1 /*------------------------------------------------------------------------
3 SDCCralloc.c - source file for register allocation. (8051) specific
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 /*-----------------------------------------------------------------*/
31 /* At this point we start getting processor specific although */
32 /* some routines are non-processor specific & can be reused when */
33 /* targetting other processors. The decision for this will have */
34 /* to be made on a routine by routine basis */
35 /* routines used to pack registers are most definitely not reusable*/
36 /* since the pack the registers depending strictly on the MCU */
37 /*-----------------------------------------------------------------*/
46 bitVect *funcrUsed; /* registers used in a function */
51 /* Shared with gen.c */
52 int ds390_ptrRegReq; /* one byte pointer register required */
58 { REG_GPR ,R2_IDX , REG_GPR , "r2", "ar2", "0", 2, 1 },
59 { REG_GPR ,R3_IDX , REG_GPR , "r3", "ar3", "0", 3, 1 },
60 { REG_GPR ,R4_IDX , REG_GPR , "r4", "ar4", "0", 4, 1 },
61 { REG_GPR ,R5_IDX , REG_GPR , "r5", "ar5", "0", 5, 1 },
62 { REG_GPR ,R6_IDX , REG_GPR , "r6", "ar6", "0", 6, 1 },
63 { REG_GPR ,R7_IDX , REG_GPR , "r7", "ar7", "0", 7, 1 },
64 { REG_PTR ,R0_IDX , REG_PTR , "r0" , "ar0", "0", 0, 1 },
65 { REG_PTR ,R1_IDX , REG_PTR , "r1" , "ar1", "0", 1, 1 },
66 { REG_GPR ,X8_IDX , REG_GPR , "x8", "x8" , "xreg", 0, 1 },
67 { REG_GPR ,X9_IDX , REG_GPR , "x9", "x9" , "xreg", 1, 1 },
68 { REG_GPR ,X10_IDX,REG_GPR , "x10", "x10", "xreg", 2, 1 },
69 { REG_GPR ,X11_IDX,REG_GPR , "x11", "x11", "xreg", 3, 1 },
70 { REG_GPR ,X12_IDX,REG_GPR , "x12", "x12", "xreg", 4, 1 },
71 { REG_CND ,CND_IDX,REG_CND , "C" , "C" , "xreg", 0, 1 },
74 static void spillThis (symbol *);
76 /*-----------------------------------------------------------------*/
77 /* allocReg - allocates register of given type */
78 /*-----------------------------------------------------------------*/
79 static regs *allocReg (short type)
83 for ( i = 0 ; i < ds390_nRegs ; i++ ) {
85 /* if type is given as 0 then any
86 free register will do */
89 regs390[i].isFree = 0;
92 bitVectSetBit(currFunc->regsUsed,i);
95 /* other wise look for specific type
97 if (regs390[i].isFree &&
98 regs390[i].type == type) {
99 regs390[i].isFree = 0;
102 bitVectSetBit(currFunc->regsUsed,i);
109 /*-----------------------------------------------------------------*/
110 /* ds390_regWithIdx - returns pointer to register wit index number */
111 /*-----------------------------------------------------------------*/
112 regs *ds390_regWithIdx (int idx)
116 for (i=0;i < ds390_nRegs;i++)
117 if (regs390[i].rIdx == idx)
120 werror(E_INTERNAL_ERROR,__FILE__,__LINE__,
121 "regWithIdx not found");
125 /*-----------------------------------------------------------------*/
126 /* freeReg - frees a register */
127 /*-----------------------------------------------------------------*/
128 static void freeReg (regs *reg)
134 /*-----------------------------------------------------------------*/
135 /* nFreeRegs - returns number of free registers */
136 /*-----------------------------------------------------------------*/
137 static int nFreeRegs (int type)
142 for (i = 0 ; i < ds390_nRegs; i++ )
143 if (regs390[i].isFree && regs390[i].type == type)
148 /*-----------------------------------------------------------------*/
149 /* nfreeRegsType - free registers with type */
150 /*-----------------------------------------------------------------*/
151 static int nfreeRegsType (int type)
154 if (type == REG_PTR) {
155 if ((nfr = nFreeRegs(type)) == 0)
156 return nFreeRegs(REG_GPR);
159 return nFreeRegs(type);
163 /*-----------------------------------------------------------------*/
164 /* allDefsOutOfRange - all definitions are out of a range */
165 /*-----------------------------------------------------------------*/
166 static bool allDefsOutOfRange (bitVect *defs,int fseq, int toseq)
173 for ( i = 0 ;i < defs->size ; i++ ) {
176 if (bitVectBitValue(defs,i) &&
177 (ic = hTabItemWithKey(iCodehTab,i)) &&
178 ( ic->seq >= fseq && ic->seq <= toseq))
187 /*-----------------------------------------------------------------*/
188 /* computeSpillable - given a point find the spillable live ranges */
189 /*-----------------------------------------------------------------*/
190 static bitVect *computeSpillable (iCode *ic)
194 /* spillable live ranges are those that are live at this
195 point . the following categories need to be subtracted
197 a) - those that are already spilt
198 b) - if being used by this one
199 c) - defined by this one */
201 spillable = bitVectCopy(ic->rlive);
203 bitVectCplAnd(spillable,_G.spiltSet); /* those already spilt */
205 bitVectCplAnd(spillable,ic->uses); /* used in this one */
206 bitVectUnSetBit(spillable,ic->defKey);
207 spillable = bitVectIntersect(spillable,_G.regAssigned);
212 /*-----------------------------------------------------------------*/
213 /* noSpilLoc - return true if a variable has no spil location */
214 /*-----------------------------------------------------------------*/
215 static int noSpilLoc (symbol *sym, eBBlock *ebp,iCode *ic)
217 return (sym->usl.spillLoc ? 0 : 1);
220 /*-----------------------------------------------------------------*/
221 /* hasSpilLoc - will return 1 if the symbol has spil location */
222 /*-----------------------------------------------------------------*/
223 static int hasSpilLoc (symbol *sym, eBBlock *ebp, iCode *ic)
225 return (sym->usl.spillLoc ? 1 : 0);
228 /*-----------------------------------------------------------------*/
229 /* directSpilLoc - will return 1 if the splilocation is in direct */
230 /*-----------------------------------------------------------------*/
231 static int directSpilLoc (symbol *sym, eBBlock *ebp, iCode *ic)
233 if ( sym->usl.spillLoc &&
234 (IN_DIRSPACE(SPEC_OCLS(sym->usl.spillLoc->etype))))
240 /*-----------------------------------------------------------------*/
241 /* hasSpilLocnoUptr - will return 1 if the symbol has spil location*/
242 /* but is not used as a pointer */
243 /*-----------------------------------------------------------------*/
244 static int hasSpilLocnoUptr (symbol *sym, eBBlock *ebp, iCode *ic)
246 return ((sym->usl.spillLoc && !sym->uptr) ? 1 : 0);
249 /*-----------------------------------------------------------------*/
250 /* rematable - will return 1 if the remat flag is set */
251 /*-----------------------------------------------------------------*/
252 static int rematable (symbol *sym, eBBlock *ebp, iCode *ic)
257 /*-----------------------------------------------------------------*/
258 /* notUsedInBlock - not used in this block */
259 /*-----------------------------------------------------------------*/
260 static int notUsedInBlock (symbol *sym, eBBlock *ebp, iCode *ic)
262 return (!bitVectBitsInCommon(sym->defs,ebp->usesDefs) &&
263 allDefsOutOfRange (sym->defs,ebp->fSeq,ebp->lSeq));
264 /* return (!bitVectBitsInCommon(sym->defs,ebp->usesDefs)); */
267 /*-----------------------------------------------------------------*/
268 /* notUsedInRemaining - not used or defined in remain of the block */
269 /*-----------------------------------------------------------------*/
270 static int notUsedInRemaining (symbol *sym, eBBlock *ebp, iCode *ic)
272 return ((usedInRemaining (operandFromSymbol(sym),ic) ? 0 : 1) &&
273 allDefsOutOfRange (sym->defs,ebp->fSeq,ebp->lSeq));
276 /*-----------------------------------------------------------------*/
277 /* allLRs - return true for all */
278 /*-----------------------------------------------------------------*/
279 static int allLRs (symbol *sym, eBBlock *ebp, iCode *ic)
284 /*-----------------------------------------------------------------*/
285 /* liveRangesWith - applies function to a given set of live range */
286 /*-----------------------------------------------------------------*/
287 static set *liveRangesWith (bitVect *lrs, int (func)(symbol *,eBBlock *, iCode *),
288 eBBlock *ebp, iCode *ic)
293 if (!lrs || !lrs->size)
296 for ( i = 1 ; i < lrs->size ; i++ ) {
298 if (!bitVectBitValue(lrs,i))
301 /* if we don't find it in the live range
302 hash table we are in serious trouble */
303 if (!(sym = hTabItemWithKey(liveRanges,i))) {
304 werror(E_INTERNAL_ERROR,__FILE__,__LINE__,
305 "liveRangesWith could not find liveRange");
309 if (func(sym,ebp,ic) && bitVectBitValue(_G.regAssigned,sym->key))
310 addSetHead(&rset,sym);
317 /*-----------------------------------------------------------------*/
318 /* leastUsedLR - given a set determines which is the least used */
319 /*-----------------------------------------------------------------*/
320 static symbol *leastUsedLR (set *sset)
322 symbol *sym = NULL, *lsym = NULL ;
324 sym = lsym = setFirstItem(sset);
329 for (; lsym; lsym = setNextItem(sset)) {
331 /* if usage is the same then prefer
332 the spill the smaller of the two */
333 if ( lsym->used == sym->used )
334 if (getSize(lsym->type) < getSize(sym->type))
338 if (lsym->used < sym->used )
343 setToNull((void **)&sset);
348 /*-----------------------------------------------------------------*/
349 /* noOverLap - will iterate through the list looking for over lap */
350 /*-----------------------------------------------------------------*/
351 static int noOverLap (set *itmpStack, symbol *fsym)
356 for (sym = setFirstItem(itmpStack); sym;
357 sym = setNextItem(itmpStack)) {
358 if (sym->liveTo > fsym->liveFrom )
366 /*-----------------------------------------------------------------*/
367 /* isFree - will return 1 if the a free spil location is found */
368 /*-----------------------------------------------------------------*/
369 static DEFSETFUNC(isFree)
372 V_ARG(symbol **,sloc);
373 V_ARG(symbol *,fsym);
375 /* if already found */
379 /* if it is free && and the itmp assigned to
380 this does not have any overlapping live ranges
381 with the one currently being assigned and
382 the size can be accomodated */
384 noOverLap(sym->usl.itmpStack,fsym) &&
385 getSize(sym->type) >= getSize(fsym->type)) {
393 /*-----------------------------------------------------------------*/
394 /* spillLRWithPtrReg :- will spil those live ranges which use PTR */
395 /*-----------------------------------------------------------------*/
396 static void spillLRWithPtrReg (symbol *forSym)
402 if (!_G.regAssigned ||
403 bitVectIsZero(_G.regAssigned))
406 r0 = ds390_regWithIdx(R0_IDX);
407 r1 = ds390_regWithIdx(R1_IDX);
409 /* for all live ranges */
410 for (lrsym = hTabFirstItem(liveRanges,&k) ; lrsym ;
411 lrsym = hTabNextItem(liveRanges,&k) ) {
414 /* if no registers assigned to it or
416 /* if it does not overlap with this then
417 not need to spill it */
419 if (lrsym->isspilt || !lrsym->nRegs ||
420 (lrsym->liveTo < forSym->liveFrom))
423 /* go thru the registers : if it is either
424 r0 or r1 then spil it */
425 for (j = 0 ; j < lrsym->nRegs ; j++ )
426 if (lrsym->regs[j] == r0 ||
427 lrsym->regs[j] == r1 ) {
435 /*-----------------------------------------------------------------*/
436 /* createStackSpil - create a location on the stack to spil */
437 /*-----------------------------------------------------------------*/
438 static symbol *createStackSpil (symbol *sym)
441 int useXstack, model, noOverlay;
445 /* first go try and find a free one that is already
446 existing on the stack */
447 if (applyToSet(_G.stackSpil,isFree,&sloc, sym)) {
448 /* found a free one : just update & return */
449 sym->usl.spillLoc = sloc;
452 addSetHead(&sloc->usl.itmpStack,sym);
456 /* could not then have to create one , this is the hard part
457 we need to allocate this on the stack : this is really a
458 hack!! but cannot think of anything better at this time */
460 if (sprintf(slocBuffer,"sloc%d",_G.slocNum++) >= sizeof(slocBuffer))
462 fprintf(stderr, "***Internal error: slocBuffer overflowed: %s:%d\n",
467 sloc = newiTemp(slocBuffer);
469 /* set the type to the spilling symbol */
470 sloc->type = copyLinkChain(sym->type);
471 sloc->etype = getSpec(sloc->type);
472 SPEC_SCLS(sloc->etype) = options.model ? S_XDATA : S_DATA;
473 SPEC_EXTR(sloc->etype) = 0;
475 /* we don't allow it to be allocated`
476 onto the external stack since : so we
477 temporarily turn it off ; we also
478 turn off memory model to prevent
479 the spil from going to the external storage
480 and turn off overlaying
483 useXstack = options.useXstack;
484 model = options.model;
485 noOverlay = options.noOverlay;
486 options.noOverlay = 1;
488 /* options.model = options.useXstack = 0; */
492 options.useXstack = useXstack;
493 options.model = model;
494 options.noOverlay = noOverlay;
495 sloc->isref = 1; /* to prevent compiler warning */
497 /* if it is on the stack then update the stack */
498 if (IN_STACK(sloc->etype)) {
499 currFunc->stack += getSize(sloc->type);
500 _G.stackExtend += getSize(sloc->type);
502 _G.dataExtend += getSize(sloc->type);
504 /* add it to the _G.stackSpil set */
505 addSetHead(&_G.stackSpil,sloc);
506 sym->usl.spillLoc = sloc;
509 /* add it to the set of itempStack set
510 of the spill location */
511 addSetHead(&sloc->usl.itmpStack,sym);
515 /*-----------------------------------------------------------------*/
516 /* isSpiltOnStack - returns true if the spil location is on stack */
517 /*-----------------------------------------------------------------*/
518 static bool isSpiltOnStack (symbol *sym)
528 /* if (sym->_G.stackSpil) */
531 if (!sym->usl.spillLoc)
534 etype = getSpec(sym->usl.spillLoc->type);
541 /*-----------------------------------------------------------------*/
542 /* spillThis - spils a specific operand */
543 /*-----------------------------------------------------------------*/
544 static void spillThis (symbol *sym)
547 /* if this is rematerializable or has a spillLocation
548 we are okay, else we need to create a spillLocation
550 if (!(sym->remat || sym->usl.spillLoc))
551 createStackSpil (sym);
554 /* mark it has spilt & put it in the spilt set */
556 _G.spiltSet = bitVectSetBit(_G.spiltSet,sym->key);
558 bitVectUnSetBit(_G.regAssigned,sym->key);
560 for (i = 0 ; i < sym->nRegs ; i++)
563 freeReg(sym->regs[i]);
567 /* if spilt on stack then free up r0 & r1
568 if they could have been assigned to some
570 if (!ds390_ptrRegReq && isSpiltOnStack(sym)) {
572 spillLRWithPtrReg(sym);
575 if (sym->usl.spillLoc && !sym->remat)
576 sym->usl.spillLoc->allocreq = 1;
580 /*-----------------------------------------------------------------*/
581 /* selectSpil - select a iTemp to spil : rather a simple procedure */
582 /*-----------------------------------------------------------------*/
583 static symbol *selectSpil (iCode *ic, eBBlock *ebp, symbol *forSym)
585 bitVect *lrcs= NULL ;
589 /* get the spillable live ranges */
590 lrcs = computeSpillable (ic);
592 /* get all live ranges that are rematerizable */
593 if ((selectS = liveRangesWith(lrcs,rematable,ebp,ic))) {
595 /* return the least used of these */
596 return leastUsedLR(selectS);
599 /* get live ranges with spillLocations in direct space */
600 if ((selectS = liveRangesWith(lrcs,directSpilLoc,ebp,ic))) {
601 sym = leastUsedLR(selectS);
602 strcpy(sym->rname,(sym->usl.spillLoc->rname[0] ?
603 sym->usl.spillLoc->rname :
604 sym->usl.spillLoc->name));
606 /* mark it as allocation required */
607 sym->usl.spillLoc->allocreq = 1;
611 /* if the symbol is local to the block then */
612 if (forSym->liveTo < ebp->lSeq) {
614 /* check if there are any live ranges allocated
615 to registers that are not used in this block */
616 if (!_G.blockSpil && (selectS = liveRangesWith(lrcs,notUsedInBlock,ebp,ic))) {
617 sym = leastUsedLR(selectS);
618 /* if this is not rematerializable */
626 /* check if there are any live ranges that not
627 used in the remainder of the block */
628 if (!_G.blockSpil && (selectS = liveRangesWith(lrcs,notUsedInRemaining,ebp,ic))) {
629 sym = leastUsedLR (selectS);
640 /* find live ranges with spillocation && not used as pointers */
641 if ((selectS = liveRangesWith(lrcs,hasSpilLocnoUptr,ebp,ic))) {
643 sym = leastUsedLR(selectS);
644 /* mark this as allocation required */
645 sym->usl.spillLoc->allocreq = 1;
649 /* find live ranges with spillocation */
650 if ((selectS = liveRangesWith(lrcs,hasSpilLoc,ebp,ic))) {
652 sym = leastUsedLR(selectS);
653 sym->usl.spillLoc->allocreq = 1;
657 /* couldn't find then we need to create a spil
658 location on the stack , for which one? the least
660 if ((selectS = liveRangesWith(lrcs,noSpilLoc,ebp,ic))) {
662 /* return a created spil location */
663 sym = createStackSpil(leastUsedLR(selectS));
664 sym->usl.spillLoc->allocreq = 1;
668 /* this is an extreme situation we will spill
669 this one : happens very rarely but it does happen */
670 spillThis ( forSym );
675 /*-----------------------------------------------------------------*/
676 /* spilSomething - spil some variable & mark registers as free */
677 /*-----------------------------------------------------------------*/
678 static bool spilSomething (iCode *ic, eBBlock *ebp, symbol *forSym)
683 /* get something we can spil */
684 ssym = selectSpil(ic,ebp,forSym);
686 /* mark it as spilt */
688 _G.spiltSet = bitVectSetBit(_G.spiltSet,ssym->key);
690 /* mark it as not register assigned &
691 take it away from the set */
692 bitVectUnSetBit(_G.regAssigned,ssym->key);
694 /* mark the registers as free */
695 for (i = 0 ; i < ssym->nRegs ;i++ )
697 freeReg(ssym->regs[i]);
699 /* if spilt on stack then free up r0 & r1
700 if they could have been assigned to as gprs */
701 if (!ds390_ptrRegReq && isSpiltOnStack(ssym) ) {
703 spillLRWithPtrReg(ssym);
706 /* if this was a block level spil then insert push & pop
707 at the start & end of block respectively */
708 if (ssym->blockSpil) {
709 iCode *nic = newiCode(IPUSH,operandFromSymbol(ssym),NULL);
710 /* add push to the start of the block */
711 addiCodeToeBBlock(ebp,nic,( ebp->sch->op == LABEL ?
712 ebp->sch->next : ebp->sch));
713 nic = newiCode(IPOP,operandFromSymbol(ssym),NULL);
714 /* add pop to the end of the block */
715 addiCodeToeBBlock(ebp,nic,NULL);
718 /* if spilt because not used in the remainder of the
719 block then add a push before this instruction and
720 a pop at the end of the block */
721 if (ssym->remainSpil) {
723 iCode *nic = newiCode(IPUSH,operandFromSymbol(ssym),NULL);
724 /* add push just before this instruction */
725 addiCodeToeBBlock(ebp,nic,ic);
727 nic = newiCode(IPOP,operandFromSymbol(ssym),NULL);
728 /* add pop to the end of the block */
729 addiCodeToeBBlock(ebp,nic,NULL);
738 /*-----------------------------------------------------------------*/
739 /* getRegPtr - will try for PTR if not a GPR type if not spil */
740 /*-----------------------------------------------------------------*/
741 static regs *getRegPtr (iCode *ic, eBBlock *ebp, symbol *sym)
746 /* try for a ptr type */
747 if ((reg = allocReg(REG_PTR)))
750 /* try for gpr type */
751 if ((reg = allocReg(REG_GPR)))
754 /* we have to spil */
755 if (!spilSomething (ic,ebp,sym))
758 /* this looks like an infinite loop but
759 in really selectSpil will abort */
763 /*-----------------------------------------------------------------*/
764 /* getRegGpr - will try for GPR if not spil */
765 /*-----------------------------------------------------------------*/
766 static regs *getRegGpr (iCode *ic, eBBlock *ebp,symbol *sym)
771 /* try for gpr type */
772 if ((reg = allocReg(REG_GPR)))
775 if (!ds390_ptrRegReq)
776 if ((reg = allocReg(REG_PTR)))
779 /* we have to spil */
780 if (!spilSomething (ic,ebp,sym))
783 /* this looks like an infinite loop but
784 in really selectSpil will abort */
788 /*-----------------------------------------------------------------*/
789 /* symHasReg - symbol has a given register */
790 /*-----------------------------------------------------------------*/
791 static bool symHasReg(symbol *sym,regs *reg)
795 for ( i = 0 ; i < sym->nRegs ; i++)
796 if (sym->regs[i] == reg)
802 /*-----------------------------------------------------------------*/
803 /* deassignLRs - check the live to and if they have registers & are*/
804 /* not spilt then free up the registers */
805 /*-----------------------------------------------------------------*/
806 static void deassignLRs (iCode *ic, eBBlock *ebp)
812 for (sym = hTabFirstItem(liveRanges,&k); sym;
813 sym = hTabNextItem(liveRanges,&k)) {
816 /* if it does not end here */
817 if (sym->liveTo > ic->seq )
820 /* if it was spilt on stack then we can
821 mark the stack spil location as free */
823 if (sym->stackSpil) {
824 sym->usl.spillLoc->isFree = 1;
830 if (!bitVectBitValue(_G.regAssigned,sym->key))
833 /* special case check if this is an IFX &
834 the privious one was a pop and the
835 previous one was not spilt then keep track
837 if (ic->op == IFX && ic->prev &&
838 ic->prev->op == IPOP &&
839 !ic->prev->parmPush &&
840 !OP_SYMBOL(IC_LEFT(ic->prev))->isspilt)
841 psym = OP_SYMBOL(IC_LEFT(ic->prev));
846 bitVectUnSetBit(_G.regAssigned,sym->key);
848 /* if the result of this one needs registers
849 and does not have it then assign it right
852 ! (SKIP_IC2(ic) || /* not a special icode */
853 ic->op == JUMPTABLE ||
859 (result = OP_SYMBOL(IC_RESULT(ic))) && /* has a result */
860 result->liveTo > ic->seq && /* and will live beyond this */
861 result->liveTo <= ebp->lSeq && /* does not go beyond this block */
862 result->regType == sym->regType && /* same register types */
863 result->nRegs && /* which needs registers */
864 ! result->isspilt && /* and does not already have them */
866 ! bitVectBitValue(_G.regAssigned,result->key) &&
867 /* the number of free regs + number of regs in this LR
868 can accomodate the what result Needs */
869 ((nfreeRegsType(result->regType) +
870 sym->nRegs) >= result->nRegs)
873 for (i = 0 ; i < result->nRegs ; i++)
875 result->regs[i] = sym->regs[i] ;
877 result->regs[i] = getRegGpr (ic,ebp,result);
879 _G.regAssigned = bitVectSetBit(_G.regAssigned,result->key);
883 /* free the remaining */
884 for (; i < sym->nRegs ; i++) {
886 if (!symHasReg(psym,sym->regs[i]))
887 freeReg(sym->regs[i]);
889 freeReg(sym->regs[i]);
896 /*-----------------------------------------------------------------*/
897 /* reassignLR - reassign this to registers */
898 /*-----------------------------------------------------------------*/
899 static void reassignLR (operand *op)
901 symbol *sym = OP_SYMBOL(op);
904 /* not spilt any more */
905 sym->isspilt = sym->blockSpil = sym->remainSpil = 0;
906 bitVectUnSetBit(_G.spiltSet,sym->key);
908 _G.regAssigned = bitVectSetBit(_G.regAssigned,sym->key);
912 for (i=0;i<sym->nRegs;i++)
913 sym->regs[i]->isFree = 0;
916 /*-----------------------------------------------------------------*/
917 /* willCauseSpill - determines if allocating will cause a spill */
918 /*-----------------------------------------------------------------*/
919 static int willCauseSpill ( int nr, int rt)
921 /* first check if there are any avlb registers
922 of te type required */
924 /* special case for pointer type
925 if pointer type not avlb then
926 check for type gpr */
927 if (nFreeRegs(rt) >= nr)
929 if (nFreeRegs(REG_GPR) >= nr)
932 if (ds390_ptrRegReq) {
933 if (nFreeRegs(rt) >= nr)
936 if (nFreeRegs(REG_PTR) +
937 nFreeRegs(REG_GPR) >= nr)
942 /* it will cause a spil */
946 /*-----------------------------------------------------------------*/
947 /* positionRegs - the allocator can allocate same registers to res-*/
948 /* ult and operand, if this happens make sure they are in the same */
949 /* position as the operand otherwise chaos results */
950 /*-----------------------------------------------------------------*/
951 static void positionRegs (symbol *result, symbol *opsym, int lineno)
953 int count = min(result->nRegs,opsym->nRegs);
954 int i , j = 0, shared = 0;
956 /* if the result has been spilt then cannot share */
961 /* first make sure that they actually share */
962 for ( i = 0 ; i < count; i++ ) {
963 for (j = 0 ; j < count ; j++ ) {
964 if (result->regs[i] == opsym->regs[j] && i !=j) {
972 regs *tmp = result->regs[i];
973 result->regs[i] = result->regs[j];
974 result->regs[j] = tmp;
979 /*-----------------------------------------------------------------*/
980 /* serialRegAssign - serially allocate registers to the variables */
981 /*-----------------------------------------------------------------*/
982 static void serialRegAssign (eBBlock **ebbs, int count)
987 for (i = 0; i < count ; i++ ) {
991 if (ebbs[i]->noPath &&
992 (ebbs[i]->entryLabel != entryLabel &&
993 ebbs[i]->entryLabel != returnLabel ))
996 /* of all instructions do */
997 for (ic = ebbs[i]->sch ; ic ; ic = ic->next) {
999 /* if this is an ipop that means some live
1000 range will have to be assigned again */
1002 reassignLR (IC_LEFT(ic));
1004 /* if result is present && is a true symbol */
1005 if (IC_RESULT(ic) && ic->op != IFX &&
1006 IS_TRUE_SYMOP(IC_RESULT(ic)))
1007 OP_SYMBOL(IC_RESULT(ic))->allocreq = 1;
1009 /* take away registers from live
1010 ranges that end at this instruction */
1011 deassignLRs (ic, ebbs[i]) ;
1013 /* some don't need registers */
1015 ic->op == JUMPTABLE ||
1019 (IC_RESULT(ic) &&POINTER_SET(ic)) )
1022 /* now we need to allocate registers
1023 only for the result */
1024 if (IC_RESULT(ic)) {
1025 symbol *sym = OP_SYMBOL(IC_RESULT(ic));
1031 /* if it does not need or is spilt
1032 or is already assigned to registers
1033 or will not live beyond this instructions */
1036 bitVectBitValue(_G.regAssigned,sym->key) ||
1037 sym->liveTo <= ic->seq)
1040 /* if some liverange has been spilt at the block level
1041 and this one live beyond this block then spil this
1043 if (_G.blockSpil && sym->liveTo > ebbs[i]->lSeq) {
1047 /* if trying to allocate this will cause
1048 a spill and there is nothing to spill
1049 or this one is rematerializable then
1051 willCS = willCauseSpill(sym->nRegs,sym->regType);
1052 spillable = computeSpillable(ic);
1054 (willCS && bitVectIsZero(spillable) ) ) {
1061 /* if it has a spillocation & is used less than
1062 all other live ranges then spill this */
1063 if ( willCS && sym->usl.spillLoc ) {
1066 leastUsedLR(liveRangesWith (spillable ,
1071 leastUsed->used > sym->used) {
1077 /* if we need ptr regs for the right side
1079 if (POINTER_GET(ic) && getSize(OP_SYMBOL(IC_LEFT(ic))->type)
1085 /* else we assign registers to it */
1086 _G.regAssigned = bitVectSetBit(_G.regAssigned,sym->key);
1088 for (j = 0 ; j < sym->nRegs ;j++ ) {
1089 if (sym->regType == REG_PTR)
1090 sym->regs[j] = getRegPtr(ic,ebbs[i],sym);
1092 sym->regs[j] = getRegGpr(ic,ebbs[i],sym);
1094 /* if the allocation falied which means
1095 this was spilt then break */
1099 /* if it shares registers with operands make sure
1100 that they are in the same position */
1101 if (IC_LEFT(ic) && IS_SYMOP(IC_LEFT(ic)) &&
1102 OP_SYMBOL(IC_LEFT(ic))->nRegs && ic->op != '=')
1103 positionRegs(OP_SYMBOL(IC_RESULT(ic)),
1104 OP_SYMBOL(IC_LEFT(ic)),ic->lineno);
1105 /* do the same for the right operand */
1106 if (IC_RIGHT(ic) && IS_SYMOP(IC_RIGHT(ic)) &&
1107 OP_SYMBOL(IC_RIGHT(ic))->nRegs)
1108 positionRegs(OP_SYMBOL(IC_RESULT(ic)),
1109 OP_SYMBOL(IC_RIGHT(ic)),ic->lineno);
1121 /*-----------------------------------------------------------------*/
1122 /* rUmaskForOp :- returns register mask for an operand */
1123 /*-----------------------------------------------------------------*/
1124 static bitVect *rUmaskForOp (operand *op)
1130 /* only temporaries are assigned registers */
1134 sym = OP_SYMBOL(op);
1136 /* if spilt or no registers assigned to it
1138 if (sym->isspilt || !sym->nRegs)
1141 rumask = newBitVect(ds390_nRegs);
1143 for (j = 0; j < sym->nRegs; j++) {
1144 rumask = bitVectSetBit(rumask,
1145 sym->regs[j]->rIdx);
1151 /*-----------------------------------------------------------------*/
1152 /* regsUsedIniCode :- returns bit vector of registers used in iCode*/
1153 /*-----------------------------------------------------------------*/
1154 static bitVect *regsUsedIniCode (iCode *ic)
1156 bitVect *rmask = newBitVect(ds390_nRegs);
1158 /* do the special cases first */
1159 if (ic->op == IFX ) {
1160 rmask = bitVectUnion(rmask,
1161 rUmaskForOp(IC_COND(ic)));
1165 /* for the jumptable */
1166 if (ic->op == JUMPTABLE) {
1167 rmask = bitVectUnion(rmask,
1168 rUmaskForOp(IC_JTCOND(ic)));
1173 /* of all other cases */
1175 rmask = bitVectUnion(rmask,
1176 rUmaskForOp(IC_LEFT(ic)));
1180 rmask = bitVectUnion(rmask,
1181 rUmaskForOp(IC_RIGHT(ic)));
1184 rmask = bitVectUnion(rmask,
1185 rUmaskForOp(IC_RESULT(ic)));
1191 /*-----------------------------------------------------------------*/
1192 /* createRegMask - for each instruction will determine the regsUsed*/
1193 /*-----------------------------------------------------------------*/
1194 static void createRegMask (eBBlock **ebbs, int count)
1198 /* for all blocks */
1199 for (i = 0; i < count ; i++ ) {
1202 if ( ebbs[i]->noPath &&
1203 ( ebbs[i]->entryLabel != entryLabel &&
1204 ebbs[i]->entryLabel != returnLabel ))
1207 /* for all instructions */
1208 for ( ic = ebbs[i]->sch ; ic ; ic = ic->next ) {
1212 if (SKIP_IC2(ic) || !ic->rlive)
1215 /* first mark the registers used in this
1217 ic->rUsed = regsUsedIniCode(ic);
1218 _G.funcrUsed = bitVectUnion(_G.funcrUsed,ic->rUsed);
1220 /* now create the register mask for those
1221 registers that are in use : this is a
1222 super set of ic->rUsed */
1223 ic->rMask = newBitVect(ds390_nRegs+1);
1225 /* for all live Ranges alive at this point */
1226 for (j = 1; j < ic->rlive->size; j++ ) {
1230 /* if not alive then continue */
1231 if (!bitVectBitValue(ic->rlive,j))
1234 /* find the live range we are interested in */
1235 if (!(sym = hTabItemWithKey(liveRanges,j))) {
1236 werror (E_INTERNAL_ERROR,__FILE__,__LINE__,
1237 "createRegMask cannot find live range");
1241 /* if no register assigned to it */
1242 if (!sym->nRegs || sym->isspilt)
1245 /* for all the registers allocated to it */
1246 for (k = 0 ; k < sym->nRegs ;k++)
1249 bitVectSetBit(ic->rMask,sym->regs[k]->rIdx);
1255 /*-----------------------------------------------------------------*/
1256 /* rematStr - returns the rematerialized string for a remat var */
1257 /*-----------------------------------------------------------------*/
1258 static char *rematStr (symbol *sym)
1261 iCode *ic = sym->rematiCode;
1265 /* if plus or minus print the right hand side */
1266 if (ic->op == '+' || ic->op == '-') {
1267 sprintf(s,"0x%04x %c ",(int) operandLitValue(IC_RIGHT(ic)),
1270 ic = OP_SYMBOL(IC_LEFT(ic))->rematiCode;
1274 /* we reached the end */
1275 sprintf(s,"%s",OP_SYMBOL(IC_LEFT(ic))->rname);
1282 /*-----------------------------------------------------------------*/
1283 /* regTypeNum - computes the type & number of registers required */
1284 /*-----------------------------------------------------------------*/
1285 static void regTypeNum ()
1291 /* for each live range do */
1292 for ( sym = hTabFirstItem(liveRanges,&k); sym ;
1293 sym = hTabNextItem(liveRanges,&k)) {
1295 /* if used zero times then no registers needed */
1296 if ((sym->liveTo - sym->liveFrom) == 0)
1300 /* if the live range is a temporary */
1303 /* if the type is marked as a conditional */
1304 if (sym->regType == REG_CND)
1307 /* if used in return only then we don't
1309 if (sym->ruonly || sym->accuse) {
1310 if (IS_AGGREGATE(sym->type) || sym->isptr)
1311 sym->type = aggrToPtr(sym->type,FALSE);
1315 /* if the symbol has only one definition &
1316 that definition is a get_pointer and the
1317 pointer we are getting is rematerializable and
1320 if (bitVectnBitsOn(sym->defs) == 1 &&
1321 (ic = hTabItemWithKey(iCodehTab,
1322 bitVectFirstBit(sym->defs))) &&
1324 !IS_BITVAR(sym->etype)) {
1327 /* if remat in data space */
1328 if (OP_SYMBOL(IC_LEFT(ic))->remat &&
1330 DCL_TYPE(aggrToPtr(sym->type,FALSE)) == POINTER) {
1332 /* create a psuedo symbol & force a spil */
1333 symbol *psym = newSymbol(rematStr(OP_SYMBOL(IC_LEFT(ic))),1);
1334 psym->type = sym->type;
1335 psym->etype = sym->etype;
1336 strcpy(psym->rname,psym->name);
1338 sym->usl.spillLoc = psym;
1342 /* if in data space or idata space then try to
1343 allocate pointer register */
1347 /* if not then we require registers */
1348 sym->nRegs = ((IS_AGGREGATE(sym->type) || sym->isptr ) ?
1349 getSize(sym->type = aggrToPtr(sym->type,FALSE)) :
1350 getSize(sym->type));
1352 if (sym->nRegs > 4) {
1353 fprintf(stderr,"allocated more than 4 or 0 registers for type ");
1354 printTypeChain(sym->type,stderr);fprintf(stderr,"\n");
1357 /* determine the type of register required */
1358 if (sym->nRegs == 1 &&
1359 IS_PTR(sym->type) &&
1361 sym->regType = REG_PTR ;
1363 sym->regType = REG_GPR ;
1366 /* for the first run we don't provide */
1367 /* registers for true symbols we will */
1368 /* see how things go */
1374 /*-----------------------------------------------------------------*/
1375 /* freeAllRegs - mark all registers as free */
1376 /*-----------------------------------------------------------------*/
1377 static void freeAllRegs()
1381 for (i=0;i< ds390_nRegs;i++ )
1382 regs390[i].isFree = 1;
1385 /*-----------------------------------------------------------------*/
1386 /* deallocStackSpil - this will set the stack pointer back */
1387 /*-----------------------------------------------------------------*/
1388 static DEFSETFUNC(deallocStackSpil)
1396 /*-----------------------------------------------------------------*/
1397 /* farSpacePackable - returns the packable icode for far variables */
1398 /*-----------------------------------------------------------------*/
1399 static iCode *farSpacePackable (iCode *ic)
1403 /* go thru till we find a definition for the
1404 symbol on the right */
1405 for ( dic = ic->prev ; dic ; dic = dic->prev) {
1407 /* if the definition is a call then no */
1408 if ((dic->op == CALL || dic->op == PCALL) &&
1409 IC_RESULT(dic)->key == IC_RIGHT(ic)->key) {
1413 /* if shift by unknown amount then not */
1414 if ((dic->op == LEFT_OP || dic->op == RIGHT_OP) &&
1415 IC_RESULT(dic)->key == IC_RIGHT(ic)->key)
1418 /* if pointer get and size > 1 */
1419 if (POINTER_GET(dic) &&
1420 getSize(aggrToPtr(operandType(IC_LEFT(dic)),FALSE)) > 1)
1423 if (POINTER_SET(dic) &&
1424 getSize(aggrToPtr(operandType(IC_RESULT(dic)),FALSE)) > 1)
1427 /* if any three is a true symbol in far space */
1428 if (IC_RESULT(dic) &&
1429 IS_TRUE_SYMOP(IC_RESULT(dic)) &&
1430 isOperandInFarSpace(IC_RESULT(dic)))
1433 if (IC_RIGHT(dic) &&
1434 IS_TRUE_SYMOP(IC_RIGHT(dic)) &&
1435 isOperandInFarSpace(IC_RIGHT(dic)) &&
1436 !isOperandEqual(IC_RIGHT(dic),IC_RESULT(ic)))
1440 IS_TRUE_SYMOP(IC_LEFT(dic)) &&
1441 isOperandInFarSpace(IC_LEFT(dic)) &&
1442 !isOperandEqual(IC_LEFT(dic),IC_RESULT(ic)))
1445 if (isOperandEqual(IC_RIGHT(ic),IC_RESULT(dic))) {
1446 if ( (dic->op == LEFT_OP ||
1447 dic->op == RIGHT_OP ||
1449 IS_OP_LITERAL(IC_RIGHT(dic)))
1459 /*-----------------------------------------------------------------*/
1460 /* packRegsForAssign - register reduction for assignment */
1461 /*-----------------------------------------------------------------*/
1462 static int packRegsForAssign (iCode *ic,eBBlock *ebp)
1466 if (!IS_ITEMP(IC_RIGHT(ic)) ||
1467 OP_SYMBOL(IC_RIGHT(ic))->isind ||
1468 OP_LIVETO(IC_RIGHT(ic)) > ic->seq) {
1472 /* if the true symbol is defined in far space or on stack
1473 then we should not since this will increase register pressure */
1474 if (isOperandInFarSpace(IC_RESULT(ic))) {
1475 if ((dic = farSpacePackable(ic)))
1481 /* find the definition of iTempNN scanning backwards if we find a
1482 a use of the true symbol in before we find the definition then
1484 for ( dic = ic->prev ; dic ; dic = dic->prev) {
1486 /* if there is a function call and this is
1487 a parameter & not my parameter then don't pack it */
1488 if ( (dic->op == CALL || dic->op == PCALL) &&
1489 (OP_SYMBOL(IC_RESULT(ic))->_isparm &&
1490 !OP_SYMBOL(IC_RESULT(ic))->ismyparm)) {
1498 if (IS_TRUE_SYMOP(IC_RESULT(dic)) &&
1499 IS_OP_VOLATILE(IC_RESULT(dic))) {
1504 if (IS_SYMOP(IC_RESULT(dic)) &&
1505 IC_RESULT(dic)->key == IC_RIGHT(ic)->key) {
1506 if (POINTER_SET(dic))
1512 if (IS_SYMOP(IC_RIGHT(dic)) &&
1513 (IC_RIGHT(dic)->key == IC_RESULT(ic)->key ||
1514 IC_RIGHT(dic)->key == IC_RIGHT(ic)->key)) {
1519 if (IS_SYMOP(IC_LEFT(dic)) &&
1520 (IC_LEFT(dic)->key == IC_RESULT(ic)->key ||
1521 IC_LEFT(dic)->key == IC_RIGHT(ic)->key)) {
1526 if (POINTER_SET(dic) &&
1527 IC_RESULT(dic)->key == IC_RESULT(ic)->key ) {
1534 return 0 ; /* did not find */
1536 /* if the result is on stack or iaccess then it must be
1537 the same atleast one of the operands */
1538 if (OP_SYMBOL(IC_RESULT(ic))->onStack ||
1539 OP_SYMBOL(IC_RESULT(ic))->iaccess ) {
1541 /* the operation has only one symbol
1542 operator then we can pack */
1543 if ((IC_LEFT(dic) && !IS_SYMOP(IC_LEFT(dic))) ||
1544 (IC_RIGHT(dic) && !IS_SYMOP(IC_RIGHT(dic))))
1547 if (!((IC_LEFT(dic) &&
1548 IC_RESULT(ic)->key == IC_LEFT(dic)->key) ||
1550 IC_RESULT(ic)->key == IC_RIGHT(dic)->key)))
1554 /* found the definition */
1555 /* replace the result with the result of */
1556 /* this assignment and remove this assignment */
1557 IC_RESULT(dic) = IC_RESULT(ic) ;
1559 if (IS_ITEMP(IC_RESULT(dic)) && OP_SYMBOL(IC_RESULT(dic))->liveFrom > dic->seq) {
1560 OP_SYMBOL(IC_RESULT(dic))->liveFrom = dic->seq;
1562 /* delete from liverange table also
1563 delete from all the points inbetween and the new
1565 for ( sic = dic; sic != ic ; sic = sic->next ) {
1566 bitVectUnSetBit(sic->rlive,IC_RESULT(ic)->key);
1567 if (IS_ITEMP(IC_RESULT(dic)))
1568 bitVectSetBit(sic->rlive,IC_RESULT(dic)->key);
1571 remiCodeFromeBBlock(ebp,ic);
1572 hTabDeleteItem (&iCodehTab,ic->key,ic,DELETE_ITEM,NULL);
1573 OP_DEFS(IC_RESULT(dic)) = bitVectSetBit(OP_DEFS(IC_RESULT(dic)),dic->key);
1578 /*-----------------------------------------------------------------*/
1579 /* findAssignToSym : scanning backwards looks for first assig found*/
1580 /*-----------------------------------------------------------------*/
1581 static iCode *findAssignToSym (operand *op,iCode *ic)
1585 for (dic = ic->prev ; dic ; dic = dic->prev) {
1587 /* if definition by assignment */
1588 if (dic->op == '=' &&
1589 !POINTER_SET(dic) &&
1590 IC_RESULT(dic)->key == op->key
1591 /* && IS_TRUE_SYMOP(IC_RIGHT(dic)) */
1594 /* we are interested only if defined in far space */
1595 /* or in stack space in case of + & - */
1597 /* if assigned to a non-symbol then return
1599 if (!IS_SYMOP(IC_RIGHT(dic)))
1602 /* if the symbol is in far space then
1604 if (isOperandInFarSpace(IC_RIGHT(dic)))
1607 /* for + & - operations make sure that
1608 if it is on the stack it is the same
1609 as one of the three operands */
1610 if ((ic->op == '+' || ic->op == '-') &&
1611 OP_SYMBOL(IC_RIGHT(dic))->onStack) {
1613 if ( IC_RESULT(ic)->key != IC_RIGHT(dic)->key &&
1614 IC_LEFT(ic)->key != IC_RIGHT(dic)->key &&
1615 IC_RIGHT(ic)->key != IC_RIGHT(dic)->key)
1623 /* if we find an usage then we cannot delete it */
1624 if (IC_LEFT(dic) && IC_LEFT(dic)->key == op->key)
1627 if (IC_RIGHT(dic) && IC_RIGHT(dic)->key == op->key)
1630 if (POINTER_SET(dic) && IC_RESULT(dic)->key == op->key)
1634 /* now make sure that the right side of dic
1635 is not defined between ic & dic */
1637 iCode *sic = dic->next ;
1639 for (; sic != ic ; sic = sic->next)
1640 if (IC_RESULT(sic) &&
1641 IC_RESULT(sic)->key == IC_RIGHT(dic)->key)
1650 /*-----------------------------------------------------------------*/
1651 /* packRegsForSupport :- reduce some registers for support calls */
1652 /*-----------------------------------------------------------------*/
1653 static int packRegsForSupport (iCode *ic, eBBlock *ebp)
1656 /* for the left & right operand :- look to see if the
1657 left was assigned a true symbol in far space in that
1658 case replace them */
1659 if (IS_ITEMP(IC_LEFT(ic)) &&
1660 OP_SYMBOL(IC_LEFT(ic))->liveTo <= ic->seq) {
1661 iCode *dic = findAssignToSym(IC_LEFT(ic),ic);
1667 /* found it we need to remove it from the
1669 for ( sic = dic; sic != ic ; sic = sic->next )
1670 bitVectUnSetBit(sic->rlive,IC_LEFT(ic)->key);
1672 IC_LEFT(ic)->operand.symOperand =
1673 IC_RIGHT(dic)->operand.symOperand;
1674 IC_LEFT(ic)->key = IC_RIGHT(dic)->operand.symOperand->key;
1675 remiCodeFromeBBlock(ebp,dic);
1676 hTabDeleteItem (&iCodehTab,dic->key,dic,DELETE_ITEM,NULL);
1680 /* do the same for the right operand */
1683 IS_ITEMP(IC_RIGHT(ic)) &&
1684 OP_SYMBOL(IC_RIGHT(ic))->liveTo <= ic->seq) {
1685 iCode *dic = findAssignToSym(IC_RIGHT(ic),ic);
1691 /* if this is a subtraction & the result
1692 is a true symbol in far space then don't pack */
1693 if (ic->op == '-' && IS_TRUE_SYMOP(IC_RESULT(dic))) {
1694 link *etype =getSpec(operandType(IC_RESULT(dic)));
1695 if (IN_FARSPACE(SPEC_OCLS(etype)))
1698 /* found it we need to remove it from the
1700 for ( sic = dic; sic != ic ; sic = sic->next )
1701 bitVectUnSetBit(sic->rlive,IC_RIGHT(ic)->key);
1703 IC_RIGHT(ic)->operand.symOperand =
1704 IC_RIGHT(dic)->operand.symOperand;
1705 IC_RIGHT(ic)->key = IC_RIGHT(dic)->operand.symOperand->key;
1707 remiCodeFromeBBlock(ebp,dic);
1708 hTabDeleteItem (&iCodehTab,dic->key,dic,DELETE_ITEM,NULL);
1715 #define IS_OP_RUONLY(x) (x && IS_SYMOP(x) && OP_SYMBOL(x)->ruonly)
1718 /*-----------------------------------------------------------------*/
1719 /* packRegsForOneuse : - will reduce some registers for single Use */
1720 /*-----------------------------------------------------------------*/
1721 static iCode *packRegsForOneuse (iCode *ic, operand *op , eBBlock *ebp)
1725 /* I can't figure out how to make this safe yet. */
1734 /* if returning a literal then do nothing */
1738 /* only upto 2 bytes since we cannot predict
1739 the usage of b, & acc */
1740 if (getSize(operandType(op)) > (fReturnSize_390 - 2) &&
1747 /* this routine will mark the a symbol as used in one
1748 instruction use only && if the defintion is local
1749 (ie. within the basic block) && has only one definition &&
1750 that definiion is either a return value from a
1751 function or does not contain any variables in
1753 uses = bitVectCopy(OP_USES(op));
1754 bitVectUnSetBit(uses,ic->key); /* take away this iCode */
1755 if (!bitVectIsZero(uses)) /* has other uses */
1758 /* if it has only one defintion */
1759 if (bitVectnBitsOn(OP_DEFS(op)) > 1)
1760 return NULL ; /* has more than one definition */
1762 /* get the that definition */
1764 hTabItemWithKey(iCodehTab,
1765 bitVectFirstBit(OP_DEFS(op)))))
1768 /* found the definition now check if it is local */
1769 if (dic->seq < ebp->fSeq ||
1770 dic->seq > ebp->lSeq)
1771 return NULL ; /* non-local */
1773 /* now check if it is the return from
1775 if (dic->op == CALL || dic->op == PCALL ) {
1776 if (ic->op != SEND && ic->op != RETURN) {
1777 OP_SYMBOL(op)->ruonly = 1;
1784 /* otherwise check that the definition does
1785 not contain any symbols in far space */
1786 if (isOperandInFarSpace(IC_LEFT(dic)) ||
1787 isOperandInFarSpace(IC_RIGHT(dic)) ||
1788 IS_OP_RUONLY(IC_LEFT(ic)) ||
1789 IS_OP_RUONLY(IC_RIGHT(ic)) ) {
1793 /* if pointer set then make sure the pointer
1795 if (POINTER_SET(dic) &&
1796 !IS_DATA_PTR(aggrToPtr(operandType(IC_RESULT(dic)),FALSE)))
1799 if (POINTER_GET(dic) &&
1800 !IS_DATA_PTR(aggrToPtr(operandType(IC_LEFT(dic)),FALSE)))
1805 /* also make sure the intervenening instructions
1806 don't have any thing in far space */
1807 for (dic = dic->next ; dic && dic != ic ; dic = dic->next) {
1809 /* if there is an intervening function call then no */
1810 if (dic->op == CALL || dic->op == PCALL)
1812 /* if pointer set then make sure the pointer
1814 if (POINTER_SET(dic) &&
1815 !IS_DATA_PTR(aggrToPtr(operandType(IC_RESULT(dic)),FALSE)))
1818 if (POINTER_GET(dic) &&
1819 !IS_DATA_PTR(aggrToPtr(operandType(IC_LEFT(dic)),FALSE)))
1822 /* if address of & the result is remat the okay */
1823 if (dic->op == ADDRESS_OF &&
1824 OP_SYMBOL(IC_RESULT(dic))->remat)
1827 /* if operand has size of three or more & this
1828 operation is a '*','/' or '%' then 'b' may
1830 if (( dic->op == '%' || dic->op == '/' || dic->op == '*') &&
1831 getSize(operandType(op)) >= 3)
1834 /* if left or right or result is in far space */
1835 if (isOperandInFarSpace(IC_LEFT(dic)) ||
1836 isOperandInFarSpace(IC_RIGHT(dic)) ||
1837 isOperandInFarSpace(IC_RESULT(dic)) ||
1838 IS_OP_RUONLY(IC_LEFT(dic)) ||
1839 IS_OP_RUONLY(IC_RIGHT(dic)) ||
1840 IS_OP_RUONLY(IC_RESULT(dic)) ) {
1845 OP_SYMBOL(op)->ruonly = 1;
1850 /*-----------------------------------------------------------------*/
1851 /* isBitwiseOptimizable - requirements of JEAN LOUIS VERN */
1852 /*-----------------------------------------------------------------*/
1853 static bool isBitwiseOptimizable (iCode *ic)
1855 link *ltype = getSpec(operandType(IC_LEFT(ic)));
1856 link *rtype = getSpec(operandType(IC_RIGHT(ic)));
1858 /* bitwise operations are considered optimizable
1859 under the following conditions (Jean-Louis VERN)
1871 if ( IS_LITERAL(rtype) ||
1872 (IS_BITVAR(ltype) && IN_BITSPACE(SPEC_OCLS(ltype))))
1878 /*-----------------------------------------------------------------*/
1879 /* packRegsForAccUse - pack registers for acc use */
1880 /*-----------------------------------------------------------------*/
1881 static void packRegsForAccUse (iCode *ic)
1885 /* if + or - then it has to be one byte result */
1886 if ((ic->op == '+' || ic->op == '-')
1887 && getSize(operandType(IC_RESULT(ic))) > 1)
1890 /* if shift operation make sure right side is not a literal */
1891 if (ic->op == RIGHT_OP &&
1892 ( isOperandLiteral(IC_RIGHT(ic)) ||
1893 getSize(operandType(IC_RESULT(ic))) > 1))
1896 if (ic->op == LEFT_OP &&
1897 ( isOperandLiteral(IC_RIGHT(ic)) ||
1898 getSize(operandType(IC_RESULT(ic))) > 1))
1901 if (IS_BITWISE_OP(ic) &&
1902 getSize(operandType(IC_RESULT(ic))) > 1)
1906 /* has only one definition */
1907 if (bitVectnBitsOn(OP_DEFS(IC_RESULT(ic))) > 1)
1910 /* has only one use */
1911 if (bitVectnBitsOn(OP_USES(IC_RESULT(ic))) > 1)
1914 /* and the usage immediately follows this iCode */
1915 if (!(uic = hTabItemWithKey(iCodehTab,
1916 bitVectFirstBit(OP_USES(IC_RESULT(ic))))))
1919 if (ic->next != uic)
1922 /* if it is a conditional branch then we definitely can */
1923 if (uic->op == IFX )
1926 if ( uic->op == JUMPTABLE )
1929 /* if the usage is not is an assignment
1930 or an arithmetic / bitwise / shift operation then not */
1931 if (POINTER_SET(uic) &&
1932 getSize(aggrToPtr(operandType(IC_RESULT(uic)),FALSE)) > 1)
1935 if (uic->op != '=' &&
1936 !IS_ARITHMETIC_OP(uic) &&
1937 !IS_BITWISE_OP(uic) &&
1938 uic->op != LEFT_OP &&
1939 uic->op != RIGHT_OP )
1942 /* if used in ^ operation then make sure right is not a
1944 if (uic->op == '^' && isOperandLiteral(IC_RIGHT(uic)))
1947 /* if shift operation make sure right side is not a literal */
1948 if (uic->op == RIGHT_OP &&
1949 ( isOperandLiteral(IC_RIGHT(uic)) ||
1950 getSize(operandType(IC_RESULT(uic))) > 1))
1953 if (uic->op == LEFT_OP &&
1954 ( isOperandLiteral(IC_RIGHT(uic)) ||
1955 getSize(operandType(IC_RESULT(uic))) > 1))
1958 /* make sure that the result of this icode is not on the
1959 stack, since acc is used to compute stack offset */
1960 if (IS_TRUE_SYMOP(IC_RESULT(uic)) &&
1961 OP_SYMBOL(IC_RESULT(uic))->onStack)
1964 /* if either one of them in far space then we cannot */
1965 if ((IS_TRUE_SYMOP(IC_LEFT(uic)) &&
1966 isOperandInFarSpace(IC_LEFT(uic))) ||
1967 (IS_TRUE_SYMOP(IC_RIGHT(uic)) &&
1968 isOperandInFarSpace(IC_RIGHT(uic))))
1971 /* if the usage has only one operand then we can */
1972 if (IC_LEFT(uic) == NULL ||
1973 IC_RIGHT(uic) == NULL)
1976 /* make sure this is on the left side if not
1977 a '+' since '+' is commutative */
1978 if (ic->op != '+' &&
1979 IC_LEFT(uic)->key != IC_RESULT(ic)->key)
1982 /* if one of them is a literal then we can */
1983 if ((IC_LEFT(uic) && IS_OP_LITERAL(IC_LEFT(uic))) ||
1984 (IC_RIGHT(uic) && IS_OP_LITERAL(IC_RIGHT(uic)))) {
1985 OP_SYMBOL(IC_RESULT(ic))->accuse = 1;
1989 /* if the other one is not on stack then we can */
1990 if (IC_LEFT(uic)->key == IC_RESULT(ic)->key &&
1991 (IS_ITEMP(IC_RIGHT(uic)) ||
1992 (IS_TRUE_SYMOP(IC_RIGHT(uic)) &&
1993 !OP_SYMBOL(IC_RIGHT(uic))->onStack)))
1996 if (IC_RIGHT(uic)->key == IC_RESULT(ic)->key &&
1997 (IS_ITEMP(IC_LEFT(uic)) ||
1998 (IS_TRUE_SYMOP(IC_LEFT(uic)) &&
1999 !OP_SYMBOL(IC_LEFT(uic))->onStack)))
2005 OP_SYMBOL(IC_RESULT(ic))->accuse = 1;
2010 /*-----------------------------------------------------------------*/
2011 /* packForPush - hueristics to reduce iCode for pushing */
2012 /*-----------------------------------------------------------------*/
2013 static void packForPush(iCode *ic, eBBlock *ebp)
2017 if (ic->op != IPUSH || !IS_ITEMP(IC_LEFT(ic)))
2020 /* must have only definition & one usage */
2021 if (bitVectnBitsOn(OP_DEFS(IC_LEFT(ic))) != 1 ||
2022 bitVectnBitsOn(OP_USES(IC_LEFT(ic))) != 1 )
2025 /* find the definition */
2026 if (!(dic = hTabItemWithKey(iCodehTab,
2027 bitVectFirstBit(OP_DEFS(IC_LEFT(ic))))))
2030 if (dic->op != '=' || POINTER_SET(dic))
2033 /* we now we know that it has one & only one def & use
2034 and the that the definition is an assignment */
2035 IC_LEFT(ic) = IC_RIGHT(dic);
2037 remiCodeFromeBBlock(ebp,dic);
2038 hTabDeleteItem (&iCodehTab,dic->key,dic,DELETE_ITEM,NULL);
2041 /*-----------------------------------------------------------------*/
2042 /* packRegisters - does some transformations to reduce register */
2044 /*-----------------------------------------------------------------*/
2045 static void packRegisters (eBBlock *ebp)
2054 /* look for assignments of the form */
2055 /* iTempNN = TRueSym (someoperation) SomeOperand */
2057 /* TrueSym := iTempNN:1 */
2058 for ( ic = ebp->sch ; ic ; ic = ic->next ) {
2061 /* find assignment of the form TrueSym := iTempNN:1 */
2062 if (ic->op == '=' && !POINTER_SET(ic))
2063 change += packRegsForAssign(ic,ebp);
2070 for ( ic = ebp->sch ; ic ; ic = ic->next ) {
2072 /* if this is an itemp & result of a address of a true sym
2073 then mark this as rematerialisable */
2074 if (ic->op == ADDRESS_OF &&
2075 IS_ITEMP(IC_RESULT(ic)) &&
2076 IS_TRUE_SYMOP(IC_LEFT(ic)) &&
2077 bitVectnBitsOn(OP_DEFS(IC_RESULT(ic))) == 1 &&
2078 !OP_SYMBOL(IC_LEFT(ic))->onStack ) {
2080 OP_SYMBOL(IC_RESULT(ic))->remat = 1;
2081 OP_SYMBOL(IC_RESULT(ic))->rematiCode = ic;
2082 OP_SYMBOL(IC_RESULT(ic))->usl.spillLoc = NULL;
2086 /* if straight assignment then carry remat flag if
2087 this is the only definition */
2088 if (ic->op == '=' &&
2090 IS_SYMOP(IC_RIGHT(ic)) &&
2091 OP_SYMBOL(IC_RIGHT(ic))->remat &&
2092 bitVectnBitsOn(OP_SYMBOL(IC_RESULT(ic))->defs) <= 1) {
2094 OP_SYMBOL(IC_RESULT(ic))->remat =
2095 OP_SYMBOL(IC_RIGHT(ic))->remat;
2096 OP_SYMBOL(IC_RESULT(ic))->rematiCode =
2097 OP_SYMBOL(IC_RIGHT(ic))->rematiCode ;
2100 /* if this is a +/- operation with a rematerizable
2101 then mark this as rematerializable as well */
2102 if ((ic->op == '+' || ic->op == '-') &&
2103 (IS_SYMOP(IC_LEFT(ic)) &&
2104 IS_ITEMP(IC_RESULT(ic)) &&
2105 OP_SYMBOL(IC_LEFT(ic))->remat &&
2106 bitVectnBitsOn(OP_DEFS(IC_RESULT(ic))) == 1 &&
2107 IS_OP_LITERAL(IC_RIGHT(ic))) ) {
2109 //int i = operandLitValue(IC_RIGHT(ic));
2110 OP_SYMBOL(IC_RESULT(ic))->remat = 1;
2111 OP_SYMBOL(IC_RESULT(ic))->rematiCode = ic;
2112 OP_SYMBOL(IC_RESULT(ic))->usl.spillLoc = NULL;
2115 /* mark the pointer usages */
2116 if (POINTER_SET(ic))
2117 OP_SYMBOL(IC_RESULT(ic))->uptr = 1;
2119 if (POINTER_GET(ic))
2120 OP_SYMBOL(IC_LEFT(ic))->uptr = 1;
2122 if (!SKIP_IC2(ic)) {
2123 /* if we are using a symbol on the stack
2124 then we should say ds390_ptrRegReq */
2125 if (ic->op == IFX && IS_SYMOP(IC_COND(ic)))
2126 ds390_ptrRegReq += ((OP_SYMBOL(IC_COND(ic))->onStack ||
2127 OP_SYMBOL(IC_COND(ic))->iaccess) ? 1 : 0);
2129 if (ic->op == JUMPTABLE && IS_SYMOP(IC_JTCOND(ic)))
2130 ds390_ptrRegReq += ((OP_SYMBOL(IC_JTCOND(ic))->onStack ||
2131 OP_SYMBOL(IC_JTCOND(ic))->iaccess) ? 1 : 0);
2133 if (IS_SYMOP(IC_LEFT(ic)))
2134 ds390_ptrRegReq += ((OP_SYMBOL(IC_LEFT(ic))->onStack ||
2135 OP_SYMBOL(IC_LEFT(ic))->iaccess) ? 1 : 0);
2136 if (IS_SYMOP(IC_RIGHT(ic)))
2137 ds390_ptrRegReq += ((OP_SYMBOL(IC_RIGHT(ic))->onStack ||
2138 OP_SYMBOL(IC_RIGHT(ic))->iaccess) ? 1 : 0);
2139 if (IS_SYMOP(IC_RESULT(ic)))
2140 ds390_ptrRegReq += ((OP_SYMBOL(IC_RESULT(ic))->onStack ||
2141 OP_SYMBOL(IC_RESULT(ic))->iaccess) ? 1 : 0);
2145 /* if the condition of an if instruction
2146 is defined in the previous instruction then
2147 mark the itemp as a conditional */
2148 if ((IS_CONDITIONAL(ic) ||
2149 ( ( ic->op == BITWISEAND ||
2152 isBitwiseOptimizable(ic))) &&
2153 ic->next && ic->next->op == IFX &&
2154 isOperandEqual(IC_RESULT(ic),IC_COND(ic->next)) &&
2155 OP_SYMBOL(IC_RESULT(ic))->liveTo <= ic->next->seq) {
2157 OP_SYMBOL(IC_RESULT(ic))->regType = REG_CND;
2161 /* reduce for support function calls */
2162 if (ic->supportRtn || ic->op == '+' || ic->op == '-' )
2163 packRegsForSupport (ic,ebp);
2165 /* some cases the redundant moves can
2166 can be eliminated for return statements */
2167 if ((ic->op == RETURN || ic->op == SEND) &&
2168 !isOperandInFarSpace(IC_LEFT(ic)) &&
2170 packRegsForOneuse (ic,IC_LEFT(ic),ebp);
2172 /* if pointer set & left has a size more than
2173 one and right is not in far space */
2174 if (POINTER_SET(ic) &&
2175 !isOperandInFarSpace(IC_RIGHT(ic)) &&
2176 !OP_SYMBOL(IC_RESULT(ic))->remat &&
2177 !IS_OP_RUONLY(IC_RIGHT(ic)) &&
2178 getSize(aggrToPtr(operandType(IC_RESULT(ic)),FALSE)) > 1 )
2180 packRegsForOneuse (ic,IC_RESULT(ic),ebp);
2182 /* if pointer get */
2183 if (POINTER_GET(ic) &&
2184 !isOperandInFarSpace(IC_RESULT(ic))&&
2185 !OP_SYMBOL(IC_LEFT(ic))->remat &&
2186 !IS_OP_RUONLY(IC_RESULT(ic)) &&
2187 getSize(aggrToPtr(operandType(IC_LEFT(ic)),FALSE)) > 1 )
2189 packRegsForOneuse (ic,IC_LEFT(ic),ebp);
2192 /* if this is cast for intergral promotion then
2193 check if only use of the definition of the
2194 operand being casted/ if yes then replace
2195 the result of that arithmetic operation with
2196 this result and get rid of the cast */
2197 if (ic->op == CAST) {
2198 link *fromType = operandType(IC_RIGHT(ic));
2199 link *toType = operandType(IC_LEFT(ic));
2201 if (IS_INTEGRAL(fromType) && IS_INTEGRAL(toType) &&
2202 getSize(fromType) != getSize(toType) &&
2203 SPEC_USIGN(fromType) == SPEC_USIGN(toType)) {
2205 iCode *dic = packRegsForOneuse(ic,IC_RIGHT(ic),ebp);
2207 if (IS_ARITHMETIC_OP(dic)) {
2208 IC_RESULT(dic) = IC_RESULT(ic);
2209 remiCodeFromeBBlock(ebp,ic);
2210 hTabDeleteItem (&iCodehTab,ic->key,ic,DELETE_ITEM,NULL);
2211 OP_DEFS(IC_RESULT(dic)) = bitVectSetBit(OP_DEFS(IC_RESULT(dic)),dic->key);
2214 OP_SYMBOL(IC_RIGHT(ic))->ruonly = 0;
2218 /* if the type from and type to are the same
2219 then if this is the only use then packit */
2220 if (checkType(operandType(IC_RIGHT(ic)),
2221 operandType(IC_LEFT(ic))) == 1) {
2222 iCode *dic = packRegsForOneuse (ic,IC_RIGHT(ic),ebp);
2224 IC_RESULT(dic) = IC_RESULT(ic);
2225 remiCodeFromeBBlock(ebp,ic);
2226 hTabDeleteItem (&iCodehTab,ic->key,ic,DELETE_ITEM,NULL);
2227 OP_DEFS(IC_RESULT(dic)) = bitVectSetBit(OP_DEFS(IC_RESULT(dic)),dic->key);
2235 iTempNN := (some variable in farspace) V1
2240 if (ic->op == IPUSH ) {
2241 packForPush(ic,ebp);
2245 /* pack registers for accumulator use, when the
2246 result of an arithmetic or bit wise operation
2247 has only one use, that use is immediately following
2248 the defintion and the using iCode has only one
2249 operand or has two operands but one is literal &
2250 the result of that operation is not on stack then
2251 we can leave the result of this operation in acc:b
2253 if ((IS_ARITHMETIC_OP(ic)
2255 || IS_BITWISE_OP(ic)
2257 || ic->op == LEFT_OP || ic->op == RIGHT_OP
2260 IS_ITEMP(IC_RESULT(ic)) &&
2261 getSize(operandType(IC_RESULT(ic))) <= 2)
2263 packRegsForAccUse (ic);
2268 /*-----------------------------------------------------------------*/
2269 /* assignRegisters - assigns registers to each live range as need */
2270 /*-----------------------------------------------------------------*/
2271 void ds390_assignRegisters (eBBlock **ebbs, int count)
2276 setToNull((void *)&_G.funcrUsed);
2277 ds390_ptrRegReq = _G.stackExtend = _G.dataExtend = 0;
2278 /* if not register extentions then reduce number
2280 if (options.regExtend)
2285 /* change assignments this will remove some
2286 live ranges reducing some register pressure */
2287 for (i = 0 ; i < count ;i++ )
2288 packRegisters (ebbs[i]);
2290 if (options.dump_pack)
2291 dumpEbbsToFileExt(".dumppack",ebbs,count);
2293 /* first determine for each live range the number of
2294 registers & the type of registers required for each */
2297 /* and serially allocate registers */
2298 serialRegAssign(ebbs,count);
2300 /* if stack was extended then tell the user */
2301 if (_G.stackExtend) {
2302 /* werror(W_TOOMANY_SPILS,"stack", */
2303 /* _G.stackExtend,currFunc->name,""); */
2304 _G.stackExtend = 0 ;
2307 if (_G.dataExtend) {
2308 /* werror(W_TOOMANY_SPILS,"data space", */
2309 /* _G.dataExtend,currFunc->name,""); */
2313 /* after that create the register mask
2314 for each of the instruction */
2315 createRegMask (ebbs,count);
2317 /* redo that offsets for stacked automatic variables */
2318 redoStackOffsets ();
2320 if (options.dump_rassgn)
2321 dumpEbbsToFileExt(".dumprassgn",ebbs,count);
2323 /* do the overlaysegment stuff SDCCmem.c */
2324 doOverlays(ebbs,count);
2326 /* now get back the chain */
2327 ic = iCodeLabelOptimize(iCodeFromeBBlock (ebbs,count));
2332 /* free up any _G.stackSpil locations allocated */
2333 applyToSet(_G.stackSpil,deallocStackSpil);
2335 setToNull((void **)&_G.stackSpil);
2336 setToNull((void **)&_G.spiltSet);
2337 /* mark all registers as free */