR := MAINCODE.FIRST;						(*LCW*)
    while IPTR <> nil do						(*LCW*)
	begin								(*LCW*)
	S1OP_CNT[IPTR↑.OPCODE] := S1OP_CNT[IPTR↑.OPCODE] + 1;(*LCW*)(*DATASTRCH*)
	IPTR := IPTR↑.NEXTPTR;                        (*DATASTRCH*)	(*LCW*)
	end;								(*LCW*)


    (*** Output the segment to the loader file... ***)


    MAXPC := CURPC;
    NREF := 0; PPTR := PROCTBL.FIRST;
    while PPTR <> nil do
	begin
	NREF := NREF + PPTR↑.FIXLIST.NWORDS;
	PPTR := PPTR↑.NEXTPTR
	end;

    OPEN_SEGMENT(1,MAXPC div WORDUNITS,PROCTBL.NPROCS,2*NREF);


    (*Output the SEG entries...*)

    OPN_SEG;

    OUT_SEG(CURPROCXN.NAM,ZIS,1,SEG_START_RELPC,MAXPC-SEG_START_RELPC,
	    'IN RA            ');

    CLS_SEG;


    (*Output the ESD entries...*)

    OPEN_ESD;

    OUT_ESD(CURPROCXN.NAM,ZIN,1,SEG_START_RELPC,1);

    CLS_ESD;
(** OBJECT_MODULE_SEGMENT_CLASS		**)
(**)

    (*Output the TXT entries...*)

    OPEN_TXT;

    CURPC := SEG_START_RELPC;
    ZSYMBOL_TO_S1WORDS(W1,W2,CURPROCXN.NAM);
    OUT_TXT(CURPC,W1);
    OUT_TXT(CURPC,W2);
    W := ZEROS1WORD;
    if DEBUG then PUTFIELD(W,0,1,1);
    PUTFIELD(W,1,5,LVL_TO_S1REG[CURLVL]);
    OUT_TXT(CURPC,W);
    INTEGER_TO_S1WORD(W,PITPC);
    OUT_TXT(CURPC,W);

    IPTR := MAINCODE.FIRST;
    if not (CURPC = SEG_EP_RELPC) then ASSERTFAIL('GEN_SEGME002');
    while IPTR <> nil do
	begin
	NXTIPTR := IPTR↑.NEXTPTR;				(*DATASTRCH*)
	NXTPC := CURPC + IPTR↑.IWDS * WORDUNITS;		(*DATASTRCH*)
 	CURS1OPC := IPTR↑.OPCODE;				(*DATASTRCH*)
	(* abort if an illegal opcode has been generated *)	(*NOV78 PTZ...*)
	if not (CURS1OPC <> XILLEGAL) then
	    ASSERTFAIL('GEN_SEGME003');				(*...NOV78 PTZ*)
	if not (OPFORMAT[CURS1OPC] = IPTR↑.OPFMT) then		(*DATASTRCH*)
	    ASSERTFAIL('GEN_SEGME012');				(*DATASTRCH*)
	case OPFORMAT[CURS1OPC] of

	    VFAKEOP:
		(*Ignore it*);

	    VTOP, VXOP, VSOP:
		begin
		if OPFORMAT[CURS1OPC] = VTOP then
		    FORMTOP(IPTR) 				(*DATASTRCH*)
		else if OPFORMAT[CURS1OPC] = VXOP then 
		    FORMXOP(IPTR) 				(*DATASTRCH*)
		else if OPFORMAT[CURS1OPC] = VSOP then 
		    FORMSOP(IPTR);				(*DATASTRCH*)
		OUT_TXT(CURPC,S1INSTBUF[S1INST]);		(*DATASTRCH*)
		if IPTR↑.INSTOPND2.XWD <> nil then		(*DATASTRCH*)
		    OUT_TXT(CURPC,S1INSTBUF[S1OPND2XWD]); (*extended OPND2*)
		if IPTR↑.INSTOPND1.XWD <> nil then		(*DATASTRCH*)
		    OUT_TXT(CURPC,S1INSTBUF[S1OPND1XWD]); (*extended OPND1*)
		end (*VTOP, VXOP, VSOP*);

	    VJOP:
		begin
		FORMJOP(IPTR);					(*DATASTRCH*)
		OUT_TXT(CURPC,S1INSTBUF[S1INST]);		(*DATASTRCH*)
		if (IPTR↑.PR = 0)
		  and (IPTR↑.INSTOPND2.XWD <> nil) then		(*DATASTRCH*)
		    OUT_TXT(CURPC,S1INSTBUF[S1OPND2XWD]); (*extended OPND2*)
		if IPTR↑.INSTOPND1.XWD <> nil then		(*DATASTRCH*)
		    OUT_TXT(CURPC,S1INSTBUF[S1OPND1XWD]); (*extended OPND1*)
		end (*VJOP*)
	end (*case*);

	if not (CURPC = NXTPC) then
	     ASSERTFAIL('GEN_SEGME007');    (*DATASTRCH*)
	IPTR := NXTIPTR;
	end (*while IPTR <> nil do*);

    PTR := STRINGAREA.FIRST;
    while PTR <> nil do
	begin
	OUT_TXT(CURPC,PTR↑.CODEWORD);
	PTR := PTR↑.NEXTPTR
	end;

    PTR := REALTBL.FIRST;
    while PTR <> nil do
	begin
	OUT_TXT(CURPC,PTR↑.CODEWORD);
	PTR := PTR↑.NEXTPTR
	end;

    PTR := SETTBL.FIRST;
    while PTR <> nil do
	begin
	OUT_TXT(CURPC,PTR↑.CODEWORD);
	PTR := PTR↑.NEXTPTR
	end;

    PTR := BOUNDTBL.FIRST;
    while PTR <> nil do
	begin
	OUT_TXT(CURPC,PTR↑.CODEWORD);
	PTR := PTR↑.NEXTPTR
	end;

    if not (CURPC = PITPC) then 
	ASSERTFAIL('GEN_SEGME008');	(*DATASTRCH*)
    PTR := LOCTBL.FIRST;
    while PTR <> nil do
	begin
	OUT_TXT(CURPC,PTR↑.CODEWORD);
	PTR := PTR↑.NEXTPTR
	end;

    if not (CURPC = MAXPC) then 
	ASSERTFAIL('GEN_SEGME009');	(*DATASTRCH*)

    CLOSE_TXT;


    (*Output the ESR entries...*)

    OPEN_ESR;

    INX := 1;
    PPTR := PROCTBL.FIRST;
    while PPTR <> nil do
	begin
	OUT_ESR(PPTR↑.NAME,ZIR,INX);
	INX := INX + 1;
	PPTR := PPTR↑.NEXTPTR
	end;
      
    CLS_ESR;


    (*Output the RLD entries...*)

    OPEN_RLD;

    INX := 1;
    PPTR := PROCTBL.FIRST;
    while PPTR <> nil do
	begin
        OXPTR := PPTR↑.FIXLIST.FIRST;				(*DATASTRCH*)
	while OXPTR <> nil do
	    begin
	    TADR := -OXPTR↑.XWORDPTR↑.ADDR			(*DATASTRCH*)
		   + SEG_EP_RELPC + WORDUNITS;
	    if TADR < 0 then			(*this is 30-bit arithmetic*)
		TADR := TADR + (MAXS1ADDR + 1);			(*DATASTRCH*)
		(*A procedure reference operand starts out with a
		 displacement of SEG_EP_RELPC.	During concretization,
		 it has the PC value subtracted from it.  Thus
		 -OXPTR↑.XWORDPTR↑.ADDR+SEG_EP_RELPC is the PC value of
		 the JSR instruction (distance from the beginning of
		 the module), and so adding WORDUNITS yields the PC
		 value of the operand itself.*)		(*DATASTRCH*)
	    OUT_RLD(   PPTR↑.NAME,ZESR, ZPLUS,1,TADR,INX);
					 (*add callee seg addr*)
	    OUT_RLD(CURPROCXN.NAM,ZESD,ZMINUS,1,TADR,  1);
					 (*subtract caller seg addr*)
	    OXPTR := OXPTR↑.NEXTPTR				(*DATASTRCH*)
	    end;
	INX := INX + 1;
	PPTR := PPTR↑.NEXTPTR
	end;

    CLOSE_RLD;


    CLOSE_SEGMENT;

    OLDINSTREC := nil;	 (*So debugging class will survive.*)
    NEWINSTREC := nil;
    TOP := BOT-1;
    MSTTOP := 0;

    new(NEWNP);				 (*compute storage used - 31AUG79 PTZ...*)
    INSTPI.PTR := NEWNP;
    HEAPTOP := INSTPI.INT;
    INSTPI.PTR := OLDNP;
    HEAPBOTTOM := INSTPI.INT;
    TOTAL_STORAGE := TOTAL_STORAGE + (HEAPBOTTOM - HEAPTOP); (*heap grows down*)
    NUM_PROCS_COMPILED := NUM_PROCS_COMPILED + 1;
    MAX_STORAGE := MAX(MAX_STORAGE,HEAPBOTTOM-HEAPTOP);		(*...31AUG79 PTZ*)

(*%IFT D10*)
    DISPOSE(OLDNP); 
(*%ELSE*)
%    RELEASE(OLDNP);	\
(*%ENDC*)
    end (*GEN_SEGMENT*);
(** CALLSTANDARD_CLASS:		SAVE_PARMREGS RESTORE_PARMREGS CALLSTANDARD GENCALL ONE_ARG TWO_SINGLE_ARGS CHECKFILADR ALLOC_EXCESS EXCESS_ARG DEALLOC_EXCESS CHECK_REF_PARM RESULT_PARM **)
(**)

procedure SAVE_PARMREGS;
    (*Archive all the parmregs to the parmreg save area
	in order to make all variables uniformly addressable,
	or in order to free the registers.*)
    (* Shortened to use MOVMS_N  5 DEC 78  ALS *)

    var	LASTPREG :  -1..MAXPAREGM1;
	OPND1, OPND2 :	OPERAND;

    begin
    with CURPROCSPEC do
	begin
	LASTPREG := REGPARMAREA div WORDUNITS - 1;
	if LASTPREG >= 0 then
	    begin
	    REGDISP_OPERAND (OPND1, DISPLAY, R_OFFSET);
	    REG_OPERAND (OPND2, PRM_TO_S1REG [0]);
	    EMITXOP (MOVMS_N[LASTPREG+1], OPND1, OPND2);
	    end;
	end;
    PREGS_ARCHIVED := true;
    end (*SAVE_PARMREGS*);

procedure RESTORE_PARMREGS;
    (*Restore the parmregs from the save area.*)
    (* Shortened to use MOVMS_N  5 Dec 78 ALS *)

    var	LASTPREG :  -1..MAXPAREGM1;
	OPND1, OPND2 :	OPERAND;

    begin
    with CURPROCSPEC do
	begin
	LASTPREG := REGPARMAREA div WORDUNITS - 1;
	if LASTPREG >= 0 then
	    begin
	    REG_OPERAND (OPND1, PRM_TO_S1REG [0]);
	    REGDISP_OPERAND (OPND2, DISPLAY, R_OFFSET);
	    EMITXOP (MOVMS_N[LASTPREG+1], OPND1, OPND2);
	    end;
	end;
    PREGS_ARCHIVED := false;
    end (*RESTORE_PARMREGS*);

procedure ALLOC_EXCESS (EXCWRDS :  integer);	(*moved peg 23sep79...*)
    (*Allocate stack space for EXCWRDS excess parameter words.*)

    var OPND2 :  OPERAND;
    begin
    IMM_OPERAND (OPND2, EXCWRDS*WORDUNITS);
    EMITXOP (XADJSP_UP, OPNDRSP, OPND2)
    end (*ALLOC_EXCESS*);


procedure DEALLOC_EXCESS (EXCWRDS :  integer);
    (*Deallocate EXCWRDS of stack space.*)

    var OPND2 :  OPERAND;
    begin
    IMM_OPERAND (OPND2, EXCWRDS*WORDUNITS);
    EMITTOP(XSUB_S, 0, OPNDRSP, OPND2);
    end (*DEALLOC_EXCESS*);			(*...moved peg 23sep79*)


procedure CALLSTANDARD;
    (*Figure out which standard procedure is being called, load its
	arguments into the proper places, and generate the call.*)

    var OPNDR, OPND1, OPND2, OPNDI1, OPNDI2 :  OPERAND;
	CSP :  P_STANDARDPROC;
	RESCODESTART :	AN_INSTREC;				(*DATASTRCH*)
	RESTYPE :  OPNDTYPE;
	SKIPLOC :  AN_INSTREC;					(*DATASTRCH*)
	JUMPLOC :  AN_INSTREC;					(*ROUND*)
	SKIP1LOC, SKIP2LOC :  AN_INSTREC;		       	(*DATASTRCH*)
	FAKE_REF :  boolean;
	FAKE_PARMREG :	S1REGISTER;
	FAKE_PARMDISP :  integer;


    procedure GENCALL (BOTTOMPARM :  STKINX);
	(*Load the stack (except for parms)
	    to prevent side effects, and generate the JSR instruction,
	    with fixup information.*)

	var CSPNAM :  NAMEREC;
	    OPNDR, OPND2 :  OPERAND;
	begin
	REG_OPERAND (OPNDR, LVL_TO_S1REG[2]);
	EXT_REGADDR_OPERAND (OPND2, S1RPC, SEG_EP_RELPC);	(*EJG*)
	OPND2.FIXUP := XTRNSYMFIX;
	CSPNAM.NAM := '$PCSP           ';  (*can be optimized to 'OWN' var*)
	CSPNAM.LEN := 8;
	CSPNAM.NAM[6] := NAM1.NAM[1];
	CSPNAM.NAM[7] := NAM1.NAM[2];
	CSPNAM.NAM[8] := NAM1.NAM[3];
	UPD_PROCTBL (OPND2.FIXPTR, CSPNAM.NAM);
	LOADSTACKEXCEPT (BOTTOMPARM, TOP);
	EMITJOP (XJSR, 0, OPNDR, OPND2, nil);
	end (*GENCALL*);


    procedure ONE_ARG (ARG :  STKINX;  TYP :  OPNDTYPE);
	(*Load RTB with the argument, coercing to type TYP as needed.*)

	begin
	if not RISFREE[S1RTB] and (RTBUSER <> ARG) then
	    MOVE_AND_FREE_RTB;
	COERCE_AND_MOVE_QUANTITY (OPNDRTB, ARG, TYP);
	FREEDATUMREGS (ARG);
	end (*ONE_ARG*);


    procedure TWO_SINGLE_ARGS (ARG1, ARG2 :  STKINX;
			       TYP1, TYP2 :  OPNDTYPE);
	(*Load RTB with two singleword arguments, coercing as needed.*)

	var OPNDR :  OPERAND;
	begin
	if not (not IS_DOUBLE[TYP1] and not IS_DOUBLE[TYP2]) then
            ASSERTFAIL('TWO_SINGL001');
	COERCE_DATUM (ARG1, TYP1);
	if not RISFREE[S1RTB] and not((RTBUSER=ARG1) or (RTBUSER=ARG2))
	    then MOVE_AND_FREE_RTB;
	REG_OPERAND (OPNDR, succ(S1RTB) );
	COERCE_AND_MOVE_QUANTITY (OPNDR, ARG2, TYP2);
	MOVE_QUANTITY (OPNDRTB, ARG1);
	FREEDATUMREGS (ARG1);
	FREEDATUMREGS (ARG2);
	end (*TWO_SINGLE_ARGS*);


    procedure CHECKFILADR (STE :  STKINX);
	(*Verify that STK[STE] is an address in (1,LCIOFILADR).*)

	begin
	if STK[STE].DTYPE <> TYPUA then
	    ERROR (WFILE_ADDRESS_NEEDED)
	else if not DAT_IS_FILADR(STE) then
	    ERROR (WSIO_DIDNT_SEE_FILEADDR);
	end (*CHECKFILADR*);


    procedure EXCESS_ARG (NUM, TOT :  integer;
			ARG :  STKINX;	TYP :  OPNDTYPE);
	(*Store the argument into the NUMth excess parm location
	    in a block of TOT, coercing to type TYP if needed.*)

	var OPND1 :  OPERAND;
	begin
	REGDISP_OPERAND (OPND1, S1RSP, -(TOT-NUM+1) * WORDUNITS);
	COERCE_AND_MOVE_QUANTITY (OPND1, ARG, TYP);
	FREEDATUMREGS (ARG);
	end (*EXCESS_ARGS*);


    procedure CHECK_REF_PARM (STE :  STKINX);
	(*The datum is the address of a reference parameter
	    (e.g. for a READ).	If the reference parameter
	    is a local parm in a register, TRANSLATE_LVLDSP
	    has already changed the address to that of the
	    corresponding save location.  We must finish
	    the job here by emitting moves in one or two
	    directions to fake the reference parameter
	    by a value result parameter.  This procedure
	    merely notes whether such a simulation may be
	    necessary.*)

	var FIRSTPARM :  integer;

	begin
	with STK[STE], CURPROCSPEC do
	    begin
	    if not ( DTYPE = TYPUA) then ASSERTFAIL('CHECK_REF001');
	    FIRSTPARM := R_OFFSET;
	    if (NVPAS = 0) and (FPA.WHICH = MEM)
	       and (FPA.MEMADR.LVL = CURLVL)
	       and (FIRSTPARM <= FPA.MEMADR.DSPLMT)
	       and (FPA.MEMADR.DSPLMT < FIRSTPARM+REGPARMAREA) then
		begin
		FAKE_REF := true;
		FAKE_PARMDISP := FPA.MEMADR.DSPLMT;
		FAKE_PARMREG := PRM_TO_S1REG
		      [(FPA.MEMADR.DSPLMT - FIRSTPARM) div WORDUNITS];
		end
	    else
		FAKE_REF := false;
	    end (*with*)
	end (*CHECK_REF_PARM*);


    procedure RESULT_PARM (DTYPE :  OPNDTYPE);
	(*After completing the standard procedure, copy a
	    (possibly modified) local regparm back into the
	    register from the corresponding regparm save
	    location.
	    Note : no VALUE_PARM procedure is needed at
	    present because reference parms are only used
	    by standard procs if they wish to achieve result
	    parms.*)

	var OPND1, OPND2 :  OPERAND;

	begin
	if not ( FAKE_REF) then ASSERTFAIL('RESLT_PRM001');
	REG_OPERAND (OPND1, FAKE_PARMREG);
	REGDISP_OPERAND (OPND2, DISPLAY, FAKE_PARMDISP);
	EMITXOP (MOV_X_X[DTYPE], OPND1, OPND2)
	end (*RESULT_PARM*);





    begin  (*CALLSTANDARD*)
    CSP := NAME_TO_CSP(NAM1);

    case CSP of

	QATN, QEXP, QSIN, QCOS, QLOG, QSQT, QCLK :
	    begin
	    if CSP = QCLK then ONE_ARG (TOP, TYPUJ)
	    else ONE_ARG (TOP, TYPUR);
	    GENCALL (TOP);
	    REG_DATUM (TOP, STK[TOP].CODESTART, STK[TOP].DTYPE,S1RTB);
	    if CSP = QCLK then ALLOCRG (S1RTB) else ALLOCRP (S1RTB);
	    RTBUSER := TOP;
	    RTBDOUB := IS_DOUBLE[STK[TOP].DTYPE];
	    end (*QATN,...,QCLK*);

	QXIT :
	    begin
	    ONE_ARG (TOP, TYPUJ);
	    GENCALL (TOP);
	    POPTOP;
	    end (*QXIT*);

	QTRP :
	    begin
	    SAVE_PARMREGS;
	    TWO_SINGLE_ARGS (TOP-1, TOP, TYPUJ, TYPUA);
	    GENCALL (TOP-1);
	    POPTOP;   POPTOP;
	    RESTORE_PARMREGS;
	    end (*QTRP*);

	QGET, QPUT, QRLN, QWLN :				(*FILECH*)
	    begin
	    CHECKFILADR (TOP);
	    GENCALL (TOP);
	    end (*QGET,...,QWLN*);				(*FILECH*)

(*FILECH...*)
	QRES, QREW :
	    begin
	    CHECKFILADR (TOP-2);
	    TWO_SINGLE_ARGS (TOP-1, TOP, TYPUA, TYPUJ);
	    GENCALL (TOP-2);
	    POPTOP;   POPTOP;
	    end (*QRES, QREW*);
(*...FILECH*)

	QRDB :
	    begin
	    CHECKFILADR (TOP-1);
	    CHECK_REF_PARM (TOP);
	    ONE_ARG (TOP, TYPUA);
	    GENCALL (TOP-1);
	    if FAKE_REF then RESULT_PARM (TYPUB);
	    POPTOP;
	    end (*QRDB*);

	QRDC :
	    begin
	    CHECKFILADR (TOP-1);
	    CHECK_REF_PARM (TOP);
	    ONE_ARG (TOP, TYPUA);
	    GENCALL (TOP-1);
	    if FAKE_REF then RESULT_PARM (TYPUC);
	    POPTOP;
	    end (*QRDC*);

	QRDI :
	    begin
	    CHECKFILADR (TOP-1);
	    CHECK_REF_PARM (TOP);
	    ONE_ARG (TOP, TYPUA);
	    GENCALL (TOP-1);
	    if FAKE_REF then RESULT_PARM (TYPUJ);
	    POPTOP;
	    end (*QRDI*);

	QRDR :
	    begin
	    CHECKFILADR (TOP-1);
	    CHECK_REF_PARM (TOP);
	    ONE_ARG (TOP, TYPUA);
	    GENCALL (TOP-1);
	    if FAKE_REF then RESULT_PARM (TYPUR);
	    POPTOP;
	    end (*QRDR*);

	QRDS :
	    begin
	    CHECKFILADR (TOP-2);
	    TWO_SINGLE_ARGS (TOP-1, TOP, TYPUA, TYPUJ);
	    GENCALL (TOP-2);
	    POPTOP;   POPTOP;
	    end (*QRDS*);

	QWRB :
	    begin
	    CHECKFILADR (TOP-2);
	    TWO_SINGLE_ARGS (TOP-1, TOP, TYPUB, TYPUJ);
	    GENCALL (TOP-2);
	    POPTOP;   POPTOP;
	    end (*QWRB*);

	QWRC :
	    begin
	    CHECKFILADR (TOP-2);
	    TWO_SINGLE_ARGS (TOP-1, TOP, TYPUC, TYPUJ);
	    GENCALL (TOP-2);
	    POPTOP;   POPTOP;
	    end (*QWRC*);

	QWRI :
	    begin
	    CHECKFILADR (TOP-2);
	    TWO_SINGLE_ARGS (TOP-1, TOP, TYPUJ, TYPUJ);
	    GENCALL (TOP-2);
	    POPTOP;   POPTOP;
	    end (*QWRI*);

	QWRR :
	    begin
	    POPTOP;			(*Ignore fraction length for now. LCW*)
	    CHECKFILADR (TOP-2);
	    ALLOC_EXCESS (1);
	    EXCESS_ARG (1, 1, TOP, TYPUJ);
	    ONE_ARG (TOP-1, TYPUR);
	    GENCALL (TOP-2);
	    DEALLOC_EXCESS (1);
	    POPTOP;   POPTOP;
	    end (*QWRR*);

	QWRS :
	    begin
	    CHECKFILADR (TOP-3);
	    ALLOC_EXCESS (1);
	    EXCESS_ARG (1, 1, TOP, TYPUJ);
	    TWO_SINGLE_ARGS (TOP-2, TOP-1, TYPUA, TYPUJ);
	    GENCALL (TOP-3);
	    DEALLOC_EXCESS (1);
	    POPTOP;   POPTOP;	POPTOP;
	    end (*QWRS*);

	QELN, QEOF :
	    begin
	    CHECKFILADR (TOP);
	    if not RISFREE[S1RTB] then MOVE_AND_FREE_RTB;
	    GENCALL (TOP);
	    (*Insert the boolean answer under the FILADR.*)
	    PUSHTOP;
	    if not (RISFREE[S1RTB] or (RTBUSER<>TOP-1)) then
                ASSERTFAIL('QELN,QEOF001');
	    STK[TOP] := STK[TOP-1];
		(*This works since datum does not include RTB.*)
	    REG_DATUM (TOP-1, STK[TOP-1].CODESTART,
					TYPUB, S1RTB);
	    STK[TOP-1].BREPRES := BINTVAL;
	    ALLOCRG (S1RTB);
	    RTBUSER := TOP-1;
	    RTBDOUB := false;
	    end (*QELN, QEOF*);



	QRND :						(*ROUND...*)
	    with STK[TOP] do
		begin
		if not IS_REAL[DTYPE] then ERROR(WROUND_OF_NON_REAL);
		if IS_DOUBLE[DTYPE] then ERROR(WNOT_IMPLEMENTED);
		if IS_CONSTANT(TOP) then
		    begin
		    FPA := ZEROFPA;
		    FPA.MEMADR.DSPLMT := round(RCNST);
		    RCNST := 0.0;
		    DTYPE := TYP;
		    end (*constant*)
		else
		    begin (*not constant*)
		    if not RISFREE[S1RTB] then MOVE_AND_FREE_RTB;
		    ALLOCRG(S1RTB);  RTBUSER := TOP;
		    RESCODESTART := CODESTART;
		    GET_OPERAND(OPND1, TOP);
		    REAL_IMM_OPERAND(OPND2, 0.0);
		    SKIPLOC := NEWINSTREC;
		    EMITSOP(XSKP_LSS_S, 0, OPND1, OPND2, nil);
		    REAL_IMM_OPERAND(OPND2, 0.5);
		    EMITTOP(XFADD_S, 3, OPND1, OPND2);
		    JUMPLOC := NEWINSTREC;
		    EMITJOP (XJMPA, 0, UNUSED_OP, ZERO_OP, nil);
		    FIXSOP(SKIPLOC, NEWINSTREC);
		    REAL_IMM_OPERAND(OPND2, -0.5);
		    EMITTOP(XFADD_S, 3, OPND1, OPND2);
		    FIXJOP(JUMPLOC, NEWINSTREC);
		    EMITXOP(XFX_DM_S_S, OPNDRTB, OPNDRTB);
		    FREEREGSBUTTHESE(TOP, [S1RTB]);
		    REG_DATUM(TOP, RESCODESTART, TYP, S1RTB);
		    end (*not constant*);
		end (*with STK[TOP] do, QRND*);		(*...ROUND*)


	QSIO :
	    begin
	    REGDISP_OPERAND (OPND1,
			LVL_TO_S1REG[1],
			LCIOFILADR + FILE_OFFSET);
	    with STK[TOP] do
		begin
		if DTYPE <> TYPUA then
		    ERROR (WSIO_WITH_NONADDRESS);
		MOVE_QUANTITY (OPND1, TOP);
		FREEDATUMREGS (TOP);
		RESCODESTART := CODESTART;
		STK[TOP] := ZERODATUM;
		CODESTART := RESCODESTART;
		DTYPE := TYPUA;
		NVPAS := 1;
		VPA1.VPA.WHICH := MEM;
		VPA1.VPA.MEMADR.LVL := 1;
		VPA1.VPA.MEMADR.DSPLMT :=
			  LCIOFILADR + FILE_OFFSET;
		end (*with STK[TOP] do*);
	    end (*QSIO*);

	QEIO :
	    begin
	    CHECKFILADR (TOP);
	    POPTOP;
	    end (*QEIO*);

	QNEW :
	    begin
	    if not IS_INTEGER[STK[TOP].DTYPE] or
		      (STK[TOP-1].DTYPE <> TYPUA) then
		ERROR (WNEW_MUST_HAVE_ADDR_AND_INT);
	    COERCE_DATUM (TOP, TYPUJ);
	    GET_OPERAND (OPND2, TOP);
	    (*Check alignment.*)
	    if IS_CONSTANT(TOP) then
		begin
		if STK[TOP].FPA.MEMADR.DSPLMT
		  mod WORDUNITS <> 0 then
		    ERROR (WALIGNMENT_ERROR);
		end
	    else if DEBUG then
		begin  (*Check at run time.*)
		IMM_OPERAND (OPND1, WORDUNITS-1);
		SKIPLOC := NEWINSTREC;
		EMITSOP (XSKP_NON_S, 0, OPND1, OPND2, nil);
		IMM_OPERAND (OPNDI1, 1);
		IMM_OPERAND (OPNDI2, -1);
		(*Check 0<=-1<=1 : fake TRAP SELF*)
		EMITXOP (XBTRP_0_S, OPNDI1, OPNDI2); 	       (*BNDTRPKLU*)
(*		EMITJOP(XHALT,0,UNUSED_OP,ZERO_OP,NEWINSTREC); (*BNDTRPKLU*)
		FIXSOP (SKIPLOC, NEWINSTREC);
		end (*Check at run time.*);
	    REG_OPERAND (OPNDR, pred(S1RNP));  (*SP-NP pair*)
	    EMITXOP (XADJSP_DN, OPNDR, OPND2);
	    GET_ADDRESS (OPND1, TOP-1);
	    REG_OPERAND (OPNDR, S1RNP);
	    EMITXOP (XMOV_S_S, OPND1, OPNDR);
	    FREEDATUMREGS (TOP);   POPTOP;
	    FREEDATUMREGS (TOP);   POPTOP;
	    end (*QNEW*);

	QSAV :
	    begin
	    if STK[TOP].DTYPE <> TYPUA then
		ERROR (WSAV_NEEDS_ADDR);
	    GET_ADDRESS (OPND1, TOP);
	    REG_OPERAND (OPNDR, S1RNP);
	    EMITXOP (XMOV_S_S, OPND1, OPNDR);
	    FREEDATUMREGS (TOP);
	    POPTOP;
	    end (*QSAV*);

	QRST :
	    begin
	    if STK[TOP].DTYPE <> TYPUA then
		ERROR (WRST_NEEDS_ADDR);
	    if DEBUG then
		begin
		ADDR_OPERAND (OPND1, S1RNPMEMADR);	       (*BNDTRPKLU*)
		GET_OPERAND (OPND2, TOP);		       (*BNDTRPKLU*)
		EMITXOP (XBTRP_B_S, OPND1, OPND2);	       (*BNDTRPKLU*)
(*		GET_OPERAND (OPND2, TOP);		       (*BNDTRPKLU*)
(*		ADDR_OPERAND (OPND1, S1RNPMEMADR);	       (*BNDTRPKLU*)
(*		SKIP1LOC := NEWINSTREC;			       (*BNDTRPKLU*)
(*		EMITSOP (XSKP_LSS_S, 0, OPND2, OPND1, nil);    (*BNDTRPKLU*)
(*		ADDR_OPERAND (OPND1, S1RNPMEMADR+WORDUNITS);   (*BNDTRPKLU*)
(*		SKIP2LOC := NEWINSTREC;			       (*BNDTRPKLU*)
(*		EMITSOP (XSKP_LEQ_S, 0, OPND2, OPND1, nil);    (*BNDTRPKLU*)
(*		FIXSOP (SKIP1LOC, NEWINSTREC);		       (*BNDTRPKLU*)
(*		EMITJOP (XHALT, 0, UNUSED_OP, ZERO_OP,	       (*BNDTRPKLU*)
(*						NEWINSTREC);   (*BNDTRPKLU*)
(*		FIXSOP (SKIP2LOC, NEWINSTREC);		       (*BNDTRPKLU*)
		end (*DEBUG*);
	    REG_OPERAND (OPNDR, S1RNP);
	    MOVE_QUANTITY (OPNDR, TOP);
	    FREEDATUMREGS (TOP);
	    POPTOP;
	    end (*QRST*);


	end (*case CSP of*);

    if (CSP in [QGET,QPUT,QRDB,QRDC,QRDI,QRDR,QRDS,
		QRES,QREW,QRLN,QWLN,QWRB,QWRC,QWRI,QWRR,QWRS])
       and (TOP <> BOT) then
	ERROR (WSTACK_NOT_SINGLE)

    else if (CSP in [QTRP,QXIT,QNEW,QSAV,QRST])
	     and (TOP <> BOT-1) then
	ERROR (WSTACK_NON_EMPTY);

    end (*CALLSTANDARD*);

(*** ASSEMBLE_NEXT_INSTRUCTION_CLASS:	ASMNXTINST ***)
(**)


procedure ASMNXTINST;

var
    S1OP, MOVEOP :  S1OPCODE;
    OPND, OPND1, OPND2, OPNDR, OPNDR1, OPNDR2 :  OPERAND;
    RESTYPE :	OPNDTYPE;
    RESCODESTART :  AN_INSTREC;					(*DATASTRCH*)
    RESDBL :  boolean;
    LOWBOUND, HIGHBOUND :  integer;		(* peg 07jul79 *)
    CORRECT, NO_ERROR, BOOL_IN_STK :  boolean;		(* peg *)
    COMBINABLE, CALCULABLE :  boolean;
    TOOMUCH1, TOOMUCH2 :  boolean;
    STE, PARM, UNSIMPLE, SIMPLER, GROUP1, GROUP2 :  STKINX;
    PTR, NEXT :  AN_INSTREC;					(*DATASTRCH*)
    O2PTR : AN_OPND2REC;					(*DATASTRCH*)
    INSTLOC, SKIPLOC, JUMPLOC, FALLTHRUJUMP :  AN_INSTREC;	(*DATASTRCH*)
    SKIP1LOC, SKIP2LOC :  AN_INSTREC;			       (*BNDTRPKLU*)(*DATASTRCH*)
    TMPJUMPLIST :  JUMPLIST;
    DEST, DEST1, DEST2, OP1RG, OP2RG, OPRRG :  S1REGISTER;
    DESTREGS :  SETOFS1REGS;		(*PEG*)
    OP1GBL :  S1GBL;
    LPTR :  A_LBLHASHENT;
    ONE_IF_OR :  BIT;
    MAXFINALIND :  INDIRECTION;
    PR_BIT :  BIT;
    SP_TWIDDLE :  integer;
    SKIPSMALL, SKIPNOTBIG, JUMPDEFAULT, JUMPINDEXED :  AN_INSTREC;(*DATASTRCH*)
    EXCESS :  integer;
    CONSTPART :  integer;
    SHIFTDIST :  integer;
    I :  integer;
    STARTBIT :	S1BITNUM;
    INDEX :  SETPART_INDEX;	(*setch*)
    PREG :  S1REGISTER;		(* peg 01aug79 *)
    LASTREGPARM :  STKINX;	(* peg 09aug79 *)
    LASTPREG, DESTLASTPREG :  -1..MAXPAREGM1;
    PWORD :  NONNEGINT;
    PREGS :  NUMBER_OF_PAREGS;
    DSPL :  integer;
    OFFSET :  integer;				(*peg 03aug79*)
    LABNUM, LABNUM1, LABNUM2 :  LBL_INDEX;
    RTBSAVED :	boolean;
    RTBDATUM :	STKINX;
    RTBDSPL :  integer;
    IPTR :  AN_INSTREC;						(*DATASTRCH*)
    S1PC :  integer;
    XFER_CNT :  integer;
    PRMTOP : STKINX;
(*** ANI_CLASS:	ARITH_1_OPS UABS UNEG UADD UINC UDEC ***)
(**)

procedure ARITH_1_OPS;
begin
case OPC of

UABS, UNEG :				(* als/peg 28jun79 *)

    with STK[TOP] do
	begin
	if TYP <> DTYPE then ERROR(WINSTR_TYPE_NOT_DATUM_TYPE);
	if not IS_SIGNED_NUM[DTYPE] then  ERROR(WABS_OR_NEG_OF_NONSIGNED);
	if IS_CONSTANT(TOP) then
	    begin
	    if IS_INTEGER[DTYPE] then
		if OPC = UABS then
		    FPA.MEMADR.DSPLMT := ABS(FPA.MEMADR.DSPLMT)
		else (*OPC = UNEG*)
		    FPA.MEMADR.DSPLMT := -FPA.MEMADR.DSPLMT
	    else (*IS_REAL*)
		if OPC = UABS then
		    RCNST := ABS(RCNST)
		else (*OPC = UNEG*)
		    RCNST := -RCNST
	    end (*IS_CONSTANT(TOP)*)
	else (*not constant*)
	    begin
	    GET_OPERAND(OPND2,TOP);
	    FREEDATUMREGS(TOP);
	    if IS_DOUBLE[DTYPE] then FINDRP else FINDRG;
	    REG_OPERAND(OPND1,NXTRG);
	    if OPC = UABS then S1OP := ABS_X[DTYPE]
			  else S1OP := NEG_X[DTYPE];
	    EMITXOP(S1OP,OPND1,OPND2);
	    REG_DATUM(TOP,CODESTART,DTYPE,NXTRG)
	    end (*not constant*)
        end (*UABS, UNEG*);


UADD :			(* als/peg 28jun79 *)

    begin
    if STK[TOP].DTYPE <> TYP then ERROR(WINSTR_TYPE_NOT_DATUM_TYPE);
    if STK[TOP].DTYPE <> STK[TOP-1].DTYPE then
	  ERROR(WBINARY_OPND_TYPE_CONFLICT);
    if IS_INTEGER[TYP] then
	begin
	if ((TYP = TYPUJ) or (TYP = TYPUL)) then
	    ADD_TOP_TWO_DATUMS
	else
	    begin  (*TYPUI TYPUK*)
	    if IS_CONSTANT(TOP-1) or IS_CONSTANT(TOP) then
		ERROR(WNOT_IMPLEMENTED);
	    GET_OPERAND (OPND1, TOP-1);
	    GET_OPERAND (OPND2, TOP);
	    ALLOC_AND_EMIT_TOP (DEST, XADD_D, OPND1, OPND2,
				true, true, true, TOP-1);
	    FREEREGSBUTTHESE (TOP, [DEST]);
	    POPTOP;
	    FREEREGSBUTTHESE (TOP, [DEST]);
	    with STK[TOP] do
		REG_DATUM (TOP, CODESTART, TYP, DEST);
	    end (*TYPUI TYPUK*);
	end (*IS_INTEGER*) else

    if IS_REAL[TYP] then
	begin
	RESCODESTART := STK[TOP-1].CODESTART;
	RESTYPE := STK[TOP-1].DTYPE;
	RESDBL := IS_DOUBLE[RESTYPE];
	if IS_CONSTANT(TOP) and IS_CONSTANT(TOP-1) then
	    begin
	    if not (RESTYPE = TYPUR) then ASSERTFAIL('UADD     001');
	    STK[TOP-1].RCNST := STK[TOP-1].RCNST + STK[TOP].RCNST;
	    POPTOP;
	    end
	else (*not both constants*)
	    begin
	    S1OP := REAL_ARITH_OP[S1SIZE[RESTYPE],OPC];
	    GET_OPERAND(OPND1,TOP-1);
	    GET_OPERAND(OPND2,TOP);
	    ALLOC_AND_EMIT_TOP(DEST, S1OP, OPND1, OPND2,
			       RESDBL, RESDBL, RESDBL, TOP-1);
	    FREEREGSBUTTHESE(TOP,[DEST]); 
	    POPTOP; 
	    FREEREGSBUTTHESE(TOP,[DEST]);
	    REG_DATUM(TOP,RESCODESTART,RESTYPE,DEST)
	    end (*not both constants*)
	end (*IS_REAL*)

    else ERROR(WARITH_ON_WRONG_DT);
    end (* UADD *);


UINC, UDEC :			(* als/peg 28jun79 *)

    begin
    if STK[TOP].DTYPE <> TYP then  ERROR(WINSTR_TYPE_NOT_DATUM_TYPE);
    if not ((IS_INTEGER[TYP]) or (TYP in [TYPUA,TYPUB,TYPUC])) then
	ERROR(WINVAL_U_TYPECODE);
    if TYP = TYPUA then
	if I1 mod QWBITS <> 0 then ERROR(WALIGNMENT_ERROR)
	else I1 := I1 div QWBITS;
    if OPC = UDEC then  I1 := -I1;
    INCREMENT_DATUM (TOP, I1);
    end (*UINC,UDEC*);

end (*case OPC of*)
end (*ARITH_1_OPS*);

(*** ANI_CLASS:	ARITH_2_OPS USUB ***)
(**)


procedure ARITH_2_OPS;
begin
case OPC of

USUB :			(* als/peg 28jun79 *)

  begin
  if STK[TOP].DTYPE <> TYP then ERROR(WINSTR_TYPE_NOT_DATUM_TYPE);
  if STK[TOP].DTYPE <> STK[TOP-1].DTYPE then
	ERROR(WBINARY_OPND_TYPE_CONFLICT);
  if IS_INTEGER[TYP] then
      begin
      RESCODESTART := STK[TOP-1].CODESTART;
      RESTYPE := TYP;
      if ((TYP = TYPUI) or (TYP = TYPUK)) then
	  begin
	  if IS_CONSTANT(TOP-1) or IS_CONSTANT(TOP) then
	      ERROR(WNOT_IMPLEMENTED);
	  GET_OPERAND (OPND1, TOP-1);
	  GET_OPERAND (OPND2, TOP);
	  ALLOC_AND_EMIT_TOP (DEST, XSUB_D, OPND1, OPND2,
			      true, true, true, TOP-1);
	  FREEREGSBUTTHESE (TOP, [DEST]);
	  POPTOP;
	  FREEREGSBUTTHESE (TOP, [DEST]);
	  REG_DATUM (TOP, RESCODESTART, RESTYPE, DEST);
	  end (*TYPUI, TYPUK*)
      else
	  begin (*TYPUJ, TYPUL*)
	  COERCE_INT_DATUM(TOP-1);
	  COERCE_INT_DATUM(TOP);
	  COMBINABLE := false;
	  CALCULABLE := false;
	  repeat
	      if (STK[TOP].NVPAS=0) and (STK[TOP].FPA=ZEROFPA) then
		  COMBINABLE := true
	      else if IS_CONSTANT(TOP) and (STK[TOP-1].FINALIND=IND0) then
		  COMBINABLE := true
	      else
		  begin  (*not combinable*)
		  CONSTPART := 0;
		  with STK[TOP-1] do
		      if FINALIND = IND0 then
			  begin
			  CONSTPART := FPA.MEMADR.DSPLMT;
			  FPA.MEMADR.DSPLMT := 0;
			  end;
		  with STK[TOP] do
		      if FINALIND = IND0 then
			  begin
			  CONSTPART := CONSTPART - FPA.MEMADR.DSPLMT;
			  FPA.MEMADR.DSPLMT := 0;
			  end;
		  if (STK[TOP-1].NVPAS=0) and (STK[TOP-1].FPA=ZEROFPA) then
		      begin  (*replace hard zero by const part*)
		      STK[TOP-1].FPA.MEMADR.DSPLMT := CONSTPART;
		      CONSTPART := 0;
		      end
		  else if (STK[TOP].NVPAS=0) and (STK[TOP].FPA=ZEROFPA) then
		      begin  (*replace hard zero by const part*)
		      STK[TOP].FPA.MEMADR.DSPLMT := -CONSTPART;
		      CONSTPART := 0;
		      end;

		  FIT_IN_OPERAND (TOOMUCH1, OPND1, TOP-1);
		  FIT_IN_OPERAND (TOOMUCH2, OPND2, TOP);
		  if not TOOMUCH1 and not TOOMUCH2 then
		      CALCULABLE := true
		  else
		      begin  (*must simplify*)
		      if not TOOMUCH1 then
			  begin
			  UNSIMPLE := TOP;
			  SIMPLER := TOP-1;
			  CONSTPART := -CONSTPART;
			  end
		      else if not TOOMUCH2 then
			  begin
			  UNSIMPLE := TOP-1;
			  SIMPLER := TOP;
			  end
		      else (*select one at random*)
			  begin
			  UNSIMPLE := TOP-1;
			  SIMPLER := TOP;
			  end;
		      if CONSTPART <> 0 then
			  if STK[UNSIMPLE].FINALIND = IND0 then
			      begin
			      if not (STK[UNSIMPLE].FPA.MEMADR.DSPLMT=0) then
				  ASSERTFAIL('USUB     001');
			      STK[UNSIMPLE].FPA.MEMADR.DSPLMT:=CONSTPART
			      end
			  else
			      begin
			      if not((STK[SIMPLER].FINALIND=IND0) and
				     (STK[SIMPLER].FPA.MEMADR.DSPLMT=0)) then
				  ASSERTFAIL('USUB     002');
			      STK[SIMPLER].FPA.MEMADR.DSPLMT:=CONSTPART;
			      end;

		      SIMPLIFY (UNSIMPLE);
		      end (*must simplify*);
		  end (*not combinable*);
	  until COMBINABLE or CALCULABLE;

	  if COMBINABLE then
	      begin
	      STK[TOP-1].FPA.MEMADR.DSPLMT :=
		  STK[TOP-1].FPA.MEMADR.DSPLMT - STK[TOP].FPA.MEMADR.DSPLMT;
	      POPTOP;
	      STK[TOP].CODESTART := RESCODESTART;
	      end (*COMBINABLE*)

	  else
	      begin  (*CALCULABLE*)
	      ADD_SUB_SINGLE (DEST, XSUB_S, OPND1, OPND2, TOP-1);
	      FREEREGSBUTTHESE(TOP,[DEST]);
	      POPTOP;
	      FREEREGSBUTTHESE(TOP,[DEST]);
	      REG_DATUM (TOP, RESCODESTART, RESTYPE, DEST);
	      STK[TOP].FPA.MEMADR.DSPLMT := CONSTPART;
	      end (*CALCULABLE*);

	  end (*TYPUJ, YYPUL*);

      end (*IS_INTEGER*)

  else if IS_REAL[TYP] then
      if IS_CONSTANT(TOP) and IS_CONSTANT(TOP-1) then
	  begin
	  STK[TOP-1].RCNST := STK[TOP-1].RCNST - STK[TOP].RCNST;
	  POPTOP
	  end
      else (*not both constants*)
	  begin
	  RESCODESTART := STK[TOP-1].CODESTART;
	  RESTYPE := STK[TOP-1].DTYPE;
	  RESDBL := IS_DOUBLE[RESTYPE];
	  S1OP := REAL_ARITH_OP[S1SIZE[RESTYPE],OPC];
	  GET_OPERAND(OPND1,TOP-1);
	  GET_OPERAND(OPND2,TOP);
	  ALLOC_AND_EMIT_TOP(DEST, S1OP, OPND1, OPND2,
			     RESDBL, RESDBL, RESDBL, TOP-1);
	  FREEREGSBUTTHESE(TOP,[DEST]); 
	  POPTOP; 
	  FREEREGSBUTTHESE(TOP,[DEST]);
	  REG_DATUM(TOP,RESCODESTART,RESTYPE,DEST)
	  end (*not both constants*)

  else ERROR(WARITH_ON_WRONG_DT);

  end (* USUB *);

end (*case OPC of*)
end (*ARITH_2_OPS*);

(*** ANI_CLASS:	ARITH_3_OPS UMPY USQR ***)
(**)
    

procedure ARITH_3_OPS;
begin
case OPC of (*UMPY, USQR*)

UMPY :			(* als/peg 28jun79 *)
    begin
    if STK[TOP].DTYPE <> TYP then ERROR(WINSTR_TYPE_NOT_DATUM_TYPE);
    if STK[TOP].DTYPE <> STK[TOP-1].DTYPE then
	  ERROR(WBINARY_OPND_TYPE_CONFLICT);
    if IS_INTEGER[TYP] then
	begin
	RESCODESTART := STK[TOP-1].CODESTART;
	RESTYPE := TYP;
	if ((TYP = TYPUI) or (TYP = TYPUK)) then
	    begin
	    if IS_CONSTANT(TOP-1) or IS_CONSTANT(TOP) then
		ERROR(WNOT_IMPLEMENTED);
	    GET_OPERAND (OPND1, TOP-1);
	    GET_OPERAND (OPND2, TOP);
	    ALLOC_AND_EMIT_TOP (DEST, XMULT_D, OPND1, OPND2,
				true, true, true, TOP-1);
	    FREEREGSBUTTHESE (TOP, [DEST]);
	    POPTOP;
	    FREEREGSBUTTHESE (TOP, [DEST]);
	    REG_DATUM (TOP, RESCODESTART, RESTYPE, DEST);
	    end (*TYPUI TYPUK*)
	else
	    begin  (*TYPUJ TYPUL*)
	    COERCE_INT_DATUM(TOP-1);
	    COERCE_INT_DATUM(TOP);
	    COMBINABLE := false;
	    CALCULABLE := false;

	    repeat

		if IS_CONSTANT(TOP) then
		    begin
		    if IS_CONSTANT(TOP-1) then
			COMBINABLE := true
		    else
			begin
			SHIFTDIST := POWER2(STK[TOP].FPA.MEMADR.DSPLMT);
			with STK[TOP-1] do
			    if (SHIFTDIST>=0) and (FPA.MEMADR.LVL=0) and
			       (FINALIND = IND0) and
			       ((NVPAS=0) or ((NVPAS=1) and
				 (VPA1.VSHIFT+SHIFTDIST <= SFLDMAX) )) then
				    COMBINABLE := true;
			end;
		    end (*constant top*)
		else if IS_CONSTANT(TOP-1) then
		    begin
		    SHIFTDIST := POWER2(STK[TOP-1].FPA.MEMADR.DSPLMT);
		    with STK[TOP] do
			if (SHIFTDIST>=0) and (FPA.MEMADR.LVL=0) and
			   (FINALIND = IND0) and
			   ((NVPAS=0) or ((NVPAS=1) and
			     (VPA1.VSHIFT+SHIFTDIST <= SFLDMAX) )) then
				COMBINABLE := true;
		    end (*constant second from top*);

		if not COMBINABLE then
		    begin
		    if IS_CONSTANT(TOP-1) and IS_CNST_PLUS_OPND(TOP) then
			begin  (*const*uncomplicated*)
			CONSTPART := STK[TOP].FPA.MEMADR.DSPLMT
				     * STK[TOP-1].FPA.MEMADR.DSPLMT;
			STK[TOP].FPA.MEMADR.DSPLMT := 0;
			IMM_OPERAND (OPND1, STK[TOP-1].FPA.MEMADR.DSPLMT);
			FIT_IN_OPERAND (TOOMUCH2, OPND2, TOP);
			if not (not TOOMUCH2) then ASSERTFAIL('UMPY     001');
			CALCULABLE := true;
			end (*const*uncomplicated*)

		    else if IS_CONSTANT(TOP) and IS_CNST_PLUS_OPND(TOP-1) then
			begin  (*uncomplicated*const*)
			CONSTPART := STK[TOP].FPA.MEMADR.DSPLMT
				     * STK[TOP-1].FPA.MEMADR.DSPLMT;
			STK[TOP-1].FPA.MEMADR.DSPLMT := 0;
			FIT_IN_OPERAND (TOOMUCH1, OPND1, TOP-1);
			if not (not TOOMUCH1) then ASSERTFAIL('UMPY     002');
			IMM_OPERAND (OPND2, STK[TOP].FPA.MEMADR.DSPLMT);
			CALCULABLE := true;
			end (*const*uncomplicated*)
		    else
			begin  (*general case*)
			FIT_IN_OPERAND (TOOMUCH1, OPND1, TOP-1);
			FIT_IN_OPERAND (TOOMUCH2, OPND2, TOP);
			if not TOOMUCH1 and not TOOMUCH2 then
			    begin
			    CONSTPART := 0;
			    CALCULABLE := true;
			    end
			else
			    begin  (*must simplify*)
			    if not TOOMUCH1 then
				SIMPLIFY (TOP)
			    else if not TOOMUCH2 then
				SIMPLIFY (TOP-1)
			    else  (*select one at random*)
				SIMPLIFY (TOP);
			    end (*must simplify*);
			end (*general case*);

		    end (*if not COMBINABLE*)
	    until COMBINABLE or CALCULABLE;

	    if CALCULABLE then
		begin
		MULT_SINGLE (DEST, OPND1, OPND2, TOP-1);
		FREEREGSBUTTHESE (TOP, [DEST]);
		POPTOP;
		FREEREGSBUTTHESE (TOP, [DEST]);
		REG_DATUM (TOP, RESCODESTART, RESTYPE, DEST);
		STK[TOP].FPA.MEMADR.DSPLMT := CONSTPART;
		end (*CALCULABLE*)

	    else
		begin  (*COMBINABLE*)
		STK[TOP-1].FPA.MEMADR.DSPLMT :=
		    STK[TOP-1].FPA.MEMADR.DSPLMT * STK[TOP].FPA.MEMADR.DSPLMT;
		if (STK[TOP-1].NVPAS=0) and (STK[TOP].NVPAS<>0) then
		    begin
		    STK[TOP-1].NVPAS := STK[TOP].NVPAS;
		    STK[TOP-1].VPA1 := STK[TOP].VPA1;
		    (*Multiplicands not combinable if 2 VPAs exist*)
		    end;
		with STK[TOP-1] do
		    begin
		    if not (NVPAS <= 1) then ASSERTFAIL('UMPY     003');
		    if NVPAS = 1 then
			VPA1.VSHIFT := VPA1.VSHIFT + SHIFTDIST;
		    CODESTART := RESCODESTART;
		    end;
		POPTOP;
		end (*COMBINABLE*);

	    end (*TYPUJ TYPUL*)

	end (*UMPY I*) else

    if IS_REAL[TYP] then
	begin
	RESCODESTART := STK[TOP-1].CODESTART;
	RESTYPE := STK[TOP-1].DTYPE;
	RESDBL := IS_DOUBLE[RESTYPE];
	if IS_CONSTANT(TOP) and IS_CONSTANT(TOP-1) then
	    begin
	    if not (RESTYPE = TYPUR) then ASSERTFAIL('UMPY     004');
	    STK[TOP-1].RCNST := STK[TOP-1].RCNST * STK[TOP].RCNST;
	    POPTOP;
	    end
	else (*not both constants*)
	    begin
	    S1OP := REAL_ARITH_OP[S1SIZE[RESTYPE],OPC];
	    GET_OPERAND(OPND1,TOP-1);
	    GET_OPERAND(OPND2,TOP);
	    ALLOC_AND_EMIT_TOP(DEST, S1OP, OPND1, OPND2,
			       RESDBL, RESDBL, RESDBL, TOP-1);
	    FREEREGSBUTTHESE(TOP,[DEST]); 
	    POPTOP; 
	    FREEREGSBUTTHESE(TOP,[DEST]);
	    REG_DATUM(TOP,RESCODESTART,RESTYPE,DEST)
	    end (*not both constants*);
	end (*IS_REAL*)

    else ERROR(WARITH_ON_WRONG_DT);

    end (*UMPY*);


USQR :			(* als/peg 28jun79 *)

    with STK[TOP] do
	begin
	if DTYPE <> TYP then  ERROR(WINSTR_TYPE_NOT_DATUM_TYPE);
	if not (IS_REAL[TYP] or IS_INTEGER[TYP]) then
		ERROR(WSQUARE_OF_INVALID_TYPE)
	else
	    begin
	    if IS_CONSTANT(TOP) then
		begin
		if TYP in [TYPUI, TYPUK] then ERROR(WNOT_IMPLEMENTED);
		if IS_INTEGER[TYP] then
		    FPA.MEMADR.DSPLMT := sqr(FPA.MEMADR.DSPLMT)
		else (*IS_REAL(RESTYPE)*)
		    RCNST := sqr(RCNST)
		end (*IS_CONSTANT(TOP)*)
	    else (*not constant*)
		begin
		GET_OPERAND(OPND2,TOP);
		if	((TYP = TYPUJ) or (TYP = TYPUL)) then S1OP := XMULT_S
		else if ((TYP = TYPUI) or (TYP = TYPUK)) then S1OP := XMULT_D
		else if TYP = TYPUR then S1OP := XFMULT_S
		else if TYP = TYPUQ then S1OP := XFMULT_D
		else ASSERTFAIL('UMPY     005');
		ALLOC_AND_EMIT_TOP (DEST, S1OP, OPND2, OPND2,
		    IS_DOUBLE[TYP],IS_DOUBLE[TYP], IS_DOUBLE[TYP], TOP);
		FREEREGSBUTTHESE(TOP,[DEST]);
		REG_DATUM(TOP,CODESTART,TYP,DEST);
		end (*not constant*);
	    end;
	end (*with STK[TOP] do*);

end (*case OPC of*)
end (*ARITH_3_OPS*);

(*** ANI_CLASS:	ARITH_4_OPS UDIV UDMD UMOD ***)
(**)
    

procedure ARITH_4_OPS;
begin
case OPC of (*UDIV, UDMD, UMOD*)


UDIV, UDMD, UMOD :		(* als/peg 03jul79 *)

    begin
    if STK[TOP].DTYPE <> TYP then ERROR(WINSTR_TYPE_NOT_DATUM_TYPE);
    if STK[TOP].DTYPE <> STK[TOP-1].DTYPE then
	  ERROR(WBINARY_OPND_TYPE_CONFLICT);
    if IS_INTEGER[TYP] then
	begin
	RESCODESTART := STK[TOP-1].CODESTART;
	RESTYPE := STK[TOP-1].DTYPE;
	RESDBL := IS_DOUBLE[RESTYPE];
	if IS_CONSTANT(TOP-1) and IS_CONSTANT(TOP) then
	    begin
	    if RESDBL then ERROR(WNOT_IMPLEMENTED);
	    if STK[TOP].FPA.MEMADR.DSPLMT = 0 then
		ERROR(WINTEGER_CONSTANT_DIV_MOD_BY_ZERO)
	    else if OPC = UDMD then
		begin
		STK[TMPD1].FPA.MEMADR.DSPLMT :=
		    STK[TOP-1].FPA.MEMADR.DSPLMT div STK[TOP].FPA.MEMADR.DSPLMT;
		STK[TOP].FPA.MEMADR.DSPLMT :=
		    STK[TOP-1].FPA.MEMADR.DSPLMT mod STK[TOP].FPA.MEMADR.DSPLMT;
		STK[TOP-1].FPA.MEMADR.DSPLMT := STK[TMPD1].FPA.MEMADR.DSPLMT;
		end
	    else
		begin
		if OPC = UDIV then STK[TOP-1].FPA.MEMADR.DSPLMT :=
		    STK[TOP-1].FPA.MEMADR.DSPLMT div STK[TOP].FPA.MEMADR.DSPLMT
		else STK[TOP-1].FPA.MEMADR.DSPLMT :=
		    STK[TOP-1].FPA.MEMADR.DSPLMT mod STK[TOP].FPA.MEMADR.DSPLMT;
		POPTOP
		end
	    end
	else (*not both constants*)
	    begin
	    if OPC = UDMD then            (* peg 03jul79...*)
		begin
		if RESDBL then 
		    begin
		    ERROR(WNOT_IMPLEMENTED);
%		    S1OP := XDIV_D;
		    FINDRGBLOCK(4);
		    DEST1 := NXTRG;
		    DEST2 := NXTRG + 2;
		    FREERG_S(DEST1);
		    ALLOCRP(DEST1);
		    ALLOCRP(DEST2);	\(* als/peg 01aug79 *)
		    end
		else
		    begin
		    S1OP := XDIV_S;
		    FINDRP;
		    DEST1 := NXTRG;
		    DEST2 := NXTRG + 1;
		    FREERG_S(DEST1);
		    ALLOCRG(DEST1);
		    ALLOCRG(DEST2);
		    end;

		REG_OPERAND(OPNDR1, DEST1);
		REG_OPERAND(OPNDR2, DEST2);
		GET_OPERAND(OPND1, TOP-1);
		GET_OPERAND(OPND2, TOP);
		EMITXOP(MOV_X_X[RESTYPE], OPNDR1, OPND1);
		EMITTOP(S1OP, 0, OPNDR1, OPND2);
		FREEREGSBUTTHESE(TOP-1, [DEST1, DEST2]);
		FREEREGSBUTTHESE(TOP, [DEST1, DEST2]);
		REG_DATUM(TOP-1, RESCODESTART, RESTYPE, DEST1);
		REG_DATUM(TOP, RESCODESTART, RESTYPE, DEST2);
		end                       (*...peg 03jul79 *)
	    else 
		begin
		if OPC = UDIV then
		    if RESDBL then S1OP := XQUO_D
		    else S1OP := XQUO_S
		else (*OPC = UREM*)
		    if RESDBL then S1OP := XREM_D
		    else S1OP := XREM_S;
		GET_OPERAND(OPND1,TOP-1);
		GET_OPERAND(OPND2,TOP);
		ALLOC_AND_EMIT_TOP(DEST,S1OP,OPND1,OPND2,
				   RESDBL, RESDBL, RESDBL, TOP-1);
		FREEREGSBUTTHESE(TOP,[DEST]); 
		POPTOP; 
		FREEREGSBUTTHESE(TOP,[DEST]);
		REG_DATUM(TOP, RESCODESTART, RESTYPE, DEST)
		end
	    end (*not both constants*)
		  
	end (*IS_INTEGER, UMOD, UDMD*) else

    if ((IS_REAL[TYP]) and (OPC = UDIV)) then
	begin
	RESCODESTART := STK[TOP-1].CODESTART;
	RESTYPE := STK[TOP-1].DTYPE;
	RESDBL := IS_DOUBLE[RESTYPE];
	if IS_CONSTANT(TOP) and IS_CONSTANT(TOP-1) then
	    begin
	    if not (RESTYPE = TYPUR) then ASSERTFAIL('ARITH_4  001');
		begin
		if STK[TOP].RCNST = 0 then
		    ERROR(WREAL_CONSTANT_DIVISION_BY_ZERO)
		else STK[TOP-1].RCNST := STK[TOP-1].RCNST / STK[TOP].RCNST
		end;
	    POPTOP
	    end
	else (*not both constants*)
	    begin
	    S1OP := REAL_ARITH_OP[S1SIZE[RESTYPE],OPC];
	    GET_OPERAND(OPND1,TOP-1);
	    GET_OPERAND(OPND2,TOP);
	    ALLOC_AND_EMIT_TOP(DEST, S1OP, OPND1, OPND2,
			       RESDBL, RESDBL, RESDBL, TOP-1);
	    FREEREGSBUTTHESE(TOP,[DEST]); 
	    POPTOP; 
	    FREEREGSBUTTHESE(TOP,[DEST]);
	    REG_DATUM(TOP,RESCODESTART,RESTYPE,DEST)
	    end (*not both constants*)
	end (*IS_REAL*)

    else ERROR(WARITH_ON_WRONG_DT);
    end (*UDIV,UDMD,UMOD*);

end (*case OPC of*)
end (*ARITH_4_OPS*);

(*** ANI_CLASS:	COMPARE_SETS REL_OPS UEQU UGEQ UGRT ULEQ ULES UNEQ UIEQU UIGEQ UIGRT UILEQ UILES UINEQ ***)
(**)


procedure COMPARE_SETS;                     (*peg 03jul79...*)
    (*Do the comparisons UEQU, UNEQ, UGEQ, and ULEQ for TYPUS operands.
	GEQ is 'optimized' to an LEQ with the operands reversed
	(GEQ and LEQ are the set inclusion operators; LEQ is thus
	implemented as an AND RSET,SET1,SET2 followed by 
	EQU BOOL,RSET,SET2).*)

    var	BOOL :  boolean;

    begin
    if (STK[TOP-1].DTYPE <> TYPUS) or (STK[TOP].DTYPE <> TYPUS) then
	ERROR (WCOMPARE_ILLEGAL)
    else if not (OPC in [UEQU, UNEQ, UGEQ, ULEQ]) then
	ERROR (WWRONG_COMPARE)
    else
	begin                               (*setch...*)
	if IS_CONSTANT(TOP-1) and IS_CONSTANT(TOP)
	  and ((OPC = UEQU) or (OPC = UNEQ)) then
	    begin
	    if      OPC = UEQU then
		BOOL := STK[TOP-1].SCNST = STK[TOP].SCNST
	    else if OPC = UNEQ then
		BOOL := STK[TOP-1].SCNST <> STK[TOP].SCNST
	    else if not (false) then ASSERTFAIL('COMPARE_S001');

	    POPTOP;  STK[TOP] := ZERODATUM;
	    with STK[TOP] do
		begin
		DTYPE := TYPUB;
		BREPRES := BINTVAL;
		FPA.WHICH := MEM;
		FPA.MEMADR.LVL := 0;
		FPA.MEMADR.DSPLMT := ord(BOOL);
		end (*with STK[TOP] do*);
	    end (*if constants*)

	else
	    begin (*not constant*)
	    LOADSTACKEXCEPT(TOP-1, TOP);
	    RESCODESTART := STK[TOP-1].CODESTART;
	    TMPJUMPLIST := EMPTYJUMPLIST;
	    if OPC = UGEQ then
		begin
		XCHANGE_STKENTS(TOP, TOP-1);
		OPC := ULEQ;
		end;

	    if OPC = ULEQ then
		begin
		FINDRGBLOCK(NUMOFSETPARTS*2);
		DEST := NXTRG;
		for I := 0 to (1 + SETPART_MAX*2) do
		    DESTREGS := DESTREGS + [DEST + I];
		if not RISFREE[S1RTB] then MOVE_AND_FREE_RTB;
		ALLOCRP(S1RTB);
		for INDEX := 0 to SETPART_MAX do
		    begin
		    WHICHPART := INDEX;
		    GET_OPERAND(OPND1,TOP-1);
		    GET_OPERAND(OPND2,TOP);
		    EMITTOP(XAND_D, 3, OPND1, OPND2);   (*Result ==> RTB*)
		    REG_OPERAND(OPNDR, DEST + INDEX*2);
		    EMITXOP(XMOVMS_2, OPNDR, OPNDRTB);
		    end;

		WHICHPART := 0;
		FREERG_S(S1RTB);
		FREEREGSBUTTHESE(TOP-1,DESTREGS);
		REG_DATUM(TOP-1, STK[TOP-1].CODESTART, TYPUS, DEST);
		end (*if OPC = ULEQ*);

	    if not RISFREE[S1RTB] and (RTBUSER < TOP-1) then
		MOVE_AND_FREE_RTB;

	    for INDEX := 0 to SETPART_MAX do
		begin
		WHICHPART := INDEX;
		GET_OPERAND(OPND1,TOP-1);
		GET_OPERAND(OPND2,TOP);
		SKIPLOC := NEWINSTREC;
		EMITSOP (XSKP_EQL_D, 0, OPND1, OPND2, nil);
		JUMPLOC := NEWINSTREC;
		EMITJOP (XJMPA, 0, UNUSED_OP, ZERO_OP, nil);
		if INDEX < SETPART_MAX then
		    AP_JUMP_TO_JUMPLIST(TMPJUMPLIST, JUMPLOC);
		FIXSOP (SKIPLOC, NEWINSTREC);
		end;

	    WHICHPART := 0;
	    FREEDATUMREGS(TOP-1);
	    FREEDATUMREGS(TOP);
	    POPTOP;
	    STK[TOP] := ZERODATUM;
	    with STK[TOP] do
		begin
		CODESTART := RESCODESTART;
		DTYPE := TYPUB;
		BREPRES := BJUMP;
		NVPAS := 1;  (*to make it not look
			    like a constant.  Not needed?*)
		FINDRG;
		VPA1.VPA.WHICH := RGS;
		VPA1.VPA.RGADR := NXTRG;
			  (*where it will go if it becomes bintval*)
		if OPC = UNEQ then
		    begin
		    BFALSELIST := EMPTYJUMPLIST;
		    BTRUELIST := TMPJUMPLIST;
		    BJUMPON := true;
		    end
		else		(*OPC in [UEQU, ULEQ, UGEQ]*)
		    begin
		    BFALSELIST := TMPJUMPLIST;
		    BTRUELIST := EMPTYJUMPLIST;
		    BJUMPON := false;
		    end;
		BFALLTHRUSKIPLOC := SKIPLOC;
		end (*with STK[TOP] do*);

	    end (*not constant*)
	end 				    (*...setch*)
    end (*COMPARE_SETS*);                   (*...peg 15MAY79*)


procedure REL_OPS;
begin
case OPC of

UEQU, UNEQ, UGEQ, UGRT, ULEQ, ULES,		(* als/peg 03jul79 *)
UIEQU, UINEQ, UIGEQ, UIGRT, UILEQ, UILES :

    begin
    if not (TYP in [TYPUA, TYPUB, TYPUC, TYPUI, TYPUJ,
		    TYPUK, TYPUL, TYPUM, TYPUQ, TYPUR, TYPUS]) then
	ERROR(WWRONG_INSTR_DATATYPE);

    if (OPC = UIEQU) or (OPC = UINEQ) or (OPC = UIGEQ)
      or (OPC = UIGRT) or (OPC = UILEQ) or (OPC = UILES) then
	begin
	for STE := TOP-1 to TOP do
	    with STK[STE] do
		begin
		INC_INDIRECTION(STE, IND1);
		DTYPE := TYP;
		DLENGTH := I1;
		end (*with STK[STE] do*);

	case OPC of
	    UIEQU :  OPC := UEQU;
	    UINEQ :  OPC := UNEQ;
	    UIGEQ :  OPC := UGEQ;
	    UIGRT :  OPC := UGRT;
	    UILEQ :  OPC := ULEQ;
	    UILES :  OPC := ULES;
	    end (*case*)

	end (*UIEQU...UILES*);

    if TYP = TYPUS then COMPARE_SETS
    else 
      begin (*TYP <> TYPUS*)
      if TYP <> TYPUM then
	begin
	if TYP in [TYPUJ, TYPUL] then
	    begin
	    COERCE_INT_DATUM(TOP-1);
	    COERCE_INT_DATUM(TOP);
	    end;

	RESTYPE := COMPARE_COERCE_TYPE
		   [STK[TOP-1].DTYPE, STK[TOP].DTYPE];
	if RESTYPE = ILLCOMP then
	    ERROR (WCOMPARE_ILLEGAL)
	else if RESTYPE <> TYP then
	    ERROR (WWRONG_COMPARE);

	RESCODESTART := STK[TOP-1].CODESTART;
	COERCE_DATUM (TOP-1, RESTYPE);
	COERCE_DATUM (TOP, RESTYPE);
	if (RESTYPE in [TYPUA, TYPUI, TYPUJ, TYPUK, TYPUL]) and
	  (STK[TOP-1].FINALIND=IND0) and (STK[TOP].FINALIND=IND0) then
	    begin  (*Bring constant parts to one side.*)
	    if not ((STK[TOP-1].FPA.WHICH = MEM) and
		    (STK[TOP].FPA.WHICH = MEM)) then
                ASSERTFAIL('REL_OPS  001');
	    STK[TOP].FPA.MEMADR.DSPLMT :=
		STK[TOP].FPA.MEMADR.DSPLMT - STK[TOP-1].FPA.MEMADR.DSPLMT;
	    STK[TOP-1].FPA.MEMADR.DSPLMT := 0;
	    end (*Bring constant parts to one side.*);

	if RESTYPE = TYPUB then
	    begin
	    if STK[TOP-1].BREPRES = BJUMP then
		BJUMP_TO_BINTVAL (TOP-1);
	    if STK[TOP].BREPRES = BJUMP then
		BJUMP_TO_BINTVAL (TOP);
	    (*Note : <=,>=,<,> could be optimized as and, or are.*)
	    end;

	S1OP := COMPARE_OP[S1SIZE[RESTYPE], OPC];
	GET_OPERAND (OPND1, TOP-1);
	GET_OPERAND (OPND2, TOP);
	LOADSTACKEXCEPT (TOP-1, TOP);
	if not RISFREE[S1RTB] and (RTBUSER < TOP-1) then
	    MOVE_AND_FREE_RTB;
	FREEDATUMREGS (TOP);
	POPTOP;
	FREEDATUMREGS (TOP);
	end (*TYP<>TYPUM*)
    else
	begin  (*TYP = TYPUM*)
	if not(STK[TOP-1].DTYPE in [TYPUA, TYPUM]) or
	   not(STK[TOP].DTYPE in [TYPUA, TYPUM]) then
	    ERROR (WCOMPM_NEEDS_ADDR);

	(* make sure the zero and CPLPL global are free (to prevent errors) *)
	ALLOCGBL (S1GBLZ);
	OP1GBL := S1GCPLPL;
        ALLOCGBL (OP1GBL);
	OP1GBL := succ(OP1GBL);
	ALLOCGBL (OP1GBL);
	OP1GBL := succ(OP1GBL);
	ALLOCGBL (OP1GBL);
	OP1GBL := succ(OP1GBL);
	ALLOCGBL (OP1GBL);
	OP1GBL := succ(OP1GBL);
	ALLOCGBL (OP1GBL);

	(* initialize the global zero *)
	OP1GBL := S1GBLZ;
	ADDR_OPERAND (OPND1, OP1GBL*WORDUNITS);
	EMITXOP (XMOV_S_S, OPND1, ZERO_OP);

	(* initialize the CPLPL block-descriptor *)
	OP1GBL := S1GCPLPL;
	ADDR_OPERAND (OPND1, OP1GBL*WORDUNITS);
	IMM_OPERAND (OPND2, S1GBLZ*WORDUNITS);
	EMITXOP (XMOV_S_S, OPND1, OPND2);

	OP1GBL := succ(OP1GBL);
	ADDR_OPERAND (OPND1, OP1GBL*WORDUNITS);
	MOVE_QUANTITY (OPND1, TOP-1);

	OP1GBL := succ(OP1GBL);
	ADDR_OPERAND (OPND1, OP1GBL*WORDUNITS);
	IMM_OPERAND (OPND2, I1);
	EMITXOP (XMOV_S_S, OPND1, OPND2);

	OP1GBL := succ(OP1GBL);
	ADDR_OPERAND (OPND1, OP1GBL*WORDUNITS);
	MOVE_QUANTITY (OPND1, TOP);

	OP1GBL := succ(OP1GBL);
	ADDR_OPERAND (OPND1, OP1GBL*WORDUNITS);
	IMM_OPERAND (OPND2, I1);
	EMITXOP (XMOV_S_S, OPND1, OPND2);

	(* emit the BLKCMP and subsequent flag test *)
	ADDR_OPERAND (OPND2, S1GCPLPL*WORDUNITS);			(*LCW*)
	FREEDATUMREGS(TOP);                                     (*EJG 16JAN79*)
	FREEDATUMREGS(TOP-1);                                   (*EJG 16JAN79*)
	FINDRG;
	OP1RG := NXTRG;
	REG_OPERAND (OPND1, OP1RG);
	EMITXOP (BLKCMP_X_Q[OPC], OPND1, OPND2);
	DEST := OP1RG;
	LOADSTACKEXCEPT (TOP-1, TOP);
	POPTOP;
	REG_OPERAND (OPND1, DEST);
	IMM_OPERAND (OPND2, S1TRUEFLAG);
	S1OP := XSKP_EQL_S;
	if not RISFREE[S1RTB] then MOVE_AND_FREE_RTB;
	FREERG_S (DEST);

	(* free the global zero and CPLPL global *)
        FREEGBL_S (S1GBLZ);
	OP1GBL := S1GCPLPL;
        FREEGBL_S (OP1GBL);
	OP1GBL := succ(OP1GBL);
	FREEGBL_S (OP1GBL);
	OP1GBL := succ(OP1GBL);
	FREEGBL_S (OP1GBL);
	OP1GBL := succ(OP1GBL);
	FREEGBL_S (OP1GBL);
	OP1GBL := succ(OP1GBL);
	FREEGBL_S (OP1GBL);
	end (*TYPUM*);

    SKIPLOC := NEWINSTREC;
    EMITSOP (S1OP, 0, OPND1, OPND2, nil);
    EMITJOP (XJMPA, 0, UNUSED_OP, ZERO_OP, nil);
    FIXSOP (SKIPLOC, NEWINSTREC);

    STK[TOP] := ZERODATUM;
    with STK[TOP] do
	begin
	CODESTART := RESCODESTART;
	DTYPE := TYPUB;
	NVPAS := 1;  (*make it not look like a constant.  Not needed?*)
	FINDRG;
	VPA1.VPA.WHICH := RGS;
	VPA1.VPA.RGADR := NXTRG;
			  (*where it will go if it becomes bintval*)
	BREPRES := BJUMP;
	BTRUELIST := EMPTYJUMPLIST;
	BFALSELIST := EMPTYJUMPLIST;
	BJUMPON := false;
	BFALLTHRUSKIPLOC := SKIPLOC;
	end (*with STK[TOP] do*);

    end (*TYP <> TYPUS*)
  end (*UEQU,...,UILES*);


end (*case OPC of*)
end (*REL_OPS*);

(*** ANI_CLASS:	BOOL_OPS UAND UIOR UXOR UNOT UODD ***)
(**)


procedure BOOL_OPS;
begin
case OPC of

UAND, UIOR, UXOR :		(* als/peg 03jul79 *)

    begin
    if STK[TOP].DTYPE <> TYP then ERROR(WINSTR_TYPE_NOT_DATUM_TYPE);
    if STK[TOP].DTYPE <> STK[TOP-1].DTYPE then
	  ERROR(WBINARY_OPND_TYPE_CONFLICT);
    if TYP <> TYPUB then  ERROR (WANDOR_NEEDS_BOOLEAN);

    if IS_CONSTANT(TOP) and IS_CONSTANT(TOP-1) then
	begin
	case OPC of
	    UAND :
	      STK[TOP-1].FPA.MEMADR.DSPLMT :=
		ord((STK[TOP-1].FPA.MEMADR.DSPLMT = 1)
		  and (STK[TOP].FPA.MEMADR.DSPLMT = 1));
	    UIOR :
	      STK[TOP-1].FPA.MEMADR.DSPLMT :=
		ord((STK[TOP-1].FPA.MEMADR.DSPLMT = 1)
		  or (STK[TOP].FPA.MEMADR.DSPLMT = 1));
	    UXOR :
	      STK[TOP-1].FPA.MEMADR.DSPLMT :=
		ord( ((STK[TOP-1].FPA.MEMADR.DSPLMT = 1)
		   or (STK[TOP].FPA.MEMADR.DSPLMT = 1))
	      and not((STK[TOP-1].FPA.MEMADR.DSPLMT = 1)
		      and (STK[TOP].FPA.MEMADR.DSPLMT = 1)) );
		  
	    end (*case*);
	POPTOP;
	end (*constant bintvals*)

    else
	begin  (*non-constant bintvals*)
	if STK[TOP-1].BREPRES = BJUMP then BJUMP_TO_BINTVAL(TOP-1);
	if STK[TOP].BREPRES = BJUMP then BJUMP_TO_BINTVAL(TOP);
	    (* Eliminate codeforks.*)
	RESCODESTART := STK[TOP-1].CODESTART;
	if OPC = UAND then S1OP := XAND_Q
	else if OPC = UIOR then S1OP := XOR_Q
	else S1OP := XXOR_Q;
	GET_OPERAND (OPND1, TOP-1);
	GET_OPERAND (OPND2, TOP);
	ALLOC_AND_EMIT_TOP (DEST, S1OP, OPND1, OPND2,
			    false, false, false, TOP-1);
	FREEREGSBUTTHESE (TOP, [DEST]);
	POPTOP;
	FREEREGSBUTTHESE (TOP, [DEST]);
	REG_DATUM (TOP, RESCODESTART, TYPUB, DEST);
	STK[TOP].BREPRES := BINTVAL;
	end (*non-constant bintvals*);

    end (*UAND, UIOR, UXOR*);


UNOT :			(* als/peg 03jul79 *)
    with STK[TOP] do
	begin
	if DTYPE <> TYPUB then
	    ERROR (WNOT_NEEDS_BOOLEAN);
	RESCODESTART := CODESTART;

	if BREPRES = BJUMP then
	    begin
	    TMPJUMPLIST := BTRUELIST;
	    BTRUELIST := BFALSELIST;
	    BFALSELIST := TMPJUMPLIST;
	    BJUMPON := not BJUMPON;
	    end (*BJUMP*)

	else
	    begin  (*BINTVAL*)
	    if IS_CONSTANT(TOP) then
		FPA.MEMADR.DSPLMT := 1 - FPA.MEMADR.DSPLMT
	    else
		begin  (*non-constant bintval*)
		GET_OPERAND (OPND1, TOP);
		IMM_OPERAND (OPND2, 1);
		ALLOC_AND_EMIT_TOP (DEST, XXOR_Q, OPND1, OPND2,
				    false, false, false, TOP);
		FREEREGSBUTTHESE (TOP, [DEST]);
		REG_DATUM (TOP, CODESTART, TYPUB, DEST);
		BREPRES := BINTVAL;
		end (*non-constant bintval*);
	    end (*BINTVAL*);
	end (*UNOT*);


UODD :			(* als/peg 03jul79 *)

    with STK[TOP] do
	begin
	if not IS_INTEGER[DTYPE] then
	    ERROR(WODD_REQUIRES_AN_INTEGER);
	if IS_CONSTANT(TOP) then
	    begin
	    DTYPE := TYPUB;
	    BREPRES := BINTVAL;
	    FPA.MEMADR.DSPLMT := ord(odd(FPA.MEMADR.DSPLMT))
	    end
	else
	    begin (*not constant*)
	    RESCODESTART := CODESTART;
	    GET_OPERAND(OPND1,TOP);
	    IMM_OPERAND(OPND2,1);
	    LOADSTACKEXCEPT(TOP, TOP);
	    if not RISFREE[S1RTB] and (RTBUSER <> TOP) then
		MOVE_AND_FREE_RTB;
	    FREEDATUMREGS(TOP);
	    SKIPLOC := NEWINSTREC;
	    EMITSOP(SKP_NON_X[DTYPE],0,OPND1,OPND2,nil);
	    EMITJOP(XJMPA,0,UNUSED_OP,ZERO_OP,nil);
	    FIXSOP(SKIPLOC,NEWINSTREC);
	    STK[TOP] := ZERODATUM;
	    CODESTART := RESCODESTART;
	    DTYPE := TYPUB;
	    BREPRES := BJUMP;
	    NVPAS := 1; (*To make it not look like a constant.
			Hopefully not needed.*)
	    FINDRG;
	    VPA1.VPA.WHICH := RGS;
	    VPA1.VPA.RGADR := NXTRG;
			      (*where it will go if it becomes bintval*)
	    BTRUELIST := EMPTYJUMPLIST;
	    BFALSELIST := EMPTYJUMPLIST;
	    BJUMPON := true;
	    BFALLTHRUSKIPLOC := SKIPLOC;
	    end (*not constant*)
    end (*UODD*);

end (*case OPC of*)
end (*BOOL_OPS*);

(*** ANI_CLASS:	SET_OPS UDIF UINT UUNI UINN USGS UADJ UMUS ***)
(**)


procedure SET_OPS;
begin
case OPC of

UDIF, UINT, UUNI :		(* als/peg 05jul79 *)

    begin
    if (STK[TOP-1].DTYPE <> TYPUS) or (STK[TOP].DTYPE <> TYPUS) then
	ERROR(WSET_OPERATION_ON_NONSET_TYPES)
    else
	if IS_CONSTANT(TOP-1) and IS_CONSTANT(TOP) then
	    begin
	    if	    OPC = UDIF then
(*setch*)	SET_DIF(STK[TOP-1].SCNST, STK[TOP-1].SCNST, STK[TOP].SCNST)
	    else if OPC = UINT then
(*setch*)	SET_INT(STK[TOP-1].SCNST, STK[TOP-1].SCNST, STK[TOP].SCNST)
	    else if OPC = UUNI then
(*setch*)	SET_UNI(STK[TOP-1].SCNST, STK[TOP-1].SCNST, STK[TOP].SCNST)
	    else if not (false) then ASSERTFAIL('UDIF,UINT001');
	    POPTOP
	    end
	else (*not both constants*)
	    begin
	    if	    OPC = UDIF then S1OP := XAND_TC_D
	    else if OPC = UINT then S1OP := XAND_D
	    else if OPC = UUNI then S1OP := XOR_D
	    else if not (false) then ASSERTFAIL('UDIF,UINT002');

	    FINDRGBLOCK(NUMOFSETPARTS*2);			(*setch...*)
	    DEST := NXTRG;
	    for I := 0 to (1 + SETPART_MAX*2) do
		DESTREGS := DESTREGS + [DEST + I];
	    if not RISFREE[S1RTB] then MOVE_AND_FREE_RTB;
	    ALLOCRP(S1RTB);
	    for INDEX := 0 to SETPART_MAX do
		begin
		WHICHPART := INDEX;
		GET_OPERAND(OPND1,TOP-1);
		GET_OPERAND(OPND2,TOP);
		EMITTOP(S1OP, 3, OPND1, OPND2);		(*Result ==> RTB*)
		REG_OPERAND(OPNDR, DEST + INDEX*2);
		EMITXOP(XMOVMS_2, OPNDR, OPNDRTB);
		end;

	    WHICHPART := 0;
	    FREERG_S(S1RTB);
	    FREEREGSBUTTHESE(TOP-1,DESTREGS);
	    FREEREGSBUTTHESE(TOP,DESTREGS);
	    REG_DATUM(TOP-1, STK[TOP].CODESTART, TYPUS, DEST);
	    POPTOP;						(*...setch*)
	    end (*not both constants*)
    end (*UDIF, UINT, UUNI*);


USGS, UINN :			(* als/peg 05jul79 *)

    begin
    if OPC = USGS then STE := TOP else STE := TOP-1;
    with STK[STE] do
	begin
	if not IS_INTEGER[DTYPE] and not (DTYPE in [TYPUB,TYPUC]) then
	    ERROR(WSGS_OR_INN_REQUIRES_INT_CHAR_OR_BOOLEAN);
	if DTYPE in [TYPUB,TYPUC] then
	    begin
	    if (DTYPE = TYPUB) and (BREPRES = BJUMP) then
		BJUMP_TO_BINTVAL(STE);
	    DTYPE := TYPUJ
	    end;

	if IS_CONSTANT(STE) then
	    begin
	    if DTYPE in [TYPUI, TYPUK] then ERROR(WNOT_IMPLEMENTED);
	    if (FPA.MEMADR.DSPLMT < 0) or (FPA.MEMADR.DSPLMT > SET_MAX) then
		ERROR(WCONST_OUT_OF_RANGE_FOR_SET);
	    DTYPE := TYPUS;
	    SCNST := NULL_SET;				(*setch*)
	    BUILD_SET(SCNST, FPA.MEMADR.DSPLMT);	(*setch*)
	    FPA := ZEROFPA;
	    end
	else
	    begin (*not constant*)
	    if DTYPE in [TYPUI, TYPUK] then ERROR(WNOT_IMPLEMENTED);
	    FINDRG;  OPRRG := NXTRG;				(*setch...*)
	    REG_OPERAND(OPNDR,OPRRG);
	    GET_OPERAND(OPND2,STE);
	    EMITXOP(XMOV_S_S, OPNDR, OPND2);
	    FREEREGSBUTTHESE(STE, [OPRRG]);

	    FINDRGBLOCK(NUMOFSETPARTS*2);
	    DEST := NXTRG;
	    for INDEX := SETPART_MAX downto 0 do
		begin
		IMM_OPERAND(OPND2,1);
		REG_OPERAND(OPND1, DEST + INDEX*2);
		EMITXOP(XMOV_D_S,OPND1,OPND2);
		EMITTOP(XSHF_LF_D, 0, OPND1, OPNDR);
		if INDEX > 0 then
		    begin
		    IMM_OPERAND(OPND2, SET_SIZE div NUMOFSETPARTS);
		    EMITTOP(XSUB_S, 0, OPNDR, OPND2);
		    end;
		end;

	    REG_DATUM(STE, CODESTART, TYPUS, DEST);
	    FREERG_S(OPRRG);					(*...setch*)
	    end (*not constant*)
	end (*with STK[STE] do*);

    if OPC = UINN then
	begin
	if STK[TOP].DTYPE <> TYPUS then
	    ERROR(WINN_REQUIRES_SET_ON_TOP_OF_STACK);
	if IS_CONSTANT(TOP-1) and IS_CONSTANT(TOP) then
	    begin
	    with STK[TOP-1] do
		begin
		DTYPE := TYPUB;
		BREPRES := BINTVAL;
		SET_INT(SCNST, SCNST, STK[TOP].SCNST);		(*setch...*)
		FPA.MEMADR.DSPLMT := ord(SCNST <> NULL_SET);
		SCNST := NULL_SET;				(*...setch*)
		end;
	    POPTOP;
	    end
	else
	    begin (*not constants*)
	    LOADSTACKEXCEPT(TOP-1, TOP);
	    if not RISFREE[S1RTB] and (RTBUSER < TOP-1) then
		MOVE_AND_FREE_RTB;
	    RESCODESTART := STK[TOP-1].CODESTART;
	    TMPJUMPLIST := EMPTYJUMPLIST;		(*setch...*)

	    for INDEX := 0 to SETPART_MAX do
		begin
		WHICHPART := INDEX;
		GET_OPERAND(OPND1,TOP-1);
		GET_OPERAND(OPND2,TOP);
		SKIPLOC := NEWINSTREC;
		EMITSOP (XSKP_NON_D, 0, OPND1, OPND2, nil);
		JUMPLOC := NEWINSTREC;
		EMITJOP (XJMPA, 0, UNUSED_OP, ZERO_OP, nil);
		if INDEX < SETPART_MAX then
		    AP_JUMP_TO_JUMPLIST(TMPJUMPLIST, JUMPLOC);
		FIXSOP (SKIPLOC, NEWINSTREC);
		end;

	    WHICHPART := 0;
	    FREEDATUMREGS(TOP-1);
	    FREEDATUMREGS(TOP);				(*...setch*)
	    POPTOP;
	    STK[TOP] := ZERODATUM;
	    with STK[TOP] do
		begin
		CODESTART := RESCODESTART;
		DTYPE := TYPUB;
		BREPRES := BJUMP;
		NVPAS := 1;  (*to make it not look
			    like a constant.  Not needed?*)
		FINDRG;
		VPA1.VPA.WHICH := RGS;
		VPA1.VPA.RGADR := NXTRG;
			  (*where it will go if it becomes bintval*)
		BTRUELIST := TMPJUMPLIST;	(*setch*)
		BFALSELIST := EMPTYJUMPLIST;
		BJUMPON := true;
		BFALLTHRUSKIPLOC := SKIPLOC;
		end (*with STK[TOP] do*);
	    end (*not constants*);

	end (*if OPC = UINN*);

    end (*USGS, UINN*);


UADJ :			(**** Write UADJ, UMUS.*)

    begin
    ERROR (WNOT_IMPLEMENTED);
    end (*UADJ*);


UMUS :

    begin
    ERROR (WNOT_IMPLEMENTED);
    end (*UMUS*);

end (*case OPC of*)
end (*SET_OPS*);

(*** ANI_CLASS:	LOAD1_STORE_OPS ULCA ULDA ULDC ULOD ULDP UILOD UPLOD ***)
(**)


procedure LOAD1_STORE_OPS;
begin
case OPC of

ULCA :
    begin
    if not (TYP in [TYPUB, TYPUC, TYPUI, TYPUJ, TYPUK, TYPUL,
      TYPUM, TYPUQ, TYPUR, TYPUS]) then ERROR(WWRONG_INSTR_DATATYPE);
    if TYP <> TYPUM then ERROR(WNOT_IMPLEMENTED);
    PUSHTOP;  STK[TOP] := ZERODATUM;
    with STK[TOP] do
	begin
	CODESTART := NEWINSTREC;
	DTYPE := TYPUM;
	DLENGTH := I1;
	MTYPE := M_SPACE;
	FPA.WHICH := MEM;
	FPA.MEMADR.LVL := 0;
	FPA.MEMADR.DSPLMT := NXTSTRDISP;
	STARTBIT := NXTSTRDISP mod WORDCHARS * CHARBITS;
	for I := 1 to SLGTH do
	    begin
	    if STARTBIT = 0 then
		EMIT_ZEROS1WORD (STRINGAREA, STRINGAR_CPTR);
	    PUTFIELD (STRINGAR_CPTR↑.CODEWORD, STARTBIT,
				  CHARBITS, ord(SVAL[I])-CHARDIF ); (*CHARDIF*)
	    STARTBIT := (STARTBIT + CHARBITS) mod WORDBITS;
	    end;
	NXTSTRDISP := NXTSTRDISP + SLGTH;
	end (*with STK[TOP] do*);
    end (*PLCA*);


ULDA :			(* peg 03jul79 *)
    begin
    PUSHTOP;  STK[TOP] := ZERODATUM;
    with STK[TOP] do
	begin
	CODESTART := NEWINSTREC;
	DTYPE := TYPUA;
	DLENGTH := WORDUNITS;   (*pn*)
	MTYPE := MTYP;
	FPA.WHICH := MEM;
	FPA.MEMADR.LVL := BLOCKTABLE[I1];
	FPA.MEMADR.DSPLMT := I2;
	TRANSLATE_LVLDSP (FPA, MTYP);
	end (*with STK[TOP] do*);
    end (*ULDA*);


ULDC :			(* peg 03jul79 *)
    begin
    PUSHTOP;  STK[TOP] := ZERODATUM;
    with STK[TOP] do
	begin
	CODESTART := NEWINSTREC;
	DTYPE := TYP;
	DLENGTH := I1;
	MTYPE := DEFAULTMTYPE;
	case TYP of
	    TYPUB :
		begin
		FPA.WHICH := MEM;
		FPA.MEMADR.LVL := 0;
		FPA.MEMADR.DSPLMT := I2;
		BREPRES := BINTVAL;
		end;
	    TYPUC :
		begin
		if SLGTH <> 1 then ASSERTFAIL('ULDC     001');
		FPA.WHICH := MEM;
		FPA.MEMADR.LVL := 0;
		FPA.MEMADR.DSPLMT := ord(SVAL[1]) - CHARDIF;
		end;
	    TYPUJ, TYPUL :
		begin
		FPA.WHICH := MEM;
		FPA.MEMADR.LVL := 0;
		FPA.MEMADR.DSPLMT := I2;
		end;
	    TYPUR :  RCNST := R1;
	    TYPUN :  (*null case*);
	    TYPUS :  SCNST := P1;

	    TYPUA, TYPUP :
		ERROR (WINVAL_TYP_ON_LDC);

	    TYPUI, TYPUK, TYPUM, TYPUQ :
		ERROR (WNOT_IMPLEMENTED);

	    end (*case TYP of*);
	end (*with STK[TOP] do*);
    end (*LDC*);


ULOD :		(* peg 03jul79 *)
    begin
    if (I2 div QWBITS) mod ALIGNBNDRY[TYP] <> 0 then
	ERROR (WALIGNMENT_ERROR);

    PUSHTOP;  STK[TOP] := ZERODATUM;
    with STK[TOP] do
	begin
	CODESTART := NEWINSTREC;
	DTYPE := TYP;
	DLENGTH := I3;
	MTYPE := MTYP;
	NVPAS := 1;
	VPA1.VPAIND := IND1;
	VPA1.VPA.WHICH := MEM;
	VPA1.VPA.MEMADR.LVL := BLOCKTABLE[I1];
	VPA1.VPA.MEMADR.DSPLMT := I2;
	TRANSLATE_LVLDSP (VPA1.VPA, MTYP);
	if TYP = TYPUB then BREPRES := BINTVAL;
	end (*with STK[TOP] do*);
    end (*ULOD*);


ULDP :
    begin
    PUSHTOP;  STK[TOP] := ZERODATUM;
    with STK[TOP] do
	begin
	CODESTART := NEWINSTREC;
	DTYPE := TYPUJ;		
	DLENGTH := 36;
	MTYPE := DEFAULTMTYPE;
	FPA.WHICH := MEM;
	FPA.MEMADR.LVL := 0;
	FPA.MEMADR.DSPLMT := I1;
	end;
    end (*ULDP*);


UILOD :		(* als/peg 03jul79 *)

    begin
    with STK[TOP] do
	begin
	if DTYPE <> TYPUA then
	    if DTYPE = TYPUN then ERROR (WNULLREF)
	    else if DTYPE = TYPUM then ERROR (WLOADING_STRING)
	    else ERROR (WNOT_AN_ADDR);

        if TYP = TYPUE then 
	    begin	    
	    TYP := TYPUJ;
	    I2 := 36;
	    end;

	if not (TYP in [TYPUA, TYPUB, TYPUC, TYPUI, TYPUJ,
			TYPUK, TYPUL, TYPUM, TYPUQ, TYPUR, TYPUS]) then
	    ERROR(WWRONG_INSTR_DATATYPE);
	if FPA.WHICH = RGS then
	    ERROR (WINDEXING_IN_PARMS);

	if I1 = 0 then MAXFINALIND := IND1 else MAXFINALIND := IND0;
	FPA.MEMADR.DSPLMT := FPA.MEMADR.DSPLMT + I1;
	INC_INDIRECTION(TOP, MAXFINALIND);
	DTYPE := TYP;
	DLENGTH := I2;
	end (*with STK[TOP] do*);
    end (*UILOD*);


UPLOD :			(* als/peg 18jul79 *)
    with CURPROCSPEC do
	begin
	if PROCTYPE <> TYP then
	    ERROR (WENT_AND_PLOD_INCONSISTENT);
	if TYP <> TYPUP then
	    begin  (*copy function result to RTB*)
	    PUSHTOP;  STK[TOP] := ZERODATUM;
	    with STK[TOP] do
		begin
		CODESTART := NEWINSTREC;
		DTYPE := TYP;
		DLENGTH := I3;
		MTYPE := MTYP;
		NVPAS := 1;
		VPA1.VPAIND := IND1;
		VPA1.VPA.WHICH := MEM;
		VPA1.VPA.MEMADR.LVL := BLOCKTABLE[I1];
		VPA1.VPA.MEMADR.DSPLMT := I2;
		TRANSLATE_LVLDSP (VPA1.VPA, MTYP);
		if TYP = TYPUB then BREPRES := BINTVAL;
		end (*with STK[TOP] do*);
	    MOVE_QUANTITY(OPNDRTB, TOP);
	    end (*copy function result*);
	end (*UPLOD*);


end (*case OPC of*)
end (*LOAD1_STORE_OPS*);

(*** ANI_CLASS: LOAD2_STORE_OPS USTR UNSTR UISTR UINST UPSTR UMOV ***)
(**)


procedure LOAD2_STORE_OPS;
begin
case OPC of

USTR, UNSTR :		(* als/peg 03jul79 *)

    begin
    if (I2 div QWBITS) mod ALIGNBNDRY[TYP] <> 0 then
	ERROR (WALIGNMENT_ERROR);

    if not (TYP in [TYPUA, TYPUB, TYPUC, TYPUE, TYPUI, TYPUJ,
		    TYPUK, TYPUL, TYPUM, TYPUQ, TYPUR, TYPUS]) then
	ERROR(WWRONG_INSTR_DATATYPE);
  
    if TYP = TYPUE then  (*pn*)
        begin
        TYP := TYPUJ;
        I3 := 36;
	end;

    if not( (STK[TOP].DTYPE = TYP) or
            ((TYP = TYPUA) and (STK[TOP].DTYPE = TYPUN)) ) then
	ERROR(WINSTR_TYPE_NOT_DATUM_TYPE);

    if TYP in [TYPUJ, TYPUL] then
	begin
	CVT_INT_DATUM(TOP);
	TYP := LENGTH_TO_INTOPNDTYPE(I3);
	end;

    STK[TMPD1] := ZERODATUM;
    with STK[TMPD1] do
	begin
	CODESTART := STK[TOP].CODESTART;
	DTYPE := TYPUA;
	DLENGTH := I3;
	MTYPE := MTYP;
	FPA.WHICH := MEM;
	FPA.MEMADR.LVL := BLOCKTABLE[I1];
	FPA.MEMADR.DSPLMT := I2;
	TRANSLATE_LVLDSP (FPA, MTYP);
	end;

    for STE := BOT to TOP do
	LOADSTKENTRY(STE);	(*Prevent side effects*)
    STORE (TMPD1, TOP);
    if OPC = USTR then
	begin
	FREEDATUMREGS (TOP);
	POPTOP;
	end;
 (* FREEDATUMREGS (TMPD1);*)(*This should be superfluous.*)
    end (*USTR, UNSTR*);


UISTR, UINST :		(* als/peg 06jul79 *)
    begin		(* Alignment??*)
    if not (TYP in [TYPUA, TYPUB, TYPUC, TYPUI, TYPUJ,
		    TYPUK, TYPUL, TYPUM, TYPUQ, TYPUR, TYPUS]) then
	ERROR(WWRONG_INSTR_DATATYPE);
    if not( (STK[TOP].DTYPE = TYP) or
            ((TYP = TYPUA) and (STK[TOP].DTYPE = TYPUN)) ) then
	ERROR(WINSTR_TYPE_NOT_DATUM_TYPE);
    if STK[TOP-1].DTYPE <> TYPUA then
	ERROR(WISTR_INST_NEEDS_ADDRS);

    INCREMENT_DATUM(TOP-1, I1);
    if TYP in [TYPUJ, TYPUL] then
	begin
	CVT_INT_DATUM(TOP);
	TYP := LENGTH_TO_INTOPNDTYPE(I2);
	end;

    for STE := BOT to TOP do
	LOADSTKENTRY(STE);	(*Prevent side effects*)
    STORE(TOP-1, TOP);
    FREEDATUMREGS(TOP-1);
    if OPC = UINST then
	begin
	STK[TOP-1] := STK[TOP];
	STK[TOP-1].DLENGTH := I2;
	end
    else (*OPC = UISTR*)
	begin
	FREEDATUMREGS(TOP);
	POPTOP;
	end;
    POPTOP;
    end (*UISTR, UINST*);


UPSTR :			(* als/peg 13jul79 *)
    begin
    PSTRCOUNT := PSTRCOUNT + 1;
    PUSHTOP;  STK[TOP] := ZERODATUM;
    with STK[TOP] do
	begin
	CODESTART := NEWINSTREC;
	DTYPE := TYP;
	DLENGTH := I3;
	MTYPE := MTYP;
	FPA.WHICH := MEM;
	FPA.MEMADR.LVL := BLOCKTABLE[I1];
	FPA.MEMADR.DSPLMT := I2;
	TRANSLATE_LVLDSP (FPA, MTYP);
	end (*with STK[TOP] do*);

    if PSTRCOUNT = CURPROCSPEC.PARMS_POPPED then
	with CURPROCSPEC do
	    begin
	    PWORD := 0;
	    EXCESS := 0;
	    for I := 1 to PARMS_POPPED do
		begin
		if STK[TOP].MTYPE = R_SPACE then
		    if IS_DOUBLE[STK[TOP].DTYPE] then
			PWORD := PWORD + 2
		    else PWORD := PWORD + 1
		else if STK[TOP].MTYPE = M_SPACE then
		    EXCESS := EXCESS + STK[TOP].DLENGTH div WORDBITS
		else ERROR(WNOT_IMPLEMENTED);
		POPTOP;
		end (*for*);

	    REGPARMAREA := PWORD*WORDUNITS;
	    RESERVE_PARMREGS(PWORD);

	    if EXCESS > 0 then
	    (*There were so many parms that we passed some in the caller's
		stackframe regs.  Copy them into the parm save area where
		they belong.  The caller has passed the address of the begin-
		ning of the parameter block in RTB -- peg 13jul79. *)

		if EXCESS <= MAXMOVMS then  (*emit a MOVMS instruction*)
		    begin
		    ALLOCRG(S1RTB);
		    OFFSET := -OFFSET_IN_VARS + DOUBLEWORDUNITS;
			(****This allows for function result, and will
				probably need to be changed for UPAS -- peg*)
		    REGDISP_OPERAND (OPND1, DISPLAY, OFFSET);
		    REGDISP_OPERAND (OPND2, S1RTB, 0);
		    EMITXOP(MOVMS_N[EXCESS], OPND1, OPND2);
		    FREERG_S(S1RTB);
		    end (*emit a MOVMS*)
(**** Note: this should probably use a loop of MOVMS instructions, as
	does MOV (q.v., below); perhaps the code (including the BLKMOV code)
	should be put into a procedure, as it is lengthy -- peg.*)

		else (*emit a BLKMOV*)
		    begin

		    (*make sure that the global zero
			and CPL are free (error if not)*)
		    ALLOCGBL (S1GBLZ);
		    ALLOCRG (S1RCPL);
		    ALLOCRG (succ(S1RCPL));
		    ALLOCRG (succ(succ(S1RCPL)));

		    (* initialize the global zero *)
		    OP1GBL := S1GBLZ;
		    ADDR_OPERAND (OPND1, OP1GBL*WORDUNITS);
		    EMITXOP (XMOV_S_S, OPND1, ZERO_OP);

		    (*initialize the CPL block descriptor*)
		    REG_OPERAND (OPNDR1, S1RCPL);
		    IMM_OPERAND (OPND2, S1GBLZ*WORDUNITS);
		    EMITXOP (XMOV_S_S, OPNDR1, OPND2);

		    (* set up the destination address and length *)
		    REG_OPERAND (OPNDR1, succ(S1RCPL));
		    REGDISP_OPERAND (OPND2, DISPLAY, -OFFSET_IN_VARS);
		    EMITXOP (XMOV_A, OPNDR1, OPND2);

		    REG_OPERAND (OPNDR1, succ(succ(S1RCPL)));
		    IMM_OPERAND (OPND2, EXCESS);
		    EMITXOP (XMOV_S_S, OPNDR1, OPND2);

		    (*emit the BLKMOV*)
		    ALLOCRG(S1RTB);
		    REG_OPERAND (OPNDR1, S1RCPL);
		    REG_OPERAND (OPNDR2, S1RTB);
		    INSTLOC := NEWINSTREC;
		    EMITXOP (XBLKMOV, OPNDR1, OPNDR2);
		    FREERG_S(S1RTB);

		    (*free the global zero and CPL registers*)
		    FREEGBL_S (S1GBLZ);
		    FREERG_S (S1RCPL);
		    FREERG_S (succ(S1RCPL));
		    FREERG_S (succ(succ(S1RCPL)));
		    end (*emit a BLKMOV*);
	    end (*with CURPROCSPEC*);
    end (*UPSTR*);


UMOV :
    begin

    (* LCW 2AUG78
    The strategy for UMOV is to do a BLKMOV if the transfer length is long
    enough to justify the BLKMOV overhead, else to do a series of MOVMQs,
    starting with the longest available MOVMQ and proceeding to the short
    MOVMQs if necessary.

    This procedure ignores the problem associated with having overlapping
    source and destination where the source address is less than the
    destination address.  In that case, SOPA may destroy the source during
    the MOV.  However, if the source and destination overlap completely,
    then SOPA will not destroy the source.  Note that PASCAL and PCode do
    not explicitly define the semantics of MOV when the source and
    destination incompletely overlap.
    *)

    if not (TYP in [TYPUA, TYPUB, TYPUC, TYPUI, TYPUJ,
		    TYPUK, TYPUL, TYPUM, TYPUQ, TYPUR, TYPUS]) then
	ERROR(WWRONG_INSTR_DATATYPE);

    if not (STK[TOP-1].DTYPE in [TYPUA,TYPUM]) or
       not (STK[TOP].DTYPE in [TYPUA,TYPUM]) then
	ERROR (WMOV_NEEDS_ADDRS);

    if I1 mod QWBITS <> 0 then ERROR(WALIGNMENT_ERROR)
    else I1 := I1 div QWBITS;
    if I1 >= BLKMOV_THRESH then
	begin (*generate BLKMOV*)

	(*make sure that the global zero and CPL are free (error if not)*)
	ALLOCGBL (S1GBLZ);
	ALLOCRG (S1RCPL);
	ALLOCRG (succ(S1RCPL));
	ALLOCRG (succ(succ(S1RCPL)));

	(* initialize the global zero *)
	OP1GBL := S1GBLZ;
	ADDR_OPERAND (OPND1, OP1GBL*WORDUNITS);
	EMITXOP (XMOV_S_S, OPND1, ZERO_OP);

	(*initialize the CPL block descriptor*)
	REG_OPERAND (OPNDR1, S1RCPL);
	IMM_OPERAND (OPND2, S1GBLZ*WORDUNITS);
	EMITXOP (XMOV_S_S, OPNDR1, OPND2);

	REG_OPERAND (OPNDR1, succ(S1RCPL));
	MOVE_QUANTITY (OPNDR1, TOP-1);

	REG_OPERAND (OPNDR1, succ(succ(S1RCPL)));
	IMM_OPERAND (OPND2, I1);
	EMITXOP (XMOV_S_S, OPNDR1, OPND2);

	(*emit the BLKMOV*)
	REG_OPERAND (OPNDR1, S1RCPL);
	GET_ADDRESS (OPND2, TOP);
	EMITXOP (XBLKMOV, OPNDR1, OPND2);

	(*free the global zero and CPL registers*)
        FREEGBL_S (S1GBLZ);
	FREERG_S (S1RCPL);
	FREERG_S (succ(S1RCPL));
	FREERG_S (succ(succ(S1RCPL)));

	end (*generate BLKMOV*)

    else

        begin (*generate MOVMQ*)
	XFER_CNT := I1;

	while XFER_CNT >= 128 do
	    begin
	    GET_ADDRESS (OPND1, TOP-1);
	    GET_ADDRESS (OPND2, TOP);
	    EMITXOP (XMOVMQ_128, OPND1, OPND2);
	    XFER_CNT := XFER_CNT - 128;
	    if XFER_CNT > 0 then
		begin
		INCREMENT_DATUM (TOP-1, 128);
		INCREMENT_DATUM (TOP, 128);
		end;
	    end;
	
	if XFER_CNT >= 64 then
	    begin
	    GET_ADDRESS (OPND1, TOP-1);
	    GET_ADDRESS (OPND2, TOP);
	    EMITXOP (XMOVMQ_64, OPND1, OPND2);
	    XFER_CNT := XFER_CNT - 64;
	    if XFER_CNT > 0 then
		begin
		INCREMENT_DATUM (TOP-1, 64);
		INCREMENT_DATUM (TOP, 64);
		end;
	    end;
	
	if XFER_CNT >= 32 then
	    begin
	    GET_ADDRESS (OPND1, TOP-1);
	    GET_ADDRESS (OPND2, TOP);
	    EMITXOP (XMOVMQ_32, OPND1, OPND2);
	    XFER_CNT := XFER_CNT - 32;
	    if XFER_CNT > 0 then
		begin
		INCREMENT_DATUM (TOP-1, 32);
		INCREMENT_DATUM (TOP, 32);
		end;
	    end;
	
	if XFER_CNT > 0 then
	    begin
	    GET_ADDRESS (OPND1, TOP-1);
	    GET_ADDRESS (OPND2, TOP);
	    EMITXOP (MOVMQ_N[XFER_CNT], OPND1, OPND2);
	    end;

	end (*generate MOVMQ*);

    FREEDATUMREGS (TOP);
    POPTOP;
    FREEDATUMREGS (TOP);
    POPTOP;
    end (*PMOV*);


end (*case OPC of*)
end (*LOAD2_STORE_OPS*);

(*** ANI_CLASS:	FLOW_CONTROL_OPS UTJP UFJP UUJP UXJP UGOOB ULAB UCLAB ***)
(**)


procedure FLOW_CONTROL_OPS;
begin
case OPC of

UTJP, UFJP :		(* peg 02jul79 *)
    begin
    if TOP <> BOT then
	ERROR (WTJP_FJP_WITH_NONEMPTY_STACK);
    LABNUM := LABELNUMBER(NAM1);

    with STK[TOP] do
	begin
	if DTYPE <> TYPUB then
	    ERROR (WTJP_FJP_NEEDS_BOOLEAN);

	if BREPRES = BINTVAL then
	    if IS_CONSTANT(TOP) then
		if ((OPC = UTJP) and (FPA.MEMADR.DSPLMT = 1))
		  or ((OPC = UFJP) and (FPA.MEMADR.DSPLMT = 0)) then
		    begin  (*jump always*)
		    JUMPLOC := NEWINSTREC;
		    EMITJOP (XJMPA, 0, UNUSED_OP, ZERO_OP, nil);
		    JMP_TO_LABEL_RECORD_OR_FIX (JUMPLOC, LABNUM);
		    end
		else if ((OPC = UTJP) and (FPA.MEMADR.DSPLMT = 0))
		  or ((OPC = UFJP) and (FPA.MEMADR.DSPLMT = 1)) then
		    (*never jump*)
		else ASSERTFAIL('UTJP,UFJP001')
		
	    else
		begin  (*non-constant bintval*)
		if OPC = UTJP then S1OP := XJMPZ_NEQ_Q
		else S1OP := XJMPZ_EQL_Q;
		GET_OPERAND (OPND1, TOP);
		JUMPLOC := NEWINSTREC;
		EMITJOP (S1OP, 0, OPND1, ZERO_OP, nil);
		JMP_TO_LABEL_RECORD_OR_FIX (JUMPLOC, LABNUM);
		end (*non-constant bintval*)

	else
	    begin  (*bjump representation*)
	    if (BJUMPON and (OPC = UFJP))
	      or ((not BJUMPON) and (OPC = UTJP)) then
		begin
		BFALLTHRUSKIPLOC↑.OPCODE := INVERSE_SKIP[BFALLTHRUSKIPLOC↑.OPCODE];(*DATASTRCH*)
		BJUMPON := not BJUMPON;
		end;
	    if OPC = UFJP then
		PTR := BTRUELIST.FIRST
	    else PTR := BFALSELIST.FIRST;
	    while PTR <> nil do
		begin
		NEXT := PTR↑.DESTPTR;				(*DATASTRCH*)
		FIXJOP (PTR, NEWINSTREC);
		PTR := NEXT;
		end;
	    if OPC = UFJP then
		PTR := BFALSELIST.FIRST
	    else PTR := BTRUELIST.FIRST;
	    while PTR <> nil do
		begin
		NEXT := PTR↑.DESTPTR;				(*DATASTRCH*)
		JMP_TO_LABEL_RECORD_OR_FIX (PTR, LABNUM);
		PTR := NEXT;
		end;
	    FALLTHRUJUMP := BFALLTHRUSKIPLOC↑.NEXTPTR;		(*DATASTRCH*)
	    JMP_TO_LABEL_RECORD_OR_FIX (FALLTHRUJUMP, LABNUM);
	    end (*bjump representation*);

	end (*with STK[TOP] do*);

    FREEDATUMREGS (TOP);
    POPTOP;
    end (*UTJP, UFJP*);


UUJP :		(* als/peg 28jun79 *)
    begin
    if TOP <> BOT-1 then
	ERROR (WUJP_WITH_NONEMPTY_STACK);
    JUMPLOC := NEWINSTREC;
    PR_BIT := ord( JUMPTABLE_IN_PROGRESS );
    EMITJOP (XJMPA, PR_BIT, UNUSED_OP, ZERO_OP, nil);
    JMP_TO_LABEL_RECORD_OR_FIX (JUMPLOC, LABELNUMBER(NAM1));
    end (*UUJP*);


UXJP :			(* peg 05jul79 *)
    begin
    (*XJP compiles into
	       SKP if too small to A
	       SKP if not too big to B
	    A: JUMP to default
	    B: JUMP to wherever(index)	*)

    if TOP <> BOT then
	ERROR (WXJP_WITHOUT_SINGLETON_STACK);
    if not IS_INTEGER[TYP] then
	ERROR (WWRONG_INSTR_DATATYPE);
    if not (TYP = STK[TOP].DTYPE) then
	ERROR (WINSTR_TYPE_NOT_DATUM_TYPE);
    if TYP in [TYPUI, TYPUK] then
	ERROR(WNOT_IMPLEMENTED);

    LABNUM1 := LABELNUMBER(NAM1);
    LABNUM2 := LABELNUMBER(NAM2);
    if TYP in [TYPUJ, TYPUL] then CVT_INT_DATUM(TOP);

    COERCE_DATUM (TOP, TYPUJ);
    if IS_CONSTANT(TOP) then
	begin
	IMM_OPERAND (OPND, STK[TOP].FPA.MEMADR.DSPLMT);
	XTNDED_REGDISP_OPERAND
	    (OPND1, S1RPC,  I1 - STK[TOP].FPA.MEMADR.DSPLMT)
			    (*Looks funny but it is compatible with
				the negate-and-shift fixup which
				must be done in the case of a
				variable index.*)
	end
    else
	begin
	GET_SHORT_OPERAND (OPND, TOP);
	OPND1 := OPND;
	OPND1.X := 1;
	OPND1.XW.V := 1;
	OPND1.XW.S := DALIGNSHIFT;
	OPND1.XW.REG := S1RPC;
	OPND.XW.DISP := -I1;
	end;

    IMM_OPERAND(OPND2, I1);
    SKIPSMALL := NEWINSTREC;
    EMITSOP (XSKP_LSS_S, 0, OPND, OPND2, nil);
    IMM_OPERAND(OPND2, I2);
    SKIPNOTBIG := NEWINSTREC;
    EMITSOP (XSKP_LEQ_S, 0, OPND, OPND2, nil);
    JUMPDEFAULT := NEWINSTREC;
    EMITJOP (XJMPA, 0, UNUSED_OP, ZERO_OP, nil);
    JUMPINDEXED := NEWINSTREC;
    EMITJOP (XJMPA, 0, UNUSED_OP, OPND1, nil);

    FIXSOP (SKIPSMALL, JUMPDEFAULT);
    FIXSOP (SKIPNOTBIG, JUMPINDEXED);
    JMP_TO_LABEL_RECORD_OR_FIX (JUMPDEFAULT, LABNUM2);
    ADD_INSTPTR_TO_OPND2FIXLIST (NEG_SHIFT_FIXLIST, JUMPINDEXED);	(*DATASTRCH*)
	(*All OPND2s on this fixup list will have the displacement
	    in the extended word negated and arithmetically shifted
	    to make it a doubleword index.*)
    JMP_TO_TABLE_RECORD_OR_FIX (JUMPINDEXED, LABNUM1);

    FREEDATUMREGS (TOP);
    POPTOP;
    end (*UXJP*);


UGOOB :
    begin
    (* NOTE: This instruction cuts back the RUNTIME stack, going back through
	the DYNAMIC links to find the correct lexical level.  We'll have to generate
	an external fixup for the linker, since the destination has not been seen
	yet and won't be during this segment -- peg.*)
    ERROR (WNOT_IMPLEMENTED);
    end (*UGOOB*);


ULAB, UCLAB :			(* peg 02jul79 *)
    (* Note: LAB operand, branch count, is in I1. If this value is 1 we might
       rearrange the code, or perhaps the Optimizer should do it. ALS *)
    begin
    if TOP <> BOT - 1 then
	ERROR(WSTACK_NON_EMPTY);
    UPD_LBLTBL (LPTR, LABELNUMBER(NAM0), LINSTPTR);		(*DATASTRCH*)
    with LPTR↑ do
	begin
	if DEFINED then ERROR (WMULT_DEFINED_LAB);
	DEFINED := true;
	if OPC = ULAB then BRANCH_CNT := I1;	(* peg 02jul79 *)
	INSTPTR := NEWINSTREC;					(*DATASTRCH*)
	if JUMPTABLELABEL then JUMPTABLE_IN_PROGRESS := true;
	PTR := JLIST.FIRST;
	while PTR <> nil do
	    begin
	    NEXT := PTR↑.DESTPTR;				(*DATASTRCH*)
	    FIXJOP (PTR, INSTPTR);				(*DATASTRCH*)
	    PTR := NEXT
	    end;
	JLIST := EMPTYJUMPLIST;
	end (*with LPTR↑ do*);

%*  if OPC = UCLAB then		(*What is this garbage???! peg 25jul*)
	begin
	UPD_LBLTBL (LPTR, -1, LINTVAL); (* lower case boundary is always 0 *)
	with LPTR↑ do
	    begin
	    DEFINED := true;
	    INTVAL := 0;
	    FIXOPND2 (CLIST.FIRST↑.OPND2IPTR, INTVAL);		(*DATASTRCH*)
	    CLIST := EMPTYOPND2FIXLIST;				(*DATASTRCH*)
	    end (*with LPTR↑ do*);
	UPD_LBLTBL (LPTR, -2, LINTVAL);  (* upper case boundary *)
	with LPTR↑ do
	    begin
	    DEFINED := true;
	    INTVAL := I1-1;
	    FIXOPND2 (CLIST.FIRST↑.OPND2IPTR, INTVAL);		(*DATASTRCH*)
	    CLIST := EMPTYOPND2FIXLIST;
	    end (*with LPTR↑ do*);
	end;	*\		(*...end garbage*)

    end (*ULAB, UCLAB*);

end (*case OPC of*)
end (*FLOW_CONTROL_OPS*);

(*** ANI_CLASS:	ENVIRONMENT_OPS UBGN UEND USTP UENT UBGNB UENDB ***)
(**)


procedure ENVIRONMENT_OPS;
begin
case OPC of

UBGN :
    begin		(* als/peg 05jul79 *)
    CURPROG := NAM1;
    end (*UBGN*);


USTP :			(* als/peg 05jul79 *)
    begin
    if NAM1 <> CURPROG then
	ERROR(WBGN_STP_NAME_MISMATCH);
    end (*USTP*);


UEND :			(* als/peg 05jul79 *)
    begin
    if NAM1 <> CURPROCXN then
	ERROR(WENT_END_NAME_MISMATCH);
    if PSTRCOUNT <> CURPROCSPEC.PARMS_POPPED then
	ERROR(WENT_SPECIFIED_WRONG_PARMS);
    if TOP > BOT - 1 then
	while TOP >= BOT do POPTOP;
    GEN_SEGMENT;
    end (*UEND*);


UENT :			(* als/peg 13jul79 *)
    begin
    CURPROCXN := NAM0;
    CURLVL := I1;
    CURPROC := NAM0.NAM;
    INIT_SEGMENT;
    PSTRCOUNT := 0;	(* Set here to use as check in UPSTR and UEND. *)

    if I1 <= 0 then
	ERROR (WINVALID_LEVEL)
    else if I1 > MAXLVLUSED then
	begin
	MAXLVLUSED := I1;
	MINDSPS1REG := MAXDSPS1REG - (MAXLVLUSED-1);
	CHECK_DSP_TMP_COLLISION
	end;

    DISPLAY := LVL_TO_S1REG[CURLVL];
    if DISPLAY < MINDSPS1REG then ASSERTFAIL('UENT     001');
    BLOCKTABLE[I2] := CURLVL;
    with CURPROCSPEC do
	begin
	PROCTYPE := TYP;
	PROCNAM := CURPROCXN;
	PARMS_POPPED := I3;
	if PARMS_POPPED = 0 then
	    RESERVE_PARMREGS(0);
	RESULTS_PUSHED := I4;
	REGPARMAREA := 0;
	R_MEMORY_AREA := 0;
	M_MEMORY_AREA := 0;

	if not DEBUG then
	    begin
	    REG_OPERAND (OPNDR, DISPLAY);
	    if CURLVL = 1 then
		XTNDED_REGDISP_OPERAND (OPND2, S1RSP, L1DISPLAY_OFFSET
					  (*+ eval save size by fixup*) )
	    else (*CURLVL > 1*)
		XTNDED_REGDISP_OPERAND (OPND2, S1RSP, DISPLAY_OFFSET
					  (*+ eval save size by fixup*) );
	    INSTLOC := NEWINSTREC;
	    EMITXOP (XMOV_A, OPNDR, OPND2);
	    ADD_INSTPTR_TO_OPND2FIXLIST (EVALSAVE.FIXLIST, INSTLOC);	(*DATASTRCH*)
	    if CURLVL = 1 then
		XTNDED_IMM_OPERAND(OPND2, FILBUFAREASIZE)
	    else (*CURLVL > 1*)
		XTNDED_IMM_OPERAND(OPND2, REGIMAGEAREASIZE);
	    INSTLOC := NEWINSTREC;
	    EMITXOP (XADJSP_UP, OPNDRSP, OPND2);
	    ADD_INSTPTR_TO_OPND2FIXLIST (EVALSAVE.FIXLIST, INSTLOC);	(*DATASTRCH*)
	    ADD_INSTPTR_TO_OPND2FIXLIST (STACKFRAME.FIXLIST, INSTLOC);	(*DATASTRCH*)
    (**** Note: this will have to have the expr. temp. stack and large callee
    parm. area sizes fixed up, too--peg*)
	    end

	else (*DEBUG*)
	    begin  (*allocate extra word for callee segment base save*)
	    REG_OPERAND (OPNDR, DISPLAY);
	    if CURLVL = 1 then
		XTNDED_REGDISP_OPERAND (OPND2, S1RSP,
					L1DISPLAY_OFFSET + WORDUNITS
					  (*+ eval save size by fixup*) )
	    else (*CURLVL > 1*)
		XTNDED_REGDISP_OPERAND (OPND2, S1RSP,
					DISPLAY_OFFSET + WORDUNITS
					  (*+ eval save size by fixup*) );
	    INSTLOC := NEWINSTREC;
	    EMITXOP (XMOV_A, OPNDR, OPND2);
	    ADD_INSTPTR_TO_OPND2FIXLIST (EVALSAVE.FIXLIST, INSTLOC);	(*DATASTRCH*)
	    ADDR_OPERAND (OPND1, S1GSEGBASE*WORDUNITS);
	    if CURLVL = 1 then
		XTNDED_IMM_OPERAND (OPND2, FILBUFAREASIZE + WORDUNITS)
	    else (*CURLVL > 1*)
		XTNDED_IMM_OPERAND (OPND2, REGIMAGEAREASIZE + WORDUNITS);
	    INSTLOC := NEWINSTREC;
	    EMITXOP (XALLOC_1, OPND1, OPND2);
	    ADD_INSTPTR_TO_OPND2FIXLIST (EVALSAVE.FIXLIST, INSTLOC);	(*DATASTRCH*)
	    ADD_INSTPTR_TO_OPND2FIXLIST (STACKFRAME.FIXLIST, INSTLOC);	(*DATASTRCH*)
    (**** And expr. temp. and parm. area lists???*)
	    XTNDED_REGDISP_OPERAND (OPND2, S1RPC, 0);
	    EMITXOP (XMOV_A, OPND1, OPND2);
		(*OPND2 needs to be fixed up by subtracting this
		    instruction's displacement in the segment.  The
		    code concretizer will do this automatically
		    because it normalizes *all* PC-relative addresses
		    to the beginning of the segment.*)
	    end (*allocate extra word*);

	end (*with CURPROCSPEC...*);

    end (*UENT*);


UBGNB :		(* peg 09jul79 *)
    begin
    if CURFRAME >= MAXFRAME then
	ERROR(W2_MANY_BGNBS);
    PUSH_STKFRAME;
    end (*UBGNB*);


UENDB :		(* peg 09jul79 *)
    begin
    if CURFRAME <= MINFRAME then
	ERROR(W2_MANY_ENDBS);
    POP_STKFRAME;
    end (*UENDB*);

end (*case OPC of*)
end (*ENVIRONMENT_OPS*);

(*** ANI_CLASS:	CHECK_OPS UCHKL UCHKH UCHKT UCHKF UCHKN ***)
(**)


procedure CHECK_OPS;
begin
case OPC of

UCHKH, UCHKL :		(* peg 07jul79 *)
    (****Note: peephole optimizer may optimize the case where a CHKL
	is followed immediately by a CHKH on the same item; it may have
	to be done here because of literal table fixup problems.  Also,
	this routine needs to be modified when our error codes are
	standardized -- peg 23sep79.*)
    begin
    if not (STK[TOP].DTYPE in
      [TYPUA, TYPUC, TYPUI, TYPUJ, TYPUK, TYPUL, TYPUN, TYPUS]) then
	ERROR(WCHECKING_INVALID_TYPE);
    if not( (STK[TOP].DTYPE = TYP) or
            ((TYP = TYPUA) and (STK[TOP].DTYPE = TYPUN)) ) then
	ERROR(WINSTR_TYPE_NOT_DATUM_TYPE);
    if TYP in [TYPUI, TYPUK, TYPUS] then ERROR(WNOT_IMPLEMENTED);

    if TYP = TYPUC then
	I1 := I1 + CHARDIF;

    if IS_CONSTANT(TOP) then
	begin
	if ((OPC = UCHKH) and (STK[TOP].FPA.MEMADR.DSPLMT > I1))
	  or ((OPC = UCHKL) and (STK[TOP].FPA.MEMADR.DSPLMT < I1)) then
	    ERROR(WCHECKED_CONSTANT_OUT_OF_RANGE);
	end

    else (*not constant*)
	begin
	if OPC = UCHKH then
	    begin
	    LOWBOUND := MIN_ON_COMP_MACH + 1;	(**** This is a kludge -- *)
	    HIGHBOUND := I1;				(* als/peg 31jul79*)
	    end (*OPC = UCHKH*)
	else (*OPC = UCHKL*)
	    begin
	    LOWBOUND := I1;
	    HIGHBOUND := MAX_ON_COMP_MACH;
	    end;

	GET_OPERAND(OPND2, TOP);
	XTNDED_REGDISP_OPERAND(OPND1, S1RPC, 0);
	UPD_BOUNDTBL(OPND1.XW.DISP, LOWBOUND, HIGHBOUND, TYP);
	OPND1.FIXUP := BOUNDFIX;
	EMITXOP(BTRP_B_X[TYP],OPND1,OPND2);
	end (*not constant*);
    end (*UCHKL, UCHKH*);


UCHKF, UCHKT :		(* peg 07jul79 *)
    begin
    with STK[TOP] do
	begin
	if DTYPE <> TYPUB then ERROR(WCHKF_CHKT_NEEDS_BOOLEAN);
	if IS_CONSTANT(TOP) then
	    begin
	    if (OPC = UCHKF) and (FPA.MEMADR.DSPLMT = 1) then
		ERROR(WBOOL_IS_TRUE)
	    else if (OPC = UCHKT) and (FPA.MEMADR.DSPLMT = 0) then
		ERROR(WBOOL_NOT_TRUE);
	    end (*constant*)
	else
	    begin (*non-constant*)
	    if BREPRES = BJUMP then BJUMP_TO_BINTVAL(TOP);
	    if OPC = UCHKF then
		begin
		LOWBOUND := 0;
		HIGHBOUND := 0;
		end
	    else (*UCHKT*)
		begin
		LOWBOUND := 1;
		HIGHBOUND := 1;
		end;
	    GET_OPERAND(OPND2, TOP);
	    XTNDED_REGDISP_OPERAND(OPND1, S1RPC, 0);
	    UPD_BOUNDTBL(OPND1.XW.DISP, HIGHBOUND, 0, TYPUB);
	    OPND1.FIXUP := BOUNDFIX;
	    EMITXOP(BTRP_N_X[LOWBOUND, TYPUB], OPND1, OPND2);
	    end (*not constant*);
	end;

    FREEDATUMREGS(TOP);
    POPTOP;
    end (*UCHKF, UCHKT*);


UCHKN :			(* peg 07jul79 *)
    begin
    if STK[TOP].DTYPE = TYPUN then
	ERROR(WCHKN_NULL_TOP)
    else if STK[TOP].DTYPE <> TYPUA then
	ERROR(WCHKN_NOT_ADDRESS);
    if IS_CONSTANT(TOP) then
	begin
	if STK[TOP].FPA.MEMADR.DSPLMT < 0 then (*nil*)
	    ERROR(WCHKN_NULL_TOP);
	end (*constant*)
    else
	begin (*not constant*)
	HIGHBOUND := MAXS1ADDR;
	GET_OPERAND(OPND2, TOP);
	XTNDED_REGDISP_OPERAND(OPND1, S1RPC, 0);
	UPD_BOUNDTBL(OPND1.XW.DISP, HIGHBOUND, 0, TYPUA);
	OPND1.FIXUP := BOUNDFIX;
	EMITXOP(BTRP_N_X[0, TYPUA], OPND1, OPND2);
	end (*not constant*);
    end (*UCHKN*);

end (*case OPC of*)
end (*CHECK_OPS*);

(*** ANI_CLASS:	TYPE_CONV_OPS URND UTYP UTYP2 UCVT UCVT2 ***)
(**)


procedure TYPE_CONV_OPS;
begin
case OPC of

URND :		(* peg 21jul79 *)
    begin
    if not ((IS_INTEGER[TYP]) and (IS_REAL[TYPO2])) then
	ERROR(WWRONG_INSTR_DATATYPE);
    if not IS_REAL[STK[TOP].DTYPE] then
	ERROR(WFIX_OF_INVALID_TYPE);
    if TYPO2 <> STK[TOP].DTYPE then ERROR(WINSTR_TYPE_NOT_DATUM_TYPE);

    COERCE_DATUM(TOP, TYP);
    end (*URND*);


UTYP, UTYP2 :		(* als/peg 19jul79 *)
    begin
    if OPC = UTYP then STE := TOP else STE := TOP-1;
    with STK[STE] do
	begin
	if DTYPE <> TYPO2 then ERROR(WINSTR_TYPE_NOT_DATUM_TYPE);
	if TYPO2 in [TYPUB, TYPUC, TYPUI, TYPUJ, TYPUK, TYPUL, TYPUS] then
	    case TYPO2 of
		TYPUB :  NO_ERROR := TYP in [TYPUJ, TYPUL];
		TYPUC :  NO_ERROR := TYP in [TYPUJ, TYPUL];
		TYPUI :  NO_ERROR := TYP in [TYPUK, TYPUS];
		TYPUJ :  NO_ERROR := TYP in [TYPUC, TYPUL, TYPUS];
		TYPUK :  NO_ERROR := TYP in [TYPUJ, TYPUS];
		TYPUL :  NO_ERROR := TYP in [TYPUC, TYPUJ, TYPUS];
		TYPUS :  NO_ERROR := TYP in [TYPUI, TYPUJ, TYPUK, TYPUL];
	    end (*case*)
	else NO_ERROR := false;
	if not NO_ERROR then ERROR(WTYP_WITH_INVALID);

	if TYP = TYPUS then		(*Not implemented until *)
	    ERROR(WNOT_IMPLEMENTED)	(* more than one length of *)
	else if TYPO2 = TYPUS then	(* sets exist. *)
	    ERROR(WNOT_IMPLEMENTED)
        else if (TYPO2 = TYPUB) and (BREPRES=BJUMP) then  (*pn*)
		begin   
		BJUMP_TO_BINTVAL (TOP);
		DTYPE := TYPQ;
		COERCE_DATUM (STE, TYP);
		end
        else if (TYP = TYPUC) then COERCE_DATUM (STE, TYPQ) (*CHR*)
        else if (TYPO2 = TYPUC) then  (*ORD*)
	  begin
          DTYPE := TYPQ;
	  COERCE_DATUM (STE,TYP);
	  end;
	DTYPE := TYP;
	end (*with STK[STE] do*);
    end (*UTYP,UTYP2*);


UCVT, UCVT2 :			(* peg 06jul79 *)

    begin
    if OPC = UCVT then STE := TOP else STE := TOP-1;
    if STK[STE].DTYPE <> TYPO2 then
	ERROR(WINSTR_TYPE_NOT_DATUM_TYPE);

    if TYPO2 in [TYPUI, TYPUJ, TYPUK, TYPUL, TYPUQ, TYPUR] then
	case TYPO2 of
	    TYPUI :  NO_ERROR := TYP in [TYPUC, TYPUJ, TYPUQ, TYPUR];
	    TYPUJ :  NO_ERROR := TYP in [TYPUI, TYPUQ, TYPUR];
	    TYPUK :  NO_ERROR := TYP in [TYPUC, TYPUL, TYPUQ, TYPUR];
	    TYPUL :  NO_ERROR := TYP in [TYPUK, TYPUQ, TYPUR];
	    TYPUQ :  NO_ERROR := TYP in [TYPUI, TYPUJ, TYPUK, TYPUL, TYPUR];
	    TYPUR :  NO_ERROR := TYP in [TYPUI, TYPUJ, TYPUK, TYPUL, TYPUQ];
	end (*case*)
    else NO_ERROR := false;

    if NO_ERROR then
	begin
	if TYPO2 in [TYPUJ, TYPUL] then
	    if IS_REAL[TYP] then
		COERCE_INT_DATUM(STE)
	    else CVT_INT_DATUM(STE);
	COERCE_DATUM(STE, TYP);
	end
    else ERROR(WCVT_WITH_INVALID);
    end (*UCVT, UCVT2*);

end (*case OPC of*)
end (*TYPE_CONV_OPS*);

(*** ANI_CLASS:	VIRT_STK_OPS UDUP USWP UIXA ***)
(**)


procedure VIRT_STK_OPS;
begin
case OPC of

UDUP :			(* als/peg 02jul79 *)
    begin
    if TOP < BOT then ERROR(WDUP_ON_EMPTY_STACK);
    if not (TYP in [TYPUA, TYPUB, TYPUC, TYPUI, TYPUJ,
		    TYPUK, TYPUL, TYPUM, TYPUQ, TYPUR, TYPUS]) then
	ERROR(WWRONG_INSTR_DATATYPE);
    if not( (STK[TOP].DTYPE = TYP) or
            ((TYP = TYPUA) and (STK[TOP].DTYPE = TYPUN)) ) then
	ERROR (WINSTR_TYPE_NOT_DATUM_TYPE);

(*pn 27sep79...*)  if TYP = TYPUS then
			FINDRGBLOCK(S1SETREP_SIZE)
(*...pn 27sep79*)  else if IS_DOUBLE[TYP] then FINDRP else FINDRG;
    OPRRG := NXTRG;
    RESCODESTART := NEWINSTREC;
    REG_OPERAND(OPNDR, OPRRG);
    MOVE_QUANTITY(OPNDR, TOP);
    PUSHTOP;
    REG_DATUM(TOP, RESCODESTART, TYP, OPRRG);
    end(*UDUP*);


USWP :			(* als/peg 02jul79 *)
    begin
    if TOP <= BOT then ERROR(WSWP_NOT_2);
    if not (TYP in [TYPUA, TYPUB, TYPUC, TYPUI, TYPUJ,
		    TYPUK, TYPUL, TYPUM, TYPUQ, TYPUR, TYPUS]) then
	ERROR(WWRONG_INSTR_DATATYPE);
    if not (TYPO2 in [TYPUA, TYPUB, TYPUC, TYPUI, TYPUJ,
		      TYPUK, TYPUL, TYPUM, TYPUQ, TYPUR, TYPUS]) then
	ERROR(WWRONG_INSTR_DATATYPE);
    if ((STK[TOP].DTYPE <> TYP) or (STK[TOP-1].DTYPE <> TYPO2)) then
	ERROR(WSWP_TYP_ERROR);

    BOOL_IN_STK := false;		(* All of this may or may not *)
    for STE := BOT to TOP do		(* accomplish what we want it to, *)
	if STK[STE].DTYPE = TYPUB then	(* which is to prevent codefork *)
	    BOOL_IN_STK := true;	(* side effects.*)
    if BOOL_IN_STK then
	for STE := BOT to TOP do
	    LOADSTKENTRY(STE);		(*Prevent side effects*)
    XCHANGE_STKENTS (TOP, TOP-1);
    end(*USWP*);


UIXA :			(* als/peg 29Jun79 *)
    begin
    if not (STK[TOP-1].DTYPE in [TYPUA, TYPUM]) then
	ERROR(WIXA_NEEDS_ADDR);
    if TYP in [TYPUI, TYPUK] then
	ERROR(WNOT_IMPLEMENTED);
    if I1 mod QWBITS <> 0 then ERROR(WALIGNMENT_ERROR)
    else I1 := I1 div QWBITS;

%*  with STK[TOP] do
	if DTYPE in [TYPUB, TYPUC] then
	    begin
	    if (DTYPE=TYPUB) and (BREPRES=BJUMP) then
		BJUMP_TO_BINTVAL (TOP);
	    DTYPE := TYPQ;
	    end;		*\

    if TYP in [TYPUJ, TYPUL] then
	COERCE_INT_DATUM(TOP);
    (*Multiply top of stack by I1.*)
    with STK[TOP] do
	if I1 <> 1 then
	    begin
	    COMBINABLE := false;
	    CALCULABLE := false;
	    SHIFTDIST := POWER2(I1);
	    RESCODESTART := CODESTART;
	    repeat
		if (SHIFTDIST>=0) and (FPA.MEMADR.LVL=0) and
		   (FINALIND = IND0) and
		   ((NVPAS=0) or
		      ((NVPAS=1) and (VPA1.VSHIFT+SHIFTDIST<=SFLDMAX)))
		  or
		   IS_CONSTANT(TOP)
		then
		    COMBINABLE := true
		else if IS_CNST_PLUS_OPND(TOP) then
		    begin (*index is uncomplicated*)
		    CONSTPART := FPA.MEMADR.DSPLMT * I1;
		    FPA.MEMADR.DSPLMT := 0;
		    IMM_OPERAND (OPND1, I1);
		    FIT_IN_OPERAND (TOOMUCH2, OPND2, TOP);
		    if not (not TOOMUCH2) then ASSERTFAIL('UIXA     001');
		    CALCULABLE := true
		    end (*index is uncomplicated*)
		else
		    begin  (*general case*)
		    FIT_IN_OPERAND (TOOMUCH2, OPND2, TOP);
		    if TOOMUCH2 then
			SIMPLIFY (TOP)
		    else
			begin
			CONSTPART := 0;
			IMM_OPERAND (OPND1, I1);
			CALCULABLE := true;
			end;
		    end (*general case*)
	    until COMBINABLE or CALCULABLE;

	    if CALCULABLE then
		begin
		MULT_SINGLE (DEST, OPND1, OPND2, TOP);
		FREEREGSBUTTHESE (TOP, [DEST]);
		REG_DATUM (TOP, RESCODESTART, TYPUJ, DEST);
		FPA.MEMADR.DSPLMT := CONSTPART;
		end (*CALCULABLE*)

	    else
		begin  (*COMBINABLE*)
		FPA.MEMADR.DSPLMT := FPA.MEMADR.DSPLMT * I1;
		if not ((NVPAS<=1) or (I1=1)) then ASSERTFAIL('UIXA     002');
		if NVPAS = 1 then
		    VPA1.VSHIFT := VPA1.VSHIFT + SHIFTDIST;
		CODESTART := RESCODESTART
		end (*COMBINABLE*);

	    end (*with STK[TOP] do*);


    (*Simplify datums until combinable.  We cannot emit an add
	to combine them since the result must be
	an address, with its high order bits zero.*)

    if IS_CONSTANT(TOP) and
	   (STK[TOP].FPA.MEMADR.DSPLMT = 0) then
	(*index is zero so just discard it*)
    else
	begin  (*non-zero index*)
	while STK[TOP].FINALIND > IND0 do
	    SIMPLIFY (TOP);
	while STK[TOP-1].FINALIND > IND0 do
	    SIMPLIFY (TOP-1);
	if STK[TOP-1].NVPAS > 0 then
	    while STK[TOP].NVPAS > 1 do
		SIMPLIFY (TOP);
	if STK[TOP].NVPAS > 0 then
	    while STK[TOP-1].NVPAS > 1 do
		SIMPLIFY (TOP-1);

	if not ((STK[TOP].FINALIND = IND0) and
		(STK[TOP-1].FINALIND = IND0) and
		(STK[TOP].FPA.MEMADR.LVL = 0) and
		(STK[TOP].NVPAS + STK[TOP-1].NVPAS <= 2) ) then
            ASSERTFAIL('UIXA     003');

	STK[TOP-1].FPA.MEMADR.DSPLMT :=
	    STK[TOP-1].FPA.MEMADR.DSPLMT + STK[TOP].FPA.MEMADR.DSPLMT;
	if STK[TOP-1].NVPAS = 0 then
	    case STK[TOP].NVPAS of
		0 : (*null case*);
		1 : STK[TOP-1].VPA1 := STK[TOP].VPA1;
		2 : begin
		    STK[TOP-1].VPA1 := STK[TOP].VPA1;
		    STK[TOP-1].VPA2 := STK[TOP].VPA2;
		    end
	    end (*case*)
	else if STK[TOP-1].NVPAS = 1 then
	    begin
	    if STK[TOP].NVPAS = 1 then
		STK[TOP-1].VPA2 := STK[TOP].VPA1
	    end;

	STK[TOP-1].NVPAS :=
	     STK[TOP-1].NVPAS + STK[TOP].NVPAS;
	end (*non-zero index*);

    if RTBUSER = TOP then RTBUSER := TOP - 1;
    POPTOP;
    end (*UIXA*);

end (*case OPC of*)
end (*VIRT_STK_OPS*);

(*** ANI_CLASS:	PROC_CALL_OPS UMST UPAR UCUP UICUP UCSP URET ***)
(**)


procedure PROC_CALL_OPS;
begin
case OPC of

UMST :			(* als/peg 17jul79 *)
    begin
    if MSTTOP >= MAXMST then
	ERROR (WFUNC_CALLS_NESTED_TOO_DEEPLY)
    else
	begin
	SP_EXCESS := 0;		(*SETPARMKLUDGE*)
	MSTTOP := MSTTOP + 1;
	with MSTSTK[MSTTOP] do
	    begin
	    DESTLEV := I1;
	    MSTCODESTART := NEWINSTREC;
	    if MSTTOP = 1 then
		CURPARMREGS := CURRENT_PARMREG_COUNT
	    else CURPARMREGS := MIN(MAXPAREG, PWORDCOUNT);
	    end (*with MSTSTK[MSTTOP]*);

	if (MSTTOP = 1) and (MSTSTK[MSTTOP].CURPARMREGS > 0) then
	    SAVE_PARMREGS;

	PWORDCOUNT := 0;
	if CURLVL = 1 then
	    OFFSET := FILE_OFFSET
	else (*CURLVL > 1*)
	    OFFSET := R_OFFSET;
	DSPL := MSTSTK[MSTTOP-1].EVALSAVESTART;
	for STE := BOT to TOP do	(*Save expression stack*)
	    with STK[STE] do
		if NVPAS > 0 then
		    if (DTYPE = TYPUB) and (BREPRES = BJUMP) then
			begin (*Save BJUMP temp reg just in case used*)
			DSPL := DSPL + WORDUNITS;
			REGDISP_OPERAND(OPND1, DISPLAY, OFFSET - DSPL);
			REG_OPERAND(OPNDR, VPA1.VPA.RGADR);
			EMITXOP(XMOV_S_S, OPND1, OPNDR)
			end (*Save BJUMP temp reg*)
		    else
			begin
			(*This datum's value may be susceptible to
			    change by side effect.  Get it into eval
			    save area to protect it.*)
			if IS_DOUBLE[DTYPE] then
			    DSPL := DSPL + DOUBLEWORDUNITS
			else DSPL := DSPL + WORDUNITS;
			REGDISP_OPERAND(OPND1, DISPLAY, OFFSET - DSPL);
			MOVE_QUANTITY (OPND1, STE);
(**** Note: check for *)if not DAT_IS_T_REG(STE)
(* non-reg. expr. temp*)   and not DAT_IS_FILADR(STE) then
			    begin  (*arrange to restore it to a temp*)
			    if IS_DOUBLE[DTYPE] then FINDRP
						else FINDRG;
			    REG_DATUM (STE, CODESTART, DTYPE, NXTRG);
			    end;
			end (*get datum into eval save*);
	FREE_TEMP_REGS;
	RESERVE_PARMREGS(0);
	MSTSTK[MSTTOP].EVALSAVESTART := DSPL;
	if DSPL > EVALSAVE.SIZE then EVALSAVE.SIZE := DSPL;

	PUSH_STKFRAME;
	end (*no error*);

    end (*UMST*);


UPAR :

    begin
    IF STK[TOP].DTYPE = TYPUM then  (*pn*)
        COERCE_DATUM (TOP, TYPUA);
    if not( (STK[TOP].DTYPE = TYP) or
            ((TYP = TYPUA) and (STK[TOP].DTYPE = TYPUN)) ) then
	ERROR(WINSTR_TYPE_NOT_DATUM_TYPE);

    if STK[TOP].DTYPE = TYPUB then
	begin						(*SETPARMKLUDGE...*)
	if STK[TOP].BREPRES = BJUMP then
	    BJUMP_TO_BINTVAL(TOP);
	end

    else if STK[TOP].DTYPE = TYPUS then
	(*Large value parameters are passed by passing their address and
	  copying into the callee's local area.  This applies to sets of
	  greater than two-word length (e.g., four-word sets).  At present,
	  PCPASC (and therefore PTRANS) produces code to pass sets directly
	  in the caller and to copy them in the callee; therefore, SOPU
	  must coerce set parameters to TYPUA.  This is accomplished by
	  allocating some space on top of the runtime stack, moving the
	  actual set there and adjusting the stack pointer appropriately,
	  and putting the new address of the set in a register (which will
	  probably be the correct parmreg).  This problem should go away
	  soon when UPAS becomes fully operational -- peg 23sep79.*)

	begin
	FINDRG;  OPRRG := NXTRG;
	REG_OPERAND(OPNDR, OPRRG);
	EMITXOP(XMOV_S_S, OPNDR, OPNDRSP);
	ALLOC_EXCESS(S1SETREP_SIZE);		(*must be deallocated in CUP*)
	SP_EXCESS := SP_EXCESS + S1SETREP_SIZE;
	REGDISP_OPERAND(OPND1, OPRRG, 0);
	GET_OPERAND(OPND2, TOP);
	EMITXOP(MOV_X_X[TYPUS], OPND1, OPND2);
	FREEREGSBUTTHESE(TOP, [OPRRG]);
	REG_DATUM(TOP, STK[TOP].CODESTART, TYPUA, OPRRG);
	end (*if STK[TOP].DTYPE = TYPUS*);		(*...SETPARMKLUDGE*)

    if not ((PWORDCOUNT >= MAXPAREG)
      or ((PWORDCOUNT = MAXPAREG) and (IS_DOUBLE[TYP]))) then
	begin (*reg. parm*)
	PREG := MINPARS1REG + PWORDCOUNT;
	CORRECT := false;
	LOADSTKENTRY(TOP);          (*This may get it into the correct reg.*)
	if DAT_IS_REG(TOP) then
	    if STK[TOP].VPA1.VPA.RGADR = PREG then
		CORRECT := true;

	if not CORRECT then (*move parameter to correct reg.*)
	    with MSTSTK[MSTTOP] do
		begin
		if not RISFREE[PREG] then ASSERTFAIL('UPAR     001');
		if IS_DOUBLE[TYP] then
		    begin
		    if not RISFREE[succ(PREG)] then ASSERTFAIL('UPAR     002');
		    ALLOCRP(PREG);
		    S1OP := MOVMS_N[2];
		    end
		else
		    begin
		    ALLOCRG(PREG);
		    S1OP := XMOV_S_S;
		    end;

		GET_OPERAND(OPND2, TOP);
		RESCODESTART := STK[TOP].CODESTART;
		REG_OPERAND(OPND1, PREG);
		EMITXOP(S1OP, OPND1, OPND2);
		FREEDATUMREGS(TOP);
		REG_DATUM(TOP, RESCODESTART, TYP, PREG);
		end (*move parameter*);
	end (*reg. parm*);

    if IS_DOUBLE[TYP] then
	PWORDCOUNT := PWORDCOUNT + 2
    else
	PWORDCOUNT := PWORDCOUNT + 1;
    end (*UPAR*);


UCUP, UICUP: 			(*peg 09aug79*)
    begin
    if OPC = UICUP then PRMTOP := TOP-1
    else PRMTOP := TOP;

    if (PRMTOP - BOT) + 1 < I2 then
	ERROR(W2_MANY_PARMS_SPECIFIED)
    else if (PRMTOP - BOT) + 1 > I2 then
	ERROR(WINSUFF_PARMS_SPECIFIED);

    if not ((IS_INTEGER[TYP]) or (IS_REAL[TYP])
      or (TYP in [TYPUA, TYPUB, TYPUC, TYPUP])) then
	ERROR(WILLEGAL_PROC_TYPECODE);

    if ((TYP = TYPUP) and (I3 <> 0))
      or ((IS_INTEGER[TYP] or IS_REAL[TYP]
	   or (TYP in [TYPUA, TYPUB, TYPUC])) and (I3 <> 1)) then
	ERROR(WWRONG_RESULT_NUMBER);

    PARM := BOT;
    LASTREGPARM := PARM;
    PWORDCOUNT := 0;
    EXCESS := 0;
    while PARM <= PRMTOP do
	begin (*check reg. parms for correct order, collect excess*)
	if (PWORDCOUNT >= MAXPAREG)
	  or ((PWORDCOUNT = MAXPAREG) and (IS_DOUBLE[TYP])) then
	    if IS_DOUBLE[STK[PARM].DTYPE] then
		EXCESS := EXCESS + 2			(*peg 24sep79*)
	    else EXCESS := EXCESS + 1			(*peg 24sep79*)
	else
	    begin (*reg. parm*)
	    LASTREGPARM := PARM;
	    PREG := MINPARS1REG + PWORDCOUNT;
	    if not (DAT_IS_REG(PARM)
	      and (STK[PARM].VPA1.VPA.RGADR = PREG)) then
		ASSERTFAIL('UCUP     001');
	    end (*reg. parm*);

	if IS_DOUBLE[STK[PARM].DTYPE] then
	    PWORDCOUNT := PWORDCOUNT + 2
	else PWORDCOUNT := PWORDCOUNT + 1;
	PARM := PARM + 1;
	end (*check reg. parms*);

    MINTMPS1REG := PREG + 1;
    MAXTMPS1REG := MAX(MAXTMPS1REG,MINTMPS1REG-1);
    CHECK_DSP_TMP_COLLISION;

    if EXCESS > 0 then	(* move excess parms to stack top, *)
	begin		(* pass address of overflow area in RTB *)
	if not RISFREE[S1RTB] then MOVE_AND_FREE_RTB;
	ALLOCRG(S1RTB);
	EMITXOP(XMOV_S_S, OPNDRTB, OPNDRSP);
	ALLOC_EXCESS(EXCESS);			(*peg 23sep79*)
	DSPL := -EXCESS*WORDUNITS;		(*peg 24sep79*)
	for PARM := LASTREGPARM + 1 to PRMTOP do
	    begin
	    REGDISP_OPERAND(OPND1, S1RSP, DSPL);
	    MOVE_QUANTITY(OPND1, PARM);
	    if IS_DOUBLE[STK[PARM].DTYPE] then
		DSPL := DSPL + DOUBLEWORDUNITS
	    else DSPL := DSPL + WORDUNITS;
	    end;
	end (*move excess parms*);

    if OPC = UCUP then
        begin
	REG_OPERAND(OPNDR, LVL_TO_S1REG[MSTSTK[MSTTOP].DESTLEV]);
	EXT_REGADDR_OPERAND(OPND2, S1RPC, SEG_EP_RELPC);       (*EJG*)
	OPND2.FIXUP := XTRNSYMFIX;
	UPD_PROCTBL(OPND2.FIXPTR, NAM1.NAM);
	EMITJOP(XJSR, 0, OPNDR, OPND2, nil);
        end
    else
        begin
        (* put the address of the beginning of PSWITCH into a spare register *)
        (* the problem with this is that XTRNSYMFIX doesn't work with
           an XMOV instead of an XJSR *)
	FINDRG; OPRRG := NXTRG;
	REG_OPERAND (OPNDR,OPRRG);
	EXT_REGADDR_OPERAND(OPND2, S1RPC, SEG_EP_RELPC);
	OPND2.FIXUP := XTRNSYMFIX; 
	UPD_PROCTBL(OPND2.FIXPTR, PSWITCHNAME);
	EMITXOP(XMOV_S_S, OPNDR, OPND2);

        (* now use the procedure number as index *)
	COERCE_DATUM (TOP, TYPUJ);
	if IS_CONSTANT(TOP) then ERROR (WNOT_IMPLEMENTED);
	GET_SHORT_OPERAND (OPND, TOP);
	OPND2 := OPND;
	OPND2.X := 1;
	OPND2.XW.V := 1;
	OPND2.XW.S := DALIGNSHIFT;
	OPND2.XW.REG := OPRRG;
	OPND2.XW.DISP := 0;
	REG_OPERAND(OPNDR, LVL_TO_S1REG[4]);
	JUMPINDEXED := NEWINSTREC;
	EMITJOP(XJSR, 0, OPNDR, OPND2, nil);
	ADD_INSTPTR_TO_OPND2FIXLIST (NEG_SHIFT_FIXLIST, JUMPINDEXED);  
	FREEDATUMREGS(TOP);
	POPTOP;
	FREERG_S(OPRRG);
        end;

    if EXCESS > 0 then	(*restore SP*)
	begin
	FREERG_S(S1RTB);		(*peg 23sep79*)
	DEALLOC_EXCESS(EXCESS);		(*peg 23sep79*)
	end (*restore SP*);

    if SP_EXCESS > 0 then	(*SETPARMKLUDGE...*)
	begin
	DEALLOC_EXCESS(SP_EXCESS);
	SP_EXCESS := 0;
	end;			(*...SETPARMKLUDGE*)

    while TOP >= BOT do		(*free parm regs. ...*)
	with STK[TOP] do
	    begin
	    if DAT_IS_REG(TOP) then FREERG_S(VPA1.VPA.RGADR)
	    else FREEDATUMREGS(TOP);
	    POPTOP;
	    end;			(*... free parm regs.*)

    FREE_TEMP_REGS;
    if MSTTOP > 1 then
	begin
	PWORDCOUNT := MSTSTK[MSTTOP].CURPARMREGS;
	RESERVE_PARMREGS(0);
	end
    else
	RESERVE_PARMREGS(MSTSTK[MSTTOP].CURPARMREGS);

    POP_STKFRAME;
    with MSTSTK[MSTTOP-1], CURPROCSPEC do
	begin  (*Restore expr stack and parmregs.*)
	RTBSAVED := false;
	if CURLVL = 1 then
	    OFFSET := FILE_OFFSET
	else (*CURLVL > 1*)
	    OFFSET := R_OFFSET;
	DSPL := EVALSAVESTART;
	for STE := BOT to TOP do
	    with STK[STE] do
	    if NVPAS > 0 then
		if (DTYPE = TYPUB) and (BREPRES = BJUMP) then
		    begin (*Restore BJUMP temp reg*)
		    REG_OPERAND(OPNDR, VPA1.VPA.RGADR);
		    DSPL := DSPL + WORDUNITS;
		    ALLOCRG(VPA1.VPA.RGADR);
		    REGDISP_OPERAND(OPND2, DISPLAY, OFFSET - DSPL);
		    EMITXOP(XMOV_S_S,OPNDR,OPND2)
		    end (*Restore BJUMP temp reg*)
		else
		    begin  (*Restore one expr temp.*)
		    if not (DAT_IS_T_REG(STE) or DAT_IS_FILADR(STE) ) then
                        ASSERTFAIL('UCUP     002');
		    FIT_IN_OPERAND (TOOMUCH1, OPND1, STE);
		    if TOOMUCH1 then ASSERTFAIL('UCUP     003');
		    if IS_DOUBLE[DTYPE] then DSPL := DSPL + DOUBLEWORDUNITS
					else DSPL := DSPL + WORDUNITS;
		    if (TYP<>TYPUP) and IS_RTB(OPND1) then
			begin
			(*We will be getting a function value back in
			    RTB, so remember to restore the thing
			    which was there into another temporary,
			    after restoring all the others so we know
			    which ones are available.*)
			RTBSAVED := true;
			RTBDATUM := STE;
			RTBDSPL := DSPL;
			end  (*RTB*)
		    else
			begin  (*ordinary temporary*)
			if DAT_IS_T_REG(STE) then
			    if IS_DOUBLE[DTYPE] then
				ALLOCRP(VPA1.VPA.RGADR)
			    else ALLOCRG(VPA1.VPA.RGADR);
			REGDISP_OPERAND(OPND2, DISPLAY, OFFSET - DSPL);
			EMITXOP (MOV_X_X[DTYPE], OPND1, OPND2);
			end (*ordinary temp reg*);
		    end (*restore one expr temp*);

	if RTBSAVED then
	    with STK[RTBDATUM] do
		begin  (*Restore it somewhere else*)
		if IS_DOUBLE[DTYPE] then
		    begin  FINDRP;  S1OP := XMOV_D_D;  end
		else
		    begin  FINDRG;  S1OP := XMOV_S_S;  end;
		VPA1.VPA.RGADR := NXTRG;
		REG_OPERAND (OPNDR, NXTRG);
		REGDISP_OPERAND(OPND2, DISPLAY, OFFSET - RTBDSPL);
		EMITXOP (S1OP, OPNDR, OPND2);
		end (*if RTBSAVED*);

	if MSTTOP = 1 then RESTORE_PARMREGS;
	end  (*Restore expr stack and parmregs.*);

    if TYP <> TYPUP then
	begin  (*Function value being returned in RTB.*)
	PUSHTOP;
	if IS_DOUBLE[TYP] then ALLOCRP (S1RTB) else ALLOCRG (S1RTB);
	REG_DATUM (TOP, MSTSTK[MSTTOP].MSTCODESTART, TYP, S1RTB);
	RTBUSER := TOP;
	RTBDOUB := IS_DOUBLE[TYP];
	end (*function value being returned*);

    MSTTOP := MSTTOP - 1;

    end (*UCUP*);



UCSP : CALLSTANDARD;


URET :				(* als/peg 29Jun79 *)
    with CURPROCSPEC do
	begin
	REG_OPERAND (OPNDR, DISPLAY);
	if DEBUG then
	    begin
	    if CURLVL = 1 then
		XTNDED_REGDISP_OPERAND (OPND2, DISPLAY,
					  -WORDUNITS - L1DISPLAY_OFFSET
					  (*- Eval save size by fixup*) )
	    else (*CURLVL > 1*)
		XTNDED_REGDISP_OPERAND (OPND2, DISPLAY,
					  -WORDUNITS - DISPLAY_OFFSET
					  (*- Eval save size by fixup*) );
	    ADDR_OPERAND (OPND1, S1GSEGBASE*WORDUNITS);
	    INSTLOC := NEWINSTREC;
	    EMITXOP (XMOV_S_S, OPND1, OPND2);
	    ADD_INSTPTR_TO_OPND2FIXLIST (EVALSAVE.NEGFIXLIST, INSTLOC);	(*DATASTRCH*)

	    if CURLVL = 1 then
		XTNDED_REGDISP_OPERAND (OPND2, DISPLAY,
			      		-WORDUNITS - L1DISPLAY_OFFSET
(*LCW)                                    (*- Eval save size by fixup*) )
	    else (*CURLVL > 1*)
		XTNDED_REGDISP_OPERAND (OPND2, DISPLAY,
			        	-WORDUNITS - DISPLAY_OFFSET
(*LCW*)					  (*- Eval save size by fixup*) );
            end
	else
	    if CURLVL = 1 then
		XTNDED_REGDISP_OPERAND (OPND2, DISPLAY, -L1DISPLAY_OFFSET
(*LCW*)					  (*- Eval save size by fixup*) )
	    else (*CURLVL > 1*)
		XTNDED_REGDISP_OPERAND (OPND2, DISPLAY, -DISPLAY_OFFSET
(*LCW*)					  (*- Eval save size by fixup*) );
	INSTLOC := NEWINSTREC;
	EMITXOP (XRETSR, OPNDR, OPND2);
	ADD_INSTPTR_TO_OPND2FIXLIST (EVALSAVE.NEGFIXLIST, INSTLOC);	(*DATASTRCH*)

	end (*URET*);

end (*case OPC of*)
end (*PROC_CALL_OPS*);

(*** ANI_CLASS:	IMP_EXP_OPS UIMPP UIMPV UEXPP UEXPV ***)
(**)


procedure IMP_EXP_OPS;
begin
case OPC of

UIMPP :
    begin
    ERROR (WNOT_IMPLEMENTED);
    end (*UIMPP*);


UIMPV :
    begin
    ERROR (WNOT_IMPLEMENTED);
    end (*UIMPV*);


UEXPP :
    begin
    ERROR (WNOT_IMPLEMENTED);
    end (*UEXPP*);


UEXPV :
    begin
    ERROR (WNOT_IMPLEMENTED);
    end (*UEXPV*);

end (*case OPC of*)
end (*IMP_EXP_OPS*);

(*** ANI_CLASS:	COMP_TIME_OPS UCOMM UOPTN ULEX USYM ULIVE UDEAD UDOA UDEF UMDEF ULOC ***)
(**)


procedure COMP_TIME_OPS;
begin
case OPC of

UCOMM :			(* als/peg 29Jun79 *)
    begin
    (* COMM is currently a no-op. *)
    end (*UCOMM*);


UOPTN :			(*only enough letters used to disambiguate*)
    begin
    if NAM1.NAM[1] = 'T' then
	begin
	NO_ERROR := true;
	if      NAM1.NAM[2] = 'A' then ASM   := I1 = 1
	else if NAM1.NAM[2] = 'D' then DEBUG := I1 = 1
	else if NAM1.NAM[2] = 'M' then
	    begin
	    if      I1 = 0 then TR_MST := false
	    else if I1 = 1 then TR_MST := true
	    else if I1 < 0 then
	        PRINT_MSTENTRY (-I1)
	    else NO_ERROR := false;
	    end
%*	else if NAM1.NAM[2] = 'N' then	(* commented out -- peg 18jul79 *)
	    begin
	    if I1 = 0 then TR_NEST := false 
	    else if I1 = 1 then TR_NEST := true
	    else PRINT_NESTITEM (I1)
	    end				*\(*end comment out *)
	else if NAM1.NAM[2] = 'P' then
	    begin
	    if      NAM1.NAM[6] = 'H' then
		if      I2 = 1 then NO_JMPX_TO_JMPA_FLG := I1 = 0
		else if I2 = 2 then NO_SKIP_JMPA_FLG    := I1 = 0
		else if I2 = 3 then NO_COLLAPSE_MOV_FLG := I1 = 0
		else if I2 = 4 then NO_INC_SKP_FLG      := I1 = 0
		else NO_ERROR := false
	    else if NAM1.NAM[6] = 'O' then
		begin
		NO_JMPX_TO_JMPA_FLG := I1 = 0;
		NO_SKIP_JMPA_FLG    := I1 = 0;
		NO_COLLAPSE_MOV_FLG := I1 = 0;
		NO_INC_SKP_FLG      := I1 = 0;
		end
	    else if NAM1.NAM[6] = 'T' then TR_PEEPHOLE := I1 = 1
	    else NO_ERROR := false;
	    end
	else if NAM1.NAM[2] = 'S' then 
	    begin
	    if NAM1.NAM[3] = '1' then
		if      I1 = 0 then TR_S1CODE := false
		else if I1 = 1 then TR_S1CODE := true
		else if I1 = -1 then
		    begin
		    IPTR := MAINCODE.FIRST;
		    S1PC := SEG_EP_RELPC;
		    while IPTR <> nil do
			begin
			DISASSEMBLE (S1PC, IPTR);
			IPTR := IPTR↑.NEXTPTR;			(*DATASTRCH*)
			end;
		    end
		else NO_ERROR := false

	    else if NAM1.NAM[3] = 'I' then
		if      I1 = 0 then TR_SIMP := false
		else if I1 = 1 then TR_SIMP := true
		else if I1 < 0 then SIMPLIFY (-I1)
		else NO_ERROR := false

	    else if NAM1.NAM[3] = 'T' then
		if      I1 = 0 then TR_STACK := false
		else if I1 = 1 then TR_STACK := true
		else if I1 < 0 then PRINTDATUM (-I1)
		else NO_ERROR := false

	    else NO_ERROR := false;
	    end

	else if NAM1.NAM[2] = 'U' then TR_UCODE := I1 = 1
	else NO_ERROR := false;

	if (not NO_ERROR) and TR_UCODE then 
	    writeln(OUTPUT,'*** WARNING: Invalid or unrecognized OPTN ***');
	end;
    end (*UOPTN*);


ULEX :		(* als/peg 09jul79 *)
    begin
    if (I2 < MINBLOCK) or (I2 > MAXBLOCK) then
	ERROR(WINVAL_BLOCK_NUMBER);
    BLOCKTABLE[I2] := I1;
    end (*ULEX*);


USYM :		(* als/peg 09jul79 *)
    begin
    (* NOTE: this instruction will remain unimplemented until some specifications
	for a symbolic debugger and the information it needs (and where it will go,
	etc.) have been created -- als/peg.*)
    (* SYM is currently a no-op. *)
    end (*USYM*);


ULIVE :		(* als/peg 09jul79 *)
    begin
    (* LIVE is currently a no-op. *)
    end (*ULIVE*);


UDEAD :		(* als/peg 09jul79 *)
    begin
    (* DEAD is currently a no-op. *)
    end (*UDEAD*);


UDOA :		(* als/peg 09jul79 *)
    begin
    (* DOA is currently a no-op. *)
    end (*UDOA*);


UDEF :		(* als/peg 13jul79 *)
    begin
    if I1 mod WORDBITS <> 0 then
	ERROR(WALIGNMENT_ERROR);
    with CURPROCSPEC do
	if MTYP = R_SPACE then
	    R_MEMORY_AREA := REGIMAGEAREASIZE*QWBITS
	else if MTYP = M_SPACE then
	    begin
	    M_MEMORY_AREA := I1;
	    STACKFRAME.SIZE := STACKFRAME.SIZE + (I1 div QWBITS);
	    end
	else ERROR (WNOT_IMPLEMENTED);
    end (*UDEF*);


UMDEF :
    begin
    (* NOTE: See Universal P-Code Definition, version [0.2] for details on
	this instruction.  A minimum implementation, allowing consistency checks
	between this instruction and memory usage, should be easily implementable,
	but requires some new data structures and routines; these should be care-
	fully thought out -- peg.*)
    end (*UMDEF*);


ULOC :			(**** als should fix this.*)
(*	LOC  <line number> <page number> <stmt count> <basblock?>
where:
	<line number> and <page number> refer to the original PASCAL source file.
	<stmt count> is the number of the statement in that line
	<basblock?>  is one if this is the first statement of a basic block,
			zero otherwise.*)
    begin
    CURPLOC := I1;
    (*A 'LOC 0' precedes each procedure, at which time the code list
	has not yet been initialized.  Hence do not emit a ULOC fake
	instruction in that case.*)(**** Is this still true??*)
    if I1 > 0 then
	begin
	if DEBUG then EMITFAKEOP (XPLOC, I1);
	end;
    end (*ULOC*);

end (*case OPC of*)
end (*COMP_TIME_OPS*);

(*** ANI_CLASS:		***)
(**)
(*** ANI ==> ASSEMBLE_NEXT_INSTRUCTION ***)


begin (*ASMNXTINST*)
if JUMPTABLE_IN_PROGRESS then
    JUMPTABLE_IN_PROGRESS :=
	(OPC=UUJP) or (OPC=ULAB) or (OPC=UDEF) or (OPC=ULOC)
	    or (OPC=UBGN)
else
    JUMPTABLE_IN_PROGRESS := false;

(*Some operations are available as both instructions and
    as standard procedures.  Translate such into either one or the
    other to avoid duplication of effort.*)
(* Requires PASCAL-UCode compilers to emit CSP NEW/DSP!!!*)
%
if (OPC = UNEW) or (OPC = UDSP) then
    begin
    NAM1.LEN := 3;
    if OPC = UDSP then
	begin
	NAM1.NAM := 'DSP     '
	end (*if OPC = UDSP*)
    else if OPC = UNEW then
	begin
	NAM1.NAM := 'NEW     ';
	PUSHTOP;
	STK[TOP] := ZERODATUM;
	with STK[TOP] do
	    begin
	    CODESTART := NEWINSTREC;
	    DTYPE := TYPUJ;
	    FPA.MEMADR.DSPLMT := I1;
	    end;
	OPC := UCSP;
	end (*if OPC = UNEW*)
    end (*if (OPC = ...*); \


case OPC of

    UABS, UNEG, UADD, UINC, UDEC :	ARITH_1_OPS;
    USUB :				ARITH_2_OPS;
    UMPY, USQR :			ARITH_3_OPS;
    UDIV, UDMD, UMOD :			ARITH_4_OPS;
    
    UEQU, UGEQ, UGRT, ULEQ, ULES,
    UNEQ, UIEQU,UIGEQ,UIGRT,UILEQ,
    UILES,UINEQ :			REL_OPS;

    UAND, UIOR, UXOR, UNOT, UODD :	BOOL_OPS;

    UDIF, UINT, UUNI, UINN, USGS,
    UADJ, UMUS :			SET_OPS;

    ULCA, ULDA, ULDC, ULOD, ULDP,UILOD,
    UPLOD :				LOAD1_STORE_OPS;

    USTR,UNSTR,UISTR,UINST,UPSTR, UMOV :
					LOAD2_STORE_OPS;

    UFJP, UTJP, UUJP, UXJP,UGOOB,
    ULAB,UCLAB :			FLOW_CONTROL_OPS;

    UBGN, UEND, USTP, UENT,UBGNB,
    UENDB :				ENVIRONMENT_OPS;

    UCHKL,UCHKH,UCHKT,UCHKF,UCHKN :	CHECK_OPS;

    URND, UTYP, UTYP2, UCVT,UCVT2 :	TYPE_CONV_OPS;

    UDUP, USWP, UIXA :			VIRT_STK_OPS;

    UMST, UPAR, UCUP,UICUP, UCSP,
    URET :				PROC_CALL_OPS;

    UIMPP,UIMPV,UEXPP,UEXPV :		IMP_EXP_OPS;

    UCOMM,UOPTN, ULEX, USYM,ULIVE,
    UDEAD, UDOA, UDEF,UMDEF, ULOC :	COMP_TIME_OPS;

    UNEW, UDSP :			ERROR(WNOT_IMPLEMENTED);
    

    end (*case OPC of*);

end (*ASMNXTINST*);

(** READNXTINST_CLASS:	READNXTINST READNAM READTYP READMTYP READINT READREAL READSTRING READSET UUNK *)
(**)

procedure READNXTINST;
    (*Read next P-Code instruction and convert it to internal form.*)

    var CH :  char;

    procedure READNAM (var NAM : NAMEREC);
	(*Skip initial blanks and commas and read a
	    label or procedure identifier into NAM.*)
	var I :  0..ALFASIZE;
	    CH :  char;
	begin
	while (INPUT↑=' ') or (INPUT↑=',') do
	    get (INPUT);
	NAM.NAM := '                ';
	I := 0;
	repeat
	    I := I + 1;
	    READ (INPUT, CH);
	    NAM.NAM[I] := CH
	until (I=ALFASIZE) or (INPUT↑=' ') or (INPUT↑=',');
	while (INPUT↑<>' ') and (INPUT↑<>',') do
	    get (INPUT);
	NAM.LEN := I;
	end (*READNAM*);

    procedure READTYP (var TYP :  OPNDTYPE);
	(*Skip initial blanks and commas and read a
	    type character. Translate it into an
	    OPNDTYPE and return it in TYP.*)
	var CH :  char;
	begin
	repeat
	    READ (INPUT, CH)
	until (CH <> ' ') and (CH <> ',');
	TYP := FIRSTTYPE;
	while (TYP < LASTTYPE) and (TYPECODE[TYP] <> CH) do
	    TYP := succ(TYP);
	if TYPECODE[TYP] <> CH then
	    ERROR (WINVAL_U_TYPECODE);
	end (*READTYP*);

    procedure READMTYP (var TYP :  MEMTYPE);
	(*Skip initial blanks and commas and read a
	    type character. Translate it into a
	    MEMTYPE and return it in TYP.*)

	var CH :  char;
	begin
	repeat
	    READ (INPUT, CH)
	until (CH <> ' ') and (CH <> ',');
	TYP := FIRSTMTYPE;
	while (TYP < LASTMTYPE) and (MTYPECODE[TYP] <> CH) do
	    TYP := succ(TYP);
	if MTYPECODE[TYP] <> CH then
	    ERROR (WINVALID_MEMORY_TYPE);
	end (*READTYP*);

    procedure READINT (var I :  integer);
	(*Skip initial blanks and commas and read an
	    integer into I.*)
	begin
	while (INPUT↑=' ') or (INPUT↑=',') do
	    get (INPUT);
	READ (INPUT, I);;
	end (*READINT*);

    procedure READREAL (var R :  real);
	(*Skip initial blanks and commas and read a
	    real number into R.*)
	begin
	while (INPUT↑=' ') or (INPUT↑=',') do
	    get (INPUT);
	READ (INPUT, R);;
	end (*READREAL*);

(* Comment out the 370 version...
    procedure READSET(var S :  SETREP);
	%*Read an input-format set and convert it to a SETREP,
	    returning it in S.	This procedure changes when
	    sets get bigger for the real machine.*\
	var SETINT :
	    record
		DUMMY :  integer;  %*alignment (not needed?)*\
		case BIT of
		    0 :  (S :  SETREP);
		    1 :  (I :  array[1..2] of integer)
		end %*SETINT*\;
	    INT1, INT2 :  integer;

	begin
	while INPUT↑ <> '(' do get(INPUT);
	get(INPUT);
	READINT(INT1);
	READINT(INT2);
	SETINT.I[1] := INT1*TWOEXP[16] + INT2;
	READINT(INT1);
	READINT(INT2);
	SETINT.I[2] := INT1*TWOEXP[16] + INT2;
	S := SETINT.S
	end %*READSET*\;
...*)


    procedure READSET(var S :  SETREP);
	(*Read a set as a string of octal digits and convert it to a SETREP,
	    returning it in S.  PDP-10 version. *)
        (* pn 19SEP79 *)

	var J, N :  integer;
	    CH : char;

	begin
	while (INPUT↑=' ') do get (INPUT);
	S := NULL_SET;					
	N := 0;
	while N < SET_SIZE do 
          begin
          read (INPUT, CH);
          J := ORD (CH) - ORD ('0');
          if J > 3 then BUILD_SET(S,N);
          if (J mod 4) > 1 then BUILD_SET(S,N+1);
          if odd(J) then BUILD_SET(S,N+2);
  	  N := N + 3;
 	  end
	end (*READSET*);
    
    procedure READSTRING(var STRVAL :  STRINGTYPE; var STRLGTH :  STRINX);
	(*Read a string into STRVAL -- als/peg 24jul7.*)

	var CH :  char;

	begin
	WHILE (CH <> '''') and not eoln (INPUT) do READ (CH);
	READ (CH);
	STRLGTH := 0;
	while (CH<>'''') or (INPUT↑='''') do
	    begin
	    STRLGTH := STRLGTH + 1;
	    SVAL[STRLGTH] := CH;
	    if CH = '''' then READ (CH);
	    READ (CH);
	    end (*while*);
	end (*READSTRING*);
    

    begin (*READNXTINST*)
    if INPUT↑ <> ' ' then READNAM (NAM0);
    repeat  get(INPUT)	until INPUT↑ <> ' ';
    READ(CH); MNEM[1] := CH;
    READ(CH); MNEM[2] := CH;
    READ(CH); MNEM[3] := CH;
    if INPUT↑ = ' ' then CH := ' ' else READ(CH);
    MNEM[4] := CH;
    OPC := MNEM_TO_OPC(MNEM);

    case OPC of

	UCHKF, UCHKN, UCHKT, URET :
		(*null case*);

	UCLAB, ULAB, UMST, UNEW, UPLEX  :
		READINT (I1);

        UGOOB, UEXPP, UIMPP, UIMPV :
		begin
		READINT (I1);
		READNAM (NAM1);
		end;
		
	ULEX :  begin
		READINT (I1);
		READINT (I2);
		end;

	ULDP :	begin
		READINT (I1);
		READINT (I2);
		READNAM (NAM1);
		end;
		
	ULOC :  begin
		READINT (I1);
		READINT (I2);
		READINT (I3);
		READINT (I4);
		end;



	UEND :	READNAM (NAM1);

	UBGN, UFJP, UUJP, USTP , UTJP: 
		READNAM (NAM1);

	UOPTN :	begin
		READNAM (NAM1);
		READINT (I1);
		if (NAM1.NAM[1] = 'P') and (NAM1.NAM[6] = 'H') then
		    READINT (I2);
		end;

	UABS, UADD, USUB, UMPY, UDIV, UAND, UDIF, UDMD, UDSP, UDUP, 
	UEQU, UNEQ, UGEQ, UGRT, ULEQ, ULES, UIEQU,UINEQ,UIGEQ,UIGRT,
	UILEQ,UILES,UINN, UINT, UIOR, UMOD, UMUS, UNEG, UNOT, UODD, 
	USDEF,USGS, USQR, UUNI :
		READTYP (TYP);

	UCVT, UCVT2, URND, USWP, UTYP, UTYP2 :
		begin
		READTYP (TYP);
		READTYP (TYPO2);
		end;

	UDEC, UINC, UIXA, UMOV :
		begin
		READTYP (TYP);
		READINT (I1);
		end;

	UCHKL, UCHKH :
		begin
		READTYP (TYP);
		READINT (I1);
		end;

	UADJ, UILOD, UINST, UISTR:
		begin
		READTYP (TYP);
		READINT (I1);
		READINT (I2);
		end;


        UENT :	begin
		READTYP (TYP);
		READINT (I1);
		READINT (I2);
		READINT (I3);
		READINT (I4);
		end;


	UDEF :  begin
		READMTYP (MTYP);
		READINT (I1);
		end;


	UDEAD, UDOA, UEXPV, ULDA, ULIVE :
		begin
		READMTYP (MTYP);
		READINT (I1);
		READINT (I2);
		READINT (I3);
		end;

	UMDEF :	begin
		READMTYP (MTYP);
		READINT (I1);
		READINT (I2);
		READINT (I3);
		while (CH = ' ') and not eoln(INPUT) do READ(CH);
		SLGTH := 0;
		while (SLGTH < STRINGMAX) and not eoln(INPUT) do
		    begin
		    READ (CH);
		    SLGTH := SLGTH + 1;
		    SVAL[SLGTH] := CH;
		    end (*while*);
		end;

	UXJP :
		begin
		READTYP (TYP);
		READNAM (NAM1);
		READNAM (NAM2);
		READINT (I1);
		READINT (I2);
		end;

	ULOD, UNSTR, UPAR, UPLOD, UPSTR, USTR, USYM :
		begin
		READTYP (TYP);
		READMTYP (MTYP);
		READINT (I1);
		READINT (I2);
		READINT (I3);
		end;

	UCSP :	begin
		READTYP (TYP);
		READNAM (NAM1);
		READINT (I1);
		READINT (I2);
		end;

	UCUP, UICUP :	
		begin
		READTYP (TYP);
		if OPC = UCUP then
		    begin
		    READINT (I1);
		    READNAM (NAM1);
		    end;
		READINT (I2);
		READINT (I3);
		end;

	ULDC :	begin
		READTYP (TYP);
		READINT (I1);
		case TYP of
		    TYPUI, TYPUK, TYPUM, TYPUQ :
			     ERROR(WNOT_IMPLEMENTED);
		    TYPUB, TYPUJ, TYPUL :
			     READINT (I2);
		    TYPUC :  READSTRING (SVAL, SLGTH);
		    TYPUR :  READREAL (R1);
		    TYPUN :  (*null case*);
		    TYPUS :  READSET (P1);
		    end (*case TYP of*);
		end (*ULDC*);

	ULCA :	begin
		READTYP (TYP);
		READINT (I1);
		case TYP of
		    TYPUI, TYPUK, TYPUQ :
			     ERROR(WNOT_IMPLEMENTED);
		    TYPUB, TYPUJ, TYPUL :
			     READINT (I2);
		    TYPUC :  READSTRING (SVAL, SLGTH);
		    TYPUR :  READREAL (R1);
		    TYPUS :  READSET (P1);
		    TYPUM :  READSTRING (SVAL, SLGTH);
		    end (*case TYP of*);
		end (*ULCA*);

	UCOMM :
		begin   (* pn *)
		while (CH = ' ') and not eoln(INPUT) do READ(CH);
		CLEN := 0;
		while not eoln(INPUT) and (CLEN < COMMLEN) do
		    begin
		    CLEN := CLEN + 1;
		    READ(CH); COMMFIELD[CLEN] := CH;
		    end;
		end (*UCOMM*);


	UUNK :	begin
		READINT (I2);
		READINT (I3);
		while (CH = ' ') and not eoln(INPUT) do READ(CH);
		(* READSTRING (SVAL, SLGTH); *)
		end;

    end (*case OPC of*);

    READLN(INPUT);

    end (*READNXTINST*);

(** INITIALIZE_CLASS:	INITIALIZE ENTER_OPC ENTER_CSP INIT1 **)
(**)

procedure INITIALIZE;

    var
	I, N :	integer;
	T, T1, T2 :  OPNDTYPE;
	S1OP :	S1OPCODE;

    procedure ENTER_OPC (NAM :	CHAR4;	OPC :  U_OPCODE);		(*ALS*)
	var H : 0..OPCHTSIZEM1;
	begin
	H := OPC_HASH(NAM);
	while OPCHASHTAB[H].OPCNAM <> '    ' do
	    H := (H + 1) mod OPCHTSIZE;
	OPCHASHTAB[H].OPCNAM := NAM;
	OPCHASHTAB[H].OPC := OPC;
	end (*ENTER_OPC*);

    procedure ENTER_CSP (NAM :	CHAR3;	CSP :  P_STANDARDPROC);
	var H : 0..CSPHTSIZEM1;
	    NAMALFA :  ALFA;
	begin
	NAMALFA := '                ';
	NAMALFA[1]:=NAM[1]; NAMALFA[2]:=NAM[2]; NAMALFA[3]:=NAM[3];
	H := CSP_HASH(NAMALFA);
	while CSPHASHTAB[H].CSPNAM.NAM <> '                ' do
	    H := (H + 1) mod CSPHTSIZE;
	CSPHASHTAB[H].CSPNAM.NAM := NAMALFA;
	CSPHASHTAB[H].CSPNAM.LEN := 3;
	CSPHASHTAB[H].CSP := CSP;
	end (*ENTER_CSP*);


    procedure INIT1;
	begin
(*%IFF SET4*)
	for I := 0 to SETREP_MAX DO         
	  NULL_SET[I] := [ ];               
(*%ELSE*)
%	NULL_SET := [ ];  \
(*%ENDC*)

        for I := MINBLOCK to MAXBLOCK do
	  BLOCKTABLE[I] := ILLBLOCKNO;

	ZEROS1WORD.LHALF := 0;       ZEROS1WORD.RHALF := 0;

	with EMPTY_OP do
	    begin
	    X := 0;
	    REG := 0;                F := 0;
	    FIXUP := NOFIX;          FIXPTR := nil;
	    XW.FMT := XW_EV;         XW.P := 0;
	    XW.V := 0;               XW.D := 0;
	    XW.I := 0;               XW.S := 0;
	    XW.ADDR := 0;            XW.REG := 0;
	    XW.DISP := 0;
	    end (*EMPTY_OP*);

	with ZERO_OP do
	    begin
	    X := 0;
	    REG := 1;                F := 0;
	    FIXUP := NOFIX;  FIXPTR := nil;
	    XW.FMT := XW_C;  XW.VAL := ZEROS1WORD;
	    end (*ZERO_OP*);

	with EXTENDED_ZERO_OP do
	    begin
	    X := 1;
	    REG := 1;                F := 1;
	    FIXUP := NOFIX;  FIXPTR := nil;
	    XW.FMT := XW_C;  XW.VAL := ZEROS1WORD;
	    end (*EXTENDED_ZERO_OP*);

	with EMPTYCODELIST do
	    begin
	    NWORDS := 0;
	    FIRST := nil;            LAST := nil;
	    end (*EMPTYCODELIST*);

	with EMPTYOPND2FIXLIST do                                   (*DATASTRCH*)
	    begin
	    NWORDS := 0;
	    FIRST := nil;            LAST := nil;
	    end (*EMPTYOPND2FIXLIST*);


	with EMPTYOPNDXWORDFIXLIST do                               (*DATASTRCH*)
	    begin
	    NWORDS := 0;
	    FIRST := nil;
	    LAST := nil;
	    end(*EMPTYOPNDXWORDFIXLIST*);

	with EMPTYINSTLIST do                                       (*DATASTRCH*)
	    begin
	    NWORDS := 0;
	    FIRST := nil;
	    LAST := nil;
	    end(*EMPTYINSTLIST*);

	with EMPTYJUMPLIST do
	    begin
	    NWORDS := 0;
	    FIRST := nil;            LAST := nil;
	    end (*EMPTYJUMPLIST*);

	with ZEROFPA do
	    begin
	    WHICH := MEM;
	    MEMADR.LVL := 0;         MEMADR.DSPLMT := 0;
	    end (*ZEROFPA*);

	with ZEROVPA do
	    begin
	    VSHIFT := 0;             VPAIND := IND1;
	    VPA.WHICH := MEM;
	    VPA.MEMADR.LVL := 0;
	    VPA.MEMADR.DSPLMT := 0;
	    end (*ZEROVPA*);

	with ZERODATUM do
	    begin
	    CODESTART := nil;
	    DTYPE := TYPUP;  (*no legal datum should be*)
	    DLENGTH := 0;
	    MTYPE := NON_SPACE;
	    BREPRES := BINTVAL;
	    BTRUELIST := EMPTYJUMPLIST;
	    BFALSELIST := EMPTYJUMPLIST;
	    BFALLTHRUSKIPLOC := nil;
	    BJUMPON := false;
	    SCNST := NULL_SET;       RCNST := 0.0;          (*setch*)
	    FINALIND := IND0;        FPA := ZEROFPA;
	    NVPAS := 0;
	    VPA1 := ZEROVPA; VPA2 := ZEROVPA;
	    end (*ZERODATUM*);

    with CURPROCSPEC do				(* peg 18jul79...*)
	begin  (*Set up dummy entry*)
	PROCTYPE := TYPUP;
	PROCNAM.NAM := 'DUMMY	        ';
	PROCNAM.LEN := 5;
	REGPARMAREA := 0;
	R_MEMORY_AREA := MIN_ON_COMP_MACH;
	M_MEMORY_AREA := MIN_ON_COMP_MACH;
	end (*CURPROCSPEC*);			(*...peg 18jul79 *)

	REG_OPERAND (UNUSED_OP, S1R0);      (*unused operands must specify R0*)
	REG_OPERAND (OPNDRTB, S1RTB);
	REG_OPERAND (OPNDRSP, S1RSP);

	SEG_EP_RELPC := SEG_START_RELPC + SEG_EP_DISP;

	FIRSTTYPE := ILLARITH;       LASTTYPE := TYPUS;
	FIRSTMTYPE := NON_SPACE;     LASTMTYPE := M_SPACE;
	DEFAULTMTYPE := M_SPACE;
	FIRSTS1OP := XILLEGAL;       LASTS1OP := XXOR_Q;
	FIRSTSKIP := XDSKP_EQL;      LASTSKIP := XSKP_ANY_D;	(*28JUN79 PTZ*)

	TWOEXP[0] := 1;
	for I := 1 to MAX_EXP_ON_COMP_MACH do  TWOEXP[I] := 2 * TWOEXP[I-1];

	MAXTMPS1REG := MINPARS1REG - 1;
	MINDSPS1REG := MAXDSPS1REG + 1;

	JUMPTABLE_IN_PROGRESS := false;

	MTYPECODE[NON_SPACE] := ' ';
	MTYPECODE[R_SPACE] := 'R';
	MTYPECODE[M_SPACE] := 'M';

	TYPECODE[TYPUA] := 'A';		(*address*)
	TYPECODE[TYPUB] := 'B';		(*boolean*)
	TYPECODE[TYPUC] := 'C';		(*character*)
	TYPECODE[TYPUE] := 'E';		(*entry point of proc. as parameter*)
	TYPECODE[TYPUI] := 'I';		(*double-word integer*)
	TYPECODE[TYPUJ] := 'J';		(*single-word integer*)
	TYPECODE[TYPUK] := 'K';		(*double-word non-neg. integer*)
	TYPECODE[TYPUL] := 'L';		(*single-word non-neg. integer*)
	TYPECODE[TYPUM] := 'M';		(*record, array*)
	TYPECODE[TYPUN] := 'N';		(*nil pointer*)
	TYPECODE[TYPUP] := 'P';		(*procedure*)
	TYPECODE[TYPUQ] := 'Q';		(*double-word real*)
	TYPECODE[TYPUR] := 'R';		(*single-word real*)
	TYPECODE[TYPUS] := 'S';		(*set*)

	ALIGNBNDRY[TYPUA] := WORDUNITS;
	ALIGNBNDRY[TYPUB] := QUARTERWORDUNITS;
	ALIGNBNDRY[TYPUC] := QUARTERWORDUNITS;
	ALIGNBNDRY[TYPUE] := WORDUNITS;
	ALIGNBNDRY[TYPUI] := WORDUNITS;
	ALIGNBNDRY[TYPUJ] := WORDUNITS;
	ALIGNBNDRY[TYPUK] := WORDUNITS;
	ALIGNBNDRY[TYPUL] := WORDUNITS;
	ALIGNBNDRY[TYPUM] := WORDUNITS;
	ALIGNBNDRY[TYPUN] := WORDUNITS;
	ALIGNBNDRY[TYPUP] := 0;
	ALIGNBNDRY[TYPUQ] := WORDUNITS;
	ALIGNBNDRY[TYPUR] := WORDUNITS;
	ALIGNBNDRY[TYPUS] := WORDUNITS;
	ALIGNBNDRY[TYPH] := HALFWORDUNITS;
	ALIGNBNDRY[TYPQ] := QUARTERWORDUNITS;

	S1SIZE[TYPUA] := S1S;             S1SIZE[TYPUM] := S1S;
	S1SIZE[TYPUB] := S1Q;             S1SIZE[TYPUN] := S1S;
	S1SIZE[TYPUC] := S1Q;             S1SIZE[TYPUP] := S1S;
	S1SIZE[TYPUI] := S1D;             S1SIZE[TYPQ]  := S1Q;
	S1SIZE[TYPH]  := S1H;             S1SIZE[TYPUR] := S1S;
	S1SIZE[TYPUJ] := S1S;             S1SIZE[TYPUS] := S1D;
	S1SIZE[TYPUQ] := S1D;

	FUNCUNITS[TYPUA] := WORDUNITS;
	FUNCUNITS[TYPUB] := WORDUNITS;
	FUNCUNITS[TYPUC] := WORDUNITS;
	FUNCUNITS[TYPUI] := DOUBLEWORDUNITS;
	FUNCUNITS[TYPUJ] := WORDUNITS;
	FUNCUNITS[TYPUK] := DOUBLEWORDUNITS;
	FUNCUNITS[TYPUL] := WORDUNITS;
	FUNCUNITS[TYPUM] := WORDUNITS;
	FUNCUNITS[TYPUN] := WORDUNITS;
	FUNCUNITS[TYPUP] := 0;
	FUNCUNITS[TYPUQ] := DOUBLEWORDUNITS;
	FUNCUNITS[TYPUR] := WORDUNITS;
	FUNCUNITS[TYPUS] := 0;			(*setch*)
	FUNCUNITS[TYPH]  := WORDUNITS;
	FUNCUNITS[TYPQ]  := WORDUNITS;

	for T := FIRSTTYPE to LASTTYPE do
	    begin
(*peg==>*)  IS_DOUBLE[T] := (T in [TYPUI, TYPUK, TYPUQ %, TYPUS\]);(*setch*)
(*27sep79*) IS_SINGLE[T] := (T in [TYPUA, TYPUJ, TYPUL, TYPUM, TYPUN, TYPUR]);
	    IS_INTEGER[T] := (T in [TYPQ, TYPH, TYPUI, TYPUJ, TYPUK, TYPUL]);
	    IS_REAL[T] := (T in [TYPUQ, TYPUR]);
	    IS_SIGNED_NUM[T] := (T in [TYPUI, TYPUJ, TYPUQ, TYPUR]);
	    end (*for T*);

	SKP_NON_X[TYPUA] := XILLEGAL;         SKP_NON_X[TYPUM] := XILLEGAL;
	SKP_NON_X[TYPUB] := XSKP_NON_Q;       SKP_NON_X[TYPUN] := XILLEGAL;
	SKP_NON_X[TYPUC] := XSKP_NON_Q;       SKP_NON_X[TYPUP] := XILLEGAL;
	SKP_NON_X[TYPUI] := XSKP_NON_D;       SKP_NON_X[TYPQ]  := XSKP_NON_Q;
	SKP_NON_X[TYPUK] := XSKP_NON_D;
	SKP_NON_X[TYPH]  := XSKP_NON_H;       SKP_NON_X[TYPUR] := XILLEGAL;
	SKP_NON_X[TYPUJ] := XSKP_NON_S;       SKP_NON_X[TYPUS] := XILLEGAL;
	SKP_NON_X[TYPUL] := XSKP_NON_S;
	SKP_NON_X[TYPUQ] := XILLEGAL;

	MOVMQ_N[1]  := XMOV_Q_Q;             MOVMQ_N[2]  := XMOVMQ_2;
	MOVMQ_N[3]  := XMOVMQ_3;             MOVMQ_N[4]  := XMOVMQ_4;
	MOVMQ_N[5]  := XMOVMQ_5;             MOVMQ_N[6]  := XMOVMQ_6;
	MOVMQ_N[7]  := XMOVMQ_7;             MOVMQ_N[8]  := XMOVMQ_8;
	MOVMQ_N[9]  := XMOVMQ_9;             MOVMQ_N[10] := XMOVMQ_10;
	MOVMQ_N[11] := XMOVMQ_11;            MOVMQ_N[12] := XMOVMQ_12;
	MOVMQ_N[13] := XMOVMQ_13;            MOVMQ_N[14] := XMOVMQ_14;
	MOVMQ_N[15] := XMOVMQ_15;            MOVMQ_N[16] := XMOVMQ_16;
	MOVMQ_N[17] := XMOVMQ_17;            MOVMQ_N[18] := XMOVMQ_18;
	MOVMQ_N[19] := XMOVMQ_19;            MOVMQ_N[20] := XMOVMQ_20;
	MOVMQ_N[21] := XMOVMQ_21;            MOVMQ_N[22] := XMOVMQ_22;
	MOVMQ_N[23] := XMOVMQ_23;            MOVMQ_N[24] := XMOVMQ_24;
	MOVMQ_N[25] := XMOVMQ_25;            MOVMQ_N[26] := XMOVMQ_26;
	MOVMQ_N[27] := XMOVMQ_27;            MOVMQ_N[28] := XMOVMQ_28;
	MOVMQ_N[29] := XMOVMQ_29;            MOVMQ_N[30] := XMOVMQ_30;
	MOVMQ_N[31] := XMOVMQ_31;            MOVMQ_N[32] := XMOVMQ_32;

	MOVMS_N[1]  := XMOV_S_S;             MOVMS_N[2]  := XMOVMS_2;  (*ALS*)
	MOVMS_N[3]  := XMOVMS_3;             MOVMS_N[4]  := XMOVMS_4;
	MOVMS_N[5]  := XMOVMS_5;             MOVMS_N[6]  := XMOVMS_6;
	MOVMS_N[7]  := XMOVMS_7;             MOVMS_N[8]  := XMOVMS_8;
	MOVMS_N[9]  := XMOVMS_9;             MOVMS_N[10] := XMOVMS_10;
	MOVMS_N[11] := XMOVMS_11;            MOVMS_N[12] := XMOVMS_12;
	MOVMS_N[13] := XMOVMS_13;            MOVMS_N[14] := XMOVMS_14;
	MOVMS_N[15] := XMOVMS_15;            MOVMS_N[16] := XMOVMS_16;
	MOVMS_N[17] := XMOVMS_17;            MOVMS_N[18] := XMOVMS_18;
	MOVMS_N[19] := XMOVMS_19;            MOVMS_N[20] := XMOVMS_20;
	MOVMS_N[21] := XMOVMS_21;            MOVMS_N[22] := XMOVMS_22;
	MOVMS_N[23] := XMOVMS_23;            MOVMS_N[24] := XMOVMS_24;
	MOVMS_N[25] := XMOVMS_25;            MOVMS_N[26] := XMOVMS_26;
	MOVMS_N[27] := XMOVMS_27;            MOVMS_N[28] := XMOVMS_28;
	MOVMS_N[29] := XMOVMS_29;            MOVMS_N[30] := XMOVMS_30;
	MOVMS_N[31] := XMOVMS_31;            MOVMS_N[32] := XMOVMS_32;  (*ALS*)

	MOV_X_X[TYPUA] := XMOV_S_S;           MOV_X_X[TYPUM] := XMOV_S_S;
	MOV_X_X[TYPUB] := XMOV_Q_Q;           MOV_X_X[TYPUN] := XMOV_S_S;
	MOV_X_X[TYPUC] := XMOV_Q_Q;           MOV_X_X[TYPUP] := XILLEGAL;
	MOV_X_X[TYPUI] := XMOV_D_D;           MOV_X_X[TYPQ]  := XMOV_Q_Q;
	MOV_X_X[TYPUK] := XMOV_D_D;
	MOV_X_X[TYPH]  := XMOV_H_H;           MOV_X_X[TYPUR] := XMOV_S_S;
	MOV_X_X[TYPUJ] := XMOV_S_S;           
	MOV_X_X[TYPUL] := XMOV_S_S;           
	MOV_X_X[TYPUS] := MOVMS_N[NUMOFSETPARTS*2];	(*setch*)
	MOV_X_X[TYPUQ] := XMOV_D_D;

	ABS_X[TYPUA] := XILLEGAL;             ABS_X[TYPUM] := XILLEGAL;
	ABS_X[TYPUB] := XILLEGAL;             ABS_X[TYPUN] := XILLEGAL;
	ABS_X[TYPUC] := XILLEGAL;             ABS_X[TYPUP] := XILLEGAL;
	ABS_X[TYPUI] := XABS_D;               ABS_X[TYPQ]  := XABS_Q;
	ABS_X[TYPUK] := XABS_D;
	ABS_X[TYPH]  := XABS_H;               ABS_X[TYPUR] := XABS_S;
	ABS_X[TYPUJ] := XABS_S;               ABS_X[TYPUS] := XILLEGAL;
	ABS_X[TYPUL] := XABS_S;
	ABS_X[TYPUQ] := XABS_D;

	NEG_X[TYPUA] := XILLEGAL;             NEG_X[TYPUM] := XILLEGAL;
	NEG_X[TYPUB] := XILLEGAL;             NEG_X[TYPUN] := XILLEGAL;
	NEG_X[TYPUC] := XILLEGAL;             NEG_X[TYPUP] := XILLEGAL;
	NEG_X[TYPUI] := XNEG_D;               NEG_X[TYPQ]  := XNEG_Q;
	NEG_X[TYPUK] := XNEG_D; 
	NEG_X[TYPH]  := XNEG_H;               NEG_X[TYPUR] := XNEG_S;
	NEG_X[TYPUJ] := XNEG_S;               NEG_X[TYPUS] := XILLEGAL;
	NEG_X[TYPUL] := XNEG_S;
	NEG_X[TYPUQ] := XNEG_D;

	FLOAT_S_X[TYPUA] := XILLEGAL;
	FLOAT_S_X[TYPUB] := XILLEGAL;
	FLOAT_S_X[TYPUC] := XILLEGAL;
	FLOAT_S_X[TYPUI] := XFLOAT_S_D;
	FLOAT_S_X[TYPUK] := XFLOAT_S_D;
	FLOAT_S_X[TYPH]  := XFLOAT_S_H;
	FLOAT_S_X[TYPUJ] := XFLOAT_S_S;
	FLOAT_S_X[TYPUL] := XFLOAT_S_S;
	FLOAT_S_X[TYPUM] := XILLEGAL;
	FLOAT_S_X[TYPUN] := XILLEGAL;
	FLOAT_S_X[TYPUP] := XILLEGAL;
	FLOAT_S_X[TYPQ]  := XFLOAT_S_Q;
	FLOAT_S_X[TYPUR] := XILLEGAL;
	FLOAT_S_X[TYPUS] := XILLEGAL;
	FLOAT_S_X[TYPUQ] := XILLEGAL;

	SLR_N[0] := XSLR_0;                 SLR_N[1] := XSLR_1;
	SLR_N[2] := XSLR_2;                 SLR_N[3] := XSLR_3;
	SLR_N[4] := XSLR_4;                 SLR_N[5] := XSLR_5;
	SLR_N[6] := XSLR_6;                 SLR_N[7] := XSLR_7;
	SLR_N[8] := XSLR_8;                 SLR_N[9] := XSLR_9;
	SLR_N[10] := XSLR_10;               SLR_N[11] := XSLR_11;
	SLR_N[12] := XSLR_12;               SLR_N[13] := XSLR_13;
	SLR_N[14] := XSLR_14;               SLR_N[15] := XSLR_15;
	SLR_N[16] := XSLR_16;               SLR_N[17] := XSLR_17;
	SLR_N[18] := XSLR_18;               SLR_N[19] := XSLR_19;
	SLR_N[20] := XSLR_20;               SLR_N[21] := XSLR_21;
	SLR_N[22] := XSLR_22;               SLR_N[23] := XSLR_23;
	SLR_N[24] := XSLR_24;               SLR_N[25] := XSLR_25;
	SLR_N[26] := XSLR_26;               SLR_N[27] := XSLR_27;
	SLR_N[28] := XSLR_28;               SLR_N[29] := XSLR_29;
	SLR_N[30] := XSLR_30;               SLR_N[31] := XSLR_31;

	SLRADR_N[0] := XSLRADR_0;           SLRADR_N[1] := XSLRADR_1;
	SLRADR_N[2] := XSLRADR_2;           SLRADR_N[3] := XSLRADR_3;
	SLRADR_N[4] := XSLRADR_4;           SLRADR_N[5] := XSLRADR_5;
	SLRADR_N[6] := XSLRADR_6;           SLRADR_N[7] := XSLRADR_7;
	SLRADR_N[8] := XSLRADR_8;           SLRADR_N[9] := XSLRADR_9;
	SLRADR_N[10] := XSLRADR_10;         SLRADR_N[11] := XSLRADR_11;
	SLRADR_N[12] := XSLRADR_12;         SLRADR_N[13] := XSLRADR_13;
	SLRADR_N[14] := XSLRADR_14;         SLRADR_N[15] := XSLRADR_15;
	SLRADR_N[16] := XSLRADR_16;         SLRADR_N[17] := XSLRADR_17;
	SLRADR_N[18] := XSLRADR_18;         SLRADR_N[19] := XSLRADR_19;
	SLRADR_N[20] := XSLRADR_20;         SLRADR_N[21] := XSLRADR_21;
	SLRADR_N[22] := XSLRADR_22;         SLRADR_N[23] := XSLRADR_23;
	SLRADR_N[24] := XSLRADR_24;         SLRADR_N[25] := XSLRADR_25;
	SLRADR_N[26] := XSLRADR_26;         SLRADR_N[27] := XSLRADR_27;
	SLRADR_N[28] := XSLRADR_28;         SLRADR_N[29] := XSLRADR_29;
	SLRADR_N[30] := XSLRADR_30;         SLRADR_N[31] := XSLRADR_31;

	BTRP_B_X[TYPUA] := XBTRP_B_S;         BTRP_B_X[TYPUM] := XBTRP_B_S;
	BTRP_B_X[TYPUB] := XBTRP_B_Q;         BTRP_B_X[TYPUN] := XILLEGAL;
	BTRP_B_X[TYPUC] := XBTRP_B_Q;         BTRP_B_X[TYPUP] := XILLEGAL;
	BTRP_B_X[TYPUI] := XBTRP_B_D;         BTRP_B_X[TYPQ]  := XBTRP_B_Q;
	BTRP_B_X[TYPUK] := XBTRP_B_D; 
	BTRP_B_X[TYPH]  := XBTRP_B_H;         BTRP_B_X[TYPUR] := XILLEGAL;
	BTRP_B_X[TYPUJ] := XBTRP_B_S;         BTRP_B_X[TYPUS] := XILLEGAL;
	BTRP_B_X[TYPUL] := XBTRP_B_S;
	BTRP_B_X[TYPUQ] := XILLEGAL;

	BTRP_N_X[0,TYPUA] := XBTRP_0_S;
	BTRP_N_X[0,TYPUB] := XBTRP_0_Q;
	BTRP_N_X[0,TYPUC] := XBTRP_0_Q;
	BTRP_N_X[0,TYPUI] := XBTRP_0_D;
	BTRP_N_X[0,TYPUK] := XBTRP_0_D;
	BTRP_N_X[0,TYPH]  := XBTRP_0_H;
	BTRP_N_X[0,TYPUJ] := XBTRP_0_S;
	BTRP_N_X[0,TYPUL] := XBTRP_0_S;
	BTRP_N_X[0,TYPUM] := XBTRP_0_S;
	BTRP_N_X[0,TYPUN] := XILLEGAL;
	BTRP_N_X[0,TYPUP] := XILLEGAL;
	BTRP_N_X[0,TYPQ]  := XBTRP_0_Q;
	BTRP_N_X[0,TYPUR] := XILLEGAL;
	BTRP_N_X[0,TYPUS] := XILLEGAL;
	BTRP_N_X[0,TYPUQ] := XILLEGAL;

	BTRP_N_X[1,TYPUA] := XBTRP_1_S;
	BTRP_N_X[1,TYPUB] := XBTRP_1_Q;
	BTRP_N_X[1,TYPUC] := XBTRP_1_Q;
	BTRP_N_X[1,TYPUI] := XBTRP_1_D;
	BTRP_N_X[1,TYPUK] := XBTRP_1_D;
	BTRP_N_X[1,TYPH]  := XBTRP_1_H;
	BTRP_N_X[1,TYPUJ] := XBTRP_1_S;
	BTRP_N_X[1,TYPUL] := XBTRP_1_S;
	BTRP_N_X[1,TYPUM] := XBTRP_1_S;
	BTRP_N_X[1,TYPUN] := XILLEGAL;
	BTRP_N_X[1,TYPUP] := XILLEGAL;
	BTRP_N_X[1,TYPQ]  := XBTRP_1_Q;
	BTRP_N_X[1,TYPUR] := XILLEGAL;
	BTRP_N_X[1,TYPUS] := XILLEGAL;
	BTRP_N_X[1,TYPUQ] := XILLEGAL;


	end (*INIT1*);

(** INITIALIZE_CLASS:			INIT2 **)
(**)

    procedure INIT2;
    begin
    for T1 := FIRSTTYPE to LASTTYPE do
	for T2 := FIRSTTYPE to LASTTYPE do
	    begin
	    MOV_X_Y[T1, T2] := XILLEGAL;
	    ARITH_RESULT_TYPE[T1, T2] := ILLARITH;
	    COMPARE_COERCE_TYPE[T1, T2] := ILLCOMP;
	    end (*for*);

    MOV_X_Y [TYPUA, TYPUA] := XMOV_S_S;
    MOV_X_Y [TYPUA, TYPUN] := XMOV_S_S;
    MOV_X_Y [TYPUA, TYPUM] := XMOV_S_S;
    MOV_X_Y [TYPUB, TYPUB] := XMOV_Q_Q;
    MOV_X_Y [TYPUC, TYPUC] := XMOV_Q_Q;
    MOV_X_Y [TYPQ, TYPQ]   := XMOV_Q_Q;
    MOV_X_Y [TYPQ, TYPH]   := XTRANS_Q_H;
    MOV_X_Y [TYPQ, TYPUI]  := XTRANS_Q_D;
    MOV_X_Y [TYPQ, TYPUJ]  := XTRANS_Q_S;
    MOV_X_Y [TYPQ, TYPUK]  := XTRANS_Q_D;
    MOV_X_Y [TYPQ, TYPUL]  := XTRANS_Q_S;
    MOV_X_Y [TYPH, TYPQ]   := XTRANS_H_Q;
    MOV_X_Y [TYPH, TYPH]   := XMOV_H_H;
    MOV_X_Y [TYPH, TYPUI]  := XTRANS_H_D;
    MOV_X_Y [TYPH, TYPUJ]  := XTRANS_H_S;
    MOV_X_Y [TYPH, TYPUK]  := XTRANS_H_D;
    MOV_X_Y [TYPH, TYPUL]  := XTRANS_H_S;
    MOV_X_Y [TYPUI, TYPQ]  := XTRANS_D_Q;
    MOV_X_Y [TYPUI, TYPH]  := XTRANS_D_H;
    MOV_X_Y [TYPUI, TYPUI] := XMOV_D_D;
    MOV_X_Y [TYPUI, TYPUJ] := XTRANS_D_S;
    MOV_X_Y [TYPUI, TYPUK] := XMOV_D_D;
    MOV_X_Y [TYPUI, TYPUL] := XTRANS_D_S;
    MOV_X_Y [TYPUJ, TYPQ]  := XTRANS_S_Q;
    MOV_X_Y [TYPUJ, TYPH]  := XTRANS_S_H;
    MOV_X_Y [TYPUJ, TYPUI] := XTRANS_S_D;
    MOV_X_Y [TYPUJ, TYPUJ] := XMOV_S_S;
    MOV_X_Y [TYPUJ, TYPUK] := XTRANS_S_D;
    MOV_X_Y [TYPUJ, TYPUL] := XMOV_S_S;
    MOV_X_Y [TYPUJ, TYPUR] := XFX_DM_S_S;
    MOV_X_Y [TYPUK, TYPQ]  := XTRANS_D_Q;
    MOV_X_Y [TYPUK, TYPH]  := XTRANS_D_H;
    MOV_X_Y [TYPUK, TYPUI] := XMOV_D_D;
    MOV_X_Y [TYPUK, TYPUJ] := XTRANS_D_S;
    MOV_X_Y [TYPUK, TYPUK] := XMOV_D_D;
    MOV_X_Y [TYPUK, TYPUL] := XTRANS_D_S;
    MOV_X_Y [TYPUL, TYPQ]  := XTRANS_S_Q;
    MOV_X_Y [TYPUL, TYPH]  := XTRANS_S_H;
    MOV_X_Y [TYPUL, TYPUI] := XTRANS_S_D;
    MOV_X_Y [TYPUL, TYPUJ] := XMOV_S_S;
    MOV_X_Y [TYPUL, TYPUK] := XTRANS_S_D;
    MOV_X_Y [TYPUL, TYPUL] := XMOV_S_S;
    MOV_X_Y [TYPUL, TYPUR] := XFX_DM_S_S;
    MOV_X_Y [TYPUQ, TYPUQ] := XMOV_D_D;
    MOV_X_Y [TYPUQ, TYPUR] := XFTRANS_D_S;
    MOV_X_Y [TYPUR, TYPUI] := XFLOAT_S_D;
    MOV_X_Y [TYPUR, TYPUJ] := XFLOAT_S_S;
    MOV_X_Y [TYPUR, TYPUK] := XFLOAT_S_D;
    MOV_X_Y [TYPUR, TYPUL] := XFLOAT_S_S;
    MOV_X_Y [TYPUR, TYPUQ] := XFTRANS_S_D;
    MOV_X_Y [TYPUR, TYPUR] := XMOV_S_S;
    MOV_X_Y [TYPUS, TYPUS] := MOVMS_N[NUMOFSETPARTS*2];	(*setch*)

    for T1 := TYPQ to TYPUJ do
	for T2 := TYPQ to TYPUJ do
	    ARITH_RESULT_TYPE[T1,T2] := TYPUJ;
    for T := TYPQ to TYPUI do
	begin
	ARITH_RESULT_TYPE[T,TYPUI] := TYPUI;
	ARITH_RESULT_TYPE[TYPUI,T] := TYPUI;
	end;
    ARITH_RESULT_TYPE [TYPUQ,TYPUQ] := TYPUQ;
    ARITH_RESULT_TYPE [TYPUQ,TYPUR] := TYPUQ;
    ARITH_RESULT_TYPE [TYPUR,TYPUQ] := TYPUQ;
    ARITH_RESULT_TYPE [TYPUR,TYPUR] := TYPUR;

    COMPARE_COERCE_TYPE [TYPUA,TYPUM] := TYPUA;
    COMPARE_COERCE_TYPE [TYPUM,TYPUA] := TYPUA;
    COMPARE_COERCE_TYPE [TYPUA,TYPUN] := TYPUA;
    COMPARE_COERCE_TYPE [TYPUN,TYPUA] := TYPUA;
    COMPARE_COERCE_TYPE [TYPUA,TYPUA] := TYPUA;
    COMPARE_COERCE_TYPE [TYPUQ,TYPUQ] := TYPUQ;
    COMPARE_COERCE_TYPE [TYPUR,TYPUQ] := TYPUQ;
    COMPARE_COERCE_TYPE [TYPUQ,TYPUR] := TYPUQ;
    COMPARE_COERCE_TYPE [TYPUR,TYPUR] := TYPUR;
    COMPARE_COERCE_TYPE [TYPQ,TYPQ] := TYPQ;
    COMPARE_COERCE_TYPE [TYPQ,TYPH] := TYPH;
    COMPARE_COERCE_TYPE [TYPH,TYPQ] := TYPH;
    COMPARE_COERCE_TYPE [TYPH,TYPH] := TYPH;
    COMPARE_COERCE_TYPE [TYPQ,TYPUJ] := TYPUJ;
    COMPARE_COERCE_TYPE [TYPH,TYPUJ] := TYPUJ;
    COMPARE_COERCE_TYPE [TYPUJ,TYPQ] := TYPUJ;
    COMPARE_COERCE_TYPE [TYPUJ,TYPH] := TYPUJ;
    COMPARE_COERCE_TYPE [TYPUJ,TYPUJ] := TYPUJ;
    COMPARE_COERCE_TYPE [TYPQ,TYPUL] := TYPUJ;
    COMPARE_COERCE_TYPE [TYPH,TYPUL] := TYPUJ;
    COMPARE_COERCE_TYPE [TYPUL,TYPQ] := TYPUJ;
    COMPARE_COERCE_TYPE [TYPUL,TYPH] := TYPUJ;
    COMPARE_COERCE_TYPE [TYPUL,TYPUL] := TYPUJ;
    COMPARE_COERCE_TYPE [TYPUJ,TYPUL] := TYPUJ;
    COMPARE_COERCE_TYPE [TYPUL,TYPUJ] := TYPUJ;
    COMPARE_COERCE_TYPE [TYPQ,TYPUI] := TYPUI;
    COMPARE_COERCE_TYPE [TYPH,TYPUI] := TYPUI;
    COMPARE_COERCE_TYPE [TYPUJ,TYPUI] := TYPUI;
    COMPARE_COERCE_TYPE [TYPUL,TYPUI] := TYPUI;
    COMPARE_COERCE_TYPE [TYPUI,TYPQ] := TYPUI;
    COMPARE_COERCE_TYPE [TYPUI,TYPH] := TYPUI;
    COMPARE_COERCE_TYPE [TYPUI,TYPUJ] := TYPUI;
    COMPARE_COERCE_TYPE [TYPUI,TYPUL] := TYPUI;
    COMPARE_COERCE_TYPE [TYPUI,TYPUI] := TYPUI;
    COMPARE_COERCE_TYPE [TYPQ,TYPUK] := TYPUI;
    COMPARE_COERCE_TYPE [TYPH,TYPUK] := TYPUI;
    COMPARE_COERCE_TYPE [TYPUJ,TYPUK] := TYPUI;
    COMPARE_COERCE_TYPE [TYPUL,TYPUK] := TYPUK;
    COMPARE_COERCE_TYPE [TYPUK,TYPQ] := TYPUI;
    COMPARE_COERCE_TYPE [TYPUK,TYPH] := TYPUI;
    COMPARE_COERCE_TYPE [TYPUK,TYPUJ] := TYPUI;
    COMPARE_COERCE_TYPE [TYPUK,TYPUL] := TYPUK;
    COMPARE_COERCE_TYPE [TYPUK,TYPUK] := TYPUK;
    COMPARE_COERCE_TYPE [TYPUK,TYPUI] := TYPUI;
    COMPARE_COERCE_TYPE [TYPUI,TYPUK] := TYPUI;
    COMPARE_COERCE_TYPE [TYPUB,TYPUB] := TYPUB;
    COMPARE_COERCE_TYPE [TYPUC,TYPUC] := TYPUC;
    COMPARE_COERCE_TYPE [TYPUS,TYPUS] := TYPUS;

    REAL_ARITH_OP [S1S, UADD] := XFADD_S;
    REAL_ARITH_OP [S1D, UADD] := XFADD_D;
    REAL_ARITH_OP [S1S, USUB] := XFSUB_S;
    REAL_ARITH_OP [S1D, USUB] := XFSUB_D;
    REAL_ARITH_OP [S1S, UMPY] := XFMULT_S;
    REAL_ARITH_OP [S1D, UMPY] := XFMULT_D;
    REAL_ARITH_OP [S1S, UDIV] := XFDIV_S;
    REAL_ARITH_OP [S1D, UDIV] := XFDIV_D;

    COMPARE_OP [S1Q, UEQU] := XSKP_EQL_Q;
    COMPARE_OP [S1Q, UNEQ] := XSKP_NEQ_Q;
    COMPARE_OP [S1Q, UGEQ] := XSKP_GEQ_Q;
    COMPARE_OP [S1Q, UGRT] := XSKP_GTR_Q;
    COMPARE_OP [S1Q, ULEQ] := XSKP_LEQ_Q;
    COMPARE_OP [S1Q, ULES] := XSKP_LSS_Q;
    COMPARE_OP [S1H, UEQU] := XSKP_EQL_H;
    COMPARE_OP [S1H, UNEQ] := XSKP_NEQ_H;
    COMPARE_OP [S1H, UGEQ] := XSKP_GEQ_H;
    COMPARE_OP [S1H, UGRT] := XSKP_GTR_H;
    COMPARE_OP [S1H, ULEQ] := XSKP_LEQ_H;
    COMPARE_OP [S1H, ULES] := XSKP_LSS_H;
    COMPARE_OP [S1S, UEQU] := XSKP_EQL_S;
    COMPARE_OP [S1S, UNEQ] := XSKP_NEQ_S;
    COMPARE_OP [S1S, UGEQ] := XSKP_GEQ_S;
    COMPARE_OP [S1S, UGRT] := XSKP_GTR_S;
    COMPARE_OP [S1S, ULEQ] := XSKP_LEQ_S;
    COMPARE_OP [S1S, ULES] := XSKP_LSS_S;
    COMPARE_OP [S1D, UEQU] := XSKP_EQL_D;
    COMPARE_OP [S1D, UNEQ] := XSKP_NEQ_D;
    COMPARE_OP [S1D, UGEQ] := XSKP_GEQ_D;
    COMPARE_OP [S1D, UGRT] := XSKP_GTR_D;
    COMPARE_OP [S1D, ULEQ] := XSKP_LEQ_D;
    COMPARE_OP [S1D, ULES] := XSKP_LSS_D;

    BLKCMP_X_Q [UEQU] := XBLCMP_EQL_Q;
    BLKCMP_X_Q [UNEQ] := XBLCMP_NEQ_Q;
    BLKCMP_X_Q [UGEQ] := XBLCMP_GEQ_Q;
    BLKCMP_X_Q [UGRT] := XBLCMP_GTR_Q;
    BLKCMP_X_Q [ULEQ] := XBLCMP_LEQ_Q;
    BLKCMP_X_Q [ULES] := XBLCMP_LSS_Q;

    for I := 1 to MAXLVL do
	LVL_TO_S1REG[I] := MAXDSPS1REG + 1 - I;

    for I := 0 to MAXPAREGM1 do
	PRM_TO_S1REG[I] := I + MINPARS1REG;

    for I := FIRSTS1REG to LASTS1REG do
	S1REG_TO_PRM[I] := 1000000;
    for I := MINPARS1REG to (MAXPAREGM1+MINPARS1REG) do
	S1REG_TO_PRM[I] := I - MINPARS1REG;

    ZSEGTYPE_TO_CHARS [ZIS] := 'IS  ';
    ZSEGTYPE_TO_CHARS [ZDS] := 'DS  ';
    ZSEGTYPE_TO_CHARS [ZCM] := 'CM  ';

    ZESDTYPE_TO_CHARS [ZST] := 'ST  ';
    ZESDTYPE_TO_CHARS [ZIN] := 'IN  ';
    ZESDTYPE_TO_CHARS [ZDN] := 'DN  ';
    ZESDTYPE_TO_CHARS [ZAN] := 'AN  ';

    ZESRTYPE_TO_CHARS [ZIR] := 'IR  ';
    ZESRTYPE_TO_CHARS [ZDR] := 'DR  ';
    ZESRTYPE_TO_CHARS [ZAR] := 'AR  ';
    ZESRTYPE_TO_CHARS [ZXR] := 'XR  ';

    ZOPR_TO_CHARS [ZPLUS] := '+ ';
    ZOPR_TO_CHARS [ZMINUS] := '- ';

    ZIXFLAG_TO_CHAR [ZESD] := 'D';
    ZIXFLAG_TO_CHAR [ZESR] := 'R';
    ZIXFLAG_TO_CHAR [ZSEG] := 'S';

    for I := 0 to OPCHTSIZEM1 do
	begin
	OPCHASHTAB[I].OPCNAM := '    ';
	end;

    ENTER_OPC ('ABS ', UABS);       ENTER_OPC ('ADD ', UADD);
    ENTER_OPC ('SUB ', USUB);       ENTER_OPC ('MPY ', UMPY);
    ENTER_OPC ('DIV ', UDIV);       ENTER_OPC ('ADJ ', UADJ);
    ENTER_OPC ('AND ', UAND);       ENTER_OPC ('BGN ', UBGN);
    ENTER_OPC ('BGNB', UBGNB);      ENTER_OPC ('CHKF', UCHKF);
    ENTER_OPC ('CHKH', UCHKH);      ENTER_OPC ('CHKL', UCHKL);
    ENTER_OPC ('CHKN', UCHKN);      ENTER_OPC ('CHKT', UCHKT);
    ENTER_OPC ('CLAB', UCLAB);      ENTER_OPC ('COMM', UCOMM);
    ENTER_OPC ('CSP ', UCSP);       ENTER_OPC ('CUP ', UCUP);
    ENTER_OPC ('CVT ', UCVT);       ENTER_OPC ('CVT2', UCVT2);
    ENTER_OPC ('DEAD', UDEAD);      ENTER_OPC ('DEC ', UDEC);
    ENTER_OPC ('DEF ', UDEF);       ENTER_OPC ('DIF ', UDIF);
    ENTER_OPC ('DMD ', UDMD);       ENTER_OPC ('DOA ', UDOA);
    ENTER_OPC ('DSP ', UDSP);       ENTER_OPC ('DUP ', UDUP);
    ENTER_OPC ('END ', UEND);       ENTER_OPC ('ENDB', UENDB);
    ENTER_OPC ('ENT ', UENT);       ENTER_OPC ('EXPP', UEXPP);
    ENTER_OPC ('EXPV', UEXPV);      ENTER_OPC ('FJP ', UFJP);
    ENTER_OPC ('ICUP', UICUP);      ENTER_OPC ('EQU ', UEQU);
    ENTER_OPC ('NEQ ', UNEQ);       ENTER_OPC ('GEQ ', UGEQ);
    ENTER_OPC ('GOOB', UGOOB);
    ENTER_OPC ('GRT ', UGRT);       ENTER_OPC ('LEQ ', ULEQ);
    ENTER_OPC ('LES ', ULES);       ENTER_OPC ('IEQU', UIEQU);
    ENTER_OPC ('INEQ', UINEQ);      ENTER_OPC ('IGEQ', UIGEQ);
    ENTER_OPC ('IGRT', UIGRT);      ENTER_OPC ('ILEQ', UILEQ);
    ENTER_OPC ('ILES', UILES);      ENTER_OPC ('ILOD', UILOD);
    ENTER_OPC ('MOV ', UMOV);       ENTER_OPC ('IMPP', UIMPP);
    ENTER_OPC ('IMPV', UIMPV);      ENTER_OPC ('INC ', UINC);
    ENTER_OPC ('INN ', UINN);       ENTER_OPC ('INST', UINST);
    ENTER_OPC ('INT ', UINT);       ENTER_OPC ('IOR ', UIOR);
    ENTER_OPC ('ISTR', UISTR);      ENTER_OPC ('IXA ', UIXA);
    ENTER_OPC ('LAB ', ULAB);       ENTER_OPC ('LCA ', ULCA);
    ENTER_OPC ('LDA ', ULDA);       ENTER_OPC ('LDC ', ULDC);
    ENTER_OPC ('LDP ', ULDP);       ENTER_OPC ('LEX ', ULEX);
    ENTER_OPC ('LIVE', ULIVE);      ENTER_OPC ('LOC ', ULOC);
    ENTER_OPC ('LOD ', ULOD);       ENTER_OPC ('MDEF', UMDEF);
    ENTER_OPC ('MOD ', UMOD);       ENTER_OPC ('MST ', UMST);
    ENTER_OPC ('MUS ', UMUS);       ENTER_OPC ('NEG ', UNEG);
    ENTER_OPC ('NEW ', UNEW);       ENTER_OPC ('NOT ', UNOT);
    ENTER_OPC ('NSTR', UNSTR);      ENTER_OPC ('ODD ', UODD);
    ENTER_OPC ('OPTN', UOPTN);      ENTER_OPC ('PAR ', UPAR);
    ENTER_OPC ('PLEX', UPLEX);      ENTER_OPC ('PLOD', UPLOD);
    ENTER_OPC ('PSTR', UPSTR);      ENTER_OPC ('RET ', URET);
    ENTER_OPC ('RND ', URND);       ENTER_OPC ('SDEF', USDEF);
    ENTER_OPC ('SGS ', USGS);       ENTER_OPC ('SQR ', USQR);
    ENTER_OPC ('STP ', USTP);       ENTER_OPC ('STR ', USTR);
    ENTER_OPC ('SWP ', USWP);       ENTER_OPC ('SYM ', USYM);
    ENTER_OPC ('TJP ', UTJP);       ENTER_OPC ('TYP ', UTYP);
    ENTER_OPC ('TYP2', UTYP2);      ENTER_OPC ('UJP ', UUJP);
    ENTER_OPC ('UNI ', UUNI);       ENTER_OPC ('UNK ', UUNK);
    ENTER_OPC ('XJP ', UXJP);       ENTER_OPC ('XOR ', UXOR);
	     
    end (*INIT2*);

(** INITIALIZE_CLASS:			INIT3 **)
(**)

    procedure INIT3;
    begin
    for I := 0 to CSPHTSIZEM1 do
	begin
	CSPHASHTAB[I].CSPNAM.NAM := '                ';
	CSPHASHTAB[I].CSPNAM.LEN := 1;
	end;

    ENTER_CSP ('ATN', QATN);	    ENTER_CSP ('EXP', QEXP);
    ENTER_CSP ('SIN', QSIN);	    ENTER_CSP ('COS', QCOS);
    ENTER_CSP ('LOG', QLOG);	    ENTER_CSP ('SQT', QSQT);
    ENTER_CSP ('CLK', QCLK);	    ENTER_CSP ('XIT', QXIT);
    ENTER_CSP ('TRP', QTRP);	    ENTER_CSP ('GET', QGET);
    ENTER_CSP ('PUT', QPUT);	    ENTER_CSP ('RLN', QRLN);
    ENTER_CSP ('WLN', QWLN);	    ENTER_CSP ('RES', QRES);
    ENTER_CSP ('REW', QREW);	    ENTER_CSP ('RDC', QRDC);
    ENTER_CSP ('RDI', QRDI);	    ENTER_CSP ('RDR', QRDR);
    ENTER_CSP ('RDS', QRDS);	    ENTER_CSP ('WRC', QWRC);
    ENTER_CSP ('RDB', QRDB);	    ENTER_CSP ('WRB', QWRB);
    ENTER_CSP ('WRI', QWRI);	    ENTER_CSP ('WRR', QWRR);
    ENTER_CSP ('WRS', QWRS);	    ENTER_CSP ('ELN', QELN);
    ENTER_CSP ('EOF', QEOF);	    ENTER_CSP ('SIO', QSIO);
    ENTER_CSP ('EIO', QEIO);	    ENTER_CSP ('NEW', QNEW);
    ENTER_CSP ('SAV', QSAV);	    ENTER_CSP ('RST', QRST);
    ENTER_CSP ('RND', QRND);					(*ROUND*)


    for S1OP := FIRSTS1OP to LASTS1OP do
	REVERSE_OP[S1OP] := XILLEGAL;

    REVERSE_OP[XADD_S]	  := XADD_S;
    REVERSE_OP[XADD_D]	  := XADD_D;
    REVERSE_OP[XAND_Q]	  := XAND_Q;
    REVERSE_OP[XAND_D]	  := XAND_D;
    REVERSE_OP[XAND_TC_D] := XAND_CT_D;
    REVERSE_OP[XAND_CT_D] := XAND_TC_D;
    REVERSE_OP[XDSKP_EQL] := XDSKP_EQL;				(*25JUN79 PTZ...*)
    REVERSE_OP[XDSKP_NEQ] := XDSKP_NEQ;
    REVERSE_OP[XDSKP_GEQ] := XDSKP_LEQ;
    REVERSE_OP[XDSKP_GTR] := XDSKP_LSS;
    REVERSE_OP[XDSKP_LEQ] := XDSKP_GEQ;
    REVERSE_OP[XDSKP_LSS] := XDSKP_GTR;				(*...25JUN79 PTZ*)
    REVERSE_OP[XFADD_S] := XFADD_S;
    REVERSE_OP[XFADD_D] := XFADD_D;
    REVERSE_OP[XFSUB_S] := XFSUBV_S;
    REVERSE_OP[XFSUBV_S] := XFSUB_S;
    REVERSE_OP[XFSUB_D]  := XFSUBV_D;
    REVERSE_OP[XFSUBV_D] := XFSUB_D;
    REVERSE_OP[XFMULT_S] := XFMULT_S;
    REVERSE_OP[XFMULT_D] := XFMULT_D;
    REVERSE_OP[XFDIV_S]  := XFDIVV_S;
    REVERSE_OP[XFDIVV_S] := XFDIV_S;
    REVERSE_OP[XFDIV_D]  := XFDIVV_D;
    REVERSE_OP[XFDIVV_D] := XFDIV_D;
    REVERSE_OP[XISKP_EQL] := XISKP_EQL;				(*25JUN79 PTZ...*)
    REVERSE_OP[XISKP_NEQ] := XISKP_NEQ;
    REVERSE_OP[XISKP_GEQ] := XISKP_LEQ;
    REVERSE_OP[XISKP_GTR] := XISKP_LSS;
    REVERSE_OP[XISKP_LEQ] := XISKP_GEQ;
    REVERSE_OP[XISKP_LSS] := XISKP_GTR;				(*...25JUN79 PTZ*)
    REVERSE_OP[XMULT_S] := XMULT_S;
    REVERSE_OP[XMULT_D] := XMULT_D;
    REVERSE_OP[XNOP] := XNOP;
    REVERSE_OP[XOR_Q]	:= XOR_Q;
    REVERSE_OP[XOR_D]	:= XOR_D;
    REVERSE_OP[XQUO_S]	   := XQUOV_S;
    REVERSE_OP[XQUOV_S]    := XQUO_S;
    REVERSE_OP[XQUO_D]	   := XQUOV_D;
    REVERSE_OP[XQUOV_D]    := XQUO_D;
    REVERSE_OP[XREM_S]	:= XREMV_S;
    REVERSE_OP[XREMV_S] := XREM_S;
    REVERSE_OP[XREM_D]	:= XREMV_D;
    REVERSE_OP[XREMV_D] := XREM_D;
    REVERSE_OP[XSHF_LF_D]   := XSHFV_LF_D;
    REVERSE_OP[XSHFV_LF_D]  := XSHF_LF_D;
    REVERSE_OP[XSHFA_LF_S]  := XSHFAV_LF_S;
    REVERSE_OP[XSHFAV_LF_S] := XSHFA_LF_S;
    REVERSE_OP[XSKP_EQL_Q] := XSKP_EQL_Q;    (*unused at this time 25JUN79 PTZ...*)
    REVERSE_OP[XSKP_NEQ_Q] := XSKP_NEQ_Q;
    REVERSE_OP[XSKP_GEQ_Q] := XSKP_LEQ_Q;
    REVERSE_OP[XSKP_GTR_Q] := XSKP_LSS_Q;
    REVERSE_OP[XSKP_LEQ_Q] := XSKP_GEQ_Q;
    REVERSE_OP[XSKP_LSS_Q] := XSKP_GTR_Q;
    REVERSE_OP[XSKP_EQL_H] := XSKP_EQL_H;
    REVERSE_OP[XSKP_NEQ_H] := XSKP_NEQ_H;
    REVERSE_OP[XSKP_GEQ_H] := XSKP_LEQ_H;
    REVERSE_OP[XSKP_GTR_H] := XSKP_LSS_H;
    REVERSE_OP[XSKP_LEQ_H] := XSKP_GEQ_H;
    REVERSE_OP[XSKP_LSS_H] := XSKP_GTR_H;
    REVERSE_OP[XSKP_EQL_S] := XSKP_EQL_S;
    REVERSE_OP[XSKP_NEQ_S] := XSKP_NEQ_S;
    REVERSE_OP[XSKP_GEQ_S] := XSKP_LEQ_S;
    REVERSE_OP[XSKP_GTR_S] := XSKP_LSS_S;
    REVERSE_OP[XSKP_LEQ_S] := XSKP_GEQ_S;
    REVERSE_OP[XSKP_LSS_S] := XSKP_GTR_S;
    REVERSE_OP[XSKP_EQL_D] := XSKP_EQL_D;
    REVERSE_OP[XSKP_NEQ_D] := XSKP_NEQ_D;
    REVERSE_OP[XSKP_GEQ_D] := XSKP_LEQ_D;
    REVERSE_OP[XSKP_GTR_D] := XSKP_LSS_D;
    REVERSE_OP[XSKP_LEQ_D] := XSKP_GEQ_D;
    REVERSE_OP[XSKP_LSS_D] := XSKP_GTR_D;
    REVERSE_OP[XSKP_NON_Q] := XSKP_NON_Q;
    REVERSE_OP[XSKP_NON_H] := XSKP_NON_H;
    REVERSE_OP[XSKP_NON_S] := XSKP_NON_S;
    REVERSE_OP[XSKP_NON_D] := XSKP_NON_D;
    REVERSE_OP[XSKP_ANY_Q] := XSKP_ANY_Q;
    REVERSE_OP[XSKP_ANY_H] := XSKP_ANY_H;
    REVERSE_OP[XSKP_ANY_S] := XSKP_ANY_S;
    REVERSE_OP[XSKP_ANY_D] := XSKP_ANY_D;    (*...unused at this time 25JUN79 PTZ*)
    REVERSE_OP[XSUB_S]	:= XSUBV_S;
    REVERSE_OP[XSUBV_S] := XSUB_S;
    REVERSE_OP[XSUB_D]	:= XSUBV_D;
    REVERSE_OP[XSUBV_D] := XSUB_D;
    REVERSE_OP[XXOR_Q]	:= XXOR_Q;

    OPFORMAT [XILLEGAL] := VFAKEOP;
    OPFORMAT [XPLOC]  := VFAKEOP;
    OPFORMAT [XS1LOC] := VFAKEOP;
    OPFORMAT [XFREEREG] := VFAKEOP;					(*PBK*)

    OPFORMAT [XABS_Q] := VXOP;
    OPFORMAT [XABS_H] := VXOP;
    OPFORMAT [XABS_S] := VXOP;
    OPFORMAT [XABS_D] := VXOP;
    OPFORMAT [XADD_S] := VTOP;
    OPFORMAT [XADD_D] := VTOP;
    OPFORMAT [XADJSP_UP] := VXOP;
    OPFORMAT [XADJSP_DN] := VXOP;
    OPFORMAT [XALLOC_1] := VXOP;
    OPFORMAT [XAND_Q] := VTOP;
    OPFORMAT [XAND_D] := VTOP;
    OPFORMAT [XAND_TC_D] := VTOP;
    OPFORMAT [XAND_CT_D] := VTOP;
    OPFORMAT [XBLCMP_EQL_Q] := VXOP;
    OPFORMAT [XBLCMP_NEQ_Q] := VXOP;
    OPFORMAT [XBLCMP_GEQ_Q] := VXOP;
    OPFORMAT [XBLCMP_GTR_Q] := VXOP;
    OPFORMAT [XBLCMP_LEQ_Q] := VXOP;
    OPFORMAT [XBLCMP_LSS_Q] := VXOP;
    OPFORMAT [XBLKMOV] := VXOP;
    OPFORMAT [XBTRP_B_Q] := VXOP;
    OPFORMAT [XBTRP_B_H] := VXOP;
    OPFORMAT [XBTRP_B_S] := VXOP;
    OPFORMAT [XBTRP_B_D] := VXOP;
    OPFORMAT [XBTRP_M1_Q] := VXOP;
    OPFORMAT [XBTRP_M1_H] := VXOP;
    OPFORMAT [XBTRP_M1_S] := VXOP;
    OPFORMAT [XBTRP_M1_D] := VXOP;
    OPFORMAT [XBTRP_0_Q] := VXOP;
    OPFORMAT [XBTRP_0_H] := VXOP;
    OPFORMAT [XBTRP_0_S] := VXOP;
    OPFORMAT [XBTRP_0_D] := VXOP;
    OPFORMAT [XBTRP_1_Q] := VXOP;
    OPFORMAT [XBTRP_1_H] := VXOP;
    OPFORMAT [XBTRP_1_S] := VXOP;
    OPFORMAT [XBTRP_1_D] := VXOP;
    OPFORMAT [XDEC_S]  := VXOP;
    OPFORMAT [XDJMPA]  := VJOP;					(*25JUN79 PTZ...*)
    OPFORMAT [XDSKP_EQL] := VSOP;
    OPFORMAT [XDSKP_NEQ] := VSOP;
    OPFORMAT [XDSKP_GEQ] := VSOP;
    OPFORMAT [XDSKP_GTR] := VSOP;
    OPFORMAT [XDSKP_LEQ] := VSOP;
    OPFORMAT [XDSKP_LSS] := VSOP;				(*...25JUN79 PTZ*)
    OPFORMAT [XFX_DM_S_S]  := VXOP;
    OPFORMAT [XFX_DM_S_D]  := VXOP;
    OPFORMAT [XFX_FL_S_S]  := VXOP;
    OPFORMAT [XFLOAT_S_Q] := VXOP;
    OPFORMAT [XFLOAT_S_H] := VXOP;
    OPFORMAT [XFLOAT_S_S] := VXOP;
    OPFORMAT [XFLOAT_S_D] := VXOP;
    OPFORMAT [XFADD_S]  := VTOP;
    OPFORMAT [XFADD_D]  := VTOP;
    OPFORMAT [XFSUB_S]  := VTOP;
    OPFORMAT [XFSUBV_S] := VTOP;
    OPFORMAT [XFSUB_D]  := VTOP;
    OPFORMAT [XFSUBV_D] := VTOP;
    OPFORMAT [XFMULT_S] := VTOP;
    OPFORMAT [XFMULT_D] := VTOP;
    OPFORMAT [XFDIV_S]  := VTOP;
    OPFORMAT [XFDIVV_S] := VTOP;
    OPFORMAT [XFDIV_D]  := VTOP;
    OPFORMAT [XFDIVV_D] := VTOP;
    OPFORMAT [XFTRANS_S_D] := VXOP;
    OPFORMAT [XFTRANS_D_S] := VXOP;
    OPFORMAT [XHALT]	   := VJOP;			       (*BNDTRPKLU*)
    OPFORMAT [XIJMPA]	   := VJOP;				(*25JUN79 PTZ*)
    OPFORMAT [XINC_S]	   := VXOP;
    OPFORMAT [XISKP_EQL] := VSOP;				(*25JUN79 PTZ...*)
    OPFORMAT [XISKP_NEQ] := VSOP;
    OPFORMAT [XISKP_GEQ] := VSOP;
    OPFORMAT [XISKP_GTR] := VSOP;
    OPFORMAT [XISKP_LEQ] := VSOP;
    OPFORMAT [XISKP_LSS] := VSOP;				(*...25JUN79 PTZ*)
    OPFORMAT [XJMPA] := VJOP;
    OPFORMAT [XJMPZ_EQL_Q] := VJOP;
    OPFORMAT [XJMPZ_NEQ_Q] := VJOP;		(* als/peg 19jul79 *)
    OPFORMAT [XJSR]   := VJOP;
    OPFORMAT [XMOV_A] := VXOP;
    OPFORMAT [XMOV_Q_Q] := VXOP;
    OPFORMAT [XMOV_Q_H] := VXOP;
    OPFORMAT [XMOV_H_Q] := VXOP;
    OPFORMAT [XMOV_H_H] := VXOP;
    OPFORMAT [XMOV_Q_S] := VXOP;
    OPFORMAT [XMOV_H_S] := VXOP;
    OPFORMAT [XMOV_S_Q] := VXOP;
    OPFORMAT [XMOV_S_H] := VXOP;
    OPFORMAT [XMOV_S_S] := VXOP;
    OPFORMAT [XMOV_Q_D] := VXOP;
    OPFORMAT [XMOV_H_D] := VXOP;
    OPFORMAT [XMOV_S_D] := VXOP;
    OPFORMAT [XMOV_D_Q] := VXOP;
    OPFORMAT [XMOV_D_H] := VXOP;
    OPFORMAT [XMOV_D_S] := VXOP;
    OPFORMAT [XMOV_D_D] := VXOP;
    OPFORMAT [XMOVMQ_2] := VXOP;
    OPFORMAT [XMOVMQ_3] := VXOP;
    OPFORMAT [XMOVMQ_4] := VXOP;
    OPFORMAT [XMOVMQ_5] := VXOP;
    OPFORMAT [XMOVMQ_6] := VXOP;
    OPFORMAT [XMOVMQ_7] := VXOP;
    OPFORMAT [XMOVMQ_8] := VXOP;
    OPFORMAT [XMOVMQ_9] := VXOP;
    OPFORMAT [XMOVMQ_10] := VXOP;
    OPFORMAT [XMOVMQ_11] := VXOP;
    OPFORMAT [XMOVMQ_12] := VXOP;
    OPFORMAT [XMOVMQ_13] := VXOP;
    OPFORMAT [XMOVMQ_14] := VXOP;
    OPFORMAT [XMOVMQ_15] := VXOP;
    OPFORMAT [XMOVMQ_16] := VXOP;
    OPFORMAT [XMOVMQ_17] := VXOP;
    OPFORMAT [XMOVMQ_18] := VXOP;
    OPFORMAT [XMOVMQ_19] := VXOP;
    OPFORMAT [XMOVMQ_20] := VXOP;
    OPFORMAT [XMOVMQ_21] := VXOP;
    OPFORMAT [XMOVMQ_22] := VXOP;
    OPFORMAT [XMOVMQ_23] := VXOP;
    OPFORMAT [XMOVMQ_24] := VXOP;
    OPFORMAT [XMOVMQ_25] := VXOP;
    OPFORMAT [XMOVMQ_26] := VXOP;
    OPFORMAT [XMOVMQ_27] := VXOP;
    OPFORMAT [XMOVMQ_28] := VXOP;
    OPFORMAT [XMOVMQ_29] := VXOP;
    OPFORMAT [XMOVMQ_30] := VXOP;
    OPFORMAT [XMOVMQ_31] := VXOP;
    OPFORMAT [XMOVMQ_32] := VXOP;
    OPFORMAT [XMOVMQ_64] := VXOP;
    OPFORMAT [XMOVMQ_128] := VXOP;
    OPFORMAT [XMOVMS_2] := VXOP;	(*ALS*)
    OPFORMAT [XMOVMS_3] := VXOP;
    OPFORMAT [XMOVMS_4] := VXOP;
    OPFORMAT [XMOVMS_5] := VXOP;
    OPFORMAT [XMOVMS_6] := VXOP;
    OPFORMAT [XMOVMS_7] := VXOP;
    OPFORMAT [XMOVMS_8] := VXOP;
    OPFORMAT [XMOVMS_9] := VXOP;
    OPFORMAT [XMOVMS_10] := VXOP;
    OPFORMAT [XMOVMS_11] := VXOP;
    OPFORMAT [XMOVMS_12] := VXOP;
    OPFORMAT [XMOVMS_13] := VXOP;
    OPFORMAT [XMOVMS_14] := VXOP;
    OPFORMAT [XMOVMS_15] := VXOP;
    OPFORMAT [XMOVMS_16] := VXOP;
    OPFORMAT [XMOVMS_17] := VXOP;
    OPFORMAT [XMOVMS_18] := VXOP;
    OPFORMAT [XMOVMS_19] := VXOP;
    OPFORMAT [XMOVMS_20] := VXOP;
    OPFORMAT [XMOVMS_21] := VXOP;
    OPFORMAT [XMOVMS_22] := VXOP;
    OPFORMAT [XMOVMS_23] := VXOP;
    OPFORMAT [XMOVMS_24] := VXOP;
    OPFORMAT [XMOVMS_25] := VXOP;
    OPFORMAT [XMOVMS_26] := VXOP;
    OPFORMAT [XMOVMS_27] := VXOP;
    OPFORMAT [XMOVMS_28] := VXOP;
    OPFORMAT [XMOVMS_29] := VXOP;
    OPFORMAT [XMOVMS_30] := VXOP;
    OPFORMAT [XMOVMS_31] := VXOP;
    OPFORMAT [XMOVMS_32] := VXOP;	(*ALS*)
    OPFORMAT [XMULT_S]	:= VTOP;
    OPFORMAT [XMULT_D]	:= VTOP;
    OPFORMAT [XDIV_S] := VTOP;		(* als/peg 18jul79 *)
    OPFORMAT [XNEG_Q] := VXOP;
    OPFORMAT [XNEG_H] := VXOP;
    OPFORMAT [XNEG_S] := VXOP;
    OPFORMAT [XNEG_D] := VXOP;
    OPFORMAT [XNOP]  := VXOP;
    OPFORMAT [XOR_Q]  := VTOP;
    OPFORMAT [XOR_D]  := VTOP;
    OPFORMAT [XQUO_S]  := VTOP;
    OPFORMAT [XQUOV_S] := VTOP;
    OPFORMAT [XQUO_D]  := VTOP;
    OPFORMAT [XQUOV_D] := VTOP;
    OPFORMAT [XREM_S]  := VTOP;
    OPFORMAT [XREMV_S] := VTOP;
    OPFORMAT [XREM_D]  := VTOP;
    OPFORMAT [XREMV_D] := VTOP;
    OPFORMAT [XRETSR] := VXOP;
    OPFORMAT [XSHF_LF_D]  := VTOP;
    OPFORMAT [XSHFV_LF_D] := VTOP;
    OPFORMAT [XSHFA_LF_S] := VTOP;
    OPFORMAT [XSHFAV_LF_S] := VTOP;
    OPFORMAT [XSKP_EQL_Q] := VSOP;
    OPFORMAT [XSKP_NEQ_Q] := VSOP;
    OPFORMAT [XSKP_GEQ_Q] := VSOP;
    OPFORMAT [XSKP_GTR_Q] := VSOP;
    OPFORMAT [XSKP_LEQ_Q] := VSOP;
    OPFORMAT [XSKP_LSS_Q] := VSOP;
    OPFORMAT [XSKP_EQL_H] := VSOP;
    OPFORMAT [XSKP_NEQ_H] := VSOP;
    OPFORMAT [XSKP_GEQ_H] := VSOP;
    OPFORMAT [XSKP_GTR_H] := VSOP;
    OPFORMAT [XSKP_LEQ_H] := VSOP;
    OPFORMAT [XSKP_LSS_H] := VSOP;
    OPFORMAT [XSKP_EQL_S] := VSOP;
    OPFORMAT [XSKP_NEQ_S] := VSOP;
    OPFORMAT [XSKP_GEQ_S] := VSOP;
    OPFORMAT [XSKP_GTR_S] := VSOP;
    OPFORMAT [XSKP_LEQ_S] := VSOP;
    OPFORMAT [XSKP_LSS_S] := VSOP;
    OPFORMAT [XSKP_EQL_D] := VSOP;
    OPFORMAT [XSKP_NEQ_D] := VSOP;
    OPFORMAT [XSKP_GEQ_D] := VSOP;
    OPFORMAT [XSKP_GTR_D] := VSOP;
    OPFORMAT [XSKP_LEQ_D] := VSOP;
    OPFORMAT [XSKP_LSS_D] := VSOP;
    OPFORMAT [XSKP_NON_Q] := VSOP;
    OPFORMAT [XSKP_NON_H] := VSOP;
    OPFORMAT [XSKP_NON_S] := VSOP;
    OPFORMAT [XSKP_NON_D] := VSOP;
    OPFORMAT [XSKP_ANY_Q] := VSOP;
    OPFORMAT [XSKP_ANY_H] := VSOP;
    OPFORMAT [XSKP_ANY_S] := VSOP;
    OPFORMAT [XSKP_ANY_D] := VSOP;
    OPFORMAT [XSLR_0] := VXOP;
    OPFORMAT [XSLR_1] := VXOP;
    OPFORMAT [XSLR_2] := VXOP;
    OPFORMAT [XSLR_3] := VXOP;
    OPFORMAT [XSLR_4] := VXOP;
    OPFORMAT [XSLR_5] := VXOP;
    OPFORMAT [XSLR_6] := VXOP;
    OPFORMAT [XSLR_7] := VXOP;
    OPFORMAT [XSLR_8] := VXOP;
    OPFORMAT [XSLR_9] := VXOP;
    OPFORMAT [XSLR_10] := VXOP;
    OPFORMAT [XSLR_11] := VXOP;
    OPFORMAT [XSLR_12] := VXOP;
    OPFORMAT [XSLR_13] := VXOP;
    OPFORMAT [XSLR_14] := VXOP;
    OPFORMAT [XSLR_15] := VXOP;
    OPFORMAT [XSLR_16] := VXOP;
    OPFORMAT [XSLR_17] := VXOP;
    OPFORMAT [XSLR_18] := VXOP;
    OPFORMAT [XSLR_19] := VXOP;
    OPFORMAT [XSLR_20] := VXOP;
    OPFORMAT [XSLR_21] := VXOP;
    OPFORMAT [XSLR_22] := VXOP;
    OPFORMAT [XSLR_23] := VXOP;
    OPFORMAT [XSLR_24] := VXOP;
    OPFORMAT [XSLR_25] := VXOP;
    OPFORMAT [XSLR_26] := VXOP;
    OPFORMAT [XSLR_27] := VXOP;
    OPFORMAT [XSLR_28] := VXOP;
    OPFORMAT [XSLR_29] := VXOP;
    OPFORMAT [XSLR_30] := VXOP;
    OPFORMAT [XSLR_31] := VXOP;
    OPFORMAT [XSLRADR_0] := VXOP;
    OPFORMAT [XSLRADR_1] := VXOP;
    OPFORMAT [XSLRADR_2] := VXOP;
    OPFORMAT [XSLRADR_3] := VXOP;
    OPFORMAT [XSLRADR_4] := VXOP;
    OPFORMAT [XSLRADR_5] := VXOP;
    OPFORMAT [XSLRADR_6] := VXOP;
    OPFORMAT [XSLRADR_7] := VXOP;
    OPFORMAT [XSLRADR_8] := VXOP;
    OPFORMAT [XSLRADR_9] := VXOP;
    OPFORMAT [XSLRADR_10] := VXOP;
    OPFORMAT [XSLRADR_11] := VXOP;
    OPFORMAT [XSLRADR_12] := VXOP;
    OPFORMAT [XSLRADR_13] := VXOP;
    OPFORMAT [XSLRADR_14] := VXOP;
    OPFORMAT [XSLRADR_15] := VXOP;
    OPFORMAT [XSLRADR_16] := VXOP;
    OPFORMAT [XSLRADR_17] := VXOP;
    OPFORMAT [XSLRADR_18] := VXOP;
    OPFORMAT [XSLRADR_19] := VXOP;
    OPFORMAT [XSLRADR_20] := VXOP;
    OPFORMAT [XSLRADR_21] := VXOP;
    OPFORMAT [XSLRADR_22] := VXOP;
    OPFORMAT [XSLRADR_23] := VXOP;
    OPFORMAT [XSLRADR_24] := VXOP;
    OPFORMAT [XSLRADR_25] := VXOP;
    OPFORMAT [XSLRADR_26] := VXOP;
    OPFORMAT [XSLRADR_27] := VXOP;
    OPFORMAT [XSLRADR_28] := VXOP;
    OPFORMAT [XSLRADR_29] := VXOP;
    OPFORMAT [XSLRADR_30] := VXOP;
    OPFORMAT [XSLRADR_31] := VXOP;
    OPFORMAT [XSUB_S]  := VTOP;
    OPFORMAT [XSUBV_S] := VTOP;
    OPFORMAT [XSUB_D]  := VTOP;
    OPFORMAT [XSUBV_D] := VTOP;
    OPFORMAT [XTRANS_Q_Q] := VXOP;
    OPFORMAT [XTRANS_Q_H] := VXOP;
    OPFORMAT [XTRANS_H_Q] := VXOP;
    OPFORMAT [XTRANS_H_H] := VXOP;
    OPFORMAT [XTRANS_Q_S] := VXOP;
    OPFORMAT [XTRANS_H_S] := VXOP;
    OPFORMAT [XTRANS_S_Q] := VXOP;
    OPFORMAT [XTRANS_S_H] := VXOP;
    OPFORMAT [XTRANS_S_S] := VXOP;
    OPFORMAT [XTRANS_Q_D] := VXOP;
    OPFORMAT [XTRANS_H_D] := VXOP;
    OPFORMAT [XTRANS_S_D] := VXOP;
    OPFORMAT [XTRANS_D_Q] := VXOP;
    OPFORMAT [XTRANS_D_H] := VXOP;
    OPFORMAT [XTRANS_D_S] := VXOP;
    OPFORMAT [XTRANS_D_D] := VXOP;
    OPFORMAT [XXOR_Q]  := VTOP;


    end (*INIT3*);

(** INITIALIZE_CLASS:			INIT4 **)
(**)

    procedure INIT4;
    begin
    S1MNEM [XILLEGAL]	    :=	'ILLEGAL	';
    S1MNEM [XPLOC]	    :=	'ULOC		';
    S1MNEM [XS1LOC]	    :=	'S1LOC		';
    S1MNEM [XFREEREG]	    :=  'FREEREG	';			(*PBK*)

(* START S1MNEM MARKER FOR OPS.PAS *)
    S1MNEM [XABS_Q]         :=  'ABS.Q          ';
    S1MNEM [XABS_H]         :=  'ABS.H          ';
    S1MNEM [XABS_S]         :=  'ABS.S          ';
    S1MNEM [XABS_D]         :=  'ABS.D          ';
    S1MNEM [XADD_S]         :=  'ADD.S          ';
    S1MNEM [XADD_D]         :=  'ADD.D          ';
    S1MNEM [XADJSP_UP]      :=  'ADJSP.UP       ';
    S1MNEM [XADJSP_DN]      :=  'ADJSP.DN       ';
    S1MNEM [XALLOC_1]       :=  'ALLOC.1        ';
    S1MNEM [XAND_Q]         :=  'AND.Q          ';
    S1MNEM [XAND_D]         :=  'AND.D          ';
    S1MNEM [XAND_TC_D]      :=  'ANDTC.D        ';
    S1MNEM [XAND_CT_D]      :=  'ANDCT.D        ';
    S1MNEM [XBLCMP_EQL_Q]   :=  'BLKCMP.EQL.Q   ';
    S1MNEM [XBLCMP_NEQ_Q]   :=  'BLKCMP.NEQ.Q   ';
    S1MNEM [XBLCMP_GEQ_Q]   :=  'BLKCMP.GEQ.Q   ';
    S1MNEM [XBLCMP_GTR_Q]   :=  'BLKCMP.GTR.Q   ';
    S1MNEM [XBLCMP_LEQ_Q]   :=  'BLKCMP.LEQ.Q   ';
    S1MNEM [XBLCMP_LSS_Q]   :=  'BLKCMP.LSS.Q   ';
    S1MNEM [XBLKMOV] 	    :=  'BLKMOV         ';
    S1MNEM [XBTRP_B_Q]      :=  'BNDTRP.B.Q     ';
    S1MNEM [XBTRP_B_H]      :=  'BNDTRP.B.H     ';
    S1MNEM [XBTRP_B_S]      :=  'BNDTRP.B.S     ';
    S1MNEM [XBTRP_B_D]      :=  'BNDTRP.B.D     ';
    S1MNEM [XBTRP_M1_Q]     :=  'BNDTRP.M1.Q    ';
    S1MNEM [XBTRP_M1_H]     :=  'BNDTRP.M1.H    ';
    S1MNEM [XBTRP_M1_S]     :=  'BNDTRP.M1.S    ';
    S1MNEM [XBTRP_M1_D]     :=  'BNDTRP.M1.D    ';
    S1MNEM [XBTRP_0_Q]      :=  'BNDTRP.0.Q     ';
    S1MNEM [XBTRP_0_H]      :=  'BNDTRP.0.H     ';
    S1MNEM [XBTRP_0_S]      :=  'BNDTRP.0.S     ';
    S1MNEM [XBTRP_0_D]      :=  'BNDTRP.0.D     ';
    S1MNEM [XBTRP_1_Q]      :=  'BNDTRP.1.Q     ';
    S1MNEM [XBTRP_1_H]      :=  'BNDTRP.1.H     ';
    S1MNEM [XBTRP_1_S]      :=  'BNDTRP.1.S     ';
    S1MNEM [XBTRP_1_D]      :=  'BNDTRP.1.D     ';
    S1MNEM [XDEC_S]         :=  'DEC.S          ';
    S1MNEM [XDJMPA]	    :=  'DJMPA          ';
    S1MNEM [XDSKP_EQL]	    :=  'DSKP.EQL       ';
    S1MNEM [XDSKP_NEQ]	    :=  'DSKP.NEQ       ';
    S1MNEM [XDSKP_GEQ]	    :=  'DSKP.GEQ       ';
    S1MNEM [XDSKP_GTR]	    :=  'DSKP.GTR       ';
    S1MNEM [XDSKP_LEQ]	    :=  'DSKP.LEQ       ';
    S1MNEM [XDSKP_LSS]	    :=  'DSKP.LSS       ';
    S1MNEM [XFX_DM_S_S]     :=  'FIX.DM.S.S     ';
    S1MNEM [XFX_DM_S_D]     :=  'FIX.DM.S.D     ';
    S1MNEM [XFX_FL_S_S]	    :=  'FIX.FL.S.S     ';
    S1MNEM [XFLOAT_S_Q]     :=  'FLOAT.S.Q      ';
    S1MNEM [XFLOAT_S_H]     :=  'FLOAT.S.H      ';
    S1MNEM [XFLOAT_S_S]     :=  'FLOAT.S.S      ';
    S1MNEM [XFLOAT_S_D]     :=  'FLOAT.S.D      ';
    S1MNEM [XFADD_S]        :=  'FADD.S         ';
    S1MNEM [XFADD_D]        :=  'FADD.D         ';
    S1MNEM [XFSUB_S]        :=  'FSUB.S         ';
    S1MNEM [XFSUBV_S]       :=  'FSUBV.S        ';
    S1MNEM [XFSUB_D]        :=  'FSUB.D         ';
    S1MNEM [XFSUBV_D]       :=  'FSUBV.D        ';
    S1MNEM [XFMULT_S]       :=  'FMULT.S        ';
    S1MNEM [XFMULT_D]       :=  'FMULT.D        ';
    S1MNEM [XFDIV_S]        :=  'FDIV.S         ';
    S1MNEM [XFDIVV_S]       :=  'FDIVV.S        ';
    S1MNEM [XFDIV_D]        :=  'FDIV.D         ';
    S1MNEM [XFDIVV_D]       :=  'FDIVV.D        ';
    S1MNEM [XFTRANS_S_D]    :=  'FTRANS.S.D     ';
    S1MNEM [XFTRANS_D_S]    :=  'FTRANS.D.S     ';
    S1MNEM [XHALT]          :=  'HALT           ';
    S1MNEM [XIJMPA]	    :=  'IJMPA          ';
    S1MNEM [XINC_S]         :=  'INC.S          ';
    S1MNEM [XISKP_EQL]	    :=  'ISKP.EQL       ';
    S1MNEM [XISKP_NEQ]	    :=  'ISKP.NEQ       ';
    S1MNEM [XISKP_GEQ]	    :=  'ISKP.GEQ       ';
    S1MNEM [XISKP_GTR]	    :=  'ISKP.GTR       ';
    S1MNEM [XISKP_LEQ]	    :=  'ISKP.LEQ       ';
    S1MNEM [XISKP_LSS]	    :=  'ISKP.LSS       ';
    S1MNEM [XJMPA]	    :=  'JMPA           ';
    S1MNEM [XJMPZ_EQL_Q]    :=  'JMPZ.EQL.Q     ';
    S1MNEM [XJMPZ_NEQ_Q]    :=  'JMPZ.NEQ.Q     ';
    S1MNEM [XJSR]           :=  'JSR            ';
    S1MNEM [XMOV_A]         :=  'MOVADR         ';
    S1MNEM [XMOV_Q_Q]       :=  'MOV.Q.Q        ';
    S1MNEM [XMOV_Q_H]       :=  'MOV.Q.H        ';
    S1MNEM [XMOV_H_Q]       :=  'MOV.H.Q        ';
    S1MNEM [XMOV_H_H]       :=  'MOV.H.H        ';
    S1MNEM [XMOV_Q_S]       :=  'MOV.Q.S        ';
    S1MNEM [XMOV_H_S]       :=  'MOV.H.S        ';
    S1MNEM [XMOV_S_Q]       :=  'MOV.S.Q        ';
    S1MNEM [XMOV_S_H]       :=  'MOV.S.H        ';
    S1MNEM [XMOV_S_S]       :=  'MOV.S.S        ';
    S1MNEM [XMOV_Q_D]       :=  'MOV.Q.D        ';
    S1MNEM [XMOV_H_D]       :=  'MOV.H.D        ';
    S1MNEM [XMOV_S_D]       :=  'MOV.S.D        ';
    S1MNEM [XMOV_D_Q]       :=  'MOV.D.Q        ';
    S1MNEM [XMOV_D_H]       :=  'MOV.D.H        ';
    S1MNEM [XMOV_D_S]       :=  'MOV.D.S        ';
    S1MNEM [XMOV_D_D]       :=  'MOV.D.D        ';
    S1MNEM [XMOVMQ_2]       :=  'MOVMQ.2        ';
    S1MNEM [XMOVMQ_3]       :=  'MOVMQ.3        ';
    S1MNEM [XMOVMQ_4]       :=  'MOVMQ.4        ';
    S1MNEM [XMOVMQ_5]       :=  'MOVMQ.5        ';
    S1MNEM [XMOVMQ_6]       :=  'MOVMQ.6        ';
    S1MNEM [XMOVMQ_7]       :=  'MOVMQ.7        ';
    S1MNEM [XMOVMQ_8]       :=  'MOVMQ.8        ';
    S1MNEM [XMOVMQ_9]       :=  'MOVMQ.9        ';
    S1MNEM [XMOVMQ_10]      :=  'MOVMQ.10       ';
    S1MNEM [XMOVMQ_11]      :=  'MOVMQ.11       ';
    S1MNEM [XMOVMQ_12]      :=  'MOVMQ.12       ';
    S1MNEM [XMOVMQ_13]      :=  'MOVMQ.13       ';
    S1MNEM [XMOVMQ_14]      :=  'MOVMQ.14       ';
    S1MNEM [XMOVMQ_15]      :=  'MOVMQ.15       ';
    S1MNEM [XMOVMQ_16]      :=  'MOVMQ.16       ';
    S1MNEM [XMOVMQ_17]      :=  'MOVMQ.17       ';
    S1MNEM [XMOVMQ_18]      :=  'MOVMQ.18       ';
    S1MNEM [XMOVMQ_19]      :=  'MOVMQ.19       ';
    S1MNEM [XMOVMQ_20]      :=  'MOVMQ.20       ';
    S1MNEM [XMOVMQ_21]      :=  'MOVMQ.21       ';
    S1MNEM [XMOVMQ_22]      :=  'MOVMQ.22       ';
    S1MNEM [XMOVMQ_23]      :=  'MOVMQ.23       ';
    S1MNEM [XMOVMQ_24]      :=  'MOVMQ.24       ';
    S1MNEM [XMOVMQ_25]      :=  'MOVMQ.25       ';
    S1MNEM [XMOVMQ_26]      :=  'MOVMQ.26       ';
    S1MNEM [XMOVMQ_27]      :=  'MOVMQ.27       ';
    S1MNEM [XMOVMQ_28]      :=  'MOVMQ.28       ';
    S1MNEM [XMOVMQ_29]      :=  'MOVMQ.29       ';
    S1MNEM [XMOVMQ_30]      :=  'MOVMQ.30       ';
    S1MNEM [XMOVMQ_31]      :=  'MOVMQ.31       ';
    S1MNEM [XMOVMQ_32]      :=  'MOVMQ.32       ';
    S1MNEM [XMOVMQ_64]      :=  'MOVMQ.64       ';
    S1MNEM [XMOVMQ_128]     :=  'MOVMQ.128      ';
    S1MNEM [XMOVMS_2]       :=  'MOVMS.2        ';
    S1MNEM [XMOVMS_3]       :=  'MOVMS.3        ';
    S1MNEM [XMOVMS_4]       :=  'MOVMS.4        ';
    S1MNEM [XMOVMS_5]       :=  'MOVMS.5        ';
    S1MNEM [XMOVMS_6]       :=  'MOVMS.6        ';
    S1MNEM [XMOVMS_7]       :=  'MOVMS.7        ';
    S1MNEM [XMOVMS_8]       :=  'MOVMS.8        ';
    S1MNEM [XMOVMS_9]       :=  'MOVMS.9        ';
    S1MNEM [XMOVMS_10]      :=  'MOVMS.10       ';
    S1MNEM [XMOVMS_11]      :=  'MOVMS.11       ';
    S1MNEM [XMOVMS_12]      :=  'MOVMS.12       ';
    S1MNEM [XMOVMS_13]      :=  'MOVMS.13       ';
    S1MNEM [XMOVMS_14]      :=  'MOVMS.14       ';
    S1MNEM [XMOVMS_15]      :=  'MOVMS.15       ';
    S1MNEM [XMOVMS_16]      :=  'MOVMS.16       ';
    S1MNEM [XMOVMS_17]      :=  'MOVMS.17       ';
    S1MNEM [XMOVMS_18]      :=  'MOVMS.18       ';
    S1MNEM [XMOVMS_19]      :=  'MOVMS.19       ';
    S1MNEM [XMOVMS_20]      :=  'MOVMS.20       ';
    S1MNEM [XMOVMS_21]      :=  'MOVMS.21       ';
    S1MNEM [XMOVMS_22]      :=  'MOVMS.22       ';
    S1MNEM [XMOVMS_23]      :=  'MOVMS.23       ';
    S1MNEM [XMOVMS_24]      :=  'MOVMS.24       ';
    S1MNEM [XMOVMS_25]      :=  'MOVMS.25       ';
    S1MNEM [XMOVMS_26]      :=  'MOVMS.26       ';
    S1MNEM [XMOVMS_27]      :=  'MOVMS.27       ';
    S1MNEM [XMOVMS_28]      :=  'MOVMS.28       ';
    S1MNEM [XMOVMS_29]      :=  'MOVMS.29       ';
    S1MNEM [XMOVMS_30]      :=  'MOVMS.30       ';
    S1MNEM [XMOVMS_31]      :=  'MOVMS.31       ';
    S1MNEM [XMOVMS_32]      :=  'MOVMS.32       ';
    S1MNEM [XMULT_S]        :=  'MULT.S         ';
    S1MNEM [XMULT_D]        :=  'MULT.D         ';
    S1MNEM [XDIV_S]         :=  'DIV.S          ';
    S1MNEM [XNEG_Q]         :=  'NEG.Q          ';
    S1MNEM [XNEG_H]         :=  'NEG.H          ';
    S1MNEM [XNEG_S]         :=  'NEG.S          ';
    S1MNEM [XNEG_D]         :=  'NEG.D          ';
    S1MNEM [XNOP]           :=  'NOP            ';
    S1MNEM [XOR_Q]          :=  'OR.Q           ';
    S1MNEM [XOR_D]          :=  'OR.D           ';
    S1MNEM [XQUO_S]         :=  'QUO.S          ';
    S1MNEM [XQUOV_S]        :=  'QUOV.S         ';
    S1MNEM [XQUO_D]         :=  'QUO.D          ';
    S1MNEM [XQUOV_D]        :=  'QUOV.D         ';
    S1MNEM [XREM_S]         :=  'REM.S          ';
    S1MNEM [XREMV_S]        :=  'REMV.S         ';
    S1MNEM [XREM_D]         :=  'REM.D          ';
    S1MNEM [XREMV_D]        :=  'REMV.D         ';
    S1MNEM [XRETSR]         :=  'RETSR          ';
    S1MNEM [XSHF_LF_D]      :=  'SHF.LF.D       ';
    S1MNEM [XSHFV_LF_D]     :=  'SHFV.LF.D      ';
    S1MNEM [XSHFA_LF_S]     :=  'SHFA.LF.S      ';
    S1MNEM [XSHFAV_LF_S]    :=  'SHFAV.LF.S     ';
    S1MNEM [XSKP_EQL_Q]     :=  'SKP.EQL.Q      ';
    S1MNEM [XSKP_NEQ_Q]     :=  'SKP.NEQ.Q      ';
    S1MNEM [XSKP_GEQ_Q]     :=  'SKP.GEQ.Q      ';
    S1MNEM [XSKP_GTR_Q]     :=  'SKP.GTR.Q      ';
    S1MNEM [XSKP_LEQ_Q]     :=  'SKP.LEQ.Q      ';
    S1MNEM [XSKP_LSS_Q]     :=  'SKP.LSS.Q      ';
    S1MNEM [XSKP_EQL_H]     :=  'SKP.EQL.H      ';
    S1MNEM [XSKP_NEQ_H]     :=  'SKP.NEQ.H      ';
    S1MNEM [XSKP_GEQ_H]     :=  'SKP.GEQ.H      ';
    S1MNEM [XSKP_GTR_H]     :=  'SKP.GTR.H      ';
    S1MNEM [XSKP_LEQ_H]     :=  'SKP.LEQ.H      ';
    S1MNEM [XSKP_LSS_H]     :=  'SKP.LSS.H      ';
    S1MNEM [XSKP_EQL_S]     :=  'SKP.EQL.S      ';
    S1MNEM [XSKP_NEQ_S]     :=  'SKP.NEQ.S      ';
    S1MNEM [XSKP_GEQ_S]     :=  'SKP.GEQ.S      ';
    S1MNEM [XSKP_GTR_S]     :=  'SKP.GTR.S      ';
    S1MNEM [XSKP_LEQ_S]     :=  'SKP.LEQ.S      ';
    S1MNEM [XSKP_LSS_S]     :=  'SKP.LSS.S      ';
    S1MNEM [XSKP_EQL_D]     :=  'SKP.EQL.D      ';
    S1MNEM [XSKP_NEQ_D]     :=  'SKP.NEQ.D      ';
    S1MNEM [XSKP_GEQ_D]     :=  'SKP.GEQ.D      ';
    S1MNEM [XSKP_GTR_D]     :=  'SKP.GTR.D      ';
    S1MNEM [XSKP_LEQ_D]     :=  'SKP.LEQ.D      ';
    S1MNEM [XSKP_LSS_D]     :=  'SKP.LSS.D      ';
    S1MNEM [XSKP_NON_Q]     :=  'SKP.NON.Q      ';
    S1MNEM [XSKP_NON_H]     :=  'SKP.NON.H      ';
    S1MNEM [XSKP_NON_S]     :=  'SKP.NON.S      ';
    S1MNEM [XSKP_NON_D]     :=  'SKP.NON.D      ';
    S1MNEM [XSKP_ANY_Q]     :=  'SKP.ANY.Q      ';
    S1MNEM [XSKP_ANY_H]     :=  'SKP.ANY.H      ';
    S1MNEM [XSKP_ANY_S]     :=  'SKP.ANY.S      ';
    S1MNEM [XSKP_ANY_D]     :=  'SKP.ANY.D      ';
    S1MNEM [XSLR_0]         :=  'SLR.0          ';
    S1MNEM [XSLR_1]         :=  'SLR.1          ';
    S1MNEM [XSLR_2]         :=  'SLR.2          ';
    S1MNEM [XSLR_3]         :=  'SLR.3          ';
    S1MNEM [XSLR_4]         :=  'SLR.4          ';
    S1MNEM [XSLR_5]         :=  'SLR.5          ';
    S1MNEM [XSLR_6]         :=  'SLR.6          ';
    S1MNEM [XSLR_7]         :=  'SLR.7          ';
    S1MNEM [XSLR_8]         :=  'SLR.8          ';
    S1MNEM [XSLR_9]         :=  'SLR.9          ';
    S1MNEM [XSLR_10]        :=  'SLR.10         ';
    S1MNEM [XSLR_11]        :=  'SLR.11         ';
    S1MNEM [XSLR_12]        :=  'SLR.12         ';
    S1MNEM [XSLR_13]        :=  'SLR.13         ';
    S1MNEM [XSLR_14]        :=  'SLR.14         ';
    S1MNEM [XSLR_15]        :=  'SLR.15         ';
    S1MNEM [XSLR_16]        :=  'SLR.16         ';
    S1MNEM [XSLR_17]        :=  'SLR.17         ';
    S1MNEM [XSLR_18]        :=  'SLR.18         ';
    S1MNEM [XSLR_19]        :=  'SLR.19         ';
    S1MNEM [XSLR_20]        :=  'SLR.20         ';
    S1MNEM [XSLR_21]        :=  'SLR.21         ';
    S1MNEM [XSLR_22]        :=  'SLR.22         ';
    S1MNEM [XSLR_23]        :=  'SLR.23         ';
    S1MNEM [XSLR_24]        :=  'SLR.24         ';
    S1MNEM [XSLR_25]        :=  'SLR.25         ';
    S1MNEM [XSLR_26]        :=  'SLR.26         ';
    S1MNEM [XSLR_27]        :=  'SLR.27         ';
    S1MNEM [XSLR_28]        :=  'SLR.28         ';
    S1MNEM [XSLR_29]        :=  'SLR.29         ';
    S1MNEM [XSLR_30]        :=  'SLR.30         ';
    S1MNEM [XSLR_31]        :=  'SLR.31         ';
    S1MNEM [XSLRADR_0]      :=  'SLRADR.0       ';
    S1MNEM [XSLRADR_1]      :=  'SLRADR.1       ';
    S1MNEM [XSLRADR_2]      :=  'SLRADR.2       ';
    S1MNEM [XSLRADR_3]      :=  'SLRADR.3       ';
    S1MNEM [XSLRADR_4]      :=  'SLRADR.4       ';
    S1MNEM [XSLRADR_5]      :=  'SLRADR.5       ';
    S1MNEM [XSLRADR_6]      :=  'SLRADR.6       ';
    S1MNEM [XSLRADR_7]      :=  'SLRADR.7       ';
    S1MNEM [XSLRADR_8]      :=  'SLRADR.8       ';
    S1MNEM [XSLRADR_9]      :=  'SLRADR.9       ';
    S1MNEM [XSLRADR_10]     :=  'SLRADR.10      ';
    S1MNEM [XSLRADR_11]     :=  'SLRADR.11      ';
    S1MNEM [XSLRADR_12]     :=  'SLRADR.12      ';
    S1MNEM [XSLRADR_13]     :=  'SLRADR.13      ';
    S1MNEM [XSLRADR_14]     :=  'SLRADR.14      ';
    S1MNEM [XSLRADR_15]     :=  'SLRADR.15      ';
    S1MNEM [XSLRADR_16]     :=  'SLRADR.16      ';
    S1MNEM [XSLRADR_17]     :=  'SLRADR.17      ';
    S1MNEM [XSLRADR_18]     :=  'SLRADR.18      ';
    S1MNEM [XSLRADR_19]     :=  'SLRADR.19      ';
    S1MNEM [XSLRADR_20]     :=  'SLRADR.20      ';
    S1MNEM [XSLRADR_21]     :=  'SLRADR.21      ';
    S1MNEM [XSLRADR_22]     :=  'SLRADR.22      ';
    S1MNEM [XSLRADR_23]     :=  'SLRADR.23      ';
    S1MNEM [XSLRADR_24]     :=  'SLRADR.24      ';
    S1MNEM [XSLRADR_25]     :=  'SLRADR.25      ';
    S1MNEM [XSLRADR_26]     :=  'SLRADR.26      ';
    S1MNEM [XSLRADR_27]     :=  'SLRADR.27      ';
    S1MNEM [XSLRADR_28]     :=  'SLRADR.28      ';
    S1MNEM [XSLRADR_29]     :=  'SLRADR.29      ';
    S1MNEM [XSLRADR_30]     :=  'SLRADR.30      ';
    S1MNEM [XSLRADR_31]     :=  'SLRADR.31      ';
    S1MNEM [XSUB_S]         :=  'SUB.S          ';
    S1MNEM [XSUBV_S]        :=  'SUBV.S         ';
    S1MNEM [XSUB_D]         :=  'SUB.D          ';
    S1MNEM [XSUBV_D]        :=  'SUBV.D         ';
    S1MNEM [XTRANS_Q_Q]     :=  'TRANS.Q.Q      ';
    S1MNEM [XTRANS_Q_H]     :=  'TRANS.Q.H      ';
    S1MNEM [XTRANS_H_Q]     :=  'TRANS.H.Q      ';
    S1MNEM [XTRANS_H_H]     :=  'TRANS.H.H      ';
    S1MNEM [XTRANS_Q_S]     :=  'TRANS.Q.S      ';
    S1MNEM [XTRANS_H_S]     :=  'TRANS.H.S      ';
    S1MNEM [XTRANS_S_Q]     :=  'TRANS.S.Q      ';
    S1MNEM [XTRANS_S_H]     :=  'TRANS.S.H      ';
    S1MNEM [XTRANS_S_S]     :=  'TRANS.S.S      ';
    S1MNEM [XTRANS_Q_D]     :=  'TRANS.Q.D      ';
    S1MNEM [XTRANS_H_D]     :=  'TRANS.H.D      ';
    S1MNEM [XTRANS_S_D]     :=  'TRANS.S.D      ';
    S1MNEM [XTRANS_D_Q]     :=  'TRANS.D.Q      ';
    S1MNEM [XTRANS_D_H]     :=  'TRANS.D.H      ';
    S1MNEM [XTRANS_D_S]     :=  'TRANS.D.S      ';
    S1MNEM [XTRANS_D_D]     :=  'TRANS.D.D      ';
    S1MNEM [XXOR_Q]         :=  'XOR.Q          ';
(* END S1MNEM MARKER FOR OPS.PAS *)

    end (*INIT4*);

(** INITIALIZE_CLASS:			INIT5 **)
(**)

    procedure INIT5;
    begin

(* HARDOPCODEs for FAKEOPs should start at 4095 and work down.	 	 PBK*)

    HARDOPCODE [XILLEGAL            ]  :=   4095;			(*PBK*)
    HARDOPCODE [XPLOC	            ]  :=   4094;			(*PBK*)
    HARDOPCODE [XS1LOC	            ]  :=   4093;			(*PBK*)
    HARDOPCODE [XFREEREG            ]  :=   4092;			(*PBK*)

(* GENERATED SOPA OPCODES USING OPS.IN OF 13DEC78 2219 JBR *)
    HARDOPCODE [XABS_Q              ] := 1487;
    HARDOPCODE [XABS_H              ] := 1488;
    HARDOPCODE [XABS_S              ] := 1489;
    HARDOPCODE [XABS_D              ] := 1490;
    HARDOPCODE [XADD_S              ] :=   12;
    HARDOPCODE [XADD_D              ] :=   16;
    HARDOPCODE [XADJSP_UP           ] := 1830;
    HARDOPCODE [XADJSP_DN           ] := 1831;
    HARDOPCODE [XALLOC_1            ] := 1666;
    HARDOPCODE [XAND_Q              ] :=  736;
    HARDOPCODE [XAND_D              ] :=  748;
    HARDOPCODE [XAND_TC_D           ] :=  764;
    HARDOPCODE [XAND_CT_D           ] :=  780;
    HARDOPCODE [XBLCMP_EQL_Q        ] := 1866;
    HARDOPCODE [XBLCMP_NEQ_Q        ] := 1878;
    HARDOPCODE [XBLCMP_GEQ_Q        ] := 1870;
    HARDOPCODE [XBLCMP_GTR_Q        ] := 1862;
    HARDOPCODE [XBLCMP_LEQ_Q        ] := 1882;
    HARDOPCODE [XBLCMP_LSS_Q        ] := 1874;
    HARDOPCODE [XBLKMOV             ] := 1886;
    HARDOPCODE [XBTRP_B_Q           ] := 1645;
    HARDOPCODE [XBTRP_B_H           ] := 1646;
    HARDOPCODE [XBTRP_B_S           ] := 1647;
    HARDOPCODE [XBTRP_B_D           ] := 1648;
    HARDOPCODE [XBTRP_M1_Q          ] := 1653;
    HARDOPCODE [XBTRP_M1_H          ] := 1654;
    HARDOPCODE [XBTRP_M1_S          ] := 1655;
    HARDOPCODE [XBTRP_M1_D          ] := 1656;
    HARDOPCODE [XBTRP_0_Q           ] := 1657;
    HARDOPCODE [XBTRP_0_H           ] := 1658;
    HARDOPCODE [XBTRP_0_S           ] := 1659;
    HARDOPCODE [XBTRP_0_D           ] := 1660;
    HARDOPCODE [XBTRP_1_Q           ] := 1661;
    HARDOPCODE [XBTRP_1_H           ] := 1662;
    HARDOPCODE [XBTRP_1_S           ] := 1663;
    HARDOPCODE [XBTRP_1_D           ] := 1664;
    HARDOPCODE [XDEC_S              ] := 1384;
    HARDOPCODE [XDJMPA              ] := 1348;
    HARDOPCODE [XDSKP_EQL           ] := 2800;
    HARDOPCODE [XDSKP_NEQ           ] := 2848;
    HARDOPCODE [XDSKP_GEQ           ] := 2816;
    HARDOPCODE [XDSKP_GTR           ] := 2784;
    HARDOPCODE [XDSKP_LEQ           ] := 2864;
    HARDOPCODE [XDSKP_LSS           ] := 2832;
    HARDOPCODE [XFX_DM_S_S          ] := 1433;
    HARDOPCODE [XFX_DM_S_D          ] := 1434;
    HARDOPCODE [XFX_FL_S_S          ] := 1409;
    HARDOPCODE [XFLOAT_S_Q          ] := 1466;
    HARDOPCODE [XFLOAT_S_H          ] := 1467;
    HARDOPCODE [XFLOAT_S_S          ] := 1468;
    HARDOPCODE [XFLOAT_S_D          ] := 1469;
    HARDOPCODE [XFADD_S             ] :=  412;
    HARDOPCODE [XFADD_D             ] :=  416;
    HARDOPCODE [XFSUB_S             ] :=  424;
    HARDOPCODE [XFSUBV_S            ] :=  436;
    HARDOPCODE [XFSUB_D             ] :=  428;
    HARDOPCODE [XFSUBV_D            ] :=  440;
    HARDOPCODE [XFMULT_S            ] :=  448;
    HARDOPCODE [XFMULT_D            ] :=  452;
    HARDOPCODE [XFDIV_S             ] :=  468;
    HARDOPCODE [XFDIVV_S            ] :=  480;
    HARDOPCODE [XFDIV_D             ] :=  472;
    HARDOPCODE [XFDIVV_D            ] :=  484;
    HARDOPCODE [XFTRANS_S_D         ] := 1479;
    HARDOPCODE [XFTRANS_D_S         ] := 1481;
    HARDOPCODE [XHALT               ] := 1376;
    HARDOPCODE [XIJMPA              ] := 1322;
    HARDOPCODE [XINC_S              ] := 1380;
    HARDOPCODE [XISKP_EQL           ] := 2704;
    HARDOPCODE [XISKP_NEQ           ] := 2752;
    HARDOPCODE [XISKP_GEQ           ] := 2720;
    HARDOPCODE [XISKP_GTR           ] := 2688;
    HARDOPCODE [XISKP_LEQ           ] := 2768;
    HARDOPCODE [XISKP_LSS           ] := 2736;
    HARDOPCODE [XJMPA               ] := 1296;
    HARDOPCODE [XJMPZ_EQL_Q         ] := 1256;
    HARDOPCODE [XJMPZ_NEQ_Q         ] := 1280;
    HARDOPCODE [XJSR                ] := 1350;
    HARDOPCODE [XMOV_A              ] := 1639;
    HARDOPCODE [XMOV_Q_Q            ] := 1491;
    HARDOPCODE [XMOV_Q_H            ] := 1492;
    HARDOPCODE [XMOV_H_Q            ] := 1495;
    HARDOPCODE [XMOV_H_H            ] := 1496;
    HARDOPCODE [XMOV_Q_S            ] := 1493;
    HARDOPCODE [XMOV_H_S            ] := 1497;
    HARDOPCODE [XMOV_S_Q            ] := 1499;
    HARDOPCODE [XMOV_S_H            ] := 1500;
    HARDOPCODE [XMOV_S_S            ] := 1501;
    HARDOPCODE [XMOV_Q_D            ] := 1494;
    HARDOPCODE [XMOV_H_D            ] := 1498;
    HARDOPCODE [XMOV_S_D            ] := 1502;
    HARDOPCODE [XMOV_D_Q            ] := 1503;
    HARDOPCODE [XMOV_D_H            ] := 1504;
    HARDOPCODE [XMOV_D_S            ] := 1505;
    HARDOPCODE [XMOV_D_D            ] := 1506;
    HARDOPCODE [XMOVMQ_2            ] := 1507;
    HARDOPCODE [XMOVMQ_3            ] := 1508;
    HARDOPCODE [XMOVMQ_4            ] := 1509;
    HARDOPCODE [XMOVMQ_5            ] := 1510;
    HARDOPCODE [XMOVMQ_6            ] := 1511;
    HARDOPCODE [XMOVMQ_7            ] := 1512;
    HARDOPCODE [XMOVMQ_8            ] := 1513;
    HARDOPCODE [XMOVMQ_9            ] := 1514;
    HARDOPCODE [XMOVMQ_10           ] := 1515;
    HARDOPCODE [XMOVMQ_11           ] := 1516;
    HARDOPCODE [XMOVMQ_12           ] := 1517;
    HARDOPCODE [XMOVMQ_13           ] := 1518;
    HARDOPCODE [XMOVMQ_14           ] := 1519;
    HARDOPCODE [XMOVMQ_15           ] := 1520;
    HARDOPCODE [XMOVMQ_16           ] := 1521;
    HARDOPCODE [XMOVMQ_17           ] := 1522;
    HARDOPCODE [XMOVMQ_18           ] := 1523;
    HARDOPCODE [XMOVMQ_19           ] := 1524;
    HARDOPCODE [XMOVMQ_20           ] := 1525;
    HARDOPCODE [XMOVMQ_21           ] := 1526;
    HARDOPCODE [XMOVMQ_22           ] := 1527;
    HARDOPCODE [XMOVMQ_23           ] := 1528;
    HARDOPCODE [XMOVMQ_24           ] := 1529;
    HARDOPCODE [XMOVMQ_25           ] := 1530;
    HARDOPCODE [XMOVMQ_26           ] := 1531;
    HARDOPCODE [XMOVMQ_27           ] := 1532;
    HARDOPCODE [XMOVMQ_28           ] := 1533;
    HARDOPCODE [XMOVMQ_29           ] := 1534;
    HARDOPCODE [XMOVMQ_30           ] := 1535;
    HARDOPCODE [XMOVMQ_31           ] := 1536;
    HARDOPCODE [XMOVMQ_32           ] := 1537;
    HARDOPCODE [XMOVMQ_64           ] := 1538;
    HARDOPCODE [XMOVMQ_128          ] := 1539;
    HARDOPCODE [XMOVMS_2            ] := 1540;
    HARDOPCODE [XMOVMS_3            ] := 1541;
    HARDOPCODE [XMOVMS_4            ] := 1542;
    HARDOPCODE [XMOVMS_5            ] := 1543;
    HARDOPCODE [XMOVMS_6            ] := 1544;
    HARDOPCODE [XMOVMS_7            ] := 1545;
    HARDOPCODE [XMOVMS_8            ] := 1546;
    HARDOPCODE [XMOVMS_9            ] := 1547;
    HARDOPCODE [XMOVMS_10           ] := 1548;
    HARDOPCODE [XMOVMS_11           ] := 1549;
    HARDOPCODE [XMOVMS_12           ] := 1550;
    HARDOPCODE [XMOVMS_13           ] := 1551;
    HARDOPCODE [XMOVMS_14           ] := 1552;
    HARDOPCODE [XMOVMS_15           ] := 1553;
    HARDOPCODE [XMOVMS_16           ] := 1554;
    HARDOPCODE [XMOVMS_17           ] := 1555;
    HARDOPCODE [XMOVMS_18           ] := 1556;
    HARDOPCODE [XMOVMS_19           ] := 1557;
    HARDOPCODE [XMOVMS_20           ] := 1558;
    HARDOPCODE [XMOVMS_21           ] := 1559;
    HARDOPCODE [XMOVMS_22           ] := 1560;
    HARDOPCODE [XMOVMS_23           ] := 1561;
    HARDOPCODE [XMOVMS_24           ] := 1562;
    HARDOPCODE [XMOVMS_25           ] := 1563;
    HARDOPCODE [XMOVMS_26           ] := 1564;
    HARDOPCODE [XMOVMS_27           ] := 1565;
    HARDOPCODE [XMOVMS_28           ] := 1566;
    HARDOPCODE [XMOVMS_29           ] := 1567;
    HARDOPCODE [XMOVMS_30           ] := 1568;
    HARDOPCODE [XMOVMS_31           ] := 1569;
    HARDOPCODE [XMOVMS_32           ] := 1570;
    HARDOPCODE [XMULT_S             ] :=  108;
    HARDOPCODE [XMULT_D             ] :=  112;
    HARDOPCODE [XDIV_S              ] :=  360;
    HARDOPCODE [XNEG_Q              ] := 1483;
    HARDOPCODE [XNEG_H              ] := 1484;
    HARDOPCODE [XNEG_S              ] := 1485;
    HARDOPCODE [XNEG_D              ] := 1486;
    HARDOPCODE [XNOP                ] := 1939;
    HARDOPCODE [XOR_Q               ] :=  784;
    HARDOPCODE [XOR_D               ] :=  796;
    HARDOPCODE [XQUO_S              ] :=  136;
    HARDOPCODE [XQUOV_S             ] :=  152;
    HARDOPCODE [XQUO_D              ] :=  140;
    HARDOPCODE [XQUOV_D             ] :=  156;
    HARDOPCODE [XREM_S              ] :=  248;
    HARDOPCODE [XREMV_S             ] :=  264;
    HARDOPCODE [XREM_D              ] :=  252;
    HARDOPCODE [XREMV_D             ] :=  268;
    HARDOPCODE [XRETSR              ] := 1698;
    HARDOPCODE [XSHF_LF_D           ] :=  908;
    HARDOPCODE [XSHFV_LF_D          ] :=  940;
    HARDOPCODE [XSHFA_LF_S          ] := 1016;
    HARDOPCODE [XSHFAV_LF_S         ] := 1048;
    HARDOPCODE [XSKP_EQL_Q          ] := 2112;
    HARDOPCODE [XSKP_NEQ_Q          ] := 2304;
    HARDOPCODE [XSKP_GEQ_Q          ] := 2176;
    HARDOPCODE [XSKP_GTR_Q          ] := 2048;
    HARDOPCODE [XSKP_LEQ_Q          ] := 2368;
    HARDOPCODE [XSKP_LSS_Q          ] := 2240;
    HARDOPCODE [XSKP_EQL_H          ] := 2128;
    HARDOPCODE [XSKP_NEQ_H          ] := 2320;
    HARDOPCODE [XSKP_GEQ_H          ] := 2192;
    HARDOPCODE [XSKP_GTR_H          ] := 2064;
    HARDOPCODE [XSKP_LEQ_H          ] := 2384;
    HARDOPCODE [XSKP_LSS_H          ] := 2256;
    HARDOPCODE [XSKP_EQL_S          ] := 2144;
    HARDOPCODE [XSKP_NEQ_S          ] := 2336;
    HARDOPCODE [XSKP_GEQ_S          ] := 2208;
    HARDOPCODE [XSKP_GTR_S          ] := 2080;
    HARDOPCODE [XSKP_LEQ_S          ] := 2400;
    HARDOPCODE [XSKP_LSS_S          ] := 2272;
    HARDOPCODE [XSKP_EQL_D          ] := 2160;
    HARDOPCODE [XSKP_NEQ_D          ] := 2352;
    HARDOPCODE [XSKP_GEQ_D          ] := 2224;
    HARDOPCODE [XSKP_GTR_D          ] := 2096;
    HARDOPCODE [XSKP_LEQ_D          ] := 2416;
    HARDOPCODE [XSKP_LSS_D          ] := 2288;
    HARDOPCODE [XSKP_NON_Q          ] := 2432;
    HARDOPCODE [XSKP_NON_H          ] := 2448;
    HARDOPCODE [XSKP_NON_S          ] := 2464;
    HARDOPCODE [XSKP_NON_D          ] := 2480;
    HARDOPCODE [XSKP_ANY_Q          ] := 2624;
    HARDOPCODE [XSKP_ANY_H          ] := 2640;
    HARDOPCODE [XSKP_ANY_S          ] := 2656;
    HARDOPCODE [XSKP_ANY_D          ] := 2672;
    HARDOPCODE [XSLR_0              ] := 1575;
    HARDOPCODE [XSLR_1              ] := 1576;
    HARDOPCODE [XSLR_2              ] := 1577;
    HARDOPCODE [XSLR_3              ] := 1578;
    HARDOPCODE [XSLR_4              ] := 1579;
    HARDOPCODE [XSLR_5              ] := 1580;
    HARDOPCODE [XSLR_6              ] := 1581;
    HARDOPCODE [XSLR_7              ] := 1582;
    HARDOPCODE [XSLR_8              ] := 1583;
    HARDOPCODE [XSLR_9              ] := 1584;
    HARDOPCODE [XSLR_10             ] := 1585;
    HARDOPCODE [XSLR_11             ] := 1586;
    HARDOPCODE [XSLR_12             ] := 1587;
    HARDOPCODE [XSLR_13             ] := 1588;
    HARDOPCODE [XSLR_14             ] := 1589;
    HARDOPCODE [XSLR_15             ] := 1590;
    HARDOPCODE [XSLR_16             ] := 1591;
    HARDOPCODE [XSLR_17             ] := 1592;
    HARDOPCODE [XSLR_18             ] := 1593;
    HARDOPCODE [XSLR_19             ] := 1594;
    HARDOPCODE [XSLR_20             ] := 1595;
    HARDOPCODE [XSLR_21             ] := 1596;
    HARDOPCODE [XSLR_22             ] := 1597;
    HARDOPCODE [XSLR_23             ] := 1598;
    HARDOPCODE [XSLR_24             ] := 1599;
    HARDOPCODE [XSLR_25             ] := 1600;
    HARDOPCODE [XSLR_26             ] := 1601;
    HARDOPCODE [XSLR_27             ] := 1602;
    HARDOPCODE [XSLR_28             ] := 1603;
    HARDOPCODE [XSLR_29             ] := 1604;
    HARDOPCODE [XSLR_30             ] := 1605;
    HARDOPCODE [XSLR_31             ] := 1606;
    HARDOPCODE [XSLRADR_0           ] := 1607;
    HARDOPCODE [XSLRADR_1           ] := 1608;
    HARDOPCODE [XSLRADR_2           ] := 1609;
    HARDOPCODE [XSLRADR_3           ] := 1610;
    HARDOPCODE [XSLRADR_4           ] := 1611;
    HARDOPCODE [XSLRADR_5           ] := 1612;
    HARDOPCODE [XSLRADR_6           ] := 1613;
    HARDOPCODE [XSLRADR_7           ] := 1614;
    HARDOPCODE [XSLRADR_8           ] := 1615;
    HARDOPCODE [XSLRADR_9           ] := 1616;
    HARDOPCODE [XSLRADR_10          ] := 1617;
    HARDOPCODE [XSLRADR_11          ] := 1618;
    HARDOPCODE [XSLRADR_12          ] := 1619;
    HARDOPCODE [XSLRADR_13          ] := 1620;
    HARDOPCODE [XSLRADR_14          ] := 1621;
    HARDOPCODE [XSLRADR_15          ] := 1622;
    HARDOPCODE [XSLRADR_16          ] := 1623;
    HARDOPCODE [XSLRADR_17          ] := 1624;
    HARDOPCODE [XSLRADR_18          ] := 1625;
    HARDOPCODE [XSLRADR_19          ] := 1626;
    HARDOPCODE [XSLRADR_20          ] := 1627;
    HARDOPCODE [XSLRADR_21          ] := 1628;
    HARDOPCODE [XSLRADR_22          ] := 1629;
    HARDOPCODE [XSLRADR_23          ] := 1630;
    HARDOPCODE [XSLRADR_24          ] := 1631;
    HARDOPCODE [XSLRADR_25          ] := 1632;
    HARDOPCODE [XSLRADR_26          ] := 1633;
    HARDOPCODE [XSLRADR_27          ] := 1634;
    HARDOPCODE [XSLRADR_28          ] := 1635;
    HARDOPCODE [XSLRADR_29          ] := 1636;
    HARDOPCODE [XSLRADR_30          ] := 1637;
    HARDOPCODE [XSLRADR_31          ] := 1638;
    HARDOPCODE [XSUB_S              ] :=   44;
    HARDOPCODE [XSUBV_S             ] :=   60;
    HARDOPCODE [XSUB_D              ] :=   48;
    HARDOPCODE [XSUBV_D             ] :=   64;
    HARDOPCODE [XTRANS_Q_Q          ] := 1386;
    HARDOPCODE [XTRANS_Q_H          ] := 1387;
    HARDOPCODE [XTRANS_H_Q          ] := 1390;
    HARDOPCODE [XTRANS_H_H          ] := 1391;
    HARDOPCODE [XTRANS_Q_S          ] := 1388;
    HARDOPCODE [XTRANS_H_S          ] := 1392;
    HARDOPCODE [XTRANS_S_Q          ] := 1394;
    HARDOPCODE [XTRANS_S_H          ] := 1395;
    HARDOPCODE [XTRANS_S_S          ] := 1396;
    HARDOPCODE [XTRANS_Q_D          ] := 1389;
    HARDOPCODE [XTRANS_H_D          ] := 1393;
    HARDOPCODE [XTRANS_S_D          ] := 1397;
    HARDOPCODE [XTRANS_D_Q          ] := 1398;
    HARDOPCODE [XTRANS_D_H          ] := 1399;
    HARDOPCODE [XTRANS_D_S          ] := 1400;
    HARDOPCODE [XTRANS_D_D          ] := 1401;
    HARDOPCODE [XXOR_Q              ] :=  864;

    end (*INIT5*);

(** INITIALIZE_CLASS:			INIT6 **)
(**)

    procedure INIT6;
    begin
    for S1OP := FIRSTSKIP to LASTSKIP do
	INVERSE_SKIP[S1OP] := XILLEGAL;

    INVERSE_SKIP [XDSKP_EQL]  := XDSKP_NEQ;			(*25JUN79 PTZ...*)
    INVERSE_SKIP [XDSKP_NEQ]  := XDSKP_EQL;
    INVERSE_SKIP [XDSKP_GEQ]  := XDSKP_LSS;
    INVERSE_SKIP [XDSKP_LSS]  := XDSKP_GEQ;
    INVERSE_SKIP [XDSKP_GTR]  := XDSKP_LEQ;
    INVERSE_SKIP [XDSKP_LEQ]  := XDSKP_GTR;
    INVERSE_SKIP [XISKP_EQL]  := XISKP_NEQ;
    INVERSE_SKIP [XISKP_NEQ]  := XISKP_EQL;
    INVERSE_SKIP [XISKP_GEQ]  := XISKP_LSS;
    INVERSE_SKIP [XISKP_LSS]  := XISKP_GEQ;
    INVERSE_SKIP [XISKP_GTR]  := XISKP_LEQ;
    INVERSE_SKIP [XISKP_LEQ]  := XISKP_GTR;			(*...25JUN79 PTZ*)
    INVERSE_SKIP [XSKP_EQL_Q] := XSKP_NEQ_Q;
    INVERSE_SKIP [XSKP_NEQ_Q] := XSKP_EQL_Q;
    INVERSE_SKIP [XSKP_GEQ_Q] := XSKP_LSS_Q;
    INVERSE_SKIP [XSKP_LSS_Q] := XSKP_GEQ_Q;
    INVERSE_SKIP [XSKP_GTR_Q] := XSKP_LEQ_Q;
    INVERSE_SKIP [XSKP_LEQ_Q] := XSKP_GTR_Q;
    INVERSE_SKIP [XSKP_EQL_H] := XSKP_NEQ_H;
    INVERSE_SKIP [XSKP_NEQ_H] := XSKP_EQL_H;
    INVERSE_SKIP [XSKP_GEQ_H] := XSKP_LSS_H;
    INVERSE_SKIP [XSKP_LSS_H] := XSKP_GEQ_H;
    INVERSE_SKIP [XSKP_GTR_H] := XSKP_LEQ_H;
    INVERSE_SKIP [XSKP_LEQ_H] := XSKP_GTR_H;
    INVERSE_SKIP [XSKP_EQL_S] := XSKP_NEQ_S;
    INVERSE_SKIP [XSKP_NEQ_S] := XSKP_EQL_S;
    INVERSE_SKIP [XSKP_GEQ_S] := XSKP_LSS_S;
    INVERSE_SKIP [XSKP_LSS_S] := XSKP_GEQ_S;
    INVERSE_SKIP [XSKP_GTR_S] := XSKP_LEQ_S;
    INVERSE_SKIP [XSKP_LEQ_S] := XSKP_GTR_S;
    INVERSE_SKIP [XSKP_EQL_D] := XSKP_NEQ_D;
    INVERSE_SKIP [XSKP_NEQ_D] := XSKP_EQL_D;
    INVERSE_SKIP [XSKP_GEQ_D] := XSKP_LSS_D;
    INVERSE_SKIP [XSKP_LSS_D] := XSKP_GEQ_D;
    INVERSE_SKIP [XSKP_GTR_D] := XSKP_LEQ_D;
    INVERSE_SKIP [XSKP_LEQ_D] := XSKP_GTR_D;
    INVERSE_SKIP [XSKP_NON_Q] := XSKP_ANY_Q;
    INVERSE_SKIP [XSKP_NON_H] := XSKP_ANY_H;
    INVERSE_SKIP [XSKP_NON_S] := XSKP_ANY_S;
    INVERSE_SKIP [XSKP_NON_D] := XSKP_ANY_D;
    INVERSE_SKIP [XSKP_ANY_Q] := XSKP_NON_Q;
    INVERSE_SKIP [XSKP_ANY_H] := XSKP_NON_H;
    INVERSE_SKIP [XSKP_ANY_S] := XSKP_NON_S;
    INVERSE_SKIP [XSKP_ANY_D] := XSKP_NON_D;

    for S1OP := FIRSTS1OP to LASTS1OP do			(*28JUN79 PTZ...*)
	begin
	ISKPJMPA_OPCODE[S1OP] := XILLEGAL;
	DSKPJMPA_OPCODE[S1OP] := XILLEGAL
	end;

    ISKPJMPA_OPCODE [XJMPA]      := XIJMPA;
    ISKPJMPA_OPCODE [XSKP_EQL_S] := XISKP_EQL;
    ISKPJMPA_OPCODE [XSKP_NEQ_S] := XISKP_NEQ;
    ISKPJMPA_OPCODE [XSKP_GEQ_S] := XISKP_GEQ;
    ISKPJMPA_OPCODE [XSKP_LSS_S] := XISKP_LSS;
    ISKPJMPA_OPCODE [XSKP_GTR_S] := XISKP_GTR;
    ISKPJMPA_OPCODE [XSKP_LEQ_S] := XISKP_LEQ;

    DSKPJMPA_OPCODE [XJMPA]      := XDJMPA;
    DSKPJMPA_OPCODE [XSKP_EQL_S] := XDSKP_EQL;
    DSKPJMPA_OPCODE [XSKP_NEQ_S] := XDSKP_NEQ;
    DSKPJMPA_OPCODE [XSKP_GEQ_S] := XDSKP_GEQ;
    DSKPJMPA_OPCODE [XSKP_LSS_S] := XDSKP_LSS;
    DSKPJMPA_OPCODE [XSKP_GTR_S] := XDSKP_GTR;
    DSKPJMPA_OPCODE [XSKP_LEQ_S] := XDSKP_LEQ;			(*...28JUN79 PTZ*)

    for S1OP := FIRSTS1OP to LASTS1OP do
	begin
	case OPFORMAT[S1OP] of
	    VFAKEOP, VXOP :  N := 1;
	    VTOP :  N := TWOEXP[T_LEN];
	    VJOP :  N := TWOEXP[PR_LEN];
	    VSOP :  N := TWOEXP[SKP_LEN];
	    end (*case*);
	if not ( HARDOPCODE[S1OP] mod N = 0) then ASSERTFAIL('INITIALIZ001');
	for I := HARDOPCODE[S1OP] to (HARDOPCODE[S1OP]+N-1) do
	    SOFTOPCODE[I] := S1OP;
	end (*for S1OP := *);

    for S1OP := FIRSTS1OP to LASTS1OP do S1OP_CNT[S1OP] := 0;		(*LCW*)
    WORD_CNT := 0;							(*LCW*)

    INSTR_WDS_REMOVED := 0;						(*PTZ*)
    J_TO_J_CNT := 0;							(*PBK*)
    JMPAS_REMOVED_FROM_SKIPS := 0;					(*PTZ*)
    for ICNT := 1 to 14 do   MOV_COLLAPSE[ICNT] := 0;		(*21JUN79 PTZ*)
    MOVS_COLLAPSED := 0;						(*PTZ*)
    for ICNT := 1 to 3 do  INC_SKP_COLLAPSE[ICNT] := 0;		(*29JUN79 PTZ*)

    TR_PEEPHOLE := false;					(*15JAN79 PTZ*)
    TR_UCODE   := false;
    TR_S1CODE  := false;
    TR_STACK   := false;
    TR_MST     := false;
%   TR_NEST    := false;	\(* peg 18jul79*)
    TR_SIMP    := false;

    MAINCODE := EMPTYINSTLIST;					(*DATASTRCH*)
    NEWINSTREC := nil;

    BOT := 1;		(*STKINX of the first datum on STK*)(* peg 09jul79 *)
    TOP := BOT-1;
    CURFRAME := MINFRAME;				    (* peg 09jul79 *)
    STKFRAME[CURFRAME] := BOT;				    (* peg 09jul79 *)

    PREGS_ARCHIVED := false;				(* als/peg 18jul79 *)

    MSTTOP := 0;
    with MSTSTK[MSTTOP] do
	begin
	DESTLEV := 1;
	MSTCODESTART := nil;
	CURPARMREGS := 0;
	EVALSAVESTART := 0;
	end (*with MSTSTK[TOP] do*);

    DEBUG := false;
    ASM := false;
    ERRORCNT := 0;

    MAXLVLUSED := 0;

    TOTAL_STORAGE := 0;						(*31AUG79 PTZ...*)
    NUM_PROCS_COMPILED := 0;
    MAX_STORAGE := 0;						(*...31AUG79 PTZ*)

    ICUPSEEN := false;
    PSWITCHNAME := '$PSWITCH        ';
    end (*INIT6*);


(** INITIALIZE_CLASS:			INIT7 **)
(**)

    procedure INIT7;							(*PBK*)

	var	S1OP : S1OPCODE;

	begin

	(*Right now COLLAPSIBLE_OP[S1OP] = false iff DEST_PRECISION[S1OP]
	  = S1ILLEGAL. Someone ought to monitor this & remove COLLAPSIBLE_OP
	  if the situation persists for a long time. 9/24/78 PTZ*)
	(**** What the heck is this array for?? There are some 'new' opcodes
		-- should they be in this list?? -- als/peg 18jul79*)

	for S1OP := FIRSTS1OP to LASTS1OP do
	    COLLAPSIBLE_OP [S1OP] := false;

	COLLAPSIBLE_OP [XABS_Q] := true;
	COLLAPSIBLE_OP [XABS_H] := true;
	COLLAPSIBLE_OP [XABS_S] := true;
	COLLAPSIBLE_OP [XABS_D] := true;
	COLLAPSIBLE_OP [XADD_S] := true;
	COLLAPSIBLE_OP [XADD_D] := true;
	COLLAPSIBLE_OP [XAND_Q] := true;
	COLLAPSIBLE_OP [XAND_D] := true;
	COLLAPSIBLE_OP [XAND_TC_D] := true;
	COLLAPSIBLE_OP [XAND_CT_D] := true;
	COLLAPSIBLE_OP [XDEC_S]  := true;
	COLLAPSIBLE_OP [XFX_DM_S_S]  := true;
	COLLAPSIBLE_OP [XFX_DM_S_D]  := true;
	COLLAPSIBLE_OP [XFLOAT_S_Q] := true;
	COLLAPSIBLE_OP [XFLOAT_S_H] := true;
	COLLAPSIBLE_OP [XFLOAT_S_S] := true;
	COLLAPSIBLE_OP [XFLOAT_S_D] := true;
	COLLAPSIBLE_OP [XFADD_S]  := true;
	COLLAPSIBLE_OP [XFADD_D]  := true;
	COLLAPSIBLE_OP [XFSUB_S]  := true;
	COLLAPSIBLE_OP [XFSUBV_S] := true;
	COLLAPSIBLE_OP [XFSUB_D]  := true;
	COLLAPSIBLE_OP [XFSUBV_D] := true;
	COLLAPSIBLE_OP [XFMULT_S] := true;
	COLLAPSIBLE_OP [XFMULT_D] := true;
	COLLAPSIBLE_OP [XFDIV_S]  := true;
	COLLAPSIBLE_OP [XFDIVV_S] := true;
	COLLAPSIBLE_OP [XFDIV_D]  := true;
	COLLAPSIBLE_OP [XFDIVV_D] := true;
	COLLAPSIBLE_OP [XFTRANS_S_D] := true;
	COLLAPSIBLE_OP [XFTRANS_D_S] := true;
	COLLAPSIBLE_OP [XINC_S]	   := true;
	COLLAPSIBLE_OP [XMOV_A] := true;
	COLLAPSIBLE_OP [XMOV_Q_Q] := true;
	COLLAPSIBLE_OP [XMOV_Q_H] := true;
	COLLAPSIBLE_OP [XMOV_H_Q] := true;
	COLLAPSIBLE_OP [XMOV_H_H] := true;
	COLLAPSIBLE_OP [XMOV_Q_S] := true;
	COLLAPSIBLE_OP [XMOV_H_S] := true;
	COLLAPSIBLE_OP [XMOV_S_Q] := true;
	COLLAPSIBLE_OP [XMOV_S_H] := true;
	COLLAPSIBLE_OP [XMOV_S_S] := true;
	COLLAPSIBLE_OP [XMOV_Q_D] := true;
	COLLAPSIBLE_OP [XMOV_H_D] := true;
	COLLAPSIBLE_OP [XMOV_S_D] := true;
	COLLAPSIBLE_OP [XMOV_D_Q] := true;
	COLLAPSIBLE_OP [XMOV_D_H] := true;
	COLLAPSIBLE_OP [XMOV_D_S] := true;
	COLLAPSIBLE_OP [XMOV_D_D] := true;
	COLLAPSIBLE_OP [XMULT_S]  := true;
	COLLAPSIBLE_OP [XMULT_D]  := true;
	COLLAPSIBLE_OP [XNEG_Q] := true;
	COLLAPSIBLE_OP [XNEG_H] := true;
	COLLAPSIBLE_OP [XNEG_S] := true;
	COLLAPSIBLE_OP [XNEG_D] := true;
	COLLAPSIBLE_OP [XOR_Q]  := true;
	COLLAPSIBLE_OP [XOR_D]  := true;
	COLLAPSIBLE_OP [XQUO_S]  := true;
	COLLAPSIBLE_OP [XQUOV_S] := true;
	COLLAPSIBLE_OP [XQUO_D]  := true;
	COLLAPSIBLE_OP [XQUOV_D] := true;
	COLLAPSIBLE_OP [XREM_S]  := true;
	COLLAPSIBLE_OP [XREMV_S] := true;
	COLLAPSIBLE_OP [XREM_D]  := true;
	COLLAPSIBLE_OP [XREMV_D] := true;
	COLLAPSIBLE_OP [XSHF_LF_D]  := true;
	COLLAPSIBLE_OP [XSHFV_LF_D] := true;
	COLLAPSIBLE_OP [XSHFA_LF_S] := true;
	COLLAPSIBLE_OP [XSHFAV_LF_S] := true;
	COLLAPSIBLE_OP [XSUB_S]  := true;
	COLLAPSIBLE_OP [XSUBV_S] := true;
	COLLAPSIBLE_OP [XSUB_D]  := true;
	COLLAPSIBLE_OP [XSUBV_D] := true;
	COLLAPSIBLE_OP [XTRANS_Q_Q] := true;
	COLLAPSIBLE_OP [XTRANS_Q_H] := true;
	COLLAPSIBLE_OP [XTRANS_H_Q] := true;
	COLLAPSIBLE_OP [XTRANS_H_H] := true;
	COLLAPSIBLE_OP [XTRANS_Q_S] := true;
	COLLAPSIBLE_OP [XTRANS_H_S] := true;
	COLLAPSIBLE_OP [XTRANS_S_Q] := true;
	COLLAPSIBLE_OP [XTRANS_S_H] := true;
	COLLAPSIBLE_OP [XTRANS_S_S] := true;
	COLLAPSIBLE_OP [XTRANS_Q_D] := true;
	COLLAPSIBLE_OP [XTRANS_H_D] := true;
	COLLAPSIBLE_OP [XTRANS_S_D] := true;
	COLLAPSIBLE_OP [XTRANS_D_Q] := true;
	COLLAPSIBLE_OP [XTRANS_D_H] := true;
	COLLAPSIBLE_OP [XTRANS_D_S] := true;
	COLLAPSIBLE_OP [XTRANS_D_D] := true;
	COLLAPSIBLE_OP [XXOR_Q]  := true;
	     
	for S1OP := FIRSTS1OP to LASTS1OP do
	    DEST_PRECISION [S1OP] := S1ILLEGAL;

	DEST_PRECISION [XABS_Q] := S1Q;
	DEST_PRECISION [XABS_H] := S1H;
	DEST_PRECISION [XABS_S] := S1S;
	DEST_PRECISION [XABS_D] := S1D;
	DEST_PRECISION [XADD_S] := S1S;
	DEST_PRECISION [XADD_D] := S1D;
	DEST_PRECISION [XAND_Q] := S1Q;
	DEST_PRECISION [XAND_D] := S1D;
	DEST_PRECISION [XAND_TC_D] := S1D;
	DEST_PRECISION [XAND_CT_D] := S1D;
	DEST_PRECISION [XDEC_S]  := S1S;
	DEST_PRECISION [XFX_DM_S_S]  := S1S;
	DEST_PRECISION [XFX_DM_S_D]  := S1S;
	DEST_PRECISION [XFLOAT_S_Q] := S1S;
	DEST_PRECISION [XFLOAT_S_H] := S1S;
	DEST_PRECISION [XFLOAT_S_S] := S1S;
	DEST_PRECISION [XFLOAT_S_D] := S1S;
	DEST_PRECISION [XFADD_S]  := S1S;
	DEST_PRECISION [XFADD_D]  := S1D;
	DEST_PRECISION [XFSUB_S]  := S1S;
	DEST_PRECISION [XFSUBV_S] := S1S;
	DEST_PRECISION [XFSUB_D]  := S1D;
	DEST_PRECISION [XFSUBV_D] := S1D;
	DEST_PRECISION [XFMULT_S] := S1S;
	DEST_PRECISION [XFMULT_D] := S1D;
	DEST_PRECISION [XFDIV_S]  := S1S;
	DEST_PRECISION [XFDIVV_S] := S1S;
	DEST_PRECISION [XFDIV_D]  := S1D;
	DEST_PRECISION [XFDIVV_D] := S1D;
	DEST_PRECISION [XFTRANS_S_D] := S1S;
	DEST_PRECISION [XFTRANS_D_S] := S1D;
	DEST_PRECISION [XINC_S]	   := S1S;
	DEST_PRECISION [XMOV_A] := S1S;
	DEST_PRECISION [XMOV_Q_Q] := S1Q;
	DEST_PRECISION [XMOV_Q_H] := S1Q;
	DEST_PRECISION [XMOV_H_Q] := S1H;
	DEST_PRECISION [XMOV_H_H] := S1H;
	DEST_PRECISION [XMOV_Q_S] := S1Q;
	DEST_PRECISION [XMOV_H_S] := S1H;
	DEST_PRECISION [XMOV_S_Q] := S1S;
	DEST_PRECISION [XMOV_S_H] := S1S;
	DEST_PRECISION [XMOV_S_S] := S1S;
	DEST_PRECISION [XMOV_Q_D] := S1Q;
	DEST_PRECISION [XMOV_H_D] := S1H;
	DEST_PRECISION [XMOV_S_D] := S1S;
	DEST_PRECISION [XMOV_D_Q] := S1D;
	DEST_PRECISION [XMOV_D_H] := S1D;
	DEST_PRECISION [XMOV_D_S] := S1D;
	DEST_PRECISION [XMOV_D_D] := S1D;
	DEST_PRECISION [XMULT_S]  := S1S;
	DEST_PRECISION [XMULT_D]  := S1D;
	DEST_PRECISION [XDIV_S] := S1S;		(* als/peg 18jul79 *)
	DEST_PRECISION [XNEG_Q] := S1Q;
	DEST_PRECISION [XNEG_H] := S1H;
	DEST_PRECISION [XNEG_S] := S1S;
	DEST_PRECISION [XNEG_D] := S1D;
	DEST_PRECISION [XOR_Q]  := S1Q;
	DEST_PRECISION [XOR_D]  := S1D;
	DEST_PRECISION [XQUO_S]  := S1S;
	DEST_PRECISION [XQUOV_S] := S1S;
	DEST_PRECISION [XQUO_D]  := S1D;
	DEST_PRECISION [XQUOV_D] := S1D;
	DEST_PRECISION [XREM_S]  := S1S;
	DEST_PRECISION [XREMV_S] := S1S;
	DEST_PRECISION [XREM_D]  := S1D;
	DEST_PRECISION [XREMV_D] := S1D;
	DEST_PRECISION [XSHF_LF_D]  := S1D;
	DEST_PRECISION [XSHFV_LF_D] := S1D;
	DEST_PRECISION [XSHFA_LF_S] := S1S;
	DEST_PRECISION [XSHFAV_LF_S] := S1S;
	DEST_PRECISION [XSUB_S]  := S1S;
	DEST_PRECISION [XSUBV_S] := S1S;
	DEST_PRECISION [XSUB_D]  := S1D;
	DEST_PRECISION [XSUBV_D] := S1D;
	DEST_PRECISION [XTRANS_Q_Q] := S1Q;
	DEST_PRECISION [XTRANS_Q_H] := S1Q;
	DEST_PRECISION [XTRANS_H_Q] := S1H;
	DEST_PRECISION [XTRANS_H_H] := S1H;
	DEST_PRECISION [XTRANS_Q_S] := S1Q;
	DEST_PRECISION [XTRANS_H_S] := S1H;
	DEST_PRECISION [XTRANS_S_Q] := S1S;
	DEST_PRECISION [XTRANS_S_H] := S1S;
	DEST_PRECISION [XTRANS_S_S] := S1S;
	DEST_PRECISION [XTRANS_Q_D] := S1Q;
	DEST_PRECISION [XTRANS_H_D] := S1H;
	DEST_PRECISION [XTRANS_S_D] := S1S;
	DEST_PRECISION [XTRANS_D_Q] := S1D;
	DEST_PRECISION [XTRANS_D_H] := S1D;
	DEST_PRECISION [XTRANS_D_S] := S1D;
	DEST_PRECISION [XTRANS_D_D] := S1D;
	DEST_PRECISION [XXOR_Q]  := S1Q;
	     
	end (*INIT7*);

(** INITIALIZE_CLASS:			 **)
(**)

    begin (*INITIALIZE*)
    INIT1;
    INIT2;
    INIT3;
    INIT4;
    INIT5;
    INIT6;
    INIT7;								(*PBK*)
    end (*INITIALIZE*);

(** MAIN_PROGRAM:			**)
(**)

begin  (*Main Program.*)

ASSERTCOUNT := 0;
INITIALIZE;
(*%IFT D10*)
TIMER := CLOCK; 
(*%ELSE*)
%  TIMER := CLOCK(1);	\
(*%ENDC*)

repeat
    OLDINSTREC := NEWINSTREC;
    OLDTOP := TOP;
    OLDMSTTOP := MSTTOP;

    READNXTINST;
    if TR_UCODE then PRINTNXTINST;				
    ASMNXTINST;

    if TR_S1CODE and (OLDINSTREC <> NEWINSTREC) then
	begin
	WRITELN (OUTPUT, '      Instruction(s) emitted:');
	if OLDINSTREC = nil then
	    OLDINSTREC := MAINCODE.FIRST;
	while OLDINSTREC <> nil do
	    begin
	    UNKNOWN_LOC := 0;
  	    DISASSEMBLE (UNKNOWN_LOC, OLDINSTREC); 
	    OLDINSTREC := OLDINSTREC↑.NEXTPTR;			(*DATASTRCH*)
	    end;
	end;
    if TR_STACK then
	begin
	if OLDTOP < TOP then
	    WRITELN (OUTPUT, '      Stack pushed. New top is ',
			     TOP : FLDW(TOP) )
	else if OLDTOP > TOP then
	    WRITELN (OUTPUT, '      Stack popped.  New top is ',
			     TOP : FLDW(TOP) )
	else if TOP >= BOT then
	    WRITELN (OUTPUT, '      Stack top is ')
	else
	    WRITELN (OUTPUT, '      Stack is empty.');
  	if TOP >= BOT then PRINTDATUM (TOP);
	end;
    if TR_MST and (MSTTOP <> OLDMSTTOP) then
	begin
	if OLDMSTTOP < MSTTOP then
	    WRITELN (OUTPUT, ' MST stack pushed. New top is ',
			     MSTTOP : FLDW(MSTTOP) )
	else if OLDMSTTOP > MSTTOP then
	    WRITELN (OUTPUT, ' MST stack popped.  New top is ',
			     MSTTOP : FLDW(MSTTOP) );
	PRINT_MSTENTRY (MSTTOP);
	end;
until OPC = USTP;
if ICUPSEEN then GEN_PSWITCH;

if not ASM then							(*12AUG79 EJG*)
	WRITE(OUTPUT,chr(12));	(*12 dec = 14 oct = FF (form feed) *)
WRITELN (OUTPUT,'**************************  ;START OF STATISTICS');	(*LCW*)
WRITELN (OUTPUT,'**************************  ;WRITER-ID: ',
	       SOPA_ID); 	                                (*23JUL79 PTZ*)

WRITELN (OUTPUT);							(*PBK*)
WRITELN (OUTPUT,' PEEPHOLE OPTIMIZER STATISTICS:');			(*PBK*)
WRITELN (OUTPUT);							(*PBK*)
WRITELN (OUTPUT,' ',J_TO_J_CNT:7,' JMPAS CHAINED');			(*PBK*)
WRITELN (OUTPUT,' ',JMPAS_REMOVED_FROM_SKIPS:7,' JMPAS REMOVED FROM SKIPS');(*PTZ*)

MOVS_COLLAPSED := 0;						(*31AUG79 PTZ...*)
for ICNT := 1 to 14 do
    MOVS_COLLAPSED := MOVS_COLLAPSED + MOV_COLLAPSE[ICNT];
WRITELN (OUTPUT,' ',MOVS_COLLAPSED:7,' OP-MOVS COLLAPSED');
WRITE (OUTPUT,'(':10);
for ICNT := 1 to 7 do
    WRITE (OUTPUT,MOV_COLLAPSE[ICNT]:7,'  ');
WRITELN (OUTPUT,')');
WRITE (OUTPUT,'(':10);
for ICNT := 8 to 14 do
    WRITE (OUTPUT,MOV_COLLAPSE[ICNT]:7,'  ');
WRITELN (OUTPUT,')');

INC_SKPS_COLLAPSED := 0;
for ICNT := 1 to 3 do
    INC_SKPS_COLLAPSED := INC_SKPS_COLLAPSED + INC_SKP_COLLAPSE[ICNT];
WRITELN (OUTPUT,' ',INC_SKPS_COLLAPSED:7,' INC-SKPS COLLAPSED');
WRITE (OUTPUT,'(':10);
for ICNT := 1 to 3 do
    WRITE (OUTPUT,INC_SKP_COLLAPSE[ICNT]:7,'  ');
WRITELN (OUTPUT,')');						(*...31AUG79 PTZ*)

WRITELN (OUTPUT);
WRITELN (OUTPUT,' ',INSTR_WDS_REMOVED:7,' TOTAL WORDS REMOVED');	(*PTZ*)
WRITELN (OUTPUT);						(*22JUN79 PTZ*)

WRITELN (OUTPUT,' INSTRUCTION COUNTS:');				(*LCW*)
WRITELN (OUTPUT);							(*LCW*)
S1OP_TOT := 0;								(*LCW*)
for S1OP := FIRSTS1OP to LASTS1OP do					(*LCW*)
     begin								(*LCW*)
     if OPFORMAT[S1OP] <> VFAKEOP then                          (*21JUN79 PTZ*)
	 S1OP_TOT := S1OP_TOT + S1OP_CNT[S1OP];                 (*21JUN79 PTZ*)
     if S1OP_CNT[S1OP] <> 0						(*LCW*)
       then WRITELN (OUTPUT,' ',S1OP_CNT[S1OP]:7,' ',S1MNEM[S1OP]);	(*LCW*)
     end;								(*LCW*)
WRITELN (OUTPUT);							(*LCW*)
WRITELN (OUTPUT,' ',S1OP_TOT:7,' TOTAL REAL INSTRUCTIONS');	(*21JUN79 PTZ*)

WRITELN (OUTPUT);							(*LCW*)
WRITELN (OUTPUT,' ',WORD_CNT:7,' TXT WORDS OUTPUT TO LOADER FILE');	(*LCW*)

WRITELN (OUTPUT);						(*31AUG79 PTZ...*)
WRITELN (OUTPUT,' COMPILATION STATISTICS:');
WRITELN (OUTPUT);
WRITELN (OUTPUT,' ',NUM_PROCS_COMPILED:10,' PROCEDURES COMPILED');
(*%IFT D10*)
WRITELN (OUTPUT,' ',TOTAL_STORAGE div NUM_PROCS_COMPILED:10,
	 ' AVERAGE HEAP SPACE USED PER PROCEDURE (WORDS)');
WRITELN (OUTPUT,' ',MAX_STORAGE:10,' MAXIMUM HEAP SPACE USED (WORDS)');
(*%ELSE*)
%WRITELN (OUTPUT,' ',TOTAL_STORAGE div (NUM_PROCS_COMPILED*WORDUNITS):10, \
%	 ' AVERAGE HEAP SPACE USED PER PROCEDURE (WORDS)'); \
%WRITELN (OUTPUT,' ',MAX_STORAGE div WORDUNITS:10, \
%	 ' MAXIMUM HEAP SPACE USED (WORDS)'); \
(*%ENDC*)							(*...31AUG79 PTZ*)

WRITELN(OUTPUT);
WRITE (OUTPUT, ' ****   ');
if ERRORCNT > 0 then  WRITE (OUTPUT, ERRORCNT : 5)
		else  WRITE (OUTPUT, 'NO' : 5);
WRITELN (OUTPUT, ' ASSEMBLY ERROR(S) DETECTED');		(*31AUG79 PTZ...*)

(*%IFT D10 *)
TIMER := ( CLOCK - TIMER ) div 10;	
(*%ELSE*)
%  TIMER := ( CLOCK(1) - TIMER ) div 10;	\
(*%ENDC*)

WRITELN (OUTPUT,' **** ',TIMER div 100 : 4, '.', TIMER mod 100 : 2,
   ' SECONDS in U-CODE ASSEMBLY' );				(*...31AUG79 PTZ*)

if ERRORCNT <> 0 then ERREXIT (ERRORCNT);

end  (*Main Program*).