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 /*-----------------------------------------------------------------*/
39 extern void gen390Code(iCode *);
48 bitVect *funcrUsed; /* registers used in a function */
53 /* Shared with gen.c */
54 int ds390_ptrRegReq; /* one byte pointer register required */
60 { REG_GPR ,R2_IDX , REG_GPR , "r2", "ar2", "0", 2, 1 },
61 { REG_GPR ,R3_IDX , REG_GPR , "r3", "ar3", "0", 3, 1 },
62 { REG_GPR ,R4_IDX , REG_GPR , "r4", "ar4", "0", 4, 1 },
63 { REG_GPR ,R5_IDX , REG_GPR , "r5", "ar5", "0", 5, 1 },
64 { REG_GPR ,R6_IDX , REG_GPR , "r6", "ar6", "0", 6, 1 },
65 { REG_GPR ,R7_IDX , REG_GPR , "r7", "ar7", "0", 7, 1 },
66 { REG_PTR ,R0_IDX , REG_PTR , "r0" , "ar0", "0", 0, 1 },
67 { REG_PTR ,R1_IDX , REG_PTR , "r1" , "ar1", "0", 1, 1 },
68 { REG_GPR ,X8_IDX , REG_GPR , "x8", "x8" , "xreg", 0, 1 },
69 { REG_GPR ,X9_IDX , REG_GPR , "x9", "x9" , "xreg", 1, 1 },
70 { REG_GPR ,X10_IDX,REG_GPR , "x10", "x10", "xreg", 2, 1 },
71 { REG_GPR ,X11_IDX,REG_GPR , "x11", "x11", "xreg", 3, 1 },
72 { REG_GPR ,X12_IDX,REG_GPR , "x12", "x12", "xreg", 4, 1 },
73 { REG_CND ,CND_IDX,REG_CND , "C" , "C" , "xreg", 0, 1 },
76 static void spillThis (symbol *);
78 /*-----------------------------------------------------------------*/
79 /* allocReg - allocates register of given type */
80 /*-----------------------------------------------------------------*/
81 static regs *allocReg (short type)
85 for ( i = 0 ; i < ds390_nRegs ; i++ ) {
87 /* if type is given as 0 then any
88 free register will do */
91 regs390[i].isFree = 0;
94 bitVectSetBit(currFunc->regsUsed,i);
97 /* other wise look for specific type
99 if (regs390[i].isFree &&
100 regs390[i].type == type) {
101 regs390[i].isFree = 0;
104 bitVectSetBit(currFunc->regsUsed,i);
111 /*-----------------------------------------------------------------*/
112 /* ds390_regWithIdx - returns pointer to register wit index number */
113 /*-----------------------------------------------------------------*/
114 regs *ds390_regWithIdx (int idx)
118 for (i=0;i < ds390_nRegs;i++)
119 if (regs390[i].rIdx == idx)
122 werror(E_INTERNAL_ERROR,__FILE__,__LINE__,
123 "regWithIdx not found");
127 /*-----------------------------------------------------------------*/
128 /* freeReg - frees a register */
129 /*-----------------------------------------------------------------*/
130 static void freeReg (regs *reg)
136 /*-----------------------------------------------------------------*/
137 /* nFreeRegs - returns number of free registers */
138 /*-----------------------------------------------------------------*/
139 static int nFreeRegs (int type)
144 for (i = 0 ; i < ds390_nRegs; i++ )
145 if (regs390[i].isFree && regs390[i].type == type)
150 /*-----------------------------------------------------------------*/
151 /* nfreeRegsType - free registers with type */
152 /*-----------------------------------------------------------------*/
153 static int nfreeRegsType (int type)
156 if (type == REG_PTR) {
157 if ((nfr = nFreeRegs(type)) == 0)
158 return nFreeRegs(REG_GPR);
161 return nFreeRegs(type);
165 /*-----------------------------------------------------------------*/
166 /* allDefsOutOfRange - all definitions are out of a range */
167 /*-----------------------------------------------------------------*/
168 static bool allDefsOutOfRange (bitVect *defs,int fseq, int toseq)
175 for ( i = 0 ;i < defs->size ; i++ ) {
178 if (bitVectBitValue(defs,i) &&
179 (ic = hTabItemWithKey(iCodehTab,i)) &&
180 ( ic->seq >= fseq && ic->seq <= toseq))
189 /*-----------------------------------------------------------------*/
190 /* computeSpillable - given a point find the spillable live ranges */
191 /*-----------------------------------------------------------------*/
192 static bitVect *computeSpillable (iCode *ic)
196 /* spillable live ranges are those that are live at this
197 point . the following categories need to be subtracted
199 a) - those that are already spilt
200 b) - if being used by this one
201 c) - defined by this one */
203 spillable = bitVectCopy(ic->rlive);
205 bitVectCplAnd(spillable,_G.spiltSet); /* those already spilt */
207 bitVectCplAnd(spillable,ic->uses); /* used in this one */
208 bitVectUnSetBit(spillable,ic->defKey);
209 spillable = bitVectIntersect(spillable,_G.regAssigned);
214 /*-----------------------------------------------------------------*/
215 /* noSpilLoc - return true if a variable has no spil location */
216 /*-----------------------------------------------------------------*/
217 static int noSpilLoc (symbol *sym, eBBlock *ebp,iCode *ic)
219 return (sym->usl.spillLoc ? 0 : 1);
222 /*-----------------------------------------------------------------*/
223 /* hasSpilLoc - will return 1 if the symbol has spil location */
224 /*-----------------------------------------------------------------*/
225 static int hasSpilLoc (symbol *sym, eBBlock *ebp, iCode *ic)
227 return (sym->usl.spillLoc ? 1 : 0);
230 /*-----------------------------------------------------------------*/
231 /* directSpilLoc - will return 1 if the splilocation is in direct */
232 /*-----------------------------------------------------------------*/
233 static int directSpilLoc (symbol *sym, eBBlock *ebp, iCode *ic)
235 if ( sym->usl.spillLoc &&
236 (IN_DIRSPACE(SPEC_OCLS(sym->usl.spillLoc->etype))))
242 /*-----------------------------------------------------------------*/
243 /* hasSpilLocnoUptr - will return 1 if the symbol has spil location*/
244 /* but is not used as a pointer */
245 /*-----------------------------------------------------------------*/
246 static int hasSpilLocnoUptr (symbol *sym, eBBlock *ebp, iCode *ic)
248 return ((sym->usl.spillLoc && !sym->uptr) ? 1 : 0);
251 /*-----------------------------------------------------------------*/
252 /* rematable - will return 1 if the remat flag is set */
253 /*-----------------------------------------------------------------*/
254 static int rematable (symbol *sym, eBBlock *ebp, iCode *ic)
259 /*-----------------------------------------------------------------*/
260 /* notUsedInBlock - not used in this block */
261 /*-----------------------------------------------------------------*/
262 static int notUsedInBlock (symbol *sym, eBBlock *ebp, iCode *ic)
264 return (!bitVectBitsInCommon(sym->defs,ebp->usesDefs) &&
265 allDefsOutOfRange (sym->defs,ebp->fSeq,ebp->lSeq));
266 /* return (!bitVectBitsInCommon(sym->defs,ebp->usesDefs)); */
269 /*-----------------------------------------------------------------*/
270 /* notUsedInRemaining - not used or defined in remain of the block */
271 /*-----------------------------------------------------------------*/
272 static int notUsedInRemaining (symbol *sym, eBBlock *ebp, iCode *ic)
274 return ((usedInRemaining (operandFromSymbol(sym),ic) ? 0 : 1) &&
275 allDefsOutOfRange (sym->defs,ebp->fSeq,ebp->lSeq));
278 /*-----------------------------------------------------------------*/
279 /* allLRs - return true for all */
280 /*-----------------------------------------------------------------*/
281 static int allLRs (symbol *sym, eBBlock *ebp, iCode *ic)
286 /*-----------------------------------------------------------------*/
287 /* liveRangesWith - applies function to a given set of live range */
288 /*-----------------------------------------------------------------*/
289 static set *liveRangesWith (bitVect *lrs, int (func)(symbol *,eBBlock *, iCode *),
290 eBBlock *ebp, iCode *ic)
295 if (!lrs || !lrs->size)
298 for ( i = 1 ; i < lrs->size ; i++ ) {
300 if (!bitVectBitValue(lrs,i))
303 /* if we don't find it in the live range
304 hash table we are in serious trouble */
305 if (!(sym = hTabItemWithKey(liveRanges,i))) {
306 werror(E_INTERNAL_ERROR,__FILE__,__LINE__,
307 "liveRangesWith could not find liveRange");
311 if (func(sym,ebp,ic) && bitVectBitValue(_G.regAssigned,sym->key))
312 addSetHead(&rset,sym);
319 /*-----------------------------------------------------------------*/
320 /* leastUsedLR - given a set determines which is the least used */
321 /*-----------------------------------------------------------------*/
322 static symbol *leastUsedLR (set *sset)
324 symbol *sym = NULL, *lsym = NULL ;
326 sym = lsym = setFirstItem(sset);
331 for (; lsym; lsym = setNextItem(sset)) {
333 /* if usage is the same then prefer
334 the spill the smaller of the two */
335 if ( lsym->used == sym->used )
336 if (getSize(lsym->type) < getSize(sym->type))
340 if (lsym->used < sym->used )
345 setToNull((void **)&sset);
350 /*-----------------------------------------------------------------*/
351 /* noOverLap - will iterate through the list looking for over lap */
352 /*-----------------------------------------------------------------*/
353 static int noOverLap (set *itmpStack, symbol *fsym)
358 for (sym = setFirstItem(itmpStack); sym;
359 sym = setNextItem(itmpStack)) {
360 if (sym->liveTo > fsym->liveFrom )
368 /*-----------------------------------------------------------------*/
369 /* isFree - will return 1 if the a free spil location is found */
370 /*-----------------------------------------------------------------*/
371 static DEFSETFUNC(isFree)
374 V_ARG(symbol **,sloc);
375 V_ARG(symbol *,fsym);
377 /* if already found */
381 /* if it is free && and the itmp assigned to
382 this does not have any overlapping live ranges
383 with the one currently being assigned and
384 the size can be accomodated */
386 noOverLap(sym->usl.itmpStack,fsym) &&
387 getSize(sym->type) >= getSize(fsym->type)) {
395 /*-----------------------------------------------------------------*/
396 /* spillLRWithPtrReg :- will spil those live ranges which use PTR */
397 /*-----------------------------------------------------------------*/
398 static void spillLRWithPtrReg (symbol *forSym)
404 if (!_G.regAssigned ||
405 bitVectIsZero(_G.regAssigned))
408 r0 = ds390_regWithIdx(R0_IDX);
409 r1 = ds390_regWithIdx(R1_IDX);
411 /* for all live ranges */
412 for (lrsym = hTabFirstItem(liveRanges,&k) ; lrsym ;
413 lrsym = hTabNextItem(liveRanges,&k) ) {
416 /* if no registers assigned to it or
418 /* if it does not overlap with this then
419 not need to spill it */
421 if (lrsym->isspilt || !lrsym->nRegs ||
422 (lrsym->liveTo < forSym->liveFrom))
425 /* go thru the registers : if it is either
426 r0 or r1 then spil it */
427 for (j = 0 ; j < lrsym->nRegs ; j++ )
428 if (lrsym->regs[j] == r0 ||
429 lrsym->regs[j] == r1 ) {
437 /*-----------------------------------------------------------------*/
438 /* createStackSpil - create a location on the stack to spil */
439 /*-----------------------------------------------------------------*/
440 static symbol *createStackSpil (symbol *sym)
443 int useXstack, model, noOverlay;
447 /* first go try and find a free one that is already
448 existing on the stack */
449 if (applyToSet(_G.stackSpil,isFree,&sloc, sym)) {
450 /* found a free one : just update & return */
451 sym->usl.spillLoc = sloc;
454 addSetHead(&sloc->usl.itmpStack,sym);
458 /* could not then have to create one , this is the hard part
459 we need to allocate this on the stack : this is really a
460 hack!! but cannot think of anything better at this time */
462 if (sprintf(slocBuffer,"sloc%d",_G.slocNum++) >= sizeof(slocBuffer))
464 fprintf(stderr, "***Internal error: slocBuffer overflowed: %s:%d\n",
469 sloc = newiTemp(slocBuffer);
471 /* set the type to the spilling symbol */
472 sloc->type = copyLinkChain(sym->type);
473 sloc->etype = getSpec(sloc->type);
474 SPEC_SCLS(sloc->etype) = options.model ? S_XDATA : S_DATA;
475 SPEC_EXTR(sloc->etype) = 0;
477 /* we don't allow it to be allocated`
478 onto the external stack since : so we
479 temporarily turn it off ; we also
480 turn off memory model to prevent
481 the spil from going to the external storage
482 and turn off overlaying
485 useXstack = options.useXstack;
486 model = options.model;
487 noOverlay = options.noOverlay;
488 options.noOverlay = 1;
490 /* options.model = options.useXstack = 0; */
494 options.useXstack = useXstack;
495 options.model = model;
496 options.noOverlay = noOverlay;
497 sloc->isref = 1; /* to prevent compiler warning */
499 /* if it is on the stack then update the stack */
500 if (IN_STACK(sloc->etype)) {
501 currFunc->stack += getSize(sloc->type);
502 _G.stackExtend += getSize(sloc->type);
504 _G.dataExtend += getSize(sloc->type);
506 /* add it to the _G.stackSpil set */
507 addSetHead(&_G.stackSpil,sloc);
508 sym->usl.spillLoc = sloc;
511 /* add it to the set of itempStack set
512 of the spill location */
513 addSetHead(&sloc->usl.itmpStack,sym);
517 /*-----------------------------------------------------------------*/
518 /* isSpiltOnStack - returns true if the spil location is on stack */
519 /*-----------------------------------------------------------------*/
520 static bool isSpiltOnStack (symbol *sym)
530 /* if (sym->_G.stackSpil) */
533 if (!sym->usl.spillLoc)
536 etype = getSpec(sym->usl.spillLoc->type);
543 /*-----------------------------------------------------------------*/
544 /* spillThis - spils a specific operand */
545 /*-----------------------------------------------------------------*/
546 static void spillThis (symbol *sym)
549 /* if this is rematerializable or has a spillLocation
550 we are okay, else we need to create a spillLocation
552 if (!(sym->remat || sym->usl.spillLoc))
553 createStackSpil (sym);
556 /* mark it has spilt & put it in the spilt set */
558 _G.spiltSet = bitVectSetBit(_G.spiltSet,sym->key);
560 bitVectUnSetBit(_G.regAssigned,sym->key);
562 for (i = 0 ; i < sym->nRegs ; i++)
565 freeReg(sym->regs[i]);
569 /* if spilt on stack then free up r0 & r1
570 if they could have been assigned to some
572 if (!ds390_ptrRegReq && isSpiltOnStack(sym)) {
574 spillLRWithPtrReg(sym);
577 if (sym->usl.spillLoc && !sym->remat)
578 sym->usl.spillLoc->allocreq = 1;
582 /*-----------------------------------------------------------------*/
583 /* selectSpil - select a iTemp to spil : rather a simple procedure */
584 /*-----------------------------------------------------------------*/
585 static symbol *selectSpil (iCode *ic, eBBlock *ebp, symbol *forSym)
587 bitVect *lrcs= NULL ;
591 /* get the spillable live ranges */
592 lrcs = computeSpillable (ic);
594 /* get all live ranges that are rematerizable */
595 if ((selectS = liveRangesWith(lrcs,rematable,ebp,ic))) {
597 /* return the least used of these */
598 return leastUsedLR(selectS);
601 /* get live ranges with spillLocations in direct space */
602 if ((selectS = liveRangesWith(lrcs,directSpilLoc,ebp,ic))) {
603 sym = leastUsedLR(selectS);
604 strcpy(sym->rname,(sym->usl.spillLoc->rname[0] ?
605 sym->usl.spillLoc->rname :
606 sym->usl.spillLoc->name));
608 /* mark it as allocation required */
609 sym->usl.spillLoc->allocreq = 1;
613 /* if the symbol is local to the block then */
614 if (forSym->liveTo < ebp->lSeq) {
616 /* check if there are any live ranges allocated
617 to registers that are not used in this block */
618 if (!_G.blockSpil && (selectS = liveRangesWith(lrcs,notUsedInBlock,ebp,ic))) {
619 sym = leastUsedLR(selectS);
620 /* if this is not rematerializable */
628 /* check if there are any live ranges that not
629 used in the remainder of the block */
630 if (!_G.blockSpil && (selectS = liveRangesWith(lrcs,notUsedInRemaining,ebp,ic))) {
631 sym = leastUsedLR (selectS);
642 /* find live ranges with spillocation && not used as pointers */
643 if ((selectS = liveRangesWith(lrcs,hasSpilLocnoUptr,ebp,ic))) {
645 sym = leastUsedLR(selectS);
646 /* mark this as allocation required */
647 sym->usl.spillLoc->allocreq = 1;
651 /* find live ranges with spillocation */
652 if ((selectS = liveRangesWith(lrcs,hasSpilLoc,ebp,ic))) {
654 sym = leastUsedLR(selectS);
655 sym->usl.spillLoc->allocreq = 1;
659 /* couldn't find then we need to create a spil
660 location on the stack , for which one? the least
662 if ((selectS = liveRangesWith(lrcs,noSpilLoc,ebp,ic))) {
664 /* return a created spil location */
665 sym = createStackSpil(leastUsedLR(selectS));
666 sym->usl.spillLoc->allocreq = 1;
670 /* this is an extreme situation we will spill
671 this one : happens very rarely but it does happen */
672 spillThis ( forSym );
677 /*-----------------------------------------------------------------*/
678 /* spilSomething - spil some variable & mark registers as free */
679 /*-----------------------------------------------------------------*/
680 static bool spilSomething (iCode *ic, eBBlock *ebp, symbol *forSym)
685 /* get something we can spil */
686 ssym = selectSpil(ic,ebp,forSym);
688 /* mark it as spilt */
690 _G.spiltSet = bitVectSetBit(_G.spiltSet,ssym->key);
692 /* mark it as not register assigned &
693 take it away from the set */
694 bitVectUnSetBit(_G.regAssigned,ssym->key);
696 /* mark the registers as free */
697 for (i = 0 ; i < ssym->nRegs ;i++ )
699 freeReg(ssym->regs[i]);
701 /* if spilt on stack then free up r0 & r1
702 if they could have been assigned to as gprs */
703 if (!ds390_ptrRegReq && isSpiltOnStack(ssym) ) {
705 spillLRWithPtrReg(ssym);
708 /* if this was a block level spil then insert push & pop
709 at the start & end of block respectively */
710 if (ssym->blockSpil) {
711 iCode *nic = newiCode(IPUSH,operandFromSymbol(ssym),NULL);
712 /* add push to the start of the block */
713 addiCodeToeBBlock(ebp,nic,( ebp->sch->op == LABEL ?
714 ebp->sch->next : ebp->sch));
715 nic = newiCode(IPOP,operandFromSymbol(ssym),NULL);
716 /* add pop to the end of the block */
717 addiCodeToeBBlock(ebp,nic,NULL);
720 /* if spilt because not used in the remainder of the
721 block then add a push before this instruction and
722 a pop at the end of the block */
723 if (ssym->remainSpil) {
725 iCode *nic = newiCode(IPUSH,operandFromSymbol(ssym),NULL);
726 /* add push just before this instruction */
727 addiCodeToeBBlock(ebp,nic,ic);
729 nic = newiCode(IPOP,operandFromSymbol(ssym),NULL);
730 /* add pop to the end of the block */
731 addiCodeToeBBlock(ebp,nic,NULL);
740 /*-----------------------------------------------------------------*/
741 /* getRegPtr - will try for PTR if not a GPR type if not spil */
742 /*-----------------------------------------------------------------*/
743 static regs *getRegPtr (iCode *ic, eBBlock *ebp, symbol *sym)
748 /* try for a ptr type */
749 if ((reg = allocReg(REG_PTR)))
752 /* try for gpr type */
753 if ((reg = allocReg(REG_GPR)))
756 /* we have to spil */
757 if (!spilSomething (ic,ebp,sym))
760 /* this looks like an infinite loop but
761 in really selectSpil will abort */
765 /*-----------------------------------------------------------------*/
766 /* getRegGpr - will try for GPR if not spil */
767 /*-----------------------------------------------------------------*/
768 static regs *getRegGpr (iCode *ic, eBBlock *ebp,symbol *sym)
773 /* try for gpr type */
774 if ((reg = allocReg(REG_GPR)))
777 if (!ds390_ptrRegReq)
778 if ((reg = allocReg(REG_PTR)))
781 /* we have to spil */
782 if (!spilSomething (ic,ebp,sym))
785 /* this looks like an infinite loop but
786 in really selectSpil will abort */
790 /*-----------------------------------------------------------------*/
791 /* symHasReg - symbol has a given register */
792 /*-----------------------------------------------------------------*/
793 static bool symHasReg(symbol *sym,regs *reg)
797 for ( i = 0 ; i < sym->nRegs ; i++)
798 if (sym->regs[i] == reg)
804 /*-----------------------------------------------------------------*/
805 /* deassignLRs - check the live to and if they have registers & are*/
806 /* not spilt then free up the registers */
807 /*-----------------------------------------------------------------*/
808 static void deassignLRs (iCode *ic, eBBlock *ebp)
814 for (sym = hTabFirstItem(liveRanges,&k); sym;
815 sym = hTabNextItem(liveRanges,&k)) {
818 /* if it does not end here */
819 if (sym->liveTo > ic->seq )
822 /* if it was spilt on stack then we can
823 mark the stack spil location as free */
825 if (sym->stackSpil) {
826 sym->usl.spillLoc->isFree = 1;
832 if (!bitVectBitValue(_G.regAssigned,sym->key))
835 /* special case check if this is an IFX &
836 the privious one was a pop and the
837 previous one was not spilt then keep track
839 if (ic->op == IFX && ic->prev &&
840 ic->prev->op == IPOP &&
841 !ic->prev->parmPush &&
842 !OP_SYMBOL(IC_LEFT(ic->prev))->isspilt)
843 psym = OP_SYMBOL(IC_LEFT(ic->prev));
848 bitVectUnSetBit(_G.regAssigned,sym->key);
850 /* if the result of this one needs registers
851 and does not have it then assign it right
854 ! (SKIP_IC2(ic) || /* not a special icode */
855 ic->op == JUMPTABLE ||
861 (result = OP_SYMBOL(IC_RESULT(ic))) && /* has a result */
862 result->liveTo > ic->seq && /* and will live beyond this */
863 result->liveTo <= ebp->lSeq && /* does not go beyond this block */
864 result->regType == sym->regType && /* same register types */
865 result->nRegs && /* which needs registers */
866 ! result->isspilt && /* and does not already have them */
868 ! bitVectBitValue(_G.regAssigned,result->key) &&
869 /* the number of free regs + number of regs in this LR
870 can accomodate the what result Needs */
871 ((nfreeRegsType(result->regType) +
872 sym->nRegs) >= result->nRegs)
875 for (i = 0 ; i < result->nRegs ; i++)
877 result->regs[i] = sym->regs[i] ;
879 result->regs[i] = getRegGpr (ic,ebp,result);
881 _G.regAssigned = bitVectSetBit(_G.regAssigned,result->key);
885 /* free the remaining */
886 for (; i < sym->nRegs ; i++) {
888 if (!symHasReg(psym,sym->regs[i]))
889 freeReg(sym->regs[i]);
891 freeReg(sym->regs[i]);
898 /*-----------------------------------------------------------------*/
899 /* reassignLR - reassign this to registers */
900 /*-----------------------------------------------------------------*/
901 static void reassignLR (operand *op)
903 symbol *sym = OP_SYMBOL(op);
906 /* not spilt any more */
907 sym->isspilt = sym->blockSpil = sym->remainSpil = 0;
908 bitVectUnSetBit(_G.spiltSet,sym->key);
910 _G.regAssigned = bitVectSetBit(_G.regAssigned,sym->key);
914 for (i=0;i<sym->nRegs;i++)
915 sym->regs[i]->isFree = 0;
918 /*-----------------------------------------------------------------*/
919 /* willCauseSpill - determines if allocating will cause a spill */
920 /*-----------------------------------------------------------------*/
921 static int willCauseSpill ( int nr, int rt)
923 /* first check if there are any avlb registers
924 of te type required */
926 /* special case for pointer type
927 if pointer type not avlb then
928 check for type gpr */
929 if (nFreeRegs(rt) >= nr)
931 if (nFreeRegs(REG_GPR) >= nr)
934 if (ds390_ptrRegReq) {
935 if (nFreeRegs(rt) >= nr)
938 if (nFreeRegs(REG_PTR) +
939 nFreeRegs(REG_GPR) >= nr)
944 /* it will cause a spil */
948 /*-----------------------------------------------------------------*/
949 /* positionRegs - the allocator can allocate same registers to res-*/
950 /* ult and operand, if this happens make sure they are in the same */
951 /* position as the operand otherwise chaos results */
952 /*-----------------------------------------------------------------*/
953 static void positionRegs (symbol *result, symbol *opsym, int lineno)
955 int count = min(result->nRegs,opsym->nRegs);
956 int i , j = 0, shared = 0;
958 /* if the result has been spilt then cannot share */
963 /* first make sure that they actually share */
964 for ( i = 0 ; i < count; i++ ) {
965 for (j = 0 ; j < count ; j++ ) {
966 if (result->regs[i] == opsym->regs[j] && i !=j) {
974 regs *tmp = result->regs[i];
975 result->regs[i] = result->regs[j];
976 result->regs[j] = tmp;
981 /*-----------------------------------------------------------------*/
982 /* serialRegAssign - serially allocate registers to the variables */
983 /*-----------------------------------------------------------------*/
984 static void serialRegAssign (eBBlock **ebbs, int count)
989 for (i = 0; i < count ; i++ ) {
993 if (ebbs[i]->noPath &&
994 (ebbs[i]->entryLabel != entryLabel &&
995 ebbs[i]->entryLabel != returnLabel ))
998 /* of all instructions do */
999 for (ic = ebbs[i]->sch ; ic ; ic = ic->next) {
1001 /* if this is an ipop that means some live
1002 range will have to be assigned again */
1004 reassignLR (IC_LEFT(ic));
1006 /* if result is present && is a true symbol */
1007 if (IC_RESULT(ic) && ic->op != IFX &&
1008 IS_TRUE_SYMOP(IC_RESULT(ic)))
1009 OP_SYMBOL(IC_RESULT(ic))->allocreq = 1;
1011 /* take away registers from live
1012 ranges that end at this instruction */
1013 deassignLRs (ic, ebbs[i]) ;
1015 /* some don't need registers */
1017 ic->op == JUMPTABLE ||
1021 (IC_RESULT(ic) &&POINTER_SET(ic)) )
1024 /* now we need to allocate registers
1025 only for the result */
1026 if (IC_RESULT(ic)) {
1027 symbol *sym = OP_SYMBOL(IC_RESULT(ic));
1033 /* if it does not need or is spilt
1034 or is already assigned to registers
1035 or will not live beyond this instructions */
1038 bitVectBitValue(_G.regAssigned,sym->key) ||
1039 sym->liveTo <= ic->seq)
1042 /* if some liverange has been spilt at the block level
1043 and this one live beyond this block then spil this
1045 if (_G.blockSpil && sym->liveTo > ebbs[i]->lSeq) {
1049 /* if trying to allocate this will cause
1050 a spill and there is nothing to spill
1051 or this one is rematerializable then
1053 willCS = willCauseSpill(sym->nRegs,sym->regType);
1054 spillable = computeSpillable(ic);
1056 (willCS && bitVectIsZero(spillable) ) ) {
1063 /* if it has a spillocation & is used less than
1064 all other live ranges then spill this */
1065 if ( willCS && sym->usl.spillLoc ) {
1068 leastUsedLR(liveRangesWith (spillable ,
1073 leastUsed->used > sym->used) {
1079 /* if we need ptr regs for the right side
1081 if (POINTER_GET(ic) && getSize(OP_SYMBOL(IC_LEFT(ic))->type)
1087 /* else we assign registers to it */
1088 _G.regAssigned = bitVectSetBit(_G.regAssigned,sym->key);
1090 for (j = 0 ; j < sym->nRegs ;j++ ) {
1091 if (sym->regType == REG_PTR)
1092 sym->regs[j] = getRegPtr(ic,ebbs[i],sym);
1094 sym->regs[j] = getRegGpr(ic,ebbs[i],sym);
1096 /* if the allocation falied which means
1097 this was spilt then break */
1101 /* if it shares registers with operands make sure
1102 that they are in the same position */
1103 if (IC_LEFT(ic) && IS_SYMOP(IC_LEFT(ic)) &&
1104 OP_SYMBOL(IC_LEFT(ic))->nRegs && ic->op != '=')
1105 positionRegs(OP_SYMBOL(IC_RESULT(ic)),
1106 OP_SYMBOL(IC_LEFT(ic)),ic->lineno);
1107 /* do the same for the right operand */
1108 if (IC_RIGHT(ic) && IS_SYMOP(IC_RIGHT(ic)) &&
1109 OP_SYMBOL(IC_RIGHT(ic))->nRegs)
1110 positionRegs(OP_SYMBOL(IC_RESULT(ic)),
1111 OP_SYMBOL(IC_RIGHT(ic)),ic->lineno);
1123 /*-----------------------------------------------------------------*/
1124 /* rUmaskForOp :- returns register mask for an operand */
1125 /*-----------------------------------------------------------------*/
1126 static bitVect *rUmaskForOp (operand *op)
1132 /* only temporaries are assigned registers */
1136 sym = OP_SYMBOL(op);
1138 /* if spilt or no registers assigned to it
1140 if (sym->isspilt || !sym->nRegs)
1143 rumask = newBitVect(ds390_nRegs);
1145 for (j = 0; j < sym->nRegs; j++) {
1146 rumask = bitVectSetBit(rumask,
1147 sym->regs[j]->rIdx);
1153 /*-----------------------------------------------------------------*/
1154 /* regsUsedIniCode :- returns bit vector of registers used in iCode*/
1155 /*-----------------------------------------------------------------*/
1156 static bitVect *regsUsedIniCode (iCode *ic)
1158 bitVect *rmask = newBitVect(ds390_nRegs);
1160 /* do the special cases first */
1161 if (ic->op == IFX ) {
1162 rmask = bitVectUnion(rmask,
1163 rUmaskForOp(IC_COND(ic)));
1167 /* for the jumptable */
1168 if (ic->op == JUMPTABLE) {
1169 rmask = bitVectUnion(rmask,
1170 rUmaskForOp(IC_JTCOND(ic)));
1175 /* of all other cases */
1177 rmask = bitVectUnion(rmask,
1178 rUmaskForOp(IC_LEFT(ic)));
1182 rmask = bitVectUnion(rmask,
1183 rUmaskForOp(IC_RIGHT(ic)));
1186 rmask = bitVectUnion(rmask,
1187 rUmaskForOp(IC_RESULT(ic)));
1193 /*-----------------------------------------------------------------*/
1194 /* createRegMask - for each instruction will determine the regsUsed*/
1195 /*-----------------------------------------------------------------*/
1196 static void createRegMask (eBBlock **ebbs, int count)
1200 /* for all blocks */
1201 for (i = 0; i < count ; i++ ) {
1204 if ( ebbs[i]->noPath &&
1205 ( ebbs[i]->entryLabel != entryLabel &&
1206 ebbs[i]->entryLabel != returnLabel ))
1209 /* for all instructions */
1210 for ( ic = ebbs[i]->sch ; ic ; ic = ic->next ) {
1214 if (SKIP_IC2(ic) || !ic->rlive)
1217 /* first mark the registers used in this
1219 ic->rUsed = regsUsedIniCode(ic);
1220 _G.funcrUsed = bitVectUnion(_G.funcrUsed,ic->rUsed);
1222 /* now create the register mask for those
1223 registers that are in use : this is a
1224 super set of ic->rUsed */
1225 ic->rMask = newBitVect(ds390_nRegs+1);
1227 /* for all live Ranges alive at this point */
1228 for (j = 1; j < ic->rlive->size; j++ ) {
1232 /* if not alive then continue */
1233 if (!bitVectBitValue(ic->rlive,j))
1236 /* find the live range we are interested in */
1237 if (!(sym = hTabItemWithKey(liveRanges,j))) {
1238 werror (E_INTERNAL_ERROR,__FILE__,__LINE__,
1239 "createRegMask cannot find live range");
1243 /* if no register assigned to it */
1244 if (!sym->nRegs || sym->isspilt)
1247 /* for all the registers allocated to it */
1248 for (k = 0 ; k < sym->nRegs ;k++)
1251 bitVectSetBit(ic->rMask,sym->regs[k]->rIdx);
1257 /*-----------------------------------------------------------------*/
1258 /* rematStr - returns the rematerialized string for a remat var */
1259 /*-----------------------------------------------------------------*/
1260 static char *rematStr (symbol *sym)
1263 iCode *ic = sym->rematiCode;
1267 /* if plus or minus print the right hand side */
1268 if (ic->op == '+' || ic->op == '-') {
1269 sprintf(s,"0x%04x %c ",(int) operandLitValue(IC_RIGHT(ic)),
1272 ic = OP_SYMBOL(IC_LEFT(ic))->rematiCode;
1276 /* we reached the end */
1277 sprintf(s,"%s",OP_SYMBOL(IC_LEFT(ic))->rname);
1284 /*-----------------------------------------------------------------*/
1285 /* regTypeNum - computes the type & number of registers required */
1286 /*-----------------------------------------------------------------*/
1287 static void regTypeNum ()
1293 /* for each live range do */
1294 for ( sym = hTabFirstItem(liveRanges,&k); sym ;
1295 sym = hTabNextItem(liveRanges,&k)) {
1297 /* if used zero times then no registers needed */
1298 if ((sym->liveTo - sym->liveFrom) == 0)
1302 /* if the live range is a temporary */
1305 /* if the type is marked as a conditional */
1306 if (sym->regType == REG_CND)
1309 /* if used in return only then we don't
1311 if (sym->ruonly || sym->accuse) {
1312 if (IS_AGGREGATE(sym->type) || sym->isptr)
1313 sym->type = aggrToPtr(sym->type,FALSE);
1317 /* if the symbol has only one definition &
1318 that definition is a get_pointer and the
1319 pointer we are getting is rematerializable and
1322 if (bitVectnBitsOn(sym->defs) == 1 &&
1323 (ic = hTabItemWithKey(iCodehTab,
1324 bitVectFirstBit(sym->defs))) &&
1326 !IS_BITVAR(sym->etype)) {
1329 /* if remat in data space */
1330 if (OP_SYMBOL(IC_LEFT(ic))->remat &&
1332 DCL_TYPE(aggrToPtr(sym->type,FALSE)) == POINTER) {
1334 /* create a psuedo symbol & force a spil */
1335 symbol *psym = newSymbol(rematStr(OP_SYMBOL(IC_LEFT(ic))),1);
1336 psym->type = sym->type;
1337 psym->etype = sym->etype;
1338 strcpy(psym->rname,psym->name);
1340 sym->usl.spillLoc = psym;
1344 /* if in data space or idata space then try to
1345 allocate pointer register */
1349 /* if not then we require registers */
1350 sym->nRegs = ((IS_AGGREGATE(sym->type) || sym->isptr ) ?
1351 getSize(sym->type = aggrToPtr(sym->type,FALSE)) :
1352 getSize(sym->type));
1354 if (sym->nRegs > 4) {
1355 fprintf(stderr,"allocated more than 4 or 0 registers for type ");
1356 printTypeChain(sym->type,stderr);fprintf(stderr,"\n");
1359 /* determine the type of register required */
1360 if (sym->nRegs == 1 &&
1361 IS_PTR(sym->type) &&
1363 sym->regType = REG_PTR ;
1365 sym->regType = REG_GPR ;
1368 /* for the first run we don't provide */
1369 /* registers for true symbols we will */
1370 /* see how things go */
1376 /*-----------------------------------------------------------------*/
1377 /* freeAllRegs - mark all registers as free */
1378 /*-----------------------------------------------------------------*/
1379 static void freeAllRegs()
1383 for (i=0;i< ds390_nRegs;i++ )
1384 regs390[i].isFree = 1;
1387 /*-----------------------------------------------------------------*/
1388 /* deallocStackSpil - this will set the stack pointer back */
1389 /*-----------------------------------------------------------------*/
1390 static DEFSETFUNC(deallocStackSpil)
1398 /*-----------------------------------------------------------------*/
1399 /* farSpacePackable - returns the packable icode for far variables */
1400 /*-----------------------------------------------------------------*/
1401 static iCode *farSpacePackable (iCode *ic)
1405 /* go thru till we find a definition for the
1406 symbol on the right */
1407 for ( dic = ic->prev ; dic ; dic = dic->prev) {
1409 /* if the definition is a call then no */
1410 if ((dic->op == CALL || dic->op == PCALL) &&
1411 IC_RESULT(dic)->key == IC_RIGHT(ic)->key) {
1415 /* if shift by unknown amount then not */
1416 if ((dic->op == LEFT_OP || dic->op == RIGHT_OP) &&
1417 IC_RESULT(dic)->key == IC_RIGHT(ic)->key)
1420 /* if pointer get and size > 1 */
1421 if (POINTER_GET(dic) &&
1422 getSize(aggrToPtr(operandType(IC_LEFT(dic)),FALSE)) > 1)
1425 if (POINTER_SET(dic) &&
1426 getSize(aggrToPtr(operandType(IC_RESULT(dic)),FALSE)) > 1)
1429 /* if any three is a true symbol in far space */
1430 if (IC_RESULT(dic) &&
1431 IS_TRUE_SYMOP(IC_RESULT(dic)) &&
1432 isOperandInFarSpace(IC_RESULT(dic)))
1435 if (IC_RIGHT(dic) &&
1436 IS_TRUE_SYMOP(IC_RIGHT(dic)) &&
1437 isOperandInFarSpace(IC_RIGHT(dic)) &&
1438 !isOperandEqual(IC_RIGHT(dic),IC_RESULT(ic)))
1442 IS_TRUE_SYMOP(IC_LEFT(dic)) &&
1443 isOperandInFarSpace(IC_LEFT(dic)) &&
1444 !isOperandEqual(IC_LEFT(dic),IC_RESULT(ic)))
1447 if (isOperandEqual(IC_RIGHT(ic),IC_RESULT(dic))) {
1448 if ( (dic->op == LEFT_OP ||
1449 dic->op == RIGHT_OP ||
1451 IS_OP_LITERAL(IC_RIGHT(dic)))
1461 /*-----------------------------------------------------------------*/
1462 /* packRegsForAssign - register reduction for assignment */
1463 /*-----------------------------------------------------------------*/
1464 static int packRegsForAssign (iCode *ic,eBBlock *ebp)
1468 if (!IS_ITEMP(IC_RIGHT(ic)) ||
1469 OP_SYMBOL(IC_RIGHT(ic))->isind ||
1470 OP_LIVETO(IC_RIGHT(ic)) > ic->seq) {
1474 /* if the true symbol is defined in far space or on stack
1475 then we should not since this will increase register pressure */
1476 if (isOperandInFarSpace(IC_RESULT(ic))) {
1477 if ((dic = farSpacePackable(ic)))
1483 /* find the definition of iTempNN scanning backwards if we find a
1484 a use of the true symbol in before we find the definition then
1486 for ( dic = ic->prev ; dic ; dic = dic->prev) {
1488 /* if there is a function call and this is
1489 a parameter & not my parameter then don't pack it */
1490 if ( (dic->op == CALL || dic->op == PCALL) &&
1491 (OP_SYMBOL(IC_RESULT(ic))->_isparm &&
1492 !OP_SYMBOL(IC_RESULT(ic))->ismyparm)) {
1500 if (IS_TRUE_SYMOP(IC_RESULT(dic)) &&
1501 IS_OP_VOLATILE(IC_RESULT(dic))) {
1506 if (IS_SYMOP(IC_RESULT(dic)) &&
1507 IC_RESULT(dic)->key == IC_RIGHT(ic)->key) {
1508 if (POINTER_SET(dic))
1514 if (IS_SYMOP(IC_RIGHT(dic)) &&
1515 (IC_RIGHT(dic)->key == IC_RESULT(ic)->key ||
1516 IC_RIGHT(dic)->key == IC_RIGHT(ic)->key)) {
1521 if (IS_SYMOP(IC_LEFT(dic)) &&
1522 (IC_LEFT(dic)->key == IC_RESULT(ic)->key ||
1523 IC_LEFT(dic)->key == IC_RIGHT(ic)->key)) {
1528 if (POINTER_SET(dic) &&
1529 IC_RESULT(dic)->key == IC_RESULT(ic)->key ) {
1536 return 0 ; /* did not find */
1538 /* if the result is on stack or iaccess then it must be
1539 the same atleast one of the operands */
1540 if (OP_SYMBOL(IC_RESULT(ic))->onStack ||
1541 OP_SYMBOL(IC_RESULT(ic))->iaccess ) {
1543 /* the operation has only one symbol
1544 operator then we can pack */
1545 if ((IC_LEFT(dic) && !IS_SYMOP(IC_LEFT(dic))) ||
1546 (IC_RIGHT(dic) && !IS_SYMOP(IC_RIGHT(dic))))
1549 if (!((IC_LEFT(dic) &&
1550 IC_RESULT(ic)->key == IC_LEFT(dic)->key) ||
1552 IC_RESULT(ic)->key == IC_RIGHT(dic)->key)))
1556 /* found the definition */
1557 /* replace the result with the result of */
1558 /* this assignment and remove this assignment */
1559 IC_RESULT(dic) = IC_RESULT(ic) ;
1561 if (IS_ITEMP(IC_RESULT(dic)) && OP_SYMBOL(IC_RESULT(dic))->liveFrom > dic->seq) {
1562 OP_SYMBOL(IC_RESULT(dic))->liveFrom = dic->seq;
1564 /* delete from liverange table also
1565 delete from all the points inbetween and the new
1567 for ( sic = dic; sic != ic ; sic = sic->next ) {
1568 bitVectUnSetBit(sic->rlive,IC_RESULT(ic)->key);
1569 if (IS_ITEMP(IC_RESULT(dic)))
1570 bitVectSetBit(sic->rlive,IC_RESULT(dic)->key);
1573 remiCodeFromeBBlock(ebp,ic);
1574 hTabDeleteItem (&iCodehTab,ic->key,ic,DELETE_ITEM,NULL);
1575 OP_DEFS(IC_RESULT(dic)) = bitVectSetBit(OP_DEFS(IC_RESULT(dic)),dic->key);
1580 /*-----------------------------------------------------------------*/
1581 /* findAssignToSym : scanning backwards looks for first assig found*/
1582 /*-----------------------------------------------------------------*/
1583 static iCode *findAssignToSym (operand *op,iCode *ic)
1587 for (dic = ic->prev ; dic ; dic = dic->prev) {
1589 /* if definition by assignment */
1590 if (dic->op == '=' &&
1591 !POINTER_SET(dic) &&
1592 IC_RESULT(dic)->key == op->key
1593 /* && IS_TRUE_SYMOP(IC_RIGHT(dic)) */
1596 /* we are interested only if defined in far space */
1597 /* or in stack space in case of + & - */
1599 /* if assigned to a non-symbol then return
1601 if (!IS_SYMOP(IC_RIGHT(dic)))
1604 /* if the symbol is in far space then
1606 if (isOperandInFarSpace(IC_RIGHT(dic)))
1609 /* for + & - operations make sure that
1610 if it is on the stack it is the same
1611 as one of the three operands */
1612 if ((ic->op == '+' || ic->op == '-') &&
1613 OP_SYMBOL(IC_RIGHT(dic))->onStack) {
1615 if ( IC_RESULT(ic)->key != IC_RIGHT(dic)->key &&
1616 IC_LEFT(ic)->key != IC_RIGHT(dic)->key &&
1617 IC_RIGHT(ic)->key != IC_RIGHT(dic)->key)
1625 /* if we find an usage then we cannot delete it */
1626 if (IC_LEFT(dic) && IC_LEFT(dic)->key == op->key)
1629 if (IC_RIGHT(dic) && IC_RIGHT(dic)->key == op->key)
1632 if (POINTER_SET(dic) && IC_RESULT(dic)->key == op->key)
1636 /* now make sure that the right side of dic
1637 is not defined between ic & dic */
1639 iCode *sic = dic->next ;
1641 for (; sic != ic ; sic = sic->next)
1642 if (IC_RESULT(sic) &&
1643 IC_RESULT(sic)->key == IC_RIGHT(dic)->key)
1652 /*-----------------------------------------------------------------*/
1653 /* packRegsForSupport :- reduce some registers for support calls */
1654 /*-----------------------------------------------------------------*/
1655 static int packRegsForSupport (iCode *ic, eBBlock *ebp)
1658 /* for the left & right operand :- look to see if the
1659 left was assigned a true symbol in far space in that
1660 case replace them */
1661 if (IS_ITEMP(IC_LEFT(ic)) &&
1662 OP_SYMBOL(IC_LEFT(ic))->liveTo <= ic->seq) {
1663 iCode *dic = findAssignToSym(IC_LEFT(ic),ic);
1669 /* found it we need to remove it from the
1671 for ( sic = dic; sic != ic ; sic = sic->next )
1672 bitVectUnSetBit(sic->rlive,IC_LEFT(ic)->key);
1674 IC_LEFT(ic)->operand.symOperand =
1675 IC_RIGHT(dic)->operand.symOperand;
1676 IC_LEFT(ic)->key = IC_RIGHT(dic)->operand.symOperand->key;
1677 remiCodeFromeBBlock(ebp,dic);
1678 hTabDeleteItem (&iCodehTab,dic->key,dic,DELETE_ITEM,NULL);
1682 /* do the same for the right operand */
1685 IS_ITEMP(IC_RIGHT(ic)) &&
1686 OP_SYMBOL(IC_RIGHT(ic))->liveTo <= ic->seq) {
1687 iCode *dic = findAssignToSym(IC_RIGHT(ic),ic);
1693 /* if this is a subtraction & the result
1694 is a true symbol in far space then don't pack */
1695 if (ic->op == '-' && IS_TRUE_SYMOP(IC_RESULT(dic))) {
1696 link *etype =getSpec(operandType(IC_RESULT(dic)));
1697 if (IN_FARSPACE(SPEC_OCLS(etype)))
1700 /* found it we need to remove it from the
1702 for ( sic = dic; sic != ic ; sic = sic->next )
1703 bitVectUnSetBit(sic->rlive,IC_RIGHT(ic)->key);
1705 IC_RIGHT(ic)->operand.symOperand =
1706 IC_RIGHT(dic)->operand.symOperand;
1707 IC_RIGHT(ic)->key = IC_RIGHT(dic)->operand.symOperand->key;
1709 remiCodeFromeBBlock(ebp,dic);
1710 hTabDeleteItem (&iCodehTab,dic->key,dic,DELETE_ITEM,NULL);
1717 #define IS_OP_RUONLY(x) (x && IS_SYMOP(x) && OP_SYMBOL(x)->ruonly)
1720 /*-----------------------------------------------------------------*/
1721 /* packRegsForOneuse : - will reduce some registers for single Use */
1722 /*-----------------------------------------------------------------*/
1723 static iCode *packRegsForOneuse (iCode *ic, operand *op , eBBlock *ebp)
1728 /* if returning a literal then do nothing */
1732 /* only upto 2 bytes since we cannot predict
1733 the usage of b, & acc */
1734 if (getSize(operandType(op)) > (fReturnSize_390 - 2) &&
1741 /* this routine will mark the a symbol as used in one
1742 instruction use only && if the defintion is local
1743 (ie. within the basic block) && has only one definition &&
1744 that definiion is either a return value from a
1745 function or does not contain any variables in
1747 uses = bitVectCopy(OP_USES(op));
1748 bitVectUnSetBit(uses,ic->key); /* take away this iCode */
1749 if (!bitVectIsZero(uses)) /* has other uses */
1752 /* if it has only one defintion */
1753 if (bitVectnBitsOn(OP_DEFS(op)) > 1)
1754 return NULL ; /* has more than one definition */
1756 /* get the that definition */
1758 hTabItemWithKey(iCodehTab,
1759 bitVectFirstBit(OP_DEFS(op)))))
1762 /* found the definition now check if it is local */
1763 if (dic->seq < ebp->fSeq ||
1764 dic->seq > ebp->lSeq)
1765 return NULL ; /* non-local */
1767 /* now check if it is the return from
1769 if (dic->op == CALL || dic->op == PCALL ) {
1770 if (ic->op != SEND && ic->op != RETURN) {
1771 OP_SYMBOL(op)->ruonly = 1;
1778 /* otherwise check that the definition does
1779 not contain any symbols in far space */
1780 if (isOperandInFarSpace(IC_LEFT(dic)) ||
1781 isOperandInFarSpace(IC_RIGHT(dic)) ||
1782 IS_OP_RUONLY(IC_LEFT(ic)) ||
1783 IS_OP_RUONLY(IC_RIGHT(ic)) ) {
1787 /* if pointer set then make sure the pointer
1789 if (POINTER_SET(dic) &&
1790 !IS_DATA_PTR(aggrToPtr(operandType(IC_RESULT(dic)),FALSE)))
1793 if (POINTER_GET(dic) &&
1794 !IS_DATA_PTR(aggrToPtr(operandType(IC_LEFT(dic)),FALSE)))
1799 /* also make sure the intervenening instructions
1800 don't have any thing in far space */
1801 for (dic = dic->next ; dic && dic != ic ; dic = dic->next) {
1803 /* if there is an intervening function call then no */
1804 if (dic->op == CALL || dic->op == PCALL)
1806 /* if pointer set then make sure the pointer
1808 if (POINTER_SET(dic) &&
1809 !IS_DATA_PTR(aggrToPtr(operandType(IC_RESULT(dic)),FALSE)))
1812 if (POINTER_GET(dic) &&
1813 !IS_DATA_PTR(aggrToPtr(operandType(IC_LEFT(dic)),FALSE)))
1816 /* if address of & the result is remat the okay */
1817 if (dic->op == ADDRESS_OF &&
1818 OP_SYMBOL(IC_RESULT(dic))->remat)
1821 /* if operand has size of three or more & this
1822 operation is a '*','/' or '%' then 'b' may
1824 if (( dic->op == '%' || dic->op == '/' || dic->op == '*') &&
1825 getSize(operandType(op)) >= 3)
1828 /* if left or right or result is in far space */
1829 if (isOperandInFarSpace(IC_LEFT(dic)) ||
1830 isOperandInFarSpace(IC_RIGHT(dic)) ||
1831 isOperandInFarSpace(IC_RESULT(dic)) ||
1832 IS_OP_RUONLY(IC_LEFT(dic)) ||
1833 IS_OP_RUONLY(IC_RIGHT(dic)) ||
1834 IS_OP_RUONLY(IC_RESULT(dic)) ) {
1839 OP_SYMBOL(op)->ruonly = 1;
1844 /*-----------------------------------------------------------------*/
1845 /* isBitwiseOptimizable - requirements of JEAN LOUIS VERN */
1846 /*-----------------------------------------------------------------*/
1847 static bool isBitwiseOptimizable (iCode *ic)
1849 link *ltype = getSpec(operandType(IC_LEFT(ic)));
1850 link *rtype = getSpec(operandType(IC_RIGHT(ic)));
1852 /* bitwise operations are considered optimizable
1853 under the following conditions (Jean-Louis VERN)
1865 if ( IS_LITERAL(rtype) ||
1866 (IS_BITVAR(ltype) && IN_BITSPACE(SPEC_OCLS(ltype))))
1872 /*-----------------------------------------------------------------*/
1873 /* packRegsForAccUse - pack registers for acc use */
1874 /*-----------------------------------------------------------------*/
1875 static void packRegsForAccUse (iCode *ic)
1879 /* if + or - then it has to be one byte result */
1880 if ((ic->op == '+' || ic->op == '-')
1881 && getSize(operandType(IC_RESULT(ic))) > 1)
1884 /* if shift operation make sure right side is not a literal */
1885 if (ic->op == RIGHT_OP &&
1886 ( isOperandLiteral(IC_RIGHT(ic)) ||
1887 getSize(operandType(IC_RESULT(ic))) > 1))
1890 if (ic->op == LEFT_OP &&
1891 ( isOperandLiteral(IC_RIGHT(ic)) ||
1892 getSize(operandType(IC_RESULT(ic))) > 1))
1895 if (IS_BITWISE_OP(ic) &&
1896 getSize(operandType(IC_RESULT(ic))) > 1)
1900 /* has only one definition */
1901 if (bitVectnBitsOn(OP_DEFS(IC_RESULT(ic))) > 1)
1904 /* has only one use */
1905 if (bitVectnBitsOn(OP_USES(IC_RESULT(ic))) > 1)
1908 /* and the usage immediately follows this iCode */
1909 if (!(uic = hTabItemWithKey(iCodehTab,
1910 bitVectFirstBit(OP_USES(IC_RESULT(ic))))))
1913 if (ic->next != uic)
1916 /* if it is a conditional branch then we definitely can */
1917 if (uic->op == IFX )
1920 if ( uic->op == JUMPTABLE )
1923 /* if the usage is not is an assignment
1924 or an arithmetic / bitwise / shift operation then not */
1925 if (POINTER_SET(uic) &&
1926 getSize(aggrToPtr(operandType(IC_RESULT(uic)),FALSE)) > 1)
1929 if (uic->op != '=' &&
1930 !IS_ARITHMETIC_OP(uic) &&
1931 !IS_BITWISE_OP(uic) &&
1932 uic->op != LEFT_OP &&
1933 uic->op != RIGHT_OP )
1936 /* if used in ^ operation then make sure right is not a
1938 if (uic->op == '^' && isOperandLiteral(IC_RIGHT(uic)))
1941 /* if shift operation make sure right side is not a literal */
1942 if (uic->op == RIGHT_OP &&
1943 ( isOperandLiteral(IC_RIGHT(uic)) ||
1944 getSize(operandType(IC_RESULT(uic))) > 1))
1947 if (uic->op == LEFT_OP &&
1948 ( isOperandLiteral(IC_RIGHT(uic)) ||
1949 getSize(operandType(IC_RESULT(uic))) > 1))
1952 /* make sure that the result of this icode is not on the
1953 stack, since acc is used to compute stack offset */
1954 if (IS_TRUE_SYMOP(IC_RESULT(uic)) &&
1955 OP_SYMBOL(IC_RESULT(uic))->onStack)
1958 /* if either one of them in far space then we cannot */
1959 if ((IS_TRUE_SYMOP(IC_LEFT(uic)) &&
1960 isOperandInFarSpace(IC_LEFT(uic))) ||
1961 (IS_TRUE_SYMOP(IC_RIGHT(uic)) &&
1962 isOperandInFarSpace(IC_RIGHT(uic))))
1965 /* if the usage has only one operand then we can */
1966 if (IC_LEFT(uic) == NULL ||
1967 IC_RIGHT(uic) == NULL)
1970 /* make sure this is on the left side if not
1971 a '+' since '+' is commutative */
1972 if (ic->op != '+' &&
1973 IC_LEFT(uic)->key != IC_RESULT(ic)->key)
1976 /* if one of them is a literal then we can */
1977 if ((IC_LEFT(uic) && IS_OP_LITERAL(IC_LEFT(uic))) ||
1978 (IC_RIGHT(uic) && IS_OP_LITERAL(IC_RIGHT(uic)))) {
1979 OP_SYMBOL(IC_RESULT(ic))->accuse = 1;
1983 /* if the other one is not on stack then we can */
1984 if (IC_LEFT(uic)->key == IC_RESULT(ic)->key &&
1985 (IS_ITEMP(IC_RIGHT(uic)) ||
1986 (IS_TRUE_SYMOP(IC_RIGHT(uic)) &&
1987 !OP_SYMBOL(IC_RIGHT(uic))->onStack)))
1990 if (IC_RIGHT(uic)->key == IC_RESULT(ic)->key &&
1991 (IS_ITEMP(IC_LEFT(uic)) ||
1992 (IS_TRUE_SYMOP(IC_LEFT(uic)) &&
1993 !OP_SYMBOL(IC_LEFT(uic))->onStack)))
1999 OP_SYMBOL(IC_RESULT(ic))->accuse = 1;
2004 /*-----------------------------------------------------------------*/
2005 /* packForPush - hueristics to reduce iCode for pushing */
2006 /*-----------------------------------------------------------------*/
2007 static void packForPush(iCode *ic, eBBlock *ebp)
2011 if (ic->op != IPUSH || !IS_ITEMP(IC_LEFT(ic)))
2014 /* must have only definition & one usage */
2015 if (bitVectnBitsOn(OP_DEFS(IC_LEFT(ic))) != 1 ||
2016 bitVectnBitsOn(OP_USES(IC_LEFT(ic))) != 1 )
2019 /* find the definition */
2020 if (!(dic = hTabItemWithKey(iCodehTab,
2021 bitVectFirstBit(OP_DEFS(IC_LEFT(ic))))))
2024 if (dic->op != '=' || POINTER_SET(dic))
2027 /* we now we know that it has one & only one def & use
2028 and the that the definition is an assignment */
2029 IC_LEFT(ic) = IC_RIGHT(dic);
2031 remiCodeFromeBBlock(ebp,dic);
2032 hTabDeleteItem (&iCodehTab,dic->key,dic,DELETE_ITEM,NULL);
2035 /*-----------------------------------------------------------------*/
2036 /* packRegisters - does some transformations to reduce register */
2038 /*-----------------------------------------------------------------*/
2039 static void packRegisters (eBBlock *ebp)
2048 /* look for assignments of the form */
2049 /* iTempNN = TRueSym (someoperation) SomeOperand */
2051 /* TrueSym := iTempNN:1 */
2052 for ( ic = ebp->sch ; ic ; ic = ic->next ) {
2055 /* find assignment of the form TrueSym := iTempNN:1 */
2056 if (ic->op == '=' && !POINTER_SET(ic))
2057 change += packRegsForAssign(ic,ebp);
2064 for ( ic = ebp->sch ; ic ; ic = ic->next ) {
2066 /* if this is an itemp & result of a address of a true sym
2067 then mark this as rematerialisable */
2068 if (ic->op == ADDRESS_OF &&
2069 IS_ITEMP(IC_RESULT(ic)) &&
2070 IS_TRUE_SYMOP(IC_LEFT(ic)) &&
2071 bitVectnBitsOn(OP_DEFS(IC_RESULT(ic))) == 1 &&
2072 !OP_SYMBOL(IC_LEFT(ic))->onStack ) {
2074 OP_SYMBOL(IC_RESULT(ic))->remat = 1;
2075 OP_SYMBOL(IC_RESULT(ic))->rematiCode = ic;
2076 OP_SYMBOL(IC_RESULT(ic))->usl.spillLoc = NULL;
2080 /* if straight assignment then carry remat flag if
2081 this is the only definition */
2082 if (ic->op == '=' &&
2084 IS_SYMOP(IC_RIGHT(ic)) &&
2085 OP_SYMBOL(IC_RIGHT(ic))->remat &&
2086 bitVectnBitsOn(OP_SYMBOL(IC_RESULT(ic))->defs) <= 1) {
2088 OP_SYMBOL(IC_RESULT(ic))->remat =
2089 OP_SYMBOL(IC_RIGHT(ic))->remat;
2090 OP_SYMBOL(IC_RESULT(ic))->rematiCode =
2091 OP_SYMBOL(IC_RIGHT(ic))->rematiCode ;
2094 /* if this is a +/- operation with a rematerizable
2095 then mark this as rematerializable as well */
2096 if ((ic->op == '+' || ic->op == '-') &&
2097 (IS_SYMOP(IC_LEFT(ic)) &&
2098 IS_ITEMP(IC_RESULT(ic)) &&
2099 OP_SYMBOL(IC_LEFT(ic))->remat &&
2100 bitVectnBitsOn(OP_DEFS(IC_RESULT(ic))) == 1 &&
2101 IS_OP_LITERAL(IC_RIGHT(ic))) ) {
2103 int i = operandLitValue(IC_RIGHT(ic));
2104 OP_SYMBOL(IC_RESULT(ic))->remat = 1;
2105 OP_SYMBOL(IC_RESULT(ic))->rematiCode = ic;
2106 OP_SYMBOL(IC_RESULT(ic))->usl.spillLoc = NULL;
2109 /* mark the pointer usages */
2110 if (POINTER_SET(ic))
2111 OP_SYMBOL(IC_RESULT(ic))->uptr = 1;
2113 if (POINTER_GET(ic))
2114 OP_SYMBOL(IC_LEFT(ic))->uptr = 1;
2116 if (!SKIP_IC2(ic)) {
2117 /* if we are using a symbol on the stack
2118 then we should say ds390_ptrRegReq */
2119 if (ic->op == IFX && IS_SYMOP(IC_COND(ic)))
2120 ds390_ptrRegReq += ((OP_SYMBOL(IC_COND(ic))->onStack ||
2121 OP_SYMBOL(IC_COND(ic))->iaccess) ? 1 : 0);
2123 if (ic->op == JUMPTABLE && IS_SYMOP(IC_JTCOND(ic)))
2124 ds390_ptrRegReq += ((OP_SYMBOL(IC_JTCOND(ic))->onStack ||
2125 OP_SYMBOL(IC_JTCOND(ic))->iaccess) ? 1 : 0);
2127 if (IS_SYMOP(IC_LEFT(ic)))
2128 ds390_ptrRegReq += ((OP_SYMBOL(IC_LEFT(ic))->onStack ||
2129 OP_SYMBOL(IC_LEFT(ic))->iaccess) ? 1 : 0);
2130 if (IS_SYMOP(IC_RIGHT(ic)))
2131 ds390_ptrRegReq += ((OP_SYMBOL(IC_RIGHT(ic))->onStack ||
2132 OP_SYMBOL(IC_RIGHT(ic))->iaccess) ? 1 : 0);
2133 if (IS_SYMOP(IC_RESULT(ic)))
2134 ds390_ptrRegReq += ((OP_SYMBOL(IC_RESULT(ic))->onStack ||
2135 OP_SYMBOL(IC_RESULT(ic))->iaccess) ? 1 : 0);
2139 /* if the condition of an if instruction
2140 is defined in the previous instruction then
2141 mark the itemp as a conditional */
2142 if ((IS_CONDITIONAL(ic) ||
2143 ( ( ic->op == BITWISEAND ||
2146 isBitwiseOptimizable(ic))) &&
2147 ic->next && ic->next->op == IFX &&
2148 isOperandEqual(IC_RESULT(ic),IC_COND(ic->next)) &&
2149 OP_SYMBOL(IC_RESULT(ic))->liveTo <= ic->next->seq) {
2151 OP_SYMBOL(IC_RESULT(ic))->regType = REG_CND;
2155 /* reduce for support function calls */
2156 if (ic->supportRtn || ic->op == '+' || ic->op == '-' )
2157 packRegsForSupport (ic,ebp);
2159 /* some cases the redundant moves can
2160 can be eliminated for return statements */
2161 if ((ic->op == RETURN || ic->op == SEND) &&
2162 !isOperandInFarSpace(IC_LEFT(ic)) &&
2164 packRegsForOneuse (ic,IC_LEFT(ic),ebp);
2166 /* if pointer set & left has a size more than
2167 one and right is not in far space */
2168 if (POINTER_SET(ic) &&
2169 !isOperandInFarSpace(IC_RIGHT(ic)) &&
2170 !OP_SYMBOL(IC_RESULT(ic))->remat &&
2171 !IS_OP_RUONLY(IC_RIGHT(ic)) &&
2172 getSize(aggrToPtr(operandType(IC_RESULT(ic)),FALSE)) > 1 )
2174 packRegsForOneuse (ic,IC_RESULT(ic),ebp);
2176 /* if pointer get */
2177 if (POINTER_GET(ic) &&
2178 !isOperandInFarSpace(IC_RESULT(ic))&&
2179 !OP_SYMBOL(IC_LEFT(ic))->remat &&
2180 !IS_OP_RUONLY(IC_RESULT(ic)) &&
2181 getSize(aggrToPtr(operandType(IC_LEFT(ic)),FALSE)) > 1 )
2183 packRegsForOneuse (ic,IC_LEFT(ic),ebp);
2186 /* if this is cast for intergral promotion then
2187 check if only use of the definition of the
2188 operand being casted/ if yes then replace
2189 the result of that arithmetic operation with
2190 this result and get rid of the cast */
2191 if (ic->op == CAST) {
2192 link *fromType = operandType(IC_RIGHT(ic));
2193 link *toType = operandType(IC_LEFT(ic));
2195 if (IS_INTEGRAL(fromType) && IS_INTEGRAL(toType) &&
2196 getSize(fromType) != getSize(toType) ) {
2198 iCode *dic = packRegsForOneuse(ic,IC_RIGHT(ic),ebp);
2200 if (IS_ARITHMETIC_OP(dic)) {
2201 IC_RESULT(dic) = IC_RESULT(ic);
2202 remiCodeFromeBBlock(ebp,ic);
2203 hTabDeleteItem (&iCodehTab,ic->key,ic,DELETE_ITEM,NULL);
2204 OP_DEFS(IC_RESULT(dic)) = bitVectSetBit(OP_DEFS(IC_RESULT(dic)),dic->key);
2207 OP_SYMBOL(IC_RIGHT(ic))->ruonly = 0;
2211 /* if the type from and type to are the same
2212 then if this is the only use then packit */
2213 if (checkType(operandType(IC_RIGHT(ic)),
2214 operandType(IC_LEFT(ic))) == 1) {
2215 iCode *dic = packRegsForOneuse (ic,IC_RIGHT(ic),ebp);
2217 IC_RESULT(dic) = IC_RESULT(ic);
2218 remiCodeFromeBBlock(ebp,ic);
2219 hTabDeleteItem (&iCodehTab,ic->key,ic,DELETE_ITEM,NULL);
2220 OP_DEFS(IC_RESULT(dic)) = bitVectSetBit(OP_DEFS(IC_RESULT(dic)),dic->key);
2228 iTempNN := (some variable in farspace) V1
2233 if (ic->op == IPUSH ) {
2234 packForPush(ic,ebp);
2238 /* pack registers for accumulator use, when the
2239 result of an arithmetic or bit wise operation
2240 has only one use, that use is immediately following
2241 the defintion and the using iCode has only one
2242 operand or has two operands but one is literal &
2243 the result of that operation is not on stack then
2244 we can leave the result of this operation in acc:b
2246 if ((IS_ARITHMETIC_OP(ic)
2248 || IS_BITWISE_OP(ic)
2250 || ic->op == LEFT_OP || ic->op == RIGHT_OP
2253 IS_ITEMP(IC_RESULT(ic)) &&
2254 getSize(operandType(IC_RESULT(ic))) <= 2)
2256 packRegsForAccUse (ic);
2261 /*-----------------------------------------------------------------*/
2262 /* assignRegisters - assigns registers to each live range as need */
2263 /*-----------------------------------------------------------------*/
2264 void ds390_assignRegisters (eBBlock **ebbs, int count)
2269 setToNull((void *)&_G.funcrUsed);
2270 ds390_ptrRegReq = _G.stackExtend = _G.dataExtend = 0;
2271 /* if not register extentions then reduce number
2273 if (options.regExtend)
2278 /* change assignments this will remove some
2279 live ranges reducing some register pressure */
2280 for (i = 0 ; i < count ;i++ )
2281 packRegisters (ebbs[i]);
2283 if (options.dump_pack)
2284 dumpEbbsToFileExt(".dumppack",ebbs,count);
2286 /* first determine for each live range the number of
2287 registers & the type of registers required for each */
2290 /* and serially allocate registers */
2291 serialRegAssign(ebbs,count);
2293 /* if stack was extended then tell the user */
2294 if (_G.stackExtend) {
2295 /* werror(W_TOOMANY_SPILS,"stack", */
2296 /* _G.stackExtend,currFunc->name,""); */
2297 _G.stackExtend = 0 ;
2300 if (_G.dataExtend) {
2301 /* werror(W_TOOMANY_SPILS,"data space", */
2302 /* _G.dataExtend,currFunc->name,""); */
2306 /* after that create the register mask
2307 for each of the instruction */
2308 createRegMask (ebbs,count);
2310 /* redo that offsets for stacked automatic variables */
2311 redoStackOffsets ();
2313 if (options.dump_rassgn)
2314 dumpEbbsToFileExt(".dumprassgn",ebbs,count);
2316 /* do the overlaysegment stuff SDCCmem.c */
2317 doOverlays(ebbs,count);
2319 /* now get back the chain */
2320 ic = iCodeLabelOptimize(iCodeFromeBBlock (ebbs,count));
2325 /* free up any _G.stackSpil locations allocated */
2326 applyToSet(_G.stackSpil,deallocStackSpil);
2328 setToNull((void **)&_G.stackSpil);
2329 setToNull((void **)&_G.spiltSet);
2330 /* mark all registers as free */