xref: /csrg-svn/old/pcc/ccom.vax/local2.c (revision 32942)
1 # ifndef lint
2 static char *sccsid ="@(#)local2.c	1.36 (Berkeley) 12/11/87";
3 # endif
4 
5 # include "pass2.h"
6 # include <ctype.h>
7 
8 # define putstr(s)	fputs((s), stdout)
9 
10 # ifdef FORT
11 int ftlab1, ftlab2;
12 # endif
13 /* a lot of the machine dependent parts of the second pass */
14 
15 # define BITMASK(n) ((1L<<n)-1)
16 
17 /*ARGSUSED*/
18 where(c){
19 	fprintf( stderr, "%s, line %d: ", filename, lineno );
20 	}
21 
22 lineid( l, fn ) char *fn; {
23 	/* identify line l and file fn */
24 	printf( "#	line %d, file %s\n", l, fn );
25 	}
26 
27 
28 eobl2(){
29 	register OFFSZ spoff;	/* offset from stack pointer */
30 #ifndef FORT
31 	extern int ftlab1, ftlab2;
32 #endif
33 
34 	spoff = maxoff;
35 	if( spoff >= AUTOINIT ) spoff -= AUTOINIT;
36 	spoff /= SZCHAR;
37 	SETOFF(spoff,4);
38 #ifdef FORT
39 #ifndef FLEXNAMES
40 	printf( "	.set	.F%d,%ld\n", ftnno, spoff );
41 #else
42 	/* SHOULD BE L%d ... ftnno but must change pc/f77 */
43 	printf( "	.set	LF%d,%ld\n", ftnno, spoff );
44 #endif
45 #else
46 	printf( "L%d:\n", ftlab1);
47 	if( spoff!=0 )
48 		if( spoff < 64 )
49 			printf( "	subl2	$%ld,sp\n", spoff);
50 		else
51 			printf( "	movab	-%ld(sp),sp\n", spoff);
52 	printf( "	jbr 	L%d\n", ftlab2);
53 #endif
54 	maxargs = -1;
55 	}
56 
57 struct hoptab { int opmask; char * opstring; } ioptab[] = {
58 
59 	PLUS,	"add",
60 	MINUS,	"sub",
61 	MUL,	"mul",
62 	DIV,	"div",
63 	OR,	"bis",
64 	ER,	"xor",
65 	AND,	"bic",
66 	-1, ""    };
67 
68 hopcode( f, o ){
69 	/* output the appropriate string from the above table */
70 
71 	register struct hoptab *q;
72 
73 	if(asgop(o))
74 		o = NOASG o;
75 	for( q = ioptab;  q->opmask>=0; ++q ){
76 		if( q->opmask == o ){
77 			printf( "%s%c", q->opstring, tolower(f));
78 			return;
79 			}
80 		}
81 	cerror( "no hoptab for %s", opst[o] );
82 	}
83 
84 char *
85 rnames[] = {  /* keyed to register number tokens */
86 
87 	"r0", "r1",
88 	"r2", "r3", "r4", "r5",
89 	"r6", "r7", "r8", "r9", "r10", "r11",
90 	"ap", "fp", "sp", "pc",
91 	};
92 
93 int rstatus[] = {
94 	SAREG|STAREG, SAREG|STAREG,
95 	SAREG|STAREG, SAREG|STAREG, SAREG|STAREG, SAREG|STAREG,
96 	SAREG, SAREG, SAREG, SAREG, SAREG, SAREG,
97 	SAREG, SAREG, SAREG, SAREG,
98 	};
99 
100 tlen(p) NODE *p;
101 {
102 	switch(p->in.type) {
103 		case CHAR:
104 		case UCHAR:
105 			return(1);
106 
107 		case SHORT:
108 		case USHORT:
109 			return(SZSHORT/SZCHAR);
110 
111 		case DOUBLE:
112 			return(SZDOUBLE/SZCHAR);
113 
114 		default:
115 			return(SZINT/SZCHAR);
116 		}
117 }
118 
119 mixtypes(p, q) NODE *p, *q;
120 {
121 	register TWORD tp, tq;
122 
123 	tp = p->in.type;
124 	tq = q->in.type;
125 
126 	return( (tp==FLOAT || tp==DOUBLE) !=
127 		(tq==FLOAT || tq==DOUBLE) );
128 }
129 
130 prtype(n) NODE *n;
131 {
132 	switch (n->in.type)
133 		{
134 
135 		case DOUBLE:
136 			putchar('d');
137 			return;
138 
139 		case FLOAT:
140 			putchar('f');
141 			return;
142 
143 		case LONG:
144 		case ULONG:
145 		case INT:
146 		case UNSIGNED:
147 			putchar('l');
148 			return;
149 
150 		case SHORT:
151 		case USHORT:
152 			putchar('w');
153 			return;
154 
155 		case CHAR:
156 		case UCHAR:
157 			putchar('b');
158 			return;
159 
160 		default:
161 			if ( !ISPTR( n->in.type ) ) cerror("zzzcode- bad type");
162 			else {
163 				putchar('l');
164 				return;
165 				}
166 		}
167 }
168 
169 zzzcode( p, c ) register NODE *p; {
170 	register int m;
171 	int val;
172 	switch( c ){
173 
174 	case 'N':  /* logical ops, turned into 0-1 */
175 		/* use register given by register 1 */
176 		cbgen( 0, m=getlab(), 'I' );
177 		deflab( p->bn.label );
178 		printf( "	clrl	%s\n", rnames[getlr( p, '1' )->tn.rval] );
179 		deflab( m );
180 		return;
181 
182 	case 'P':
183 		cbgen( p->in.op, p->bn.label, c );
184 		return;
185 
186 	case 'A':
187 	case 'V':
188 		sconv( p, c == 'V' );
189 		return;
190 
191 	case 'G':	/* i *= f; asgops with int lhs and float rhs */
192 		{
193 		register NODE *l, *r, *s;
194 		int rt;
195 
196 		l = p->in.left;
197 		r = p->in.right;
198 		s = talloc();
199 		rt = r->in.type;
200 
201 		s->in.op = SCONV;
202 		s->in.left = l;
203 		s->in.type = rt;
204 		zzzcode(s, 'A');
205 		putstr("\n\t");
206 
207 		hopcode(rt == FLOAT ? 'F' : 'D', p->in.op);
208 		putstr("2\t");
209 		adrput(r);
210 		putchar(',');
211 		adrput(resc);
212 		putstr("\n\t");
213 
214 		s->in.op = ASSIGN;
215 		s->in.left = l;
216 		s->in.right = resc;
217 		s->in.type = l->in.type;
218 		zzzcode(s, 'A');
219 
220 		s->in.op = FREE;
221 		return;
222 		}
223 
224 	case 'J':	/* unsigned DIV/MOD with constant divisors */
225 		{
226 		register int ck = INAREG;
227 		int label1, label2;
228 
229 		/* case constant <= 1 is handled by optim() in pass 1 */
230 		/* case constant < 0x80000000 is handled in table */
231 		switch( p->in.op ) {
232 		/* case DIV: handled in optim2() */
233 		case MOD:
234 			if( p->in.left->in.op == REG &&
235 			    p->in.left->tn.rval == resc->tn.rval )
236 				goto asgmod;
237 			label1 = getlab();
238 			expand(p, ck, "movl\tAL,A1\n\tcmpl\tA1,AR\n");
239 			printf("\tjlssu\tL%d\n", label1);
240 			expand(p, ck, "\tsubl2\tAR,A1\n");
241 			printf("L%d:", label1);
242 			break;
243 		case ASG DIV:
244 			label1 = getlab();
245 			label2 = getlab();
246 			expand(p, ck, "cmpl\tAL,AR\n");
247 			printf("\tjgequ\tL%d\n", label1);
248 			expand(p, ck, "\tmovl\t$1,AL\n");
249 			printf("\tjbr\tL%d\nL%d:\n", label2, label1);
250 			expand(p, ck, "\tclrl\tAL\n");
251 			printf("L%d:", label2);
252 			break;
253 		case ASG MOD:
254 		asgmod:
255 			label1 = getlab();
256 			expand(p, ck, "cmpl\tAL,AR\n");
257 			printf("\tjlssu\tL%d\n", label1);
258 			expand(p, ck, "\tsubl2\tAR,AL\n");
259 			printf("L%d:", label1);
260 			break;
261 			}
262 		return;
263 		}
264 
265 	case 'B':	/* get oreg value in temp register for left shift */
266 		{
267 		register NODE *r;
268 		if (xdebug) eprint(p, 0, &val, &val);
269 		r = p->in.right;
270 		if( tlen(r) == SZINT/SZCHAR && r->in.type != FLOAT )
271 			putstr("movl");
272 		else {
273 			putstr(ISUNSIGNED(r->in.type) ? "movz" : "cvt");
274 			prtype(r);
275 			putchar('l');
276 			}
277 		return;
278 		}
279 
280 	case 'C':	/* num words pushed on arg stack */
281 		{
282 		extern int gc_numbytes;
283 		extern int xdebug;
284 
285 		if (xdebug) printf("->%d<-",gc_numbytes);
286 
287 		printf("$%d", gc_numbytes/(SZLONG/SZCHAR) );
288 		return;
289 		}
290 
291 	case 'D':	/* INCR and DECR */
292 		zzzcode(p->in.left, 'A');
293 		putchar('\n');
294 		putchar('\t');
295 
296 	case 'E':	/* INCR and DECR, FOREFF */
297 		if (p->in.right->in.op == ICON && p->in.right->tn.lval == 1)
298 			{
299 			putstr(p->in.op == INCR ? "inc" : "dec");
300 			prtype(p->in.left);
301 			putchar('\t');
302 			adrput(p->in.left);
303 			return;
304 			}
305 		putstr(p->in.op == INCR ? "add" : "sub");
306 		prtype(p->in.left);
307 		putchar('2');
308 		putchar('\t');
309 		adrput(p->in.right);
310 		putchar(',');
311 		adrput(p->in.left);
312 		return;
313 
314 	case 'F':	/* register type of right operand */
315 		{
316 		register NODE *n;
317 		extern int xdebug;
318 		register int ty;
319 
320 		n = getlr( p, 'R' );
321 		ty = n->in.type;
322 
323 		if (xdebug) printf("->%d<-", ty);
324 
325 		if ( ty==DOUBLE) putchar('d');
326 		else if ( ty==FLOAT ) putchar('f');
327 		else putchar('l');
328 		return;
329 		}
330 
331 	case 'L':	/* type of left operand */
332 	case 'R':	/* type of right operand */
333 		{
334 		register NODE *n;
335 		extern int xdebug;
336 
337 		n = getlr( p, c );
338 		if (xdebug) printf("->%d<-", n->in.type);
339 
340 		prtype(n);
341 		return;
342 		}
343 
344 	case 'Z':	/* AND for CC with ICON -- lval is complemented */
345 		{
346 		register NODE *l, *r;
347 
348 		l = getlr( p, 'L' );
349 		r = getlr( p, 'R' );
350 		m = (1 << tlen(l) * SZCHAR) - 1;
351 		r->tn.lval = ~r->tn.lval;
352 		if( (l->in.type == CHAR || l->in.type == SHORT) &&
353 		    (r->tn.lval & ~m) ) {
354 			putstr("cvt");
355 			prtype(l);
356 			putstr("l\t");
357 			adrput(l);
358 			putchar(',');
359 			adrput(resc);
360 			putstr("\n\t");
361 			resc->tn.type = INT;
362 			l = resc;
363 			}
364 		else if( l->in.type == UCHAR || l->in.type == USHORT )
365 			/* remove trash left over from complementing */
366 			r->tn.lval &= m;
367 		putstr("bit");
368 		prtype(l);
369 		printf("\t$%ld", r->tn.lval);
370 		putchar(',');
371 		adrput(l);
372 		return;
373 		}
374 
375 	case 'U':	/* 32 - n, for unsigned right shifts */
376 		printf("$%d", 32 - p->in.right->tn.lval );
377 		return;
378 
379 	case 'T':	/* rounded structure length for arguments */
380 		{
381 		int size;
382 
383 		size = p->stn.stsize;
384 		SETOFF( size, 4);
385 		printf("$%d", size);
386 		return;
387 		}
388 
389 	case 'S':  /* structure assignment */
390 		stasg(p);
391 		break;
392 
393 	default:
394 		cerror( "illegal zzzcode" );
395 		}
396 	}
397 
398 stasg(p)
399 	register NODE *p;
400 {
401 	register NODE *l, *r;
402 	register size;
403 
404 	if( p->in.op == STASG ){
405 		l = p->in.left;
406 		r = p->in.right;
407 
408 		}
409 	else if( p->in.op == STARG ){  /* store an arg into a temporary */
410 		r = p->in.left;
411 		}
412 	else cerror( "STASG bad" );
413 
414 	if( r->in.op == ICON ) r->in.op = NAME;
415 	else if( r->in.op == REG ) r->in.op = OREG;
416 	else if( r->in.op != OREG ) cerror( "STASG-r" );
417 
418 	size = p->stn.stsize;
419 
420 	if( size <= 0 || size > 65535 )
421 		cerror("structure size <0=0 or >65535");
422 
423 	switch(size) {
424 		case 1:
425 			putstr("	movb	");
426 			break;
427 		case 2:
428 			putstr("	movw	");
429 			break;
430 		case 4:
431 			putstr("	movl	");
432 			break;
433 		case 8:
434 			putstr("	movq	");
435 			break;
436 		default:
437 			printf("	movc3	$%d,", size);
438 			break;
439 	}
440 	adrput(r);
441 	if( p->in.op == STASG ){
442 		putchar(',');
443 		adrput(l);
444 		putchar('\n');
445 		}
446 	else
447 		putstr(",(sp)\n");
448 
449 	if( r->in.op == NAME ) r->in.op = ICON;
450 	else if( r->in.op == OREG ) r->in.op = REG;
451 	}
452 
453 NODE *makearg( ty ) int ty; {
454 	register NODE *p, *q;
455 
456 	/* build a -(sp) operand */
457 	p = talloc();
458 	p->in.op = REG;
459 	/* the type needn't be right, just consistent */
460 	p->in.type = INCREF(ty);
461 	p->tn.rval = SP;
462 	p->tn.lval = 0;
463 	q = talloc();
464 	q->in.op = ASG MINUS;
465 	q->in.type = INCREF(ty);
466 	q->in.left = p;
467 	p = talloc();
468 	p->in.op = ICON;
469 	p->in.type = INT;
470 	p->tn.name = "";
471 	/* size of floating argument is always 2 */
472 	p->tn.lval = (1 + (ty == FLOAT || ty == DOUBLE)) * (SZINT/SZCHAR);
473 	q->in.right = p;
474 	p = talloc();
475 	p->in.op = UNARY MUL;
476 	p->in.left = q;
477 	return( p );
478 	}
479 
480 sconv( p, forarg ) register NODE *p; {
481 	register NODE *l, *r;
482 	int m, val;
483 
484 	if (xdebug) eprint(p, 0, &val, &val);
485 	r = getlr(p, 'R');
486 	if (p->in.op == ASSIGN)
487 		l = getlr(p, 'L');
488 	else if (p->in.op == SCONV) {
489 		m = r->in.type;
490 		if (forarg)
491 			l = makearg( m );
492 		else
493 			l = resc;
494 		l->in.type = m;
495 		r = getlr(p, 'L');
496 		}
497 	else {		/* OPLTYPE */
498 		m = (r->in.type==FLOAT || r->in.type==DOUBLE ? r->in.type : INT);
499 		if (forarg)
500 			l = makearg( m );
501 		else
502 			l = resc;
503 		l->in.type = m;
504 		}
505 	if (r->in.op == ICON)
506 		if (r->in.name[0] == '\0') {
507 			if (r->tn.lval == 0 &&
508 			    (r->in.type == DOUBLE || r->in.type == FLOAT ||
509 			    !forarg)) {
510 				if (r->in.type == FLOAT)
511 					r->in.type = DOUBLE;
512 				putstr("clr");
513 				prtype(l);
514 				putchar('\t');
515 				adrput(l);
516 				goto cleanup;
517 				}
518 			if (r->tn.lval < 0 && r->tn.lval >= -63) {
519 				putstr("mneg");
520 				prtype(l);
521 				r->tn.lval = -r->tn.lval;
522 				goto ops;
523 				}
524 			if (r->tn.lval < 0)
525 				r->in.type = r->tn.lval >= -128 ? CHAR
526 					: (r->tn.lval >= -32768 ? SHORT
527 					: INT);
528 			else if (l->in.type == FLOAT ||
529 			    l->in.type == DOUBLE)
530 				r->in.type = r->tn.lval <= 63 ? INT
531 					: (r->tn.lval <= 127 ? CHAR
532 					: (r->tn.lval <= 32767 ? SHORT
533 					: INT));
534 			else
535 				r->in.type = r->tn.lval <= 63 ? INT
536 					: (r->tn.lval <= 127 ? CHAR
537 					: (r->tn.lval <= 255 ? UCHAR
538 					: (r->tn.lval <= 32767 ? SHORT
539 					: (r->tn.lval <= 65535 ? USHORT
540 					: INT))));
541 			if (forarg && r->in.type == INT) {
542 				putstr("pushl\t");
543 				adrput(r);
544 				goto cleanup;
545 				}
546 			}
547 		else {
548 			if (forarg && tlen(r) == SZINT/SZCHAR) {
549 				putstr("pushl\t");
550 				adrput(r);
551 				goto cleanup;
552 				}
553 			putstr("moval\t");
554 			acon(r);
555 			putchar(',');
556 			adrput(l);
557 			goto cleanup;
558 			}
559 
560 	if (p->in.op == SCONV &&
561 	    !(l->in.type == FLOAT || l->in.type == DOUBLE) &&
562 	    !mixtypes(l, r)) {
563 		/*
564 		 * Because registers must always contain objects
565 		 * of the same width as INTs, we may have to
566 		 * perform two conversions to get an INT.  Can
567 		 * the conversions be collapsed into one?
568 		 */
569 		if (m = collapsible(l, r))
570 			r->in.type = m;
571 		else {
572 			/*
573 			 * Two steps are required.
574 			 */
575 			NODE *x;
576 
577 			if (forarg) {
578 				x = resc;
579 				x->in.type = l->in.type;
580 				}
581 			else {
582 				x = &resc[1];
583 				*x = *l;
584 				}
585 
586 			if (tlen(x) > tlen(r) && ISUNSIGNED(r->in.type))
587 				putstr("movz");
588 			else
589 				putstr("cvt");
590 			prtype(r);
591 			prtype(x);
592 			putchar('\t');
593 			adrput(r);
594 			putchar(',');
595 			adrput(x);
596 			putchar('\n');
597 			putchar('\t');
598 			r = x;
599 			}
600 		l->in.type = (ISUNSIGNED(l->in.type) ? UNSIGNED : INT);
601 		}
602 
603 	if ((r->in.type == UNSIGNED || r->in.type == ULONG) &&
604 	    mixtypes(l, r)) {
605 		int label1, label2;
606 		NODE *x = NULL;
607 
608 #if defined(FORT) || defined(SPRECC)
609 		if (forarg)
610 #else
611 		if (forarg || l == resc)
612 #endif
613 			{
614 			/* compute in register, convert to double when done */
615 			x = l;
616 			l = resc;
617 			l->in.type = x->in.type;
618 			}
619 
620 		label1 = getlab();
621 		label2 = getlab();
622 
623 		putstr("movl\t");
624 		adrput(r);
625 		putchar(',');
626 		adrput(l);
627 		putstr("\n\tjbsc\t$31,");
628 		adrput(l);
629 		printf(",L%d\n\tcvtl", label1);
630 		prtype(l);
631 		putchar('\t');
632 		adrput(l);
633 		putchar(',');
634 		adrput(l);
635 		printf("\n\tjbr\tL%d\nL%d:\n\tcvtl", label2, label1);
636 		prtype(l);
637 		putchar('\t');
638 		adrput(l);
639 		putchar(',');
640 		adrput(l);
641 		putstr("\n\tadd");
642 		prtype(l);
643 		putstr("2\t$0");
644 		prtype(l);
645 		putstr("2.147483648e9,");
646 		adrput(l);
647 		printf("\nL%d:", label2);
648 
649 		if (!forarg && (l->in.type == DOUBLE || l != resc))
650 			goto cleanup;
651 		if (x != NULL) {
652 			if (l == x) {
653 				r = &resc[1];
654 				*r = *l;
655 				}
656 			else {
657 				r = l;
658 				l = x;
659 				}
660 			l->in.type = DOUBLE;
661 			}
662 		putstr("\n\t");
663 		}
664 
665 	if( (l->in.type == FLOAT || l->in.type == DOUBLE) &&
666 	    (r->in.type == UCHAR || r->in.type == USHORT) ) {
667 		/* skip unnecessary unsigned to floating conversion */
668 #if defined(FORT) || defined(SPRECC)
669 		if (forarg)
670 #else
671 		if (forarg || l == resc)
672 #endif
673 			l->in.type = DOUBLE;
674 		putstr("movz");
675 		prtype(r);
676 		putstr("l\t");
677 		adrput(r);
678 		putchar(',');
679 		adrput(resc);
680 		putstr("\n\t");
681 		if (l == resc) {
682 			r = &resc[1];
683 			*r = *l;
684 			}
685 		else
686 			r = resc;
687 		r->in.type = INT;
688 		}
689 
690 #if defined(FORT) || defined(SPRECC)
691 	if (forarg && l->in.type == FLOAT)
692 #else
693 	if ((forarg || l == resc) && l->in.type == FLOAT)
694 #endif
695 		{
696 		/* perform an implicit conversion to double */
697 		l->in.type = DOUBLE;
698 		if (r->in.type != FLOAT &&
699 		    r->in.type != CHAR &&
700 		    r->in.type != SHORT) {
701 			/* trim bits from the mantissa */
702 			putstr("cvt");
703 			prtype(r);
704 			putstr("f\t");
705 			adrput(r);
706 			putchar(',');
707 			adrput(resc);
708 			putstr("\n\t");
709 			if (l == resc) {
710 				r = &resc[1];
711 				*r = *l;
712 				}
713 			else
714 				r = resc;
715 			r->in.type = FLOAT;
716 			}
717 		}
718 
719 	if (!mixtypes(l,r)) {
720 		if (tlen(l) == tlen(r)) {
721 			if (forarg && tlen(l) == SZINT/SZCHAR) {
722 				putstr("pushl\t");
723 				adrput(r);
724 				goto cleanup;
725 				}
726 			putstr("mov");
727 #ifdef FORT
728 			if (Oflag)
729 				prtype(l);
730 			else {
731 				if (l->in.type == DOUBLE)
732 					putchar('q');
733 				else if(l->in.type == FLOAT)
734 					putchar('l');
735 				else
736 					prtype(l);
737 				}
738 #else
739 			prtype(l);
740 #endif FORT
741 			goto ops;
742 			}
743 		else if (tlen(l) > tlen(r) && ISUNSIGNED(r->in.type))
744 			putstr("movz");
745 		else
746 			putstr("cvt");
747 		}
748 	else
749 		putstr("cvt");
750 	prtype(r);
751 	prtype(l);
752 ops:
753 	putchar('\t');
754 	adrput(r);
755 	putchar(',');
756 	adrput(l);
757 
758 cleanup:
759 	if (forarg)
760 		tfree(l);
761 	}
762 
763 /*
764  * collapsible(dest, src) -- if a conversion with a register destination
765  *	can be accomplished in one instruction, return the type of src
766  *	that will do the job correctly; otherwise return 0.  Note that
767  *	a register must always end up having type INT or UNSIGNED.
768  */
769 int
770 collapsible(dest, src)
771 NODE *dest, *src;
772 {
773 	int st = src->in.type;
774 	int dt = dest->in.type;
775 	int newt = 0;
776 
777 	/*
778 	 * Are there side effects of evaluating src?
779 	 * If the derived type will not be the same size as src,
780 	 * we may have to use two steps.
781 	 */
782 	if (tlen(src) > tlen(dest)) {
783 		if (tshape(src, STARREG))
784 			return (0);
785 		if (src->in.op == OREG && R2TEST(src->tn.rval))
786 			return (0);
787 		}
788 
789 	/*
790 	 * Can we get an object of dest's type by punning src?
791 	 * Praises be to great Cthulhu for little-endian machines...
792 	 */
793 	if (st == CHAR && dt == USHORT)
794 		/*
795 		 * Special case -- we must sign-extend to 16 bits.
796 		 */
797 		return (0);
798 
799 	if (tlen(src) < tlen(dest))
800 		newt = st;
801 	else
802 		newt = dt;
803 
804 	return (newt);
805 	}
806 
807 rmove( rt, rs, t ) TWORD t; {
808 	printf( "	%s	%s,%s\n",
809 #ifdef FORT
810 		!Oflag ? (t==DOUBLE ? "movq" : "movl") :
811 #endif
812 		(t==FLOAT ? "movf" : (t==DOUBLE ? "movd" : "movl")),
813 		rnames[rs], rnames[rt] );
814 	}
815 
816 struct respref
817 respref[] = {
818 	INTAREG|INTBREG,	INTAREG|INTBREG,
819 	INAREG|INBREG,	INAREG|INBREG|SOREG|STARREG|STARNM|SNAME|SCON,
820 	INTEMP,	INTEMP,
821 	FORARG,	FORARG,
822 	INTEMP,	INTAREG|INAREG|INTBREG|INBREG|SOREG|STARREG|STARNM,
823 	0,	0 };
824 
825 setregs(){ /* set up temporary registers */
826 	fregs = 6;	/* tbl- 6 free regs on VAX (0-5) */
827 	}
828 
829 /*ARGSUSED*/
830 rewfld( p ) NODE *p; {
831 	return(1);
832 	}
833 
834 /*ARGSUSED*/
835 callreg(p) NODE *p; {
836 	return( R0 );
837 	}
838 
839 base( p ) register NODE *p; {
840 	register int o = p->in.op;
841 
842 	if( o==ICON && p->tn.name[0] != '\0' ) return( 100 ); /* ie no base reg */
843 	if( o==REG ) return( p->tn.rval );
844     if( (o==PLUS || o==MINUS) && p->in.left->in.op == REG && p->in.right->in.op==ICON)
845 		return( p->in.left->tn.rval );
846     if( o==OREG && !R2TEST(p->tn.rval) && (p->in.type==INT || p->in.type==UNSIGNED || ISPTR(p->in.type)) )
847 		return( p->tn.rval + 0200*1 );
848 	if( o==INCR && p->in.left->in.op==REG ) return( p->in.left->tn.rval + 0200*2 );
849 	if( o==ASG MINUS && p->in.left->in.op==REG) return( p->in.left->tn.rval + 0200*4 );
850 	if( o==UNARY MUL && p->in.left->in.op==INCR && p->in.left->in.left->in.op==REG
851 	  && (p->in.type==INT || p->in.type==UNSIGNED || ISPTR(p->in.type)) )
852 		return( p->in.left->in.left->tn.rval + 0200*(1+2) );
853 	if( o==NAME ) return( 100 + 0200*1 );
854 	return( -1 );
855 	}
856 
857 offset( p, tyl ) register NODE *p; int tyl; {
858 
859 	if( tyl==1 &&
860 	    p->in.op==REG &&
861 	    (p->in.type==INT || p->in.type==UNSIGNED) )
862 		return( p->tn.rval );
863 	if( p->in.op==LS &&
864 	    p->in.left->in.op==REG &&
865 	    (p->in.left->in.type==INT || p->in.left->in.type==UNSIGNED) &&
866 	    p->in.right->in.op==ICON &&
867 	    p->in.right->in.name[0]=='\0' &&
868 	    (1<<p->in.right->tn.lval)==tyl)
869 		return( p->in.left->tn.rval );
870 	if( tyl==2 &&
871 	    p->in.op==PLUS &&
872 	    (p->in.left->in.type==INT || p->in.left->in.type==UNSIGNED) &&
873 	    p->in.left->in.op==REG &&
874 	    p->in.right->in.op==REG &&
875 	    p->in.left->tn.rval==p->in.right->tn.rval )
876 		return( p->in.left->tn.rval );
877 	return( -1 );
878 	}
879 
880 makeor2( p, q, b, o) register NODE *p, *q; register int b, o; {
881 	register NODE *t;
882 	NODE *f;
883 
884 	p->in.op = OREG;
885 	f = p->in.left; 	/* have to free this subtree later */
886 
887 	/* init base */
888 	switch (q->in.op) {
889 		case ICON:
890 		case REG:
891 		case OREG:
892 		case NAME:
893 			t = q;
894 			break;
895 
896 		case MINUS:
897 			q->in.right->tn.lval = -q->in.right->tn.lval;
898 		case PLUS:
899 			t = q->in.right;
900 			break;
901 
902 		case INCR:
903 		case ASG MINUS:
904 			t = q->in.left;
905 			break;
906 
907 		case UNARY MUL:
908 			t = q->in.left->in.left;
909 			break;
910 
911 		default:
912 			cerror("illegal makeor2");
913 	}
914 
915 	p->tn.lval = t->tn.lval;
916 #ifndef FLEXNAMES
917 	{
918 		register int i;
919 		for(i=0; i<NCHNAM; ++i)
920 			p->in.name[i] = t->in.name[i];
921 	}
922 #else
923 	p->in.name = t->in.name;
924 #endif
925 
926 	/* init offset */
927 	p->tn.rval = R2PACK( (b & 0177), o, (b>>7) );
928 
929 	tfree(f);
930 	return;
931 	}
932 
933 canaddr( p ) NODE *p; {
934 	register int o = p->in.op;
935 
936 	if( o==NAME || o==REG || o==ICON || o==OREG || (o==UNARY MUL && shumul(p->in.left)) ) return(1);
937 	return(0);
938 	}
939 
940 flshape( p ) NODE *p; {
941 	register int o = p->in.op;
942 
943 	return( o == REG || o == NAME || o == ICON ||
944 		(o == OREG && (!R2TEST(p->tn.rval) || tlen(p) == 1)) );
945 	}
946 
947 /* INTEMP shapes must not contain any temporary registers */
948 shtemp( p ) register NODE *p; {
949 	int r;
950 
951 	if( p->in.op == STARG ) p = p->in.left;
952 
953 	switch (p->in.op) {
954 	case REG:
955 		return( !istreg(p->tn.rval) );
956 	case OREG:
957 		r = p->tn.rval;
958 		if( R2TEST(r) ) {
959 			if( istreg(R2UPK1(r)) )
960 				return(0);
961 			r = R2UPK2(r);
962 			}
963 		return( !istreg(r) );
964 	case UNARY MUL:
965 		p = p->in.left;
966 		return( p->in.op != UNARY MUL && shtemp(p) );
967 		}
968 
969 	if( optype( p->in.op ) != LTYPE ) return(0);
970 	return(1);
971 	}
972 
973 shumul( p ) register NODE *p; {
974 	register int o;
975 	extern int xdebug;
976 
977 	if (xdebug) {
978 		int val;
979 		printf("shumul:\n");
980 		eprint(p, 0, &val, &val);
981 		}
982 
983 	o = p->in.op;
984 	if( o == NAME || (o == OREG && !R2TEST(p->tn.rval)) || o == ICON ) return( STARNM );
985 
986 	if( ( o == INCR || o == ASG MINUS ) &&
987 	    ( p->in.left->in.op == REG && p->in.right->in.op == ICON ) &&
988 	    p->in.right->in.name[0] == '\0' )
989 		{
990 		switch (p->in.type)
991 			{
992 			case CHAR|PTR:
993 			case UCHAR|PTR:
994 				o = 1;
995 				break;
996 
997 			case SHORT|PTR:
998 			case USHORT|PTR:
999 				o = 2;
1000 				break;
1001 
1002 			case INT|PTR:
1003 			case UNSIGNED|PTR:
1004 			case LONG|PTR:
1005 			case ULONG|PTR:
1006 			case FLOAT|PTR:
1007 				o = 4;
1008 				break;
1009 
1010 			case DOUBLE|PTR:
1011 				o = 8;
1012 				break;
1013 
1014 			default:
1015 				if ( ISPTR(p->in.type) &&
1016 				     ISPTR(DECREF(p->in.type)) ) {
1017 					o = 4;
1018 					break;
1019 					}
1020 				else return(0);
1021 			}
1022 		return( p->in.right->tn.lval == o ? STARREG : 0);
1023 		}
1024 
1025 	return( 0 );
1026 	}
1027 
1028 adrcon( val ) CONSZ val; {
1029 	putchar( '$' );
1030 	printf( CONFMT, val );
1031 	}
1032 
1033 conput( p ) register NODE *p; {
1034 	switch( p->in.op ){
1035 
1036 	case ICON:
1037 		acon( p );
1038 		return;
1039 
1040 	case REG:
1041 		putstr( rnames[p->tn.rval] );
1042 		return;
1043 
1044 	default:
1045 		cerror( "illegal conput" );
1046 		}
1047 	}
1048 
1049 /*ARGSUSED*/
1050 insput( p ) NODE *p; {
1051 	cerror( "insput" );
1052 	}
1053 
1054 upput( p, size ) NODE *p; int size; {
1055 	if( size == SZLONG && p->in.op == REG ) {
1056 		putstr( rnames[p->tn.rval + 1] );
1057 		return;
1058 		}
1059 	cerror( "upput" );
1060 	}
1061 
1062 adrput( p ) register NODE *p; {
1063 	register int r;
1064 	/* output an address, with offsets, from p */
1065 
1066 	if( p->in.op == FLD ){
1067 		p = p->in.left;
1068 		}
1069 	switch( p->in.op ){
1070 
1071 	case NAME:
1072 		acon( p );
1073 		return;
1074 
1075 	case ICON:
1076 		/* addressable value of the constant */
1077 		putchar( '$' );
1078 		acon( p );
1079 		return;
1080 
1081 	case REG:
1082 		putstr( rnames[p->tn.rval] );
1083 		return;
1084 
1085 	case OREG:
1086 		r = p->tn.rval;
1087 		if( R2TEST(r) ){ /* double indexing */
1088 			register int flags;
1089 
1090 			flags = R2UPK3(r);
1091 			if( flags & 1 ) putchar('*');
1092 			if( flags & 4 ) putchar('-');
1093 			if( p->tn.lval != 0 || p->in.name[0] != '\0' ) acon(p);
1094 			if( R2UPK1(r) != 100) printf( "(%s)", rnames[R2UPK1(r)] );
1095 			if( flags & 2 ) putchar('+');
1096 			printf( "[%s]", rnames[R2UPK2(r)] );
1097 			return;
1098 			}
1099 		if( r == AP ){  /* in the argument region */
1100 			if( p->in.name[0] != '\0' ) werror( "bad arg temp" );
1101 			printf( CONFMT, p->tn.lval );
1102 			putstr( "(ap)" );
1103 			return;
1104 			}
1105 		if( p->tn.lval != 0 || p->in.name[0] != '\0') acon( p );
1106 		printf( "(%s)", rnames[p->tn.rval] );
1107 		return;
1108 
1109 	case UNARY MUL:
1110 		/* STARNM or STARREG found */
1111 		if( tshape(p, STARNM) ) {
1112 			putchar( '*' );
1113 			adrput( p->in.left);
1114 			}
1115 		else {	/* STARREG - really auto inc or dec */
1116 			register NODE *q;
1117 
1118 			q = p->in.left;
1119 			if( q->in.right->tn.lval != tlen(p) )
1120 				cerror("adrput: bad auto-increment/decrement");
1121 			printf("%s(%s)%s", (q->in.op==INCR ? "" : "-"),
1122 				rnames[q->in.left->tn.rval],
1123 				(q->in.op==INCR ? "+" : "") );
1124 			p->in.op = OREG;
1125 			p->tn.rval = q->in.left->tn.rval;
1126 			p->tn.lval = (q->in.op == INCR ? -q->in.right->tn.lval : 0);
1127 #ifndef FLEXNAMES
1128 			p->in.name[0] = '\0';
1129 #else
1130 			p->in.name = "";
1131 #endif
1132 			tfree(q);
1133 		}
1134 		return;
1135 
1136 	default:
1137 		cerror( "illegal address" );
1138 		return;
1139 
1140 		}
1141 
1142 	}
1143 
1144 acon( p ) register NODE *p; { /* print out a constant */
1145 
1146 	if( p->in.name[0] == '\0' )
1147 		printf( CONFMT, p->tn.lval);
1148 	else {
1149 #ifndef FLEXNAMES
1150 		printf( "%.8s", p->in.name );
1151 #else
1152 		putstr( p->in.name );
1153 #endif
1154 		if( p->tn.lval != 0 ) {
1155 			putchar( '+' );
1156 			printf( CONFMT, p->tn.lval );
1157 			}
1158 		}
1159 	}
1160 
1161 genscall( p, cookie ) register NODE *p; {
1162 	/* structure valued call */
1163 	return( gencall( p, cookie ) );
1164 	}
1165 
1166 /* tbl */
1167 int gc_numbytes;
1168 /* tbl */
1169 
1170 /*ARGSUSED*/
1171 gencall( p, cookie ) register NODE *p; {
1172 	/* generate the call given by p */
1173 	register NODE *p1;
1174 	register int temp, temp1;
1175 	register int m;
1176 
1177 	if( p->in.right ) temp = argsize( p->in.right );
1178 	else temp = 0;
1179 
1180 	if( p->in.op == STCALL || p->in.op == UNARY STCALL ){
1181 		/* set aside room for structure return */
1182 
1183 		if( p->stn.stsize > temp ) temp1 = p->stn.stsize;
1184 		else temp1 = temp;
1185 		}
1186 
1187 	if( temp > maxargs ) maxargs = temp;
1188 	SETOFF(temp1,4);
1189 
1190 	if( p->in.right ){ /* make temp node, put offset in, and generate args */
1191 		genargs( p->in.right );
1192 		}
1193 
1194 	p1 = p->in.left;
1195 	if( p1->in.op != ICON ){
1196 		if( p1->in.op != REG ){
1197 			if( p1->in.op != OREG || R2TEST(p1->tn.rval) ){
1198 				if( p1->in.op != NAME ){
1199 					order( p1, INAREG );
1200 					}
1201 				}
1202 			}
1203 		}
1204 
1205 /* tbl
1206 	setup gc_numbytes so reference to ZC works */
1207 
1208 	gc_numbytes = temp&(0x3ff);
1209 /* tbl */
1210 
1211 	p->in.op = UNARY CALL;
1212 	m = match( p, INTAREG|INTBREG );
1213 
1214 	/* compensate for deficiency in 'ret' instruction ... wah,kre */
1215 	/* (plus in assignment to gc_numbytes above, for neatness only) */
1216 	if (temp >= 1024)
1217 		printf("	addl2	$%d,sp\n", (temp&(~0x3ff)));
1218 
1219 	return(m != MDONE);
1220 	}
1221 
1222 /* tbl */
1223 char *
1224 ccbranches[] = {
1225 	"eql",
1226 	"neq",
1227 	"leq",
1228 	"lss",
1229 	"geq",
1230 	"gtr",
1231 	"lequ",
1232 	"lssu",
1233 	"gequ",
1234 	"gtru",
1235 	};
1236 /* tbl */
1237 
1238 /*ARGSUSED*/
1239 cbgen( o, lab, mode ) { /*   printf conditional and unconditional branches */
1240 
1241 	if( o != 0 && ( o < EQ || o > UGT ) )
1242 		cerror( "bad conditional branch: %s", opst[o] );
1243 	printf( "	j%s	L%d\n", o == 0 ? "br" : ccbranches[o-EQ], lab );
1244 	}
1245 
1246 nextcook( p, cookie ) NODE *p; {
1247 	/* we have failed to match p with cookie; try another */
1248 	if( cookie == FORREW ) return( 0 );  /* hopeless! */
1249 	if( !(cookie&(INTAREG|INTBREG)) ) return( INTAREG|INTBREG );
1250 	if( !(cookie&INTEMP) && asgop(p->in.op) ) return( INTEMP|INAREG|INTAREG|INTBREG|INBREG );
1251 	return( FORREW );
1252 	}
1253 
1254 /*ARGSUSED*/
1255 lastchance( p, cook ) NODE *p; {
1256 	/* forget it! */
1257 	return(0);
1258 	}
1259 
1260 optim2( p ) register NODE *p; {
1261 	/* do local tree transformations and optimizations */
1262 
1263 	int o;
1264 	int i, mask;
1265 	register NODE *l, *r;
1266 
1267 	switch( o = p->in.op ) {
1268 
1269 	case AND:
1270 		/* commute L and R to eliminate complements and constants */
1271 		if( (l = p->in.left)->in.op == ICON && l->in.name[0] == 0 ||
1272 		    l->in.op == COMPL ) {
1273 			p->in.left = p->in.right;
1274 			p->in.right = l;
1275 			}
1276 	case ASG AND:
1277 		/* change meaning of AND to ~R&L - bic on pdp11 */
1278 		r = p->in.right;
1279 		if( r->in.op==ICON && r->in.name[0]==0 ) {
1280 			/* check for degenerate operations */
1281 			l = p->in.left;
1282 			mask = (1 << tlen(l) * SZCHAR) - 1;
1283 			if( ISUNSIGNED(r->in.type) ) {
1284 				i = (~r->tn.lval & mask);
1285 				if( i == 0 ) {
1286 					r->in.op = FREE;
1287 					ncopy(p, l);
1288 					l->in.op = FREE;
1289 					break;
1290 					}
1291 				else if( i == mask )
1292 					goto zero;
1293 				else
1294 					r->tn.lval = i;
1295 				break;
1296 				}
1297 			else if( r->tn.lval == mask &&
1298 				 tlen(l) < SZINT/SZCHAR ) {
1299 				r->in.op = SCONV;
1300 				r->in.left = l;
1301 				r->in.right = 0;
1302 				r->in.type = ENUNSIGN(l->in.type);
1303 				r->in.su = l->in.su > 1 ? l->in.su : 1;
1304 				ncopy(p, r);
1305 				p->in.left = r;
1306 				p->in.type = INT;
1307 				break;
1308 				}
1309 			/* complement constant */
1310 			r->tn.lval = ~r->tn.lval;
1311 			}
1312 		else if( r->in.op==COMPL ) { /* ~~A => A */
1313 			r->in.op = FREE;
1314 			p->in.right = r->in.left;
1315 			}
1316 		else { /* insert complement node */
1317 			p->in.right = l = talloc();
1318 			l->in.op = COMPL;
1319 			l->in.rall = NOPREF;
1320 			l->in.type = r->in.type;
1321 			l->in.left = r;
1322 			l->in.right = NULL;
1323 			}
1324 		break;
1325 
1326 	case SCONV:
1327 		l = p->in.left;
1328 #if defined(FORT) || defined(SPRECC)
1329 		if( p->in.type == FLOAT || p->in.type == DOUBLE ||
1330 		    l->in.type == FLOAT || l->in.type == DOUBLE )
1331 			return;
1332 #else
1333 		if( mixtypes(p, l) ) return;
1334 #endif
1335 		if( l->in.op == PCONV )
1336 			return;
1337 		if( (l->in.op == CALL || l->in.op == UNARY CALL) &&
1338 		    l->in.type != INT && l->in.type != UNSIGNED )
1339 			return;
1340 
1341 		/* Only trust it to get it right if the size is the same */
1342 		if( tlen(p) != tlen(l) )
1343 			return;
1344 
1345 		/* clobber conversion */
1346 		if( l->in.op != FLD )
1347 			l->in.type = p->in.type;
1348 		ncopy( p, l );
1349 		l->in.op = FREE;
1350 
1351 		break;
1352 
1353 	case ASSIGN:
1354 		/*
1355 		 * Conversions are equivalent to assignments;
1356 		 * when the two operations are combined,
1357 		 * we can sometimes zap the conversion.
1358 		 */
1359 		r = p->in.right;
1360 		l = p->in.left;
1361 		if ( r->in.op == SCONV &&
1362 		     !mixtypes(l, r) &&
1363 		     l->in.op != FLD &&
1364 		     tlen(l) == tlen(r) ) {
1365 				p->in.right = r->in.left;
1366 				r->in.op = FREE;
1367 			}
1368 		break;
1369 
1370 	case ULE:
1371 	case ULT:
1372 	case UGE:
1373 	case UGT:
1374 		p->in.op -= (UGE-GE);
1375 		if( degenerate(p) )
1376 			break;
1377 		p->in.op += (UGE-GE);
1378 		break;
1379 
1380 	case EQ:
1381 	case NE:
1382 	case LE:
1383 	case LT:
1384 	case GE:
1385 	case GT:
1386 		if( p->in.left->in.op == SCONV &&
1387 		    p->in.right->in.op == SCONV ) {
1388 			l = p->in.left;
1389 			r = p->in.right;
1390 			if( l->in.type == DOUBLE &&
1391 			    l->in.left->in.type == FLOAT &&
1392 			    r->in.left->in.type == FLOAT ) {
1393 				/* nuke the conversions */
1394 				p->in.left = l->in.left;
1395 				p->in.right = r->in.left;
1396 				l->in.op = FREE;
1397 				r->in.op = FREE;
1398 				}
1399 			/* more? */
1400 			}
1401 		(void) degenerate(p);
1402 		break;
1403 
1404 	case DIV:
1405 		if( p->in.right->in.op == ICON &&
1406 		    p->in.right->tn.name[0] == '\0' &&
1407 		    ISUNSIGNED(p->in.right->in.type) &&
1408 		    (unsigned) p->in.right->tn.lval >= 0x80000000 ) {
1409 			/* easy to do here, harder to do in zzzcode() */
1410 			p->in.op = UGE;
1411 			break;
1412 			}
1413 	case MOD:
1414 	case ASG DIV:
1415 	case ASG MOD:
1416 		/*
1417 		 * optimize DIV and MOD
1418 		 *
1419 		 * basically we spot UCHAR and USHORT and try to do them
1420 		 * as signed ints...  apparently div+mul+sub is always
1421 		 * faster than ediv for finding MOD on the VAX, when
1422 		 * full unsigned MOD isn't needed.
1423 		 *
1424 		 * a curious fact: for MOD, cmp+sub and cmp+sub+cmp+sub
1425 		 * are faster for unsigned dividend and a constant divisor
1426 		 * in the right range (.5 to 1 of dividend's range for the
1427 		 * first, .333+ to .5 for the second).  full unsigned is
1428 		 * already done cmp+sub in the appropriate case; the
1429 		 * other cases are less common and require more ambition.
1430 		 */
1431 		if( degenerate(p) )
1432 			break;
1433 		l = p->in.left;
1434 		r = p->in.right;
1435 		if( !ISUNSIGNED(r->in.type) ||
1436 		    tlen(l) >= SZINT/SZCHAR ||
1437 		    !(tlen(r) < SZINT/SZCHAR ||
1438 		      (r->in.op == ICON && r->tn.name[0] == '\0')) )
1439 			break;
1440 		if( r->in.op == ICON )
1441 			r->tn.type = INT;
1442 		else {
1443 			NODE *t = talloc();
1444 			t->in.left = r;
1445 			r = t;
1446 			r->in.op = SCONV;
1447 			r->in.type = INT;
1448 			r->in.right = 0;
1449 			p->in.right = r;
1450 			}
1451 		if( o == DIV || o == MOD ) {
1452 			NODE *t = talloc();
1453 			t->in.left = l;
1454 			l = t;
1455 			l->in.op = SCONV;
1456 			l->in.type = INT;
1457 			l->in.right = 0;
1458 			p->in.left = l;
1459 			}
1460 		/* handle asgops in table */
1461 		break;
1462 
1463 	case RS:
1464 	case ASG RS:
1465 	case LS:
1466 	case ASG LS:
1467 		/* pick up degenerate shifts */
1468 		l = p->in.left;
1469 		r = p->in.right;
1470 		if( !(r->in.op == ICON && r->tn.name[0] == '\0') )
1471 			break;
1472 		i = r->tn.lval;
1473 		if( i < 0 )
1474 			/* front end 'fixes' this? */
1475 			if( o == LS || o == ASG LS )
1476 				o += (RS-LS);
1477 			else
1478 				o += (LS-RS);
1479 		if( (o == RS || o == ASG RS) &&
1480 		    !ISUNSIGNED(l->in.type) )
1481 			/* can't optimize signed right shifts */
1482 			break;
1483 		if( o == LS ) {
1484 			if( i < SZINT )
1485 				break;
1486 			}
1487 		else {
1488 			if( i < tlen(l) * SZCHAR )
1489 				break;
1490 			}
1491 	zero:
1492 		if( !asgop( o ) )
1493 			if( tshape(l, SAREG|SNAME|SCON|SOREG|STARNM) ) {
1494 				/* no side effects */
1495 				tfree(l);
1496 				ncopy(p, r);
1497 				r->in.op = FREE;
1498 				p->tn.lval = 0;
1499 				}
1500 			else {
1501 				p->in.op = COMOP;
1502 				r->tn.lval = 0;
1503 				}
1504 		else {
1505 			p->in.op = ASSIGN;
1506 			r->tn.lval = 0;
1507 			}
1508 		break;
1509 		}
1510 	}
1511 
1512 degenerate(p) register NODE *p; {
1513 	int o;
1514 	int result, i;
1515 	int lower, upper;
1516 	register NODE *l, *r;
1517 
1518 	/*
1519 	 * try to keep degenerate comparisons with constants
1520 	 * out of the table.
1521 	 */
1522 	r = p->in.right;
1523 	l = p->in.left;
1524 	if( r->in.op != ICON ||
1525 	    r->tn.name[0] != '\0' ||
1526 	    tlen(l) >= tlen(r) )
1527 		return (0);
1528 	switch( l->in.type ) {
1529 	case CHAR:
1530 		lower = -(1 << SZCHAR - 1);
1531 		upper = (1 << SZCHAR - 1) - 1;
1532 		break;
1533 	case UCHAR:
1534 		lower = 0;
1535 		upper = (1 << SZCHAR) - 1;
1536 		break;
1537 	case SHORT:
1538 		lower = -(1 << SZSHORT - 1);
1539 		upper = (1 << SZSHORT - 1) - 1;
1540 		break;
1541 	case USHORT:
1542 		lower = 0;
1543 		upper = (1 << SZSHORT) - 1;
1544 		break;
1545 	default:
1546 		cerror("unsupported type in degenerate()");
1547 		}
1548 	i = r->tn.lval;
1549 	switch( o = p->in.op ) {
1550 	case DIV:
1551 	case ASG DIV:
1552 	case MOD:
1553 	case ASG MOD:
1554 		/* DIV and MOD work like EQ */
1555 	case EQ:
1556 	case NE:
1557 		if( lower == 0 && (unsigned) i > upper )
1558 			result = o == NE;
1559 		else if( i < lower || i > upper )
1560 			result = o == NE;
1561 		else
1562 			return (0);
1563 		break;
1564 	case LT:
1565 	case GE:
1566 		if( lower == 0 && (unsigned) i > upper )
1567 			result = o == LT;
1568 		else if( i <= lower )
1569 			result = o != LT;
1570 		else if( i > upper )
1571 			result = o == LT;
1572 		else
1573 			return (0);
1574 		break;
1575 	case LE:
1576 	case GT:
1577 		if( lower == 0 && (unsigned) i >= upper )
1578 			result = o == LE;
1579 		else if( i < lower )
1580 			result = o != LE;
1581 		else if( i >= upper )
1582 			result = o == LE;
1583 		else
1584 			return (0);
1585 		break;
1586 	default:
1587 		cerror("unknown op in degenerate()");
1588 		}
1589 
1590 	if( o == MOD || o == ASG MOD ) {
1591 		r->in.op = FREE;
1592 		ncopy(p, l);
1593 		l->in.op = FREE;
1594 		}
1595 	else if( o != ASG DIV && tshape(l, SAREG|SNAME|SCON|SOREG|STARNM) ) {
1596 		/* no side effects */
1597 		tfree(l);
1598 		ncopy(p, r);
1599 		r->in.op = FREE;
1600 		p->tn.lval = result;
1601 		}
1602 	else {
1603 		if( o == ASG DIV )
1604 			p->in.op = ASSIGN;
1605 		else {
1606 			p->in.op = COMOP;
1607 			r->tn.type = INT;
1608 			}
1609 		r->tn.lval = result;
1610 		}
1611 	if( logop(o) )
1612 		p->in.type = INT;
1613 
1614 	return (1);
1615 	}
1616 
1617 /* added by jwf */
1618 struct functbl {
1619 	int fop;
1620 	TWORD ftype;
1621 	char *func;
1622 	} opfunc[] = {
1623 	DIV,		TANY,	"udiv",
1624 	MOD,		TANY,	"urem",
1625 	ASG DIV,	TANY,	"audiv",
1626 	ASG MOD,	TANY,	"aurem",
1627 	0,	0,	0 };
1628 
1629 hardops(p)  register NODE *p; {
1630 	/* change hard to do operators into function calls.  */
1631 	register NODE *q;
1632 	register struct functbl *f;
1633 	register o;
1634 	NODE *old,*temp;
1635 
1636 	o = p->in.op;
1637 	if( ! (optype(o)==BITYPE &&
1638 	       (ISUNSIGNED(p->in.left->in.type) ||
1639 		ISUNSIGNED(p->in.right->in.type))) )
1640 		return;
1641 
1642 	for( f=opfunc; f->fop; f++ ) {
1643 		if( o==f->fop ) goto convert;
1644 		}
1645 	return;
1646 
1647 	convert:
1648 	if( p->in.right->in.op == ICON && p->in.right->tn.name[0] == '\0' )
1649 		/* 'J', 'K' in zzzcode() -- assumes DIV or MOD operations */
1650 		/* save a subroutine call -- use at most 5 instructions */
1651 		return;
1652 	if( tlen(p->in.left) < SZINT/SZCHAR && tlen(p->in.right) < SZINT/SZCHAR )
1653 		/* optim2() will modify the op into an ordinary int op */
1654 		return;
1655 	if( asgop( o ) ) {
1656 		old = NIL;
1657 		switch( p->in.left->in.op ){
1658 		case FLD:
1659 			q = p->in.left->in.left;
1660 			/*
1661 			 * rewrite (lval.fld /= rval); as
1662 			 *  ((*temp).fld = udiv((*(temp = &lval)).fld,rval));
1663 			 * else the compiler will evaluate lval twice.
1664 			 */
1665 			if( q->in.op == UNARY MUL ){
1666 				/* first allocate a temp storage */
1667 				temp = talloc();
1668 				temp->in.op = OREG;
1669 				temp->tn.rval = TMPREG;
1670 				temp->tn.lval = BITOOR(freetemp(1));
1671 				temp->in.type = INCREF(p->in.type);
1672 #ifdef FLEXNAMES
1673 				temp->in.name = "";
1674 #else
1675 				temp->in.name[0] = '\0';
1676 #endif
1677 				old = q->in.left;
1678 				q->in.left = temp;
1679 			}
1680 			/* fall thru ... */
1681 
1682 		case REG:
1683 		case NAME:
1684 		case OREG:
1685 			/* change ASG OP to a simple OP */
1686 			q = talloc();
1687 			q->in.op = NOASG p->in.op;
1688 			q->in.rall = NOPREF;
1689 			q->in.type = p->in.type;
1690 			q->in.left = tcopy(p->in.left);
1691 			q->in.right = p->in.right;
1692 			p->in.op = ASSIGN;
1693 			p->in.right = q;
1694 			p = q;
1695 			f -= 2; /* Note: this depends on the table order */
1696 			/* on the right side only - replace *temp with
1697 			 *(temp = &lval), build the assignment node */
1698 			if( old ){
1699 				temp = q->in.left->in.left; /* the "*" node */
1700 				q = talloc();
1701 				q->in.op = ASSIGN;
1702 				q->in.left = temp->in.left;
1703 				q->in.right = old;
1704 				q->in.type = old->in.type;
1705 #ifdef FLEXNAMES
1706 				q->in.name = "";
1707 #else
1708 				q->in.name[0] = '\0';
1709 #endif
1710 				temp->in.left = q;
1711 			}
1712 			break;
1713 
1714 		case UNARY MUL:
1715 			/* avoid doing side effects twice */
1716 			q = p->in.left;
1717 			p->in.left = q->in.left;
1718 			q->in.op = FREE;
1719 			break;
1720 
1721 		default:
1722 			cerror( "hardops: can't compute & LHS" );
1723 			}
1724 		}
1725 
1726 	/* build comma op for args to function */
1727 	q = talloc();
1728 	q->in.op = CM;
1729 	q->in.rall = NOPREF;
1730 	q->in.type = INT;
1731 	q->in.left = p->in.left;
1732 	q->in.right = p->in.right;
1733 	p->in.op = CALL;
1734 	p->in.right = q;
1735 
1736 	/* put function name in left node of call */
1737 	p->in.left = q = talloc();
1738 	q->in.op = ICON;
1739 	q->in.rall = NOPREF;
1740 	q->in.type = INCREF( FTN + p->in.type );
1741 #ifndef FLEXNAMES
1742 	strcpy( q->in.name, f->func );
1743 #else
1744 	q->in.name = f->func;
1745 #endif
1746 	q->tn.lval = 0;
1747 	q->tn.rval = 0;
1748 
1749 	}
1750 
1751 zappost(p) NODE *p; {
1752 	/* look for ++ and -- operators and remove them */
1753 
1754 	register int o, ty;
1755 	register NODE *q;
1756 	o = p->in.op;
1757 	ty = optype( o );
1758 
1759 	switch( o ){
1760 
1761 	case INCR:
1762 	case DECR:
1763 			q = p->in.left;
1764 			p->in.right->in.op = FREE;  /* zap constant */
1765 			ncopy( p, q );
1766 			q->in.op = FREE;
1767 			return;
1768 
1769 		}
1770 
1771 	if( ty == BITYPE ) zappost( p->in.right );
1772 	if( ty != LTYPE ) zappost( p->in.left );
1773 }
1774 
1775 fixpre(p) NODE *p; {
1776 
1777 	register int o, ty;
1778 	o = p->in.op;
1779 	ty = optype( o );
1780 
1781 	switch( o ){
1782 
1783 	case ASG PLUS:
1784 			p->in.op = PLUS;
1785 			break;
1786 	case ASG MINUS:
1787 			p->in.op = MINUS;
1788 			break;
1789 		}
1790 
1791 	if( ty == BITYPE ) fixpre( p->in.right );
1792 	if( ty != LTYPE ) fixpre( p->in.left );
1793 }
1794 
1795 /*ARGSUSED*/
1796 NODE * addroreg(l) NODE *l;
1797 				/* OREG was built in clocal()
1798 				 * for an auto or formal parameter
1799 				 * now its address is being taken
1800 				 * local code must unwind it
1801 				 * back to PLUS/MINUS REG ICON
1802 				 * according to local conventions
1803 				 */
1804 {
1805 	cerror("address of OREG taken");
1806 	/*NOTREACHED*/
1807 }
1808 
1809 
1810 
1811 # ifndef ONEPASS
1812 main( argc, argv ) char *argv[]; {
1813 	return( mainp2( argc, argv ) );
1814 	}
1815 # endif
1816 
1817 strip(p) register NODE *p; {
1818 	NODE *q;
1819 
1820 	/* strip nodes off the top when no side effects occur */
1821 	for( ; ; ) {
1822 		switch( p->in.op ) {
1823 		case SCONV:			/* remove lint tidbits */
1824 			q = p->in.left;
1825 			ncopy( p, q );
1826 			q->in.op = FREE;
1827 			break;
1828 		/* could probably add a few more here */
1829 		default:
1830 			return;
1831 			}
1832 		}
1833 	}
1834 
1835 myreader(p) register NODE *p; {
1836 	strip( p );		/* strip off operations with no side effects */
1837 	canon( p );		/* expands r-vals for fields */
1838 	walkf( p, hardops );	/* convert ops to function calls */
1839 	walkf( p, optim2 );
1840 	}
1841