usr/src/old/as.vax/ascode.c

/* Copyright (c) 1980 Regents of the University of California */
static	char sccsid[] = "@(#)ascode.c 4.7 %G%";
#include <stdio.h>
#include "as.h"
#include "assyms.h"

/*
 *	Loader reference types  (plust PCREL) to bytes and lg bytes
 */
/*		LEN1	LEN1+PC	LEN2	LEN2+PC	LEN4	LEN4+PC	LEN8	LEN8+PC*/
int	reflen[] = 	/* {LEN*+PCREL} ==> number of bytes */
{0,	0,	1,	1,	2,	2,	4,	4,	8,	8};
int	lgreflen[] =	/* {LEN*+PCREL} ==> lg number of bytes */
{-1,	-1,	0,	0,	1,	1,	2,	2,	3,	3};

/*
 *	Sizes to Loader reference types and type flags
 */
/*0	1	2	3	4	5	6	7	8*/
int	len124[] = 	/* {1,2,4,8} ==> {LEN1, LEN2, LEN4, LEN8} */
{0,	LEN1,	LEN2,	0,	LEN4,	0,	0,	0,	LEN8};
char	mod124[] = 	/* {1,2,4,8} ==> {bits to construct operands */
{0,	0x00,	0x20,	0,	0x40,	0,	0,	0,	0};
int	type_124[] =	/* {1,2,4,8} ==> {TYPB, TYPW, TYPL, TYPQ} */
{0,	 TYPB,	TYPW,	 0,	 TYPL,	 0,	 0,	 0,	 TYPQ};

/*
 *	type flags to Loader reference and byte lengths
 */
/*TYPB	TYPW	TYPL	TYPQ	TYPF	TYPD*/
int	ty_NORELOC[] =	/* {TYPB..TYPD} ==> {1 if relocation not OK */
{0,	0,	0,	1,	1,	1};
int	ty_LEN[] =	/* {TYPB..TYPD} ==> {LEN1..LEN8} */
{LEN1,	LEN2,	LEN4,	LEN8,	LEN4,	LEN8};
int	ty_nbyte[] =	/* {TYPB..TYPD} ==> {1,2,4,8} */
{1,	2,	4,	8,	4,	8};
int	ty_nlg[] =	/* {TYPB..TYPD} ==> lg{1,2,4,8} */
{0,	1,	2,	3,	2,	3};

insout(op, ap, nact)
	struct arg *ap;
{
	int		jxxflg;
	register	struct	instab	*ip;		/* the instruction */
	register	struct	arg	*ap_walk;	/* actual param walk */
	register	int	i;
	register	int	ap_type;		/* actual param type */
	register	int	ap_type_mask;		/* masked actual param */
	op &= 0xFF;
	jxxflg = nact;
	if (nact < 0)
		nact = -nact;
	if (passno == 1) {
	    ip = itab[op];
	    if (nact < ip->i_nargs)
		yyerror("Too few arguments");
	    if (nact > ip->i_nargs) {
		yyerror("Too many arguments");
		nact = ip->i_nargs;
	    }
	    /*
	     *	Check argument compatability with instruction template
	     */
	    for (ap_walk = ap, i = 1; i <= nact; ap_walk++, i++){
		ap_type = ap_walk->a_atype;
		ap_type_mask = ap_type & AMASK;
		/*
		 *	The switch value is >> by 3 so that the switch
		 *	code is dense, not implemented as a sequence
		 *	of branches but implemented as a casel.
		 *	In addition, cases ACCI and ACCR are added to force
		 *	dense switch code.
		 */
		switch( ((fetcharg(ip, i-1)) & ACCESSMASK)>>3){	/* type of fp */
		case ACCI >> 3:
		case ACCR >> 3:
			break;
		case ACCB >> 3:
			if ( !((ap_type_mask == AEXP) || (ap_type_mask == AIMM)) ){
				yyerror("arg %d, branch displacement must be an expression",i);
				return;
			}
			break;
		case ACCA >> 3:
			switch(ap_type_mask){
			case AREG:	yyerror("arg %d, addressing a register",i);
					return;
			case AIMM:	if ( !(ap_type & ASTAR) ){
					 yyerror("arg %d, addressing an immediate operand",i);
					 return;
					}
			}
			break;
		case ACCM >> 3:
		case ACCW >> 3:
			switch(ap_type_mask){
			case AIMM:	if (!(ap_type&ASTAR)) {
					 yyerror("arg %d, modifying a constant",i);
					 return;
					}
			}
			break;
		}	/* end of the switch on fp_type */
		if (ap_type & AINDX) {
			if (ap_walk->a_areg2==0xF) {
				yyerror("arg %d, PC used as index",i);
				return;
			}
			switch(ap_type_mask){
			case AREG:	yyerror("arg %d, indexing the register file",i);
					return;
			case AIMM:	yyerror("arg %d, indexing a constant",i);
					return;
			case ADECR:
			case AINCR:	if (ap_walk->a_areg1==ap_walk->a_areg2) {
						yyerror("arg %d, indexing with modified register",i);
						return;
					}
					break;
			}	/* end of switch on ap_type_mask */
		} /* end of AINDX */
	   }
	} /* both passes here */
	if (jxxflg < 0)
		ijxout(op, ap, nact);
	else putins(op, ap, nact);
}

extern	int d124;

putins(op, ap, n)
	/*
	 *	n had better be positive
	 */
	register struct arg *ap;
{
	register struct exp 	*xp;
	register int 		argtype;
	int 			i;
	int			reloc_how;

#ifdef DEBUG
	fflush(stdout);
#endif
	if (passno == 2)
		goto PASS2;

	dotp->e_xvalue += n+1;		/* 1 for the opcode, at least 1 per arg */
	for (i=0; i<n; i++,ap++) {	/* some args take more than 1 byte */
	    argtype = ap->a_atype;
	    if (argtype & AINDX)
		dotp->e_xvalue++;
	    /*
	     *	This switch has been fixed by enumerating the no action
	     *	alternatives (those that have 1 one byte of code)
	     *	so that a casel instruction is emitted.
	     */
	    switch (argtype&~(AINDX|ASTAR)) {
		case AREG:
		case ABASE:
		case ADECR:
		case AINCR:
			break;
		case AEXP:
			argtype = fetcharg(itab[op], i);
			if (argtype == ACCB+TYPB)
				break;
			if (argtype==ACCB+TYPW){
				dotp->e_xvalue++;
				break;
			}
			/*
			 *	Reduces to PC relative
			 */
			dotp->e_xvalue += ap->a_dispsize;
			break;

		case ADISP:
			xp=ap->a_xp;
			if ((xp->e_xtype&XTYPE)!=XABS || xp->e_xtype&XFORW){
				dotp->e_xvalue += ap->a_dispsize;
				break;
			}
			if (xp->e_xvalue==0 && !(argtype&ASTAR))
				break;
			dotp->e_xvalue++;
			if ((xp->e_xvalue<MINBYTE) || (xp->e_xvalue>MAXBYTE))
				dotp->e_xvalue++;
			if ((xp->e_xvalue<MINWORD) || (xp->e_xvalue>MAXWORD))
				dotp->e_xvalue += 2;
			break;

		case AIMM:
			if (ap->a_atype&ASTAR) argtype=TYPL;
			else {
				argtype = fetcharg(itab[op], i);
				if (argtype&ACCA)
					argtype = TYPL;
				else
					argtype &= TYPMASK;
				xp = ap->a_xp;
				if (   ((xp->e_xtype&XTYPE)==XABS)
				    && (!(xp->e_xtype&XFORW))
				    && (xp->e_xvalue>=0)
				    && (xp->e_xvalue<=63)
				    && (xp->e_yvalue == 0)
				    && (argtype != TYPD)
				    && (argtype != TYPF)
				)
						break;
			}
			switch (argtype) {
			case TYPD:
			case TYPF:
				if (   !(((xp->e_xtype&XTYPE)==XABS)
				    && (!(xp->e_xtype&XFORW))
				    && (slitflt(xp)))
				){
				/* it is NOT short */
					dotp->e_xvalue += ((argtype==TYPF)?
						4 : 8);
				}
				break;
			case TYPQ:
				dotp->e_xvalue += 8;break;
			case TYPL:
				dotp->e_xvalue += 4;break;
			case TYPW:
				dotp->e_xvalue += 2;break;
			case TYPB:
				dotp->e_xvalue += 1;break;
			}	/*end of the switch on argtype*/
	    }	/*end of the switch on the type*/
	}	/*end of looping for all arguments*/
	return;

PASS2:

#ifdef UNIX
	outb(op); /* the opcode */
#endif UNIX
#ifdef VMS
	*vms_obj_ptr++ = -1; *vms_obj_ptr++ = (char)op;
	dotp->e_xvalue += 1;
#endif VMS

	for (i=0; i<n; i++,ap++) {/* now for the arguments */
		argtype=ap->a_atype;
		xp=ap->a_xp;
		reloc_how = TYPNONE;
		if (argtype&AINDX) {
#ifdef UNIX
			{ outb(0x40 | ap->a_areg2); }
#endif UNIX
#ifdef VMS
			{ *vms_obj_ptr++ = -1;
			  *vms_obj_ptr++ = (0x40 | ap->a_areg2);
			  dotp->e_xvalue += 1; }
#endif VMS
			argtype &= ~AINDX;
		}
		if (argtype&ASTAR) {
			ap->a_areg1 |= 0x10;
			argtype &= ~ASTAR;
		}
		switch (argtype) {
		case AREG:		/* %r */
			ap->a_areg1 |= 0x50;
			break;
		case ABASE:		/* (%r) */
			ap->a_areg1 |= 0x60;
			break;
		case ADECR: 		/* -(%r) */
			ap->a_areg1 |= 0x70;
			break;
		case AINCR:		/* (%r)+ */
			ap->a_areg1 |= 0x80;
			break;
		case AEXP: /* expr */
			argtype = fetcharg(itab[op], i);
			if (argtype == ACCB+TYPB) {
				ap->a_areg1 = argtype =
					xp->e_xvalue - (dotp->e_xvalue + 1);
				if (argtype<MINBYTE || argtype>MAXBYTE)
					yyerror("Branch too far"); break;
			}
			if (argtype == ACCB+TYPW) {
				ap->a_areg1 = argtype = xp->e_xvalue
					-= dotp->e_xvalue + 2;
				xp->e_xtype = XABS;
				if (argtype<MINWORD || argtype>MAXWORD)
					yyerror("Branch too far");
				xp->e_xvalue = argtype>>8;
				reloc_how = TYPB;
				break;
			}
			/* reduces to expr(pc) mode */
			ap->a_areg1 |= (0xAF + mod124[ap->a_dispsize]);
			reloc_how = type_124[ap->a_dispsize] + RELOC_PCREL;
			break;

		case ADISP: /* expr(%r) */
			ap->a_areg1 |= 0xA0;
			if ((xp->e_xtype&XTYPE)!=XABS || xp->e_xtype&XFORW){
				ap->a_areg1 += mod124[ap->a_dispsize];
				reloc_how = type_124[ap->a_dispsize];
				break;
			}
			if (xp->e_xvalue==0 && !(ap->a_areg1&0x10)) {
				ap->a_areg1 ^= 0xC0;
				break;
			}
			reloc_how = TYPB;
			if ((xp->e_xvalue<MINBYTE) || (xp->e_xvalue>MAXBYTE)){
				ap->a_areg1 += 0x20;
				reloc_how = TYPW;
			}
			if ((xp->e_xvalue<MINWORD) || (xp->e_xvalue>MAXWORD)){
				ap->a_areg1 += 0x20;
				reloc_how = TYPL;
			}
			break;

		case AIMM:  /* $expr */
			if (ap->a_atype&ASTAR)
				argtype=TYPL;
			else {
				argtype = fetcharg(itab[op], i);
				if (argtype&ACCA)
					argtype=TYPL;
				else
					argtype &= TYPMASK;
				if (    ( (xp->e_xtype&XTYPE) == XABS)
				    && !(xp->e_xtype&XFORW)
				    &&  (xp->e_xvalue >= 0)
				    &&  (xp->e_xvalue <= 63)
				    &&  (xp->e_yvalue == 0)
				    &&  (argtype != TYPF)
				    &&  (argtype != TYPD) ) {
					ap->a_areg1 = xp->e_xvalue;
					break;
				}
			}
			ap->a_areg1 |= 0x8F;
			reloc_how = argtype;
			if (reloc_how == TYPD || reloc_how == TYPF){
				if (   ((xp->e_xtype&XTYPE)==XABS)
				    && (!(xp->e_xtype&XFORW))
				    && (slitflt(xp))
				){
					reloc_how = TYPNONE;
					ap->a_areg1=extlitflt(xp);
				}
			}
			break;

		}	/*end of the switch on argtype*/
		/*
		 *	use the first byte to describe the argument
		 */
#ifdef UNIX
		outb(ap->a_areg1);
#endif UNIX
#ifdef VMS
		*vms_obj_ptr++ = -1; *vms_obj_ptr++ = (char)(ap->a_areg1);
		dotp->e_xvalue += 1;
		if ((vms_obj_ptr-sobuf) > 400) {
			write(objfil,sobuf,vms_obj_ptr-sobuf);
			vms_obj_ptr=sobuf+1;
		}
#endif VMS
		if (reloc_how != TYPNONE)
			outrel(xp, reloc_how);
	}	/*end of the for to pick up all arguments*/
}
Commit	Line	Data
	1	/* Copyright (c) 1980 Regents of the University of California */
	2	static char sccsid[] = "@(#)ascode.c 4.7 %G%";
	3	#include <stdio.h>
	4	#include "as.h"
	5	#include "assyms.h"
	6
	7	/*
	8	* Loader reference types (plust PCREL) to bytes and lg bytes
	9	*/
	10	/* LEN1 LEN1+PC LEN2 LEN2+PC LEN4 LEN4+PC LEN8 LEN8+PC*/
	11	int reflen[] = /* {LEN+PCREL} ==> number of bytes /
	12	{0, 0, 1, 1, 2, 2, 4, 4, 8, 8};
	13	int lgreflen[] = /* {LEN+PCREL} ==> lg number of bytes /
	14	{-1, -1, 0, 0, 1, 1, 2, 2, 3, 3};
	15
	16	/*
	17	* Sizes to Loader reference types and type flags
	18	*/
	19	/0 1 2 3 4 5 6 7 8/
	20	int len124[] = /* {1,2,4,8} ==> {LEN1, LEN2, LEN4, LEN8} */
	21	{0, LEN1, LEN2, 0, LEN4, 0, 0, 0, LEN8};
	22	char mod124[] = /* {1,2,4,8} ==> {bits to construct operands */
	23	{0, 0x00, 0x20, 0, 0x40, 0, 0, 0, 0};
	24	int type_124[] = /* {1,2,4,8} ==> {TYPB, TYPW, TYPL, TYPQ} */
	25	{0, TYPB, TYPW, 0, TYPL, 0, 0, 0, TYPQ};
	26
	27	/*
	28	* type flags to Loader reference and byte lengths
	29	*/
	30	/TYPB TYPW TYPL TYPQ TYPF TYPD/
	31	int ty_NORELOC[] = /* {TYPB..TYPD} ==> {1 if relocation not OK */
	32	{0, 0, 0, 1, 1, 1};
	33	int ty_LEN[] = /* {TYPB..TYPD} ==> {LEN1..LEN8} */
	34	{LEN1, LEN2, LEN4, LEN8, LEN4, LEN8};
	35	int ty_nbyte[] = /* {TYPB..TYPD} ==> {1,2,4,8} */
	36	{1, 2, 4, 8, 4, 8};
	37	int ty_nlg[] = /* {TYPB..TYPD} ==> lg{1,2,4,8} */
	38	{0, 1, 2, 3, 2, 3};
	39
	40	insout(op, ap, nact)
	41	struct arg *ap;
	42	{
	43	int jxxflg;
	44	register struct instab ip; / the instruction */
	45	register struct arg ap_walk; / actual param walk */
	46	register int i;
	47	register int ap_type; /* actual param type */
	48	register int ap_type_mask; /* masked actual param */
	49	op &= 0xFF;
	50	jxxflg = nact;
	51	if (nact < 0)
	52	nact = -nact;
	53	if (passno == 1) {
	54	ip = itab[op];
	55	if (nact < ip->i_nargs)
	56	yyerror("Too few arguments");
	57	if (nact > ip->i_nargs) {
	58	yyerror("Too many arguments");
	59	nact = ip->i_nargs;
	60	}
	61	/*
	62	* Check argument compatability with instruction template
	63	*/
	64	for (ap_walk = ap, i = 1; i <= nact; ap_walk++, i++){
	65	ap_type = ap_walk->a_atype;
	66	ap_type_mask = ap_type & AMASK;
	67	/*
	68	* The switch value is >> by 3 so that the switch
	69	* code is dense, not implemented as a sequence
	70	* of branches but implemented as a casel.
	71	* In addition, cases ACCI and ACCR are added to force
	72	* dense switch code.
	73	*/
	74	switch( ((fetcharg(ip, i-1)) & ACCESSMASK)>>3){ /* type of fp */
	75	case ACCI >> 3:
	76	case ACCR >> 3:
	77	break;
	78	case ACCB >> 3:
	79	if ( !((ap_type_mask == AEXP) \|\| (ap_type_mask == AIMM)) ){
	80	yyerror("arg %d, branch displacement must be an expression",i);
	81	return;
	82	}
	83	break;
	84	case ACCA >> 3:
	85	switch(ap_type_mask){
	86	case AREG: yyerror("arg %d, addressing a register",i);
	87	return;
	88	case AIMM: if ( !(ap_type & ASTAR) ){
	89	yyerror("arg %d, addressing an immediate operand",i);
	90	return;
	91	}
	92	}
	93	break;
	94	case ACCM >> 3:
	95	case ACCW >> 3:
	96	switch(ap_type_mask){
	97	case AIMM: if (!(ap_type&ASTAR)) {
	98	yyerror("arg %d, modifying a constant",i);
	99	return;
	100	}
	101	}
	102	break;
	103	} /* end of the switch on fp_type */
	104	if (ap_type & AINDX) {
	105	if (ap_walk->a_areg2==0xF) {
	106	yyerror("arg %d, PC used as index",i);
	107	return;
	108	}
	109	switch(ap_type_mask){
	110	case AREG: yyerror("arg %d, indexing the register file",i);
	111	return;
	112	case AIMM: yyerror("arg %d, indexing a constant",i);
	113	return;
	114	case ADECR:
	115	case AINCR: if (ap_walk->a_areg1==ap_walk->a_areg2) {
	116	yyerror("arg %d, indexing with modified register",i);
	117	return;
	118	}
	119	break;
	120	} /* end of switch on ap_type_mask */
	121	} /* end of AINDX */
	122	}
	123	} /* both passes here */
	124	if (jxxflg < 0)
	125	ijxout(op, ap, nact);
	126	else putins(op, ap, nact);
	127	}
	128
	129	extern int d124;
	130
	131	putins(op, ap, n)
	132	/*
	133	* n had better be positive
	134	*/
	135	register struct arg *ap;
	136	{
	137	register struct exp *xp;
	138	register int argtype;
	139	int i;
	140	int reloc_how;
	141
	142	#ifdef DEBUG
	143	fflush(stdout);
	144	#endif
	145	if (passno == 2)
	146	goto PASS2;
	147
	148	dotp->e_xvalue += n+1; /* 1 for the opcode, at least 1 per arg */
	149	for (i=0; i<n; i++,ap++) { /* some args take more than 1 byte */
	150	argtype = ap->a_atype;
	151	if (argtype & AINDX)
	152	dotp->e_xvalue++;
	153	/*
	154	* This switch has been fixed by enumerating the no action
	155	* alternatives (those that have 1 one byte of code)
	156	* so that a casel instruction is emitted.
	157	*/
	158	switch (argtype&~(AINDX\|ASTAR)) {
	159	case AREG:
	160	case ABASE:
	161	case ADECR:
	162	case AINCR:
	163	break;
	164	case AEXP:
	165	argtype = fetcharg(itab[op], i);
	166	if (argtype == ACCB+TYPB)
	167	break;
	168	if (argtype==ACCB+TYPW){
	169	dotp->e_xvalue++;
	170	break;
	171	}
	172	/*
	173	* Reduces to PC relative
	174	*/
	175	dotp->e_xvalue += ap->a_dispsize;
	176	break;
	177
	178	case ADISP:
	179	xp=ap->a_xp;
	180	if ((xp->e_xtype&XTYPE)!=XABS \|\| xp->e_xtype&XFORW){
	181	dotp->e_xvalue += ap->a_dispsize;
	182	break;
	183	}
	184	if (xp->e_xvalue==0 && !(argtype&ASTAR))
	185	break;
	186	dotp->e_xvalue++;
	187	if ((xp->e_xvalue<MINBYTE) \|\| (xp->e_xvalue>MAXBYTE))
	188	dotp->e_xvalue++;
	189	if ((xp->e_xvalue<MINWORD) \|\| (xp->e_xvalue>MAXWORD))
	190	dotp->e_xvalue += 2;
	191	break;
	192
	193	case AIMM:
	194	if (ap->a_atype&ASTAR) argtype=TYPL;
	195	else {
	196	argtype = fetcharg(itab[op], i);
	197	if (argtype&ACCA)
	198	argtype = TYPL;
	199	else
	200	argtype &= TYPMASK;
	201	xp = ap->a_xp;
	202	if ( ((xp->e_xtype&XTYPE)==XABS)
	203	&& (!(xp->e_xtype&XFORW))
	204	&& (xp->e_xvalue>=0)
	205	&& (xp->e_xvalue<=63)
	206	&& (xp->e_yvalue == 0)
	207	&& (argtype != TYPD)
	208	&& (argtype != TYPF)
	209	)
	210	break;
	211	}
	212	switch (argtype) {
	213	case TYPD:
	214	case TYPF:
	215	if ( !(((xp->e_xtype&XTYPE)==XABS)
	216	&& (!(xp->e_xtype&XFORW))
	217	&& (slitflt(xp)))
	218	){
	219	/* it is NOT short */
	220	dotp->e_xvalue += ((argtype==TYPF)?
	221	4 : 8);
	222	}
	223	break;
	224	case TYPQ:
	225	dotp->e_xvalue += 8;break;
	226	case TYPL:
	227	dotp->e_xvalue += 4;break;
	228	case TYPW:
	229	dotp->e_xvalue += 2;break;
	230	case TYPB:
	231	dotp->e_xvalue += 1;break;
	232	} /end of the switch on argtype/
	233	} /end of the switch on the type/
	234	} /end of looping for all arguments/
	235	return;
	236
	237	PASS2:
	238
	239	#ifdef UNIX
	240	outb(op); /* the opcode */
	241	#endif UNIX
	242	#ifdef VMS
	243	vms_obj_ptr++ = -1; vms_obj_ptr++ = (char)op;
	244	dotp->e_xvalue += 1;
	245	#endif VMS
	246
	247	for (i=0; i<n; i++,ap++) {/* now for the arguments */
	248	argtype=ap->a_atype;
	249	xp=ap->a_xp;
	250	reloc_how = TYPNONE;
	251	if (argtype&AINDX) {
	252	#ifdef UNIX
	253	{ outb(0x40 \| ap->a_areg2); }
	254	#endif UNIX
	255	#ifdef VMS
	256	{ *vms_obj_ptr++ = -1;
	257	*vms_obj_ptr++ = (0x40 \| ap->a_areg2);
	258	dotp->e_xvalue += 1; }
	259	#endif VMS
	260	argtype &= ~AINDX;
	261	}
	262	if (argtype&ASTAR) {
	263	ap->a_areg1 \|= 0x10;
	264	argtype &= ~ASTAR;
	265	}
	266	switch (argtype) {
	267	case AREG: /* %r */
	268	ap->a_areg1 \|= 0x50;
	269	break;
	270	case ABASE: /* (%r) */
	271	ap->a_areg1 \|= 0x60;
	272	break;
	273	case ADECR: /* -(%r) */
	274	ap->a_areg1 \|= 0x70;
	275	break;
	276	case AINCR: /* (%r)+ */
	277	ap->a_areg1 \|= 0x80;
	278	break;
	279	case AEXP: /* expr */
	280	argtype = fetcharg(itab[op], i);
	281	if (argtype == ACCB+TYPB) {
	282	ap->a_areg1 = argtype =
	283	xp->e_xvalue - (dotp->e_xvalue + 1);
	284	if (argtype<MINBYTE \|\| argtype>MAXBYTE)
	285	yyerror("Branch too far"); break;
	286	}
	287	if (argtype == ACCB+TYPW) {
	288	ap->a_areg1 = argtype = xp->e_xvalue
	289	-= dotp->e_xvalue + 2;
	290	xp->e_xtype = XABS;
	291	if (argtype<MINWORD \|\| argtype>MAXWORD)
	292	yyerror("Branch too far");
	293	xp->e_xvalue = argtype>>8;
	294	reloc_how = TYPB;
	295	break;
	296	}
	297	/* reduces to expr(pc) mode */
	298	ap->a_areg1 \|= (0xAF + mod124[ap->a_dispsize]);
	299	reloc_how = type_124[ap->a_dispsize] + RELOC_PCREL;
	300	break;
	301
	302	case ADISP: /* expr(%r) */
	303	ap->a_areg1 \|= 0xA0;
	304	if ((xp->e_xtype&XTYPE)!=XABS \|\| xp->e_xtype&XFORW){
	305	ap->a_areg1 += mod124[ap->a_dispsize];
	306	reloc_how = type_124[ap->a_dispsize];
	307	break;
	308	}
	309	if (xp->e_xvalue==0 && !(ap->a_areg1&0x10)) {
	310	ap->a_areg1 ^= 0xC0;
	311	break;
	312	}
	313	reloc_how = TYPB;
	314	if ((xp->e_xvalue<MINBYTE) \|\| (xp->e_xvalue>MAXBYTE)){
	315	ap->a_areg1 += 0x20;
	316	reloc_how = TYPW;
	317	}
	318	if ((xp->e_xvalue<MINWORD) \|\| (xp->e_xvalue>MAXWORD)){
	319	ap->a_areg1 += 0x20;
	320	reloc_how = TYPL;
	321	}
	322	break;
	323
	324	case AIMM: /* $expr */
	325	if (ap->a_atype&ASTAR)
	326	argtype=TYPL;
	327	else {
	328	argtype = fetcharg(itab[op], i);
	329	if (argtype&ACCA)
	330	argtype=TYPL;
	331	else
	332	argtype &= TYPMASK;
	333	if ( ( (xp->e_xtype&XTYPE) == XABS)
	334	&& !(xp->e_xtype&XFORW)
	335	&& (xp->e_xvalue >= 0)
	336	&& (xp->e_xvalue <= 63)
	337	&& (xp->e_yvalue == 0)
	338	&& (argtype != TYPF)
	339	&& (argtype != TYPD) ) {
	340	ap->a_areg1 = xp->e_xvalue;
	341	break;
	342	}
	343	}
	344	ap->a_areg1 \|= 0x8F;
	345	reloc_how = argtype;
	346	if (reloc_how == TYPD \|\| reloc_how == TYPF){
	347	if ( ((xp->e_xtype&XTYPE)==XABS)
	348	&& (!(xp->e_xtype&XFORW))
	349	&& (slitflt(xp))
	350	){
	351	reloc_how = TYPNONE;
	352	ap->a_areg1=extlitflt(xp);
	353	}
	354	}
	355	break;
	356
	357	} /end of the switch on argtype/
	358	/*
	359	* use the first byte to describe the argument
	360	*/
	361	#ifdef UNIX
	362	outb(ap->a_areg1);
	363	#endif UNIX
	364	#ifdef VMS
	365	vms_obj_ptr++ = -1; vms_obj_ptr++ = (char)(ap->a_areg1);
	366	dotp->e_xvalue += 1;
	367	if ((vms_obj_ptr-sobuf) > 400) {
	368	write(objfil,sobuf,vms_obj_ptr-sobuf);
	369	vms_obj_ptr=sobuf+1;
	370	}
	371	#endif VMS
	372	if (reloc_how != TYPNONE)
	373	outrel(xp, reloc_how);
	374	} /end of the for to pick up all arguments/
	375	}