xref: /csrg-svn/old/pcc/ccom.vax/local2.c (revision 32941)
1 # ifndef lint
2 static char *sccsid ="@(#)local2.c	1.35 (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 && !forarg) {
508 				putstr("clr");
509 				prtype(l);
510 				putchar('\t');
511 				adrput(l);
512 				goto cleanup;
513 				}
514 			if (r->tn.lval < 0 && r->tn.lval >= -63) {
515 				putstr("mneg");
516 				prtype(l);
517 				r->tn.lval = -r->tn.lval;
518 				goto ops;
519 				}
520 			if (r->tn.lval < 0)
521 				r->in.type = r->tn.lval >= -128 ? CHAR
522 					: (r->tn.lval >= -32768 ? SHORT
523 					: INT);
524 			else if (l->in.type == FLOAT ||
525 			    l->in.type == DOUBLE)
526 				r->in.type = r->tn.lval <= 63 ? INT
527 					: (r->tn.lval <= 127 ? CHAR
528 					: (r->tn.lval <= 32767 ? SHORT
529 					: INT));
530 			else
531 				r->in.type = r->tn.lval <= 63 ? INT
532 					: (r->tn.lval <= 127 ? CHAR
533 					: (r->tn.lval <= 255 ? UCHAR
534 					: (r->tn.lval <= 32767 ? SHORT
535 					: (r->tn.lval <= 65535 ? USHORT
536 					: INT))));
537 			if (forarg && r->in.type == INT) {
538 				putstr("pushl\t");
539 				adrput(r);
540 				goto cleanup;
541 				}
542 			}
543 		else {
544 			if (forarg && tlen(r) == SZINT/SZCHAR) {
545 				putstr("pushl\t");
546 				adrput(r);
547 				goto cleanup;
548 				}
549 			putstr("moval\t");
550 			acon(r);
551 			putchar(',');
552 			adrput(l);
553 			goto cleanup;
554 			}
555 
556 	if (p->in.op == SCONV &&
557 	    !(l->in.type == FLOAT || l->in.type == DOUBLE) &&
558 	    !mixtypes(l, r)) {
559 		/*
560 		 * Because registers must always contain objects
561 		 * of the same width as INTs, we may have to
562 		 * perform two conversions to get an INT.  Can
563 		 * the conversions be collapsed into one?
564 		 */
565 		if (m = collapsible(l, r))
566 			r->in.type = m;
567 		else {
568 			/*
569 			 * Two steps are required.
570 			 */
571 			NODE *x;
572 
573 			if (forarg) {
574 				x = resc;
575 				x->in.type = l->in.type;
576 				}
577 			else {
578 				x = &resc[1];
579 				*x = *l;
580 				}
581 
582 			if (tlen(x) > tlen(r) && ISUNSIGNED(r->in.type))
583 				putstr("movz");
584 			else
585 				putstr("cvt");
586 			prtype(r);
587 			prtype(x);
588 			putchar('\t');
589 			adrput(r);
590 			putchar(',');
591 			adrput(x);
592 			putchar('\n');
593 			putchar('\t');
594 			r = x;
595 			}
596 		l->in.type = (ISUNSIGNED(l->in.type) ? UNSIGNED : INT);
597 		}
598 
599 	if ((r->in.type == UNSIGNED || r->in.type == ULONG) &&
600 	    mixtypes(l, r)) {
601 		int label1, label2;
602 		NODE *x = NULL;
603 
604 #if defined(FORT) || defined(SPRECC)
605 		if (forarg)
606 #else
607 		if (forarg || l == resc)
608 #endif
609 			{
610 			/* compute in register, convert to double when done */
611 			x = l;
612 			l = resc;
613 			l->in.type = x->in.type;
614 			}
615 
616 		label1 = getlab();
617 		label2 = getlab();
618 
619 		putstr("movl\t");
620 		adrput(r);
621 		putchar(',');
622 		adrput(l);
623 		putstr("\n\tjbsc\t$31,");
624 		adrput(l);
625 		printf(",L%d\n\tcvtl", label1);
626 		prtype(l);
627 		putchar('\t');
628 		adrput(l);
629 		putchar(',');
630 		adrput(l);
631 		printf("\n\tjbr\tL%d\nL%d:\n\tcvtl", label2, label1);
632 		prtype(l);
633 		putchar('\t');
634 		adrput(l);
635 		putchar(',');
636 		adrput(l);
637 		putstr("\n\tadd");
638 		prtype(l);
639 		putstr("2\t$0");
640 		prtype(l);
641 		putstr("2.147483648e9,");
642 		adrput(l);
643 		printf("\nL%d:", label2);
644 
645 		if (!forarg && (l->in.type == DOUBLE || l != resc))
646 			goto cleanup;
647 		if (x != NULL) {
648 			if (l == x) {
649 				r = &resc[1];
650 				*r = *l;
651 				}
652 			else {
653 				r = l;
654 				l = x;
655 				}
656 			l->in.type = DOUBLE;
657 			}
658 		putstr("\n\t");
659 		}
660 
661 	if( (l->in.type == FLOAT || l->in.type == DOUBLE) &&
662 	    (r->in.type == UCHAR || r->in.type == USHORT) ) {
663 		/* skip unnecessary unsigned to floating conversion */
664 #if defined(FORT) || defined(SPRECC)
665 		if (forarg)
666 #else
667 		if (forarg || l == resc)
668 #endif
669 			l->in.type = DOUBLE;
670 		putstr("movz");
671 		prtype(r);
672 		putstr("l\t");
673 		adrput(r);
674 		putchar(',');
675 		adrput(resc);
676 		putstr("\n\t");
677 		if (l == resc) {
678 			r = &resc[1];
679 			*r = *l;
680 			}
681 		else
682 			r = resc;
683 		r->in.type = INT;
684 		}
685 
686 #if defined(FORT) || defined(SPRECC)
687 	if (forarg && l->in.type == FLOAT)
688 #else
689 	if ((forarg || l == resc) && l->in.type == FLOAT)
690 #endif
691 		{
692 		/* perform an implicit conversion to double */
693 		l->in.type = DOUBLE;
694 		if (r->in.type != FLOAT &&
695 		    r->in.type != CHAR &&
696 		    r->in.type != SHORT) {
697 			/* trim bits from the mantissa */
698 			putstr("cvt");
699 			prtype(r);
700 			putstr("f\t");
701 			adrput(r);
702 			putchar(',');
703 			adrput(resc);
704 			putstr("\n\t");
705 			if (l == resc) {
706 				r = &resc[1];
707 				*r = *l;
708 				}
709 			else
710 				r = resc;
711 			r->in.type = FLOAT;
712 			}
713 		}
714 
715 	if (!mixtypes(l,r)) {
716 		if (tlen(l) == tlen(r)) {
717 			if (forarg && tlen(l) == SZINT/SZCHAR) {
718 				putstr("pushl\t");
719 				adrput(r);
720 				goto cleanup;
721 				}
722 			putstr("mov");
723 #ifdef FORT
724 			if (Oflag)
725 				prtype(l);
726 			else {
727 				if (l->in.type == DOUBLE)
728 					putchar('q');
729 				else if(l->in.type == FLOAT)
730 					putchar('l');
731 				else
732 					prtype(l);
733 				}
734 #else
735 			prtype(l);
736 #endif FORT
737 			goto ops;
738 			}
739 		else if (tlen(l) > tlen(r) && ISUNSIGNED(r->in.type))
740 			putstr("movz");
741 		else
742 			putstr("cvt");
743 		}
744 	else
745 		putstr("cvt");
746 	prtype(r);
747 	prtype(l);
748 ops:
749 	putchar('\t');
750 	adrput(r);
751 	putchar(',');
752 	adrput(l);
753 
754 cleanup:
755 	if (forarg)
756 		tfree(l);
757 	}
758 
759 /*
760  * collapsible(dest, src) -- if a conversion with a register destination
761  *	can be accomplished in one instruction, return the type of src
762  *	that will do the job correctly; otherwise return 0.  Note that
763  *	a register must always end up having type INT or UNSIGNED.
764  */
765 int
766 collapsible(dest, src)
767 NODE *dest, *src;
768 {
769 	int st = src->in.type;
770 	int dt = dest->in.type;
771 	int newt = 0;
772 
773 	/*
774 	 * Are there side effects of evaluating src?
775 	 * If the derived type will not be the same size as src,
776 	 * we may have to use two steps.
777 	 */
778 	if (tlen(src) > tlen(dest)) {
779 		if (tshape(src, STARREG))
780 			return (0);
781 		if (src->in.op == OREG && R2TEST(src->tn.rval))
782 			return (0);
783 		}
784 
785 	/*
786 	 * Can we get an object of dest's type by punning src?
787 	 * Praises be to great Cthulhu for little-endian machines...
788 	 */
789 	if (st == CHAR && dt == USHORT)
790 		/*
791 		 * Special case -- we must sign-extend to 16 bits.
792 		 */
793 		return (0);
794 
795 	if (tlen(src) < tlen(dest))
796 		newt = st;
797 	else
798 		newt = dt;
799 
800 	return (newt);
801 	}
802 
803 rmove( rt, rs, t ) TWORD t; {
804 	printf( "	%s	%s,%s\n",
805 #ifdef FORT
806 		!Oflag ? (t==DOUBLE ? "movq" : "movl") :
807 #endif
808 		(t==FLOAT ? "movf" : (t==DOUBLE ? "movd" : "movl")),
809 		rnames[rs], rnames[rt] );
810 	}
811 
812 struct respref
813 respref[] = {
814 	INTAREG|INTBREG,	INTAREG|INTBREG,
815 	INAREG|INBREG,	INAREG|INBREG|SOREG|STARREG|STARNM|SNAME|SCON,
816 	INTEMP,	INTEMP,
817 	FORARG,	FORARG,
818 	INTEMP,	INTAREG|INAREG|INTBREG|INBREG|SOREG|STARREG|STARNM,
819 	0,	0 };
820 
821 setregs(){ /* set up temporary registers */
822 	fregs = 6;	/* tbl- 6 free regs on VAX (0-5) */
823 	}
824 
825 /*ARGSUSED*/
826 rewfld( p ) NODE *p; {
827 	return(1);
828 	}
829 
830 /*ARGSUSED*/
831 callreg(p) NODE *p; {
832 	return( R0 );
833 	}
834 
835 base( p ) register NODE *p; {
836 	register int o = p->in.op;
837 
838 	if( o==ICON && p->tn.name[0] != '\0' ) return( 100 ); /* ie no base reg */
839 	if( o==REG ) return( p->tn.rval );
840     if( (o==PLUS || o==MINUS) && p->in.left->in.op == REG && p->in.right->in.op==ICON)
841 		return( p->in.left->tn.rval );
842     if( o==OREG && !R2TEST(p->tn.rval) && (p->in.type==INT || p->in.type==UNSIGNED || ISPTR(p->in.type)) )
843 		return( p->tn.rval + 0200*1 );
844 	if( o==INCR && p->in.left->in.op==REG ) return( p->in.left->tn.rval + 0200*2 );
845 	if( o==ASG MINUS && p->in.left->in.op==REG) return( p->in.left->tn.rval + 0200*4 );
846 	if( o==UNARY MUL && p->in.left->in.op==INCR && p->in.left->in.left->in.op==REG
847 	  && (p->in.type==INT || p->in.type==UNSIGNED || ISPTR(p->in.type)) )
848 		return( p->in.left->in.left->tn.rval + 0200*(1+2) );
849 	if( o==NAME ) return( 100 + 0200*1 );
850 	return( -1 );
851 	}
852 
853 offset( p, tyl ) register NODE *p; int tyl; {
854 
855 	if( tyl==1 &&
856 	    p->in.op==REG &&
857 	    (p->in.type==INT || p->in.type==UNSIGNED) )
858 		return( p->tn.rval );
859 	if( p->in.op==LS &&
860 	    p->in.left->in.op==REG &&
861 	    (p->in.left->in.type==INT || p->in.left->in.type==UNSIGNED) &&
862 	    p->in.right->in.op==ICON &&
863 	    p->in.right->in.name[0]=='\0' &&
864 	    (1<<p->in.right->tn.lval)==tyl)
865 		return( p->in.left->tn.rval );
866 	if( tyl==2 &&
867 	    p->in.op==PLUS &&
868 	    (p->in.left->in.type==INT || p->in.left->in.type==UNSIGNED) &&
869 	    p->in.left->in.op==REG &&
870 	    p->in.right->in.op==REG &&
871 	    p->in.left->tn.rval==p->in.right->tn.rval )
872 		return( p->in.left->tn.rval );
873 	return( -1 );
874 	}
875 
876 makeor2( p, q, b, o) register NODE *p, *q; register int b, o; {
877 	register NODE *t;
878 	NODE *f;
879 
880 	p->in.op = OREG;
881 	f = p->in.left; 	/* have to free this subtree later */
882 
883 	/* init base */
884 	switch (q->in.op) {
885 		case ICON:
886 		case REG:
887 		case OREG:
888 		case NAME:
889 			t = q;
890 			break;
891 
892 		case MINUS:
893 			q->in.right->tn.lval = -q->in.right->tn.lval;
894 		case PLUS:
895 			t = q->in.right;
896 			break;
897 
898 		case INCR:
899 		case ASG MINUS:
900 			t = q->in.left;
901 			break;
902 
903 		case UNARY MUL:
904 			t = q->in.left->in.left;
905 			break;
906 
907 		default:
908 			cerror("illegal makeor2");
909 	}
910 
911 	p->tn.lval = t->tn.lval;
912 #ifndef FLEXNAMES
913 	{
914 		register int i;
915 		for(i=0; i<NCHNAM; ++i)
916 			p->in.name[i] = t->in.name[i];
917 	}
918 #else
919 	p->in.name = t->in.name;
920 #endif
921 
922 	/* init offset */
923 	p->tn.rval = R2PACK( (b & 0177), o, (b>>7) );
924 
925 	tfree(f);
926 	return;
927 	}
928 
929 canaddr( p ) NODE *p; {
930 	register int o = p->in.op;
931 
932 	if( o==NAME || o==REG || o==ICON || o==OREG || (o==UNARY MUL && shumul(p->in.left)) ) return(1);
933 	return(0);
934 	}
935 
936 flshape( p ) NODE *p; {
937 	register int o = p->in.op;
938 
939 	return( o == REG || o == NAME || o == ICON ||
940 		(o == OREG && (!R2TEST(p->tn.rval) || tlen(p) == 1)) );
941 	}
942 
943 /* INTEMP shapes must not contain any temporary registers */
944 shtemp( p ) register NODE *p; {
945 	int r;
946 
947 	if( p->in.op == STARG ) p = p->in.left;
948 
949 	switch (p->in.op) {
950 	case REG:
951 		return( !istreg(p->tn.rval) );
952 	case OREG:
953 		r = p->tn.rval;
954 		if( R2TEST(r) ) {
955 			if( istreg(R2UPK1(r)) )
956 				return(0);
957 			r = R2UPK2(r);
958 			}
959 		return( !istreg(r) );
960 	case UNARY MUL:
961 		p = p->in.left;
962 		return( p->in.op != UNARY MUL && shtemp(p) );
963 		}
964 
965 	if( optype( p->in.op ) != LTYPE ) return(0);
966 	return(1);
967 	}
968 
969 shumul( p ) register NODE *p; {
970 	register int o;
971 	extern int xdebug;
972 
973 	if (xdebug) {
974 		int val;
975 		printf("shumul:\n");
976 		eprint(p, 0, &val, &val);
977 		}
978 
979 	o = p->in.op;
980 	if( o == NAME || (o == OREG && !R2TEST(p->tn.rval)) || o == ICON ) return( STARNM );
981 
982 	if( ( o == INCR || o == ASG MINUS ) &&
983 	    ( p->in.left->in.op == REG && p->in.right->in.op == ICON ) &&
984 	    p->in.right->in.name[0] == '\0' )
985 		{
986 		switch (p->in.type)
987 			{
988 			case CHAR|PTR:
989 			case UCHAR|PTR:
990 				o = 1;
991 				break;
992 
993 			case SHORT|PTR:
994 			case USHORT|PTR:
995 				o = 2;
996 				break;
997 
998 			case INT|PTR:
999 			case UNSIGNED|PTR:
1000 			case LONG|PTR:
1001 			case ULONG|PTR:
1002 			case FLOAT|PTR:
1003 				o = 4;
1004 				break;
1005 
1006 			case DOUBLE|PTR:
1007 				o = 8;
1008 				break;
1009 
1010 			default:
1011 				if ( ISPTR(p->in.type) &&
1012 				     ISPTR(DECREF(p->in.type)) ) {
1013 					o = 4;
1014 					break;
1015 					}
1016 				else return(0);
1017 			}
1018 		return( p->in.right->tn.lval == o ? STARREG : 0);
1019 		}
1020 
1021 	return( 0 );
1022 	}
1023 
1024 adrcon( val ) CONSZ val; {
1025 	putchar( '$' );
1026 	printf( CONFMT, val );
1027 	}
1028 
1029 conput( p ) register NODE *p; {
1030 	switch( p->in.op ){
1031 
1032 	case ICON:
1033 		acon( p );
1034 		return;
1035 
1036 	case REG:
1037 		putstr( rnames[p->tn.rval] );
1038 		return;
1039 
1040 	default:
1041 		cerror( "illegal conput" );
1042 		}
1043 	}
1044 
1045 /*ARGSUSED*/
1046 insput( p ) NODE *p; {
1047 	cerror( "insput" );
1048 	}
1049 
1050 upput( p, size ) NODE *p; int size; {
1051 	if( size == SZLONG && p->in.op == REG ) {
1052 		putstr( rnames[p->tn.rval + 1] );
1053 		return;
1054 		}
1055 	cerror( "upput" );
1056 	}
1057 
1058 adrput( p ) register NODE *p; {
1059 	register int r;
1060 	/* output an address, with offsets, from p */
1061 
1062 	if( p->in.op == FLD ){
1063 		p = p->in.left;
1064 		}
1065 	switch( p->in.op ){
1066 
1067 	case NAME:
1068 		acon( p );
1069 		return;
1070 
1071 	case ICON:
1072 		/* addressable value of the constant */
1073 		putchar( '$' );
1074 		acon( p );
1075 		return;
1076 
1077 	case REG:
1078 		putstr( rnames[p->tn.rval] );
1079 		return;
1080 
1081 	case OREG:
1082 		r = p->tn.rval;
1083 		if( R2TEST(r) ){ /* double indexing */
1084 			register int flags;
1085 
1086 			flags = R2UPK3(r);
1087 			if( flags & 1 ) putchar('*');
1088 			if( flags & 4 ) putchar('-');
1089 			if( p->tn.lval != 0 || p->in.name[0] != '\0' ) acon(p);
1090 			if( R2UPK1(r) != 100) printf( "(%s)", rnames[R2UPK1(r)] );
1091 			if( flags & 2 ) putchar('+');
1092 			printf( "[%s]", rnames[R2UPK2(r)] );
1093 			return;
1094 			}
1095 		if( r == AP ){  /* in the argument region */
1096 			if( p->in.name[0] != '\0' ) werror( "bad arg temp" );
1097 			printf( CONFMT, p->tn.lval );
1098 			putstr( "(ap)" );
1099 			return;
1100 			}
1101 		if( p->tn.lval != 0 || p->in.name[0] != '\0') acon( p );
1102 		printf( "(%s)", rnames[p->tn.rval] );
1103 		return;
1104 
1105 	case UNARY MUL:
1106 		/* STARNM or STARREG found */
1107 		if( tshape(p, STARNM) ) {
1108 			putchar( '*' );
1109 			adrput( p->in.left);
1110 			}
1111 		else {	/* STARREG - really auto inc or dec */
1112 			register NODE *q;
1113 
1114 			q = p->in.left;
1115 			if( q->in.right->tn.lval != tlen(p) )
1116 				cerror("adrput: bad auto-increment/decrement");
1117 			printf("%s(%s)%s", (q->in.op==INCR ? "" : "-"),
1118 				rnames[q->in.left->tn.rval],
1119 				(q->in.op==INCR ? "+" : "") );
1120 			p->in.op = OREG;
1121 			p->tn.rval = q->in.left->tn.rval;
1122 			p->tn.lval = (q->in.op == INCR ? -q->in.right->tn.lval : 0);
1123 #ifndef FLEXNAMES
1124 			p->in.name[0] = '\0';
1125 #else
1126 			p->in.name = "";
1127 #endif
1128 			tfree(q);
1129 		}
1130 		return;
1131 
1132 	default:
1133 		cerror( "illegal address" );
1134 		return;
1135 
1136 		}
1137 
1138 	}
1139 
1140 acon( p ) register NODE *p; { /* print out a constant */
1141 
1142 	if( p->in.name[0] == '\0' )
1143 		printf( CONFMT, p->tn.lval);
1144 	else {
1145 #ifndef FLEXNAMES
1146 		printf( "%.8s", p->in.name );
1147 #else
1148 		putstr( p->in.name );
1149 #endif
1150 		if( p->tn.lval != 0 ) {
1151 			putchar( '+' );
1152 			printf( CONFMT, p->tn.lval );
1153 			}
1154 		}
1155 	}
1156 
1157 genscall( p, cookie ) register NODE *p; {
1158 	/* structure valued call */
1159 	return( gencall( p, cookie ) );
1160 	}
1161 
1162 /* tbl */
1163 int gc_numbytes;
1164 /* tbl */
1165 
1166 /*ARGSUSED*/
1167 gencall( p, cookie ) register NODE *p; {
1168 	/* generate the call given by p */
1169 	register NODE *p1;
1170 	register int temp, temp1;
1171 	register int m;
1172 
1173 	if( p->in.right ) temp = argsize( p->in.right );
1174 	else temp = 0;
1175 
1176 	if( p->in.op == STCALL || p->in.op == UNARY STCALL ){
1177 		/* set aside room for structure return */
1178 
1179 		if( p->stn.stsize > temp ) temp1 = p->stn.stsize;
1180 		else temp1 = temp;
1181 		}
1182 
1183 	if( temp > maxargs ) maxargs = temp;
1184 	SETOFF(temp1,4);
1185 
1186 	if( p->in.right ){ /* make temp node, put offset in, and generate args */
1187 		genargs( p->in.right );
1188 		}
1189 
1190 	p1 = p->in.left;
1191 	if( p1->in.op != ICON ){
1192 		if( p1->in.op != REG ){
1193 			if( p1->in.op != OREG || R2TEST(p1->tn.rval) ){
1194 				if( p1->in.op != NAME ){
1195 					order( p1, INAREG );
1196 					}
1197 				}
1198 			}
1199 		}
1200 
1201 /* tbl
1202 	setup gc_numbytes so reference to ZC works */
1203 
1204 	gc_numbytes = temp&(0x3ff);
1205 /* tbl */
1206 
1207 	p->in.op = UNARY CALL;
1208 	m = match( p, INTAREG|INTBREG );
1209 
1210 	/* compensate for deficiency in 'ret' instruction ... wah,kre */
1211 	/* (plus in assignment to gc_numbytes above, for neatness only) */
1212 	if (temp >= 1024)
1213 		printf("	addl2	$%d,sp\n", (temp&(~0x3ff)));
1214 
1215 	return(m != MDONE);
1216 	}
1217 
1218 /* tbl */
1219 char *
1220 ccbranches[] = {
1221 	"eql",
1222 	"neq",
1223 	"leq",
1224 	"lss",
1225 	"geq",
1226 	"gtr",
1227 	"lequ",
1228 	"lssu",
1229 	"gequ",
1230 	"gtru",
1231 	};
1232 /* tbl */
1233 
1234 /*ARGSUSED*/
1235 cbgen( o, lab, mode ) { /*   printf conditional and unconditional branches */
1236 
1237 	if( o != 0 && ( o < EQ || o > UGT ) )
1238 		cerror( "bad conditional branch: %s", opst[o] );
1239 	printf( "	j%s	L%d\n", o == 0 ? "br" : ccbranches[o-EQ], lab );
1240 	}
1241 
1242 nextcook( p, cookie ) NODE *p; {
1243 	/* we have failed to match p with cookie; try another */
1244 	if( cookie == FORREW ) return( 0 );  /* hopeless! */
1245 	if( !(cookie&(INTAREG|INTBREG)) ) return( INTAREG|INTBREG );
1246 	if( !(cookie&INTEMP) && asgop(p->in.op) ) return( INTEMP|INAREG|INTAREG|INTBREG|INBREG );
1247 	return( FORREW );
1248 	}
1249 
1250 /*ARGSUSED*/
1251 lastchance( p, cook ) NODE *p; {
1252 	/* forget it! */
1253 	return(0);
1254 	}
1255 
1256 optim2( p ) register NODE *p; {
1257 	/* do local tree transformations and optimizations */
1258 
1259 	int o;
1260 	int i, mask;
1261 	register NODE *l, *r;
1262 
1263 	switch( o = p->in.op ) {
1264 
1265 	case AND:
1266 		/* commute L and R to eliminate complements and constants */
1267 		if( (l = p->in.left)->in.op == ICON && l->in.name[0] == 0 ||
1268 		    l->in.op == COMPL ) {
1269 			p->in.left = p->in.right;
1270 			p->in.right = l;
1271 			}
1272 	case ASG AND:
1273 		/* change meaning of AND to ~R&L - bic on pdp11 */
1274 		r = p->in.right;
1275 		if( r->in.op==ICON && r->in.name[0]==0 ) {
1276 			/* check for degenerate operations */
1277 			l = p->in.left;
1278 			mask = (1 << tlen(l) * SZCHAR) - 1;
1279 			if( ISUNSIGNED(r->in.type) ) {
1280 				i = (~r->tn.lval & mask);
1281 				if( i == 0 ) {
1282 					r->in.op = FREE;
1283 					ncopy(p, l);
1284 					l->in.op = FREE;
1285 					break;
1286 					}
1287 				else if( i == mask )
1288 					goto zero;
1289 				else
1290 					r->tn.lval = i;
1291 				break;
1292 				}
1293 			else if( r->tn.lval == mask &&
1294 				 tlen(l) < SZINT/SZCHAR ) {
1295 				r->in.op = SCONV;
1296 				r->in.left = l;
1297 				r->in.right = 0;
1298 				r->in.type = ENUNSIGN(l->in.type);
1299 				r->in.su = l->in.su > 1 ? l->in.su : 1;
1300 				ncopy(p, r);
1301 				p->in.left = r;
1302 				p->in.type = INT;
1303 				break;
1304 				}
1305 			/* complement constant */
1306 			r->tn.lval = ~r->tn.lval;
1307 			}
1308 		else if( r->in.op==COMPL ) { /* ~~A => A */
1309 			r->in.op = FREE;
1310 			p->in.right = r->in.left;
1311 			}
1312 		else { /* insert complement node */
1313 			p->in.right = l = talloc();
1314 			l->in.op = COMPL;
1315 			l->in.rall = NOPREF;
1316 			l->in.type = r->in.type;
1317 			l->in.left = r;
1318 			l->in.right = NULL;
1319 			}
1320 		break;
1321 
1322 	case SCONV:
1323 		l = p->in.left;
1324 #if defined(FORT) || defined(SPRECC)
1325 		if( p->in.type == FLOAT || p->in.type == DOUBLE ||
1326 		    l->in.type == FLOAT || l->in.type == DOUBLE )
1327 			return;
1328 #else
1329 		if( mixtypes(p, l) ) return;
1330 #endif
1331 		if( l->in.op == PCONV )
1332 			return;
1333 		if( (l->in.op == CALL || l->in.op == UNARY CALL) &&
1334 		    l->in.type != INT && l->in.type != UNSIGNED )
1335 			return;
1336 
1337 		/* Only trust it to get it right if the size is the same */
1338 		if( tlen(p) != tlen(l) )
1339 			return;
1340 
1341 		/* clobber conversion */
1342 		if( l->in.op != FLD )
1343 			l->in.type = p->in.type;
1344 		ncopy( p, l );
1345 		l->in.op = FREE;
1346 
1347 		break;
1348 
1349 	case ASSIGN:
1350 		/*
1351 		 * Conversions are equivalent to assignments;
1352 		 * when the two operations are combined,
1353 		 * we can sometimes zap the conversion.
1354 		 */
1355 		r = p->in.right;
1356 		l = p->in.left;
1357 		if ( r->in.op == SCONV &&
1358 		     !mixtypes(l, r) &&
1359 		     l->in.op != FLD &&
1360 		     tlen(l) == tlen(r) ) {
1361 				p->in.right = r->in.left;
1362 				r->in.op = FREE;
1363 			}
1364 		break;
1365 
1366 	case ULE:
1367 	case ULT:
1368 	case UGE:
1369 	case UGT:
1370 		p->in.op -= (UGE-GE);
1371 		if( degenerate(p) )
1372 			break;
1373 		p->in.op += (UGE-GE);
1374 		break;
1375 
1376 	case EQ:
1377 	case NE:
1378 	case LE:
1379 	case LT:
1380 	case GE:
1381 	case GT:
1382 		if( p->in.left->in.op == SCONV &&
1383 		    p->in.right->in.op == SCONV ) {
1384 			l = p->in.left;
1385 			r = p->in.right;
1386 			if( l->in.type == DOUBLE &&
1387 			    l->in.left->in.type == FLOAT &&
1388 			    r->in.left->in.type == FLOAT ) {
1389 				/* nuke the conversions */
1390 				p->in.left = l->in.left;
1391 				p->in.right = r->in.left;
1392 				l->in.op = FREE;
1393 				r->in.op = FREE;
1394 				}
1395 			/* more? */
1396 			}
1397 		(void) degenerate(p);
1398 		break;
1399 
1400 	case DIV:
1401 		if( p->in.right->in.op == ICON &&
1402 		    p->in.right->tn.name[0] == '\0' &&
1403 		    ISUNSIGNED(p->in.right->in.type) &&
1404 		    (unsigned) p->in.right->tn.lval >= 0x80000000 ) {
1405 			/* easy to do here, harder to do in zzzcode() */
1406 			p->in.op = UGE;
1407 			break;
1408 			}
1409 	case MOD:
1410 	case ASG DIV:
1411 	case ASG MOD:
1412 		/*
1413 		 * optimize DIV and MOD
1414 		 *
1415 		 * basically we spot UCHAR and USHORT and try to do them
1416 		 * as signed ints...  apparently div+mul+sub is always
1417 		 * faster than ediv for finding MOD on the VAX, when
1418 		 * full unsigned MOD isn't needed.
1419 		 *
1420 		 * a curious fact: for MOD, cmp+sub and cmp+sub+cmp+sub
1421 		 * are faster for unsigned dividend and a constant divisor
1422 		 * in the right range (.5 to 1 of dividend's range for the
1423 		 * first, .333+ to .5 for the second).  full unsigned is
1424 		 * already done cmp+sub in the appropriate case; the
1425 		 * other cases are less common and require more ambition.
1426 		 */
1427 		if( degenerate(p) )
1428 			break;
1429 		l = p->in.left;
1430 		r = p->in.right;
1431 		if( !ISUNSIGNED(r->in.type) ||
1432 		    tlen(l) >= SZINT/SZCHAR ||
1433 		    !(tlen(r) < SZINT/SZCHAR ||
1434 		      (r->in.op == ICON && r->tn.name[0] == '\0')) )
1435 			break;
1436 		if( r->in.op == ICON )
1437 			r->tn.type = INT;
1438 		else {
1439 			NODE *t = talloc();
1440 			t->in.left = r;
1441 			r = t;
1442 			r->in.op = SCONV;
1443 			r->in.type = INT;
1444 			r->in.right = 0;
1445 			p->in.right = r;
1446 			}
1447 		if( o == DIV || o == MOD ) {
1448 			NODE *t = talloc();
1449 			t->in.left = l;
1450 			l = t;
1451 			l->in.op = SCONV;
1452 			l->in.type = INT;
1453 			l->in.right = 0;
1454 			p->in.left = l;
1455 			}
1456 		/* handle asgops in table */
1457 		break;
1458 
1459 	case RS:
1460 	case ASG RS:
1461 	case LS:
1462 	case ASG LS:
1463 		/* pick up degenerate shifts */
1464 		l = p->in.left;
1465 		r = p->in.right;
1466 		if( !(r->in.op == ICON && r->tn.name[0] == '\0') )
1467 			break;
1468 		i = r->tn.lval;
1469 		if( i < 0 )
1470 			/* front end 'fixes' this? */
1471 			if( o == LS || o == ASG LS )
1472 				o += (RS-LS);
1473 			else
1474 				o += (LS-RS);
1475 		if( (o == RS || o == ASG RS) &&
1476 		    !ISUNSIGNED(l->in.type) )
1477 			/* can't optimize signed right shifts */
1478 			break;
1479 		if( o == LS ) {
1480 			if( i < SZINT )
1481 				break;
1482 			}
1483 		else {
1484 			if( i < tlen(l) * SZCHAR )
1485 				break;
1486 			}
1487 	zero:
1488 		if( !asgop( o ) )
1489 			if( tshape(l, SAREG|SNAME|SCON|SOREG|STARNM) ) {
1490 				/* no side effects */
1491 				tfree(l);
1492 				ncopy(p, r);
1493 				r->in.op = FREE;
1494 				p->tn.lval = 0;
1495 				}
1496 			else {
1497 				p->in.op = COMOP;
1498 				r->tn.lval = 0;
1499 				}
1500 		else {
1501 			p->in.op = ASSIGN;
1502 			r->tn.lval = 0;
1503 			}
1504 		break;
1505 		}
1506 	}
1507 
1508 degenerate(p) register NODE *p; {
1509 	int o;
1510 	int result, i;
1511 	int lower, upper;
1512 	register NODE *l, *r;
1513 
1514 	/*
1515 	 * try to keep degenerate comparisons with constants
1516 	 * out of the table.
1517 	 */
1518 	r = p->in.right;
1519 	l = p->in.left;
1520 	if( r->in.op != ICON ||
1521 	    r->tn.name[0] != '\0' ||
1522 	    tlen(l) >= tlen(r) )
1523 		return (0);
1524 	switch( l->in.type ) {
1525 	case CHAR:
1526 		lower = -(1 << SZCHAR - 1);
1527 		upper = (1 << SZCHAR - 1) - 1;
1528 		break;
1529 	case UCHAR:
1530 		lower = 0;
1531 		upper = (1 << SZCHAR) - 1;
1532 		break;
1533 	case SHORT:
1534 		lower = -(1 << SZSHORT - 1);
1535 		upper = (1 << SZSHORT - 1) - 1;
1536 		break;
1537 	case USHORT:
1538 		lower = 0;
1539 		upper = (1 << SZSHORT) - 1;
1540 		break;
1541 	default:
1542 		cerror("unsupported type in degenerate()");
1543 		}
1544 	i = r->tn.lval;
1545 	switch( o = p->in.op ) {
1546 	case DIV:
1547 	case ASG DIV:
1548 	case MOD:
1549 	case ASG MOD:
1550 		/* DIV and MOD work like EQ */
1551 	case EQ:
1552 	case NE:
1553 		if( lower == 0 && (unsigned) i > upper )
1554 			result = o == NE;
1555 		else if( i < lower || i > upper )
1556 			result = o == NE;
1557 		else
1558 			return (0);
1559 		break;
1560 	case LT:
1561 	case GE:
1562 		if( lower == 0 && (unsigned) i > upper )
1563 			result = o == LT;
1564 		else if( i <= lower )
1565 			result = o != LT;
1566 		else if( i > upper )
1567 			result = o == LT;
1568 		else
1569 			return (0);
1570 		break;
1571 	case LE:
1572 	case GT:
1573 		if( lower == 0 && (unsigned) i >= upper )
1574 			result = o == LE;
1575 		else if( i < lower )
1576 			result = o != LE;
1577 		else if( i >= upper )
1578 			result = o == LE;
1579 		else
1580 			return (0);
1581 		break;
1582 	default:
1583 		cerror("unknown op in degenerate()");
1584 		}
1585 
1586 	if( o == MOD || o == ASG MOD ) {
1587 		r->in.op = FREE;
1588 		ncopy(p, l);
1589 		l->in.op = FREE;
1590 		}
1591 	else if( o != ASG DIV && tshape(l, SAREG|SNAME|SCON|SOREG|STARNM) ) {
1592 		/* no side effects */
1593 		tfree(l);
1594 		ncopy(p, r);
1595 		r->in.op = FREE;
1596 		p->tn.lval = result;
1597 		}
1598 	else {
1599 		if( o == ASG DIV )
1600 			p->in.op = ASSIGN;
1601 		else {
1602 			p->in.op = COMOP;
1603 			r->tn.type = INT;
1604 			}
1605 		r->tn.lval = result;
1606 		}
1607 	if( logop(o) )
1608 		p->in.type = INT;
1609 
1610 	return (1);
1611 	}
1612 
1613 /* added by jwf */
1614 struct functbl {
1615 	int fop;
1616 	TWORD ftype;
1617 	char *func;
1618 	} opfunc[] = {
1619 	DIV,		TANY,	"udiv",
1620 	MOD,		TANY,	"urem",
1621 	ASG DIV,	TANY,	"audiv",
1622 	ASG MOD,	TANY,	"aurem",
1623 	0,	0,	0 };
1624 
1625 hardops(p)  register NODE *p; {
1626 	/* change hard to do operators into function calls.  */
1627 	register NODE *q;
1628 	register struct functbl *f;
1629 	register o;
1630 	NODE *old,*temp;
1631 
1632 	o = p->in.op;
1633 	if( ! (optype(o)==BITYPE &&
1634 	       (ISUNSIGNED(p->in.left->in.type) ||
1635 		ISUNSIGNED(p->in.right->in.type))) )
1636 		return;
1637 
1638 	for( f=opfunc; f->fop; f++ ) {
1639 		if( o==f->fop ) goto convert;
1640 		}
1641 	return;
1642 
1643 	convert:
1644 	if( p->in.right->in.op == ICON && p->in.right->tn.name[0] == '\0' )
1645 		/* 'J', 'K' in zzzcode() -- assumes DIV or MOD operations */
1646 		/* save a subroutine call -- use at most 5 instructions */
1647 		return;
1648 	if( tlen(p->in.left) < SZINT/SZCHAR && tlen(p->in.right) < SZINT/SZCHAR )
1649 		/* optim2() will modify the op into an ordinary int op */
1650 		return;
1651 	if( asgop( o ) ) {
1652 		old = NIL;
1653 		switch( p->in.left->in.op ){
1654 		case FLD:
1655 			q = p->in.left->in.left;
1656 			/*
1657 			 * rewrite (lval.fld /= rval); as
1658 			 *  ((*temp).fld = udiv((*(temp = &lval)).fld,rval));
1659 			 * else the compiler will evaluate lval twice.
1660 			 */
1661 			if( q->in.op == UNARY MUL ){
1662 				/* first allocate a temp storage */
1663 				temp = talloc();
1664 				temp->in.op = OREG;
1665 				temp->tn.rval = TMPREG;
1666 				temp->tn.lval = BITOOR(freetemp(1));
1667 				temp->in.type = INCREF(p->in.type);
1668 #ifdef FLEXNAMES
1669 				temp->in.name = "";
1670 #else
1671 				temp->in.name[0] = '\0';
1672 #endif
1673 				old = q->in.left;
1674 				q->in.left = temp;
1675 			}
1676 			/* fall thru ... */
1677 
1678 		case REG:
1679 		case NAME:
1680 		case OREG:
1681 			/* change ASG OP to a simple OP */
1682 			q = talloc();
1683 			q->in.op = NOASG p->in.op;
1684 			q->in.rall = NOPREF;
1685 			q->in.type = p->in.type;
1686 			q->in.left = tcopy(p->in.left);
1687 			q->in.right = p->in.right;
1688 			p->in.op = ASSIGN;
1689 			p->in.right = q;
1690 			p = q;
1691 			f -= 2; /* Note: this depends on the table order */
1692 			/* on the right side only - replace *temp with
1693 			 *(temp = &lval), build the assignment node */
1694 			if( old ){
1695 				temp = q->in.left->in.left; /* the "*" node */
1696 				q = talloc();
1697 				q->in.op = ASSIGN;
1698 				q->in.left = temp->in.left;
1699 				q->in.right = old;
1700 				q->in.type = old->in.type;
1701 #ifdef FLEXNAMES
1702 				q->in.name = "";
1703 #else
1704 				q->in.name[0] = '\0';
1705 #endif
1706 				temp->in.left = q;
1707 			}
1708 			break;
1709 
1710 		case UNARY MUL:
1711 			/* avoid doing side effects twice */
1712 			q = p->in.left;
1713 			p->in.left = q->in.left;
1714 			q->in.op = FREE;
1715 			break;
1716 
1717 		default:
1718 			cerror( "hardops: can't compute & LHS" );
1719 			}
1720 		}
1721 
1722 	/* build comma op for args to function */
1723 	q = talloc();
1724 	q->in.op = CM;
1725 	q->in.rall = NOPREF;
1726 	q->in.type = INT;
1727 	q->in.left = p->in.left;
1728 	q->in.right = p->in.right;
1729 	p->in.op = CALL;
1730 	p->in.right = q;
1731 
1732 	/* put function name in left node of call */
1733 	p->in.left = q = talloc();
1734 	q->in.op = ICON;
1735 	q->in.rall = NOPREF;
1736 	q->in.type = INCREF( FTN + p->in.type );
1737 #ifndef FLEXNAMES
1738 	strcpy( q->in.name, f->func );
1739 #else
1740 	q->in.name = f->func;
1741 #endif
1742 	q->tn.lval = 0;
1743 	q->tn.rval = 0;
1744 
1745 	}
1746 
1747 zappost(p) NODE *p; {
1748 	/* look for ++ and -- operators and remove them */
1749 
1750 	register int o, ty;
1751 	register NODE *q;
1752 	o = p->in.op;
1753 	ty = optype( o );
1754 
1755 	switch( o ){
1756 
1757 	case INCR:
1758 	case DECR:
1759 			q = p->in.left;
1760 			p->in.right->in.op = FREE;  /* zap constant */
1761 			ncopy( p, q );
1762 			q->in.op = FREE;
1763 			return;
1764 
1765 		}
1766 
1767 	if( ty == BITYPE ) zappost( p->in.right );
1768 	if( ty != LTYPE ) zappost( p->in.left );
1769 }
1770 
1771 fixpre(p) NODE *p; {
1772 
1773 	register int o, ty;
1774 	o = p->in.op;
1775 	ty = optype( o );
1776 
1777 	switch( o ){
1778 
1779 	case ASG PLUS:
1780 			p->in.op = PLUS;
1781 			break;
1782 	case ASG MINUS:
1783 			p->in.op = MINUS;
1784 			break;
1785 		}
1786 
1787 	if( ty == BITYPE ) fixpre( p->in.right );
1788 	if( ty != LTYPE ) fixpre( p->in.left );
1789 }
1790 
1791 /*ARGSUSED*/
1792 NODE * addroreg(l) NODE *l;
1793 				/* OREG was built in clocal()
1794 				 * for an auto or formal parameter
1795 				 * now its address is being taken
1796 				 * local code must unwind it
1797 				 * back to PLUS/MINUS REG ICON
1798 				 * according to local conventions
1799 				 */
1800 {
1801 	cerror("address of OREG taken");
1802 	/*NOTREACHED*/
1803 }
1804 
1805 
1806 
1807 # ifndef ONEPASS
1808 main( argc, argv ) char *argv[]; {
1809 	return( mainp2( argc, argv ) );
1810 	}
1811 # endif
1812 
1813 strip(p) register NODE *p; {
1814 	NODE *q;
1815 
1816 	/* strip nodes off the top when no side effects occur */
1817 	for( ; ; ) {
1818 		switch( p->in.op ) {
1819 		case SCONV:			/* remove lint tidbits */
1820 			q = p->in.left;
1821 			ncopy( p, q );
1822 			q->in.op = FREE;
1823 			break;
1824 		/* could probably add a few more here */
1825 		default:
1826 			return;
1827 			}
1828 		}
1829 	}
1830 
1831 myreader(p) register NODE *p; {
1832 	strip( p );		/* strip off operations with no side effects */
1833 	canon( p );		/* expands r-vals for fields */
1834 	walkf( p, hardops );	/* convert ops to function calls */
1835 	walkf( p, optim2 );
1836 	}
1837