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Up to [Power 6/32 Unix Tahoe 4.2BSD] / cci / usr / src / lib / fc2|
Return to c21.c CVS log | Up to [Power 6/32 Unix Tahoe 4.2BSD] / cci / usr / src / lib / fc2 |
1.1 root 1: /*
2: * C object code improver-- second part
3: */
4:
5: #include "c2.h"
6: #include <stdio.h>
7: #include <ctype.h>
8:
9: int bitsize[] = {0,8,16,32,64,32,64}; /* index by type codes */
10:
11: redun3(p) register struct node *p; {
12: /* check for 3 addr instr which should be 2 addr */
13: if (OP3==((p->subop>>4)&0xF)) {
14: if (equstr(regs[RT1],regs[RT3])
15: && (p->op==ADD || p->op==MUL || p->op==AND || p->op==OR || p->op==XOR)) {
16: register char *t=regs[RT1]; regs[RT1]=regs[RT2]; regs[RT2]=t;
17: }
18: if (equstr(regs[RT2],regs[RT3])) {
19: p->subop=(p->subop&0xF)|(OP2<<4); p->pop=0;
20: lastrand=regs[RT2]; *regs[RT3]=0; return(1);
21: }
22: } return(0);
23: }
24:
25: bmove() {
26: register struct node *p, *lastp; register char *cp1,*cp2; register int r;
27: struct node *flops();
28:
29: refcount();
30: for (p=lastp= &first; 0!=(p=p->forw); lastp=p);
31: clearreg(); clearuse();
32: for (p=lastp; p!= &first; p=p->back) {
33: if (debug) {
34: printf("Uses: ");
35: if (useacc)
36: printf("acc: %s\n",useacc->code? useacc->code:"");
37: for (r=NUSE;--r>=0;) if (uses[r])
38: printf("%d: %s\n",r,uses[r]->code? uses[r]->code:"");
39: printf("-\n");
40: }
41: r=(p->subop>>4)&0xF;
42: splitrand(p);
43: if (OP3==r && 0!=redun3(p)) {newcode(p); redunm++;}
44: /* ops that do nothing */
45: if(p->op==MOV && equstr(regs[RT1], regs[RT2]))
46: if(p->forw->op!=CBR) {
47: delnode(p); redunm++; continue;
48: } else {
49: p->op=TST; p->pop=0;
50: while(*p->code++ != ',');
51: redunm++;
52: }
53: else if((cp1=p->code, *cp1++)=='$' &&
54: (*cp1=='0' || *cp1=='1' || *cp1++=='-' && *cp1=='1') && cp1[1]==',') {
55: switch((p->code[1]<<8)|p->op) {
56: case (('0'<<8)|ADD):
57: case (('0'<<8)|SUB):
58: case (('-'<<8)|AND):
59: case (('0'<<8)|OR):
60: case (('0'<<8)|XOR):
61: case (('1'<<8)|MUL):
62: case (('1'<<8)|DIV):
63: case (('0'<<8)|SHAL):
64: case (('0'<<8)|SHAR):
65: case (('0'<<8)|SHL):
66: case (('0'<<8)|SHR):
67: if(r == OP2) {
68: if(p->forw->op!=CBR) {
69: delnode(p); redunm++; continue;
70: } else {
71: p->op=TST; p->subop&=0xF; p->pop=0;
72: while(*p->code++ != ',');
73: redunm++;
74: }
75: } else { /* OP3 or shift */
76: p->op=MOV; p->subop&=0xF; p->pop=0;
77: while(*p->code++ != ',');
78: p = p->forw; redunm++; continue;
79: }
80: break;
81: case (('0'<<8)|MUL):
82: case (('0'<<8)|AND):
83: p->op=CLR; p->subop&=0xF; p->pop=0;
84: while(*p->code++ != ',');
85: if(r == OP3)
86: while(*p->code++ != ',');
87: redunm++;
88: }
89: }
90: switch (p->op) {
91: case LABEL: case DLABEL:
92: for (r=NUSE; --r>=0;)
93: if (uses[r]) p->ref=(struct node *) (((int)p->ref)|(1<<r));
94: if (useacc) p->ref=(struct node *) (((int)p->ref)|(1<<NUSE));
95: break;
96: case CALLS:
97: case CALLF:
98: clearuse(); goto std;
99: case 0:
100: clearuse(); break;
101: case CVT:
102: { long n;
103: if ((p->subop&0xF)!=LONG) goto std; cp1=p->code;
104: if (*cp1++!='$') goto std; splitrand(p);
105: n = getnum(®s[RT1][1]);
106: if(r==BYTE && (n<-128 || n>127)) goto std;
107: if(r==WORD && (n<-32768 || n>32767)) goto std;
108: p->op = MOV; p->subop = r; p->pop = 0;
109: } goto std;
110:
111: case SUB:
112: if ((p->subop&0xF)!=LONG) goto std; cp1=p->code;
113: if (*cp1++!='$') goto std; splitrand(p);
114: #ifdef MOVAFASTER
115: if (equstr(regs[RT2],"fp") && !indexa(regs[RT1])) {/* address comp. */
116: char buf[C2_ASIZE]; cp2=buf; *cp2++='-';
117: cp1=regs[RT1]+1; while (*cp2++= *cp1++); --cp2;
118: cp1="(fp),"; while (*cp2++= *cp1++); --cp2;
119: cp1=regs[RT3]; while (*cp2++= *cp1++);
120: p->code=copy(buf); p->op = MOVA; p->subop = BYTE; p->pop=0;
121: } else
122: #endif MOVAFASTER
123: if (*cp1++=='-' && 0<=(r=getnum(cp1))) {
124: p->op=ADD; p->pop=0; *--cp1='$'; p->code=cp1;
125: } goto std;
126: case ADD:
127: if ((p->subop&0xF)!=LONG) goto std; cp1=p->code;
128: if (*cp1++!='$') goto std; splitrand(p);
129: if (isstatic(cp1) && (r=isreg(regs[RT2]))>=0 && r<NUSE && uses[r]==p->forw)
130: {
131: /* address comp:
132: ** addl2 $_foo,r0 \ movab _foo[r0],bar
133: ** movl r0,bar /
134: */
135: register struct node *pnext = p->forw;
136: char buf[C2_ASIZE];
137:
138: if (pnext->op == MOV && pnext->subop == LONG)
139: {
140: cp1 = ®s[RT1][1]; cp2 = &buf[0];
141: while (*cp2++ = *cp1++) ; cp2--;
142: splitrand(pnext);
143: if (r == isreg(regs[RT1]))
144: {
145: delnode(p); p = pnext;
146: p->op = MOVA; p->subop = BYTE;
147: p->pop = 0;
148: cp1 = regs[RT1]; *cp2++ = '[';
149: while (*cp2++ = *cp1++) ; cp2--;
150: *cp2++ = ']'; *cp2++ = ',';
151: cp1 = regs[RT2];
152: while (*cp2++ = *cp1++) ;
153: p->code = copy(buf);
154: }
155: }
156: }
157: else
158: #ifdef MOVAFASTER
159: if (equstr(regs[RT2],"fp") && !indexa(regs[RT1])) {/* address comp. */
160: cp2=cp1-1; cp1=regs[RT1]+1; while (*cp2++= *cp1++); --cp2;
161: cp1="(fp)"; while (*cp2++= *cp1++); *--cp2=',';
162: p->op = MOVA; p->subop = BYTE; p->pop=0;
163: } else
164: #endif MOVAFASTER
165: if (*cp1++=='-' && 0<=(r=getnum(cp1))) {
166: p->op=SUB; p->pop=0; *--cp1='$'; p->code=cp1;
167: }
168: /* fall thru ... */
169: case CASE:
170: default: std:
171: p=bflow(p); break;
172:
173: case MUL:
174: /*
175: ** Change multiplication
176: ** by constant powers of 2 to shifts.
177: */
178: splitrand(p);
179: if (regs[RT1][0] != '$' || regs[RT1][1] == '-') goto std;
180: if ((r = ispow2(getnum(®s[RT1][1]))) <= 0) goto std;
181: /* mull2 $2,x */
182: if(r == 1 && p->subop == U(LONG, OP2)) {
183: strcpy(regs[RT1], regs[RT2]);
184: p->op = ADD; p->pop = 0; newcode(p);
185: goto std;
186: }
187: if (p->subop == U(LONG,OP2))
188: strcpy(regs[RT3], regs[RT2]);
189: sprintf(regs[RT1], "$%d", r);
190: p->op = SHL; p->subop = LONG;
191: p->pop = 0; newcode(p);
192: goto std;
193:
194: case SHAL:
195: case SHL:
196: {
197: /* bit tests:
198: ** shll A,$1,rC \
199: ** bitl B,rC > jbc A,B,D
200: ** jeql D /
201: **
202: ** address comp:
203: ** shll $1,bar,r0 \ movl bar,r0
204: ** movab _foo[r0] / movaw _foo[r0]
205: **
206: ** shll $2,r0,r0 \ moval _foo[r0]
207: ** movab _foo[r0] /
208: */
209: register struct node *pf;
210: register struct node *pn;
211: register int shfrom, shto;
212: long shcnt;
213: char *regfrom;
214:
215: splitrand(p);
216: if (regs[RT1][0] != '$') {
217: if(isreg(regs[RT1]) < 0) goto std; /* alignment */
218: if (regs[RT2][0] != '$') goto std;
219: if (getnum(®s[RT2][1]) != 1) goto std;
220: r = isreg(regs[RT3]);
221: if (r < 0 || r >= NUSE) goto std;
222: if ((pf = p->forw)->op != BIT && pf->op!=AND) goto std;
223: if (uses[r] && uses[r] != pf) goto std;
224: splitrand(pf);
225: if (r == isreg(regs[RT1])) cp2 = regs[RT2];
226: else if (r == isreg(regs[RT2])) cp2 = regs[RT1];
227: else goto std;
228: if (*cp2 == '$') goto std;
229: if ((pn = pf->forw)->op != CBR) goto std;
230: if (pn->subop != JEQ && pn->subop != JNE) goto std;
231: delnode(p); delnode(pf);
232: pn->subop = (pn->subop == JEQ) ? JBC : JBS;
233: for(cp1=p->code; *cp1++!=',';);
234: while (*cp1++= *cp2++);
235: pn->code = p->code; pn->pop = NULL;
236: uses[r] = NULL;
237: nbj++;
238: p = pn;
239: goto std;
240: }
241: if ((shcnt = getnum(®s[RT1][1])) < 1 || shcnt > 2) goto std;
242: if ((shfrom = isreg(regs[RT2])) >= 0)
243: regfrom = copy(regs[RT2]);
244: if ((shto = isreg(regs[RT3])) >= 0 && shto<NUSE)
245: {
246: int regnum;
247:
248: if (uses[shto] != (pf = p->forw)) goto ashadd;
249: if (pf->op != MOVA && pf->op != PUSHA) goto ashadd;
250: if (pf->subop != BYTE) goto ashadd;
251: splitrand(pf);
252: if (!indexa(regs[RT1])) goto std;
253: cp2 = regs[RT1];
254: if(!isstatic(cp2)) goto std;
255: while (*cp2++ != '[') ;
256: if (*cp2++ != 'r' || !isdigit(*cp2)) goto std;
257: regnum = *cp2++ - '0';
258: if (isdigit(*cp2))
259: {
260: if (cp2[1] != ']') goto std;
261: regnum *= 10; regnum += *cp2 - '0';
262: }
263: if (regnum != shto) goto std;
264: if (shfrom >= 0) /* shll $N,r*,r0 */
265: {
266: delnode(p);
267: p = pf;
268: if (shfrom != shto)
269: {
270: uses[shto] = NULL; splitrand(pf);
271: cp2=regs[RT1]; while (*cp2++!='[');
272: cp1=regfrom; while (*cp2++= *cp1++);
273: cp2[-1] = ']'; *cp2 = 0;
274: newcode(pf);
275: }
276: }
277: else
278: {
279: p->op = MOV; splitrand(p);
280: strcpy(regs[RT1], regs[RT2]);
281: strcpy(regs[RT2], regs[RT3]);
282: regs[RT3][0] = '\0';
283: p->pop = 0; newcode(p);
284: }
285: switch (shcnt)
286: {
287: case 1: pf->subop = WORD; break;
288: case 2: pf->subop = LONG; break;
289: }
290: redunm++; nsaddr++;
291: }
292: goto std;
293: ashadd:
294: /* at this point, RT2 and RT3 are guaranteed to be simple regs*/
295: if (shcnt == 1) {
296: /*
297: ** quickie:
298: ** shll $1,A,A > addl2 A,A
299: ** shll $1,A,B > addl3 A,A,B
300: */
301: p->op = ADD;
302: strcpy(regs[RT1], regs[RT2]);
303: if(equstr(regs[RT2], regs[RT3])) {
304: p->subop = U(LONG,OP2);
305: regs[RT3][0] = '\0';
306: } else
307: p->subop = U(LONG,OP3);
308: p->pop = 0;
309: newcode(p);
310: }
311: goto std;
312: }
313:
314: case SHAR:
315: case SHR:
316: {
317: /* bit tests:
318: ** shrl A,B,rC \
319: ** bitl $1,rC > jbc A,B,D
320: ** jeql D /
321: */
322: register struct node *pf; /* forward node */
323: register struct node *pn; /* next node (after pf) */
324: register int extreg; /* reg extracted to */
325:
326: splitrand(p);
327: if(isreg(regs[RT1]) < 0) goto std; /* alignment */
328: extreg = isreg(regs[RT3]);
329: if (extreg < 0 || extreg >= NUSE) goto std;
330: if ((pf = p->forw)->op != BIT) goto std;
331: if (uses[extreg] && uses[extreg] != pf) goto std;
332: splitrand(pf);
333: if (regs[RT1][0] != '$') goto std;
334: if (getnum(®s[RT1][1]) != 1) goto std;
335: if (extreg != isreg(regs[RT2])) goto std;
336: if ((pn = pf->forw)->op != CBR) goto std;
337: if (pn->subop != JEQ && pn->subop != JNE) goto std;
338: delnode(p); delnode(pf);
339: pn->subop = (pn->subop == JEQ) ? JBC : JBS;
340: for(cp1=p->code; *cp1++!=',';);
341: while (*cp1!=',') cp1++; *cp1='\0';
342: pn->code = p->code; pn->pop = NULL;
343: uses[extreg] = NULL; nbj++;
344: p = pn;
345: goto std;
346: }
347:
348: case AND:
349: {
350: /* unsigned conversion:
351: ** cvtbl A,B; andl2 $255,B > movzbl A,B
352: **
353: ** also byte- and word-size fields:
354: ** shrl $(3-n)*8,A,B; andl2 $255,B > movzbl n+A,B
355: ** shrl $(1-n)*16,A,B; andl2 $65535,B > movzwl n+A,B
356: */
357: char src[C2_ASIZE];
358: register int f; /* field length */
359: register struct node *pb = p->back; /* backward node */
360:
361: if (p->subop != U(LONG,OP2))
362: goto std;
363: splitrand(p); cp1=regs[RT1];
364: if (*cp1++!='$' || (f=getnum(cp1))!=0xff && f!=0xffff)
365: goto std;
366: f = f==0xff ? 8 : 16;
367: if (pb->op!=CVT && pb->op!=MOVZ && pb->op!=SHAR && pb->op!=SHR)
368: goto std;
369: /* save source of ANDL in 'src' */
370: strcpy(src, regs[RT2]);
371: splitrand(pb);
372: if (!equstr(src,lastrand))
373: goto std;
374: if (pb->op==CVT || pb->op==MOVZ) {
375: if (!(bitsize[pb->subop&0xF]==f
376: && bitsize[pb->subop>>4]>=f)) /* good CVT */
377: goto std;
378: strcpy(src, regs[RT1]);
379: } else {
380: register int boff; /* bit offset */
381:
382: if (regs[RT1][0] != '$') goto std;
383: if ((boff = getnum(®s[RT1][1])) < 0) goto std;
384: if (isreg(regs[RT2])>=0 || !natural(regs[RT2])) goto std;
385: if ((boff & (f-1)) != 0) goto std;
386: boff = (32-boff-f) / 8;
387: if (boff == 0)
388: strcpy(src, regs[RT2]);
389: else
390: sprintf(src, "%d%s%s", boff, regs[RT2][0]=='(' ? "":"+",
391: regs[RT2]);
392: }
393: delnode(pb);
394: p->op = MOVZ;
395: p->subop = U((f==8 ? BYTE : WORD), LONG);
396: sprintf(line,"%s,%s",src,lastrand);
397: p->pop=0;
398: p->code = copy(line);
399: goto std;
400: }
401:
402: case CMP:
403: {
404: /* comparison to -63 to -1:
405: ** cmpl r0,$-1 > incl r0
406: ** jeql ...
407: **
408: ** cmpl r0,$-63 > addl2 $63,r0
409: ** jeql ...
410: */
411: register int num;
412: register int reg;
413: register struct node *regp = p->back;
414:
415: if (p->forw->op != CBR) goto std;
416: if (p->forw->subop != JEQ && p->forw->subop != JNE) goto std;
417: splitrand(p);
418: if (strncmp(regs[RT2], "$-", 2) != 0) goto std;
419: reg = r = isreg(regs[RT1]);
420: if (r < 0) goto std;
421: if (r < NUSE && uses[r] != 0) goto std;
422: if (r >= NUSE && regp->op == MOV && p->subop == regp->subop)
423: {
424: if (*regp->code != 'r') goto std;
425: reg = regp->code[1] - '0';
426: if (isdigit(regp->code[2]) || reg >= NUSE || uses[reg])
427: goto std;
428: }
429: if (r >= NUSE) goto std;
430: if (reg != r)
431: sprintf(regs[RT1], "r%d", reg);
432: if ((num = getnum(®s[RT2][2])) <= 0 || num > 63) goto std;
433: if (num == 1)
434: {
435: p->op = INC; regs[RT2][0] = '\0';
436: }
437: else
438: {
439: register char *t;
440:
441: t=regs[RT1];regs[RT1]=regs[RT2];regs[RT2]=t;
442: p->op = ADD; p->subop = U(p->subop, OP2);
443: for (t = ®s[RT1][2]; t[-1] = *t; t++) ;
444: }
445: p->pop = 0; newcode(p);
446: goto std;
447: }
448:
449: case JBR: case JMP:
450: clearuse();
451: if ((p->subop&0xF)==RET) {
452: switch((p->subop>>4)&0xF) {
453: case 2: uses[1]=p; regs[1][0]= -1;
454: case 1: uses[0]=p; regs[0][0]= -1;
455: }
456: break;
457: }
458: if (p->ref==0) goto std; /* jmp (r0) */
459: /* fall through */
460: case CBR:
461: if (p->ref->ref!=0) {
462: for (r=NUSE;--r>=0;)
463: if ((1<<r) & (int)p->ref->ref) {uses[r]=p; regs[r][0]= -1;}
464: if ((1<<NUSE) & (int)p->ref->ref) useacc=p;
465: }
466: break;
467: case LNF:
468: /* lnf a; addf b ==> ldf b; subf a */
469: { register struct node *pf = p->forw;
470: if(pf->op==ADDF && p->subop==pf->subop) {
471: p->op = LDF;
472: p->pop = 0;
473: pf->op = SUBF;
474: pf->pop = 0;
475: cp1 = p->code;
476: p->code = pf->code;
477: pf->code = cp1;
478: p = pf->forw;
479: break;
480: }}
481: case LDF: case LDFD: case CVLF: /* destroy acc */
482: useacc = 0;
483: goto std;
484: case STF:
485: { register struct node *pf;
486: if((pf=flops(p)) != p) {
487: p = pf; /* usually p->forw; */
488: break;
489: }}
490: if(ldmov(p)) {
491: p = p->forw;
492: break;
493: }
494: if(useacc == 0)
495: useacc = p;
496: goto std;
497: case ADDF: case MULF: /* commutatives - create clients for flops */
498: /* stf a; ldf b; addf a => stf a; ldf a; addf b */
499: { register struct node *pb = p->back;
500: register struct node *pbb = pb->back;
501: if(pb->op==LDF && pb->subop==p->subop &&
502: pbb && pbb->op==STF && pbb->subop==p->subop &&
503: equstr(pbb->code, p->code)) {
504: cp1 = p->code;
505: p->code = pb->code;
506: pb->code = cp1;
507: }}
508: /* use acc and regs */
509: case CMPF: case CVFL: case SUBF: case DIVF:
510: if(useacc == 0)
511: useacc = p;
512: goto std;
513: case TSTF: case PUSHD:
514: if(ldmov(p)) {
515: p = p->forw;
516: break;
517: }
518: case CVDF: case NEGF: /* use only acc */
519: case SINF: case COSF: case ATANF: case LOGF: case SQRTF: case EXPF:
520: if(useacc == 0)
521: useacc = p;
522: case EROU: case JSW:
523: case TEXT: case DATA: case BSS: case ALIGN: case WGEN: case END: ;
524: }
525: }
526: for (p= &first; p!=0; p=p->forw)
527: if (p->op==LABEL || p->op==DLABEL) p->ref=0; /* erase our tracks */
528: }
529:
530: char *
531: byondrd(p) register struct node *p; {
532: /* return pointer to register which is "beyond last read/modify operand" */
533: if (OP2==(p->subop>>4)) return(regs[RT3]);
534: switch (p->op) {
535: case MFPR:
536: case PUSHA:
537: case TST: case INC: case DEC: case PUSH:
538: case LDF: case LNF: case CVLF: case LDFD:
539: case ADDF: case SUBF: case MULF: case DIVF:
540: case CMPF:
541: return(regs[RT2]);
542: case MTPR:
543: #ifndef EMOD
544: case EDIV:
545: #endif EMOD
546: case CBR: /* must be JBC/JBS */
547: case BIT: case CMP: case CALLS: case CALLF:
548: case CMPF2:
549: return(regs[RT3]);
550: case EMUL:
551: case PROBE:
552: case MOVBLK:
553: case CASE:
554: return(regs[RT4]);
555: }
556: return(lastrand);
557: }
558:
559: struct node *
560: bflow(p)
561: register struct node *p;
562: {
563: register char *cp1,*cp2,**preg;
564: register int r, fr, dblflg=0;
565: int flow= -1;
566: struct node *olduse=0, *olduse1=0;
567:
568: if(p->subop==QUAD || p->subop==DOUBLE || (p->subop&0xF0)==DOUBLE<<4)
569: dblflg |= 1; /* double dest */
570: if((p->subop&0xF)==DOUBLE || p->subop==QUAD)
571: dblflg |= 2; /* double src */
572: splitrand(p);
573: if (p->op!=PUSH
574: #ifndef EMOD
575: && p->op!=EDIV
576: #endif EMOD
577: && p->op!=EMUL
578: && p->subop && 0<=(r=isreg(lastrand)) && r<NUSE && uses[r]==p->forw) {
579: if (equtype(p->subop,regs[r][0])
580: || ((p->op==CVT || p->op==MOVZ || p->op==CVFL)
581: && 0xf®s[r][0] && compat(0xf&(p->subop>>4),regs[r][0]))
582: || p->op==MOVA && compat(LONG, regs[r][0])) {
583: register int r2;
584: if (regs[r][1]!=0) {/* send directly to destination */
585: if (p->op==INC || p->op==DEC) {
586: if (p->op==DEC) p->op=SUB; else p->op=ADD;
587: p->subop=(OP2<<4)+(p->subop&0xF); /* use 2 now, convert to 3 later */
588: p->pop=0;
589: cp1=lastrand; cp2=regs[RT2]; while (*cp2++= *cp1++); /* copy reg */
590: cp1=lastrand; *cp1++='$'; *cp1++='1'; *cp1=0;
591: }
592: cp1=regs[r]+1; cp2=lastrand;
593: if (OP2==(p->subop>>4)) {/* use 3 operand form of instruction */
594: p->pop=0;
595: p->subop += (OP3-OP2)<<4; lastrand=cp2=regs[RT3];
596: }
597: while (*cp2++= *cp1++);
598: if (p->op==MOVA && p->forw->op==PUSH) {
599: p->op=PUSHA;
600: *regs[RT2]=0; p->pop=0;
601: } else if ((p->op==MOV || p->op==CVT) && p->forw->op==PUSH) {
602: p->op=PUSH; p->subop &= 0xF;
603: *regs[RT2]=0; p->pop=0;
604: }
605: delnode(p->forw);
606: if (0<=(r2=isreg(lastrand)) && r2<NUSE) {
607: uses[r2]=uses[r]; uses[r]=0;
608: }
609: redun3(p);
610: newcode(p); redunm++; flow=r;
611: } else if (p->op==MOV) {
612: /* superfluous fetch */
613: int nmatch;
614: char src[C2_ASIZE];
615: movit:
616: cp2=src; cp1=regs[RT1]; while (*cp2++= *cp1++);
617: splitrand(p->forw);
618: if (p->forw->op != INC && p->forw->op != DEC)
619: lastrand=byondrd(p->forw);
620: nmatch=0;
621: for (preg=regs+RT1;*preg!=lastrand;preg++)
622: if (r==isreg(*preg)) {
623: cp2= *preg; cp1=src; while (*cp2++= *cp1++); ++nmatch;
624: }
625: if (nmatch==1) {
626: if (OP2==(p->forw->subop>>4) && equstr(src,regs[RT2])) {
627: p->forw->pop=0;
628: p->forw->subop += (OP3-OP2)<<4; cp1=regs[RT3];
629: *cp1++='r'; *cp1++=r+'0'; *cp1=0;
630: }
631: delnode(p); p=p->forw;
632: if (0<=(r2=isreg(src)) && r2<NUSE) {
633: uses[r2]=uses[r]; uses[r]=0;
634: }
635: redun3(p);
636: newcode(p); redunm++; flow=r;
637: } else splitrand(p);
638: }
639: } else if (p->op==MOV && (p->forw->op==CVT || p->forw->op==MOVZ)
640: && p->forw->subop&0xf /* if base or index, then forget it */
641: && compat(p->subop,p->forw->subop) && !indexa(cp1=regs[RT1]))
642: goto movit;
643: }
644: /* adjust 'lastrand' past any 'read' or 'modify' operands. */
645: lastrand=byondrd(p);
646: /* a 'write' clobbers the register. */
647: if (0<=(r=isreg(lastrand)) && r<NUSE
648: || OP2==(p->subop>>4) && 0<=(r=isreg(regs[RT2])) && r<NUSE && uses[r]==0) {
649: /* writing a dead register is useless, but watch side effects */
650: switch (p->op) {
651: #ifndef EMOD
652: case EDIV:
653: #endif EMOD
654: case EMUL:
655: case AOBLEQ: case AOBLSS: break;
656: default:
657: if (uses[r]==0 && ((dblflg&1)==0 || uses[r+1]==0)) {
658: /* no direct uses, check for use of condition codes */
659: register struct node *q=p;
660: while ((q=nonlab(q->forw))->op==JBR && q->subop==0) q=q->ref; /* cc unused, unchanged */
661: if (q->op!=CBR && q->op!=ADDA && q->op!=SUBA) {/* ... and destroyed */
662: preg=regs+RT1;
663: while (cp1= *preg++) {
664: if ((cp1==lastrand) &&
665: (p->op != CLR) &&
666: (p->op != CVFL))
667: {redunm++; delnode(p); return(p->forw);}
668: if (equstr(cp1,lastrand)) break;
669: }
670: }
671: }
672: flow=r;
673: }
674: }
675: if (0<=(r=flow)) {
676: olduse=uses[r]; uses[r]=0; *(short *)(regs[r])=0;
677: /* if r0 destroyed, dont keep r1 */
678: if(dblflg&1) {
679: olduse1=uses[++r]; uses[r]=0; *(short *)(regs[r])=0;
680: }
681: }
682: /* now look for 'read' or 'modify' (read & write) uses */
683: preg=regs+RT1;
684: while (*(cp1= *preg++)) {
685: /* check for r */
686: if (lastrand!=cp1 && 0<=(r=isreg(cp1)) && r<NUSE && (uses[r]==0)){
687: uses[r]=p; cp2=regs[r]; *cp2++=p->subop;
688: if((p->op==SHAL || p->op==SHAR || p->op==SHL || p->op==SHR)
689: && cp1==regs[RT1]) cp2[-1]=BYTE;
690: if(p->op==CBR && (p->subop==JBC || p->subop==JBS)) cp2[-1]=LONG;
691: if(p->op==MOVA && cp1==regs[RT2]) cp2[-1]=LONG;
692: /* ediv/emod's 2nd operand is quad */
693: if(((p->op==EDIV
694: #ifdef EMOD
695: || p->op==EMOD
696: #endif EMOD
697: ) && cp1==regs[RT2] || (dblflg&2))
698: && ++r<NUSE && uses[r]==0) {
699: *cp2=0;
700: uses[r]=p; cp2=regs[r]; *cp2++=p->subop;
701: }
702: if(p->op==MOV || p->op==PUSH || p->op==CVT ||
703: p->op==MOVZ || p->op==COM || p->op==NEG || p->op==STF) {
704: if (p->op==PUSH) cp1="-(sp)";
705: else {
706: cp1=regs[RT2];
707: if (0<=(r=isreg(cp1)) && r<NUSE) {
708: /* reincarnation!! */
709: /* as in addl2 r0,r1; movl r1,r0; ret */
710: if(uses[r]==0)
711: uses[r]=olduse;
712: if((dblflg&1) && uses[r+1]==0)
713: uses[r+1]=olduse1;
714: }
715: if (p->op!=MOV) cp1=0;
716: }
717: if (cp1) while (*cp2++= *cp1++);
718: else *cp2=0;
719: } else *cp2=0;
720: continue;
721: }
722: /* check for (r),[r] */
723: do if (*cp1=='(' || *cp1=='[') {/* get register number */
724: char t;
725: cp2= ++cp1; while (*++cp1!=')' && *cp1!=']'); t= *cp1; *cp1=0;
726: if (0<=(r=isreg(cp2)) && r<NUSE && (uses[r]==0 || uses[r]==p)) {
727: uses[r]=p; regs[r][0]=(*--cp2=='[' ? OPX<<4 : OPB<<4);
728: }
729: *cp1=t;
730: } while (*++cp1);
731: }
732: #ifdef MOVAFASTER
733: /* pushax or movax possibility? */
734: cp1=regs[RT1];
735: if (*cp1++=='$' && isstatic(cp1)) {
736: if (p->op==MOV && p->subop==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->op = MOVA; p->subop = BYTE; ++p->code; p->pop=0;
741: } else if (p->op==PUSH && p->subop==LONG) {
742: p->op = PUSHA; p->subop = BYTE; ++p->code; p->pop=0;
743: } else if (p->op==ADD && p->subop==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->op = MOVA; p->subop = BYTE;}
749: else {p->op = PUSHA; p->subop = BYTE; *cp2=0;}
750: if (uses[r]==0) {uses[r]=p; regs[r][0]=OPX<<4;}
751: p->pop=0;
752: }
753: }
754: #endif MOVAFASTER
755: return(p);
756: }
757:
758: /* try to eliminate STF's */
759: struct node *
760: flops(q)
761: register struct node *q;
762: {
763: register struct node *p;
764: register int r;
765:
766: if(!(q->op==STF && ((r=isreg(q->code))<NUSE) && r>=0))
767: return(q);
768: if(uses[r]) {
769: /* see if anyone destroys acc between us */
770: for(p=q->forw; p!=uses[r]; p=p->forw)
771: switch(p->op) {
772: case LABEL:
773: case LDF: case LNF: case CVLF: case LDFD:
774: case CVDF: case NEGF: case ADDF: case SUBF:
775: case MULF: case DIVF: case SINF: case COSF:
776: case ATANF: case LOGF: case SQRTF: case EXPF:
777: return(q);
778: }
779:
780: if(q->subop == p->subop)
781: switch(p->op) { /* do it in the accumulator */
782: case LDF: /* redundant load */
783: delnode(p); nld++;
784: p = p->forw;
785: break;
786: case LNF: /* stf r; lnf r ==> negf */
787: p->op = NEGF;
788: p->pop = 0;
789: p->code = 0;
790: break;
791: case CMPF2: /* stf r; cmpf2 r,x ==> cmpf x */
792: { register char *s;
793: register struct node *p1=p->forw;
794: for(s=p->code; *s!=','; s++);
795: *s = 0;
796: if(isreg(p->code) == r)
797: p->code = s+1;
798: else {
799: if(p1->op != CBR || isreg(s+1) != r) {
800: *s = ',';
801: return(q);
802: }
803: if(p1->subop > JNE) {
804: p1->subop ^= 1;
805: p1->pop = 0;
806: nrevbr++;
807: }
808: }
809: p->op = CMPF;
810: p->pop = 0;
811: }
812: break;
813: default:
814: return(q);
815: }
816: else if(p->subop==LONG) {
817: switch(p->op) {
818: case TST: /* stf r; tstl r ==> tstf */
819: p->op = TSTF;
820: p->code = 0;
821: break;
822: /* send directly to destination */
823: case MOV: /* stf r; movl r,x ==> stf x */
824: case PUSH: /* stf r; pushl r ==> stf -(sp)/pushd */
825: if(q->subop == DOUBLE) {
826: register struct node *b = p->back;
827: /* assume b's 2nd arg is ok */
828: if(!(b==uses[r+1] && b->op==p->op && b->subop==LONG))
829: return(q);
830: delnode(b); redunm++;
831: }
832: if(p->op==PUSH) {
833: if(q->subop == DOUBLE) {
834: p->op = PUSHD;
835: p->code = 0;
836: } else {
837: p->op = q->op;
838: p->code = copy("-(sp)");
839: }
840: } else {
841: p->op = q->op;
842: while(*p->code++ != ',');
843: }
844: break;
845: default:
846: return(q);
847: }
848: p->pop = 0;
849: p->subop = q->subop;
850: } else
851: return(q);
852: uses[r] = 0;
853: if(q->subop == DOUBLE)
854: uses[r+1] = 0;
855: { /* undo any effect on uses in the area between p and q,
856: * as we are going over it again */
857: register struct node *b;
858: for(b=p; b!=q; b=b->back) {
859: for(r=0; r<NUSE; r++) {
860: if(uses[r] == b)
861: uses[r] = 0;
862: if(useacc == b)
863: useacc = 0;
864: }
865: }
866: }
867: return(p->forw); /* make p the next for bflow */
868: }
869: /* it's a store to reg which isnt used elsewhere */
870: if((p=q->forw)->op == CBR) {
871: q->op = TSTF;
872: q->pop = 0;
873: q->code = 0;
874: } else {
875: delnode(q); nst++;
876: if(p->op ==STF || p->op==TSTF || p->op==PUSHD) {
877: if(useacc == p)
878: useacc = 0;
879: return(p->forw); /* so ldmov can be used on p */
880: }
881: }
882: return(p);
883: }
884:
885: /* try to change load/store sequences to movl */
886: ldmov(q)
887: register struct node *q;
888: {
889: register struct node *p;
890: register char *s, *pcod, *cp;
891: char *dlsw();
892:
893: p = q->back;
894: if(!(useacc==0 && (q->op==STF || q->op==TSTF || q->op==PUSHD)
895: && ((p->op==LDF && p->subop==q->subop) || (p->op==LDFD && q->subop==DOUBLE))))
896: return(0);
897: pcod = p->code;
898: cp = p->code;
899: /* prepare args for movl/pushl */
900: if(q->op!=TSTF && q->subop==DOUBLE) {
901: if(p->op == LDF) {
902: if((s = dlsw(p->code)) == NULL)
903: return(0);
904: strcpy(line, s);
905: if(q->op == STF) {
906: strcat(line, ",");
907: if((s = dlsw(q->code)) == NULL)
908: return(0);
909: strcat(line, s);
910: p->op = MOV;
911: } else
912: p->op = PUSH;
913: } else { /* LDFD */
914: if(q->op == STF) {
915: if((s = dlsw(q->code)) == NULL)
916: return(0);
917: } else
918: s = "-(sp)";
919: strcpy(line, s);
920: p->op = CLR;
921: }
922: p->pop = 0;
923: p->subop = LONG;
924: p->code = copy(line);
925: } else
926: {
927: if ((p->op == LDF) && (p->subop == DOUBLE) &&
928: (indexa(cp))) return(0);
929: delnode(p);
930: }
931: strcpy(line, pcod);
932: if(q->op == STF) { /* ldf x; stf y ==> movl x,y */
933: strcat(line, ",");
934: strcat(line, q->code);
935: q->op = MOV;
936: nst++;
937: } else if(q->op == TSTF) /* ldf x; tstf ==> tstl x */
938: q->op = TST;
939: else /* ldd x; pushd ==> pushl x+4; pushl x */
940: q->op = PUSH;
941: q->pop = 0;
942: q->subop = LONG;
943: q->code = copy(line);
944: nld++;
945: return(1);
946: }
947:
948: /* reconstruct the address of l.s.w. of a double operand */
949: char *
950: dlsw(d)
951: register char *d;
952: {
953: register char *s, *t;
954: register int r;
955: static char lsw[C2_ASIZE];
956:
957: if(d[0] == '*' || d[0] == '$')
958: return(NULL);
959: t = lsw;
960: if((r=isreg(d)) >= 0)
961: sprintf(t, "r%d", r+1);
962: else {
963: for(s=d; *s && *s!='('; *t++ = *s++)
964: if(*s == '[')
965: return(NULL);
966: *t++ = '+'; *t++ = '4';
967: while(*t++ = *s)
968: if(*s++ == '[')
969: return(NULL);
970: }
971: return(lsw);
972: }
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