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to terminate but many of the values in the range of the loop are bogus
[unix-history] / usr / src / old / pcc / c2.vax / c21.c
CommitLineData
41feb04a 1#ifndef lint
f69fb1e7 2static char sccsid[] = "@(#)c21.c 4.19 %G%";
41feb04a 3#endif
35307d30 4/* char C21[] = {"@(#)c21.c 1.83 80/10/16 21:18:22 JFR"}; /* sccs ident */
f00d91fc
BJ		 5
6/*
7 * C object code improver-- second part
8 */
9
10#include "c2.h"
11#include <stdio.h>
12#include <ctype.h>
13
14#define NUSE 6
15int ioflag;
16int biti[NUSE] = {1,2,4,8,16,32};
0594fe30 17int bitsize[] = { /* index by type codes */
a24e0abe
RH		 18 0, /* 0 not allocated */
19 8, /* 1 BYTE */
20 16, /* 2 WORD */
21 32, /* 3 LONG */
22 32, /* 4 FFLOAT /
23 64, /* 5 DFLOAT */
24 64, /* 6 QUAD */
25 0, /* 7 OP2 */
26 0, /* 8 OP3 */
27 0, /* 9 OPB */
28 0, /* 10 OPX */
29 64, /* 11 GFLOAT */
30 128, /* 12 HFLOAT */
31 128 /* 13 OCTA */
0594fe30 32};
f00d91fc
BJ		 33int pos,siz; long f; /* for bit field communication */
34struct node *uses[NUSE]; /* for backwards flow analysis */
35char *lastrand; /* last operand of instruction */
36struct node *bflow();
37struct node *bicopt();
38char *findcon();
41feb04a 39char *strcpy();
f00d91fc
BJ		 40
41redun3(p,split) register struct node *p; int split; {
42/* check for 3 addr instr which should be 2 addr */
43 if (OP3==((p->subop>>4)&0xF)) {
44 if (split) splitrand(p);
45 if (equstr(regs[RT1],regs[RT3])
46 && (p->op==ADD || p->op==MUL || p->op==BIS || p->op==XOR)) {
47 register char *t=regs[RT1]; regs[RT1]=regs[RT2]; regs[RT2]=t;
48 }
49 if (equstr(regs[RT2],regs[RT3])) {
50 p->subop=(p->subop&0xF)|(OP2<<4); p->pop=0;
51 lastrand=regs[RT2]; *regs[RT3]=0; return(1);
52 }
53 } return(0);
54}
55
56bmove() {
57 register struct node *p, *lastp; register char *cp1,*cp2; register int r;
58 refcount();
59 for (p=lastp= &first; 0!=(p=p->forw); lastp=p);
60 clearreg(); clearuse();
61 for (p=lastp; p!= &first; p=p->back) {
62 if (debug) {
63 printf("Uses:\n");
64 for (r=NUSE;--r>=0;) if (uses[r])
65 printf("%d: %s\n",r,uses[r]->code? uses[r]->code:"");
66 printf("-\n");
67 }
68 r=(p->subop>>4)&0xF;
69 if (OP2==r && (cp1=p->code, *cp1++)=='$' && *cp1++=='0' && *cp1++==',' &&
70 !source(cp1)) {/* a no-op unless MUL or DIV */
71 if (p->op==MUL) {p->op=MOV; p->subop&=0xF; p->pop=0;}
72 else if (p->op==DIV) fprintf(stderr,"c2: zero divide\n");
73 else {delnode(p); redunm++; continue;}
74 }
75 if (OP3==r && 0!=redun3(p,1)) {newcode(p); redunm++;}
76 switch (p->op) {
77 case LABEL: case DLABEL:
78 for (r=NUSE; --r>=0;)
79 if (uses[r]) p->ref=(struct node *) (((int)p->ref)|biti[r]);
80 break;
81 case CALLS:
82 clearuse(); goto std;
83 case 0:
11850887
RC		 84 /*
85 * Be conservative -- if we don't know what it is, then we
86 * assume that it can set anything.
87 */
88 for ( r = 0; r < NUSE; ++r )
89 uses[r] = p;
90 break;
f00d91fc
BJ		 91 case SUB:
92 if ((p->subop&0xF)!=LONG) goto std; cp1=p->code;
93 if (*cp1++!='$') goto std; splitrand(p);
94 if (equstr(regs[RT2],"fp") && !indexa(regs[RT1])) {/* address comp. */
3b60efae 95 char buf[C2_ASIZE]; cp2=buf; *cp2++='-';
f00d91fc
BJ		 96 cp1=regs[RT1]+1; while (*cp2++= *cp1++); --cp2;
97 cp1="(fp),"; while (*cp2++= *cp1++); --cp2;
98 cp1=regs[RT3]; while (*cp2++= *cp1++);
99 p->code=copy(buf); p->combop=T(MOVA,LONG); p->pop=0;
100 } else if (*cp1++=='-' && 0<=(r=getnum(cp1))) {
101 p->op=ADD; p->pop=0; *--cp1='$'; p->code=cp1;
102 } goto std;
103 case ADD:
104 if ((p->subop&0xF)!=LONG) goto std; cp1=p->code;
105 if (*cp1++!='$') goto std; splitrand(p);
106 if (isstatic(cp1) && (r=isreg(regs[RT2]))>=0 && r<NUSE && uses[r]==p->forw)
107 {
108 /* address comp:
109 ** addl2 $_foo,r0 \ movab _foo[r0],bar
110 ** movl r0,bar /
111 */
112 register struct node *pnext = p->forw;
3b60efae 113 char buf[C2_ASIZE];
f00d91fc
BJ		 114
115 if (pnext->op == MOV && pnext->subop == LONG)
116 {
117 cp1 = &regs[RT1][1]; cp2 = &buf[0];
118 while (*cp2++ = *cp1++) ; cp2--;
119 splitrand(pnext);
120 if (r == isreg(regs[RT1]))
121 {
122 delnode(p); p = pnext;
123 p->op = MOVA; p->subop = BYTE;
124 p->pop = 0;
125 cp1 = regs[RT1]; *cp2++ = '[';
126 while (*cp2++ = *cp1++) ; cp2--;
127 *cp2++ = ']'; *cp2++ = ',';
128 cp1 = regs[RT2];
129 while (*cp2++ = *cp1++) ;
130 p->code = copy(buf);
131 }
132 }
133 }
134 else
135 if (equstr(regs[RT2],"fp") && !indexa(regs[RT1])) {/* address comp. */
136 cp2=cp1-1; cp1=regs[RT1]+1; while (*cp2++= *cp1++); --cp2;
137 cp1="(fp)"; while (*cp2++= *cp1++); *--cp2=',';
138 p->combop=T(MOVA,LONG); p->pop=0;
139 } else if (*cp1++=='-' && 0<=(r=getnum(cp1))) {
140 p->op=SUB; p->pop=0; *--cp1='$'; p->code=cp1;
141 }
142 /* fall thru ... */
143 case CASE:
144 default: std:
145 p=bflow(p); break;
146 case MUL:
147 {
148 /*
149 ** Change multiplication by constant powers of 2 to
150 ** shifts.
151 */
152 splitrand(p);
153 if (regs[RT1][0] != '$' || regs[RT1][1] == '-') goto std;
154 if ((r = ispow2(getnum(&regs[RT1][1]))) < 0) goto std;
155 switch (r)
156 {
157 case 0: /* mull3 $1,x,y */
158 if (p->subop == U(LONG,OP3))
159 {
160 if (equstr(regs[RT2], regs[RT3]))
161 {
162 delnode(p); p = p->forw;
163 }
164 else
165 {
166 p->op = MOV; p->subop = LONG;
167 p->pop = 0; newcode(p); nchange++;
168 }
169 }
170 else
171 if (p->subop == U(LONG,OP2))
172 {
173 delnode(p); p = p->forw;
174 }
175 goto std;
176
177 case 1: /* mull2 $2,x */
178 if (p->subop == U(LONG, OP2) && !source(regs[RT2]))
179 {
180 strcpy(regs[RT1], regs[RT2]);
181 p->op = ADD; p->pop = 0; newcode(p); nchange++;
182 }
183 goto std;
184 }
185 if(p->subop==U(LONG,OP3)||(p->subop==U(LONG,OP2)&&!source(regs[RT2])))
186 {
187 if (p->subop == U(LONG,OP2))
188 strcpy(regs[RT3], regs[RT2]);
189 sprintf(regs[RT1], "$%d", r);
190 p->op = ASH; p->subop = LONG;
191 p->pop = 0; newcode(p); nchange++;
192 }
193 goto std;
194 }
195 case ASH:
196 {
197 /* address comp:
198 ** ashl $1,bar,r0 \ movl bar,r0
199 ** movab _foo[r0] / movaw _foo[r0]
200 **
201 ** ashl $2,r0,r0 \ moval _foo[r0]
202 ** movab _foo[r0] /
203 */
204 register struct node *pf;
205 register int shfrom, shto;
206 long shcnt;
207 char *regfrom;
208
209 splitrand(p);
210 if (regs[RT1][0] != '$') goto std;
211 if ((shcnt = getnum(&regs[RT1][1])) < 1 || shcnt > 3) goto std;
212 if ((shfrom = isreg(regs[RT2])) >= 0)
41feb04a 213 regfrom = copy(regs[RT2]);
f00d91fc
BJ		 214 if ((shto = isreg(regs[RT3])) >= 0 && shto<NUSE)
215 {
216 int regnum;
217
218 if (uses[shto] != (pf = p->forw)) goto ashadd;
219 if (pf->op != MOVA && pf->op != PUSHA) goto ashadd;
220 if (pf->subop != BYTE) goto ashadd;
221 splitrand(pf);
222 if (!indexa(regs[RT1])) goto std;
223 cp2 = regs[RT1];
224 if(!isstatic(cp2)) goto std;
225 while (*cp2++ != '[') ;
226 if (*cp2++ != 'r' || !isdigit(*cp2)) goto std;
227 regnum = *cp2++ - '0';
228 if (isdigit(*cp2))
229 {
230 if (cp2[1] != ']') goto std;
231 regnum *= 10; regnum += *cp2 - '0';
232 }
233 if (regnum != shto) goto std;
234 if (shfrom >= 0) /* ashl $N,r*,r0 */
235 {
236 delnode(p);
237 if (shfrom != shto)
238 {
239 uses[shto] = NULL; splitrand(pf);
240 cp2=regs[RT1]; while (*cp2++!='[');
241 cp1=regfrom; while (*cp2++= *cp1++);
41feb04a
RC		 242 *--cp2 = ']';
243 *++cp2 = '\0';
f00d91fc
BJ		 244 newcode(pf);
245 }
246 }
247 else
248 {
249 p->op = MOV; splitrand(p);
250 strcpy(regs[RT1], regs[RT2]);
251 strcpy(regs[RT2], regs[RT3]);
252 regs[RT3][0] = '\0';
253 p->pop = 0; newcode(p);
254 }
255 switch (shcnt)
256 {
257 case 1: pf->subop = WORD; break;
258 case 2: pf->subop = LONG; break;
259 case 3: pf->subop = QUAD; break;
260 }
261 redunm++; nsaddr++; nchange++;
725aa107 262 goto std;
f00d91fc 263 }
f00d91fc
BJ		 264ashadd:
265 /* at this point, RT2 and RT3 are guaranteed to be simple regs*/
266 if (shcnt == 1 && equstr(regs[RT2], regs[RT3]))
267 {
268 /*
269 ** quickie:
270 ** ashl $1,A,A > addl2 A,A
271 */
272 p->op = ADD; p->subop = U(LONG,OP2); p->pop = 0;
273 strcpy(regs[RT1], regs[RT2]); regs[RT3][0] = '\0';
274 newcode(p); nchange++;
275 }
276 goto std;
277 }
278
279 case EXTV:
280 case EXTZV:
281 {
282 /* bit tests:
283 ** extv A,$1,B,rC \
284 ** tstl rC > jbc A,B,D
285 ** jeql D /
286 **
287 ** also byte- and word-size fields:
288 ** extv $n*8,$8,A,B > cvtbl n+A,B
49c27f9c 289 ** extv $n*16,$16,A,B > cvtwl 2n+A,B
f00d91fc 290 ** extzv $n*8,$8,A,B > movzbl n+A,B
49c27f9c 291 ** extzv $n*16,$16,A,B > movzwl 2n+A,B
f00d91fc
BJ		 292 */
293 register struct node *pf; /* forward node */
294 register struct node *pn; /* next node (after pf) */
295 int flen; /* field length */
296
297 splitrand(p);
298 if (regs[RT2][0] != '$') goto std;
299 if ((flen = getnum(&regs[RT2][1])) < 0) goto std;
300 if (flen == 1)
301 {
302 register int extreg; /* reg extracted to */
303
304 extreg = isreg(regs[RT4]);
305 if (extreg < 0 || extreg >= NUSE) goto std;
306 if ((pf = p->forw)->op != TST) goto std;
307 if (uses[extreg] && uses[extreg] != pf) goto std;
308 splitrand(pf);
309 if (extreg != isreg(regs[RT1])) goto std;
310 if ((pn = pf->forw)->op != CBR) goto std;
311 if (pn->subop != JEQ && pn->subop != JNE) goto std;
312 delnode(p); delnode(pf);
313 pn->subop = (pn->subop == JEQ) ? JBC : JBS;
314 for(cp2=p->code; *cp2++!=',';);
315 for(cp1=cp2; *cp1++!=',';);
316 while (*cp1!=',') *cp2++= *cp1++; *cp2='\0';
317 pn->code = p->code; pn->pop = NULL;
318 uses[extreg] = NULL;
319 }
320 else
321 if (flen == 8 || flen == 16)
322 {
323 register int boff; /* bit offset */
324 register int coff; /* chunk (byte or word) offset*/
325
326 if (regs[RT1][0] != '$') goto std;
327 if ((boff = getnum(&regs[RT1][1])) < 0) goto std;
328 coff = boff / flen;
329 if (coff && (isreg(regs[RT3]) >= 0)) goto std;
330 if (boff < 0 || (boff % flen) != 0) goto std;
331 p->op = (p->op == EXTV) ? CVT : MOVZ;
332 p->subop = U((flen == 8 ? BYTE : WORD), LONG);
333 if (coff == 0)
334 strcpy(regs[RT1], regs[RT3]);
335 else
49c27f9c
RC		 336 sprintf(regs[RT1], "%d%s%s",
337 (flen == 8 ? coff : 2*coff),
338 (regs[RT3][0] == '(' ? "" : "+"),
f00d91fc
BJ		 339 regs[RT3]);
340 strcpy(regs[RT2], regs[RT4]);
341 regs[RT3][0] = '\0'; regs[RT4][0] = '\0';
342 p->pop = 0; newcode(p);
343 }
344 nchange++;
345 goto std;
346 }
347
348 case CMP:
349 {
350 /* comparison to -63 to -1:
351 ** cmpl r0,$-1 > incl r0
352 ** jeql ...
353 **
354 ** cmpl r0,$-63 > addl2 $63,r0
355 ** jeql ...
356 */
357 register int num;
358 register int reg;
359 register struct node *regp = p->back;
360
361 if (p->forw->op != CBR) goto std;
362 if (p->forw->subop != JEQ && p->forw->subop != JNE) goto std;
363 splitrand(p);
364 if (strncmp(regs[RT2], "$-", 2) != 0) goto std;
365 reg = r = isreg(regs[RT1]);
366 if (r < 0) goto std;
367 if (r < NUSE && uses[r] != 0) goto std;
368 if (r >= NUSE && regp->op == MOV && p->subop == regp->subop)
369 {
370 if (*regp->code != 'r') goto std;
371 reg = regp->code[1] - '0';
372 if (isdigit(regp->code[2]) || reg >= NUSE || uses[reg])
373 goto std;
374 }
375 if (r >= NUSE) goto std;
376 if (reg != r)
377 sprintf(regs[RT1], "r%d", reg);
378 if ((num = getnum(&regs[RT2][2])) <= 0 || num > 63) goto std;
379 if (num == 1)
380 {
381 p->op = INC; regs[RT2][0] = '\0';
382 }
383 else
384 {
385 register char *t;
386
387 t=regs[RT1];regs[RT1]=regs[RT2];regs[RT2]=t;
388 p->op = ADD; p->subop = U(p->subop, OP2);
389 for (t = &regs[RT1][2]; t[-1] = *t; t++) ;
390 }
391 p->pop = 0; newcode(p);
392 nchange++;
393 goto std;
394 }
395
396 case JSB:
397 if (equstr(p->code,"mcount")) {uses[0]=p; regs[0][0]= -1;}
398 goto std;
399 case JBR: case JMP:
400 clearuse();
401 if (p->subop==RET || p->subop==RSB) {uses[0]=p; regs[0][0]= -1; break;}
402 if (p->ref==0) goto std; /* jmp (r0) */
403 /* fall through */
404 case CBR:
405 if (p->ref->ref!=0) for (r=NUSE;--r>=0;)
406 if (biti[r] & (int)p->ref->ref) {uses[r]=p; regs[r][0]= -1;}
407 case EROU: case JSW:
408 case TEXT: case DATA: case BSS: case ALIGN: case WGEN: case END: ;
409 }
410 }
411 for (p= &first; p!=0; p=p->forw)
412 if (p->op==LABEL || p->op==DLABEL) p->ref=0; /* erase our tracks */
413}
414
415rmove()
416{
41feb04a 417 register struct node *p;
f00d91fc
BJ		 418 register int r;
419 int r1;
420
421 clearreg();
422 for (p=first.forw; p!=0; p = p->forw) {
f00d91fc 423 if (debug) {
6b028d93
RC		 424 if (*conloc) {
425 r1=conval[0];
426 printf("Con %s = %d%d %s\n", conloc, r1&0xF, r1>>4, conval+1);
427 }
f00d91fc
BJ		 428 printf("Regs:\n");
429 for (r=0; r<NREG; r++)
430 if (regs[r][0]) {
431 r1=regs[r][0];
432 printf("%d: %d%d %s\n", r, r1&0xF, r1>>4, regs[r]+1);
433 }
434 printf("-\n");
435 }
436 switch (p->op) {
437
438 case CVT:
439 splitrand(p); goto mov;
440
441 case MOV:
442 splitrand(p);
443 if ((r = findrand(regs[RT1],p->subop)) >= 0) {
444 if (r == isreg(regs[RT2]) && p->forw->op!=CBR) {
445 delnode(p); redunm++; break;
446 }
447 }
448mov:
449 repladdr(p);
450 r = isreg(regs[RT1]);
451 r1 = isreg(regs[RT2]);
452 dest(regs[RT2],p->subop);
d1580951
BJ		 453 if (r>=0) {
454 if (r1>=0) savereg(r1, regs[r]+1, p->subop);
455 else if (p->op!=CVT) savereg(r, regs[RT2], p->subop);
456 } else if (r1>=0) savereg(r1, regs[RT1], p->subop);
457 else if (p->op!=CVT) setcon(regs[RT1], regs[RT2], p->subop);
f00d91fc
BJ		 458 break;
459
460/* .rx,.wx */
461 case MFPR:
462 case COM:
463 case NEG:
464/* .rx,.wx or .rx,.rx,.wx */
465 case ADD:
466 case SUB:
467 case BIC:
468 case BIS:
469 case XOR:
470 case MUL:
471 case DIV:
472 case ASH:
473 case MOVZ:
474/* .rx,.rx,.rx,.wx */
475 case EXTV:
476 case EXTZV:
477 case INSV:
478 splitrand(p);
479 repladdr(p);
480 dest(lastrand,p->subop);
481 if (p->op==INSV) ccloc[0]=0;
482 break;
483
484/* .mx or .wx */
485 case CLR:
486 case INC:
487 case DEC:
488 splitrand(p);
489 dest(lastrand,p->subop);
490 if (p->op==CLR)
491 if ((r = isreg(regs[RT1])) >= 0)
492 savereg(r, "$0", p->subop);
493 else
494 setcon("$0", regs[RT1], p->subop);
495 break;
496
497/* .rx */
498 case TST:
499 case PUSH:
500 splitrand(p);
501 lastrand=regs[RT1+1]; /* fool repladdr into doing 1 operand */
502 repladdr(p);
503 if (p->op==TST && equstr(lastrand=regs[RT1], ccloc+1)
504 && ((0xf&(ccloc[0]>>4))==p->subop || equtype(ccloc[0],p->subop))
505 &&!source(lastrand)) {
506 delnode(p); p = p->back; nrtst++; nchange++;
507 }
508 setcc(lastrand,p->subop);
509 break;
510
511/* .rx,.rx,.rx */
512 case PROBER:
513 case PROBEW:
514 case CASE:
515 case MOVC3:
516/* .rx,.rx */
517 case MTPR:
518 case CALLS:
519 case CMP:
520 case BIT:
521 splitrand(p);
522 /* fool repladdr into doing right number of operands */
9ad46604 523 if (p->op==CASE || p->op==PROBER || p->op==PROBEW) lastrand=regs[RT4];
c2a86b7c 524/* else if (p->op==CMPV || p->op==CMPZV) lastrand=regs[RT4+1]; */
9ad46604 525 else if (p->op==MOVC3) lastrand=regs[RT1];
f00d91fc
BJ		 526 else lastrand=regs[RT3];
527 repladdr(p);
528 if (p->op==CALLS || p->op==MOVC3) clearreg();
529 if (p->op==BIT) bitopt(p);
530 ccloc[0]=0; break;
531
532 case CBR:
533 if (p->subop>=JBC) {
534 splitrand(p);
535 if (p->subop<JBCC) lastrand=regs[RT3]; /* 2 operands can be optimized */
536 else lastrand=regs[RT2]; /* .mb destinations lose */
537 repladdr(p);
538 }
539 ccloc[0] = 0;
540 break;
541
542 case JBR:
543 redunbr(p);
544
545/* .wx,.bb */
546 case SOB:
547
548 default:
549 clearreg();
550 }
551 }
552}
553
554char *
555byondrd(p) register struct node *p; {
556/* return pointer to register which is "beyond last read/modify operand" */
557 if (OP2==(p->subop>>4)) return(regs[RT3]);
558 switch (p->op) {
559 case MFPR:
560 case JSB:
561 case PUSHA:
562 case TST: case INC: case DEC: case PUSH: return(regs[RT2]);
563 case MTPR:
564 case BIT: case CMP: case CALLS: return(regs[RT3]);
565 case PROBER: case PROBEW:
566 case CASE: case MOVC3: return(regs[RT4]);
567 }
568 return(lastrand);
569}
570
571struct node *
572bflow(p)
573register struct node *p;
574{
575 register char *cp1,*cp2,**preg; register int r;
576 int flow= -1;
577 struct node *olduse=0;
578 splitrand(p);
579 if (p->op!=PUSH && p->subop && 0<=(r=isreg(lastrand)) && r<NUSE && uses[r]==p->forw) {
580 if (equtype(p->subop,regs[r][0])
581 || ((p->op==CVT || p->op==MOVZ)
582 && 0xf&regs[r][0] && compat(0xf&(p->subop>>4),regs[r][0]))) {
583 register int r2;
584 if (regs[r][1]!=0) {/* send directly to destination */
585 if (p->op==INC || p->op==DEC) {
586 if (p->op==DEC) p->op=SUB; else p->op=ADD;
587 p->subop=(OP2<<4)+(p->subop&0xF); /* use 2 now, convert to 3 later */
588 p->pop=0;
589 cp1=lastrand; cp2=regs[RT2]; while (*cp2++= *cp1++); /* copy reg */
590 cp1=lastrand; *cp1++='$'; *cp1++='1'; *cp1=0;
591 }
592 cp1=regs[r]+1; cp2=lastrand;
593 if (OP2==(p->subop>>4)) {/* use 3 operand form of instruction */
594 p->pop=0;
595 p->subop += (OP3-OP2)<<4; lastrand=cp2=regs[RT3];
596 }
597 while (*cp2++= *cp1++);
598 if (p->op==MOVA && p->forw->op==PUSH) {
599 p->op=PUSHA; *regs[RT2]=0; p->pop=0;
600 } else if (p->op==MOV && p->forw->op==PUSH) {
601 p->op=PUSH ; *regs[RT2]=0; p->pop=0;
602 }
603 delnode(p->forw);
604 if (0<=(r2=isreg(lastrand)) && r2<NUSE) {
605 uses[r2]=uses[r]; uses[r]=0;
606 }
41feb04a 607 (void) redun3(p,0);
f00d91fc
BJ		 608 newcode(p); redunm++; flow=r;
609 } else if (p->op==MOV && p->forw->op!=EXTV && p->forw->op!=EXTZV) {
610 /* superfluous fetch */
611 int nmatch;
033bb901 612 char src[C2_ASIZE];
f00d91fc
BJ		 613 movit:
614 cp2=src; cp1=regs[RT1]; while (*cp2++= *cp1++);
615 splitrand(p->forw);
616 if (p->forw->op != INC && p->forw->op != DEC)
617 lastrand=byondrd(p->forw);
618 nmatch=0;
619 for (preg=regs+RT1;*preg!=lastrand;preg++)
620 if (r==isreg(*preg)) {
621 cp2= *preg; cp1=src; while (*cp2++= *cp1++); ++nmatch;
622 }
623 if (nmatch==1) {
624 if (OP2==(p->forw->subop>>4) && equstr(src,regs[RT2])) {
625 p->forw->pop=0;
626 p->forw->subop += (OP3-OP2)<<4; cp1=regs[RT3];
627 *cp1++='r'; *cp1++=r+'0'; *cp1=0;
628 }
629 delnode(p); p=p->forw;
630 if (0<=(r2=isreg(src)) && r2<NUSE) {
631 uses[r2]=uses[r]; uses[r]=0;
632 }
41feb04a 633 (void) redun3(p,0);
f00d91fc
BJ		 634 newcode(p); redunm++; flow=r;
635 } else splitrand(p);
636 }
637 } else if (p->op==MOV && (p->forw->op==CVT || p->forw->op==MOVZ)
638 && p->forw->subop&0xf /* if base or index, then forget it */
639 && compat(p->subop,p->forw->subop) && !source(cp1=regs[RT1])
640 && !indexa(cp1)) goto movit;
641 }
642 /* adjust 'lastrand' past any 'read' or 'modify' operands. */
643 lastrand=byondrd(p);
644 /* a 'write' clobbers the register. */
645 if (0<=(r=isreg(lastrand)) && r<NUSE
646 || OP2==(p->subop>>4) && 0<=(r=isreg(regs[RT2])) && r<NUSE && uses[r]==0) {
647 /* writing a dead register is useless, but watch side effects */
648 switch (p->op) {
35307d30 649 case ACB:
f00d91fc 650 case AOBLEQ: case AOBLSS: case SOBGTR: case SOBGEQ: break;
35307d30 651 default:
f00d91fc
BJ		 652 if (uses[r]==0) {/* no direct uses, check for use of condition codes */
653 register struct node *q=p;
654 while ((q=nonlab(q->forw))->combop==JBR) q=q->ref; /* cc unused, unchanged */
655 if (q->op!=CBR) {/* ... and destroyed */
656 preg=regs+RT1;
657 while (cp1= *preg++) {
658 if (cp1==lastrand) {redunm++; delnode(p); return(p->forw);}
659 if (source(cp1) || equstr(cp1,lastrand)) break;
660 }
661 }
662 }
663 flow=r;
664 }
665 }
41feb04a
RC		 666 if (0<=(r=flow)) {
667 olduse=uses[r];
668 uses[r]=0;
669 regs[r][0]=regs[r][1]=0;
670 }
f00d91fc
BJ		 671 /* these two are here, rather than in bmove(),
672 /* because I decided that it was better to go for 3-address code
673 /* (save time) rather than fancy jbxx (save 1 byte)
674 /* on sequences like bisl2 $64,r0; movl r0,foo
675 */
676 if (p->op==BIC) {p=bicopt(p); splitrand(p); lastrand=byondrd(p);}
41feb04a 677 if (p->op==BIS) {(void) bixprep(p,JBSS); lastrand=byondrd(p);}
f00d91fc
BJ		 678 /* now look for 'read' or 'modify' (read & write) uses */
679 preg=regs+RT1;
680 while (*(cp1= *preg++)) {
681 /* check for r */
682 if (lastrand!=cp1 && 0<=(r=isreg(cp1)) && r<NUSE && uses[r]==0) {
683 uses[r]=p; cp2=regs[r]; *cp2++=p->subop;
d1580951 684 if (p->op==ASH && preg==(regs+RT1+1)) cp2[-1]=BYTE; /* stupid DEC */
f00d91fc
BJ		 685 if (p->op==MOV || p->op==PUSH || p->op==CVT || p->op==MOVZ || p->op==COM || p->op==NEG) {
686 if (p->op==PUSH) cp1="-(sp)";
687 else {
688 cp1=regs[RT2];
689 if (0<=(r=isreg(cp1)) && r<NUSE && uses[r]==0)
690 uses[r]=olduse; /* reincarnation!! */
691 /* as in addl2 r0,r1; movl r1,r0; ret */
692 if (p->op!=MOV) cp1=0;
693 }
694 if (cp1) while (*cp2++= *cp1++);
d1580951
BJ		 695 else *cp2=0;
696 } else *cp2=0;
f00d91fc
BJ		 697 continue;
698 }
699 /* check for (r),(r)+,-(r),[r] */
700 do if (*cp1=='(' || *cp1=='[') {/* get register number */
701 char t;
702 cp2= ++cp1; while (*++cp1!=')' && *cp1!=']'); t= *cp1; *cp1=0;
703 if (0<=(r=isreg(cp2)) && r<NUSE && (uses[r]==0 || uses[r]==p)) {
704 uses[r]=p; regs[r][0]=(*--cp2=='[' ? OPX<<4 : OPB<<4);
705 }
706 *cp1=t;
707 } while (*++cp1);
708 }
709 /* pushax or movax possibility? */
710 cp1=regs[RT1];
711 if (*cp1++=='$' && isstatic(cp1) && natural(regs[RT1])) {
712 if (p->combop==T(MOV,LONG)) {
713 if (regs[RT1][1]=='L' && 0!=(p->labno=getnum(regs[RT1]+2))) {
714 cp1=p->code; while (*cp1++!=','); p->code= --cp1;
715 }
716 p->combop=T(MOVA,LONG); ++p->code; p->pop=0;
717 } else if (p->combop==T(PUSH,LONG)) {
718 p->combop=T(PUSHA,LONG); ++p->code; p->pop=0;
719 } else if ((p->combop&0xFFFF)==T(ADD,U(LONG,OP3))
720 && 0<=(r=isreg(regs[RT2]))) {
721 cp1=cp2=p->code; ++cp1;
722 do *cp2++= *cp1; while (*cp1++!=','); cp2[-1]='[';
723 do *cp2++= *cp1; while (*cp1++!=','); cp2[-1]=']';
724 if (!equstr(regs[RT3],"-(sp)")) p->combop=T(MOVA,BYTE);
725 else {p->combop=T(PUSHA,BYTE); *cp2=0;}
3464f46e
KM		 726 if (r < NUSE && uses[r] == 0) {
727 uses[r]=p;
728 regs[r][0]=OPX<<4;
729 }
f00d91fc
BJ		 730 p->pop=0;
731 }
732 }
733 return(p);
734}
735
736ispow2(n) register long n; {/* -1 -> no; else -> log to base 2 */
737 register int log;
738 if (n==0 || n&(n-1)) return(-1); log=0;
739 for (;;) {n >>= 1; if (n==0) return(log); ++log; if (n== -1) return(log);}
740}
741
742bitopt(p) register struct node *p; {
743 /* change "bitx $<power_of_2>,a" followed by JEQ or JNE
744 /* into JBC or JBS. watch out for I/O registers. (?)
745 /* assumes that 'splitrand' has already been called.
746 */
747 register char *cp1,*cp2; int b;
748 cp1=regs[RT1]; cp2=regs[RT2];
749 if (*cp1++!='$' || !okio(cp2) || p->forw->op!=CBR || p->forw->subop&-2 ||
f69fb1e7
DS		 750 0>(b=ispow2(getnum(cp1)))) return;
751 if (p->subop!=BYTE && !(b==0 && p->subop==LONG) &&
752 (source(cp2) || indexa(cp2))) return;
f00d91fc
BJ		 753 if (b>=bitsize[p->subop]) {/* you dummy! */
754 if (source(cp2)) {/* side effect: auto increment or decrement */
755 p->pop=0;
756 p->op=TST; --cp1; while (*cp1++= *cp2++);
757 regs[RT2][0]=0; newcode(p);
758 } else delnode(p);
759 p = p->forw;
760 if (p->subop==JEQ) {p->combop=JBR; p->pop=0;}
761 else delnode(p);
762 nchange++; nbj++; return;
763 }
764 if (cp1=p->forw->code) {/* destination is not an internal label */
765 cp2=regs[RT3]; while (*cp2++= *cp1++);
766 }
f69fb1e7
DS		 767 if (b==0 && (p->subop==LONG || !(source(regs[RT2]) || indexa(regs[RT2])))) {
768 /* JLB optimization, ala BLISS */
f00d91fc
BJ		 769 cp2=regs[RT1]; cp1=regs[RT2]; while (*cp2++= *cp1++);
770 cp2=regs[RT2]; cp1=regs[RT3]; while (*cp2++= *cp1++);
771 *(regs[RT3])=0; p->forw->subop += JLBC-JBC;
772 p->forw->pop=0;
773 } else {
774 cp1=regs[RT1]+1;
775 if (b>9) *cp1++= b/10 +'0'; *cp1++= b%10 +'0'; *cp1=0; /* $<bit_number> */
776 }
777 nbj++; newcode(p); p->combop = p->forw->combop+((JBC-JEQ)<<8);
778 p->labno = p->forw->labno; delnode(p->forw);
779 p->pop=0;
780}
781
782isfield(n) register long n; {/* -1 -> no; else -> position of low bit */
41feb04a 783 register int p; register long t;
f00d91fc 784 t= ((n-1)|n) +1;
eea63b82 785 if (n!=0 && (0==t || 0<=ispow2(t))) {
41feb04a 786 p=0; while(!(n&1)) {n >>= 1; ++p;} return(p);
f00d91fc
BJ		 787 } else return(-1);
788}
789
790bixprep(p,bix) register struct node *p; {
791/* initial setup, single-bit checking for bisopt, bicopt.
792/* return: 0->don't bother any more; 1->worthwhile trying
793*/
794 register char *cp1,*cp2;
795 splitrand(p); cp1=regs[RT1]; cp2=regs[RT2];
796 if (*cp1++!='$' || 0>(pos=isfield(f=getnum(cp1)))
797 || !okio(cp2) || indexa(cp2) || source(cp2) || !okio(lastrand)) return(0);
798 f |= f-1; if (++f==0) siz=32-pos; else siz=ispow2(f)-pos;
799 if (siz==1 && pos>5 && (p->subop>>4)==OP2 && (p->subop&0xF)!=BYTE
800 && pos<bitsize[p->subop&0xF]) {
801 p->ref = insertl(p->forw); p->combop = CBR | (bix<<8);
802 p->pop=0;
803 p->labno = p->ref->labno;
804 if (pos>9) {*cp1++= pos/10 +'0'; pos %= 10;}
805 *cp1++=pos+'0'; *cp1=0; newcode(p); nbj++; return(0);
806 }
807 return(1);
808}
809
810
811struct node *
812bicopt(p) register struct node *p; {
813/* use field operations or MOVZ if possible. done as part of 'bflow'.
814*/
815 register char *cp1,*cp2; int r;
3b60efae 816 char src[C2_ASIZE];
41feb04a 817 char lhssiz, sop;
f00d91fc
BJ		 818 if (!bixprep(p,JBCC)) return(p);
819 if (f==0) {/* the BIC isolates low order bits */
820 siz=pos; pos=0;
821 if ((p->subop&0xF)==LONG && *(regs[RT2])!='$') {/* result of EXTZV is long */
822 /* save source of BICL in 'src' */
823 cp1=regs[RT2]; cp2=src; while (*cp2++= *cp1++);
824 if (p->back->op==ASH) {/* try for more */
825 splitrand(p->back); cp1=regs[RT1]; cp2=regs[RT3];
826 if (*cp1++=='$' && *(regs[RT2])!='$' && !indexa(regs[RT2])
827 && 0>(f=getnum(cp1)) && equstr(src,cp2)
eea63b82
RC		 828 && 0<=(r=isreg(cp2)) && r<NUSE
829 && siz-f <= 32) { /* a good ASH */
f00d91fc
BJ		 830 pos -= f; cp1=regs[RT2]; cp2=src; while (*cp2++= *cp1++);
831 delnode(p->back);
832 }
833 }
49c27f9c
RC		 834 /*
835 * 'pos', 'siz' known; find out the size of the
836 * left-hand operand of what the bicl will turn into.
837 */
838 if (pos==0 && siz==16)
839 lhssiz = WORD; /* movzwl */
840 else
841 lhssiz = BYTE; /* movzbl or extzvl */
f00d91fc
BJ		 842 if (p->back->op==CVT || p->back->op==MOVZ) {/* greedy, aren't we? */
843 splitrand(p->back); cp1=regs[RT1]; cp2=regs[RT2];
49c27f9c
RC		 844 /*
845 * If indexa(cp1) || autoid(cp1), the fold may
846 * still be OK if the CVT/MOVZ has the same
847 * size operand on its left size as what we
848 * will turn the bicl into.
849 * However, if the CVT is from a float or
850 * double, forget it!
851 */
41feb04a 852 sop = p->back->subop&0xF; /* type of LHS of CVT/MOVZ */
49c27f9c 853 if (equstr(src,cp2) && okio(cp1)
41feb04a
RC		 854 && sop != FFLOAT && sop != DFLOAT
855 && sop != GFLOAT && sop != HFLOAT
856 && ((!indexa(cp1) && !autoid(cp1)) || lhssiz == sop)
f00d91fc 857 && 0<=(r=isreg(cp2)) && r<NUSE
41feb04a 858 && bitsize[sop]>=(pos+siz)
f00d91fc
BJ		 859 && bitsize[p->back->subop>>4]>=(pos+siz)) {/* good CVT */
860 cp1=regs[RT1]; cp2=src; while (*cp2++= *cp1++);
861 delnode(p->back);
862 }
863 }
864 /* 'pos', 'siz' known; source of field is in 'src' */
865 splitrand(p); /* retrieve destination of BICL */
49c27f9c
RC		 866 if ((siz==8 || siz==16) && pos==0) {
867 p->combop = T(MOVZ,U(lhssiz,LONG));
f00d91fc
BJ		 868 sprintf(line,"%s,%s",src,lastrand);
869 } else {
870 p->combop = T(EXTZV,LONG);
871 sprintf(line,"$%d,$%d,%s,%s",pos,siz,src,lastrand);
872 }
873 p->pop=0;
874 p->code = copy(line); nfield++; return(p);
875 }/* end EXTZV possibility */
876 }/* end low order bits */
877/* unfortunately, INSV clears the condition codes, thus cannot be used */
878/* else {/* see if BICL2 of positive field should be INSV $0 */
879/* if (p->subop==(LONG | (OP2<<4)) && 6<=(pos+siz)) {
880/* p->combop = INSV;
881/* sprintf(line,"$0,$%d,$%d,%s",pos,siz,lastrand);
882/* p->code = copy(line); nfield++; return(p);
883/* }
884/* }
885*/
886 return(p);
887}
888
889jumpsw()
890{
891 register struct node *p, *p1;
41feb04a
RC		 892 register struct node *tp;
893 long tl;
894 char *tcp;
895 int ti;
f00d91fc
BJ		 896 int nj;
897
41feb04a 898 ti = 0;
f00d91fc
BJ		 899 nj = 0;
900 for (p=first.forw; p!=0; p = p->forw)
41feb04a 901 p->seq = ++ti;
f00d91fc
BJ		 902 for (p=first.forw; p!=0; p = p1) {
903 p1 = p->forw;
904 if (p->op == CBR && p1->op==JBR && p->ref && p1->ref
905 && abs(p->seq - p->ref->seq) > abs(p1->seq - p1->ref->seq)) {
906 if (p->ref==p1->ref)
907 continue;
908 p->subop = revbr[p->subop];
909 p->pop=0;
41feb04a 910 tp = p1->ref;
f00d91fc 911 p1->ref = p->ref;
41feb04a
RC		 912 p->ref = tp;
913 tl = p1->labno;
f00d91fc 914 p1->labno = p->labno;
41feb04a 915 p->labno = tl;
f00d91fc
BJ		 916#ifdef COPYCODE
917 if (p->labno == 0) {
41feb04a
RC		 918 tcp = p1->code;
919 p1->code = p->code;
920 p->code = tcp;
f00d91fc
BJ		 921 }
922#endif
923 nrevbr++;
924 nj++;
925 }
926 }
927 return(nj);
928}
929
930addsob()
931{
932 register struct node *p, *p1, *p2, *p3;
933
934 for (p = &first; (p1 = p->forw)!=0; p = p1) {
935 if (p->combop==T(DEC,LONG) && p1->op==CBR) {
3b60efae 936 if (abs(p->seq - p1->ref->seq) > 8) continue;
f00d91fc
BJ		 937 if (p1->subop==JGE || p1->subop==JGT) {
938 if (p1->subop==JGE) p->combop=SOBGEQ; else p->combop=SOBGTR;
939 p->pop=0;
940 p->labno = p1->labno; delnode(p1); nsob++;
941 }
942 } else if (p->combop==T(INC,LONG)) {
943 if (p1->op==LABEL && p1->refc==1 && p1->forw->combop==T(CMP,LONG)
944 && (p2=p1->forw->forw)->combop==T(CBR,JLE)
945 && (p3=p2->ref->back)->combop==JBR && p3->ref==p1
946 && p3->forw->op==LABEL && p3->forw==p2->ref) {
947 /* change INC LAB: CMP to LAB: INC CMP */
948 p->back->forw=p1; p1->back=p->back;
949 p->forw=p1->forw; p1->forw->back=p;
950 p->back=p1; p1->forw=p;
951 p1=p->forw;
952 /* adjust beginning value by 1 */
953 p2=alloc(sizeof first); p2->combop=T(DEC,LONG);
954 p2->pop=0;
955 p2->forw=p3; p2->back=p3->back; p3->back->forw=p2;
956 p3->back=p2; p2->code=p->code; p2->labno=0;
957 }
958 if (p1->combop==T(CMP,LONG) && (p2=p1->forw)->op==CBR) {
959 register char *cp1,*cp2;
960 splitrand(p1); if (!equstr(p->code,regs[RT1])) continue;
3b60efae 961 if (abs(p->seq - p2->ref->seq)>8) {/* outside byte displ range */
f00d91fc
BJ		 962 if (p2->subop!=JLE) continue;
963 p->combop=T(ACB,LONG);
964 cp2=regs[RT1]; cp1=regs[RT2]; while (*cp2++= *cp1++); /* limit */
965 cp2=regs[RT2]; cp1="$1"; while (*cp2++= *cp1++); /* increment */
966 cp2=regs[RT3]; cp1=p->code; while (*cp2++= *cp1++); /* index */
967 p->pop=0; newcode(p);
968 p->labno = p2->labno; delnode(p2); delnode(p1); nsob++;
969 } else if (p2->subop==JLE || p2->subop==JLT) {
970 if (p2->subop==JLE) p->combop=AOBLEQ; else p->combop=AOBLSS;
971 cp2=regs[RT1]; cp1=regs[RT2]; while (*cp2++= *cp1++); /* limit */
972 cp2=regs[RT2]; cp1=p->code; while (*cp2++= *cp1++); /* index */
973 p->pop=0; newcode(p);
974 p->labno = p2->labno; delnode(p2); delnode(p1); nsob++;
975 }
976 }
977 }
978 }
979}
980
f00d91fc
BJ		 981equop(p1, p2)
982register struct node *p1;
983struct node *p2;
984{
985 register char *cp1, *cp2;
986
987 if (p1->combop != p2->combop)
988 return(0);
989 if (p1->op>0 && p1->op<MOV)
990 return(0);
41feb04a
RC		 991 switch (p1->combop) {
992 case EROU: case JSW: case TEXT: case DATA:
993 case BSS: case ALIGN: case WGEN: case END:
994 /*
995 * Consider all pseudo-ops to be unique.
996 */
997 return(0);
998 }
f00d91fc
BJ		 999 if (p1->op==MOVA && p1->labno!=p2->labno) return(0);
1000 cp1 = p1->code;
1001 cp2 = p2->code;
1002 if (cp1==0 && cp2==0)
1003 return(1);
1004 if (cp1==0 || cp2==0)
1005 return(0);
1006 while (*cp1 == *cp2++)
1007 if (*cp1++ == 0)
1008 return(1);
1009 return(0);
1010}
1011
41feb04a 1012#ifndef delnode
f00d91fc
BJ		 1013delnode(p) register struct node *p; {
1014 p->back->forw = p->forw;
1015 p->forw->back = p->back;
1016}
41feb04a 1017#endif
f00d91fc 1018
41feb04a 1019#ifndef decref
f00d91fc
BJ		 1020decref(p)
1021register struct node *p;
1022{
1023 if (p && --p->refc <= 0) {
1024 nrlab++;
1025 delnode(p);
1026 }
1027}
41feb04a 1028#endif
f00d91fc
BJ		 1029
1030struct node *
1031nonlab(ap)
1032struct node *ap;
1033{
1034 register struct node *p;
1035
1036 p = ap;
1037 while (p && p->op==LABEL)
1038 p = p->forw;
1039 return(p);
1040}
1041
1042clearuse() {
1043 register struct node **i;
1044 for (i=uses+NUSE; i>uses;) *--i=0;
1045}
1046
1047clearreg() {
41feb04a
RC		 1048 register char **i;
1049 for (i=regs; i<regs+NREG; ++i) {
1050 **i = 0;
1051 *(*i+1) = 0;
1052 }
1053 conloc[0] = 0;
1054 ccloc[0] = 0;
f00d91fc
BJ		 1055}
1056
1057savereg(ai, s, type)
1058register char *s;
1059{
1060 register char *p, *sp;
1061
1062 sp = p = regs[ai];
1063 if (source(s)) /* side effects in addressing */
1064 return;
1065 /* if any indexing, must be parameter or local */
1066 /* indirection (as in "*-4(fp)") is ok, however */
1067 *p++ = type;
1068 while (*p++ = *s)
1069 if (*s=='[' || *s++=='(' && *s!='a' && *s!='f') {*sp = 0; return;}
1070}
1071
1072dest(s,type)
1073register char *s;
1074{
1075 register int i;
1076
41feb04a 1077 (void) source(s); /* handle addressing side effects */
6b028d93
RC		 1078 if (!natural(s)) {
1079 /* wild store, everything except constants vanishes */
1080 for (i=NREG; --i>=0;)
41feb04a
RC		 1081 if (regs[i][1] != '$')
1082 regs[i][0] = regs[i][1] = 0;
6b028d93
RC		 1083 conloc[0] = 0; ccloc[0] = 0;
1084 return;
1085 }
f00d91fc 1086 if ((i = isreg(s)) >= 0) {
41feb04a
RC		 1087 /* if register destination, that reg is a goner */
1088 regs[i][0] = regs[i][1] = 0;
0594fe30
BJ		 1089 switch(type & 0xF){
1090 case DFLOAT: /* clobber two at once */
1091 /*FALLTHROUGH*/
1092 case GFLOAT:
41feb04a 1093 regs[i+1][0] = regs[i+1][1] = 0;
0594fe30
BJ		 1094 break;
1095 case HFLOAT: /* clobber four at once */
41feb04a
RC		 1096 regs[i+1][0] = regs[i+1][1] = 0;
1097 regs[i+2][0] = regs[i+2][1] = 0;
1098 regs[i+3][0] = regs[i+3][1] = 0;
0594fe30
BJ		 1099 break;
1100 }
1101 switch((type>>4)&0xF){
1102 case DFLOAT: /* clobber two at once */
1103 /*FALLTHROUGH*/
1104 case GFLOAT:
41feb04a 1105 regs[i+1][0] = regs[i+1][1] = 0;
0594fe30
BJ		 1106 break;
1107 case HFLOAT: /* clobber four at once */
41feb04a
RC		 1108 regs[i+1][0] = regs[i+1][1] = 0;
1109 regs[i+2][0] = regs[i+2][1] = 0;
1110 regs[i+3][0] = regs[i+3][1] = 0;
0594fe30
BJ		 1111 break;
1112 }
f00d91fc
BJ		 1113 }
1114 for (i=NREG; --i>=0;)
1115 if (regs[i][1]=='*' && equstr(s, regs[i]+2))
41feb04a 1116 regs[i][0] = regs[i][1] = 0; /* previous indirection through destination is invalid */
f00d91fc 1117 while ((i = findrand(s,0)) >= 0) /* previous values of destination are invalid */
41feb04a 1118 regs[i][0] = regs[i][1] = 0;
6b028d93
RC		 1119 if (*conloc && equstr(conloc, s))
1120 conloc[0] = 0;
1121 setcc(s, type); /* natural destinations set condition codes */
f00d91fc
BJ		 1122}
1123
f00d91fc 1124/* separate operands at commas, set up 'regs' and 'lastrand' */
6b028d93
RC		 1125splitrand(p) struct node *p; {
1126 register char *p1, *p2;
1127 register char **preg;
1128
1129 preg = regs+RT1;
1130 if (p1 = p->code)
1131 while (*p1) {
1132 lastrand = p2 = *preg++;
1133 while (*p1)
1134 if (',' == (*p2++ = *p1++)) {
1135 --p2;
1136 break;
1137 }
1138 *p2 = 0;
1139 }
1140 while (preg < (regs+RT1+5))
1141 *(*preg++) = 0;
f00d91fc
BJ		 1142}
1143
1144compat(have, want) {
1145register int hsrc, hdst;
1146if (0==(want &= 0xF)) return(1); /* anything satisfies a wildcard want */
cdd0bda3
DS		 1147hsrc=have&0xF;
1148if (0==(hdst=((have>>4)&0xF)) || (hdst>=OP2 && hdst<=OPX)) hdst=hsrc;
0594fe30
BJ		 1149if (want>=FFLOAT) return(hdst==want && hsrc==want);
1150 /* FLOAT, DFLOAT not compat: rounding */
1151return(hsrc>=want && hdst>=want && hdst<FFLOAT);
f00d91fc
BJ		 1152}
1153
1154equtype(t1,t2) {return(compat(t1,t2) && compat(t2,t1));}
1155
1156findrand(as, type)
1157char *as;
1158{
1159 register char **i;
1160 for (i = regs+NREG; --i>=regs;) {
1161 if (**i && equstr(*i+1, as) && compat(**i,type))
1162 return(i-regs);
1163 }
1164 return(-1);
1165}
1166
1167isreg(s)
1168register char *s;
1169{
1170 if (*s++!='r' || !isdigit(*s++)) return(-1);
1171 if (*s==0) return(*--s-'0');
1172 if (*(s-1)=='1' && isdigit(*s++) && *s==0) return(10+*--s-'0');
1173 return(-1);
1174}
1175
1176check()
1177{
1178 register struct node *p, *lp;
1179
1180 lp = &first;
1181 for (p=first.forw; p!=0; p = p->forw) {
41feb04a
RC		 1182 if (p->back != lp) {
1183 fprintf(stderr, "c2: failed internal consistency check -- help!\n");
1184 exit(-1);
1185 }
f00d91fc
BJ		 1186 lp = p;
1187 }
1188}
1189
1190source(ap)
1191char *ap;
1192{
1193 register char *p1, *p2;
1194
1195 p1 = ap;
1196 p2 = p1;
1197 if (*p1==0)
1198 return(0);
1199 while (*p2++ && *(p2-1)!='[');
1200 if (*p1=='-' && *(p1+1)=='('
1201 || *p1=='*' && *(p1+1)=='-' && *(p1+2)=='('
1202 || *(p2-2)=='+') {
1203 while (*p1 && *p1++!='r');
1204 if (isdigit(*p1++))
41feb04a
RC		 1205 if (isdigit(*p1))
1206 regs[10+*p1-'0'][0] = regs[10+*p1-'0'][1] = 0;
1207 else {
1208 --p1;
1209 regs[*p1-'0'][0] = regs[*p1-'0'][1] = 0;
1210 }
f00d91fc
BJ		 1211 return(1);
1212 }
1213 return(0);
1214}
1215
1216newcode(p) struct node *p; {
1217 register char *p1,*p2,**preg;
1218 preg=regs+RT1; p2=line;
1219 while (*(p1= *preg++)) {while (*p2++= *p1++); *(p2-1)=',';}
1220 *--p2=0;
1221 p->code=copy(line);
1222}
1223
1224repladdr(p)
1225struct node *p;
1226{
1227 register r;
41feb04a 1228 register char *p1;
f00d91fc
BJ		 1229 char **preg; int nrepl;
1230
1231 preg=regs+RT1; nrepl=0;
1232 while (lastrand!=(p1= *preg++))
1233 if (!source(p1) && 0<=(r=findrand(p1,p->subop))) {
1234 *p1++='r'; if (r>9) {*p1++='1'; r -= 10;} *p1++=r+'0'; *p1=0;
1235 nrepl++; nsaddr++;
1236 }
1237 if (nrepl) newcode(p);
1238}
1239
1240/* movedat()
1241/* {
1242/* register struct node *p1, *p2;
1243/* struct node *p3;
1244/* register seg;
1245/* struct node data;
1246/* struct node *datp;
1247/*
1248/* if (first.forw == 0)
1249/* return;
1250/* datp = &data;
1251/* for (p1 = first.forw; p1!=0; p1 = p1->forw) {
1252/* if (p1->op == DATA) {
1253/* p2 = p1->forw;
1254/* while (p2 && p2->op!=TEXT)
1255/* p2 = p2->forw;
1256/* if (p2==0)
1257/* break;
1258/* p3 = p1->back;
1259/* p1->back->forw = p2->forw;
1260/* p2->forw->back = p3;
1261/* p2->forw = 0;
1262/* datp->forw = p1;
1263/* p1->back = datp;
1264/* p1 = p3;
1265/* datp = p2;
1266/* }
1267/* }
1268/* if (data.forw) {
1269/* datp->forw = first.forw;
1270/* first.forw->back = datp;
1271/* data.forw->back = &first;
1272/* first.forw = data.forw;
1273/* }
1274/* seg = -1;
1275/* for (p1 = first.forw; p1!=0; p1 = p1->forw) {
1276/* if (p1->op==TEXT||p1->op==DATA||p1->op==BSS) {
1277/* if (p1->op == seg || p1->forw&&p1->forw->op==seg) {
1278/* p1->back->forw = p1->forw;
1279/* p1->forw->back = p1->back;
1280/* p1 = p1->back;
1281/* continue;
1282/* }
1283/* seg = p1->op;
1284/* }
1285/* }
1286/* }
1287*/
1288
1289redunbr(p)
1290register struct node *p;
1291{
1292 register struct node *p1;
1293 register char *ap1;
1294 char *ap2;
1295
1296 if ((p1 = p->ref) == 0)
1297 return;
1298 p1 = nonlab(p1);
1299 if (p1->op==TST) {
1300 splitrand(p1);
1301 savereg(RT2, "$0", p1->subop);
1302 } else if (p1->op==CMP)
1303 splitrand(p1);
1304 else
1305 return;
1306 if (p1->forw->op==CBR) {
1307 ap1 = findcon(RT1, p1->subop);
1308 ap2 = findcon(RT2, p1->subop);
1309 p1 = p1->forw;
1310 if (compare(p1->subop, ap1, ap2)) {
1311 nredunj++;
1312 nchange++;
1313 decref(p->ref);
1314 p->ref = p1->ref;
1315 p->labno = p1->labno;
1316#ifdef COPYCODE
1317 if (p->labno == 0)
1318 p->code = p1->code;
f00d91fc 1319#endif
6b028d93 1320 if (p->ref)
f00d91fc
BJ		 1321 p->ref->refc++;
1322 }
1323 } else if (p1->op==TST && equstr(regs[RT1],ccloc+1) &&
1324 equtype(ccloc[0],p1->subop)) {
1325 p1=insertl(p1->forw); decref(p->ref); p->ref=p1;
1326 nrtst++; nchange++;
1327 }
1328}
1329
1330char *
1331findcon(i, type)
1332{
1333 register char *p;
1334 register r;
1335
1336 p = regs[i];
1337 if (*p=='$')
1338 return(p);
1339 if ((r = isreg(p)) >= 0 && compat(regs[r][0],type))
1340 return(regs[r]+1);
1341 if (equstr(p, conloc))
1342 return(conval+1);
1343 return(p);
1344}
1345
41feb04a 1346compare(opc, acp1, acp2)
f00d91fc
BJ		 1347char *acp1, *acp2;
1348{
1349 register char *cp1, *cp2;
1350 register n1;
1351 int n2; int sign;
1352
1353 cp1 = acp1;
1354 cp2 = acp2;
1355 if (*cp1++ != '$' || *cp2++ != '$')
1356 return(0);
1357 n1 = 0; sign=1; if (*cp2=='-') {++cp2; sign= -1;}
1358 while (isdigit(*cp2)) {n1 *= 10; n1 += (*cp2++ - '0')*sign;}
1359 n2 = n1;
1360 n1 = 0; sign=1; if (*cp1=='-') {++cp1; sign= -1;}
1361 while (isdigit(*cp1)) {n1 *= 10; n1 += (*cp1++ - '0')*sign;}
1362 if (*cp1=='+')
1363 cp1++;
1364 if (*cp2=='+')
1365 cp2++;
1366 do {
1367 if (*cp1++ != *cp2)
1368 return(0);
1369 } while (*cp2++);
41feb04a 1370 switch(opc) {
f00d91fc
BJ		 1371
1372 case JEQ:
41feb04a 1373 return(n1 == n2);
f00d91fc 1374 case JNE:
41feb04a 1375 return(n1 != n2);
f00d91fc 1376 case JLE:
41feb04a 1377 return(n1 <= n2);
f00d91fc 1378 case JGE:
41feb04a 1379 return(n1 >= n2);
f00d91fc 1380 case JLT:
41feb04a 1381 return(n1 < n2);
f00d91fc 1382 case JGT:
41feb04a 1383 return(n1 > n2);
f00d91fc 1384 case JLO:
41feb04a 1385 return((unsigned) n1 < (unsigned) n2);
f00d91fc 1386 case JHI:
41feb04a 1387 return((unsigned) n1 > (unsigned) n2);
f00d91fc 1388 case JLOS:
41feb04a 1389 return((unsigned) n1 <= (unsigned) n2);
f00d91fc 1390 case JHIS:
41feb04a 1391 return((unsigned) n1 >= (unsigned) n2);
f00d91fc
BJ		 1392 }
1393 return(0);
1394}
1395
1396setcon(cv, cl, type)
1397register char *cv, *cl;
1398{
1399 register char *p;
1400
1401 if (*cv != '$')
1402 return;
1403 if (!natural(cl))
1404 return;
1405 p = conloc;
1406 while (*p++ = *cl++);
1407 p = conval;
1408 *p++ = type;
1409 while (*p++ = *cv++);
1410}
1411
1412equstr(p1, p2)
1413register char *p1, *p2;
1414{
1415 do {
1416 if (*p1++ != *p2)
1417 return(0);
1418 } while (*p2++);
1419 return(1);
1420}
1421
1422setcc(ap,type)
1423char *ap;
1424{
1425 register char *p, *p1;
1426
1427 p = ap;
1428 if (!natural(p)) {
1429 ccloc[0] = 0;
1430 return;
1431 }
1432 p1 = ccloc;
1433 *p1++ = type;
1434 while (*p1++ = *p++);
1435}
1436
1437okio(p) register char *p; {/* 0->probable I/O space address; 1->not */
1438 if (ioflag && (!natural(p) || 0>getnum(p))) return(0);
1439 return(1);
1440}
1441
1442indexa(p) register char *p; {/* 1-> uses [r] addressing mode; 0->doesn't */
1443 while (*p) if (*p++=='[') return(1);
1444 return(0);
1445}
1446
1447natural(p)
1448register char *p;
1449{/* 1->simple local, parameter, global, or register; 0->otherwise */
6b028d93 1450 if (*p=='*' || *p=='(' || *p=='-'&&p[1]=='(' || *p=='$'&&getnum(p+1))
f00d91fc
BJ		 1451 return(0);
1452 while (*p++);
1453 p--;
6b028d93 1454 if (*--p=='+' || *p==']' || *p==')' && p[-2]!='a' && p[-2]!='f')
f00d91fc
BJ		 1455 return(0);
1456 return(1);
1457}
1458
1459/*
1460** Tell if an argument is most likely static.
1461*/
1462
1463isstatic(cp)
1464register char *cp;
1465{
1466 if (*cp == '_' || *cp == 'L' || (*cp++ == 'v' && *cp == '.'))
1467 return (1);
1468 return (0);
1469}
49c27f9c
RC		 1470
1471autoid(p) register char *p; {/* 1-> uses autoincrement/autodecrement; 0->doesn't */
1472 if (*p == '-' && *(p+1) == '(') return(1);
1473 while (*p) p++;
1474 if (*--p == '+' && *--p == ')') return(1);
1475 return(0);
1476 }
Continuous source code history from original PDP-7 UNIX to FreeBSD 2, the first fully unencumbered FreeBSD release.