1 /*-------------------------------------------------------------------------
3 SDCCBBlock.c - routines to manipulate basic Blocks
5 Written By - Sandeep Dutta . sandeep.dutta@usa.net (1998)
7 This program is free software; you can redistribute it and/or modify it
8 under the terms of the GNU General Public License as published by the
9 Free Software Foundation; either version 2, or (at your option) any
12 This program is distributed in the hope that it will be useful,
13 but WITHOUT ANY WARRANTY; without even the implied warranty of
14 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
15 GNU General Public License for more details.
17 You should have received a copy of the GNU General Public License
18 along with this program; if not, write to the Free Software
19 Foundation, 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
21 In other words, you are welcome to use, share and improve this program.
22 You are forbidden to forbid anyone else to use, share and improve
23 what you give them. Help stamp out software-hoarding!
24 -------------------------------------------------------------------------*/
30 set *graphEdges = NULL ; /* list of edges in this flow graph */
32 /*-----------------------------------------------------------------*/
33 /* printEntryLabel - prints entry label of a ebblock */
34 /*-----------------------------------------------------------------*/
35 DEFSETFUNC(printEntryLabel)
39 fprintf (stdout," %-20s ",bp->entryLabel->name);
43 /*-----------------------------------------------------------------*/
44 /* neweBBlock - allocate & return a new extended basic block */
45 /*-----------------------------------------------------------------*/
46 eBBlock *neweBBlock ()
50 ebb = Safe_calloc(1,sizeof(eBBlock));
54 /*-----------------------------------------------------------------*/
55 /* newEdge - allocates & initialises an edge to given values */
56 /*-----------------------------------------------------------------*/
57 edge *newEdge (eBBlock *from, eBBlock *to)
61 ep = Safe_calloc(1,sizeof(edge));
68 /*-----------------------------------------------------------------*/
69 /* dumpLiveRanges - dump liverange information into a file */
70 /*-----------------------------------------------------------------*/
71 void dumpLiveRanges (char *ext,hTab *liveRanges)
78 /* create the file name */
79 strcpy(buffer,srcFileName);
82 if (!(file = fopen(buffer,"a+"))) {
83 werror(E_FILE_OPEN_ERR,buffer);
89 for (sym = hTabFirstItem(liveRanges,&k); sym ;
90 sym = hTabNextItem(liveRanges,&k)) {
92 fprintf (file,"%s [k%d lr%d:%d so:%d]{ re%d rm%d}",
93 (sym->rname[0] ? sym->rname : sym->name),
95 sym->liveFrom,sym->liveTo,
97 sym->isreqv,sym->remat
100 fprintf(file,"{"); printTypeChain(sym->type,file);
101 if (sym->usl.spillLoc) {
102 fprintf(file,"}{ sir@ %s",sym->usl.spillLoc->rname);
106 /* if assigned to registers */
110 if (sym->usl.spillLoc)
111 fprintf(file,"[%s]",(sym->usl.spillLoc->rname[0] ?
112 sym->usl.spillLoc->rname :
113 sym->usl.spillLoc->name));
115 fprintf(file,"[err]");
117 fprintf(file,"[remat]");
122 for(i=0;i<sym->nRegs;i++)
123 fprintf(file,"%s ", port->getRegName(sym->regs[i]));
132 /*-----------------------------------------------------------------*/
133 /* dumpEbbsToFileExt - writeall the basic blocks to a file */
134 /*-----------------------------------------------------------------*/
135 void dumpEbbsToFileExt (char *ext,eBBlock **ebbs, int count)
141 /* create the file name */
142 strcpy(buffer,srcFileName);
145 if (!(of = fopen(buffer,"a+"))) {
146 werror(E_FILE_OPEN_ERR,buffer);
152 for (i=0; i < count ; i++ ) {
153 fprintf(of,"\n----------------------------------------------------------------\n");
154 fprintf(of,"Basic Block %s : loop Depth = %d noPath = %d , lastinLoop = %d\n",
155 ebbs[i]->entryLabel->name,
158 ebbs[i]->isLastInLoop);
159 fprintf(of,"\ndefines bitVector :");
160 bitVectDebugOn(ebbs[i]->defSet,of);
161 fprintf(of,"\nlocal defines bitVector :");
162 bitVectDebugOn(ebbs[i]->ldefs,of);
163 fprintf(of,"\npointers Set bitvector :");
164 bitVectDebugOn(ebbs[i]->ptrsSet,of);
165 fprintf(of,"\n----------------------------------------------------------------\n");
166 printiCChain(ebbs[i]->sch,of);
171 /*-----------------------------------------------------------------*/
172 /* iCode2eBBlock - converts a sequnce till label to a ebb */
173 /*-----------------------------------------------------------------*/
174 eBBlock *iCode2eBBlock (iCode *ic)
177 eBBlock *ebb = neweBBlock(); /* a llocate an entry */
179 /* put the first one unconditionally */
182 /* if this is a label then */
184 ebb->entryLabel = ic->argLabel.label ;
186 sprintf(buffer,"_eBBlock%d",eBBNum++);
187 ebb->entryLabel = newSymbol(buffer,1);
188 ebb->entryLabel->key = labelKey++;
193 ic->op == JUMPTABLE ||
199 if ((ic->next && ic->next->op == LABEL) ||
201 ebb->ech = ebb->sch ;
205 /* loop thru till we find one with a label */
206 for ( loop = ic->next ; loop ; loop = loop->next ) {
208 /* if this is the last one */
211 /* if this is a function call */
212 if (loop->op == CALL || loop->op == PCALL) {
215 currFunc->hasFcall = 1;
218 /* if the next one is a label */
219 /* if this is a goto or ifx */
220 if (loop->next->op == LABEL ||
222 loop->op == JUMPTABLE ||
227 /* mark the end of the chain */
233 /*-----------------------------------------------------------------*/
234 /* eBBWithEntryLabel - finds the basic block with the entry label */
235 /*-----------------------------------------------------------------*/
236 eBBlock *eBBWithEntryLabel ( eBBlock **ebbs , symbol *eLabel, int count)
240 for ( i = 0 ; i < count ; i++ ) {
241 if (isSymbolEqual(ebbs[i]->entryLabel,eLabel))
249 /*-----------------------------------------------------------------*/
250 /* ifFromIs - will return 1 if the from block matches this */
251 /*-----------------------------------------------------------------*/
255 V_ARG(eBBlock *,this);
257 if (ep->from == this)
264 /*-----------------------------------------------------------------*/
265 /* edgesTo - returns a set of edges with to == supplied value */
266 /*-----------------------------------------------------------------*/
267 set *edgesTo ( eBBlock *to )
272 for (loop = setFirstItem(graphEdges) ; loop ; loop = setNextItem(graphEdges))
273 if (loop->to == to && !loop->from->noPath)
274 addSet(&result,loop->from);
280 /*-----------------------------------------------------------------*/
281 /* addiCodeToeBBlock - will add an iCode to the end of a block */
282 /*-----------------------------------------------------------------*/
283 void addiCodeToeBBlock ( eBBlock *ebp, iCode *ic , iCode *ip)
285 ic->prev = ic->next = NULL;
286 /* if the insert point is given */
288 ic->lineno = ip->lineno;
299 /* if the block has no instructions */
300 if (ebp->ech == NULL ) {
301 ebp->sch = ebp->ech = ic;
306 /* if the last instruction is a goto */
307 /* we add it just before the goto */
308 if ( ebp->ech->op == GOTO || ebp->ech->op == JUMPTABLE
309 || ebp->ech->op == RETURN)
311 ic->lineno = ebp->ech->lineno;
312 ic->prev = ebp->ech->prev;
315 if (!ic->prev) /* was the last only on in the block */
322 /* if the last one was a ifx statement we check to see */
323 /* if the condition was defined in the previous instruction */
324 /* if this is true then we put it before the condition else */
325 /* we put it before if, this is to reduce register pressure,*/
326 /* we don't have to hold condition too long in a register */
327 if ( ebp->ech->op == IFX ) {
330 /* if ( !ebp->ech->prev ) */
331 /* ipoint = ebp->ech ; */
333 /* if (!IC_RESULT(ebp->ech->prev)) */
334 /* ipoint = ebp->ech ; */
336 /* if (IC_COND(ebp->ech)->key == IC_RESULT(ebp->ech->prev)->key) */
337 /* ipoint = ebp->ech->prev; */
339 /* ipoint = ebp->ech ; */
341 ic->lineno = ipoint->lineno;
342 ic->prev = ipoint->prev;
352 /* will add it to the very end */
362 /*-----------------------------------------------------------------*/
363 /* remiCodeFromeBBlock - remove an iCode from BBlock */
364 /*-----------------------------------------------------------------*/
365 void remiCodeFromeBBlock (eBBlock *ebb, iCode *ic)
368 ic->prev->next = ic->next ;
370 ebb->sch = ic->next ;
373 ic->next->prev = ic->prev;
378 /*-----------------------------------------------------------------*/
379 /* iCodeBreakDown : breakDown iCode chain to blocks */
380 /*-----------------------------------------------------------------*/
381 eBBlock **iCodeBreakDown (iCode *ic, int *count)
383 eBBlock **ebbs = NULL ;
388 /* allocate for the first entry */
390 ebbs = Safe_calloc(1,sizeof(eBBlock **));
394 /* convert 2 block */
395 eBBlock *ebb = iCode2eBBlock(loop);
396 loop = ebb->ech->next ;
398 ebb->ech->next = NULL ; /* mark the end of this chain */
401 ebb->bbnum = *count ; /* save this block number */
402 /* put it in the array */
403 ebbs[(*count)++] = ebb ;
405 /* allocate for the next one. Remember to clear the new */
406 /* pointer at the end, that was created by realloc. */
408 ebbs = Safe_realloc(ebbs,(*count + 1)*sizeof(eBBlock **)) ;
412 /* if this one ends in a goto or a conditional */
413 /* branch then check if the block it is going */
414 /* to already exists, if yes then this could */
415 /* be a loop, add a preheader to the block it */
416 /* goes to if it does not already have one */
417 if (ebbs[(*count) - 1]->ech &&
418 (ebbs[(*count) - 1]->ech->op == GOTO ||
419 ebbs[(*count) - 1]->ech->op == IFX )) {
424 if (ebbs[(*count) - 1]->ech->op == GOTO)
425 label = IC_LABEL(ebbs[(*count)-1]->ech);
427 if (!(label = IC_TRUE(ebbs[(*count)-1]->ech)))
428 label = IC_FALSE(ebbs[(*count)-1]->ech);
430 if ((destBlock = eBBWithEntryLabel(ebbs,label,(*count))) &&
431 destBlock->preHeader == NULL &&
432 otherPathsPresent(ebbs,destBlock) ) {
434 symbol *preHeaderLabel = newiTempPreheaderLabel();
438 /* go thru all block replacing the entryLabel with new label */
439 /* till we reach the block , then we insert a new ebblock */
440 for ( i = 0 ; i < (*count) ; i++ ) {
441 if ( ebbs[i] == destBlock )
443 replaceLabel(ebbs[i],label,preHeaderLabel);
448 /* if we have stopped at the block , allocate for an extra one */
450 ebbs = Safe_realloc(ebbs,(*count + 1)*sizeof(eBBlock **)) ;
454 /* then move the block down one count */
455 pBlock = ebbs[j = i];
456 for ( i += 1; i < (*count) ; i++ ) {
465 destBlock->preHeader = ebbs[j] = neweBBlock();
467 ebbs[j]->entryLabel = preHeaderLabel ;
468 ebbs[j]->sch = ebbs[j]->ech = newiCodeLabelGoto(LABEL,preHeaderLabel);
469 ebbs[j]->sch->lineno = destBlock->sch->lineno;
475 ebbs[*count] = NULL ;
480 /*-----------------------------------------------------------------*/
481 /* replaceSymBySym : - replace operand by operand in blocks */
482 /* replaces only left & right in blocks */
483 /*-----------------------------------------------------------------*/
484 void replaceSymBySym (set *sset, operand *src, operand *dest)
489 /* for all blocks in the set do */
490 for ( loop = sset ; loop ; loop = loop->next) {
493 rBlock = loop->item ;
494 /* for all instructions in this block do */
495 for ( ic = rBlock->sch ; ic ; ic = ic->next ) {
497 /* if we find usage */
498 if (ic->op == IFX && isOperandEqual(src,IC_COND(ic))) {
499 bitVectUnSetBit (OP_USES(IC_COND(ic)),ic->key);
500 IC_COND(ic) = operandFromOperand(dest);
501 OP_USES(dest) = bitVectSetBit (OP_USES(dest),ic->key);
505 if (isOperandEqual(IC_RIGHT(ic),src)) {
506 bitVectUnSetBit (OP_USES(IC_RIGHT(ic)),ic->key);
507 IC_RIGHT(ic) = operandFromOperand(dest);
508 IC_RIGHT(ic)->isaddr = 0;
509 OP_USES(dest) = bitVectSetBit (OP_USES(dest),ic->key);
512 if (isOperandEqual(IC_LEFT(ic),src)) {
513 bitVectUnSetBit (OP_USES(IC_LEFT(ic)),ic->key);
514 if (POINTER_GET(ic) && IS_ITEMP(dest)) {
515 IC_LEFT(ic) = operandFromOperand(dest);
516 IC_LEFT(ic)->isaddr = 1;
518 IC_LEFT(ic) = operandFromOperand(dest);
519 IC_LEFT(ic)->isaddr = 0;
521 OP_USES(dest) = bitVectSetBit (OP_USES(dest),ic->key);
524 /* special case for pointer sets */
525 if (POINTER_SET(ic) &&
526 isOperandEqual(IC_RESULT(ic),src)) {
527 bitVectUnSetBit (OP_USES(IC_RESULT(ic)),ic->key);
528 IC_RESULT(ic) = operandFromOperand(dest);
529 IC_RESULT(ic)->isaddr = 1;
530 OP_USES(dest) = bitVectSetBit(OP_USES(dest),ic->key);
536 /*-----------------------------------------------------------------*/
537 /* replaceLabel - replace reference to one label by another */
538 /*-----------------------------------------------------------------*/
539 void replaceLabel(eBBlock *ebp, symbol *fromLbl, symbol *toLbl)
546 for (ic = ebp->sch ; ic ; ic = ic->next ) {
550 if (isSymbolEqual(IC_LABEL(ic),fromLbl))
551 IC_LABEL(ic) = toLbl;
555 if (IC_TRUE(ic) && isSymbolEqual(IC_TRUE(ic),fromLbl))
556 IC_TRUE(ic) = toLbl ;
558 if (isSymbolEqual(IC_FALSE(ic),fromLbl))
559 IC_FALSE(ic) = toLbl;
569 /*-----------------------------------------------------------------*/
570 /* iCodeFromeBBlock - convert basic block to iCode chain */
571 /*-----------------------------------------------------------------*/
572 iCode *iCodeFromeBBlock ( eBBlock **ebbs, int count)
575 iCode *ric = ebbs[0]->sch ;
576 iCode *lic = ebbs[0]->ech ;
578 for ( ; i < count; i++ ) {
579 if ( ebbs[i]->sch == NULL)
582 if ( ebbs[i]->noPath &&
583 (ebbs[i]->entryLabel != entryLabel &&
584 ebbs[i]->entryLabel != returnLabel )) {
585 werror(W_CODE_UNREACH,ebbs[i]->sch->filename,ebbs[i]->sch->lineno);
589 lic->next = ebbs[i]->sch ;
590 lic->next->prev = lic;
597 /*-----------------------------------------------------------------*/
598 /* otherPathsPresent - determines if there is a path from _entry */
599 /* to this block in a half constructed set of blocks */
600 /*-----------------------------------------------------------------*/
601 int otherPathsPresent (eBBlock **ebbs, eBBlock *this)
605 /* for all blocks preceding this block */
606 for ( i = 0 ; i < this->bbnum ; i++ ) {
609 /* if there is a reference to the entry label of this block */
610 for ( ic = ebbs[i]->sch ; ic ; ic = ic->next ) {
613 if (IC_LABEL(ic)->key == this->entryLabel->key)
619 if (IC_TRUE(ic)->key == this->entryLabel->key)
622 if (IC_FALSE(ic)->key == this->entryLabel->key)
629 /* comes here means we have not found it yet */
630 /* in this case check if the previous block */
631 /* ends in a goto if it does then we have no */
632 /* path else we have a path */
633 if (this->bbnum && ebbs[this->bbnum - 1]->ech &&
634 ebbs[this->bbnum - 1]->ech->op == GOTO )