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) && IS_SYMOP(IC_LEFT(ic))
1080 && getSize(OP_SYMBOL(IC_LEFT(ic))->type)
1086 /* else we assign registers to it */
1087 _G.regAssigned = bitVectSetBit(_G.regAssigned,sym->key);
1089 for (j = 0 ; j < sym->nRegs ;j++ ) {
1090 if (sym->regType == REG_PTR)
1091 sym->regs[j] = getRegPtr(ic,ebbs[i],sym);
1093 sym->regs[j] = getRegGpr(ic,ebbs[i],sym);
1095 /* if the allocation falied which means
1096 this was spilt then break */
1100 /* if it shares registers with operands make sure
1101 that they are in the same position */
1102 if (IC_LEFT(ic) && IS_SYMOP(IC_LEFT(ic)) &&
1103 OP_SYMBOL(IC_LEFT(ic))->nRegs && ic->op != '=')
1104 positionRegs(OP_SYMBOL(IC_RESULT(ic)),
1105 OP_SYMBOL(IC_LEFT(ic)),ic->lineno);
1106 /* do the same for the right operand */
1107 if (IC_RIGHT(ic) && IS_SYMOP(IC_RIGHT(ic)) &&
1108 OP_SYMBOL(IC_RIGHT(ic))->nRegs)
1109 positionRegs(OP_SYMBOL(IC_RESULT(ic)),
1110 OP_SYMBOL(IC_RIGHT(ic)),ic->lineno);
1122 /*-----------------------------------------------------------------*/
1123 /* rUmaskForOp :- returns register mask for an operand */
1124 /*-----------------------------------------------------------------*/
1125 static bitVect *rUmaskForOp (operand *op)
1131 /* only temporaries are assigned registers */
1135 sym = OP_SYMBOL(op);
1137 /* if spilt or no registers assigned to it
1139 if (sym->isspilt || !sym->nRegs)
1142 rumask = newBitVect(ds390_nRegs);
1144 for (j = 0; j < sym->nRegs; j++) {
1145 rumask = bitVectSetBit(rumask,
1146 sym->regs[j]->rIdx);
1152 /*-----------------------------------------------------------------*/
1153 /* regsUsedIniCode :- returns bit vector of registers used in iCode*/
1154 /*-----------------------------------------------------------------*/
1155 static bitVect *regsUsedIniCode (iCode *ic)
1157 bitVect *rmask = newBitVect(ds390_nRegs);
1159 /* do the special cases first */
1160 if (ic->op == IFX ) {
1161 rmask = bitVectUnion(rmask,
1162 rUmaskForOp(IC_COND(ic)));
1166 /* for the jumptable */
1167 if (ic->op == JUMPTABLE) {
1168 rmask = bitVectUnion(rmask,
1169 rUmaskForOp(IC_JTCOND(ic)));
1174 /* of all other cases */
1176 rmask = bitVectUnion(rmask,
1177 rUmaskForOp(IC_LEFT(ic)));
1181 rmask = bitVectUnion(rmask,
1182 rUmaskForOp(IC_RIGHT(ic)));
1185 rmask = bitVectUnion(rmask,
1186 rUmaskForOp(IC_RESULT(ic)));
1192 /*-----------------------------------------------------------------*/
1193 /* createRegMask - for each instruction will determine the regsUsed*/
1194 /*-----------------------------------------------------------------*/
1195 static void createRegMask (eBBlock **ebbs, int count)
1199 /* for all blocks */
1200 for (i = 0; i < count ; i++ ) {
1203 if ( ebbs[i]->noPath &&
1204 ( ebbs[i]->entryLabel != entryLabel &&
1205 ebbs[i]->entryLabel != returnLabel ))
1208 /* for all instructions */
1209 for ( ic = ebbs[i]->sch ; ic ; ic = ic->next ) {
1213 if (SKIP_IC2(ic) || !ic->rlive)
1216 /* first mark the registers used in this
1218 ic->rUsed = regsUsedIniCode(ic);
1219 _G.funcrUsed = bitVectUnion(_G.funcrUsed,ic->rUsed);
1221 /* now create the register mask for those
1222 registers that are in use : this is a
1223 super set of ic->rUsed */
1224 ic->rMask = newBitVect(ds390_nRegs+1);
1226 /* for all live Ranges alive at this point */
1227 for (j = 1; j < ic->rlive->size; j++ ) {
1231 /* if not alive then continue */
1232 if (!bitVectBitValue(ic->rlive,j))
1235 /* find the live range we are interested in */
1236 if (!(sym = hTabItemWithKey(liveRanges,j))) {
1237 werror (E_INTERNAL_ERROR,__FILE__,__LINE__,
1238 "createRegMask cannot find live range");
1242 /* if no register assigned to it */
1243 if (!sym->nRegs || sym->isspilt)
1246 /* for all the registers allocated to it */
1247 for (k = 0 ; k < sym->nRegs ;k++)
1250 bitVectSetBit(ic->rMask,sym->regs[k]->rIdx);
1256 /*-----------------------------------------------------------------*/
1257 /* rematStr - returns the rematerialized string for a remat var */
1258 /*-----------------------------------------------------------------*/
1259 static char *rematStr (symbol *sym)
1262 iCode *ic = sym->rematiCode;
1266 /* if plus or minus print the right hand side */
1267 if (ic->op == '+' || ic->op == '-') {
1268 sprintf(s,"0x%04x %c ",(int) operandLitValue(IC_RIGHT(ic)),
1271 ic = OP_SYMBOL(IC_LEFT(ic))->rematiCode;
1275 /* we reached the end */
1276 sprintf(s,"%s",OP_SYMBOL(IC_LEFT(ic))->rname);
1283 /*-----------------------------------------------------------------*/
1284 /* regTypeNum - computes the type & number of registers required */
1285 /*-----------------------------------------------------------------*/
1286 static void regTypeNum ()
1292 /* for each live range do */
1293 for ( sym = hTabFirstItem(liveRanges,&k); sym ;
1294 sym = hTabNextItem(liveRanges,&k)) {
1296 /* if used zero times then no registers needed */
1297 if ((sym->liveTo - sym->liveFrom) == 0)
1301 /* if the live range is a temporary */
1304 /* if the type is marked as a conditional */
1305 if (sym->regType == REG_CND)
1308 /* if used in return only then we don't
1310 if (sym->ruonly || sym->accuse) {
1311 if (IS_AGGREGATE(sym->type) || sym->isptr)
1312 sym->type = aggrToPtr(sym->type,FALSE);
1316 /* if the symbol has only one definition &
1317 that definition is a get_pointer and the
1318 pointer we are getting is rematerializable and
1321 if (bitVectnBitsOn(sym->defs) == 1 &&
1322 (ic = hTabItemWithKey(iCodehTab,
1323 bitVectFirstBit(sym->defs))) &&
1325 !IS_BITVAR(sym->etype)) {
1328 /* if remat in data space */
1329 if (OP_SYMBOL(IC_LEFT(ic))->remat &&
1331 DCL_TYPE(aggrToPtr(sym->type,FALSE)) == POINTER) {
1333 /* create a psuedo symbol & force a spil */
1334 symbol *psym = newSymbol(rematStr(OP_SYMBOL(IC_LEFT(ic))),1);
1335 psym->type = sym->type;
1336 psym->etype = sym->etype;
1337 strcpy(psym->rname,psym->name);
1339 sym->usl.spillLoc = psym;
1343 /* if in data space or idata space then try to
1344 allocate pointer register */
1348 /* if not then we require registers */
1349 sym->nRegs = ((IS_AGGREGATE(sym->type) || sym->isptr ) ?
1350 getSize(sym->type = aggrToPtr(sym->type,FALSE)) :
1351 getSize(sym->type));
1353 if (sym->nRegs > 4) {
1354 fprintf(stderr,"allocated more than 4 or 0 registers for type ");
1355 printTypeChain(sym->type,stderr);fprintf(stderr,"\n");
1358 /* determine the type of register required */
1359 if (sym->nRegs == 1 &&
1360 IS_PTR(sym->type) &&
1362 sym->regType = REG_PTR ;
1364 sym->regType = REG_GPR ;
1367 /* for the first run we don't provide */
1368 /* registers for true symbols we will */
1369 /* see how things go */
1375 /*-----------------------------------------------------------------*/
1376 /* freeAllRegs - mark all registers as free */
1377 /*-----------------------------------------------------------------*/
1378 static void freeAllRegs()
1382 for (i=0;i< ds390_nRegs;i++ )
1383 regs390[i].isFree = 1;
1386 /*-----------------------------------------------------------------*/
1387 /* deallocStackSpil - this will set the stack pointer back */
1388 /*-----------------------------------------------------------------*/
1389 static DEFSETFUNC(deallocStackSpil)
1397 /*-----------------------------------------------------------------*/
1398 /* farSpacePackable - returns the packable icode for far variables */
1399 /*-----------------------------------------------------------------*/
1400 static iCode *farSpacePackable (iCode *ic)
1404 /* go thru till we find a definition for the
1405 symbol on the right */
1406 for ( dic = ic->prev ; dic ; dic = dic->prev) {
1408 /* if the definition is a call then no */
1409 if ((dic->op == CALL || dic->op == PCALL) &&
1410 IC_RESULT(dic)->key == IC_RIGHT(ic)->key) {
1414 /* if shift by unknown amount then not */
1415 if ((dic->op == LEFT_OP || dic->op == RIGHT_OP) &&
1416 IC_RESULT(dic)->key == IC_RIGHT(ic)->key)
1419 /* if pointer get and size > 1 */
1420 if (POINTER_GET(dic) &&
1421 getSize(aggrToPtr(operandType(IC_LEFT(dic)),FALSE)) > 1)
1424 if (POINTER_SET(dic) &&
1425 getSize(aggrToPtr(operandType(IC_RESULT(dic)),FALSE)) > 1)
1428 /* if any three is a true symbol in far space */
1429 if (IC_RESULT(dic) &&
1430 IS_TRUE_SYMOP(IC_RESULT(dic)) &&
1431 isOperandInFarSpace(IC_RESULT(dic)))
1434 if (IC_RIGHT(dic) &&
1435 IS_TRUE_SYMOP(IC_RIGHT(dic)) &&
1436 isOperandInFarSpace(IC_RIGHT(dic)) &&
1437 !isOperandEqual(IC_RIGHT(dic),IC_RESULT(ic)))
1441 IS_TRUE_SYMOP(IC_LEFT(dic)) &&
1442 isOperandInFarSpace(IC_LEFT(dic)) &&
1443 !isOperandEqual(IC_LEFT(dic),IC_RESULT(ic)))
1446 if (isOperandEqual(IC_RIGHT(ic),IC_RESULT(dic))) {
1447 if ( (dic->op == LEFT_OP ||
1448 dic->op == RIGHT_OP ||
1450 IS_OP_LITERAL(IC_RIGHT(dic)))
1460 /*-----------------------------------------------------------------*/
1461 /* packRegsForAssign - register reduction for assignment */
1462 /*-----------------------------------------------------------------*/
1463 static int packRegsForAssign (iCode *ic,eBBlock *ebp)
1467 if (!IS_ITEMP(IC_RIGHT(ic)) ||
1468 OP_SYMBOL(IC_RIGHT(ic))->isind ||
1469 OP_LIVETO(IC_RIGHT(ic)) > ic->seq) {
1473 /* if the true symbol is defined in far space or on stack
1474 then we should not since this will increase register pressure */
1475 if (isOperandInFarSpace(IC_RESULT(ic))) {
1476 if ((dic = farSpacePackable(ic)))
1482 /* find the definition of iTempNN scanning backwards if we find a
1483 a use of the true symbol in before we find the definition then
1485 for ( dic = ic->prev ; dic ; dic = dic->prev) {
1487 /* if there is a function call and this is
1488 a parameter & not my parameter then don't pack it */
1489 if ( (dic->op == CALL || dic->op == PCALL) &&
1490 (OP_SYMBOL(IC_RESULT(ic))->_isparm &&
1491 !OP_SYMBOL(IC_RESULT(ic))->ismyparm)) {
1499 if (IS_TRUE_SYMOP(IC_RESULT(dic)) &&
1500 IS_OP_VOLATILE(IC_RESULT(dic))) {
1505 if (IS_SYMOP(IC_RESULT(dic)) &&
1506 IC_RESULT(dic)->key == IC_RIGHT(ic)->key) {
1507 if (POINTER_SET(dic))
1513 if (IS_SYMOP(IC_RIGHT(dic)) &&
1514 (IC_RIGHT(dic)->key == IC_RESULT(ic)->key ||
1515 IC_RIGHT(dic)->key == IC_RIGHT(ic)->key)) {
1520 if (IS_SYMOP(IC_LEFT(dic)) &&
1521 (IC_LEFT(dic)->key == IC_RESULT(ic)->key ||
1522 IC_LEFT(dic)->key == IC_RIGHT(ic)->key)) {
1527 if (POINTER_SET(dic) &&
1528 IC_RESULT(dic)->key == IC_RESULT(ic)->key ) {
1535 return 0 ; /* did not find */
1537 /* if the result is on stack or iaccess then it must be
1538 the same atleast one of the operands */
1539 if (OP_SYMBOL(IC_RESULT(ic))->onStack ||
1540 OP_SYMBOL(IC_RESULT(ic))->iaccess ) {
1542 /* the operation has only one symbol
1543 operator then we can pack */
1544 if ((IC_LEFT(dic) && !IS_SYMOP(IC_LEFT(dic))) ||
1545 (IC_RIGHT(dic) && !IS_SYMOP(IC_RIGHT(dic))))
1548 if (!((IC_LEFT(dic) &&
1549 IC_RESULT(ic)->key == IC_LEFT(dic)->key) ||
1551 IC_RESULT(ic)->key == IC_RIGHT(dic)->key)))
1555 /* found the definition */
1556 /* replace the result with the result of */
1557 /* this assignment and remove this assignment */
1558 IC_RESULT(dic) = IC_RESULT(ic) ;
1560 if (IS_ITEMP(IC_RESULT(dic)) && OP_SYMBOL(IC_RESULT(dic))->liveFrom > dic->seq) {
1561 OP_SYMBOL(IC_RESULT(dic))->liveFrom = dic->seq;
1563 /* delete from liverange table also
1564 delete from all the points inbetween and the new
1566 for ( sic = dic; sic != ic ; sic = sic->next ) {
1567 bitVectUnSetBit(sic->rlive,IC_RESULT(ic)->key);
1568 if (IS_ITEMP(IC_RESULT(dic)))
1569 bitVectSetBit(sic->rlive,IC_RESULT(dic)->key);
1572 remiCodeFromeBBlock(ebp,ic);
1573 hTabDeleteItem (&iCodehTab,ic->key,ic,DELETE_ITEM,NULL);
1574 OP_DEFS(IC_RESULT(dic)) = bitVectSetBit(OP_DEFS(IC_RESULT(dic)),dic->key);
1579 /*-----------------------------------------------------------------*/
1580 /* findAssignToSym : scanning backwards looks for first assig found*/
1581 /*-----------------------------------------------------------------*/
1582 static iCode *findAssignToSym (operand *op,iCode *ic)
1586 for (dic = ic->prev ; dic ; dic = dic->prev) {
1588 /* if definition by assignment */
1589 if (dic->op == '=' &&
1590 !POINTER_SET(dic) &&
1591 IC_RESULT(dic)->key == op->key
1592 /* && IS_TRUE_SYMOP(IC_RIGHT(dic)) */
1595 /* we are interested only if defined in far space */
1596 /* or in stack space in case of + & - */
1598 /* if assigned to a non-symbol then return
1600 if (!IS_SYMOP(IC_RIGHT(dic)))
1603 /* if the symbol is in far space then
1605 if (isOperandInFarSpace(IC_RIGHT(dic)))
1608 /* for + & - operations make sure that
1609 if it is on the stack it is the same
1610 as one of the three operands */
1611 if ((ic->op == '+' || ic->op == '-') &&
1612 OP_SYMBOL(IC_RIGHT(dic))->onStack) {
1614 if ( IC_RESULT(ic)->key != IC_RIGHT(dic)->key &&
1615 IC_LEFT(ic)->key != IC_RIGHT(dic)->key &&
1616 IC_RIGHT(ic)->key != IC_RIGHT(dic)->key)
1624 /* if we find an usage then we cannot delete it */
1625 if (IC_LEFT(dic) && IC_LEFT(dic)->key == op->key)
1628 if (IC_RIGHT(dic) && IC_RIGHT(dic)->key == op->key)
1631 if (POINTER_SET(dic) && IC_RESULT(dic)->key == op->key)
1635 /* now make sure that the right side of dic
1636 is not defined between ic & dic */
1638 iCode *sic = dic->next ;
1640 for (; sic != ic ; sic = sic->next)
1641 if (IC_RESULT(sic) &&
1642 IC_RESULT(sic)->key == IC_RIGHT(dic)->key)
1651 /*-----------------------------------------------------------------*/
1652 /* packRegsForSupport :- reduce some registers for support calls */
1653 /*-----------------------------------------------------------------*/
1654 static int packRegsForSupport (iCode *ic, eBBlock *ebp)
1657 /* for the left & right operand :- look to see if the
1658 left was assigned a true symbol in far space in that
1659 case replace them */
1660 if (IS_ITEMP(IC_LEFT(ic)) &&
1661 OP_SYMBOL(IC_LEFT(ic))->liveTo <= ic->seq) {
1662 iCode *dic = findAssignToSym(IC_LEFT(ic),ic);
1668 /* found it we need to remove it from the
1670 for ( sic = dic; sic != ic ; sic = sic->next )
1671 bitVectUnSetBit(sic->rlive,IC_LEFT(ic)->key);
1673 IC_LEFT(ic)->operand.symOperand =
1674 IC_RIGHT(dic)->operand.symOperand;
1675 IC_LEFT(ic)->key = IC_RIGHT(dic)->operand.symOperand->key;
1676 remiCodeFromeBBlock(ebp,dic);
1677 hTabDeleteItem (&iCodehTab,dic->key,dic,DELETE_ITEM,NULL);
1681 /* do the same for the right operand */
1684 IS_ITEMP(IC_RIGHT(ic)) &&
1685 OP_SYMBOL(IC_RIGHT(ic))->liveTo <= ic->seq) {
1686 iCode *dic = findAssignToSym(IC_RIGHT(ic),ic);
1692 /* if this is a subtraction & the result
1693 is a true symbol in far space then don't pack */
1694 if (ic->op == '-' && IS_TRUE_SYMOP(IC_RESULT(dic))) {
1695 sym_link *etype =getSpec(operandType(IC_RESULT(dic)));
1696 if (IN_FARSPACE(SPEC_OCLS(etype)))
1699 /* found it we need to remove it from the
1701 for ( sic = dic; sic != ic ; sic = sic->next )
1702 bitVectUnSetBit(sic->rlive,IC_RIGHT(ic)->key);
1704 IC_RIGHT(ic)->operand.symOperand =
1705 IC_RIGHT(dic)->operand.symOperand;
1706 IC_RIGHT(ic)->key = IC_RIGHT(dic)->operand.symOperand->key;
1708 remiCodeFromeBBlock(ebp,dic);
1709 hTabDeleteItem (&iCodehTab,dic->key,dic,DELETE_ITEM,NULL);
1716 #define IS_OP_RUONLY(x) (x && IS_SYMOP(x) && OP_SYMBOL(x)->ruonly)
1719 /*-----------------------------------------------------------------*/
1720 /* packRegsForOneuse : - will reduce some registers for single Use */
1721 /*-----------------------------------------------------------------*/
1722 static iCode *packRegsForOneuse (iCode *ic, operand *op , eBBlock *ebp)
1726 /* I can't figure out how to make this safe yet. */
1735 /* if returning a literal then do nothing */
1739 /* only upto 2 bytes since we cannot predict
1740 the usage of b, & acc */
1741 if (getSize(operandType(op)) > (fReturnSize_390 - 2) &&
1748 /* this routine will mark the a symbol as used in one
1749 instruction use only && if the defintion is local
1750 (ie. within the basic block) && has only one definition &&
1751 that definiion is either a return value from a
1752 function or does not contain any variables in
1754 uses = bitVectCopy(OP_USES(op));
1755 bitVectUnSetBit(uses,ic->key); /* take away this iCode */
1756 if (!bitVectIsZero(uses)) /* has other uses */
1759 /* if it has only one defintion */
1760 if (bitVectnBitsOn(OP_DEFS(op)) > 1)
1761 return NULL ; /* has more than one definition */
1763 /* get the that definition */
1765 hTabItemWithKey(iCodehTab,
1766 bitVectFirstBit(OP_DEFS(op)))))
1769 /* found the definition now check if it is local */
1770 if (dic->seq < ebp->fSeq ||
1771 dic->seq > ebp->lSeq)
1772 return NULL ; /* non-local */
1774 /* now check if it is the return from
1776 if (dic->op == CALL || dic->op == PCALL ) {
1777 if (ic->op != SEND && ic->op != RETURN) {
1778 OP_SYMBOL(op)->ruonly = 1;
1785 /* otherwise check that the definition does
1786 not contain any symbols in far space */
1787 if (isOperandInFarSpace(IC_LEFT(dic)) ||
1788 isOperandInFarSpace(IC_RIGHT(dic)) ||
1789 IS_OP_RUONLY(IC_LEFT(ic)) ||
1790 IS_OP_RUONLY(IC_RIGHT(ic)) ) {
1794 /* if pointer set then make sure the pointer
1796 if (POINTER_SET(dic) &&
1797 !IS_DATA_PTR(aggrToPtr(operandType(IC_RESULT(dic)),FALSE)))
1800 if (POINTER_GET(dic) &&
1801 !IS_DATA_PTR(aggrToPtr(operandType(IC_LEFT(dic)),FALSE)))
1806 /* also make sure the intervenening instructions
1807 don't have any thing in far space */
1808 for (dic = dic->next ; dic && dic != ic ; dic = dic->next) {
1810 /* if there is an intervening function call then no */
1811 if (dic->op == CALL || dic->op == PCALL)
1813 /* if pointer set then make sure the pointer
1815 if (POINTER_SET(dic) &&
1816 !IS_DATA_PTR(aggrToPtr(operandType(IC_RESULT(dic)),FALSE)))
1819 if (POINTER_GET(dic) &&
1820 !IS_DATA_PTR(aggrToPtr(operandType(IC_LEFT(dic)),FALSE)))
1823 /* if address of & the result is remat the okay */
1824 if (dic->op == ADDRESS_OF &&
1825 OP_SYMBOL(IC_RESULT(dic))->remat)
1828 /* if operand has size of three or more & this
1829 operation is a '*','/' or '%' then 'b' may
1831 if (( dic->op == '%' || dic->op == '/' || dic->op == '*') &&
1832 getSize(operandType(op)) >= 3)
1835 /* if left or right or result is in far space */
1836 if (isOperandInFarSpace(IC_LEFT(dic)) ||
1837 isOperandInFarSpace(IC_RIGHT(dic)) ||
1838 isOperandInFarSpace(IC_RESULT(dic)) ||
1839 IS_OP_RUONLY(IC_LEFT(dic)) ||
1840 IS_OP_RUONLY(IC_RIGHT(dic)) ||
1841 IS_OP_RUONLY(IC_RESULT(dic)) ) {
1846 OP_SYMBOL(op)->ruonly = 1;
1851 /*-----------------------------------------------------------------*/
1852 /* isBitwiseOptimizable - requirements of JEAN LOUIS VERN */
1853 /*-----------------------------------------------------------------*/
1854 static bool isBitwiseOptimizable (iCode *ic)
1856 sym_link *ltype = getSpec(operandType(IC_LEFT(ic)));
1857 sym_link *rtype = getSpec(operandType(IC_RIGHT(ic)));
1859 /* bitwise operations are considered optimizable
1860 under the following conditions (Jean-Louis VERN)
1872 if ( IS_LITERAL(rtype) ||
1873 (IS_BITVAR(ltype) && IN_BITSPACE(SPEC_OCLS(ltype))))
1879 /*-----------------------------------------------------------------*/
1880 /* packRegsForAccUse - pack registers for acc use */
1881 /*-----------------------------------------------------------------*/
1882 static void packRegsForAccUse (iCode *ic)
1886 /* if + or - then it has to be one byte result */
1887 if ((ic->op == '+' || ic->op == '-')
1888 && getSize(operandType(IC_RESULT(ic))) > 1)
1891 /* if shift operation make sure right side is not a literal */
1892 if (ic->op == RIGHT_OP &&
1893 ( isOperandLiteral(IC_RIGHT(ic)) ||
1894 getSize(operandType(IC_RESULT(ic))) > 1))
1897 if (ic->op == LEFT_OP &&
1898 ( isOperandLiteral(IC_RIGHT(ic)) ||
1899 getSize(operandType(IC_RESULT(ic))) > 1))
1902 if (IS_BITWISE_OP(ic) &&
1903 getSize(operandType(IC_RESULT(ic))) > 1)
1907 /* has only one definition */
1908 if (bitVectnBitsOn(OP_DEFS(IC_RESULT(ic))) > 1)
1911 /* has only one use */
1912 if (bitVectnBitsOn(OP_USES(IC_RESULT(ic))) > 1)
1915 /* and the usage immediately follows this iCode */
1916 if (!(uic = hTabItemWithKey(iCodehTab,
1917 bitVectFirstBit(OP_USES(IC_RESULT(ic))))))
1920 if (ic->next != uic)
1923 /* if it is a conditional branch then we definitely can */
1924 if (uic->op == IFX )
1927 if ( uic->op == JUMPTABLE )
1930 /* if the usage is not is an assignment
1931 or an arithmetic / bitwise / shift operation then not */
1932 if (POINTER_SET(uic) &&
1933 getSize(aggrToPtr(operandType(IC_RESULT(uic)),FALSE)) > 1)
1936 if (uic->op != '=' &&
1937 !IS_ARITHMETIC_OP(uic) &&
1938 !IS_BITWISE_OP(uic) &&
1939 uic->op != LEFT_OP &&
1940 uic->op != RIGHT_OP )
1943 /* if used in ^ operation then make sure right is not a
1945 if (uic->op == '^' && isOperandLiteral(IC_RIGHT(uic)))
1948 /* if shift operation make sure right side is not a literal */
1949 if (uic->op == RIGHT_OP &&
1950 ( isOperandLiteral(IC_RIGHT(uic)) ||
1951 getSize(operandType(IC_RESULT(uic))) > 1))
1954 if (uic->op == LEFT_OP &&
1955 ( isOperandLiteral(IC_RIGHT(uic)) ||
1956 getSize(operandType(IC_RESULT(uic))) > 1))
1959 /* make sure that the result of this icode is not on the
1960 stack, since acc is used to compute stack offset */
1961 if (IS_TRUE_SYMOP(IC_RESULT(uic)) &&
1962 OP_SYMBOL(IC_RESULT(uic))->onStack)
1965 /* if either one of them in far space then we cannot */
1966 if ((IS_TRUE_SYMOP(IC_LEFT(uic)) &&
1967 isOperandInFarSpace(IC_LEFT(uic))) ||
1968 (IS_TRUE_SYMOP(IC_RIGHT(uic)) &&
1969 isOperandInFarSpace(IC_RIGHT(uic))))
1972 /* if the usage has only one operand then we can */
1973 if (IC_LEFT(uic) == NULL ||
1974 IC_RIGHT(uic) == NULL)
1977 /* make sure this is on the left side if not
1978 a '+' since '+' is commutative */
1979 if (ic->op != '+' &&
1980 IC_LEFT(uic)->key != IC_RESULT(ic)->key)
1983 /* if one of them is a literal then we can */
1984 if ((IC_LEFT(uic) && IS_OP_LITERAL(IC_LEFT(uic))) ||
1985 (IC_RIGHT(uic) && IS_OP_LITERAL(IC_RIGHT(uic)))) {
1986 OP_SYMBOL(IC_RESULT(ic))->accuse = 1;
1990 /* if the other one is not on stack then we can */
1991 if (IC_LEFT(uic)->key == IC_RESULT(ic)->key &&
1992 (IS_ITEMP(IC_RIGHT(uic)) ||
1993 (IS_TRUE_SYMOP(IC_RIGHT(uic)) &&
1994 !OP_SYMBOL(IC_RIGHT(uic))->onStack)))
1997 if (IC_RIGHT(uic)->key == IC_RESULT(ic)->key &&
1998 (IS_ITEMP(IC_LEFT(uic)) ||
1999 (IS_TRUE_SYMOP(IC_LEFT(uic)) &&
2000 !OP_SYMBOL(IC_LEFT(uic))->onStack)))
2006 OP_SYMBOL(IC_RESULT(ic))->accuse = 1;
2011 /*-----------------------------------------------------------------*/
2012 /* packForPush - hueristics to reduce iCode for pushing */
2013 /*-----------------------------------------------------------------*/
2014 static void packForPush(iCode *ic, eBBlock *ebp)
2018 if (ic->op != IPUSH || !IS_ITEMP(IC_LEFT(ic)))
2021 /* must have only definition & one usage */
2022 if (bitVectnBitsOn(OP_DEFS(IC_LEFT(ic))) != 1 ||
2023 bitVectnBitsOn(OP_USES(IC_LEFT(ic))) != 1 )
2026 /* find the definition */
2027 if (!(dic = hTabItemWithKey(iCodehTab,
2028 bitVectFirstBit(OP_DEFS(IC_LEFT(ic))))))
2031 if (dic->op != '=' || POINTER_SET(dic))
2034 /* we now we know that it has one & only one def & use
2035 and the that the definition is an assignment */
2036 IC_LEFT(ic) = IC_RIGHT(dic);
2038 remiCodeFromeBBlock(ebp,dic);
2039 hTabDeleteItem (&iCodehTab,dic->key,dic,DELETE_ITEM,NULL);
2042 /*-----------------------------------------------------------------*/
2043 /* packRegisters - does some transformations to reduce register */
2045 /*-----------------------------------------------------------------*/
2046 static void packRegisters (eBBlock *ebp)
2055 /* look for assignments of the form */
2056 /* iTempNN = TRueSym (someoperation) SomeOperand */
2058 /* TrueSym := iTempNN:1 */
2059 for ( ic = ebp->sch ; ic ; ic = ic->next ) {
2062 /* find assignment of the form TrueSym := iTempNN:1 */
2063 if (ic->op == '=' && !POINTER_SET(ic))
2064 change += packRegsForAssign(ic,ebp);
2071 for ( ic = ebp->sch ; ic ; ic = ic->next ) {
2073 /* if this is an itemp & result of a address of a true sym
2074 then mark this as rematerialisable */
2075 if (ic->op == ADDRESS_OF &&
2076 IS_ITEMP(IC_RESULT(ic)) &&
2077 IS_TRUE_SYMOP(IC_LEFT(ic)) &&
2078 bitVectnBitsOn(OP_DEFS(IC_RESULT(ic))) == 1 &&
2079 !OP_SYMBOL(IC_LEFT(ic))->onStack ) {
2081 OP_SYMBOL(IC_RESULT(ic))->remat = 1;
2082 OP_SYMBOL(IC_RESULT(ic))->rematiCode = ic;
2083 OP_SYMBOL(IC_RESULT(ic))->usl.spillLoc = NULL;
2087 /* if straight assignment then carry remat flag if
2088 this is the only definition */
2089 if (ic->op == '=' &&
2091 IS_SYMOP(IC_RIGHT(ic)) &&
2092 OP_SYMBOL(IC_RIGHT(ic))->remat &&
2093 bitVectnBitsOn(OP_SYMBOL(IC_RESULT(ic))->defs) <= 1) {
2095 OP_SYMBOL(IC_RESULT(ic))->remat =
2096 OP_SYMBOL(IC_RIGHT(ic))->remat;
2097 OP_SYMBOL(IC_RESULT(ic))->rematiCode =
2098 OP_SYMBOL(IC_RIGHT(ic))->rematiCode ;
2101 /* if this is a +/- operation with a rematerizable
2102 then mark this as rematerializable as well */
2103 if ((ic->op == '+' || ic->op == '-') &&
2104 (IS_SYMOP(IC_LEFT(ic)) &&
2105 IS_ITEMP(IC_RESULT(ic)) &&
2106 OP_SYMBOL(IC_LEFT(ic))->remat &&
2107 bitVectnBitsOn(OP_DEFS(IC_RESULT(ic))) == 1 &&
2108 IS_OP_LITERAL(IC_RIGHT(ic))) ) {
2110 //int i = operandLitValue(IC_RIGHT(ic));
2111 OP_SYMBOL(IC_RESULT(ic))->remat = 1;
2112 OP_SYMBOL(IC_RESULT(ic))->rematiCode = ic;
2113 OP_SYMBOL(IC_RESULT(ic))->usl.spillLoc = NULL;
2116 /* mark the pointer usages */
2117 if (POINTER_SET(ic))
2118 OP_SYMBOL(IC_RESULT(ic))->uptr = 1;
2120 if (POINTER_GET(ic))
2121 OP_SYMBOL(IC_LEFT(ic))->uptr = 1;
2123 if (!SKIP_IC2(ic)) {
2124 /* if we are using a symbol on the stack
2125 then we should say ds390_ptrRegReq */
2126 if (ic->op == IFX && IS_SYMOP(IC_COND(ic)))
2127 ds390_ptrRegReq += ((OP_SYMBOL(IC_COND(ic))->onStack ||
2128 OP_SYMBOL(IC_COND(ic))->iaccess) ? 1 : 0);
2130 if (ic->op == JUMPTABLE && IS_SYMOP(IC_JTCOND(ic)))
2131 ds390_ptrRegReq += ((OP_SYMBOL(IC_JTCOND(ic))->onStack ||
2132 OP_SYMBOL(IC_JTCOND(ic))->iaccess) ? 1 : 0);
2134 if (IS_SYMOP(IC_LEFT(ic)))
2135 ds390_ptrRegReq += ((OP_SYMBOL(IC_LEFT(ic))->onStack ||
2136 OP_SYMBOL(IC_LEFT(ic))->iaccess) ? 1 : 0);
2137 if (IS_SYMOP(IC_RIGHT(ic)))
2138 ds390_ptrRegReq += ((OP_SYMBOL(IC_RIGHT(ic))->onStack ||
2139 OP_SYMBOL(IC_RIGHT(ic))->iaccess) ? 1 : 0);
2140 if (IS_SYMOP(IC_RESULT(ic)))
2141 ds390_ptrRegReq += ((OP_SYMBOL(IC_RESULT(ic))->onStack ||
2142 OP_SYMBOL(IC_RESULT(ic))->iaccess) ? 1 : 0);
2146 /* if the condition of an if instruction
2147 is defined in the previous instruction then
2148 mark the itemp as a conditional */
2149 if ((IS_CONDITIONAL(ic) ||
2150 ( ( ic->op == BITWISEAND ||
2153 isBitwiseOptimizable(ic))) &&
2154 ic->next && ic->next->op == IFX &&
2155 isOperandEqual(IC_RESULT(ic),IC_COND(ic->next)) &&
2156 OP_SYMBOL(IC_RESULT(ic))->liveTo <= ic->next->seq) {
2158 OP_SYMBOL(IC_RESULT(ic))->regType = REG_CND;
2162 /* reduce for support function calls */
2163 if (ic->supportRtn || ic->op == '+' || ic->op == '-' )
2164 packRegsForSupport (ic,ebp);
2166 /* some cases the redundant moves can
2167 can be eliminated for return statements */
2168 if ((ic->op == RETURN || ic->op == SEND) &&
2169 !isOperandInFarSpace(IC_LEFT(ic)) &&
2171 packRegsForOneuse (ic,IC_LEFT(ic),ebp);
2173 /* if pointer set & left has a size more than
2174 one and right is not in far space */
2175 if (POINTER_SET(ic) &&
2176 !isOperandInFarSpace(IC_RIGHT(ic)) &&
2177 !OP_SYMBOL(IC_RESULT(ic))->remat &&
2178 !IS_OP_RUONLY(IC_RIGHT(ic)) &&
2179 getSize(aggrToPtr(operandType(IC_RESULT(ic)),FALSE)) > 1 )
2181 packRegsForOneuse (ic,IC_RESULT(ic),ebp);
2183 /* if pointer get */
2184 if (POINTER_GET(ic) &&
2185 !isOperandInFarSpace(IC_RESULT(ic))&&
2186 !OP_SYMBOL(IC_LEFT(ic))->remat &&
2187 !IS_OP_RUONLY(IC_RESULT(ic)) &&
2188 getSize(aggrToPtr(operandType(IC_LEFT(ic)),FALSE)) > 1 )
2190 packRegsForOneuse (ic,IC_LEFT(ic),ebp);
2193 /* if this is cast for intergral promotion then
2194 check if only use of the definition of the
2195 operand being casted/ if yes then replace
2196 the result of that arithmetic operation with
2197 this result and get rid of the cast */
2198 if (ic->op == CAST) {
2199 sym_link *fromType = operandType(IC_RIGHT(ic));
2200 sym_link *toType = operandType(IC_LEFT(ic));
2202 if (IS_INTEGRAL(fromType) && IS_INTEGRAL(toType) &&
2203 getSize(fromType) != getSize(toType) &&
2204 SPEC_USIGN(fromType) == SPEC_USIGN(toType)) {
2206 iCode *dic = packRegsForOneuse(ic,IC_RIGHT(ic),ebp);
2208 if (IS_ARITHMETIC_OP(dic)) {
2209 IC_RESULT(dic) = IC_RESULT(ic);
2210 remiCodeFromeBBlock(ebp,ic);
2211 hTabDeleteItem (&iCodehTab,ic->key,ic,DELETE_ITEM,NULL);
2212 OP_DEFS(IC_RESULT(dic)) = bitVectSetBit(OP_DEFS(IC_RESULT(dic)),dic->key);
2215 OP_SYMBOL(IC_RIGHT(ic))->ruonly = 0;
2219 /* if the type from and type to are the same
2220 then if this is the only use then packit */
2221 if (checkType(operandType(IC_RIGHT(ic)),
2222 operandType(IC_LEFT(ic))) == 1) {
2223 iCode *dic = packRegsForOneuse (ic,IC_RIGHT(ic),ebp);
2225 IC_RESULT(dic) = IC_RESULT(ic);
2226 remiCodeFromeBBlock(ebp,ic);
2227 hTabDeleteItem (&iCodehTab,ic->key,ic,DELETE_ITEM,NULL);
2228 OP_DEFS(IC_RESULT(dic)) = bitVectSetBit(OP_DEFS(IC_RESULT(dic)),dic->key);
2236 iTempNN := (some variable in farspace) V1
2241 if (ic->op == IPUSH ) {
2242 packForPush(ic,ebp);
2246 /* pack registers for accumulator use, when the
2247 result of an arithmetic or bit wise operation
2248 has only one use, that use is immediately following
2249 the defintion and the using iCode has only one
2250 operand or has two operands but one is literal &
2251 the result of that operation is not on stack then
2252 we can leave the result of this operation in acc:b
2254 if ((IS_ARITHMETIC_OP(ic)
2256 || IS_BITWISE_OP(ic)
2258 || ic->op == LEFT_OP || ic->op == RIGHT_OP
2261 IS_ITEMP(IC_RESULT(ic)) &&
2262 getSize(operandType(IC_RESULT(ic))) <= 2)
2264 packRegsForAccUse (ic);
2269 /*-----------------------------------------------------------------*/
2270 /* assignRegisters - assigns registers to each live range as need */
2271 /*-----------------------------------------------------------------*/
2272 void ds390_assignRegisters (eBBlock **ebbs, int count)
2277 setToNull((void *)&_G.funcrUsed);
2278 ds390_ptrRegReq = _G.stackExtend = _G.dataExtend = 0;
2279 /* if not register extentions then reduce number
2281 if (options.regExtend)
2286 /* change assignments this will remove some
2287 live ranges reducing some register pressure */
2288 for (i = 0 ; i < count ;i++ )
2289 packRegisters (ebbs[i]);
2291 if (options.dump_pack)
2292 dumpEbbsToFileExt(".dumppack",ebbs,count);
2294 /* first determine for each live range the number of
2295 registers & the type of registers required for each */
2298 /* and serially allocate registers */
2299 serialRegAssign(ebbs,count);
2301 /* if stack was extended then tell the user */
2302 if (_G.stackExtend) {
2303 /* werror(W_TOOMANY_SPILS,"stack", */
2304 /* _G.stackExtend,currFunc->name,""); */
2305 _G.stackExtend = 0 ;
2308 if (_G.dataExtend) {
2309 /* werror(W_TOOMANY_SPILS,"data space", */
2310 /* _G.dataExtend,currFunc->name,""); */
2314 /* after that create the register mask
2315 for each of the instruction */
2316 createRegMask (ebbs,count);
2318 /* redo that offsets for stacked automatic variables */
2319 redoStackOffsets ();
2321 if (options.dump_rassgn)
2322 dumpEbbsToFileExt(".dumprassgn",ebbs,count);
2324 /* do the overlaysegment stuff SDCCmem.c */
2325 doOverlays(ebbs,count);
2327 /* now get back the chain */
2328 ic = iCodeLabelOptimize(iCodeFromeBBlock (ebbs,count));
2333 /* free up any _G.stackSpil locations allocated */
2334 applyToSet(_G.stackSpil,deallocStackSpil);
2336 setToNull((void **)&_G.stackSpil);
2337 setToNull((void **)&_G.spiltSet);
2338 /* mark all registers as free */