projects / unix-history / blame
? search:
summary | tags | clone url | shortlog | log | commit | commitdiff | tree
blob | blame (incremental) | history | HEAD
BSD 4_3_Tahoe release
[unix-history] / usr / src / lib / c2 / c2.tahoe / c21.c
CommitLineData
3347ccab 1#ifndef lint
ca67e7b4 2static char sccsid[] = "@(#)c21.c 1.9 (Berkeley/CCI) 5/12/88";
3347ccab
SL		 3#endif
4
5/*
6 * C object code improver-- second part
7 */
8
9#include "c2.h"
10#include <stdio.h>
11#include <ctype.h>
12
13int bitsize[] = {0,8,16,32,64,32,64}; /* index by type codes */
14
15redun3(p) register struct node *p; {
16/* check for 3 addr instr which should be 2 addr */
864f1f35 17 if (has3ops(p)) {
3347ccab
SL		 18 if (equstr(regs[RT1],regs[RT3])
19 && (p->op==ADD || p->op==MUL || p->op==AND || p->op==OR || p->op==XOR)) {
20 register char *t=regs[RT1]; regs[RT1]=regs[RT2]; regs[RT2]=t;
21 }
22 if (equstr(regs[RT2],regs[RT3])) {
23 p->subop=(p->subop&0xF)|(OP2<<4); p->pop=0;
24 lastrand=regs[RT2]; *regs[RT3]=0; return(1);
25 }
26 } return(0);
27}
28
29bmove() {
30 register struct node *p, *lastp; register char *cp1,*cp2; register int r;
31 struct node *flops();
32
33 refcount();
34 for (p=lastp= &first; 0!=(p=p->forw); lastp=p);
35 clearreg(); clearuse();
36 for (p=lastp; p!= &first; p=p->back) {
37 if (debug) {
38 printf("Uses: ");
39 if (useacc)
40 printf("acc: %s\n",useacc->code? useacc->code:"");
41 for (r=NUSE;--r>=0;) if (uses[r])
42 printf("%d: %s\n",r,uses[r]->code? uses[r]->code:"");
43 printf("-\n");
44 }
45 r=(p->subop>>4)&0xF;
46 splitrand(p);
47 if (OP3==r && 0!=redun3(p)) {newcode(p); redunm++;}
48 /* ops that do nothing */
49 if(p->op==MOV && equstr(regs[RT1], regs[RT2]))
50 if(p->forw->op!=CBR) {
51 delnode(p); redunm++; continue;
52 } else {
53 p->op=TST; p->pop=0;
54 while(*p->code++ != ',');
55 redunm++;
56 }
57 else if((cp1=p->code, *cp1++)=='$' &&
58 (*cp1=='0' || *cp1=='1' || *cp1++=='-' && *cp1=='1') && cp1[1]==',') {
864f1f35
SL		 59 switch((p->code[1]<<8)|ord(p->op)) {
60 case (('0'<<8)|ord(ADD)):
61 case (('0'<<8)|ord(SUB)):
62 case (('-'<<8)|ord(AND)):
63 case (('0'<<8)|ord(OR)):
64 case (('0'<<8)|ord(XOR)):
65 case (('1'<<8)|ord(MUL)):
66 case (('1'<<8)|ord(DIV)):
67 case (('0'<<8)|ord(SHAL)):
68 case (('0'<<8)|ord(SHAR)):
69 case (('0'<<8)|ord(SHL)):
70 case (('0'<<8)|ord(SHR)):
3347ccab
SL		 71 if(r == OP2) {
72 if(p->forw->op!=CBR) {
73 delnode(p); redunm++; continue;
74 } else {
75 p->op=TST; p->subop&=0xF; p->pop=0;
76 while(*p->code++ != ',');
77 redunm++;
78 }
79 } else { /* OP3 or shift */
80 p->op=MOV; p->subop&=0xF; p->pop=0;
81 while(*p->code++ != ',');
82 p = p->forw; redunm++; continue;
83 }
84 break;
864f1f35
SL		 85 case (('0'<<8)|ord(MUL)):
86 case (('0'<<8)|ord(AND)):
3347ccab
SL		 87 p->op=CLR; p->subop&=0xF; p->pop=0;
88 while(*p->code++ != ',');
89 if(r == OP3)
90 while(*p->code++ != ',');
91 redunm++;
92 }
93 }
94 switch (p->op) {
95 case LABEL: case DLABEL:
96 for (r=NUSE; --r>=0;)
97 if (uses[r]) p->ref=(struct node *) (((int)p->ref)|(1<<r));
98 if (useacc) p->ref=(struct node *) (((int)p->ref)|(1<<NUSE));
99 break;
100 case CALLS:
101 case CALLF:
102 clearuse(); goto std;
864f1f35 103 case NIL:
3347ccab
SL		 104 clearuse(); break;
105 case CVT:
106 { long n;
107 if ((p->subop&0xF)!=LONG) goto std; cp1=p->code;
108 if (*cp1++!='$') goto std; splitrand(p);
109 n = getnum(&regs[RT1][1]);
110 if(r==BYTE && (n<-128 || n>127)) goto std;
111 if(r==WORD && (n<-32768 || n>32767)) goto std;
112 p->op = MOV; p->subop = r; p->pop = 0;
113 } goto std;
114
115 case SUB:
116 if ((p->subop&0xF)!=LONG) goto std; cp1=p->code;
117 if (*cp1++!='$') goto std; splitrand(p);
118#ifdef MOVAFASTER
119 if (equstr(regs[RT2],"fp") && !indexa(regs[RT1])) {/* address comp. */
120 char buf[C2_ASIZE]; cp2=buf; *cp2++='-';
121 cp1=regs[RT1]+1; while (*cp2++= *cp1++); --cp2;
122 cp1="(fp),"; while (*cp2++= *cp1++); --cp2;
123 cp1=regs[RT3]; while (*cp2++= *cp1++);
124 p->code=copy(buf); p->op = MOVA; p->subop = BYTE; p->pop=0;
125 } else
126#endif MOVAFASTER
e6c8f4f3
SL		 127 if (*cp1++=='-' && 0==(r=getnum(cp1)) &&
128 !checkexpr(cp1)) {
3347ccab
SL		 129 p->op=ADD; p->pop=0; *--cp1='$'; p->code=cp1;
130 } goto std;
131 case ADD:
132 if ((p->subop&0xF)!=LONG) goto std; cp1=p->code;
133 if (*cp1++!='$') goto std; splitrand(p);
864f1f35 134 if (isstatic(cp1) && tempreg(regs[RT2],r) && uses[r]==p->forw)
3347ccab
SL		 135 {
136 /* address comp:
137 ** addl2 $_foo,r0 \ movab _foo[r0],bar
138 ** movl r0,bar /
139 */
140 register struct node *pnext = p->forw;
141 char buf[C2_ASIZE];
142
143 if (pnext->op == MOV && pnext->subop == LONG)
144 {
145 cp1 = &regs[RT1][1]; cp2 = &buf[0];
146 while (*cp2++ = *cp1++) ; cp2--;
147 splitrand(pnext);
148 if (r == isreg(regs[RT1]))
149 {
150 delnode(p); p = pnext;
151 p->op = MOVA; p->subop = BYTE;
152 p->pop = 0;
153 cp1 = regs[RT1]; *cp2++ = '[';
154 while (*cp2++ = *cp1++) ; cp2--;
155 *cp2++ = ']'; *cp2++ = ',';
156 cp1 = regs[RT2];
157 while (*cp2++ = *cp1++) ;
158 p->code = copy(buf);
159 }
160 }
161 }
162 else
163#ifdef MOVAFASTER
164 if (equstr(regs[RT2],"fp") && !indexa(regs[RT1])) {/* address comp. */
165 cp2=cp1-1; cp1=regs[RT1]+1; while (*cp2++= *cp1++); --cp2;
166 cp1="(fp)"; while (*cp2++= *cp1++); *--cp2=',';
167 p->op = MOVA; p->subop = BYTE; p->pop=0;
168 } else
169#endif MOVAFASTER
e6c8f4f3
SL		 170 if (*cp1++=='-' && 0==(r=getnum(cp1)) &&
171 !checkexpr(cp1)) {
3347ccab
SL		 172 p->op=SUB; p->pop=0; *--cp1='$'; p->code=cp1;
173 }
174 /* fall thru ... */
175 case CASE:
176 default: std:
177 p=bflow(p); break;
178
179 case MUL:
180 /*
181 ** Change multiplication
182 ** by constant powers of 2 to shifts.
183 */
184 splitrand(p);
185 if (regs[RT1][0] != '$' || regs[RT1][1] == '-') goto std;
186 if ((r = ispow2(getnum(&regs[RT1][1]))) <= 0) goto std;
187 /* mull2 $2,x */
188 if(r == 1 && p->subop == U(LONG, OP2)) {
189 strcpy(regs[RT1], regs[RT2]);
190 p->op = ADD; p->pop = 0; newcode(p);
191 goto std;
192 }
193 if (p->subop == U(LONG,OP2))
194 strcpy(regs[RT3], regs[RT2]);
195 sprintf(regs[RT1], "$%d", r);
196 p->op = SHL; p->subop = LONG;
197 p->pop = 0; newcode(p);
198 goto std;
199
200 case SHAL:
201 case SHL:
202 {
203 /* bit tests:
204 ** shll A,$1,rC \
205 ** bitl B,rC > jbc A,B,D
206 ** jeql D /
207 **
208 ** address comp:
209 ** shll $1,bar,r0 \ movl bar,r0
210 ** movab _foo[r0] / movaw _foo[r0]
211 **
212 ** shll $2,r0,r0 \ moval _foo[r0]
213 ** movab _foo[r0] /
214 */
215 register struct node *pf;
216 register struct node *pn;
217 register int shfrom, shto;
218 long shcnt;
219 char *regfrom;
220
221 splitrand(p);
222 if (regs[RT1][0] != '$') {
223 if(isreg(regs[RT1]) < 0) goto std; /* alignment */
224 if (regs[RT2][0] != '$') goto std;
225 if (getnum(&regs[RT2][1]) != 1) goto std;
864f1f35 226 if (!tempreg(regs[RT3],r)) goto std;
3347ccab
SL		 227 if ((pf = p->forw)->op != BIT && pf->op!=AND) goto std;
228 if (uses[r] && uses[r] != pf) goto std;
229 splitrand(pf);
230 if (r == isreg(regs[RT1])) cp2 = regs[RT2];
231 else if (r == isreg(regs[RT2])) cp2 = regs[RT1];
232 else goto std;
233 if (*cp2 == '$') goto std;
234 if ((pn = pf->forw)->op != CBR) goto std;
235 if (pn->subop != JEQ && pn->subop != JNE) goto std;
236 delnode(p); delnode(pf);
237 pn->subop = (pn->subop == JEQ) ? JBC : JBS;
238 for(cp1=p->code; *cp1++!=',';);
239 while (*cp1++= *cp2++);
240 pn->code = p->code; pn->pop = NULL;
241 uses[r] = NULL;
242 nbj++;
243 p = pn;
244 goto std;
245 }
246 if ((shcnt = getnum(&regs[RT1][1])) < 1 || shcnt > 2) goto std;
247 if ((shfrom = isreg(regs[RT2])) >= 0)
248 regfrom = copy(regs[RT2]);
864f1f35 249 if (tempreg(regs[RT3],shto))
3347ccab
SL		 250 {
251 int regnum;
252
253 if (uses[shto] != (pf = p->forw)) goto ashadd;
254 if (pf->op != MOVA && pf->op != PUSHA) goto ashadd;
255 if (pf->subop != BYTE) goto ashadd;
256 splitrand(pf);
257 if (!indexa(regs[RT1])) goto std;
258 cp2 = regs[RT1];
259 if(!isstatic(cp2)) goto std;
260 while (*cp2++ != '[') ;
261 if (*cp2++ != 'r' || !isdigit(*cp2)) goto std;
262 regnum = *cp2++ - '0';
263 if (isdigit(*cp2))
264 {
265 if (cp2[1] != ']') goto std;
266 regnum *= 10; regnum += *cp2 - '0';
267 }
268 if (regnum != shto) goto std;
269 if (shfrom >= 0) /* shll $N,r*,r0 */
270 {
271 delnode(p);
272 p = pf;
273 if (shfrom != shto)
274 {
275 uses[shto] = NULL; splitrand(pf);
276 cp2=regs[RT1]; while (*cp2++!='[');
277 cp1=regfrom; while (*cp2++= *cp1++);
278 cp2[-1] = ']'; *cp2 = 0;
279 newcode(pf);
280 }
281 }
282 else
283 {
284 p->op = MOV; splitrand(p);
285 strcpy(regs[RT1], regs[RT2]);
286 strcpy(regs[RT2], regs[RT3]);
287 regs[RT3][0] = '\0';
288 p->pop = 0; newcode(p);
289 }
290 switch (shcnt)
291 {
292 case 1: pf->subop = WORD; break;
293 case 2: pf->subop = LONG; break;
294 }
3c2c00f3 295 pf->pop = 0;
3347ccab
SL		 296 redunm++; nsaddr++;
297 }
ca67e7b4 298 goto std;
3347ccab
SL		 299ashadd:
300 /* at this point, RT2 and RT3 are guaranteed to be simple regs*/
301 if (shcnt == 1) {
302 /*
303 ** quickie:
304 ** shll $1,A,A > addl2 A,A
305 ** shll $1,A,B > addl3 A,A,B
306 */
307 p->op = ADD;
308 strcpy(regs[RT1], regs[RT2]);
309 if(equstr(regs[RT2], regs[RT3])) {
310 p->subop = U(LONG,OP2);
311 regs[RT3][0] = '\0';
312 } else
313 p->subop = U(LONG,OP3);
314 p->pop = 0;
315 newcode(p);
316 }
317 goto std;
318 }
319
320 case SHAR:
321 case SHR:
322 {
323 /* bit tests:
324 ** shrl A,B,rC \
325 ** bitl $1,rC > jbc A,B,D
326 ** jeql D /
327 */
328 register struct node *pf; /* forward node */
329 register struct node *pn; /* next node (after pf) */
330 register int extreg; /* reg extracted to */
331
332 splitrand(p);
333 if(isreg(regs[RT1]) < 0) goto std; /* alignment */
864f1f35 334 if (!tempreg(regs[RT3],extreg)) goto std;
3347ccab
SL		 335 if ((pf = p->forw)->op != BIT) goto std;
336 if (uses[extreg] && uses[extreg] != pf) goto std;
337 splitrand(pf);
338 if (regs[RT1][0] != '$') goto std;
339 if (getnum(&regs[RT1][1]) != 1) goto std;
340 if (extreg != isreg(regs[RT2])) goto std;
341 if ((pn = pf->forw)->op != CBR) goto std;
342 if (pn->subop != JEQ && pn->subop != JNE) goto std;
343 delnode(p); delnode(pf);
344 pn->subop = (pn->subop == JEQ) ? JBC : JBS;
345 for(cp1=p->code; *cp1++!=',';);
346 while (*cp1!=',') cp1++; *cp1='\0';
347 pn->code = p->code; pn->pop = NULL;
348 uses[extreg] = NULL; nbj++;
349 p = pn;
350 goto std;
351 }
352
353 case AND:
354 {
355 /* unsigned conversion:
356 ** cvtbl A,B; andl2 $255,B > movzbl A,B
357 **
358 ** also byte- and word-size fields:
359 ** shrl $(3-n)*8,A,B; andl2 $255,B > movzbl n+A,B
360 ** shrl $(1-n)*16,A,B; andl2 $65535,B > movzwl n+A,B
361 */
362 char src[C2_ASIZE];
363 register int f; /* field length */
364 register struct node *pb = p->back; /* backward node */
365
366 if (p->subop != U(LONG,OP2))
367 goto std;
368 splitrand(p); cp1=regs[RT1];
369 if (*cp1++!='$' || (f=getnum(cp1))!=0xff && f!=0xffff)
370 goto std;
371 f = f==0xff ? 8 : 16;
372 if (pb->op!=CVT && pb->op!=MOVZ && pb->op!=SHAR && pb->op!=SHR)
373 goto std;
374 /* save source of ANDL in 'src' */
375 strcpy(src, regs[RT2]);
376 splitrand(pb);
377 if (!equstr(src,lastrand))
378 goto std;
379 if (pb->op==CVT || pb->op==MOVZ) {
380 if (!(bitsize[pb->subop&0xF]==f
381 && bitsize[pb->subop>>4]>=f)) /* good CVT */
382 goto std;
383 strcpy(src, regs[RT1]);
384 } else {
385 register int boff; /* bit offset */
386
387 if (regs[RT1][0] != '$') goto std;
388 if ((boff = getnum(&regs[RT1][1])) < 0) goto std;
389 if (isreg(regs[RT2])>=0 || !natural(regs[RT2])) goto std;
390 if ((boff & (f-1)) != 0) goto std;
391 boff = (32-boff-f) / 8;
392 if (boff == 0)
393 strcpy(src, regs[RT2]);
394 else
395 sprintf(src, "%d%s%s", boff, regs[RT2][0]=='(' ? "":"+",
396 regs[RT2]);
397 }
398 delnode(pb);
399 p->op = MOVZ;
400 p->subop = U((f==8 ? BYTE : WORD), LONG);
401 sprintf(line,"%s,%s",src,lastrand);
402 p->pop=0;
403 p->code = copy(line);
404 goto std;
405 }
406
407 case CMP:
408 {
409 /* comparison to -63 to -1:
410 ** cmpl r0,$-1 > incl r0
411 ** jeql ...
412 **
413 ** cmpl r0,$-63 > addl2 $63,r0
414 ** jeql ...
415 */
416 register int num;
417 register int reg;
418 register struct node *regp = p->back;
419
420 if (p->forw->op != CBR) goto std;
421 if (p->forw->subop != JEQ && p->forw->subop != JNE) goto std;
422 splitrand(p);
423 if (strncmp(regs[RT2], "$-", 2) != 0) goto std;
424 reg = r = isreg(regs[RT1]);
425 if (r < 0) goto std;
426 if (r < NUSE && uses[r] != 0) goto std;
427 if (r >= NUSE && regp->op == MOV && p->subop == regp->subop)
428 {
429 if (*regp->code != 'r') goto std;
430 reg = regp->code[1] - '0';
431 if (isdigit(regp->code[2]) || reg >= NUSE || uses[reg])
432 goto std;
433 }
434 if (r >= NUSE) goto std;
435 if (reg != r)
436 sprintf(regs[RT1], "r%d", reg);
437 if ((num = getnum(&regs[RT2][2])) <= 0 || num > 63) goto std;
438 if (num == 1)
439 {
440 p->op = INC; regs[RT2][0] = '\0';
441 }
442 else
443 {
444 register char *t;
445
446 t=regs[RT1];regs[RT1]=regs[RT2];regs[RT2]=t;
447 p->op = ADD; p->subop = U(p->subop, OP2);
448 for (t = &regs[RT1][2]; t[-1] = *t; t++) ;
449 }
450 p->pop = 0; newcode(p);
451 goto std;
452 }
453
454 case JBR: case JMP:
455 clearuse();
456 if ((p->subop&0xF)==RET) {
457 switch((p->subop>>4)&0xF) {
458 case 2: uses[1]=p; regs[1][0]= -1;
459 case 1: uses[0]=p; regs[0][0]= -1;
460 }
461 break;
462 }
463 if (p->ref==0) goto std; /* jmp (r0) */
464 /* fall through */
465 case CBR:
466 if (p->ref->ref!=0) {
467 for (r=NUSE;--r>=0;)
468 if ((1<<r) & (int)p->ref->ref) {uses[r]=p; regs[r][0]= -1;}
469 if ((1<<NUSE) & (int)p->ref->ref) useacc=p;
470 }
471 break;
472 case LNF:
473 /* lnf a; addf b ==> ldf b; subf a */
474 { register struct node *pf = p->forw;
475 if(pf->op==ADDF && p->subop==pf->subop) {
476 p->op = LDF;
477 p->pop = 0;
478 pf->op = SUBF;
479 pf->pop = 0;
480 cp1 = p->code;
481 p->code = pf->code;
482 pf->code = cp1;
483 p = pf->forw;
484 break;
485 }}
486 case LDF: case LDFD: case CVLF: /* destroy acc */
487 useacc = 0;
488 goto std;
489 case STF:
490 { register struct node *pf;
491 if((pf=flops(p)) != p) {
492 p = pf; /* usually p->forw; */
493 break;
494 }}
495 if(ldmov(p)) {
496 p = p->forw;
497 break;
498 }
499 if(useacc == 0)
500 useacc = p;
501 goto std;
502 case ADDF: case MULF: /* commutatives - create clients for flops */
503 /* stf a; ldf b; addf a => stf a; ldf a; addf b */
504 { register struct node *pb = p->back;
505 register struct node *pbb = pb->back;
506 if(pb->op==LDF && pb->subop==p->subop &&
507 pbb && pbb->op==STF && pbb->subop==p->subop &&
508 equstr(pbb->code, p->code)) {
509 cp1 = p->code;
510 p->code = pb->code;
511 pb->code = cp1;
512 }}
513 /* use acc and regs */
514 case CMPF: case CVFL: case SUBF: case DIVF:
515 if(useacc == 0)
516 useacc = p;
517 goto std;
e6c8f4f3
SL		 518 case TSTF:
519 break;
520 case PUSHD:
3347ccab
SL		 521 if(ldmov(p)) {
522 p = p->forw;
523 break;
524 }
525 case CVDF: case NEGF: /* use only acc */
526 case SINF: case COSF: case ATANF: case LOGF: case SQRTF: case EXPF:
527 if(useacc == 0)
528 useacc = p;
529 case EROU: case JSW:
530 case TEXT: case DATA: case BSS: case ALIGN: case WGEN: case END: ;
531 }
532 }
533 for (p= &first; p!=0; p=p->forw)
534 if (p->op==LABEL || p->op==DLABEL) p->ref=0; /* erase our tracks */
535}
536
537char *
538byondrd(p) register struct node *p; {
539/* return pointer to register which is "beyond last read/modify operand" */
864f1f35 540 if (has2ops(p)) return(regs[RT3]);
3347ccab
SL		 541 switch (p->op) {
542 case MFPR:
543 case PUSHA:
544 case TST: case INC: case DEC: case PUSH:
545 case LDF: case LNF: case CVLF: case LDFD:
546 case ADDF: case SUBF: case MULF: case DIVF:
547 case CMPF:
548 return(regs[RT2]);
549 case MTPR:
550#ifndef EMOD
551 case EDIV:
552#endif EMOD
553 case CBR: /* must be JBC/JBS */
554 case BIT: case CMP: case CALLS: case CALLF:
555 case CMPF2:
556 return(regs[RT3]);
557 case EMUL:
558 case PROBE:
559 case MOVBLK:
560 case CASE:
561 return(regs[RT4]);
562 }
563 return(lastrand);
564}
565
566struct node *
567bflow(p)
864f1f35 568 register struct node *p;
3347ccab
SL		 569{
570 register char *cp1,*cp2,**preg;
571 register int r, fr, dblflg=0;
572 int flow= -1;
573 struct node *olduse=0, *olduse1=0;
574
e22e545c
DS		 575 if (p->subop==QUAD || p->subop==DOUBLE || (p->subop&0xF0)==DOUBLE<<4 ||
576 p->op==EMUL)
3347ccab 577 dblflg |= 1; /* double dest */
864f1f35 578 if ((p->subop&0xF)==DOUBLE || p->subop==QUAD)
3347ccab
SL		 579 dblflg |= 2; /* double src */
580 splitrand(p);
864f1f35 581 if (p->op!=PUSH &&
3347ccab 582#ifndef EMOD
864f1f35 583 p->op!=EDIV &&
3347ccab 584#endif EMOD
864f1f35
SL		 585 p->op!=EMUL &&
586 p->subop && tempreg(lastrand,r) && uses[r]==p->forw) {
587 if (equtype(p->subop,regs[r][0]) ||
588 ((p->op==CVT || p->op==MOVZ || p->op==CVFL) &&
589 (regs[r][0]&0xf) && compat((p->subop>>4)&0xf,regs[r][0])) ||
590 p->op==MOVA && compat(LONG, regs[r][0])) {
3347ccab 591 register int r2;
864f1f35
SL		 592
593 if (regs[r][1]!=0) { /* send directly to destination */
3347ccab 594 if (p->op==INC || p->op==DEC) {
864f1f35
SL		 595 p->op = (p->op==DEC) ? SUB : ADD;
596 /* use 2 now, convert to 3 later */
597 p->subop=(OP2<<4)+(p->subop&0xF);
3347ccab 598 p->pop=0;
864f1f35
SL		 599 cp1=lastrand; cp2=regs[RT2];
600 while (*cp2++= *cp1++) /* copy reg */
601 ;
3347ccab
SL		 602 cp1=lastrand; *cp1++='$'; *cp1++='1'; *cp1=0;
603 }
604 cp1=regs[r]+1; cp2=lastrand;
864f1f35
SL		 605 if (has2ops(p)) {
606 /* use 3 operand form of instruction */
3347ccab 607 p->pop=0;
864f1f35
SL		 608 p->subop += (OP3-OP2)<<4;
609 lastrand = cp2 = regs[RT3];
3347ccab 610 }
864f1f35
SL		 611 while (*cp2++= *cp1++)
612 ;
3347ccab
SL		 613 if (p->op==MOVA && p->forw->op==PUSH) {
614 p->op=PUSHA;
615 *regs[RT2]=0; p->pop=0;
864f1f35
SL		 616 } else if ((p->op==MOV || p->op==CVT) &&
617 p->forw->op==PUSH) {
3347ccab
SL		 618 p->op=PUSH; p->subop &= 0xF;
619 *regs[RT2]=0; p->pop=0;
620 }
621 delnode(p->forw);
864f1f35
SL		 622 if (tempreg(lastrand,r2))
623 uses[r2]=uses[r], uses[r]=0;
3347ccab
SL		 624 redun3(p);
625 newcode(p); redunm++; flow=r;
864f1f35 626 } else if (p->op==MOV) { /* superfluous fetch */
3347ccab
SL		 627 int nmatch;
628 char src[C2_ASIZE];
629 movit:
864f1f35
SL		 630 for (cp2=src, cp1=regs[RT1]; *cp2++= *cp1++;)
631 ;
3347ccab
SL		 632 splitrand(p->forw);
633 if (p->forw->op != INC && p->forw->op != DEC)
634 lastrand=byondrd(p->forw);
635 nmatch=0;
636 for (preg=regs+RT1;*preg!=lastrand;preg++)
637 if (r==isreg(*preg)) {
864f1f35
SL		 638 cp2= *preg; cp1=src;
639 while (*cp2++= *cp1++)
640 ;
641 ++nmatch;
3347ccab
SL		 642 }
643 if (nmatch==1) {
864f1f35 644 if (has2ops(p->forw) && equstr(src,regs[RT2])) {
3347ccab 645 p->forw->pop=0;
864f1f35
SL		 646 p->forw->subop += (OP3-OP2)<<4;
647 cp1=regs[RT3];
648 *cp1++ = 'r'; *cp1++ = r+'0'; *cp1=0;
3347ccab 649 }
864f1f35
SL		 650 delnode(p);
651 p=p->forw;
652 if (tempreg(src,r2))
653 uses[r2]=uses[r], uses[r]=0;
3347ccab 654 redun3(p);
e0921d75
DS		 655 newcode(p); redunm++;
656 return(p); /* avoid stale uses[] data */
864f1f35
SL		 657 } else
658 splitrand(p);
3347ccab 659 }
864f1f35
SL		 660 } else if (p->op==MOV && (p->forw->op==CVT || p->forw->op==MOVZ) &&
661 p->forw->subop&0xf && /* if base or index, then forget it */
662 compat(p->subop,p->forw->subop) && !indexa(cp1=regs[RT1]))
663 goto movit;
3347ccab
SL		 664 }
665 /* adjust 'lastrand' past any 'read' or 'modify' operands. */
666 lastrand=byondrd(p);
667 /* a 'write' clobbers the register. */
864f1f35
SL		 668 if (tempreg(lastrand,r) ||
669 (has2ops(p) && tempreg(regs[RT2],r) && uses[r]==0)) {
670 /*
671 * Writing a dead register is useless,
672 * but watch side effects
673 */
3347ccab
SL		 674 switch (p->op) {
675#ifndef EMOD
676 case EDIV:
677#endif EMOD
864f1f35
SL		 678 case AOBLEQ: case AOBLSS:
679 break;
3347ccab 680 default:
864f1f35
SL		 681 /*
682 * If no direct uses, check for
683 * use of condition codes
684 */
3347ccab 685 if (uses[r]==0 && ((dblflg&1)==0 || uses[r+1]==0)) {
864f1f35
SL		 686 register struct node *q = p;
687
688 while ((q = nonlab(q->forw))->op==JBR &&
689 q->subop==0)
690 q=q->ref; /* cc unused, unchanged */
691 if (q->op!=CBR && q->op!=ADDA && q->op!=SUBA) {
692 /* ... and destroyed */
3347ccab 693 preg=regs+RT1;
864f1f35
SL		 694 while (cp1 = *preg++) {
695 if (cp1==lastrand &&
696 p->op != CLR &&
697 p->op != CVFL) {
698 redunm++;
699 delnode(p);
700 return(p->forw);
701 }
702 if (equstr(cp1,lastrand))
703 break;
3347ccab
SL		 704 }
705 }
706 }
707 flow=r;
708 }
709 }
864f1f35
SL		 710 if ((r=flow) >= 0) {
711 olduse=uses[r], uses[r]=0;
712 *(short *)(regs[r])=0;
3347ccab 713 /* if r0 destroyed, dont keep r1 */
864f1f35
SL		 714 if (dblflg&1) {
715 olduse1=uses[++r], uses[r]=0;
716 *(short *)(regs[r])=0;
3347ccab
SL		 717 }
718 }
719 /* now look for 'read' or 'modify' (read & write) uses */
720 preg=regs+RT1;
721 while (*(cp1= *preg++)) {
722 /* check for r */
6e32ca3e
DS		 723 if (lastrand!=cp1 && tempreg(cp1,r)) {
724 int isunused;
725 if (isunused=(uses[r]==0)) {
726 uses[r]=p;
727 cp2=regs[r]; *cp2++=p->subop;
728 if ((p->op==SHAL || p->op==SHAR ||
729 p->op==SHL || p->op==SHR) &&
730 cp1==regs[RT1])
731 cp2[-1] = BYTE;
732 if (p->op==CBR && (p->subop==JBC || p->subop==JBS))
733 cp2[-1] = LONG;
734 if (p->op==MOVA && cp1==regs[RT2])
735 cp2[-1]=LONG;
736 }
3347ccab 737 /* ediv/emod's 2nd operand is quad */
864f1f35 738 if (((p->op==EDIV
3347ccab 739#ifdef EMOD
864f1f35 740 || p->op==EMOD
3347ccab 741#endif EMOD
864f1f35
SL		 742 ) && cp1==regs[RT2] || (dblflg&2)) &&
743 ++r<NUSE && uses[r]==0) {
6e32ca3e
DS		 744 if (isunused)
745 *cp2=0;
864f1f35
SL		 746 uses[r]=p;
747 cp2=regs[r]; *cp2++=p->subop;
6e32ca3e
DS		 748 if (!isunused)
749 *cp2=0;
3347ccab 750 }
6e32ca3e
DS		 751 if (!isunused)
752 continue;
864f1f35
SL		 753 if (p->op==MOV || p->op==PUSH || p->op==CVT ||
754 p->op==MOVZ || p->op==COM || p->op==NEG ||
755 p->op==STF) {
756 if (p->op!=PUSH) {
3347ccab 757 cp1=regs[RT2];
864f1f35
SL		 758 if (tempreg(cp1,r)) {
759 /*
760 * reincarnation!!
761 * (as in addl2 r0,r1;
762 * movl r1,r0; ret)
763 */
764 if (uses[r]==0)
3347ccab 765 uses[r]=olduse;
864f1f35 766 if ((dblflg&1) && uses[r+1]==0)
3347ccab
SL		 767 uses[r+1]=olduse1;
768 }
864f1f35
SL		 769 if (p->op!=MOV)
770 cp1=0;
771 } else
772 cp1="-(sp)";
773 if (cp1)
774 while (*cp2++= *cp1++)
775 ;
776 else
777 *cp2=0;
778 } else
779 *cp2=0;
3347ccab
SL		 780 continue;
781 }
782 /* check for (r),[r] */
864f1f35
SL		 783 do {
784 if (*cp1=='(' || *cp1=='[') { /* get register number */
785 char t;
786 for (cp2= ++cp1; *++cp1!=')' && *cp1!=']';)
787 ;
788 t= *cp1; *cp1=0;
789 if (tempreg(cp2,r) &&
790 (uses[r]==0 || uses[r]==p)) {
791 uses[r]=p;
792 regs[r][0] =
793 (*--cp2=='[' ? OPX<<4 : OPB<<4);
3c2c00f3 794 regs[r][1] = '\0';
864f1f35
SL		 795 }
796 *cp1=t;
3347ccab 797 }
3347ccab
SL		 798 } while (*++cp1);
799 }
800#ifdef MOVAFASTER
801 /* pushax or movax possibility? */
802 cp1=regs[RT1];
803 if (*cp1++=='$' && isstatic(cp1)) {
804 if (p->op==MOV && p->subop==LONG) {
805 if (regs[RT1][1]=='L' && 0!=(p->labno=getnum(regs[RT1]+2))) {
806 cp1=p->code; while (*cp1++!=','); p->code= --cp1;
807 }
808 p->op = MOVA; p->subop = BYTE; ++p->code; p->pop=0;
809 } else if (p->op==PUSH && p->subop==LONG) {
810 p->op = PUSHA; p->subop = BYTE; ++p->code; p->pop=0;
811 } else if (p->op==ADD && p->subop==U(LONG,OP3)
812 && 0<=(r=isreg(regs[RT2]))) {
813 cp1=cp2=p->code; ++cp1;
814 do *cp2++= *cp1; while (*cp1++!=','); cp2[-1]='[';
815 do *cp2++= *cp1; while (*cp1++!=','); cp2[-1]=']';
816 if (!equstr(regs[RT3],"-(sp)")){ p->op = MOVA; p->subop = BYTE;}
817 else {p->op = PUSHA; p->subop = BYTE; *cp2=0;}
818 if (uses[r]==0) {uses[r]=p; regs[r][0]=OPX<<4;}
819 p->pop=0;
820 }
821 }
822#endif MOVAFASTER
864f1f35 823 return (p);
3347ccab
SL		 824}
825
826/* try to eliminate STF's */
827struct node *
828flops(q)
829register struct node *q;
830{
831 register struct node *p;
832 register int r;
833
864f1f35 834 if(q->op!=STF || !tempreg(q->code,r))
3347ccab
SL		 835 return(q);
836 if(uses[r]) {
837 /* see if anyone destroys acc between us */
838 for(p=q->forw; p!=uses[r]; p=p->forw)
839 switch(p->op) {
840 case LABEL:
841 case LDF: case LNF: case CVLF: case LDFD:
842 case CVDF: case NEGF: case ADDF: case SUBF:
843 case MULF: case DIVF: case SINF: case COSF:
844 case ATANF: case LOGF: case SQRTF: case EXPF:
845 return(q);
846 }
3c2c00f3 847 again:
3347ccab
SL		 848 if(q->subop == p->subop)
849 switch(p->op) { /* do it in the accumulator */
850 case LDF: /* redundant load */
851 delnode(p); nld++;
852 p = p->forw;
853 break;
854 case LNF: /* stf r; lnf r ==> negf */
855 p->op = NEGF;
856 p->pop = 0;
857 p->code = 0;
858 break;
859 case CMPF2: /* stf r; cmpf2 r,x ==> cmpf x */
860 { register char *s;
861 register struct node *p1=p->forw;
862 for(s=p->code; *s!=','; s++);
863 *s = 0;
864 if(isreg(p->code) == r)
865 p->code = s+1;
866 else {
867 if(p1->op != CBR || isreg(s+1) != r) {
868 *s = ',';
869 return(q);
870 }
871 if(p1->subop > JNE) {
872 p1->subop ^= 1;
873 p1->pop = 0;
874 nrevbr++;
875 }
876 }
877 p->op = CMPF;
878 p->pop = 0;
879 }
880 break;
881 default:
882 return(q);
883 }
884 else if(p->subop==LONG) {
885 switch(p->op) {
886 case TST: /* stf r; tstl r ==> tstf */
887 p->op = TSTF;
888 p->code = 0;
889 break;
890 /* send directly to destination */
891 case MOV: /* stf r; movl r,x ==> stf x */
892 case PUSH: /* stf r; pushl r ==> stf -(sp)/pushd */
893 if(q->subop == DOUBLE) {
894 register struct node *b = p->back;
895 /* assume b's 2nd arg is ok */
896 if(!(b==uses[r+1] && b->op==p->op && b->subop==LONG))
897 return(q);
898 delnode(b); redunm++;
899 }
900 if(p->op==PUSH) {
901 if(q->subop == DOUBLE) {
902 p->op = PUSHD;
903 p->code = 0;
904 } else {
905 p->op = q->op;
906 p->code = copy("-(sp)");
907 }
908 } else {
909 p->op = q->op;
910 while(*p->code++ != ',');
911 }
912 break;
913 default:
914 return(q);
915 }
916 p->pop = 0;
917 p->subop = q->subop;
918 } else
919 return(q);
920 uses[r] = 0;
921 if(q->subop == DOUBLE)
922 uses[r+1] = 0;
3c2c00f3
DS		 923 for(p = p->back; p != q && (!uses[r] || !uses[r+1]); p = p->back) {
924 int xr;
925
926 splitrand(p);
927 if((xr=isreg(regs[RT1])) < 0)
928 continue;
929 if(!uses[r] && xr == r)
930 uses[r] = p;
931 else if(q->subop == DOUBLE && !uses[r+1] && xr == r+1)
932 uses[r+1] = p;
933 }
934 if(p = uses[r])
935 goto again;
d752722a 936 return(q->forw); /* DON'T re-scan code with dated uses[] */
3347ccab
SL		 937 }
938 /* it's a store to reg which isnt used elsewhere */
939 if((p=q->forw)->op == CBR) {
940 q->op = TSTF;
941 q->pop = 0;
942 q->code = 0;
943 } else {
944 delnode(q); nst++;
945 if(p->op ==STF || p->op==TSTF || p->op==PUSHD) {
946 if(useacc == p)
947 useacc = 0;
948 return(p->forw); /* so ldmov can be used on p */
949 }
950 }
951 return(p);
952}
953
954/* try to change load/store sequences to movl */
955ldmov(q)
956register struct node *q;
957{
958 register struct node *p;
959 register char *s, *pcod, *cp;
960 char *dlsw();
961
962 p = q->back;
963 if(!(useacc==0 && (q->op==STF || q->op==TSTF || q->op==PUSHD)
964 && ((p->op==LDF && p->subop==q->subop) || (p->op==LDFD && q->subop==DOUBLE))))
965 return(0);
966 pcod = p->code;
967 cp = p->code;
968 /* prepare args for movl/pushl */
969 if(q->op!=TSTF && q->subop==DOUBLE) {
970 if(p->op == LDF) {
971 if((s = dlsw(p->code)) == NULL)
972 return(0);
e6c8f4f3 973
3347ccab
SL		 974 strcpy(line, s);
975 if(q->op == STF) {
976 strcat(line, ",");
977 if((s = dlsw(q->code)) == NULL)
978 return(0);
979 strcat(line, s);
980 p->op = MOV;
981 } else
982 p->op = PUSH;
983 } else { /* LDFD */
984 if(q->op == STF) {
985 if((s = dlsw(q->code)) == NULL)
986 return(0);
987 } else
988 s = "-(sp)";
989 strcpy(line, s);
990 p->op = CLR;
991 }
992 p->pop = 0;
993 p->subop = LONG;
994 p->code = copy(line);
995 } else
996 {
997 if ((p->op == LDF) && (p->subop == DOUBLE) &&
998 (indexa(cp))) return(0);
999 delnode(p);
1000 }
1001 strcpy(line, pcod);
1002 if(q->op == STF) { /* ldf x; stf y ==> movl x,y */
1003 strcat(line, ",");
1004 strcat(line, q->code);
1005 q->op = MOV;
1006 nst++;
1007 } else if(q->op == TSTF) /* ldf x; tstf ==> tstl x */
1008 q->op = TST;
1009 else /* ldd x; pushd ==> pushl x+4; pushl x */
1010 q->op = PUSH;
1011 q->pop = 0;
1012 q->subop = LONG;
1013 q->code = copy(line);
1014 nld++;
1015 return(1);
1016}
1017
1018/* reconstruct the address of l.s.w. of a double operand */
1019char *
1020dlsw(d)
1021 register char *d;
1022{
e6c8f4f3 1023 register char *s, *t, *c;
3347ccab
SL		 1024 register int r;
1025 static char lsw[C2_ASIZE];
1026
1027 if(d[0] == '*' || d[0] == '$')
1028 return(NULL);
e6c8f4f3
SL		 1029 if (((strncmp(d, "(r", 2)) == 0) && isdigit(d[2]))
1030 return(NULL);
3347ccab
SL		 1031 t = lsw;
1032 if((r=isreg(d)) >= 0)
1033 sprintf(t, "r%d", r+1);
1034 else {
1035 for(s=d; *s && *s!='('; *t++ = *s++)
1036 if(*s == '[')
1037 return(NULL);
e6c8f4f3
SL		 1038 if(s!=d)
1039 *t++ = '+';
1040 *t++ = '4';
3347ccab 1041 while(*t++ = *s)
e6c8f4f3
SL		 1042 if(*s++ == '[' )
1043 {
3347ccab 1044 return(NULL);
e6c8f4f3 1045 }
3347ccab
SL		 1046 }
1047 return(lsw);
1048}
e6c8f4f3
SL		 1049checkexpr(p)
1050register char *p;
1051{
1052
1053 while(*p && *p != ','){
1054 if ((*p == '+' ) || (*p == '-'))
1055 return(1);
1056 *p++;
1057 }
1058 return(0);
1059}
Continuous source code history from original PDP-7 UNIX to FreeBSD 2, the first fully unencumbered FreeBSD release.