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date and time created 88/12/12 20:26:19 by kfall
[unix-history] / usr / src / old / pcc / c2.vax / c21.c
CommitLineData
41feb04a 1#ifndef lint
95fab880 2static char sccsid[] = "@(#)c21.c 4.24 %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 */
a2897263 22 32, /* 4 FFLOAT */
a24e0abe
RH		 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);
95fab880 237 p = pf;
f00d91fc
BJ		 238 if (shfrom != shto)
239 {
95fab880 240 uses[shto] = NULL; splitrand(p);
f00d91fc
BJ		 241 cp2=regs[RT1]; while (*cp2++!='[');
242 cp1=regfrom; while (*cp2++= *cp1++);
41feb04a
RC		 243 *--cp2 = ']';
244 *++cp2 = '\0';
95fab880
DS		 245 newcode(p);
246 }
247 if (p->op == MOVA)
248 {
249 int movato;
250
251 splitrand(p);
252 if ((movato = isreg(regs[RT2])) >= 0
253 && movato < NUSE)
254 /*
255 * this register is dead;
256 * resurrect it temporarily
257 */
258 uses[movato] = p;
f00d91fc
BJ		 259 }
260 }
261 else
262 {
263 p->op = MOV; splitrand(p);
264 strcpy(regs[RT1], regs[RT2]);
265 strcpy(regs[RT2], regs[RT3]);
266 regs[RT3][0] = '\0';
267 p->pop = 0; newcode(p);
268 }
269 switch (shcnt)
270 {
271 case 1: pf->subop = WORD; break;
272 case 2: pf->subop = LONG; break;
273 case 3: pf->subop = QUAD; break;
274 }
95fab880 275 pf->pop = 0;
f00d91fc 276 redunm++; nsaddr++; nchange++;
725aa107 277 goto std;
f00d91fc 278 }
f00d91fc
BJ		 279ashadd:
280 /* at this point, RT2 and RT3 are guaranteed to be simple regs*/
281 if (shcnt == 1 && equstr(regs[RT2], regs[RT3]))
282 {
283 /*
284 ** quickie:
285 ** ashl $1,A,A > addl2 A,A
286 */
287 p->op = ADD; p->subop = U(LONG,OP2); p->pop = 0;
288 strcpy(regs[RT1], regs[RT2]); regs[RT3][0] = '\0';
289 newcode(p); nchange++;
290 }
291 goto std;
292 }
293
294 case EXTV:
295 case EXTZV:
296 {
297 /* bit tests:
298 ** extv A,$1,B,rC \
299 ** tstl rC > jbc A,B,D
300 ** jeql D /
301 **
302 ** also byte- and word-size fields:
303 ** extv $n*8,$8,A,B > cvtbl n+A,B
49c27f9c 304 ** extv $n*16,$16,A,B > cvtwl 2n+A,B
f00d91fc 305 ** extzv $n*8,$8,A,B > movzbl n+A,B
49c27f9c 306 ** extzv $n*16,$16,A,B > movzwl 2n+A,B
f00d91fc
BJ		 307 */
308 register struct node *pf; /* forward node */
309 register struct node *pn; /* next node (after pf) */
310 int flen; /* field length */
311
312 splitrand(p);
313 if (regs[RT2][0] != '$') goto std;
314 if ((flen = getnum(&regs[RT2][1])) < 0) goto std;
315 if (flen == 1)
316 {
317 register int extreg; /* reg extracted to */
318
319 extreg = isreg(regs[RT4]);
320 if (extreg < 0 || extreg >= NUSE) goto std;
321 if ((pf = p->forw)->op != TST) goto std;
322 if (uses[extreg] && uses[extreg] != pf) goto std;
323 splitrand(pf);
324 if (extreg != isreg(regs[RT1])) goto std;
325 if ((pn = pf->forw)->op != CBR) goto std;
326 if (pn->subop != JEQ && pn->subop != JNE) goto std;
327 delnode(p); delnode(pf);
328 pn->subop = (pn->subop == JEQ) ? JBC : JBS;
329 for(cp2=p->code; *cp2++!=',';);
330 for(cp1=cp2; *cp1++!=',';);
331 while (*cp1!=',') *cp2++= *cp1++; *cp2='\0';
332 pn->code = p->code; pn->pop = NULL;
333 uses[extreg] = NULL;
95fab880
DS		 334 p = pn;
335 break;
f00d91fc
BJ		 336 }
337 else
338 if (flen == 8 || flen == 16)
339 {
340 register int boff; /* bit offset */
341 register int coff; /* chunk (byte or word) offset*/
342
343 if (regs[RT1][0] != '$') goto std;
344 if ((boff = getnum(&regs[RT1][1])) < 0) goto std;
345 coff = boff / flen;
346 if (coff && (isreg(regs[RT3]) >= 0)) goto std;
347 if (boff < 0 || (boff % flen) != 0) goto std;
348 p->op = (p->op == EXTV) ? CVT : MOVZ;
349 p->subop = U((flen == 8 ? BYTE : WORD), LONG);
350 if (coff == 0)
351 strcpy(regs[RT1], regs[RT3]);
352 else
49c27f9c
RC		 353 sprintf(regs[RT1], "%d%s%s",
354 (flen == 8 ? coff : 2*coff),
355 (regs[RT3][0] == '(' ? "" : "+"),
f00d91fc
BJ		 356 regs[RT3]);
357 strcpy(regs[RT2], regs[RT4]);
358 regs[RT3][0] = '\0'; regs[RT4][0] = '\0';
359 p->pop = 0; newcode(p);
360 }
361 nchange++;
362 goto std;
363 }
364
365 case CMP:
366 {
367 /* comparison to -63 to -1:
368 ** cmpl r0,$-1 > incl r0
369 ** jeql ...
370 **
371 ** cmpl r0,$-63 > addl2 $63,r0
372 ** jeql ...
373 */
374 register int num;
375 register int reg;
376 register struct node *regp = p->back;
377
378 if (p->forw->op != CBR) goto std;
379 if (p->forw->subop != JEQ && p->forw->subop != JNE) goto std;
380 splitrand(p);
381 if (strncmp(regs[RT2], "$-", 2) != 0) goto std;
382 reg = r = isreg(regs[RT1]);
383 if (r < 0) goto std;
384 if (r < NUSE && uses[r] != 0) goto std;
385 if (r >= NUSE && regp->op == MOV && p->subop == regp->subop)
386 {
387 if (*regp->code != 'r') goto std;
388 reg = regp->code[1] - '0';
389 if (isdigit(regp->code[2]) || reg >= NUSE || uses[reg])
390 goto std;
391 }
392 if (r >= NUSE) goto std;
393 if (reg != r)
394 sprintf(regs[RT1], "r%d", reg);
395 if ((num = getnum(&regs[RT2][2])) <= 0 || num > 63) goto std;
396 if (num == 1)
397 {
398 p->op = INC; regs[RT2][0] = '\0';
399 }
400 else
401 {
402 register char *t;
403
404 t=regs[RT1];regs[RT1]=regs[RT2];regs[RT2]=t;
405 p->op = ADD; p->subop = U(p->subop, OP2);
406 for (t = &regs[RT1][2]; t[-1] = *t; t++) ;
407 }
408 p->pop = 0; newcode(p);
409 nchange++;
410 goto std;
411 }
412
413 case JSB:
414 if (equstr(p->code,"mcount")) {uses[0]=p; regs[0][0]= -1;}
415 goto std;
416 case JBR: case JMP:
417 clearuse();
418 if (p->subop==RET || p->subop==RSB) {uses[0]=p; regs[0][0]= -1; break;}
419 if (p->ref==0) goto std; /* jmp (r0) */
420 /* fall through */
421 case CBR:
422 if (p->ref->ref!=0) for (r=NUSE;--r>=0;)
423 if (biti[r] & (int)p->ref->ref) {uses[r]=p; regs[r][0]= -1;}
424 case EROU: case JSW:
425 case TEXT: case DATA: case BSS: case ALIGN: case WGEN: case END: ;
426 }
427 }
428 for (p= &first; p!=0; p=p->forw)
429 if (p->op==LABEL || p->op==DLABEL) p->ref=0; /* erase our tracks */
430}
431
432rmove()
433{
41feb04a 434 register struct node *p;
f00d91fc
BJ		 435 register int r;
436 int r1;
437
438 clearreg();
439 for (p=first.forw; p!=0; p = p->forw) {
f00d91fc 440 if (debug) {
6b028d93
RC		 441 if (*conloc) {
442 r1=conval[0];
443 printf("Con %s = %d%d %s\n", conloc, r1&0xF, r1>>4, conval+1);
444 }
f00d91fc
BJ		 445 printf("Regs:\n");
446 for (r=0; r<NREG; r++)
447 if (regs[r][0]) {
448 r1=regs[r][0];
449 printf("%d: %d%d %s\n", r, r1&0xF, r1>>4, regs[r]+1);
450 }
451 printf("-\n");
452 }
453 switch (p->op) {
454
455 case CVT:
456 splitrand(p); goto mov;
457
458 case MOV:
459 splitrand(p);
460 if ((r = findrand(regs[RT1],p->subop)) >= 0) {
461 if (r == isreg(regs[RT2]) && p->forw->op!=CBR) {
462 delnode(p); redunm++; break;
463 }
464 }
465mov:
466 repladdr(p);
467 r = isreg(regs[RT1]);
468 r1 = isreg(regs[RT2]);
469 dest(regs[RT2],p->subop);
d1580951
BJ		 470 if (r>=0) {
471 if (r1>=0) savereg(r1, regs[r]+1, p->subop);
472 else if (p->op!=CVT) savereg(r, regs[RT2], p->subop);
473 } else if (r1>=0) savereg(r1, regs[RT1], p->subop);
474 else if (p->op!=CVT) setcon(regs[RT1], regs[RT2], p->subop);
f00d91fc
BJ		 475 break;
476
477/* .rx,.wx */
478 case MFPR:
479 case COM:
480 case NEG:
481/* .rx,.wx or .rx,.rx,.wx */
482 case ADD:
483 case SUB:
484 case BIC:
485 case BIS:
486 case XOR:
487 case MUL:
488 case DIV:
489 case ASH:
490 case MOVZ:
491/* .rx,.rx,.rx,.wx */
492 case EXTV:
493 case EXTZV:
494 case INSV:
495 splitrand(p);
496 repladdr(p);
497 dest(lastrand,p->subop);
498 if (p->op==INSV) ccloc[0]=0;
499 break;
500
501/* .mx or .wx */
502 case CLR:
503 case INC:
504 case DEC:
505 splitrand(p);
506 dest(lastrand,p->subop);
507 if (p->op==CLR)
508 if ((r = isreg(regs[RT1])) >= 0)
509 savereg(r, "$0", p->subop);
510 else
511 setcon("$0", regs[RT1], p->subop);
512 break;
513
514/* .rx */
515 case TST:
516 case PUSH:
517 splitrand(p);
518 lastrand=regs[RT1+1]; /* fool repladdr into doing 1 operand */
519 repladdr(p);
520 if (p->op==TST && equstr(lastrand=regs[RT1], ccloc+1)
521 && ((0xf&(ccloc[0]>>4))==p->subop || equtype(ccloc[0],p->subop))
522 &&!source(lastrand)) {
523 delnode(p); p = p->back; nrtst++; nchange++;
524 }
525 setcc(lastrand,p->subop);
526 break;
527
528/* .rx,.rx,.rx */
529 case PROBER:
530 case PROBEW:
531 case CASE:
532 case MOVC3:
533/* .rx,.rx */
534 case MTPR:
535 case CALLS:
536 case CMP:
537 case BIT:
538 splitrand(p);
539 /* fool repladdr into doing right number of operands */
9ad46604 540 if (p->op==CASE || p->op==PROBER || p->op==PROBEW) lastrand=regs[RT4];
c2a86b7c 541/* else if (p->op==CMPV || p->op==CMPZV) lastrand=regs[RT4+1]; */
9ad46604 542 else if (p->op==MOVC3) lastrand=regs[RT1];
f00d91fc
BJ		 543 else lastrand=regs[RT3];
544 repladdr(p);
545 if (p->op==CALLS || p->op==MOVC3) clearreg();
546 if (p->op==BIT) bitopt(p);
547 ccloc[0]=0; break;
548
549 case CBR:
550 if (p->subop>=JBC) {
551 splitrand(p);
552 if (p->subop<JBCC) lastrand=regs[RT3]; /* 2 operands can be optimized */
553 else lastrand=regs[RT2]; /* .mb destinations lose */
554 repladdr(p);
555 }
556 ccloc[0] = 0;
557 break;
558
559 case JBR:
560 redunbr(p);
561
562/* .wx,.bb */
563 case SOB:
564
565 default:
566 clearreg();
567 }
568 }
569}
570
571char *
572byondrd(p) register struct node *p; {
573/* return pointer to register which is "beyond last read/modify operand" */
574 if (OP2==(p->subop>>4)) return(regs[RT3]);
575 switch (p->op) {
576 case MFPR:
577 case JSB:
578 case PUSHA:
579 case TST: case INC: case DEC: case PUSH: return(regs[RT2]);
580 case MTPR:
581 case BIT: case CMP: case CALLS: return(regs[RT3]);
582 case PROBER: case PROBEW:
583 case CASE: case MOVC3: return(regs[RT4]);
584 }
585 return(lastrand);
586}
587
588struct node *
589bflow(p)
590register struct node *p;
591{
592 register char *cp1,*cp2,**preg; register int r;
593 int flow= -1;
594 struct node *olduse=0;
595 splitrand(p);
596 if (p->op!=PUSH && p->subop && 0<=(r=isreg(lastrand)) && r<NUSE && uses[r]==p->forw) {
a2897263
DS		 597 if ((p->op==CVT || p->op==MOVZ)
598 && (p->forw->op==CVT || p->forw->op==MOVZ)
599 && p->forw->subop&0xf
91c626f2 600 && equtype(p->subop,p->forw->subop)
a2897263
DS		 601 && !source(cp1=regs[RT1])
602 && !indexa(cp1)) goto movit;
f00d91fc
BJ		 603 if (equtype(p->subop,regs[r][0])
604 || ((p->op==CVT || p->op==MOVZ)
605 && 0xf&regs[r][0] && compat(0xf&(p->subop>>4),regs[r][0]))) {
606 register int r2;
607 if (regs[r][1]!=0) {/* send directly to destination */
608 if (p->op==INC || p->op==DEC) {
609 if (p->op==DEC) p->op=SUB; else p->op=ADD;
610 p->subop=(OP2<<4)+(p->subop&0xF); /* use 2 now, convert to 3 later */
611 p->pop=0;
612 cp1=lastrand; cp2=regs[RT2]; while (*cp2++= *cp1++); /* copy reg */
613 cp1=lastrand; *cp1++='$'; *cp1++='1'; *cp1=0;
614 }
615 cp1=regs[r]+1; cp2=lastrand;
616 if (OP2==(p->subop>>4)) {/* use 3 operand form of instruction */
617 p->pop=0;
618 p->subop += (OP3-OP2)<<4; lastrand=cp2=regs[RT3];
619 }
620 while (*cp2++= *cp1++);
621 if (p->op==MOVA && p->forw->op==PUSH) {
622 p->op=PUSHA; *regs[RT2]=0; p->pop=0;
623 } else if (p->op==MOV && p->forw->op==PUSH) {
624 p->op=PUSH ; *regs[RT2]=0; p->pop=0;
625 }
626 delnode(p->forw);
627 if (0<=(r2=isreg(lastrand)) && r2<NUSE) {
628 uses[r2]=uses[r]; uses[r]=0;
629 }
41feb04a 630 (void) redun3(p,0);
f00d91fc
BJ		 631 newcode(p); redunm++; flow=r;
632 } else if (p->op==MOV && p->forw->op!=EXTV && p->forw->op!=EXTZV) {
633 /* superfluous fetch */
634 int nmatch;
033bb901 635 char src[C2_ASIZE];
f00d91fc
BJ		 636 movit:
637 cp2=src; cp1=regs[RT1]; while (*cp2++= *cp1++);
638 splitrand(p->forw);
639 if (p->forw->op != INC && p->forw->op != DEC)
640 lastrand=byondrd(p->forw);
641 nmatch=0;
642 for (preg=regs+RT1;*preg!=lastrand;preg++)
643 if (r==isreg(*preg)) {
644 cp2= *preg; cp1=src; while (*cp2++= *cp1++); ++nmatch;
645 }
646 if (nmatch==1) {
647 if (OP2==(p->forw->subop>>4) && equstr(src,regs[RT2])) {
648 p->forw->pop=0;
649 p->forw->subop += (OP3-OP2)<<4; cp1=regs[RT3];
650 *cp1++='r'; *cp1++=r+'0'; *cp1=0;
651 }
652 delnode(p); p=p->forw;
653 if (0<=(r2=isreg(src)) && r2<NUSE) {
654 uses[r2]=uses[r]; uses[r]=0;
655 }
41feb04a 656 (void) redun3(p,0);
604a11d8
DS		 657 newcode(p); redunm++;
658 return(p); /* avoid stale uses[] data */
f00d91fc
BJ		 659 } else splitrand(p);
660 }
661 } else if (p->op==MOV && (p->forw->op==CVT || p->forw->op==MOVZ)
662 && p->forw->subop&0xf /* if base or index, then forget it */
663 && compat(p->subop,p->forw->subop) && !source(cp1=regs[RT1])
664 && !indexa(cp1)) goto movit;
665 }
666 /* adjust 'lastrand' past any 'read' or 'modify' operands. */
667 lastrand=byondrd(p);
668 /* a 'write' clobbers the register. */
669 if (0<=(r=isreg(lastrand)) && r<NUSE
670 || OP2==(p->subop>>4) && 0<=(r=isreg(regs[RT2])) && r<NUSE && uses[r]==0) {
671 /* writing a dead register is useless, but watch side effects */
672 switch (p->op) {
35307d30 673 case ACB:
f00d91fc 674 case AOBLEQ: case AOBLSS: case SOBGTR: case SOBGEQ: break;
35307d30 675 default:
f00d91fc
BJ		 676 if (uses[r]==0) {/* no direct uses, check for use of condition codes */
677 register struct node *q=p;
678 while ((q=nonlab(q->forw))->combop==JBR) q=q->ref; /* cc unused, unchanged */
679 if (q->op!=CBR) {/* ... and destroyed */
680 preg=regs+RT1;
681 while (cp1= *preg++) {
682 if (cp1==lastrand) {redunm++; delnode(p); return(p->forw);}
683 if (source(cp1) || equstr(cp1,lastrand)) break;
684 }
685 }
686 }
687 flow=r;
688 }
689 }
41feb04a
RC		 690 if (0<=(r=flow)) {
691 olduse=uses[r];
692 uses[r]=0;
693 regs[r][0]=regs[r][1]=0;
694 }
f00d91fc
BJ		 695 /* these two are here, rather than in bmove(),
696 /* because I decided that it was better to go for 3-address code
697 /* (save time) rather than fancy jbxx (save 1 byte)
698 /* on sequences like bisl2 $64,r0; movl r0,foo
699 */
700 if (p->op==BIC) {p=bicopt(p); splitrand(p); lastrand=byondrd(p);}
41feb04a 701 if (p->op==BIS) {(void) bixprep(p,JBSS); lastrand=byondrd(p);}
f00d91fc
BJ		 702 /* now look for 'read' or 'modify' (read & write) uses */
703 preg=regs+RT1;
704 while (*(cp1= *preg++)) {
705 /* check for r */
706 if (lastrand!=cp1 && 0<=(r=isreg(cp1)) && r<NUSE && uses[r]==0) {
707 uses[r]=p; cp2=regs[r]; *cp2++=p->subop;
d1580951 708 if (p->op==ASH && preg==(regs+RT1+1)) cp2[-1]=BYTE; /* stupid DEC */
f00d91fc
BJ		 709 if (p->op==MOV || p->op==PUSH || p->op==CVT || p->op==MOVZ || p->op==COM || p->op==NEG) {
710 if (p->op==PUSH) cp1="-(sp)";
711 else {
712 cp1=regs[RT2];
713 if (0<=(r=isreg(cp1)) && r<NUSE && uses[r]==0)
714 uses[r]=olduse; /* reincarnation!! */
715 /* as in addl2 r0,r1; movl r1,r0; ret */
716 if (p->op!=MOV) cp1=0;
717 }
718 if (cp1) while (*cp2++= *cp1++);
d1580951
BJ		 719 else *cp2=0;
720 } else *cp2=0;
f00d91fc
BJ		 721 continue;
722 }
723 /* check for (r),(r)+,-(r),[r] */
724 do if (*cp1=='(' || *cp1=='[') {/* get register number */
725 char t;
726 cp2= ++cp1; while (*++cp1!=')' && *cp1!=']'); t= *cp1; *cp1=0;
727 if (0<=(r=isreg(cp2)) && r<NUSE && (uses[r]==0 || uses[r]==p)) {
728 uses[r]=p; regs[r][0]=(*--cp2=='[' ? OPX<<4 : OPB<<4);
729 }
730 *cp1=t;
731 } while (*++cp1);
732 }
733 /* pushax or movax possibility? */
734 cp1=regs[RT1];
735 if (*cp1++=='$' && isstatic(cp1) && natural(regs[RT1])) {
736 if (p->combop==T(MOV,LONG)) {
737 if (regs[RT1][1]=='L' && 0!=(p->labno=getnum(regs[RT1]+2))) {
738 cp1=p->code; while (*cp1++!=','); p->code= --cp1;
739 }
740 p->combop=T(MOVA,LONG); ++p->code; p->pop=0;
741 } else if (p->combop==T(PUSH,LONG)) {
742 p->combop=T(PUSHA,LONG); ++p->code; p->pop=0;
743 } else if ((p->combop&0xFFFF)==T(ADD,U(LONG,OP3))
744 && 0<=(r=isreg(regs[RT2]))) {
745 cp1=cp2=p->code; ++cp1;
746 do *cp2++= *cp1; while (*cp1++!=','); cp2[-1]='[';
747 do *cp2++= *cp1; while (*cp1++!=','); cp2[-1]=']';
748 if (!equstr(regs[RT3],"-(sp)")) p->combop=T(MOVA,BYTE);
749 else {p->combop=T(PUSHA,BYTE); *cp2=0;}
3464f46e
KM		 750 if (r < NUSE && uses[r] == 0) {
751 uses[r]=p;
752 regs[r][0]=OPX<<4;
753 }
f00d91fc
BJ		 754 p->pop=0;
755 }
756 }
757 return(p);
758}
759
760ispow2(n) register long n; {/* -1 -> no; else -> log to base 2 */
761 register int log;
762 if (n==0 || n&(n-1)) return(-1); log=0;
763 for (;;) {n >>= 1; if (n==0) return(log); ++log; if (n== -1) return(log);}
764}
765
766bitopt(p) register struct node *p; {
767 /* change "bitx $<power_of_2>,a" followed by JEQ or JNE
768 /* into JBC or JBS. watch out for I/O registers. (?)
769 /* assumes that 'splitrand' has already been called.
770 */
771 register char *cp1,*cp2; int b;
772 cp1=regs[RT1]; cp2=regs[RT2];
773 if (*cp1++!='$' || !okio(cp2) || p->forw->op!=CBR || p->forw->subop&-2 ||
f69fb1e7
DS		 774 0>(b=ispow2(getnum(cp1)))) return;
775 if (p->subop!=BYTE && !(b==0 && p->subop==LONG) &&
776 (source(cp2) || indexa(cp2))) return;
f00d91fc
BJ		 777 if (b>=bitsize[p->subop]) {/* you dummy! */
778 if (source(cp2)) {/* side effect: auto increment or decrement */
779 p->pop=0;
780 p->op=TST; --cp1; while (*cp1++= *cp2++);
781 regs[RT2][0]=0; newcode(p);
782 } else delnode(p);
783 p = p->forw;
784 if (p->subop==JEQ) {p->combop=JBR; p->pop=0;}
785 else delnode(p);
786 nchange++; nbj++; return;
787 }
788 if (cp1=p->forw->code) {/* destination is not an internal label */
789 cp2=regs[RT3]; while (*cp2++= *cp1++);
790 }
f69fb1e7
DS		 791 if (b==0 && (p->subop==LONG || !(source(regs[RT2]) || indexa(regs[RT2])))) {
792 /* JLB optimization, ala BLISS */
f00d91fc
BJ		 793 cp2=regs[RT1]; cp1=regs[RT2]; while (*cp2++= *cp1++);
794 cp2=regs[RT2]; cp1=regs[RT3]; while (*cp2++= *cp1++);
795 *(regs[RT3])=0; p->forw->subop += JLBC-JBC;
796 p->forw->pop=0;
797 } else {
798 cp1=regs[RT1]+1;
799 if (b>9) *cp1++= b/10 +'0'; *cp1++= b%10 +'0'; *cp1=0; /* $<bit_number> */
800 }
801 nbj++; newcode(p); p->combop = p->forw->combop+((JBC-JEQ)<<8);
802 p->labno = p->forw->labno; delnode(p->forw);
803 p->pop=0;
804}
805
806isfield(n) register long n; {/* -1 -> no; else -> position of low bit */
41feb04a 807 register int p; register long t;
f00d91fc 808 t= ((n-1)|n) +1;
eea63b82 809 if (n!=0 && (0==t || 0<=ispow2(t))) {
41feb04a 810 p=0; while(!(n&1)) {n >>= 1; ++p;} return(p);
f00d91fc
BJ		 811 } else return(-1);
812}
813
814bixprep(p,bix) register struct node *p; {
815/* initial setup, single-bit checking for bisopt, bicopt.
816/* return: 0->don't bother any more; 1->worthwhile trying
817*/
818 register char *cp1,*cp2;
819 splitrand(p); cp1=regs[RT1]; cp2=regs[RT2];
820 if (*cp1++!='$' || 0>(pos=isfield(f=getnum(cp1)))
821 || !okio(cp2) || indexa(cp2) || source(cp2) || !okio(lastrand)) return(0);
822 f |= f-1; if (++f==0) siz=32-pos; else siz=ispow2(f)-pos;
823 if (siz==1 && pos>5 && (p->subop>>4)==OP2 && (p->subop&0xF)!=BYTE
824 && pos<bitsize[p->subop&0xF]) {
825 p->ref = insertl(p->forw); p->combop = CBR | (bix<<8);
826 p->pop=0;
827 p->labno = p->ref->labno;
828 if (pos>9) {*cp1++= pos/10 +'0'; pos %= 10;}
829 *cp1++=pos+'0'; *cp1=0; newcode(p); nbj++; return(0);
830 }
831 return(1);
832}
833
834
835struct node *
836bicopt(p) register struct node *p; {
837/* use field operations or MOVZ if possible. done as part of 'bflow'.
838*/
839 register char *cp1,*cp2; int r;
3b60efae 840 char src[C2_ASIZE];
41feb04a 841 char lhssiz, sop;
f00d91fc
BJ		 842 if (!bixprep(p,JBCC)) return(p);
843 if (f==0) {/* the BIC isolates low order bits */
844 siz=pos; pos=0;
845 if ((p->subop&0xF)==LONG && *(regs[RT2])!='$') {/* result of EXTZV is long */
846 /* save source of BICL in 'src' */
847 cp1=regs[RT2]; cp2=src; while (*cp2++= *cp1++);
848 if (p->back->op==ASH) {/* try for more */
849 splitrand(p->back); cp1=regs[RT1]; cp2=regs[RT3];
850 if (*cp1++=='$' && *(regs[RT2])!='$' && !indexa(regs[RT2])
851 && 0>(f=getnum(cp1)) && equstr(src,cp2)
eea63b82
RC		 852 && 0<=(r=isreg(cp2)) && r<NUSE
853 && siz-f <= 32) { /* a good ASH */
f00d91fc
BJ		 854 pos -= f; cp1=regs[RT2]; cp2=src; while (*cp2++= *cp1++);
855 delnode(p->back);
856 }
857 }
49c27f9c
RC		 858 /*
859 * 'pos', 'siz' known; find out the size of the
860 * left-hand operand of what the bicl will turn into.
861 */
862 if (pos==0 && siz==16)
863 lhssiz = WORD; /* movzwl */
864 else
865 lhssiz = BYTE; /* movzbl or extzvl */
f00d91fc
BJ		 866 if (p->back->op==CVT || p->back->op==MOVZ) {/* greedy, aren't we? */
867 splitrand(p->back); cp1=regs[RT1]; cp2=regs[RT2];
49c27f9c
RC		 868 /*
869 * If indexa(cp1) || autoid(cp1), the fold may
870 * still be OK if the CVT/MOVZ has the same
871 * size operand on its left size as what we
872 * will turn the bicl into.
873 * However, if the CVT is from a float or
874 * double, forget it!
875 */
41feb04a 876 sop = p->back->subop&0xF; /* type of LHS of CVT/MOVZ */
49c27f9c 877 if (equstr(src,cp2) && okio(cp1)
41feb04a
RC		 878 && sop != FFLOAT && sop != DFLOAT
879 && sop != GFLOAT && sop != HFLOAT
880 && ((!indexa(cp1) && !autoid(cp1)) || lhssiz == sop)
f00d91fc 881 && 0<=(r=isreg(cp2)) && r<NUSE
41feb04a 882 && bitsize[sop]>=(pos+siz)
f00d91fc
BJ		 883 && bitsize[p->back->subop>>4]>=(pos+siz)) {/* good CVT */
884 cp1=regs[RT1]; cp2=src; while (*cp2++= *cp1++);
885 delnode(p->back);
886 }
887 }
888 /* 'pos', 'siz' known; source of field is in 'src' */
889 splitrand(p); /* retrieve destination of BICL */
49c27f9c
RC		 890 if ((siz==8 || siz==16) && pos==0) {
891 p->combop = T(MOVZ,U(lhssiz,LONG));
f00d91fc
BJ		 892 sprintf(line,"%s,%s",src,lastrand);
893 } else {
894 p->combop = T(EXTZV,LONG);
895 sprintf(line,"$%d,$%d,%s,%s",pos,siz,src,lastrand);
896 }
897 p->pop=0;
898 p->code = copy(line); nfield++; return(p);
899 }/* end EXTZV possibility */
900 }/* end low order bits */
901/* unfortunately, INSV clears the condition codes, thus cannot be used */
902/* else {/* see if BICL2 of positive field should be INSV $0 */
903/* if (p->subop==(LONG | (OP2<<4)) && 6<=(pos+siz)) {
904/* p->combop = INSV;
905/* sprintf(line,"$0,$%d,$%d,%s",pos,siz,lastrand);
906/* p->code = copy(line); nfield++; return(p);
907/* }
908/* }
909*/
910 return(p);
911}
912
913jumpsw()
914{
915 register struct node *p, *p1;
41feb04a
RC		 916 register struct node *tp;
917 long tl;
918 char *tcp;
919 int ti;
f00d91fc
BJ		 920 int nj;
921
41feb04a 922 ti = 0;
f00d91fc
BJ		 923 nj = 0;
924 for (p=first.forw; p!=0; p = p->forw)
41feb04a 925 p->seq = ++ti;
f00d91fc
BJ		 926 for (p=first.forw; p!=0; p = p1) {
927 p1 = p->forw;
928 if (p->op == CBR && p1->op==JBR && p->ref && p1->ref
929 && abs(p->seq - p->ref->seq) > abs(p1->seq - p1->ref->seq)) {
930 if (p->ref==p1->ref)
931 continue;
932 p->subop = revbr[p->subop];
933 p->pop=0;
41feb04a 934 tp = p1->ref;
f00d91fc 935 p1->ref = p->ref;
41feb04a
RC		 936 p->ref = tp;
937 tl = p1->labno;
f00d91fc 938 p1->labno = p->labno;
41feb04a 939 p->labno = tl;
f00d91fc
BJ		 940#ifdef COPYCODE
941 if (p->labno == 0) {
41feb04a
RC		 942 tcp = p1->code;
943 p1->code = p->code;
944 p->code = tcp;
f00d91fc
BJ		 945 }
946#endif
947 nrevbr++;
948 nj++;
949 }
950 }
951 return(nj);
952}
953
954addsob()
955{
956 register struct node *p, *p1, *p2, *p3;
957
958 for (p = &first; (p1 = p->forw)!=0; p = p1) {
959 if (p->combop==T(DEC,LONG) && p1->op==CBR) {
3b60efae 960 if (abs(p->seq - p1->ref->seq) > 8) continue;
f00d91fc
BJ		 961 if (p1->subop==JGE || p1->subop==JGT) {
962 if (p1->subop==JGE) p->combop=SOBGEQ; else p->combop=SOBGTR;
963 p->pop=0;
964 p->labno = p1->labno; delnode(p1); nsob++;
965 }
966 } else if (p->combop==T(INC,LONG)) {
967 if (p1->op==LABEL && p1->refc==1 && p1->forw->combop==T(CMP,LONG)
968 && (p2=p1->forw->forw)->combop==T(CBR,JLE)
969 && (p3=p2->ref->back)->combop==JBR && p3->ref==p1
970 && p3->forw->op==LABEL && p3->forw==p2->ref) {
971 /* change INC LAB: CMP to LAB: INC CMP */
972 p->back->forw=p1; p1->back=p->back;
973 p->forw=p1->forw; p1->forw->back=p;
974 p->back=p1; p1->forw=p;
975 p1=p->forw;
976 /* adjust beginning value by 1 */
977 p2=alloc(sizeof first); p2->combop=T(DEC,LONG);
978 p2->pop=0;
979 p2->forw=p3; p2->back=p3->back; p3->back->forw=p2;
980 p3->back=p2; p2->code=p->code; p2->labno=0;
981 }
982 if (p1->combop==T(CMP,LONG) && (p2=p1->forw)->op==CBR) {
983 register char *cp1,*cp2;
984 splitrand(p1); if (!equstr(p->code,regs[RT1])) continue;
3b60efae 985 if (abs(p->seq - p2->ref->seq)>8) {/* outside byte displ range */
f00d91fc
BJ		 986 if (p2->subop!=JLE) continue;
987 p->combop=T(ACB,LONG);
988 cp2=regs[RT1]; cp1=regs[RT2]; while (*cp2++= *cp1++); /* limit */
989 cp2=regs[RT2]; cp1="$1"; while (*cp2++= *cp1++); /* increment */
990 cp2=regs[RT3]; cp1=p->code; while (*cp2++= *cp1++); /* index */
991 p->pop=0; newcode(p);
992 p->labno = p2->labno; delnode(p2); delnode(p1); nsob++;
993 } else if (p2->subop==JLE || p2->subop==JLT) {
994 if (p2->subop==JLE) p->combop=AOBLEQ; else p->combop=AOBLSS;
995 cp2=regs[RT1]; cp1=regs[RT2]; while (*cp2++= *cp1++); /* limit */
996 cp2=regs[RT2]; cp1=p->code; while (*cp2++= *cp1++); /* index */
997 p->pop=0; newcode(p);
998 p->labno = p2->labno; delnode(p2); delnode(p1); nsob++;
999 }
1000 }
1001 }
1002 }
1003}
1004
f00d91fc
BJ		 1005equop(p1, p2)
1006register struct node *p1;
1007struct node *p2;
1008{
1009 register char *cp1, *cp2;
1010
1011 if (p1->combop != p2->combop)
1012 return(0);
d5bdb635
DS		 1013 if (p1->combop == 0 && p1->pop != p2->pop)
1014 return(0);
f00d91fc
BJ		 1015 if (p1->op>0 && p1->op<MOV)
1016 return(0);
41feb04a
RC		 1017 switch (p1->combop) {
1018 case EROU: case JSW: case TEXT: case DATA:
1019 case BSS: case ALIGN: case WGEN: case END:
1020 /*
1021 * Consider all pseudo-ops to be unique.
1022 */
1023 return(0);
1024 }
f00d91fc
BJ		 1025 if (p1->op==MOVA && p1->labno!=p2->labno) return(0);
1026 cp1 = p1->code;
1027 cp2 = p2->code;
1028 if (cp1==0 && cp2==0)
1029 return(1);
1030 if (cp1==0 || cp2==0)
1031 return(0);
1032 while (*cp1 == *cp2++)
1033 if (*cp1++ == 0)
1034 return(1);
1035 return(0);
1036}
1037
41feb04a 1038#ifndef delnode
f00d91fc
BJ		 1039delnode(p) register struct node *p; {
1040 p->back->forw = p->forw;
1041 p->forw->back = p->back;
1042}
41feb04a 1043#endif
f00d91fc 1044
41feb04a 1045#ifndef decref
f00d91fc
BJ		 1046decref(p)
1047register struct node *p;
1048{
1049 if (p && --p->refc <= 0) {
1050 nrlab++;
1051 delnode(p);
1052 }
1053}
41feb04a 1054#endif
f00d91fc
BJ		 1055
1056struct node *
1057nonlab(ap)
1058struct node *ap;
1059{
1060 register struct node *p;
1061
1062 p = ap;
1063 while (p && p->op==LABEL)
1064 p = p->forw;
1065 return(p);
1066}
1067
1068clearuse() {
1069 register struct node **i;
1070 for (i=uses+NUSE; i>uses;) *--i=0;
1071}
1072
1073clearreg() {
41feb04a
RC		 1074 register char **i;
1075 for (i=regs; i<regs+NREG; ++i) {
1076 **i = 0;
1077 *(*i+1) = 0;
1078 }
1079 conloc[0] = 0;
1080 ccloc[0] = 0;
f00d91fc
BJ		 1081}
1082
1083savereg(ai, s, type)
1084register char *s;
1085{
1086 register char *p, *sp;
1087
1088 sp = p = regs[ai];
1089 if (source(s)) /* side effects in addressing */
1090 return;
1091 /* if any indexing, must be parameter or local */
1092 /* indirection (as in "*-4(fp)") is ok, however */
1093 *p++ = type;
1094 while (*p++ = *s)
1095 if (*s=='[' || *s++=='(' && *s!='a' && *s!='f') {*sp = 0; return;}
1096}
1097
1098dest(s,type)
1099register char *s;
1100{
1101 register int i;
1102
41feb04a 1103 (void) source(s); /* handle addressing side effects */
6b028d93
RC		 1104 if (!natural(s)) {
1105 /* wild store, everything except constants vanishes */
1106 for (i=NREG; --i>=0;)
41feb04a
RC		 1107 if (regs[i][1] != '$')
1108 regs[i][0] = regs[i][1] = 0;
6b028d93
RC		 1109 conloc[0] = 0; ccloc[0] = 0;
1110 return;
1111 }
f00d91fc 1112 if ((i = isreg(s)) >= 0) {
41feb04a
RC		 1113 /* if register destination, that reg is a goner */
1114 regs[i][0] = regs[i][1] = 0;
0594fe30
BJ		 1115 switch(type & 0xF){
1116 case DFLOAT: /* clobber two at once */
1117 /*FALLTHROUGH*/
1118 case GFLOAT:
41feb04a 1119 regs[i+1][0] = regs[i+1][1] = 0;
0594fe30
BJ		 1120 break;
1121 case HFLOAT: /* clobber four at once */
41feb04a
RC		 1122 regs[i+1][0] = regs[i+1][1] = 0;
1123 regs[i+2][0] = regs[i+2][1] = 0;
1124 regs[i+3][0] = regs[i+3][1] = 0;
0594fe30
BJ		 1125 break;
1126 }
1127 switch((type>>4)&0xF){
1128 case DFLOAT: /* clobber two at once */
1129 /*FALLTHROUGH*/
1130 case GFLOAT:
41feb04a 1131 regs[i+1][0] = regs[i+1][1] = 0;
0594fe30
BJ		 1132 break;
1133 case HFLOAT: /* clobber four at once */
41feb04a
RC		 1134 regs[i+1][0] = regs[i+1][1] = 0;
1135 regs[i+2][0] = regs[i+2][1] = 0;
1136 regs[i+3][0] = regs[i+3][1] = 0;
0594fe30
BJ		 1137 break;
1138 }
f00d91fc
BJ		 1139 }
1140 for (i=NREG; --i>=0;)
1141 if (regs[i][1]=='*' && equstr(s, regs[i]+2))
41feb04a 1142 regs[i][0] = regs[i][1] = 0; /* previous indirection through destination is invalid */
f00d91fc 1143 while ((i = findrand(s,0)) >= 0) /* previous values of destination are invalid */
41feb04a 1144 regs[i][0] = regs[i][1] = 0;
6b028d93
RC		 1145 if (*conloc && equstr(conloc, s))
1146 conloc[0] = 0;
1147 setcc(s, type); /* natural destinations set condition codes */
f00d91fc
BJ		 1148}
1149
f00d91fc 1150/* separate operands at commas, set up 'regs' and 'lastrand' */
6b028d93
RC		 1151splitrand(p) struct node *p; {
1152 register char *p1, *p2;
1153 register char **preg;
1154
1155 preg = regs+RT1;
1156 if (p1 = p->code)
1157 while (*p1) {
1158 lastrand = p2 = *preg++;
1159 while (*p1)
1160 if (',' == (*p2++ = *p1++)) {
1161 --p2;
1162 break;
1163 }
1164 *p2 = 0;
1165 }
1166 while (preg < (regs+RT1+5))
1167 *(*preg++) = 0;
f00d91fc
BJ		 1168}
1169
1170compat(have, want) {
1171register int hsrc, hdst;
1172if (0==(want &= 0xF)) return(1); /* anything satisfies a wildcard want */
cdd0bda3
DS		 1173hsrc=have&0xF;
1174if (0==(hdst=((have>>4)&0xF)) || (hdst>=OP2 && hdst<=OPX)) hdst=hsrc;
0594fe30
BJ		 1175if (want>=FFLOAT) return(hdst==want && hsrc==want);
1176 /* FLOAT, DFLOAT not compat: rounding */
1177return(hsrc>=want && hdst>=want && hdst<FFLOAT);
f00d91fc
BJ		 1178}
1179
1180equtype(t1,t2) {return(compat(t1,t2) && compat(t2,t1));}
1181
1182findrand(as, type)
1183char *as;
1184{
1185 register char **i;
1186 for (i = regs+NREG; --i>=regs;) {
1187 if (**i && equstr(*i+1, as) && compat(**i,type))
1188 return(i-regs);
1189 }
1190 return(-1);
1191}
1192
1193isreg(s)
1194register char *s;
1195{
1196 if (*s++!='r' || !isdigit(*s++)) return(-1);
1197 if (*s==0) return(*--s-'0');
1198 if (*(s-1)=='1' && isdigit(*s++) && *s==0) return(10+*--s-'0');
1199 return(-1);
1200}
1201
1202check()
1203{
1204 register struct node *p, *lp;
1205
1206 lp = &first;
1207 for (p=first.forw; p!=0; p = p->forw) {
41feb04a
RC		 1208 if (p->back != lp) {
1209 fprintf(stderr, "c2: failed internal consistency check -- help!\n");
1210 exit(-1);
1211 }
f00d91fc
BJ		 1212 lp = p;
1213 }
1214}
1215
1216source(ap)
1217char *ap;
1218{
1219 register char *p1, *p2;
1220
1221 p1 = ap;
1222 p2 = p1;
1223 if (*p1==0)
1224 return(0);
1225 while (*p2++ && *(p2-1)!='[');
1226 if (*p1=='-' && *(p1+1)=='('
1227 || *p1=='*' && *(p1+1)=='-' && *(p1+2)=='('
1228 || *(p2-2)=='+') {
1229 while (*p1 && *p1++!='r');
1230 if (isdigit(*p1++))
41feb04a
RC		 1231 if (isdigit(*p1))
1232 regs[10+*p1-'0'][0] = regs[10+*p1-'0'][1] = 0;
1233 else {
1234 --p1;
1235 regs[*p1-'0'][0] = regs[*p1-'0'][1] = 0;
1236 }
f00d91fc
BJ		 1237 return(1);
1238 }
1239 return(0);
1240}
1241
1242newcode(p) struct node *p; {
1243 register char *p1,*p2,**preg;
1244 preg=regs+RT1; p2=line;
1245 while (*(p1= *preg++)) {while (*p2++= *p1++); *(p2-1)=',';}
1246 *--p2=0;
1247 p->code=copy(line);
1248}
1249
1250repladdr(p)
1251struct node *p;
1252{
1253 register r;
41feb04a 1254 register char *p1;
f00d91fc
BJ		 1255 char **preg; int nrepl;
1256
1257 preg=regs+RT1; nrepl=0;
1258 while (lastrand!=(p1= *preg++))
1259 if (!source(p1) && 0<=(r=findrand(p1,p->subop))) {
1260 *p1++='r'; if (r>9) {*p1++='1'; r -= 10;} *p1++=r+'0'; *p1=0;
1261 nrepl++; nsaddr++;
1262 }
1263 if (nrepl) newcode(p);
1264}
1265
1266/* movedat()
1267/* {
1268/* register struct node *p1, *p2;
1269/* struct node *p3;
1270/* register seg;
1271/* struct node data;
1272/* struct node *datp;
1273/*
1274/* if (first.forw == 0)
1275/* return;
1276/* datp = &data;
1277/* for (p1 = first.forw; p1!=0; p1 = p1->forw) {
1278/* if (p1->op == DATA) {
1279/* p2 = p1->forw;
1280/* while (p2 && p2->op!=TEXT)
1281/* p2 = p2->forw;
1282/* if (p2==0)
1283/* break;
1284/* p3 = p1->back;
1285/* p1->back->forw = p2->forw;
1286/* p2->forw->back = p3;
1287/* p2->forw = 0;
1288/* datp->forw = p1;
1289/* p1->back = datp;
1290/* p1 = p3;
1291/* datp = p2;
1292/* }
1293/* }
1294/* if (data.forw) {
1295/* datp->forw = first.forw;
1296/* first.forw->back = datp;
1297/* data.forw->back = &first;
1298/* first.forw = data.forw;
1299/* }
1300/* seg = -1;
1301/* for (p1 = first.forw; p1!=0; p1 = p1->forw) {
1302/* if (p1->op==TEXT||p1->op==DATA||p1->op==BSS) {
1303/* if (p1->op == seg || p1->forw&&p1->forw->op==seg) {
1304/* p1->back->forw = p1->forw;
1305/* p1->forw->back = p1->back;
1306/* p1 = p1->back;
1307/* continue;
1308/* }
1309/* seg = p1->op;
1310/* }
1311/* }
1312/* }
1313*/
1314
1315redunbr(p)
1316register struct node *p;
1317{
1318 register struct node *p1;
1319 register char *ap1;
1320 char *ap2;
1321
1322 if ((p1 = p->ref) == 0)
1323 return;
1324 p1 = nonlab(p1);
1325 if (p1->op==TST) {
1326 splitrand(p1);
1327 savereg(RT2, "$0", p1->subop);
1328 } else if (p1->op==CMP)
1329 splitrand(p1);
1330 else
1331 return;
1332 if (p1->forw->op==CBR) {
1333 ap1 = findcon(RT1, p1->subop);
1334 ap2 = findcon(RT2, p1->subop);
1335 p1 = p1->forw;
1336 if (compare(p1->subop, ap1, ap2)) {
1337 nredunj++;
1338 nchange++;
1339 decref(p->ref);
1340 p->ref = p1->ref;
1341 p->labno = p1->labno;
1342#ifdef COPYCODE
1343 if (p->labno == 0)
1344 p->code = p1->code;
f00d91fc 1345#endif
6b028d93 1346 if (p->ref)
f00d91fc
BJ		 1347 p->ref->refc++;
1348 }
1349 } else if (p1->op==TST && equstr(regs[RT1],ccloc+1) &&
1350 equtype(ccloc[0],p1->subop)) {
95fab880
DS		 1351 p1=insertl(p1->forw);
1352 decref(p->ref);
1353 p->ref=p1;
1354 p->labno=p1->labno;
f00d91fc
BJ		 1355 nrtst++; nchange++;
1356 }
1357}
1358
1359char *
1360findcon(i, type)
1361{
1362 register char *p;
1363 register r;
1364
1365 p = regs[i];
1366 if (*p=='$')
1367 return(p);
1368 if ((r = isreg(p)) >= 0 && compat(regs[r][0],type))
1369 return(regs[r]+1);
1370 if (equstr(p, conloc))
1371 return(conval+1);
1372 return(p);
1373}
1374
41feb04a 1375compare(opc, acp1, acp2)
f00d91fc
BJ		 1376char *acp1, *acp2;
1377{
1378 register char *cp1, *cp2;
1379 register n1;
1380 int n2; int sign;
1381
1382 cp1 = acp1;
1383 cp2 = acp2;
1384 if (*cp1++ != '$' || *cp2++ != '$')
1385 return(0);
1386 n1 = 0; sign=1; if (*cp2=='-') {++cp2; sign= -1;}
1387 while (isdigit(*cp2)) {n1 *= 10; n1 += (*cp2++ - '0')*sign;}
1388 n2 = n1;
1389 n1 = 0; sign=1; if (*cp1=='-') {++cp1; sign= -1;}
1390 while (isdigit(*cp1)) {n1 *= 10; n1 += (*cp1++ - '0')*sign;}
1391 if (*cp1=='+')
1392 cp1++;
1393 if (*cp2=='+')
1394 cp2++;
1395 do {
1396 if (*cp1++ != *cp2)
1397 return(0);
1398 } while (*cp2++);
41feb04a 1399 switch(opc) {
f00d91fc
BJ		 1400
1401 case JEQ:
41feb04a 1402 return(n1 == n2);
f00d91fc 1403 case JNE:
41feb04a 1404 return(n1 != n2);
f00d91fc 1405 case JLE:
41feb04a 1406 return(n1 <= n2);
f00d91fc 1407 case JGE:
41feb04a 1408 return(n1 >= n2);
f00d91fc 1409 case JLT:
41feb04a 1410 return(n1 < n2);
f00d91fc 1411 case JGT:
41feb04a 1412 return(n1 > n2);
f00d91fc 1413 case JLO:
41feb04a 1414 return((unsigned) n1 < (unsigned) n2);
f00d91fc 1415 case JHI:
41feb04a 1416 return((unsigned) n1 > (unsigned) n2);
f00d91fc 1417 case JLOS:
41feb04a 1418 return((unsigned) n1 <= (unsigned) n2);
f00d91fc 1419 case JHIS:
41feb04a 1420 return((unsigned) n1 >= (unsigned) n2);
f00d91fc
BJ		 1421 }
1422 return(0);
1423}
1424
1425setcon(cv, cl, type)
1426register char *cv, *cl;
1427{
1428 register char *p;
1429
1430 if (*cv != '$')
1431 return;
1432 if (!natural(cl))
1433 return;
1434 p = conloc;
1435 while (*p++ = *cl++);
1436 p = conval;
1437 *p++ = type;
1438 while (*p++ = *cv++);
1439}
1440
1441equstr(p1, p2)
1442register char *p1, *p2;
1443{
1444 do {
1445 if (*p1++ != *p2)
1446 return(0);
1447 } while (*p2++);
1448 return(1);
1449}
1450
1451setcc(ap,type)
1452char *ap;
1453{
1454 register char *p, *p1;
1455
1456 p = ap;
1457 if (!natural(p)) {
1458 ccloc[0] = 0;
1459 return;
1460 }
1461 p1 = ccloc;
1462 *p1++ = type;
1463 while (*p1++ = *p++);
1464}
1465
1466okio(p) register char *p; {/* 0->probable I/O space address; 1->not */
1467 if (ioflag && (!natural(p) || 0>getnum(p))) return(0);
1468 return(1);
1469}
1470
1471indexa(p) register char *p; {/* 1-> uses [r] addressing mode; 0->doesn't */
1472 while (*p) if (*p++=='[') return(1);
1473 return(0);
1474}
1475
1476natural(p)
1477register char *p;
1478{/* 1->simple local, parameter, global, or register; 0->otherwise */
6b028d93 1479 if (*p=='*' || *p=='(' || *p=='-'&&p[1]=='(' || *p=='$'&&getnum(p+1))
f00d91fc
BJ		 1480 return(0);
1481 while (*p++);
1482 p--;
6b028d93 1483 if (*--p=='+' || *p==']' || *p==')' && p[-2]!='a' && p[-2]!='f')
f00d91fc
BJ		 1484 return(0);
1485 return(1);
1486}
1487
1488/*
1489** Tell if an argument is most likely static.
1490*/
1491
1492isstatic(cp)
1493register char *cp;
1494{
1495 if (*cp == '_' || *cp == 'L' || (*cp++ == 'v' && *cp == '.'))
1496 return (1);
1497 return (0);
1498}
49c27f9c
RC		 1499
1500autoid(p) register char *p; {/* 1-> uses autoincrement/autodecrement; 0->doesn't */
1501 if (*p == '-' && *(p+1) == '(') return(1);
1502 while (*p) p++;
1503 if (*--p == '+' && *--p == ')') return(1);
1504 return(0);
1505 }
Continuous source code history from original PDP-7 UNIX to FreeBSD 2, the first fully unencumbered FreeBSD release.