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add ifdef for IP_MAXPACKET
[unix-history] / usr / src / old / pcc / c2.tahoe / c21.c
CommitLineData
3347ccab 1#ifndef lint
e22e545c 2static char sccsid[] = "@(#)c21.c 1.7 (Berkeley/CCI) %G%";
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 }
295 redunm++; nsaddr++;
296 }
297 goto std;
298ashadd:
299 /* at this point, RT2 and RT3 are guaranteed to be simple regs*/
300 if (shcnt == 1) {
301 /*
302 ** quickie:
303 ** shll $1,A,A > addl2 A,A
304 ** shll $1,A,B > addl3 A,A,B
305 */
306 p->op = ADD;
307 strcpy(regs[RT1], regs[RT2]);
308 if(equstr(regs[RT2], regs[RT3])) {
309 p->subop = U(LONG,OP2);
310 regs[RT3][0] = '\0';
311 } else
312 p->subop = U(LONG,OP3);
313 p->pop = 0;
314 newcode(p);
315 }
316 goto std;
317 }
318
319 case SHAR:
320 case SHR:
321 {
322 /* bit tests:
323 ** shrl A,B,rC \
324 ** bitl $1,rC > jbc A,B,D
325 ** jeql D /
326 */
327 register struct node *pf; /* forward node */
328 register struct node *pn; /* next node (after pf) */
329 register int extreg; /* reg extracted to */
330
331 splitrand(p);
332 if(isreg(regs[RT1]) < 0) goto std; /* alignment */
864f1f35 333 if (!tempreg(regs[RT3],extreg)) goto std;
3347ccab
SL		 334 if ((pf = p->forw)->op != BIT) goto std;
335 if (uses[extreg] && uses[extreg] != pf) goto std;
336 splitrand(pf);
337 if (regs[RT1][0] != '$') goto std;
338 if (getnum(&regs[RT1][1]) != 1) goto std;
339 if (extreg != isreg(regs[RT2])) goto std;
340 if ((pn = pf->forw)->op != CBR) goto std;
341 if (pn->subop != JEQ && pn->subop != JNE) goto std;
342 delnode(p); delnode(pf);
343 pn->subop = (pn->subop == JEQ) ? JBC : JBS;
344 for(cp1=p->code; *cp1++!=',';);
345 while (*cp1!=',') cp1++; *cp1='\0';
346 pn->code = p->code; pn->pop = NULL;
347 uses[extreg] = NULL; nbj++;
348 p = pn;
349 goto std;
350 }
351
352 case AND:
353 {
354 /* unsigned conversion:
355 ** cvtbl A,B; andl2 $255,B > movzbl A,B
356 **
357 ** also byte- and word-size fields:
358 ** shrl $(3-n)*8,A,B; andl2 $255,B > movzbl n+A,B
359 ** shrl $(1-n)*16,A,B; andl2 $65535,B > movzwl n+A,B
360 */
361 char src[C2_ASIZE];
362 register int f; /* field length */
363 register struct node *pb = p->back; /* backward node */
364
365 if (p->subop != U(LONG,OP2))
366 goto std;
367 splitrand(p); cp1=regs[RT1];
368 if (*cp1++!='$' || (f=getnum(cp1))!=0xff && f!=0xffff)
369 goto std;
370 f = f==0xff ? 8 : 16;
371 if (pb->op!=CVT && pb->op!=MOVZ && pb->op!=SHAR && pb->op!=SHR)
372 goto std;
373 /* save source of ANDL in 'src' */
374 strcpy(src, regs[RT2]);
375 splitrand(pb);
376 if (!equstr(src,lastrand))
377 goto std;
378 if (pb->op==CVT || pb->op==MOVZ) {
379 if (!(bitsize[pb->subop&0xF]==f
380 && bitsize[pb->subop>>4]>=f)) /* good CVT */
381 goto std;
382 strcpy(src, regs[RT1]);
383 } else {
384 register int boff; /* bit offset */
385
386 if (regs[RT1][0] != '$') goto std;
387 if ((boff = getnum(&regs[RT1][1])) < 0) goto std;
388 if (isreg(regs[RT2])>=0 || !natural(regs[RT2])) goto std;
389 if ((boff & (f-1)) != 0) goto std;
390 boff = (32-boff-f) / 8;
391 if (boff == 0)
392 strcpy(src, regs[RT2]);
393 else
394 sprintf(src, "%d%s%s", boff, regs[RT2][0]=='(' ? "":"+",
395 regs[RT2]);
396 }
397 delnode(pb);
398 p->op = MOVZ;
399 p->subop = U((f==8 ? BYTE : WORD), LONG);
400 sprintf(line,"%s,%s",src,lastrand);
401 p->pop=0;
402 p->code = copy(line);
403 goto std;
404 }
405
406 case CMP:
407 {
408 /* comparison to -63 to -1:
409 ** cmpl r0,$-1 > incl r0
410 ** jeql ...
411 **
412 ** cmpl r0,$-63 > addl2 $63,r0
413 ** jeql ...
414 */
415 register int num;
416 register int reg;
417 register struct node *regp = p->back;
418
419 if (p->forw->op != CBR) goto std;
420 if (p->forw->subop != JEQ && p->forw->subop != JNE) goto std;
421 splitrand(p);
422 if (strncmp(regs[RT2], "$-", 2) != 0) goto std;
423 reg = r = isreg(regs[RT1]);
424 if (r < 0) goto std;
425 if (r < NUSE && uses[r] != 0) goto std;
426 if (r >= NUSE && regp->op == MOV && p->subop == regp->subop)
427 {
428 if (*regp->code != 'r') goto std;
429 reg = regp->code[1] - '0';
430 if (isdigit(regp->code[2]) || reg >= NUSE || uses[reg])
431 goto std;
432 }
433 if (r >= NUSE) goto std;
434 if (reg != r)
435 sprintf(regs[RT1], "r%d", reg);
436 if ((num = getnum(&regs[RT2][2])) <= 0 || num > 63) goto std;
437 if (num == 1)
438 {
439 p->op = INC; regs[RT2][0] = '\0';
440 }
441 else
442 {
443 register char *t;
444
445 t=regs[RT1];regs[RT1]=regs[RT2];regs[RT2]=t;
446 p->op = ADD; p->subop = U(p->subop, OP2);
447 for (t = &regs[RT1][2]; t[-1] = *t; t++) ;
448 }
449 p->pop = 0; newcode(p);
450 goto std;
451 }
452
453 case JBR: case JMP:
454 clearuse();
455 if ((p->subop&0xF)==RET) {
456 switch((p->subop>>4)&0xF) {
457 case 2: uses[1]=p; regs[1][0]= -1;
458 case 1: uses[0]=p; regs[0][0]= -1;
459 }
460 break;
461 }
462 if (p->ref==0) goto std; /* jmp (r0) */
463 /* fall through */
464 case CBR:
465 if (p->ref->ref!=0) {
466 for (r=NUSE;--r>=0;)
467 if ((1<<r) & (int)p->ref->ref) {uses[r]=p; regs[r][0]= -1;}
468 if ((1<<NUSE) & (int)p->ref->ref) useacc=p;
469 }
470 break;
471 case LNF:
472 /* lnf a; addf b ==> ldf b; subf a */
473 { register struct node *pf = p->forw;
474 if(pf->op==ADDF && p->subop==pf->subop) {
475 p->op = LDF;
476 p->pop = 0;
477 pf->op = SUBF;
478 pf->pop = 0;
479 cp1 = p->code;
480 p->code = pf->code;
481 pf->code = cp1;
482 p = pf->forw;
483 break;
484 }}
485 case LDF: case LDFD: case CVLF: /* destroy acc */
486 useacc = 0;
487 goto std;
488 case STF:
489 { register struct node *pf;
490 if((pf=flops(p)) != p) {
491 p = pf; /* usually p->forw; */
492 break;
493 }}
494 if(ldmov(p)) {
495 p = p->forw;
496 break;
497 }
498 if(useacc == 0)
499 useacc = p;
500 goto std;
501 case ADDF: case MULF: /* commutatives - create clients for flops */
502 /* stf a; ldf b; addf a => stf a; ldf a; addf b */
503 { register struct node *pb = p->back;
504 register struct node *pbb = pb->back;
505 if(pb->op==LDF && pb->subop==p->subop &&
506 pbb && pbb->op==STF && pbb->subop==p->subop &&
507 equstr(pbb->code, p->code)) {
508 cp1 = p->code;
509 p->code = pb->code;
510 pb->code = cp1;
511 }}
512 /* use acc and regs */
513 case CMPF: case CVFL: case SUBF: case DIVF:
514 if(useacc == 0)
515 useacc = p;
516 goto std;
e6c8f4f3
SL		 517 case TSTF:
518 break;
519 case PUSHD:
3347ccab
SL		 520 if(ldmov(p)) {
521 p = p->forw;
522 break;
523 }
524 case CVDF: case NEGF: /* use only acc */
525 case SINF: case COSF: case ATANF: case LOGF: case SQRTF: case EXPF:
526 if(useacc == 0)
527 useacc = p;
528 case EROU: case JSW:
529 case TEXT: case DATA: case BSS: case ALIGN: case WGEN: case END: ;
530 }
531 }
532 for (p= &first; p!=0; p=p->forw)
533 if (p->op==LABEL || p->op==DLABEL) p->ref=0; /* erase our tracks */
534}
535
536char *
537byondrd(p) register struct node *p; {
538/* return pointer to register which is "beyond last read/modify operand" */
864f1f35 539 if (has2ops(p)) return(regs[RT3]);
3347ccab
SL		 540 switch (p->op) {
541 case MFPR:
542 case PUSHA:
543 case TST: case INC: case DEC: case PUSH:
544 case LDF: case LNF: case CVLF: case LDFD:
545 case ADDF: case SUBF: case MULF: case DIVF:
546 case CMPF:
547 return(regs[RT2]);
548 case MTPR:
549#ifndef EMOD
550 case EDIV:
551#endif EMOD
552 case CBR: /* must be JBC/JBS */
553 case BIT: case CMP: case CALLS: case CALLF:
554 case CMPF2:
555 return(regs[RT3]);
556 case EMUL:
557 case PROBE:
558 case MOVBLK:
559 case CASE:
560 return(regs[RT4]);
561 }
562 return(lastrand);
563}
564
565struct node *
566bflow(p)
864f1f35 567 register struct node *p;
3347ccab
SL		 568{
569 register char *cp1,*cp2,**preg;
570 register int r, fr, dblflg=0;
571 int flow= -1;
572 struct node *olduse=0, *olduse1=0;
573
e22e545c
DS		 574 if (p->subop==QUAD || p->subop==DOUBLE || (p->subop&0xF0)==DOUBLE<<4 ||
575 p->op==EMUL)
3347ccab 576 dblflg |= 1; /* double dest */
864f1f35 577 if ((p->subop&0xF)==DOUBLE || p->subop==QUAD)
3347ccab
SL		 578 dblflg |= 2; /* double src */
579 splitrand(p);
864f1f35 580 if (p->op!=PUSH &&
3347ccab 581#ifndef EMOD
864f1f35 582 p->op!=EDIV &&
3347ccab 583#endif EMOD
864f1f35
SL		 584 p->op!=EMUL &&
585 p->subop && tempreg(lastrand,r) && uses[r]==p->forw) {
586 if (equtype(p->subop,regs[r][0]) ||
587 ((p->op==CVT || p->op==MOVZ || p->op==CVFL) &&
588 (regs[r][0]&0xf) && compat((p->subop>>4)&0xf,regs[r][0])) ||
589 p->op==MOVA && compat(LONG, regs[r][0])) {
3347ccab 590 register int r2;
864f1f35
SL		 591
592 if (regs[r][1]!=0) { /* send directly to destination */
3347ccab 593 if (p->op==INC || p->op==DEC) {
864f1f35
SL		 594 p->op = (p->op==DEC) ? SUB : ADD;
595 /* use 2 now, convert to 3 later */
596 p->subop=(OP2<<4)+(p->subop&0xF);
3347ccab 597 p->pop=0;
864f1f35
SL		 598 cp1=lastrand; cp2=regs[RT2];
599 while (*cp2++= *cp1++) /* copy reg */
600 ;
3347ccab
SL		 601 cp1=lastrand; *cp1++='$'; *cp1++='1'; *cp1=0;
602 }
603 cp1=regs[r]+1; cp2=lastrand;
864f1f35
SL		 604 if (has2ops(p)) {
605 /* use 3 operand form of instruction */
3347ccab 606 p->pop=0;
864f1f35
SL		 607 p->subop += (OP3-OP2)<<4;
608 lastrand = cp2 = regs[RT3];
3347ccab 609 }
864f1f35
SL		 610 while (*cp2++= *cp1++)
611 ;
3347ccab
SL		 612 if (p->op==MOVA && p->forw->op==PUSH) {
613 p->op=PUSHA;
614 *regs[RT2]=0; p->pop=0;
864f1f35
SL		 615 } else if ((p->op==MOV || p->op==CVT) &&
616 p->forw->op==PUSH) {
3347ccab
SL		 617 p->op=PUSH; p->subop &= 0xF;
618 *regs[RT2]=0; p->pop=0;
619 }
620 delnode(p->forw);
864f1f35
SL		 621 if (tempreg(lastrand,r2))
622 uses[r2]=uses[r], uses[r]=0;
3347ccab
SL		 623 redun3(p);
624 newcode(p); redunm++; flow=r;
864f1f35 625 } else if (p->op==MOV) { /* superfluous fetch */
3347ccab
SL		 626 int nmatch;
627 char src[C2_ASIZE];
628 movit:
864f1f35
SL		 629 for (cp2=src, cp1=regs[RT1]; *cp2++= *cp1++;)
630 ;
3347ccab
SL		 631 splitrand(p->forw);
632 if (p->forw->op != INC && p->forw->op != DEC)
633 lastrand=byondrd(p->forw);
634 nmatch=0;
635 for (preg=regs+RT1;*preg!=lastrand;preg++)
636 if (r==isreg(*preg)) {
864f1f35
SL		 637 cp2= *preg; cp1=src;
638 while (*cp2++= *cp1++)
639 ;
640 ++nmatch;
3347ccab
SL		 641 }
642 if (nmatch==1) {
864f1f35 643 if (has2ops(p->forw) && equstr(src,regs[RT2])) {
3347ccab 644 p->forw->pop=0;
864f1f35
SL		 645 p->forw->subop += (OP3-OP2)<<4;
646 cp1=regs[RT3];
647 *cp1++ = 'r'; *cp1++ = r+'0'; *cp1=0;
3347ccab 648 }
864f1f35
SL		 649 delnode(p);
650 p=p->forw;
651 if (tempreg(src,r2))
652 uses[r2]=uses[r], uses[r]=0;
3347ccab 653 redun3(p);
e0921d75
DS		 654 newcode(p); redunm++;
655 return(p); /* avoid stale uses[] data */
864f1f35
SL		 656 } else
657 splitrand(p);
3347ccab 658 }
864f1f35
SL		 659 } else if (p->op==MOV && (p->forw->op==CVT || p->forw->op==MOVZ) &&
660 p->forw->subop&0xf && /* if base or index, then forget it */
661 compat(p->subop,p->forw->subop) && !indexa(cp1=regs[RT1]))
662 goto movit;
3347ccab
SL		 663 }
664 /* adjust 'lastrand' past any 'read' or 'modify' operands. */
665 lastrand=byondrd(p);
666 /* a 'write' clobbers the register. */
864f1f35
SL		 667 if (tempreg(lastrand,r) ||
668 (has2ops(p) && tempreg(regs[RT2],r) && uses[r]==0)) {
669 /*
670 * Writing a dead register is useless,
671 * but watch side effects
672 */
3347ccab
SL		 673 switch (p->op) {
674#ifndef EMOD
675 case EDIV:
676#endif EMOD
864f1f35
SL		 677 case AOBLEQ: case AOBLSS:
678 break;
3347ccab 679 default:
864f1f35
SL		 680 /*
681 * If no direct uses, check for
682 * use of condition codes
683 */
3347ccab 684 if (uses[r]==0 && ((dblflg&1)==0 || uses[r+1]==0)) {
864f1f35
SL		 685 register struct node *q = p;
686
687 while ((q = nonlab(q->forw))->op==JBR &&
688 q->subop==0)
689 q=q->ref; /* cc unused, unchanged */
690 if (q->op!=CBR && q->op!=ADDA && q->op!=SUBA) {
691 /* ... and destroyed */
3347ccab 692 preg=regs+RT1;
864f1f35
SL		 693 while (cp1 = *preg++) {
694 if (cp1==lastrand &&
695 p->op != CLR &&
696 p->op != CVFL) {
697 redunm++;
698 delnode(p);
699 return(p->forw);
700 }
701 if (equstr(cp1,lastrand))
702 break;
3347ccab
SL		 703 }
704 }
705 }
706 flow=r;
707 }
708 }
864f1f35
SL		 709 if ((r=flow) >= 0) {
710 olduse=uses[r], uses[r]=0;
711 *(short *)(regs[r])=0;
3347ccab 712 /* if r0 destroyed, dont keep r1 */
864f1f35
SL		 713 if (dblflg&1) {
714 olduse1=uses[++r], uses[r]=0;
715 *(short *)(regs[r])=0;
3347ccab
SL		 716 }
717 }
718 /* now look for 'read' or 'modify' (read & write) uses */
719 preg=regs+RT1;
720 while (*(cp1= *preg++)) {
721 /* check for r */
6e32ca3e
DS		 722 if (lastrand!=cp1 && tempreg(cp1,r)) {
723 int isunused;
724 if (isunused=(uses[r]==0)) {
725 uses[r]=p;
726 cp2=regs[r]; *cp2++=p->subop;
727 if ((p->op==SHAL || p->op==SHAR ||
728 p->op==SHL || p->op==SHR) &&
729 cp1==regs[RT1])
730 cp2[-1] = BYTE;
731 if (p->op==CBR && (p->subop==JBC || p->subop==JBS))
732 cp2[-1] = LONG;
733 if (p->op==MOVA && cp1==regs[RT2])
734 cp2[-1]=LONG;
735 }
3347ccab 736 /* ediv/emod's 2nd operand is quad */
864f1f35 737 if (((p->op==EDIV
3347ccab 738#ifdef EMOD
864f1f35 739 || p->op==EMOD
3347ccab 740#endif EMOD
864f1f35
SL		 741 ) && cp1==regs[RT2] || (dblflg&2)) &&
742 ++r<NUSE && uses[r]==0) {
6e32ca3e
DS		 743 if (isunused)
744 *cp2=0;
864f1f35
SL		 745 uses[r]=p;
746 cp2=regs[r]; *cp2++=p->subop;
6e32ca3e
DS		 747 if (!isunused)
748 *cp2=0;
3347ccab 749 }
6e32ca3e
DS		 750 if (!isunused)
751 continue;
864f1f35
SL		 752 if (p->op==MOV || p->op==PUSH || p->op==CVT ||
753 p->op==MOVZ || p->op==COM || p->op==NEG ||
754 p->op==STF) {
755 if (p->op!=PUSH) {
3347ccab 756 cp1=regs[RT2];
864f1f35
SL		 757 if (tempreg(cp1,r)) {
758 /*
759 * reincarnation!!
760 * (as in addl2 r0,r1;
761 * movl r1,r0; ret)
762 */
763 if (uses[r]==0)
3347ccab 764 uses[r]=olduse;
864f1f35 765 if ((dblflg&1) && uses[r+1]==0)
3347ccab
SL		 766 uses[r+1]=olduse1;
767 }
864f1f35
SL		 768 if (p->op!=MOV)
769 cp1=0;
770 } else
771 cp1="-(sp)";
772 if (cp1)
773 while (*cp2++= *cp1++)
774 ;
775 else
776 *cp2=0;
777 } else
778 *cp2=0;
3347ccab
SL		 779 continue;
780 }
781 /* check for (r),[r] */
864f1f35
SL		 782 do {
783 if (*cp1=='(' || *cp1=='[') { /* get register number */
784 char t;
785 for (cp2= ++cp1; *++cp1!=')' && *cp1!=']';)
786 ;
787 t= *cp1; *cp1=0;
788 if (tempreg(cp2,r) &&
789 (uses[r]==0 || uses[r]==p)) {
790 uses[r]=p;
791 regs[r][0] =
792 (*--cp2=='[' ? OPX<<4 : OPB<<4);
793 }
794 *cp1=t;
3347ccab 795 }
3347ccab
SL		 796 } while (*++cp1);
797 }
798#ifdef MOVAFASTER
799 /* pushax or movax possibility? */
800 cp1=regs[RT1];
801 if (*cp1++=='$' && isstatic(cp1)) {
802 if (p->op==MOV && p->subop==LONG) {
803 if (regs[RT1][1]=='L' && 0!=(p->labno=getnum(regs[RT1]+2))) {
804 cp1=p->code; while (*cp1++!=','); p->code= --cp1;
805 }
806 p->op = MOVA; p->subop = BYTE; ++p->code; p->pop=0;
807 } else if (p->op==PUSH && p->subop==LONG) {
808 p->op = PUSHA; p->subop = BYTE; ++p->code; p->pop=0;
809 } else if (p->op==ADD && p->subop==U(LONG,OP3)
810 && 0<=(r=isreg(regs[RT2]))) {
811 cp1=cp2=p->code; ++cp1;
812 do *cp2++= *cp1; while (*cp1++!=','); cp2[-1]='[';
813 do *cp2++= *cp1; while (*cp1++!=','); cp2[-1]=']';
814 if (!equstr(regs[RT3],"-(sp)")){ p->op = MOVA; p->subop = BYTE;}
815 else {p->op = PUSHA; p->subop = BYTE; *cp2=0;}
816 if (uses[r]==0) {uses[r]=p; regs[r][0]=OPX<<4;}
817 p->pop=0;
818 }
819 }
820#endif MOVAFASTER
864f1f35 821 return (p);
3347ccab
SL		 822}
823
824/* try to eliminate STF's */
825struct node *
826flops(q)
827register struct node *q;
828{
829 register struct node *p;
830 register int r;
831
864f1f35 832 if(q->op!=STF || !tempreg(q->code,r))
3347ccab
SL		 833 return(q);
834 if(uses[r]) {
835 /* see if anyone destroys acc between us */
836 for(p=q->forw; p!=uses[r]; p=p->forw)
837 switch(p->op) {
838 case LABEL:
839 case LDF: case LNF: case CVLF: case LDFD:
840 case CVDF: case NEGF: case ADDF: case SUBF:
841 case MULF: case DIVF: case SINF: case COSF:
842 case ATANF: case LOGF: case SQRTF: case EXPF:
843 return(q);
844 }
845
846 if(q->subop == p->subop)
847 switch(p->op) { /* do it in the accumulator */
848 case LDF: /* redundant load */
849 delnode(p); nld++;
850 p = p->forw;
851 break;
852 case LNF: /* stf r; lnf r ==> negf */
853 p->op = NEGF;
854 p->pop = 0;
855 p->code = 0;
856 break;
857 case CMPF2: /* stf r; cmpf2 r,x ==> cmpf x */
858 { register char *s;
859 register struct node *p1=p->forw;
860 for(s=p->code; *s!=','; s++);
861 *s = 0;
862 if(isreg(p->code) == r)
863 p->code = s+1;
864 else {
865 if(p1->op != CBR || isreg(s+1) != r) {
866 *s = ',';
867 return(q);
868 }
869 if(p1->subop > JNE) {
870 p1->subop ^= 1;
871 p1->pop = 0;
872 nrevbr++;
873 }
874 }
875 p->op = CMPF;
876 p->pop = 0;
877 }
878 break;
879 default:
880 return(q);
881 }
882 else if(p->subop==LONG) {
883 switch(p->op) {
884 case TST: /* stf r; tstl r ==> tstf */
885 p->op = TSTF;
886 p->code = 0;
887 break;
888 /* send directly to destination */
889 case MOV: /* stf r; movl r,x ==> stf x */
890 case PUSH: /* stf r; pushl r ==> stf -(sp)/pushd */
891 if(q->subop == DOUBLE) {
892 register struct node *b = p->back;
893 /* assume b's 2nd arg is ok */
894 if(!(b==uses[r+1] && b->op==p->op && b->subop==LONG))
895 return(q);
896 delnode(b); redunm++;
897 }
898 if(p->op==PUSH) {
899 if(q->subop == DOUBLE) {
900 p->op = PUSHD;
901 p->code = 0;
902 } else {
903 p->op = q->op;
904 p->code = copy("-(sp)");
905 }
906 } else {
907 p->op = q->op;
908 while(*p->code++ != ',');
909 }
910 break;
911 default:
912 return(q);
913 }
914 p->pop = 0;
915 p->subop = q->subop;
916 } else
917 return(q);
918 uses[r] = 0;
919 if(q->subop == DOUBLE)
920 uses[r+1] = 0;
921 { /* undo any effect on uses in the area between p and q,
922 * as we are going over it again */
923 register struct node *b;
924 for(b=p; b!=q; b=b->back) {
925 for(r=0; r<NUSE; r++) {
926 if(uses[r] == b)
927 uses[r] = 0;
928 if(useacc == b)
929 useacc = 0;
930 }
931 }
932 }
933 return(p->forw); /* make p the next for bflow */
934 }
935 /* it's a store to reg which isnt used elsewhere */
936 if((p=q->forw)->op == CBR) {
937 q->op = TSTF;
938 q->pop = 0;
939 q->code = 0;
940 } else {
941 delnode(q); nst++;
942 if(p->op ==STF || p->op==TSTF || p->op==PUSHD) {
943 if(useacc == p)
944 useacc = 0;
945 return(p->forw); /* so ldmov can be used on p */
946 }
947 }
948 return(p);
949}
950
951/* try to change load/store sequences to movl */
952ldmov(q)
953register struct node *q;
954{
955 register struct node *p;
956 register char *s, *pcod, *cp;
957 char *dlsw();
958
959 p = q->back;
960 if(!(useacc==0 && (q->op==STF || q->op==TSTF || q->op==PUSHD)
961 && ((p->op==LDF && p->subop==q->subop) || (p->op==LDFD && q->subop==DOUBLE))))
962 return(0);
963 pcod = p->code;
964 cp = p->code;
965 /* prepare args for movl/pushl */
966 if(q->op!=TSTF && q->subop==DOUBLE) {
967 if(p->op == LDF) {
968 if((s = dlsw(p->code)) == NULL)
969 return(0);
e6c8f4f3 970
3347ccab
SL		 971 strcpy(line, s);
972 if(q->op == STF) {
973 strcat(line, ",");
974 if((s = dlsw(q->code)) == NULL)
975 return(0);
976 strcat(line, s);
977 p->op = MOV;
978 } else
979 p->op = PUSH;
980 } else { /* LDFD */
981 if(q->op == STF) {
982 if((s = dlsw(q->code)) == NULL)
983 return(0);
984 } else
985 s = "-(sp)";
986 strcpy(line, s);
987 p->op = CLR;
988 }
989 p->pop = 0;
990 p->subop = LONG;
991 p->code = copy(line);
992 } else
993 {
994 if ((p->op == LDF) && (p->subop == DOUBLE) &&
995 (indexa(cp))) return(0);
996 delnode(p);
997 }
998 strcpy(line, pcod);
999 if(q->op == STF) { /* ldf x; stf y ==> movl x,y */
1000 strcat(line, ",");
1001 strcat(line, q->code);
1002 q->op = MOV;
1003 nst++;
1004 } else if(q->op == TSTF) /* ldf x; tstf ==> tstl x */
1005 q->op = TST;
1006 else /* ldd x; pushd ==> pushl x+4; pushl x */
1007 q->op = PUSH;
1008 q->pop = 0;
1009 q->subop = LONG;
1010 q->code = copy(line);
1011 nld++;
1012 return(1);
1013}
1014
1015/* reconstruct the address of l.s.w. of a double operand */
1016char *
1017dlsw(d)
1018 register char *d;
1019{
e6c8f4f3 1020 register char *s, *t, *c;
3347ccab
SL		 1021 register int r;
1022 static char lsw[C2_ASIZE];
1023
1024 if(d[0] == '*' || d[0] == '$')
1025 return(NULL);
e6c8f4f3
SL		 1026 if (((strncmp(d, "(r", 2)) == 0) && isdigit(d[2]))
1027 return(NULL);
3347ccab
SL		 1028 t = lsw;
1029 if((r=isreg(d)) >= 0)
1030 sprintf(t, "r%d", r+1);
1031 else {
1032 for(s=d; *s && *s!='('; *t++ = *s++)
1033 if(*s == '[')
1034 return(NULL);
e6c8f4f3
SL		 1035 if(s!=d)
1036 *t++ = '+';
1037 *t++ = '4';
3347ccab 1038 while(*t++ = *s)
e6c8f4f3
SL		 1039 if(*s++ == '[' )
1040 {
3347ccab 1041 return(NULL);
e6c8f4f3 1042 }
3347ccab
SL		 1043 }
1044 return(lsw);
1045}
e6c8f4f3
SL		 1046checkexpr(p)
1047register char *p;
1048{
1049
1050 while(*p && *p != ','){
1051 if ((*p == '+' ) || (*p == '-'))
1052 return(1);
1053 *p++;
1054 }
1055 return(0);
1056}
Continuous source code history from original PDP-7 UNIX to FreeBSD 2, the first fully unencumbered FreeBSD release.