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try one more time to do it right
[unix-history] / usr / src / old / pcc / c2.vax / c21.c
CommitLineData
0594fe30 1static char sccsid[] = "@(#)c21.c 4.8 %G%";
35307d30 2/* char C21[] = {"@(#)c21.c 1.83 80/10/16 21:18:22 JFR"}; /* sccs ident */
f00d91fc
BJ		 3
4/*
5 * C object code improver-- second part
6 */
7
8#include "c2.h"
9#include <stdio.h>
10#include <ctype.h>
11
12#define NUSE 6
13int ioflag;
14int biti[NUSE] = {1,2,4,8,16,32};
0594fe30
BJ		 15int bitsize[] = { /* index by type codes */
16 0, /* not allocated */
17 8, /* BYTE */
18 16, /* WORD */
19 32, /* LONG */
20 32, /* FFLOAT /
21 64, /* DFLOAT */
22 64, /* GFLOAT */
23 128, /* HFLOAT */
24 64, /* QUAD */
25 128, /* OCTA */
26 0, /* OP2 */
27 0, /* OP3 */
28 0, /* OPB */
29 0 /* OPX */
30};
f00d91fc
BJ		 31int pos,siz; long f; /* for bit field communication */
32struct node *uses[NUSE]; /* for backwards flow analysis */
33char *lastrand; /* last operand of instruction */
34struct node *bflow();
35struct node *bicopt();
36char *findcon();
37
38redun3(p,split) register struct node *p; int split; {
39/* check for 3 addr instr which should be 2 addr */
40 if (OP3==((p->subop>>4)&0xF)) {
41 if (split) splitrand(p);
42 if (equstr(regs[RT1],regs[RT3])
43 && (p->op==ADD || p->op==MUL || p->op==BIS || p->op==XOR)) {
44 register char *t=regs[RT1]; regs[RT1]=regs[RT2]; regs[RT2]=t;
45 }
46 if (equstr(regs[RT2],regs[RT3])) {
47 p->subop=(p->subop&0xF)|(OP2<<4); p->pop=0;
48 lastrand=regs[RT2]; *regs[RT3]=0; return(1);
49 }
50 } return(0);
51}
52
53bmove() {
54 register struct node *p, *lastp; register char *cp1,*cp2; register int r;
55 refcount();
56 for (p=lastp= &first; 0!=(p=p->forw); lastp=p);
57 clearreg(); clearuse();
58 for (p=lastp; p!= &first; p=p->back) {
59 if (debug) {
60 printf("Uses:\n");
61 for (r=NUSE;--r>=0;) if (uses[r])
62 printf("%d: %s\n",r,uses[r]->code? uses[r]->code:"");
63 printf("-\n");
64 }
65 r=(p->subop>>4)&0xF;
66 if (OP2==r && (cp1=p->code, *cp1++)=='$' && *cp1++=='0' && *cp1++==',' &&
67 !source(cp1)) {/* a no-op unless MUL or DIV */
68 if (p->op==MUL) {p->op=MOV; p->subop&=0xF; p->pop=0;}
69 else if (p->op==DIV) fprintf(stderr,"c2: zero divide\n");
70 else {delnode(p); redunm++; continue;}
71 }
72 if (OP3==r && 0!=redun3(p,1)) {newcode(p); redunm++;}
73 switch (p->op) {
74 case LABEL: case DLABEL:
75 for (r=NUSE; --r>=0;)
76 if (uses[r]) p->ref=(struct node *) (((int)p->ref)|biti[r]);
77 break;
78 case CALLS:
79 clearuse(); goto std;
80 case 0:
81 clearuse(); break;
82 case SUB:
83 if ((p->subop&0xF)!=LONG) goto std; cp1=p->code;
84 if (*cp1++!='$') goto std; splitrand(p);
85 if (equstr(regs[RT2],"fp") && !indexa(regs[RT1])) {/* address comp. */
3b60efae 86 char buf[C2_ASIZE]; cp2=buf; *cp2++='-';
f00d91fc
BJ		 87 cp1=regs[RT1]+1; while (*cp2++= *cp1++); --cp2;
88 cp1="(fp),"; while (*cp2++= *cp1++); --cp2;
89 cp1=regs[RT3]; while (*cp2++= *cp1++);
90 p->code=copy(buf); p->combop=T(MOVA,LONG); p->pop=0;
91 } else if (*cp1++=='-' && 0<=(r=getnum(cp1))) {
92 p->op=ADD; p->pop=0; *--cp1='$'; p->code=cp1;
93 } goto std;
94 case ADD:
95 if ((p->subop&0xF)!=LONG) goto std; cp1=p->code;
96 if (*cp1++!='$') goto std; splitrand(p);
97 if (isstatic(cp1) && (r=isreg(regs[RT2]))>=0 && r<NUSE && uses[r]==p->forw)
98 {
99 /* address comp:
100 ** addl2 $_foo,r0 \ movab _foo[r0],bar
101 ** movl r0,bar /
102 */
103 register struct node *pnext = p->forw;
3b60efae 104 char buf[C2_ASIZE];
f00d91fc
BJ		 105
106 if (pnext->op == MOV && pnext->subop == LONG)
107 {
108 cp1 = &regs[RT1][1]; cp2 = &buf[0];
109 while (*cp2++ = *cp1++) ; cp2--;
110 splitrand(pnext);
111 if (r == isreg(regs[RT1]))
112 {
113 delnode(p); p = pnext;
114 p->op = MOVA; p->subop = BYTE;
115 p->pop = 0;
116 cp1 = regs[RT1]; *cp2++ = '[';
117 while (*cp2++ = *cp1++) ; cp2--;
118 *cp2++ = ']'; *cp2++ = ',';
119 cp1 = regs[RT2];
120 while (*cp2++ = *cp1++) ;
121 p->code = copy(buf);
122 }
123 }
124 }
125 else
126 if (equstr(regs[RT2],"fp") && !indexa(regs[RT1])) {/* address comp. */
127 cp2=cp1-1; cp1=regs[RT1]+1; while (*cp2++= *cp1++); --cp2;
128 cp1="(fp)"; while (*cp2++= *cp1++); *--cp2=',';
129 p->combop=T(MOVA,LONG); p->pop=0;
130 } else if (*cp1++=='-' && 0<=(r=getnum(cp1))) {
131 p->op=SUB; p->pop=0; *--cp1='$'; p->code=cp1;
132 }
133 /* fall thru ... */
134 case CASE:
135 default: std:
136 p=bflow(p); break;
137 case MUL:
138 {
139 /*
140 ** Change multiplication by constant powers of 2 to
141 ** shifts.
142 */
143 splitrand(p);
144 if (regs[RT1][0] != '$' || regs[RT1][1] == '-') goto std;
145 if ((r = ispow2(getnum(&regs[RT1][1]))) < 0) goto std;
146 switch (r)
147 {
148 case 0: /* mull3 $1,x,y */
149 if (p->subop == U(LONG,OP3))
150 {
151 if (equstr(regs[RT2], regs[RT3]))
152 {
153 delnode(p); p = p->forw;
154 }
155 else
156 {
157 p->op = MOV; p->subop = LONG;
158 p->pop = 0; newcode(p); nchange++;
159 }
160 }
161 else
162 if (p->subop == U(LONG,OP2))
163 {
164 delnode(p); p = p->forw;
165 }
166 goto std;
167
168 case 1: /* mull2 $2,x */
169 if (p->subop == U(LONG, OP2) && !source(regs[RT2]))
170 {
171 strcpy(regs[RT1], regs[RT2]);
172 p->op = ADD; p->pop = 0; newcode(p); nchange++;
173 }
174 goto std;
175 }
176 if(p->subop==U(LONG,OP3)||(p->subop==U(LONG,OP2)&&!source(regs[RT2])))
177 {
178 if (p->subop == U(LONG,OP2))
179 strcpy(regs[RT3], regs[RT2]);
180 sprintf(regs[RT1], "$%d", r);
181 p->op = ASH; p->subop = LONG;
182 p->pop = 0; newcode(p); nchange++;
183 }
184 goto std;
185 }
186 case ASH:
187 {
188 /* address comp:
189 ** ashl $1,bar,r0 \ movl bar,r0
190 ** movab _foo[r0] / movaw _foo[r0]
191 **
192 ** ashl $2,r0,r0 \ moval _foo[r0]
193 ** movab _foo[r0] /
194 */
195 register struct node *pf;
196 register int shfrom, shto;
197 long shcnt;
198 char *regfrom;
199
200 splitrand(p);
201 if (regs[RT1][0] != '$') goto std;
202 if ((shcnt = getnum(&regs[RT1][1])) < 1 || shcnt > 3) goto std;
203 if ((shfrom = isreg(regs[RT2])) >= 0)
204 regfrom = copy(regs[RT2],"]");
205 if ((shto = isreg(regs[RT3])) >= 0 && shto<NUSE)
206 {
207 int regnum;
208
209 if (uses[shto] != (pf = p->forw)) goto ashadd;
210 if (pf->op != MOVA && pf->op != PUSHA) goto ashadd;
211 if (pf->subop != BYTE) goto ashadd;
212 splitrand(pf);
213 if (!indexa(regs[RT1])) goto std;
214 cp2 = regs[RT1];
215 if(!isstatic(cp2)) goto std;
216 while (*cp2++ != '[') ;
217 if (*cp2++ != 'r' || !isdigit(*cp2)) goto std;
218 regnum = *cp2++ - '0';
219 if (isdigit(*cp2))
220 {
221 if (cp2[1] != ']') goto std;
222 regnum *= 10; regnum += *cp2 - '0';
223 }
224 if (regnum != shto) goto std;
225 if (shfrom >= 0) /* ashl $N,r*,r0 */
226 {
227 delnode(p);
228 if (shfrom != shto)
229 {
230 uses[shto] = NULL; splitrand(pf);
231 cp2=regs[RT1]; while (*cp2++!='[');
232 cp1=regfrom; while (*cp2++= *cp1++);
233 newcode(pf);
234 }
235 }
236 else
237 {
238 p->op = MOV; splitrand(p);
239 strcpy(regs[RT1], regs[RT2]);
240 strcpy(regs[RT2], regs[RT3]);
241 regs[RT3][0] = '\0';
242 p->pop = 0; newcode(p);
243 }
244 switch (shcnt)
245 {
246 case 1: pf->subop = WORD; break;
247 case 2: pf->subop = LONG; break;
248 case 3: pf->subop = QUAD; break;
249 }
250 redunm++; nsaddr++; nchange++;
251 }
252 goto std;
253ashadd:
254 /* at this point, RT2 and RT3 are guaranteed to be simple regs*/
255 if (shcnt == 1 && equstr(regs[RT2], regs[RT3]))
256 {
257 /*
258 ** quickie:
259 ** ashl $1,A,A > addl2 A,A
260 */
261 p->op = ADD; p->subop = U(LONG,OP2); p->pop = 0;
262 strcpy(regs[RT1], regs[RT2]); regs[RT3][0] = '\0';
263 newcode(p); nchange++;
264 }
265 goto std;
266 }
267
268 case EXTV:
269 case EXTZV:
270 {
271 /* bit tests:
272 ** extv A,$1,B,rC \
273 ** tstl rC > jbc A,B,D
274 ** jeql D /
275 **
276 ** also byte- and word-size fields:
277 ** extv $n*8,$8,A,B > cvtbl n+A,B
278 ** extv $n*16,$16,A,B > cvtwl n+A,B
279 ** extzv $n*8,$8,A,B > movzbl n+A,B
280 ** extzv $n*16,$16,A,B > movzwl n+A,B
281 */
282 register struct node *pf; /* forward node */
283 register struct node *pn; /* next node (after pf) */
284 int flen; /* field length */
285
286 splitrand(p);
287 if (regs[RT2][0] != '$') goto std;
288 if ((flen = getnum(&regs[RT2][1])) < 0) goto std;
289 if (flen == 1)
290 {
291 register int extreg; /* reg extracted to */
292
293 extreg = isreg(regs[RT4]);
294 if (extreg < 0 || extreg >= NUSE) goto std;
295 if ((pf = p->forw)->op != TST) goto std;
296 if (uses[extreg] && uses[extreg] != pf) goto std;
297 splitrand(pf);
298 if (extreg != isreg(regs[RT1])) goto std;
299 if ((pn = pf->forw)->op != CBR) goto std;
300 if (pn->subop != JEQ && pn->subop != JNE) goto std;
301 delnode(p); delnode(pf);
302 pn->subop = (pn->subop == JEQ) ? JBC : JBS;
303 for(cp2=p->code; *cp2++!=',';);
304 for(cp1=cp2; *cp1++!=',';);
305 while (*cp1!=',') *cp2++= *cp1++; *cp2='\0';
306 pn->code = p->code; pn->pop = NULL;
307 uses[extreg] = NULL;
308 }
309 else
310 if (flen == 8 || flen == 16)
311 {
312 register int boff; /* bit offset */
313 register int coff; /* chunk (byte or word) offset*/
314
315 if (regs[RT1][0] != '$') goto std;
316 if ((boff = getnum(&regs[RT1][1])) < 0) goto std;
317 coff = boff / flen;
318 if (coff && (isreg(regs[RT3]) >= 0)) goto std;
319 if (boff < 0 || (boff % flen) != 0) goto std;
320 p->op = (p->op == EXTV) ? CVT : MOVZ;
321 p->subop = U((flen == 8 ? BYTE : WORD), LONG);
322 if (coff == 0)
323 strcpy(regs[RT1], regs[RT3]);
324 else
325 sprintf(regs[RT1], "%d%s%s", coff, regs[RT3][0]=='(' ? "":"+",
326 regs[RT3]);
327 strcpy(regs[RT2], regs[RT4]);
328 regs[RT3][0] = '\0'; regs[RT4][0] = '\0';
329 p->pop = 0; newcode(p);
330 }
331 nchange++;
332 goto std;
333 }
334
335 case CMP:
336 {
337 /* comparison to -63 to -1:
338 ** cmpl r0,$-1 > incl r0
339 ** jeql ...
340 **
341 ** cmpl r0,$-63 > addl2 $63,r0
342 ** jeql ...
343 */
344 register int num;
345 register int reg;
346 register struct node *regp = p->back;
347
348 if (p->forw->op != CBR) goto std;
349 if (p->forw->subop != JEQ && p->forw->subop != JNE) goto std;
350 splitrand(p);
351 if (strncmp(regs[RT2], "$-", 2) != 0) goto std;
352 reg = r = isreg(regs[RT1]);
353 if (r < 0) goto std;
354 if (r < NUSE && uses[r] != 0) goto std;
355 if (r >= NUSE && regp->op == MOV && p->subop == regp->subop)
356 {
357 if (*regp->code != 'r') goto std;
358 reg = regp->code[1] - '0';
359 if (isdigit(regp->code[2]) || reg >= NUSE || uses[reg])
360 goto std;
361 }
362 if (r >= NUSE) goto std;
363 if (reg != r)
364 sprintf(regs[RT1], "r%d", reg);
365 if ((num = getnum(&regs[RT2][2])) <= 0 || num > 63) goto std;
366 if (num == 1)
367 {
368 p->op = INC; regs[RT2][0] = '\0';
369 }
370 else
371 {
372 register char *t;
373
374 t=regs[RT1];regs[RT1]=regs[RT2];regs[RT2]=t;
375 p->op = ADD; p->subop = U(p->subop, OP2);
376 for (t = &regs[RT1][2]; t[-1] = *t; t++) ;
377 }
378 p->pop = 0; newcode(p);
379 nchange++;
380 goto std;
381 }
382
383 case JSB:
384 if (equstr(p->code,"mcount")) {uses[0]=p; regs[0][0]= -1;}
385 goto std;
386 case JBR: case JMP:
387 clearuse();
388 if (p->subop==RET || p->subop==RSB) {uses[0]=p; regs[0][0]= -1; break;}
389 if (p->ref==0) goto std; /* jmp (r0) */
390 /* fall through */
391 case CBR:
392 if (p->ref->ref!=0) for (r=NUSE;--r>=0;)
393 if (biti[r] & (int)p->ref->ref) {uses[r]=p; regs[r][0]= -1;}
394 case EROU: case JSW:
395 case TEXT: case DATA: case BSS: case ALIGN: case WGEN: case END: ;
396 }
397 }
398 for (p= &first; p!=0; p=p->forw)
399 if (p->op==LABEL || p->op==DLABEL) p->ref=0; /* erase our tracks */
400}
401
402rmove()
403{
404 register struct node *p, *lastp;
405 register int r;
406 int r1;
407
408 clearreg();
409 for (p=first.forw; p!=0; p = p->forw) {
410 lastp=p;
411 if (debug) {
412 printf("Regs:\n");
413 for (r=0; r<NREG; r++)
414 if (regs[r][0]) {
415 r1=regs[r][0];
416 printf("%d: %d%d %s\n", r, r1&0xF, r1>>4, regs[r]+1);
417 }
418 printf("-\n");
419 }
420 switch (p->op) {
421
422 case CVT:
423 splitrand(p); goto mov;
424
425 case MOV:
426 splitrand(p);
427 if ((r = findrand(regs[RT1],p->subop)) >= 0) {
428 if (r == isreg(regs[RT2]) && p->forw->op!=CBR) {
429 delnode(p); redunm++; break;
430 }
431 }
432mov:
433 repladdr(p);
434 r = isreg(regs[RT1]);
435 r1 = isreg(regs[RT2]);
436 dest(regs[RT2],p->subop);
d1580951
BJ		 437 if (r>=0) {
438 if (r1>=0) savereg(r1, regs[r]+1, p->subop);
439 else if (p->op!=CVT) savereg(r, regs[RT2], p->subop);
440 } else if (r1>=0) savereg(r1, regs[RT1], p->subop);
441 else if (p->op!=CVT) setcon(regs[RT1], regs[RT2], p->subop);
f00d91fc
BJ		 442 break;
443
444/* .rx,.wx */
445 case MFPR:
446 case COM:
447 case NEG:
448/* .rx,.wx or .rx,.rx,.wx */
449 case ADD:
450 case SUB:
451 case BIC:
452 case BIS:
453 case XOR:
454 case MUL:
455 case DIV:
456 case ASH:
457 case MOVZ:
458/* .rx,.rx,.rx,.wx */
459 case EXTV:
460 case EXTZV:
461 case INSV:
462 splitrand(p);
463 repladdr(p);
464 dest(lastrand,p->subop);
465 if (p->op==INSV) ccloc[0]=0;
466 break;
467
468/* .mx or .wx */
469 case CLR:
470 case INC:
471 case DEC:
472 splitrand(p);
473 dest(lastrand,p->subop);
474 if (p->op==CLR)
475 if ((r = isreg(regs[RT1])) >= 0)
476 savereg(r, "$0", p->subop);
477 else
478 setcon("$0", regs[RT1], p->subop);
479 break;
480
481/* .rx */
482 case TST:
483 case PUSH:
484 splitrand(p);
485 lastrand=regs[RT1+1]; /* fool repladdr into doing 1 operand */
486 repladdr(p);
487 if (p->op==TST && equstr(lastrand=regs[RT1], ccloc+1)
488 && ((0xf&(ccloc[0]>>4))==p->subop || equtype(ccloc[0],p->subop))
489 &&!source(lastrand)) {
490 delnode(p); p = p->back; nrtst++; nchange++;
491 }
492 setcc(lastrand,p->subop);
493 break;
494
495/* .rx,.rx,.rx */
496 case PROBER:
497 case PROBEW:
498 case CASE:
499 case MOVC3:
500/* .rx,.rx */
501 case MTPR:
502 case CALLS:
503 case CMP:
504 case BIT:
505 splitrand(p);
506 /* fool repladdr into doing right number of operands */
9ad46604 507 if (p->op==CASE || p->op==PROBER || p->op==PROBEW) lastrand=regs[RT4];
c2a86b7c 508/* else if (p->op==CMPV || p->op==CMPZV) lastrand=regs[RT4+1]; */
9ad46604 509 else if (p->op==MOVC3) lastrand=regs[RT1];
f00d91fc
BJ		 510 else lastrand=regs[RT3];
511 repladdr(p);
512 if (p->op==CALLS || p->op==MOVC3) clearreg();
513 if (p->op==BIT) bitopt(p);
514 ccloc[0]=0; break;
515
516 case CBR:
517 if (p->subop>=JBC) {
518 splitrand(p);
519 if (p->subop<JBCC) lastrand=regs[RT3]; /* 2 operands can be optimized */
520 else lastrand=regs[RT2]; /* .mb destinations lose */
521 repladdr(p);
522 }
523 ccloc[0] = 0;
524 break;
525
526 case JBR:
527 redunbr(p);
528
529/* .wx,.bb */
530 case SOB:
531
532 default:
533 clearreg();
534 }
535 }
536}
537
538char *
539byondrd(p) register struct node *p; {
540/* return pointer to register which is "beyond last read/modify operand" */
541 if (OP2==(p->subop>>4)) return(regs[RT3]);
542 switch (p->op) {
543 case MFPR:
544 case JSB:
545 case PUSHA:
546 case TST: case INC: case DEC: case PUSH: return(regs[RT2]);
547 case MTPR:
548 case BIT: case CMP: case CALLS: return(regs[RT3]);
549 case PROBER: case PROBEW:
550 case CASE: case MOVC3: return(regs[RT4]);
551 }
552 return(lastrand);
553}
554
555struct node *
556bflow(p)
557register struct node *p;
558{
559 register char *cp1,*cp2,**preg; register int r;
560 int flow= -1;
561 struct node *olduse=0;
562 splitrand(p);
563 if (p->op!=PUSH && p->subop && 0<=(r=isreg(lastrand)) && r<NUSE && uses[r]==p->forw) {
564 if (equtype(p->subop,regs[r][0])
565 || ((p->op==CVT || p->op==MOVZ)
566 && 0xf&regs[r][0] && compat(0xf&(p->subop>>4),regs[r][0]))) {
567 register int r2;
568 if (regs[r][1]!=0) {/* send directly to destination */
569 if (p->op==INC || p->op==DEC) {
570 if (p->op==DEC) p->op=SUB; else p->op=ADD;
571 p->subop=(OP2<<4)+(p->subop&0xF); /* use 2 now, convert to 3 later */
572 p->pop=0;
573 cp1=lastrand; cp2=regs[RT2]; while (*cp2++= *cp1++); /* copy reg */
574 cp1=lastrand; *cp1++='$'; *cp1++='1'; *cp1=0;
575 }
576 cp1=regs[r]+1; cp2=lastrand;
577 if (OP2==(p->subop>>4)) {/* use 3 operand form of instruction */
578 p->pop=0;
579 p->subop += (OP3-OP2)<<4; lastrand=cp2=regs[RT3];
580 }
581 while (*cp2++= *cp1++);
582 if (p->op==MOVA && p->forw->op==PUSH) {
583 p->op=PUSHA; *regs[RT2]=0; p->pop=0;
584 } else if (p->op==MOV && p->forw->op==PUSH) {
585 p->op=PUSH ; *regs[RT2]=0; p->pop=0;
586 }
587 delnode(p->forw);
588 if (0<=(r2=isreg(lastrand)) && r2<NUSE) {
589 uses[r2]=uses[r]; uses[r]=0;
590 }
591 redun3(p,0);
592 newcode(p); redunm++; flow=r;
593 } else if (p->op==MOV && p->forw->op!=EXTV && p->forw->op!=EXTZV) {
594 /* superfluous fetch */
595 int nmatch;
033bb901 596 char src[C2_ASIZE];
f00d91fc
BJ		 597 movit:
598 cp2=src; cp1=regs[RT1]; while (*cp2++= *cp1++);
599 splitrand(p->forw);
600 if (p->forw->op != INC && p->forw->op != DEC)
601 lastrand=byondrd(p->forw);
602 nmatch=0;
603 for (preg=regs+RT1;*preg!=lastrand;preg++)
604 if (r==isreg(*preg)) {
605 cp2= *preg; cp1=src; while (*cp2++= *cp1++); ++nmatch;
606 }
607 if (nmatch==1) {
608 if (OP2==(p->forw->subop>>4) && equstr(src,regs[RT2])) {
609 p->forw->pop=0;
610 p->forw->subop += (OP3-OP2)<<4; cp1=regs[RT3];
611 *cp1++='r'; *cp1++=r+'0'; *cp1=0;
612 }
613 delnode(p); p=p->forw;
614 if (0<=(r2=isreg(src)) && r2<NUSE) {
615 uses[r2]=uses[r]; uses[r]=0;
616 }
617 redun3(p,0);
618 newcode(p); redunm++; flow=r;
619 } else splitrand(p);
620 }
621 } else if (p->op==MOV && (p->forw->op==CVT || p->forw->op==MOVZ)
622 && p->forw->subop&0xf /* if base or index, then forget it */
623 && compat(p->subop,p->forw->subop) && !source(cp1=regs[RT1])
624 && !indexa(cp1)) goto movit;
625 }
626 /* adjust 'lastrand' past any 'read' or 'modify' operands. */
627 lastrand=byondrd(p);
628 /* a 'write' clobbers the register. */
629 if (0<=(r=isreg(lastrand)) && r<NUSE
630 || OP2==(p->subop>>4) && 0<=(r=isreg(regs[RT2])) && r<NUSE && uses[r]==0) {
631 /* writing a dead register is useless, but watch side effects */
632 switch (p->op) {
35307d30 633 case ACB:
f00d91fc 634 case AOBLEQ: case AOBLSS: case SOBGTR: case SOBGEQ: break;
35307d30 635 default:
f00d91fc
BJ		 636 if (uses[r]==0) {/* no direct uses, check for use of condition codes */
637 register struct node *q=p;
638 while ((q=nonlab(q->forw))->combop==JBR) q=q->ref; /* cc unused, unchanged */
639 if (q->op!=CBR) {/* ... and destroyed */
640 preg=regs+RT1;
641 while (cp1= *preg++) {
642 if (cp1==lastrand) {redunm++; delnode(p); return(p->forw);}
643 if (source(cp1) || equstr(cp1,lastrand)) break;
644 }
645 }
646 }
647 flow=r;
648 }
649 }
650 if (0<=(r=flow)) {olduse=uses[r]; uses[r]=0; *(short *)(regs[r])=0;}
651 /* these two are here, rather than in bmove(),
652 /* because I decided that it was better to go for 3-address code
653 /* (save time) rather than fancy jbxx (save 1 byte)
654 /* on sequences like bisl2 $64,r0; movl r0,foo
655 */
656 if (p->op==BIC) {p=bicopt(p); splitrand(p); lastrand=byondrd(p);}
657 if (p->op==BIS) {bixprep(p,JBSS); lastrand=byondrd(p);}
658 /* now look for 'read' or 'modify' (read & write) uses */
659 preg=regs+RT1;
660 while (*(cp1= *preg++)) {
661 /* check for r */
662 if (lastrand!=cp1 && 0<=(r=isreg(cp1)) && r<NUSE && uses[r]==0) {
663 uses[r]=p; cp2=regs[r]; *cp2++=p->subop;
d1580951 664 if (p->op==ASH && preg==(regs+RT1+1)) cp2[-1]=BYTE; /* stupid DEC */
f00d91fc
BJ		 665 if (p->op==MOV || p->op==PUSH || p->op==CVT || p->op==MOVZ || p->op==COM || p->op==NEG) {
666 if (p->op==PUSH) cp1="-(sp)";
667 else {
668 cp1=regs[RT2];
669 if (0<=(r=isreg(cp1)) && r<NUSE && uses[r]==0)
670 uses[r]=olduse; /* reincarnation!! */
671 /* as in addl2 r0,r1; movl r1,r0; ret */
672 if (p->op!=MOV) cp1=0;
673 }
674 if (cp1) while (*cp2++= *cp1++);
d1580951
BJ		 675 else *cp2=0;
676 } else *cp2=0;
f00d91fc
BJ		 677 continue;
678 }
679 /* check for (r),(r)+,-(r),[r] */
680 do if (*cp1=='(' || *cp1=='[') {/* get register number */
681 char t;
682 cp2= ++cp1; while (*++cp1!=')' && *cp1!=']'); t= *cp1; *cp1=0;
683 if (0<=(r=isreg(cp2)) && r<NUSE && (uses[r]==0 || uses[r]==p)) {
684 uses[r]=p; regs[r][0]=(*--cp2=='[' ? OPX<<4 : OPB<<4);
685 }
686 *cp1=t;
687 } while (*++cp1);
688 }
689 /* pushax or movax possibility? */
690 cp1=regs[RT1];
691 if (*cp1++=='$' && isstatic(cp1) && natural(regs[RT1])) {
692 if (p->combop==T(MOV,LONG)) {
693 if (regs[RT1][1]=='L' && 0!=(p->labno=getnum(regs[RT1]+2))) {
694 cp1=p->code; while (*cp1++!=','); p->code= --cp1;
695 }
696 p->combop=T(MOVA,LONG); ++p->code; p->pop=0;
697 } else if (p->combop==T(PUSH,LONG)) {
698 p->combop=T(PUSHA,LONG); ++p->code; p->pop=0;
699 } else if ((p->combop&0xFFFF)==T(ADD,U(LONG,OP3))
700 && 0<=(r=isreg(regs[RT2]))) {
701 cp1=cp2=p->code; ++cp1;
702 do *cp2++= *cp1; while (*cp1++!=','); cp2[-1]='[';
703 do *cp2++= *cp1; while (*cp1++!=','); cp2[-1]=']';
704 if (!equstr(regs[RT3],"-(sp)")) p->combop=T(MOVA,BYTE);
705 else {p->combop=T(PUSHA,BYTE); *cp2=0;}
706 if (uses[r]==0) {uses[r]=p; regs[r][0]=OPX<<4;}
707 p->pop=0;
708 }
709 }
710 return(p);
711}
712
713ispow2(n) register long n; {/* -1 -> no; else -> log to base 2 */
714 register int log;
715 if (n==0 || n&(n-1)) return(-1); log=0;
716 for (;;) {n >>= 1; if (n==0) return(log); ++log; if (n== -1) return(log);}
717}
718
719bitopt(p) register struct node *p; {
720 /* change "bitx $<power_of_2>,a" followed by JEQ or JNE
721 /* into JBC or JBS. watch out for I/O registers. (?)
722 /* assumes that 'splitrand' has already been called.
723 */
724 register char *cp1,*cp2; int b;
725 cp1=regs[RT1]; cp2=regs[RT2];
726 if (*cp1++!='$' || !okio(cp2) || p->forw->op!=CBR || p->forw->subop&-2 ||
727 0>(b=ispow2(getnum(cp1))) ||
728 p->subop!=BYTE && (source(cp2) || indexa(cp2))) return;
729 if (b>=bitsize[p->subop]) {/* you dummy! */
730 if (source(cp2)) {/* side effect: auto increment or decrement */
731 p->pop=0;
732 p->op=TST; --cp1; while (*cp1++= *cp2++);
733 regs[RT2][0]=0; newcode(p);
734 } else delnode(p);
735 p = p->forw;
736 if (p->subop==JEQ) {p->combop=JBR; p->pop=0;}
737 else delnode(p);
738 nchange++; nbj++; return;
739 }
740 if (cp1=p->forw->code) {/* destination is not an internal label */
741 cp2=regs[RT3]; while (*cp2++= *cp1++);
742 }
743 if (b==0 && (p->subop==LONG || !indexa(regs[RT2]))) {/* JLB optimization, ala BLISS */
744 cp2=regs[RT1]; cp1=regs[RT2]; while (*cp2++= *cp1++);
745 cp2=regs[RT2]; cp1=regs[RT3]; while (*cp2++= *cp1++);
746 *(regs[RT3])=0; p->forw->subop += JLBC-JBC;
747 p->forw->pop=0;
748 } else {
749 cp1=regs[RT1]+1;
750 if (b>9) *cp1++= b/10 +'0'; *cp1++= b%10 +'0'; *cp1=0; /* $<bit_number> */
751 }
752 nbj++; newcode(p); p->combop = p->forw->combop+((JBC-JEQ)<<8);
753 p->labno = p->forw->labno; delnode(p->forw);
754 p->pop=0;
755}
756
757isfield(n) register long n; {/* -1 -> no; else -> position of low bit */
758 register int pos; register long t;
759 t= ((n-1)|n) +1;
760 if (n!=0 && (0==t || 0==n || 0<=ispow2(t))) {
761 pos=0; while(!(n&1)) {n >>= 1; ++pos;} return(pos);
762 } else return(-1);
763}
764
765bixprep(p,bix) register struct node *p; {
766/* initial setup, single-bit checking for bisopt, bicopt.
767/* return: 0->don't bother any more; 1->worthwhile trying
768*/
769 register char *cp1,*cp2;
770 splitrand(p); cp1=regs[RT1]; cp2=regs[RT2];
771 if (*cp1++!='$' || 0>(pos=isfield(f=getnum(cp1)))
772 || !okio(cp2) || indexa(cp2) || source(cp2) || !okio(lastrand)) return(0);
773 f |= f-1; if (++f==0) siz=32-pos; else siz=ispow2(f)-pos;
774 if (siz==1 && pos>5 && (p->subop>>4)==OP2 && (p->subop&0xF)!=BYTE
775 && pos<bitsize[p->subop&0xF]) {
776 p->ref = insertl(p->forw); p->combop = CBR | (bix<<8);
777 p->pop=0;
778 p->labno = p->ref->labno;
779 if (pos>9) {*cp1++= pos/10 +'0'; pos %= 10;}
780 *cp1++=pos+'0'; *cp1=0; newcode(p); nbj++; return(0);
781 }
782 return(1);
783}
784
785
786struct node *
787bicopt(p) register struct node *p; {
788/* use field operations or MOVZ if possible. done as part of 'bflow'.
789*/
790 register char *cp1,*cp2; int r;
3b60efae 791 char src[C2_ASIZE];
f00d91fc
BJ		 792 if (!bixprep(p,JBCC)) return(p);
793 if (f==0) {/* the BIC isolates low order bits */
794 siz=pos; pos=0;
795 if ((p->subop&0xF)==LONG && *(regs[RT2])!='$') {/* result of EXTZV is long */
796 /* save source of BICL in 'src' */
797 cp1=regs[RT2]; cp2=src; while (*cp2++= *cp1++);
798 if (p->back->op==ASH) {/* try for more */
799 splitrand(p->back); cp1=regs[RT1]; cp2=regs[RT3];
800 if (*cp1++=='$' && *(regs[RT2])!='$' && !indexa(regs[RT2])
801 && 0>(f=getnum(cp1)) && equstr(src,cp2)
802 && 0<=(r=isreg(cp2)) && r<NUSE) {/* a good ASH */
803 pos -= f; cp1=regs[RT2]; cp2=src; while (*cp2++= *cp1++);
804 delnode(p->back);
805 }
806 }
807 if (p->back->op==CVT || p->back->op==MOVZ) {/* greedy, aren't we? */
808 splitrand(p->back); cp1=regs[RT1]; cp2=regs[RT2];
809 if (equstr(src,cp2) && okio(cp1) && !indexa(cp1)
810 && 0<=(r=isreg(cp2)) && r<NUSE
811 && bitsize[p->back->subop&0xF]>=(pos+siz)
812 && bitsize[p->back->subop>>4]>=(pos+siz)) {/* good CVT */
813 cp1=regs[RT1]; cp2=src; while (*cp2++= *cp1++);
814 delnode(p->back);
815 }
816 }
817 /* 'pos', 'siz' known; source of field is in 'src' */
818 splitrand(p); /* retrieve destination of BICL */
819 if (siz==8 && pos==0) {
820 p->combop = T(MOVZ,U(BYTE,LONG));
821 sprintf(line,"%s,%s",src,lastrand);
822 } else {
823 p->combop = T(EXTZV,LONG);
824 sprintf(line,"$%d,$%d,%s,%s",pos,siz,src,lastrand);
825 }
826 p->pop=0;
827 p->code = copy(line); nfield++; return(p);
828 }/* end EXTZV possibility */
829 }/* end low order bits */
830/* unfortunately, INSV clears the condition codes, thus cannot be used */
831/* else {/* see if BICL2 of positive field should be INSV $0 */
832/* if (p->subop==(LONG | (OP2<<4)) && 6<=(pos+siz)) {
833/* p->combop = INSV;
834/* sprintf(line,"$0,$%d,$%d,%s",pos,siz,lastrand);
835/* p->code = copy(line); nfield++; return(p);
836/* }
837/* }
838*/
839 return(p);
840}
841
842jumpsw()
843{
844 register struct node *p, *p1;
845 register t;
846 int nj;
847
848 t = 0;
849 nj = 0;
850 for (p=first.forw; p!=0; p = p->forw)
851 p->seq = ++t;
852 for (p=first.forw; p!=0; p = p1) {
853 p1 = p->forw;
854 if (p->op == CBR && p1->op==JBR && p->ref && p1->ref
855 && abs(p->seq - p->ref->seq) > abs(p1->seq - p1->ref->seq)) {
856 if (p->ref==p1->ref)
857 continue;
858 p->subop = revbr[p->subop];
859 p->pop=0;
860 t = p1->ref;
861 p1->ref = p->ref;
862 p->ref = t;
863 t = p1->labno;
864 p1->labno = p->labno;
865 p->labno = t;
866#ifdef COPYCODE
867 if (p->labno == 0) {
868 t = p1->code; p1->code = p->code; p->code = t;
869 }
870#endif
871 nrevbr++;
872 nj++;
873 }
874 }
875 return(nj);
876}
877
878addsob()
879{
880 register struct node *p, *p1, *p2, *p3;
881
882 for (p = &first; (p1 = p->forw)!=0; p = p1) {
883 if (p->combop==T(DEC,LONG) && p1->op==CBR) {
3b60efae 884 if (abs(p->seq - p1->ref->seq) > 8) continue;
f00d91fc
BJ		 885 if (p1->subop==JGE || p1->subop==JGT) {
886 if (p1->subop==JGE) p->combop=SOBGEQ; else p->combop=SOBGTR;
887 p->pop=0;
888 p->labno = p1->labno; delnode(p1); nsob++;
889 }
890 } else if (p->combop==T(INC,LONG)) {
891 if (p1->op==LABEL && p1->refc==1 && p1->forw->combop==T(CMP,LONG)
892 && (p2=p1->forw->forw)->combop==T(CBR,JLE)
893 && (p3=p2->ref->back)->combop==JBR && p3->ref==p1
894 && p3->forw->op==LABEL && p3->forw==p2->ref) {
895 /* change INC LAB: CMP to LAB: INC CMP */
896 p->back->forw=p1; p1->back=p->back;
897 p->forw=p1->forw; p1->forw->back=p;
898 p->back=p1; p1->forw=p;
899 p1=p->forw;
900 /* adjust beginning value by 1 */
901 p2=alloc(sizeof first); p2->combop=T(DEC,LONG);
902 p2->pop=0;
903 p2->forw=p3; p2->back=p3->back; p3->back->forw=p2;
904 p3->back=p2; p2->code=p->code; p2->labno=0;
905 }
906 if (p1->combop==T(CMP,LONG) && (p2=p1->forw)->op==CBR) {
907 register char *cp1,*cp2;
908 splitrand(p1); if (!equstr(p->code,regs[RT1])) continue;
3b60efae 909 if (abs(p->seq - p2->ref->seq)>8) {/* outside byte displ range */
f00d91fc
BJ		 910 if (p2->subop!=JLE) continue;
911 p->combop=T(ACB,LONG);
912 cp2=regs[RT1]; cp1=regs[RT2]; while (*cp2++= *cp1++); /* limit */
913 cp2=regs[RT2]; cp1="$1"; while (*cp2++= *cp1++); /* increment */
914 cp2=regs[RT3]; cp1=p->code; while (*cp2++= *cp1++); /* index */
915 p->pop=0; newcode(p);
916 p->labno = p2->labno; delnode(p2); delnode(p1); nsob++;
917 } else if (p2->subop==JLE || p2->subop==JLT) {
918 if (p2->subop==JLE) p->combop=AOBLEQ; else p->combop=AOBLSS;
919 cp2=regs[RT1]; cp1=regs[RT2]; while (*cp2++= *cp1++); /* limit */
920 cp2=regs[RT2]; cp1=p->code; while (*cp2++= *cp1++); /* index */
921 p->pop=0; newcode(p);
922 p->labno = p2->labno; delnode(p2); delnode(p1); nsob++;
923 }
924 }
925 }
926 }
927}
928
929abs(x)
930{
931 return(x<0? -x: x);
932}
933
934equop(p1, p2)
935register struct node *p1;
936struct node *p2;
937{
938 register char *cp1, *cp2;
939
940 if (p1->combop != p2->combop)
941 return(0);
942 if (p1->op>0 && p1->op<MOV)
943 return(0);
944 if (p1->op==MOVA && p1->labno!=p2->labno) return(0);
945 cp1 = p1->code;
946 cp2 = p2->code;
947 if (cp1==0 && cp2==0)
948 return(1);
949 if (cp1==0 || cp2==0)
950 return(0);
951 while (*cp1 == *cp2++)
952 if (*cp1++ == 0)
953 return(1);
954 return(0);
955}
956
957delnode(p) register struct node *p; {
958 p->back->forw = p->forw;
959 p->forw->back = p->back;
960}
961
962decref(p)
963register struct node *p;
964{
965 if (p && --p->refc <= 0) {
966 nrlab++;
967 delnode(p);
968 }
969}
970
971struct node *
972nonlab(ap)
973struct node *ap;
974{
975 register struct node *p;
976
977 p = ap;
978 while (p && p->op==LABEL)
979 p = p->forw;
980 return(p);
981}
982
983clearuse() {
984 register struct node **i;
985 for (i=uses+NUSE; i>uses;) *--i=0;
986}
987
988clearreg() {
989 register short **i;
990 for (i=regs+NREG; i>regs;) **--i=0;
991 conloc[0] = 0; ccloc[0] = 0;
992}
993
994savereg(ai, s, type)
995register char *s;
996{
997 register char *p, *sp;
998
999 sp = p = regs[ai];
1000 if (source(s)) /* side effects in addressing */
1001 return;
1002 /* if any indexing, must be parameter or local */
1003 /* indirection (as in "*-4(fp)") is ok, however */
1004 *p++ = type;
1005 while (*p++ = *s)
1006 if (*s=='[' || *s++=='(' && *s!='a' && *s!='f') {*sp = 0; return;}
1007}
1008
1009dest(s,type)
1010register char *s;
1011{
1012 register int i;
1013
1014 source(s); /* handle addressing side effects */
1015 if ((i = isreg(s)) >= 0) {
1016 *(short *)(regs[i]) = 0; /* if register destination, that reg is a goner */
0594fe30
BJ		 1017 switch(type & 0xF){
1018 case DFLOAT: /* clobber two at once */
1019 /*FALLTHROUGH*/
1020 case GFLOAT:
1021 *(short *)(regs[i+1]) = 0;
1022 break;
1023 case HFLOAT: /* clobber four at once */
1024 *(short *)(regs[i+1]) = 0;
1025 *(short *)(regs[i+2]) = 0;
1026 *(short *)(regs[i+3]) = 0;
1027 break;
1028 }
1029 switch((type>>4)&0xF){
1030 case DFLOAT: /* clobber two at once */
1031 /*FALLTHROUGH*/
1032 case GFLOAT:
1033 *(short *)(regs[i+1]) = 0;
1034 break;
1035 case HFLOAT: /* clobber four at once */
1036 *(short *)(regs[i+1]) = 0;
1037 *(short *)(regs[i+2]) = 0;
1038 *(short *)(regs[i+3]) = 0;
1039 break;
1040 }
1041 /*
1042 if (DFLOAT==(type&0xF) || DFLOAT==((type>>4)&0xF))
1043 *(short *)(regs[i+1]) = 0;
1044 */
f00d91fc
BJ		 1045 }
1046 for (i=NREG; --i>=0;)
1047 if (regs[i][1]=='*' && equstr(s, regs[i]+2))
1048 *(short *)(regs[i]) = 0; /* previous indirection through destination is invalid */
1049 while ((i = findrand(s,0)) >= 0) /* previous values of destination are invalid */
1050 *(short *)(regs[i]) = 0;
1051 if (!natural(s)) {/* wild store, everything except constants vanishes */
1052 for (i=NREG; --i>=0;) if (regs[i][1] != '$') *(short *)(regs[i]) = 0;
1053 conloc[0] = 0; ccloc[0] = 0;
1054 } else setcc(s,type); /* natural destinations set condition codes */
1055}
1056
1057splitrand(p) struct node *p; {
1058/* separate operands at commas, set up 'regs' and 'lastrand' */
1059register char *p1, *p2; register char **preg;
1060preg=regs+RT1;
1061if (p1=p->code) while (*p1) {
1062 lastrand=p2= *preg++;
1063 while (*p1) if (','==(*p2++= *p1++)) {--p2; break;}
1064 *p2=0;
1065}
1066while (preg<(regs+RT1+5)) *(*preg++)=0;
1067}
1068
1069compat(have, want) {
1070register int hsrc, hdst;
1071if (0==(want &= 0xF)) return(1); /* anything satisfies a wildcard want */
1072hsrc=have&0xF; if (0==(hdst=((have>>4)&0xF)) || hdst>=OP2) hdst=hsrc;
0594fe30
BJ		 1073if (want>=FFLOAT) return(hdst==want && hsrc==want);
1074 /* FLOAT, DFLOAT not compat: rounding */
1075return(hsrc>=want && hdst>=want && hdst<FFLOAT);
f00d91fc
BJ		 1076}
1077
1078equtype(t1,t2) {return(compat(t1,t2) && compat(t2,t1));}
1079
1080findrand(as, type)
1081char *as;
1082{
1083 register char **i;
1084 for (i = regs+NREG; --i>=regs;) {
1085 if (**i && equstr(*i+1, as) && compat(**i,type))
1086 return(i-regs);
1087 }
1088 return(-1);
1089}
1090
1091isreg(s)
1092register char *s;
1093{
1094 if (*s++!='r' || !isdigit(*s++)) return(-1);
1095 if (*s==0) return(*--s-'0');
1096 if (*(s-1)=='1' && isdigit(*s++) && *s==0) return(10+*--s-'0');
1097 return(-1);
1098}
1099
1100check()
1101{
1102 register struct node *p, *lp;
1103
1104 lp = &first;
1105 for (p=first.forw; p!=0; p = p->forw) {
1106 if (p->back != lp)
1107 abort(-1);
1108 lp = p;
1109 }
1110}
1111
1112source(ap)
1113char *ap;
1114{
1115 register char *p1, *p2;
1116
1117 p1 = ap;
1118 p2 = p1;
1119 if (*p1==0)
1120 return(0);
1121 while (*p2++ && *(p2-1)!='[');
1122 if (*p1=='-' && *(p1+1)=='('
1123 || *p1=='*' && *(p1+1)=='-' && *(p1+2)=='('
1124 || *(p2-2)=='+') {
1125 while (*p1 && *p1++!='r');
1126 if (isdigit(*p1++))
1127 if (isdigit(*p1)) *(short *)(regs[10+*p1-'0'])=0;
1128 else *(short *)(regs[*--p1-'0'])=0;
1129 return(1);
1130 }
1131 return(0);
1132}
1133
1134newcode(p) struct node *p; {
1135 register char *p1,*p2,**preg;
1136 preg=regs+RT1; p2=line;
1137 while (*(p1= *preg++)) {while (*p2++= *p1++); *(p2-1)=',';}
1138 *--p2=0;
1139 p->code=copy(line);
1140}
1141
1142repladdr(p)
1143struct node *p;
1144{
1145 register r;
1146 register char *p1, *p2;
1147 char **preg; int nrepl;
1148
1149 preg=regs+RT1; nrepl=0;
1150 while (lastrand!=(p1= *preg++))
1151 if (!source(p1) && 0<=(r=findrand(p1,p->subop))) {
1152 *p1++='r'; if (r>9) {*p1++='1'; r -= 10;} *p1++=r+'0'; *p1=0;
1153 nrepl++; nsaddr++;
1154 }
1155 if (nrepl) newcode(p);
1156}
1157
1158/* movedat()
1159/* {
1160/* register struct node *p1, *p2;
1161/* struct node *p3;
1162/* register seg;
1163/* struct node data;
1164/* struct node *datp;
1165/*
1166/* if (first.forw == 0)
1167/* return;
1168/* datp = &data;
1169/* for (p1 = first.forw; p1!=0; p1 = p1->forw) {
1170/* if (p1->op == DATA) {
1171/* p2 = p1->forw;
1172/* while (p2 && p2->op!=TEXT)
1173/* p2 = p2->forw;
1174/* if (p2==0)
1175/* break;
1176/* p3 = p1->back;
1177/* p1->back->forw = p2->forw;
1178/* p2->forw->back = p3;
1179/* p2->forw = 0;
1180/* datp->forw = p1;
1181/* p1->back = datp;
1182/* p1 = p3;
1183/* datp = p2;
1184/* }
1185/* }
1186/* if (data.forw) {
1187/* datp->forw = first.forw;
1188/* first.forw->back = datp;
1189/* data.forw->back = &first;
1190/* first.forw = data.forw;
1191/* }
1192/* seg = -1;
1193/* for (p1 = first.forw; p1!=0; p1 = p1->forw) {
1194/* if (p1->op==TEXT||p1->op==DATA||p1->op==BSS) {
1195/* if (p1->op == seg || p1->forw&&p1->forw->op==seg) {
1196/* p1->back->forw = p1->forw;
1197/* p1->forw->back = p1->back;
1198/* p1 = p1->back;
1199/* continue;
1200/* }
1201/* seg = p1->op;
1202/* }
1203/* }
1204/* }
1205*/
1206
1207redunbr(p)
1208register struct node *p;
1209{
1210 register struct node *p1;
1211 register char *ap1;
1212 char *ap2;
1213
1214 if ((p1 = p->ref) == 0)
1215 return;
1216 p1 = nonlab(p1);
1217 if (p1->op==TST) {
1218 splitrand(p1);
1219 savereg(RT2, "$0", p1->subop);
1220 } else if (p1->op==CMP)
1221 splitrand(p1);
1222 else
1223 return;
1224 if (p1->forw->op==CBR) {
1225 ap1 = findcon(RT1, p1->subop);
1226 ap2 = findcon(RT2, p1->subop);
1227 p1 = p1->forw;
1228 if (compare(p1->subop, ap1, ap2)) {
1229 nredunj++;
1230 nchange++;
1231 decref(p->ref);
1232 p->ref = p1->ref;
1233 p->labno = p1->labno;
1234#ifdef COPYCODE
1235 if (p->labno == 0)
1236 p->code = p1->code;
1237 if (p->ref)
1238#endif
1239 p->ref->refc++;
1240 }
1241 } else if (p1->op==TST && equstr(regs[RT1],ccloc+1) &&
1242 equtype(ccloc[0],p1->subop)) {
1243 p1=insertl(p1->forw); decref(p->ref); p->ref=p1;
1244 nrtst++; nchange++;
1245 }
1246}
1247
1248char *
1249findcon(i, type)
1250{
1251 register char *p;
1252 register r;
1253
1254 p = regs[i];
1255 if (*p=='$')
1256 return(p);
1257 if ((r = isreg(p)) >= 0 && compat(regs[r][0],type))
1258 return(regs[r]+1);
1259 if (equstr(p, conloc))
1260 return(conval+1);
1261 return(p);
1262}
1263
1264compare(op, acp1, acp2)
1265char *acp1, *acp2;
1266{
1267 register char *cp1, *cp2;
1268 register n1;
1269 int n2; int sign;
1270
1271 cp1 = acp1;
1272 cp2 = acp2;
1273 if (*cp1++ != '$' || *cp2++ != '$')
1274 return(0);
1275 n1 = 0; sign=1; if (*cp2=='-') {++cp2; sign= -1;}
1276 while (isdigit(*cp2)) {n1 *= 10; n1 += (*cp2++ - '0')*sign;}
1277 n2 = n1;
1278 n1 = 0; sign=1; if (*cp1=='-') {++cp1; sign= -1;}
1279 while (isdigit(*cp1)) {n1 *= 10; n1 += (*cp1++ - '0')*sign;}
1280 if (*cp1=='+')
1281 cp1++;
1282 if (*cp2=='+')
1283 cp2++;
1284 do {
1285 if (*cp1++ != *cp2)
1286 return(0);
1287 } while (*cp2++);
1288 cp1 = n1;
1289 cp2 = n2;
1290 switch(op) {
1291
1292 case JEQ:
1293 return(cp1 == cp2);
1294 case JNE:
1295 return(cp1 != cp2);
1296 case JLE:
1297 return(((int)cp1) <= ((int)cp2));
1298 case JGE:
1299 return(((int)cp1) >= ((int)cp2));
1300 case JLT:
1301 return(((int)cp1) < ((int)cp2));
1302 case JGT:
1303 return(((int)cp1) > ((int)cp2));
1304 case JLO:
1305 return(cp1 < cp2);
1306 case JHI:
1307 return(cp1 > cp2);
1308 case JLOS:
1309 return(cp1 <= cp2);
1310 case JHIS:
1311 return(cp1 >= cp2);
1312 }
1313 return(0);
1314}
1315
1316setcon(cv, cl, type)
1317register char *cv, *cl;
1318{
1319 register char *p;
1320
1321 if (*cv != '$')
1322 return;
1323 if (!natural(cl))
1324 return;
1325 p = conloc;
1326 while (*p++ = *cl++);
1327 p = conval;
1328 *p++ = type;
1329 while (*p++ = *cv++);
1330}
1331
1332equstr(p1, p2)
1333register char *p1, *p2;
1334{
1335 do {
1336 if (*p1++ != *p2)
1337 return(0);
1338 } while (*p2++);
1339 return(1);
1340}
1341
1342setcc(ap,type)
1343char *ap;
1344{
1345 register char *p, *p1;
1346
1347 p = ap;
1348 if (!natural(p)) {
1349 ccloc[0] = 0;
1350 return;
1351 }
1352 p1 = ccloc;
1353 *p1++ = type;
1354 while (*p1++ = *p++);
1355}
1356
1357okio(p) register char *p; {/* 0->probable I/O space address; 1->not */
1358 if (ioflag && (!natural(p) || 0>getnum(p))) return(0);
1359 return(1);
1360}
1361
1362indexa(p) register char *p; {/* 1-> uses [r] addressing mode; 0->doesn't */
1363 while (*p) if (*p++=='[') return(1);
1364 return(0);
1365}
1366
1367natural(p)
1368register char *p;
1369{/* 1->simple local, parameter, global, or register; 0->otherwise */
1370 if (*p=='*' || *p=='(' || *p=='-'&&*(p+1)=='(' || *p=='$'&&getnum(p+1))
1371 return(0);
1372 while (*p++);
1373 p--;
1374 if (*--p=='+' || *p==']' || *p==')' && *(p-2)!='a' && *(p-2)!='f')
1375 return(0);
1376 return(1);
1377}
1378
1379/*
1380** Tell if an argument is most likely static.
1381*/
1382
1383isstatic(cp)
1384register char *cp;
1385{
1386 if (*cp == '_' || *cp == 'L' || (*cp++ == 'v' && *cp == '.'))
1387 return (1);
1388 return (0);
1389}
Continuous source code history from original PDP-7 UNIX to FreeBSD 2, the first fully unencumbered FreeBSD release.