xref: /csrg-svn/old/pcc/ccom.vax/local2.c (revision 32940)
1 # ifndef lint
2 static char *sccsid ="@(#)local2.c	1.34 (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 	p->tn.lval = szty(ty) * (SZINT/SZCHAR);
472 	q->in.right = p;
473 	p = talloc();
474 	p->in.op = UNARY MUL;
475 	p->in.left = q;
476 	return( p );
477 	}
478 
479 sconv( p, forarg ) register NODE *p; {
480 	register NODE *l, *r;
481 	int m, val;
482 
483 	if (xdebug) eprint(p, 0, &val, &val);
484 	r = getlr(p, 'R');
485 	if (p->in.op == ASSIGN)
486 		l = getlr(p, 'L');
487 	else if (p->in.op == SCONV) {
488 		m = r->in.type;
489 		if (forarg)
490 			l = makearg( m );
491 		else
492 			l = resc;
493 		l->in.type = m;
494 		r = getlr(p, 'L');
495 		}
496 	else {		/* OPLTYPE */
497 		m = (r->in.type==FLOAT || r->in.type==DOUBLE ? r->in.type : INT);
498 		if (forarg)
499 			l = makearg( m );
500 		else
501 			l = resc;
502 		l->in.type = m;
503 		}
504 	if (r->in.op == ICON)
505 		if (r->in.name[0] == '\0') {
506 			if (r->tn.lval == 0 && !forarg) {
507 				putstr("clr");
508 				prtype(l);
509 				putchar('\t');
510 				adrput(l);
511 				goto cleanup;
512 				}
513 			if (r->tn.lval < 0 && r->tn.lval >= -63) {
514 				putstr("mneg");
515 				prtype(l);
516 				r->tn.lval = -r->tn.lval;
517 				goto ops;
518 				}
519 			if (r->tn.lval < 0)
520 				r->in.type = r->tn.lval >= -128 ? CHAR
521 					: (r->tn.lval >= -32768 ? SHORT
522 					: INT);
523 			else if (l->in.type == FLOAT ||
524 			    l->in.type == DOUBLE)
525 				r->in.type = r->tn.lval <= 63 ? INT
526 					: (r->tn.lval <= 127 ? CHAR
527 					: (r->tn.lval <= 32767 ? SHORT
528 					: INT));
529 			else
530 				r->in.type = r->tn.lval <= 63 ? INT
531 					: (r->tn.lval <= 127 ? CHAR
532 					: (r->tn.lval <= 255 ? UCHAR
533 					: (r->tn.lval <= 32767 ? SHORT
534 					: (r->tn.lval <= 65535 ? USHORT
535 					: INT))));
536 			if (forarg && r->in.type == INT) {
537 				putstr("pushl\t");
538 				adrput(r);
539 				goto cleanup;
540 				}
541 			}
542 		else {
543 			if (forarg && tlen(r) == SZINT/SZCHAR) {
544 				putstr("pushl\t");
545 				adrput(r);
546 				goto cleanup;
547 				}
548 			putstr("moval\t");
549 			acon(r);
550 			putchar(',');
551 			adrput(l);
552 			goto cleanup;
553 			}
554 
555 	if (p->in.op == SCONV &&
556 	    !(l->in.type == FLOAT || l->in.type == DOUBLE) &&
557 	    !mixtypes(l, r)) {
558 		/*
559 		 * Because registers must always contain objects
560 		 * of the same width as INTs, we may have to
561 		 * perform two conversions to get an INT.  Can
562 		 * the conversions be collapsed into one?
563 		 */
564 		if (m = collapsible(l, r))
565 			r->in.type = m;
566 		else {
567 			/*
568 			 * Two steps are required.
569 			 */
570 			NODE *x;
571 
572 			if (forarg) {
573 				x = resc;
574 				x->in.type = l->in.type;
575 				}
576 			else {
577 				x = &resc[1];
578 				*x = *l;
579 				}
580 
581 			if (tlen(x) > tlen(r) && ISUNSIGNED(r->in.type))
582 				putstr("movz");
583 			else
584 				putstr("cvt");
585 			prtype(r);
586 			prtype(x);
587 			putchar('\t');
588 			adrput(r);
589 			putchar(',');
590 			adrput(x);
591 			putchar('\n');
592 			putchar('\t');
593 			r = x;
594 			}
595 		l->in.type = (ISUNSIGNED(l->in.type) ? UNSIGNED : INT);
596 		}
597 
598 	if ((r->in.type == UNSIGNED || r->in.type == ULONG) &&
599 	    mixtypes(l, r)) {
600 		int label1, label2;
601 		NODE *x = NULL;
602 
603 #if defined(FORT) || defined(SPRECC)
604 		if (forarg)
605 #else
606 		if (forarg || l == resc)
607 #endif
608 			{
609 			/* compute in register, convert to double when done */
610 			x = l;
611 			l = resc;
612 			l->in.type = x->in.type;
613 			}
614 
615 		label1 = getlab();
616 		label2 = getlab();
617 
618 		putstr("movl\t");
619 		adrput(r);
620 		putchar(',');
621 		adrput(l);
622 		putstr("\n\tjbsc\t$31,");
623 		adrput(l);
624 		printf(",L%d\n\tcvtl", label1);
625 		prtype(l);
626 		putchar('\t');
627 		adrput(l);
628 		putchar(',');
629 		adrput(l);
630 		printf("\n\tjbr\tL%d\nL%d:\n\tcvtl", label2, label1);
631 		prtype(l);
632 		putchar('\t');
633 		adrput(l);
634 		putchar(',');
635 		adrput(l);
636 		putstr("\n\tadd");
637 		prtype(l);
638 		putstr("2\t$0");
639 		prtype(l);
640 		putstr("2.147483648e9,");
641 		adrput(l);
642 		printf("\nL%d:", label2);
643 
644 		if (!forarg && (l->in.type == DOUBLE || l != resc))
645 			goto cleanup;
646 		if (x != NULL) {
647 			if (l == x) {
648 				r = &resc[1];
649 				*r = *l;
650 				}
651 			else {
652 				r = l;
653 				l = x;
654 				}
655 			l->in.type = DOUBLE;
656 			}
657 		putstr("\n\t");
658 		}
659 
660 	if( (l->in.type == FLOAT || l->in.type == DOUBLE) &&
661 	    (r->in.type == UCHAR || r->in.type == USHORT) ) {
662 		/* skip unnecessary unsigned to floating conversion */
663 #if defined(FORT) || defined(SPRECC)
664 		if (forarg)
665 #else
666 		if (forarg || l == resc)
667 #endif
668 			l->in.type = DOUBLE;
669 		putstr("movz");
670 		prtype(r);
671 		putstr("l\t");
672 		adrput(r);
673 		putchar(',');
674 		adrput(resc);
675 		putstr("\n\t");
676 		if (l == resc) {
677 			r = &resc[1];
678 			*r = *l;
679 			}
680 		else
681 			r = resc;
682 		r->in.type = INT;
683 		}
684 
685 #if defined(FORT) || defined(SPRECC)
686 	if (forarg && l->in.type == FLOAT)
687 #else
688 	if ((forarg || l == resc) && l->in.type == FLOAT)
689 #endif
690 		{
691 		/* perform an implicit conversion to double */
692 		l->in.type = DOUBLE;
693 		if (r->in.type != FLOAT &&
694 		    r->in.type != CHAR &&
695 		    r->in.type != SHORT) {
696 			/* trim bits from the mantissa */
697 			putstr("cvt");
698 			prtype(r);
699 			putstr("f\t");
700 			adrput(r);
701 			putchar(',');
702 			adrput(resc);
703 			putstr("\n\t");
704 			if (l == resc) {
705 				r = &resc[1];
706 				*r = *l;
707 				}
708 			else
709 				r = resc;
710 			r->in.type = FLOAT;
711 			}
712 		}
713 
714 	if (!mixtypes(l,r)) {
715 		if (tlen(l) == tlen(r)) {
716 			if (forarg && tlen(l) == SZINT/SZCHAR) {
717 				putstr("pushl\t");
718 				adrput(r);
719 				goto cleanup;
720 				}
721 			putstr("mov");
722 #ifdef FORT
723 			if (Oflag)
724 				prtype(l);
725 			else {
726 				if (l->in.type == DOUBLE)
727 					putchar('q');
728 				else if(l->in.type == FLOAT)
729 					putchar('l');
730 				else
731 					prtype(l);
732 				}
733 #else
734 			prtype(l);
735 #endif FORT
736 			goto ops;
737 			}
738 		else if (tlen(l) > tlen(r) && ISUNSIGNED(r->in.type))
739 			putstr("movz");
740 		else
741 			putstr("cvt");
742 		}
743 	else
744 		putstr("cvt");
745 	prtype(r);
746 	prtype(l);
747 ops:
748 	putchar('\t');
749 	adrput(r);
750 	putchar(',');
751 	adrput(l);
752 
753 cleanup:
754 	if (forarg)
755 		tfree(l);
756 	}
757 
758 /*
759  * collapsible(dest, src) -- if a conversion with a register destination
760  *	can be accomplished in one instruction, return the type of src
761  *	that will do the job correctly; otherwise return 0.  Note that
762  *	a register must always end up having type INT or UNSIGNED.
763  */
764 int
765 collapsible(dest, src)
766 NODE *dest, *src;
767 {
768 	int st = src->in.type;
769 	int dt = dest->in.type;
770 	int newt = 0;
771 
772 	/*
773 	 * Are there side effects of evaluating src?
774 	 * If the derived type will not be the same size as src,
775 	 * we may have to use two steps.
776 	 */
777 	if (tlen(src) > tlen(dest)) {
778 		if (tshape(src, STARREG))
779 			return (0);
780 		if (src->in.op == OREG && R2TEST(src->tn.rval))
781 			return (0);
782 		}
783 
784 	/*
785 	 * Can we get an object of dest's type by punning src?
786 	 * Praises be to great Cthulhu for little-endian machines...
787 	 */
788 	if (st == CHAR && dt == USHORT)
789 		/*
790 		 * Special case -- we must sign-extend to 16 bits.
791 		 */
792 		return (0);
793 
794 	if (tlen(src) < tlen(dest))
795 		newt = st;
796 	else
797 		newt = dt;
798 
799 	return (newt);
800 	}
801 
802 rmove( rt, rs, t ) TWORD t; {
803 	printf( "	%s	%s,%s\n",
804 #ifdef FORT
805 		!Oflag ? (t==DOUBLE ? "movq" : "movl") :
806 #endif
807 		(t==FLOAT ? "movf" : (t==DOUBLE ? "movd" : "movl")),
808 		rnames[rs], rnames[rt] );
809 	}
810 
811 struct respref
812 respref[] = {
813 	INTAREG|INTBREG,	INTAREG|INTBREG,
814 	INAREG|INBREG,	INAREG|INBREG|SOREG|STARREG|STARNM|SNAME|SCON,
815 	INTEMP,	INTEMP,
816 	FORARG,	FORARG,
817 	INTEMP,	INTAREG|INAREG|INTBREG|INBREG|SOREG|STARREG|STARNM,
818 	0,	0 };
819 
820 setregs(){ /* set up temporary registers */
821 	fregs = 6;	/* tbl- 6 free regs on VAX (0-5) */
822 	}
823 
824 /*ARGSUSED*/
825 rewfld( p ) NODE *p; {
826 	return(1);
827 	}
828 
829 /*ARGSUSED*/
830 callreg(p) NODE *p; {
831 	return( R0 );
832 	}
833 
834 base( p ) register NODE *p; {
835 	register int o = p->in.op;
836 
837 	if( o==ICON && p->tn.name[0] != '\0' ) return( 100 ); /* ie no base reg */
838 	if( o==REG ) return( p->tn.rval );
839     if( (o==PLUS || o==MINUS) && p->in.left->in.op == REG && p->in.right->in.op==ICON)
840 		return( p->in.left->tn.rval );
841     if( o==OREG && !R2TEST(p->tn.rval) && (p->in.type==INT || p->in.type==UNSIGNED || ISPTR(p->in.type)) )
842 		return( p->tn.rval + 0200*1 );
843 	if( o==INCR && p->in.left->in.op==REG ) return( p->in.left->tn.rval + 0200*2 );
844 	if( o==ASG MINUS && p->in.left->in.op==REG) return( p->in.left->tn.rval + 0200*4 );
845 	if( o==UNARY MUL && p->in.left->in.op==INCR && p->in.left->in.left->in.op==REG
846 	  && (p->in.type==INT || p->in.type==UNSIGNED || ISPTR(p->in.type)) )
847 		return( p->in.left->in.left->tn.rval + 0200*(1+2) );
848 	if( o==NAME ) return( 100 + 0200*1 );
849 	return( -1 );
850 	}
851 
852 offset( p, tyl ) register NODE *p; int tyl; {
853 
854 	if( tyl==1 &&
855 	    p->in.op==REG &&
856 	    (p->in.type==INT || p->in.type==UNSIGNED) )
857 		return( p->tn.rval );
858 	if( p->in.op==LS &&
859 	    p->in.left->in.op==REG &&
860 	    (p->in.left->in.type==INT || p->in.left->in.type==UNSIGNED) &&
861 	    p->in.right->in.op==ICON &&
862 	    p->in.right->in.name[0]=='\0' &&
863 	    (1<<p->in.right->tn.lval)==tyl)
864 		return( p->in.left->tn.rval );
865 	if( tyl==2 &&
866 	    p->in.op==PLUS &&
867 	    (p->in.left->in.type==INT || p->in.left->in.type==UNSIGNED) &&
868 	    p->in.left->in.op==REG &&
869 	    p->in.right->in.op==REG &&
870 	    p->in.left->tn.rval==p->in.right->tn.rval )
871 		return( p->in.left->tn.rval );
872 	return( -1 );
873 	}
874 
875 makeor2( p, q, b, o) register NODE *p, *q; register int b, o; {
876 	register NODE *t;
877 	NODE *f;
878 
879 	p->in.op = OREG;
880 	f = p->in.left; 	/* have to free this subtree later */
881 
882 	/* init base */
883 	switch (q->in.op) {
884 		case ICON:
885 		case REG:
886 		case OREG:
887 		case NAME:
888 			t = q;
889 			break;
890 
891 		case MINUS:
892 			q->in.right->tn.lval = -q->in.right->tn.lval;
893 		case PLUS:
894 			t = q->in.right;
895 			break;
896 
897 		case INCR:
898 		case ASG MINUS:
899 			t = q->in.left;
900 			break;
901 
902 		case UNARY MUL:
903 			t = q->in.left->in.left;
904 			break;
905 
906 		default:
907 			cerror("illegal makeor2");
908 	}
909 
910 	p->tn.lval = t->tn.lval;
911 #ifndef FLEXNAMES
912 	{
913 		register int i;
914 		for(i=0; i<NCHNAM; ++i)
915 			p->in.name[i] = t->in.name[i];
916 	}
917 #else
918 	p->in.name = t->in.name;
919 #endif
920 
921 	/* init offset */
922 	p->tn.rval = R2PACK( (b & 0177), o, (b>>7) );
923 
924 	tfree(f);
925 	return;
926 	}
927 
928 canaddr( p ) NODE *p; {
929 	register int o = p->in.op;
930 
931 	if( o==NAME || o==REG || o==ICON || o==OREG || (o==UNARY MUL && shumul(p->in.left)) ) return(1);
932 	return(0);
933 	}
934 
935 flshape( p ) NODE *p; {
936 	register int o = p->in.op;
937 
938 	return( o == REG || o == NAME || o == ICON ||
939 		(o == OREG && (!R2TEST(p->tn.rval) || tlen(p) == 1)) );
940 	}
941 
942 /* INTEMP shapes must not contain any temporary registers */
943 shtemp( p ) register NODE *p; {
944 	int r;
945 
946 	if( p->in.op == STARG ) p = p->in.left;
947 
948 	switch (p->in.op) {
949 	case REG:
950 		return( !istreg(p->tn.rval) );
951 	case OREG:
952 		r = p->tn.rval;
953 		if( R2TEST(r) ) {
954 			if( istreg(R2UPK1(r)) )
955 				return(0);
956 			r = R2UPK2(r);
957 			}
958 		return( !istreg(r) );
959 	case UNARY MUL:
960 		p = p->in.left;
961 		return( p->in.op != UNARY MUL && shtemp(p) );
962 		}
963 
964 	if( optype( p->in.op ) != LTYPE ) return(0);
965 	return(1);
966 	}
967 
968 shumul( p ) register NODE *p; {
969 	register int o;
970 	extern int xdebug;
971 
972 	if (xdebug) {
973 		int val;
974 		printf("shumul:\n");
975 		eprint(p, 0, &val, &val);
976 		}
977 
978 	o = p->in.op;
979 	if( o == NAME || (o == OREG && !R2TEST(p->tn.rval)) || o == ICON ) return( STARNM );
980 
981 	if( ( o == INCR || o == ASG MINUS ) &&
982 	    ( p->in.left->in.op == REG && p->in.right->in.op == ICON ) &&
983 	    p->in.right->in.name[0] == '\0' )
984 		{
985 		switch (p->in.type)
986 			{
987 			case CHAR|PTR:
988 			case UCHAR|PTR:
989 				o = 1;
990 				break;
991 
992 			case SHORT|PTR:
993 			case USHORT|PTR:
994 				o = 2;
995 				break;
996 
997 			case INT|PTR:
998 			case UNSIGNED|PTR:
999 			case LONG|PTR:
1000 			case ULONG|PTR:
1001 			case FLOAT|PTR:
1002 				o = 4;
1003 				break;
1004 
1005 			case DOUBLE|PTR:
1006 				o = 8;
1007 				break;
1008 
1009 			default:
1010 				if ( ISPTR(p->in.type) &&
1011 				     ISPTR(DECREF(p->in.type)) ) {
1012 					o = 4;
1013 					break;
1014 					}
1015 				else return(0);
1016 			}
1017 		return( p->in.right->tn.lval == o ? STARREG : 0);
1018 		}
1019 
1020 	return( 0 );
1021 	}
1022 
1023 adrcon( val ) CONSZ val; {
1024 	putchar( '$' );
1025 	printf( CONFMT, val );
1026 	}
1027 
1028 conput( p ) register NODE *p; {
1029 	switch( p->in.op ){
1030 
1031 	case ICON:
1032 		acon( p );
1033 		return;
1034 
1035 	case REG:
1036 		putstr( rnames[p->tn.rval] );
1037 		return;
1038 
1039 	default:
1040 		cerror( "illegal conput" );
1041 		}
1042 	}
1043 
1044 /*ARGSUSED*/
1045 insput( p ) NODE *p; {
1046 	cerror( "insput" );
1047 	}
1048 
1049 upput( p, size ) NODE *p; int size; {
1050 	if( size == SZLONG && p->in.op == REG ) {
1051 		putstr( rnames[p->tn.rval + 1] );
1052 		return;
1053 		}
1054 	cerror( "upput" );
1055 	}
1056 
1057 adrput( p ) register NODE *p; {
1058 	register int r;
1059 	/* output an address, with offsets, from p */
1060 
1061 	if( p->in.op == FLD ){
1062 		p = p->in.left;
1063 		}
1064 	switch( p->in.op ){
1065 
1066 	case NAME:
1067 		acon( p );
1068 		return;
1069 
1070 	case ICON:
1071 		/* addressable value of the constant */
1072 		putchar( '$' );
1073 		acon( p );
1074 		return;
1075 
1076 	case REG:
1077 		putstr( rnames[p->tn.rval] );
1078 		return;
1079 
1080 	case OREG:
1081 		r = p->tn.rval;
1082 		if( R2TEST(r) ){ /* double indexing */
1083 			register int flags;
1084 
1085 			flags = R2UPK3(r);
1086 			if( flags & 1 ) putchar('*');
1087 			if( flags & 4 ) putchar('-');
1088 			if( p->tn.lval != 0 || p->in.name[0] != '\0' ) acon(p);
1089 			if( R2UPK1(r) != 100) printf( "(%s)", rnames[R2UPK1(r)] );
1090 			if( flags & 2 ) putchar('+');
1091 			printf( "[%s]", rnames[R2UPK2(r)] );
1092 			return;
1093 			}
1094 		if( r == AP ){  /* in the argument region */
1095 			if( p->in.name[0] != '\0' ) werror( "bad arg temp" );
1096 			printf( CONFMT, p->tn.lval );
1097 			putstr( "(ap)" );
1098 			return;
1099 			}
1100 		if( p->tn.lval != 0 || p->in.name[0] != '\0') acon( p );
1101 		printf( "(%s)", rnames[p->tn.rval] );
1102 		return;
1103 
1104 	case UNARY MUL:
1105 		/* STARNM or STARREG found */
1106 		if( tshape(p, STARNM) ) {
1107 			putchar( '*' );
1108 			adrput( p->in.left);
1109 			}
1110 		else {	/* STARREG - really auto inc or dec */
1111 			register NODE *q;
1112 
1113 			q = p->in.left;
1114 			if( q->in.right->tn.lval != tlen(p) )
1115 				cerror("adrput: bad auto-increment/decrement");
1116 			printf("%s(%s)%s", (q->in.op==INCR ? "" : "-"),
1117 				rnames[q->in.left->tn.rval],
1118 				(q->in.op==INCR ? "+" : "") );
1119 			p->in.op = OREG;
1120 			p->tn.rval = q->in.left->tn.rval;
1121 			p->tn.lval = (q->in.op == INCR ? -q->in.right->tn.lval : 0);
1122 #ifndef FLEXNAMES
1123 			p->in.name[0] = '\0';
1124 #else
1125 			p->in.name = "";
1126 #endif
1127 			tfree(q);
1128 		}
1129 		return;
1130 
1131 	default:
1132 		cerror( "illegal address" );
1133 		return;
1134 
1135 		}
1136 
1137 	}
1138 
1139 acon( p ) register NODE *p; { /* print out a constant */
1140 
1141 	if( p->in.name[0] == '\0' )
1142 		printf( CONFMT, p->tn.lval);
1143 	else {
1144 #ifndef FLEXNAMES
1145 		printf( "%.8s", p->in.name );
1146 #else
1147 		putstr( p->in.name );
1148 #endif
1149 		if( p->tn.lval != 0 ) {
1150 			putchar( '+' );
1151 			printf( CONFMT, p->tn.lval );
1152 			}
1153 		}
1154 	}
1155 
1156 genscall( p, cookie ) register NODE *p; {
1157 	/* structure valued call */
1158 	return( gencall( p, cookie ) );
1159 	}
1160 
1161 /* tbl */
1162 int gc_numbytes;
1163 /* tbl */
1164 
1165 /*ARGSUSED*/
1166 gencall( p, cookie ) register NODE *p; {
1167 	/* generate the call given by p */
1168 	register NODE *p1;
1169 	register int temp, temp1;
1170 	register int m;
1171 
1172 	if( p->in.right ) temp = argsize( p->in.right );
1173 	else temp = 0;
1174 
1175 	if( p->in.op == STCALL || p->in.op == UNARY STCALL ){
1176 		/* set aside room for structure return */
1177 
1178 		if( p->stn.stsize > temp ) temp1 = p->stn.stsize;
1179 		else temp1 = temp;
1180 		}
1181 
1182 	if( temp > maxargs ) maxargs = temp;
1183 	SETOFF(temp1,4);
1184 
1185 	if( p->in.right ){ /* make temp node, put offset in, and generate args */
1186 		genargs( p->in.right );
1187 		}
1188 
1189 	p1 = p->in.left;
1190 	if( p1->in.op != ICON ){
1191 		if( p1->in.op != REG ){
1192 			if( p1->in.op != OREG || R2TEST(p1->tn.rval) ){
1193 				if( p1->in.op != NAME ){
1194 					order( p1, INAREG );
1195 					}
1196 				}
1197 			}
1198 		}
1199 
1200 /* tbl
1201 	setup gc_numbytes so reference to ZC works */
1202 
1203 	gc_numbytes = temp&(0x3ff);
1204 /* tbl */
1205 
1206 	p->in.op = UNARY CALL;
1207 	m = match( p, INTAREG|INTBREG );
1208 
1209 	/* compensate for deficiency in 'ret' instruction ... wah,kre */
1210 	/* (plus in assignment to gc_numbytes above, for neatness only) */
1211 	if (temp >= 1024)
1212 		printf("	addl2	$%d,sp\n", (temp&(~0x3ff)));
1213 
1214 	return(m != MDONE);
1215 	}
1216 
1217 /* tbl */
1218 char *
1219 ccbranches[] = {
1220 	"eql",
1221 	"neq",
1222 	"leq",
1223 	"lss",
1224 	"geq",
1225 	"gtr",
1226 	"lequ",
1227 	"lssu",
1228 	"gequ",
1229 	"gtru",
1230 	};
1231 /* tbl */
1232 
1233 /*ARGSUSED*/
1234 cbgen( o, lab, mode ) { /*   printf conditional and unconditional branches */
1235 
1236 	if( o != 0 && ( o < EQ || o > UGT ) )
1237 		cerror( "bad conditional branch: %s", opst[o] );
1238 	printf( "	j%s	L%d\n", o == 0 ? "br" : ccbranches[o-EQ], lab );
1239 	}
1240 
1241 nextcook( p, cookie ) NODE *p; {
1242 	/* we have failed to match p with cookie; try another */
1243 	if( cookie == FORREW ) return( 0 );  /* hopeless! */
1244 	if( !(cookie&(INTAREG|INTBREG)) ) return( INTAREG|INTBREG );
1245 	if( !(cookie&INTEMP) && asgop(p->in.op) ) return( INTEMP|INAREG|INTAREG|INTBREG|INBREG );
1246 	return( FORREW );
1247 	}
1248 
1249 /*ARGSUSED*/
1250 lastchance( p, cook ) NODE *p; {
1251 	/* forget it! */
1252 	return(0);
1253 	}
1254 
1255 optim2( p ) register NODE *p; {
1256 	/* do local tree transformations and optimizations */
1257 
1258 	int o;
1259 	int i, mask;
1260 	register NODE *l, *r;
1261 
1262 	switch( o = p->in.op ) {
1263 
1264 	case AND:
1265 		/* commute L and R to eliminate complements and constants */
1266 		if( (l = p->in.left)->in.op == ICON && l->in.name[0] == 0 ||
1267 		    l->in.op == COMPL ) {
1268 			p->in.left = p->in.right;
1269 			p->in.right = l;
1270 			}
1271 	case ASG AND:
1272 		/* change meaning of AND to ~R&L - bic on pdp11 */
1273 		r = p->in.right;
1274 		if( r->in.op==ICON && r->in.name[0]==0 ) {
1275 			/* check for degenerate operations */
1276 			l = p->in.left;
1277 			mask = (1 << tlen(l) * SZCHAR) - 1;
1278 			if( ISUNSIGNED(r->in.type) ) {
1279 				i = (~r->tn.lval & mask);
1280 				if( i == 0 ) {
1281 					r->in.op = FREE;
1282 					ncopy(p, l);
1283 					l->in.op = FREE;
1284 					break;
1285 					}
1286 				else if( i == mask )
1287 					goto zero;
1288 				else
1289 					r->tn.lval = i;
1290 				break;
1291 				}
1292 			else if( r->tn.lval == mask &&
1293 				 tlen(l) < SZINT/SZCHAR ) {
1294 				r->in.op = SCONV;
1295 				r->in.left = l;
1296 				r->in.right = 0;
1297 				r->in.type = ENUNSIGN(l->in.type);
1298 				r->in.su = l->in.su > 1 ? l->in.su : 1;
1299 				ncopy(p, r);
1300 				p->in.left = r;
1301 				p->in.type = INT;
1302 				break;
1303 				}
1304 			/* complement constant */
1305 			r->tn.lval = ~r->tn.lval;
1306 			}
1307 		else if( r->in.op==COMPL ) { /* ~~A => A */
1308 			r->in.op = FREE;
1309 			p->in.right = r->in.left;
1310 			}
1311 		else { /* insert complement node */
1312 			p->in.right = l = talloc();
1313 			l->in.op = COMPL;
1314 			l->in.rall = NOPREF;
1315 			l->in.type = r->in.type;
1316 			l->in.left = r;
1317 			l->in.right = NULL;
1318 			}
1319 		break;
1320 
1321 	case SCONV:
1322 		l = p->in.left;
1323 #if defined(FORT) || defined(SPRECC)
1324 		if( p->in.type == FLOAT || p->in.type == DOUBLE ||
1325 		    l->in.type == FLOAT || l->in.type == DOUBLE )
1326 			return;
1327 #else
1328 		if( mixtypes(p, l) ) return;
1329 #endif
1330 		if( l->in.op == PCONV )
1331 			return;
1332 		if( (l->in.op == CALL || l->in.op == UNARY CALL) &&
1333 		    l->in.type != INT && l->in.type != UNSIGNED )
1334 			return;
1335 
1336 		/* Only trust it to get it right if the size is the same */
1337 		if( tlen(p) != tlen(l) )
1338 			return;
1339 
1340 		/* clobber conversion */
1341 		if( l->in.op != FLD )
1342 			l->in.type = p->in.type;
1343 		ncopy( p, l );
1344 		l->in.op = FREE;
1345 
1346 		break;
1347 
1348 	case ASSIGN:
1349 		/*
1350 		 * Conversions are equivalent to assignments;
1351 		 * when the two operations are combined,
1352 		 * we can sometimes zap the conversion.
1353 		 */
1354 		r = p->in.right;
1355 		l = p->in.left;
1356 		if ( r->in.op == SCONV &&
1357 		     !mixtypes(l, r) &&
1358 		     l->in.op != FLD &&
1359 		     tlen(l) == tlen(r) ) {
1360 				p->in.right = r->in.left;
1361 				r->in.op = FREE;
1362 			}
1363 		break;
1364 
1365 	case ULE:
1366 	case ULT:
1367 	case UGE:
1368 	case UGT:
1369 		p->in.op -= (UGE-GE);
1370 		if( degenerate(p) )
1371 			break;
1372 		p->in.op += (UGE-GE);
1373 		break;
1374 
1375 	case EQ:
1376 	case NE:
1377 	case LE:
1378 	case LT:
1379 	case GE:
1380 	case GT:
1381 		if( p->in.left->in.op == SCONV &&
1382 		    p->in.right->in.op == SCONV ) {
1383 			l = p->in.left;
1384 			r = p->in.right;
1385 			if( l->in.type == DOUBLE &&
1386 			    l->in.left->in.type == FLOAT &&
1387 			    r->in.left->in.type == FLOAT ) {
1388 				/* nuke the conversions */
1389 				p->in.left = l->in.left;
1390 				p->in.right = r->in.left;
1391 				l->in.op = FREE;
1392 				r->in.op = FREE;
1393 				}
1394 			/* more? */
1395 			}
1396 		(void) degenerate(p);
1397 		break;
1398 
1399 	case DIV:
1400 		if( p->in.right->in.op == ICON &&
1401 		    p->in.right->tn.name[0] == '\0' &&
1402 		    ISUNSIGNED(p->in.right->in.type) &&
1403 		    (unsigned) p->in.right->tn.lval >= 0x80000000 ) {
1404 			/* easy to do here, harder to do in zzzcode() */
1405 			p->in.op = UGE;
1406 			break;
1407 			}
1408 	case MOD:
1409 	case ASG DIV:
1410 	case ASG MOD:
1411 		/*
1412 		 * optimize DIV and MOD
1413 		 *
1414 		 * basically we spot UCHAR and USHORT and try to do them
1415 		 * as signed ints...  apparently div+mul+sub is always
1416 		 * faster than ediv for finding MOD on the VAX, when
1417 		 * full unsigned MOD isn't needed.
1418 		 *
1419 		 * a curious fact: for MOD, cmp+sub and cmp+sub+cmp+sub
1420 		 * are faster for unsigned dividend and a constant divisor
1421 		 * in the right range (.5 to 1 of dividend's range for the
1422 		 * first, .333+ to .5 for the second).  full unsigned is
1423 		 * already done cmp+sub in the appropriate case; the
1424 		 * other cases are less common and require more ambition.
1425 		 */
1426 		if( degenerate(p) )
1427 			break;
1428 		l = p->in.left;
1429 		r = p->in.right;
1430 		if( !ISUNSIGNED(r->in.type) ||
1431 		    tlen(l) >= SZINT/SZCHAR ||
1432 		    !(tlen(r) < SZINT/SZCHAR ||
1433 		      (r->in.op == ICON && r->tn.name[0] == '\0')) )
1434 			break;
1435 		if( r->in.op == ICON )
1436 			r->tn.type = INT;
1437 		else {
1438 			NODE *t = talloc();
1439 			t->in.left = r;
1440 			r = t;
1441 			r->in.op = SCONV;
1442 			r->in.type = INT;
1443 			r->in.right = 0;
1444 			p->in.right = r;
1445 			}
1446 		if( o == DIV || o == MOD ) {
1447 			NODE *t = talloc();
1448 			t->in.left = l;
1449 			l = t;
1450 			l->in.op = SCONV;
1451 			l->in.type = INT;
1452 			l->in.right = 0;
1453 			p->in.left = l;
1454 			}
1455 		/* handle asgops in table */
1456 		break;
1457 
1458 	case RS:
1459 	case ASG RS:
1460 	case LS:
1461 	case ASG LS:
1462 		/* pick up degenerate shifts */
1463 		l = p->in.left;
1464 		r = p->in.right;
1465 		if( !(r->in.op == ICON && r->tn.name[0] == '\0') )
1466 			break;
1467 		i = r->tn.lval;
1468 		if( i < 0 )
1469 			/* front end 'fixes' this? */
1470 			if( o == LS || o == ASG LS )
1471 				o += (RS-LS);
1472 			else
1473 				o += (LS-RS);
1474 		if( (o == RS || o == ASG RS) &&
1475 		    !ISUNSIGNED(l->in.type) )
1476 			/* can't optimize signed right shifts */
1477 			break;
1478 		if( o == LS ) {
1479 			if( i < SZINT )
1480 				break;
1481 			}
1482 		else {
1483 			if( i < tlen(l) * SZCHAR )
1484 				break;
1485 			}
1486 	zero:
1487 		if( !asgop( o ) )
1488 			if( tshape(l, SAREG|SNAME|SCON|SOREG|STARNM) ) {
1489 				/* no side effects */
1490 				tfree(l);
1491 				ncopy(p, r);
1492 				r->in.op = FREE;
1493 				p->tn.lval = 0;
1494 				}
1495 			else {
1496 				p->in.op = COMOP;
1497 				r->tn.lval = 0;
1498 				}
1499 		else {
1500 			p->in.op = ASSIGN;
1501 			r->tn.lval = 0;
1502 			}
1503 		break;
1504 		}
1505 	}
1506 
1507 degenerate(p) register NODE *p; {
1508 	int o;
1509 	int result, i;
1510 	int lower, upper;
1511 	register NODE *l, *r;
1512 
1513 	/*
1514 	 * try to keep degenerate comparisons with constants
1515 	 * out of the table.
1516 	 */
1517 	r = p->in.right;
1518 	l = p->in.left;
1519 	if( r->in.op != ICON ||
1520 	    r->tn.name[0] != '\0' ||
1521 	    tlen(l) >= tlen(r) )
1522 		return (0);
1523 	switch( l->in.type ) {
1524 	case CHAR:
1525 		lower = -(1 << SZCHAR - 1);
1526 		upper = (1 << SZCHAR - 1) - 1;
1527 		break;
1528 	case UCHAR:
1529 		lower = 0;
1530 		upper = (1 << SZCHAR) - 1;
1531 		break;
1532 	case SHORT:
1533 		lower = -(1 << SZSHORT - 1);
1534 		upper = (1 << SZSHORT - 1) - 1;
1535 		break;
1536 	case USHORT:
1537 		lower = 0;
1538 		upper = (1 << SZSHORT) - 1;
1539 		break;
1540 	default:
1541 		cerror("unsupported type in degenerate()");
1542 		}
1543 	i = r->tn.lval;
1544 	switch( o = p->in.op ) {
1545 	case DIV:
1546 	case ASG DIV:
1547 	case MOD:
1548 	case ASG MOD:
1549 		/* DIV and MOD work like EQ */
1550 	case EQ:
1551 	case NE:
1552 		if( lower == 0 && (unsigned) i > upper )
1553 			result = o == NE;
1554 		else if( i < lower || i > upper )
1555 			result = o == NE;
1556 		else
1557 			return (0);
1558 		break;
1559 	case LT:
1560 	case GE:
1561 		if( lower == 0 && (unsigned) i > upper )
1562 			result = o == LT;
1563 		else if( i <= lower )
1564 			result = o != LT;
1565 		else if( i > upper )
1566 			result = o == LT;
1567 		else
1568 			return (0);
1569 		break;
1570 	case LE:
1571 	case GT:
1572 		if( lower == 0 && (unsigned) i >= upper )
1573 			result = o == LE;
1574 		else if( i < lower )
1575 			result = o != LE;
1576 		else if( i >= upper )
1577 			result = o == LE;
1578 		else
1579 			return (0);
1580 		break;
1581 	default:
1582 		cerror("unknown op in degenerate()");
1583 		}
1584 
1585 	if( o == MOD || o == ASG MOD ) {
1586 		r->in.op = FREE;
1587 		ncopy(p, l);
1588 		l->in.op = FREE;
1589 		}
1590 	else if( o != ASG DIV && tshape(l, SAREG|SNAME|SCON|SOREG|STARNM) ) {
1591 		/* no side effects */
1592 		tfree(l);
1593 		ncopy(p, r);
1594 		r->in.op = FREE;
1595 		p->tn.lval = result;
1596 		}
1597 	else {
1598 		if( o == ASG DIV )
1599 			p->in.op = ASSIGN;
1600 		else {
1601 			p->in.op = COMOP;
1602 			r->tn.type = INT;
1603 			}
1604 		r->tn.lval = result;
1605 		}
1606 	if( logop(o) )
1607 		p->in.type = INT;
1608 
1609 	return (1);
1610 	}
1611 
1612 /* added by jwf */
1613 struct functbl {
1614 	int fop;
1615 	TWORD ftype;
1616 	char *func;
1617 	} opfunc[] = {
1618 	DIV,		TANY,	"udiv",
1619 	MOD,		TANY,	"urem",
1620 	ASG DIV,	TANY,	"audiv",
1621 	ASG MOD,	TANY,	"aurem",
1622 	0,	0,	0 };
1623 
1624 hardops(p)  register NODE *p; {
1625 	/* change hard to do operators into function calls.  */
1626 	register NODE *q;
1627 	register struct functbl *f;
1628 	register o;
1629 	NODE *old,*temp;
1630 
1631 	o = p->in.op;
1632 	if( ! (optype(o)==BITYPE &&
1633 	       (ISUNSIGNED(p->in.left->in.type) ||
1634 		ISUNSIGNED(p->in.right->in.type))) )
1635 		return;
1636 
1637 	for( f=opfunc; f->fop; f++ ) {
1638 		if( o==f->fop ) goto convert;
1639 		}
1640 	return;
1641 
1642 	convert:
1643 	if( p->in.right->in.op == ICON && p->in.right->tn.name[0] == '\0' )
1644 		/* 'J', 'K' in zzzcode() -- assumes DIV or MOD operations */
1645 		/* save a subroutine call -- use at most 5 instructions */
1646 		return;
1647 	if( tlen(p->in.left) < SZINT/SZCHAR && tlen(p->in.right) < SZINT/SZCHAR )
1648 		/* optim2() will modify the op into an ordinary int op */
1649 		return;
1650 	if( asgop( o ) ) {
1651 		old = NIL;
1652 		switch( p->in.left->in.op ){
1653 		case FLD:
1654 			q = p->in.left->in.left;
1655 			/*
1656 			 * rewrite (lval.fld /= rval); as
1657 			 *  ((*temp).fld = udiv((*(temp = &lval)).fld,rval));
1658 			 * else the compiler will evaluate lval twice.
1659 			 */
1660 			if( q->in.op == UNARY MUL ){
1661 				/* first allocate a temp storage */
1662 				temp = talloc();
1663 				temp->in.op = OREG;
1664 				temp->tn.rval = TMPREG;
1665 				temp->tn.lval = BITOOR(freetemp(1));
1666 				temp->in.type = INCREF(p->in.type);
1667 #ifdef FLEXNAMES
1668 				temp->in.name = "";
1669 #else
1670 				temp->in.name[0] = '\0';
1671 #endif
1672 				old = q->in.left;
1673 				q->in.left = temp;
1674 			}
1675 			/* fall thru ... */
1676 
1677 		case REG:
1678 		case NAME:
1679 		case OREG:
1680 			/* change ASG OP to a simple OP */
1681 			q = talloc();
1682 			q->in.op = NOASG p->in.op;
1683 			q->in.rall = NOPREF;
1684 			q->in.type = p->in.type;
1685 			q->in.left = tcopy(p->in.left);
1686 			q->in.right = p->in.right;
1687 			p->in.op = ASSIGN;
1688 			p->in.right = q;
1689 			p = q;
1690 			f -= 2; /* Note: this depends on the table order */
1691 			/* on the right side only - replace *temp with
1692 			 *(temp = &lval), build the assignment node */
1693 			if( old ){
1694 				temp = q->in.left->in.left; /* the "*" node */
1695 				q = talloc();
1696 				q->in.op = ASSIGN;
1697 				q->in.left = temp->in.left;
1698 				q->in.right = old;
1699 				q->in.type = old->in.type;
1700 #ifdef FLEXNAMES
1701 				q->in.name = "";
1702 #else
1703 				q->in.name[0] = '\0';
1704 #endif
1705 				temp->in.left = q;
1706 			}
1707 			break;
1708 
1709 		case UNARY MUL:
1710 			/* avoid doing side effects twice */
1711 			q = p->in.left;
1712 			p->in.left = q->in.left;
1713 			q->in.op = FREE;
1714 			break;
1715 
1716 		default:
1717 			cerror( "hardops: can't compute & LHS" );
1718 			}
1719 		}
1720 
1721 	/* build comma op for args to function */
1722 	q = talloc();
1723 	q->in.op = CM;
1724 	q->in.rall = NOPREF;
1725 	q->in.type = INT;
1726 	q->in.left = p->in.left;
1727 	q->in.right = p->in.right;
1728 	p->in.op = CALL;
1729 	p->in.right = q;
1730 
1731 	/* put function name in left node of call */
1732 	p->in.left = q = talloc();
1733 	q->in.op = ICON;
1734 	q->in.rall = NOPREF;
1735 	q->in.type = INCREF( FTN + p->in.type );
1736 #ifndef FLEXNAMES
1737 	strcpy( q->in.name, f->func );
1738 #else
1739 	q->in.name = f->func;
1740 #endif
1741 	q->tn.lval = 0;
1742 	q->tn.rval = 0;
1743 
1744 	}
1745 
1746 zappost(p) NODE *p; {
1747 	/* look for ++ and -- operators and remove them */
1748 
1749 	register int o, ty;
1750 	register NODE *q;
1751 	o = p->in.op;
1752 	ty = optype( o );
1753 
1754 	switch( o ){
1755 
1756 	case INCR:
1757 	case DECR:
1758 			q = p->in.left;
1759 			p->in.right->in.op = FREE;  /* zap constant */
1760 			ncopy( p, q );
1761 			q->in.op = FREE;
1762 			return;
1763 
1764 		}
1765 
1766 	if( ty == BITYPE ) zappost( p->in.right );
1767 	if( ty != LTYPE ) zappost( p->in.left );
1768 }
1769 
1770 fixpre(p) NODE *p; {
1771 
1772 	register int o, ty;
1773 	o = p->in.op;
1774 	ty = optype( o );
1775 
1776 	switch( o ){
1777 
1778 	case ASG PLUS:
1779 			p->in.op = PLUS;
1780 			break;
1781 	case ASG MINUS:
1782 			p->in.op = MINUS;
1783 			break;
1784 		}
1785 
1786 	if( ty == BITYPE ) fixpre( p->in.right );
1787 	if( ty != LTYPE ) fixpre( p->in.left );
1788 }
1789 
1790 /*ARGSUSED*/
1791 NODE * addroreg(l) NODE *l;
1792 				/* OREG was built in clocal()
1793 				 * for an auto or formal parameter
1794 				 * now its address is being taken
1795 				 * local code must unwind it
1796 				 * back to PLUS/MINUS REG ICON
1797 				 * according to local conventions
1798 				 */
1799 {
1800 	cerror("address of OREG taken");
1801 	/*NOTREACHED*/
1802 }
1803 
1804 
1805 
1806 # ifndef ONEPASS
1807 main( argc, argv ) char *argv[]; {
1808 	return( mainp2( argc, argv ) );
1809 	}
1810 # endif
1811 
1812 strip(p) register NODE *p; {
1813 	NODE *q;
1814 
1815 	/* strip nodes off the top when no side effects occur */
1816 	for( ; ; ) {
1817 		switch( p->in.op ) {
1818 		case SCONV:			/* remove lint tidbits */
1819 			q = p->in.left;
1820 			ncopy( p, q );
1821 			q->in.op = FREE;
1822 			break;
1823 		/* could probably add a few more here */
1824 		default:
1825 			return;
1826 			}
1827 		}
1828 	}
1829 
1830 myreader(p) register NODE *p; {
1831 	strip( p );		/* strip off operations with no side effects */
1832 	canon( p );		/* expands r-vals for fields */
1833 	walkf( p, hardops );	/* convert ops to function calls */
1834 	walkf( p, optim2 );
1835 	}
1836