1 /*------------------------------------------------------------------------
3 SDCCralloc.c - source file for register allocation. (ATMEL AVR) 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 genAVRCode(iCode *);
48 bitVect *funcrUsed; /* registers used in a function */
53 /* Shared with gen.c */
54 int avr_ptrRegReq; /* pointer register required */
59 { REG_GPR ,R0_IDX , REG_GPR , "r0", "r0" , "" , 0, 1 },
60 { REG_GPR ,R1_IDX , REG_GPR , "r1", "r1" , "" , 0, 1 },
61 { REG_GPR ,R2_IDX , REG_GPR , "r2", "r2" , "" , 0, 1 },
62 { REG_GPR ,R3_IDX , REG_GPR , "r3", "r3" , "" , 0, 1 },
63 { REG_GPR ,R4_IDX , REG_GPR , "r4", "r4" , "" , 0, 1 },
64 { REG_GPR ,R5_IDX , REG_GPR , "r5", "r5" , "" , 0, 1 },
65 { REG_GPR ,R6_IDX , REG_GPR , "r6", "r6" , "" , 0, 1 },
66 { REG_GPR ,R7_IDX , REG_GPR , "r7", "r7" , "" , 0, 1 },
67 { REG_GPR ,R8_IDX , REG_GPR , "r8", "r8" , "" , 0, 1 },
68 { REG_GPR ,R9_IDX , REG_GPR , "r9", "r9" , "" , 0, 1 },
69 { REG_GPR ,R10_IDX, REG_GPR , "r10", "r10", "" , 0, 1 },
70 { REG_GPR ,R11_IDX, REG_GPR , "r11", "r11", "" , 0, 1 },
71 { REG_GPR ,R12_IDX, REG_GPR , "r12", "r12", "" , 0, 1 },
72 { REG_GPR ,R13_IDX, REG_GPR , "r13", "r13", "" , 0, 1 },
73 { REG_GPR ,R14_IDX, REG_GPR , "r14", "r14", "" , 0, 1 },
74 { REG_GPR ,R15_IDX, REG_GPR , "r15", "r15", "" , 0, 1 },
75 { REG_GPR ,R16_IDX, REG_GPR , "r16", "r16", "" , 0, 1 },
76 { REG_GPR ,R17_IDX, REG_GPR , "r17", "r17", "" , 0, 1 },
77 { REG_GPR ,R18_IDX, REG_GPR , "r18", "r18", "" , 0, 1 },
78 { REG_GPR ,R19_IDX, REG_GPR , "r19", "r19", "" , 0, 1 },
79 { REG_GPR ,R20_IDX, REG_GPR , "r20", "r20", "" , 0, 1 },
80 { REG_GPR ,R21_IDX, REG_GPR , "r21", "r21", "" , 0, 1 },
81 { REG_GPR ,R22_IDX, REG_GPR , "r22", "r22", "" , 0, 1 },
82 { REG_GPR ,R23_IDX, REG_GPR , "r23", "r23", "" , 0, 1 },
83 { REG_GPR ,R24_IDX, REG_GPR , "r24", "r24", "" , 0, 1 },
84 { REG_GPR ,R25_IDX, REG_GPR , "r25", "r25", "" , 0, 0 }, /* special literal use */
85 { REG_GPR ,R26_IDX, REG_GPR , "r26", "r26", "" , 0, 0 }, /* used as pointer reg */
86 { REG_GPR ,R27_IDX, REG_GPR , "r27", "r27", "" , 0, 0 },
87 { REG_GPR ,R28_IDX, REG_GPR , "r28", "r28", "" , 0, 0 },
88 { REG_GPR ,R29_IDX, REG_GPR , "r29", "r29", "" , 0, 0 },
89 { REG_GPR ,R30_IDX, REG_GPR , "r30", "r30", "" , 0, 0 },
90 { REG_GPR ,R31_IDX, REG_GPR , "r31", "r31", "" , 0, 0 },
91 { REG_PTR ,X_IDX , REG_PTR , "X" , "X" , "" , 0, 1 },
92 { REG_PTR ,Z_IDX , REG_PTR , "Z" , "Z" , "" , 0, 1 },
95 int avr_fReg = 8; /* first allocatable register */
97 static void spillThis (symbol *);
99 /*-----------------------------------------------------------------*/
100 /* allocReg - allocates register of given type */
101 /*-----------------------------------------------------------------*/
102 static regs *allocReg (short type)
106 /* if type is a pointer register then
108 if (type == REG_PTR) {
110 if (regsAVR[X_IDX].isFree) {
111 regsAVR[X_IDX].isFree = 0;
112 return ®sAVR[X_IDX];
114 if (regsAVR[Z_IDX].isFree ) {
115 regsAVR[Z_IDX].isFree = 0;
116 return ®sAVR[Z_IDX];
121 for ( i = avr_fReg ; i < avr_nRegs ; i++ ) {
123 /* if type is given as 0 then any
124 free register will do */
126 regsAVR[i].isFree ) {
127 regsAVR[i].isFree = 0;
130 bitVectSetBit(currFunc->regsUsed,i);
133 /* other wise look for specific type
135 if (regsAVR[i].isFree &&
136 regsAVR[i].type == type) {
137 regsAVR[i].isFree = 0;
140 bitVectSetBit(currFunc->regsUsed,i);
147 /*-----------------------------------------------------------------*/
148 /* avr_regWithIdx - returns pointer to register wit index number */
149 /*-----------------------------------------------------------------*/
150 regs *avr_regWithIdx (int idx)
154 for (i=0 ; i < avr_nRegs;i++)
155 if (regsAVR[i].rIdx == idx)
158 werror(E_INTERNAL_ERROR,__FILE__,__LINE__,
159 "regWithIdx not found");
163 /*-----------------------------------------------------------------*/
164 /* freeReg - frees a register */
165 /*-----------------------------------------------------------------*/
166 static void freeReg (regs *reg)
172 /*-----------------------------------------------------------------*/
173 /* nFreeRegs - returns number of free registers */
174 /*-----------------------------------------------------------------*/
175 static int nFreeRegs (int type)
180 for (i = avr_fReg ; i < avr_nRegs; i++ )
181 if (regsAVR[i].isFree && regsAVR[i].type == type)
186 /*-----------------------------------------------------------------*/
187 /* nfreeRegsType - free registers with type */
188 /*-----------------------------------------------------------------*/
189 static int nfreeRegsType (int type)
192 if (type == REG_PTR) {
193 if ((nfr = nFreeRegs(type)) == 0)
194 return nFreeRegs(REG_GPR);
197 return nFreeRegs(type);
201 /*-----------------------------------------------------------------*/
202 /* allDefsOutOfRange - all definitions are out of a range */
203 /*-----------------------------------------------------------------*/
204 static bool allDefsOutOfRange (bitVect *defs,int fseq, int toseq)
211 for ( i = 0 ;i < defs->size ; i++ ) {
214 if (bitVectBitValue(defs,i) &&
215 (ic = hTabItemWithKey(iCodehTab,i)) &&
216 ( ic->seq >= fseq && ic->seq <= toseq))
225 /*-----------------------------------------------------------------*/
226 /* computeSpillable - given a point find the spillable live ranges */
227 /*-----------------------------------------------------------------*/
228 static bitVect *computeSpillable (iCode *ic)
232 /* spillable live ranges are those that are live at this
233 point . the following categories need to be subtracted
235 a) - those that are already spilt
236 b) - if being used by this one
237 c) - defined by this one */
239 spillable = bitVectCopy(ic->rlive);
241 bitVectCplAnd(spillable,_G.spiltSet); /* those already spilt */
243 bitVectCplAnd(spillable,ic->uses); /* used in this one */
244 bitVectUnSetBit(spillable,ic->defKey);
245 spillable = bitVectIntersect(spillable,_G.regAssigned);
250 /*-----------------------------------------------------------------*/
251 /* noSpilLoc - return true if a variable has no spil location */
252 /*-----------------------------------------------------------------*/
253 static int noSpilLoc (symbol *sym, eBBlock *ebp,iCode *ic)
255 return (sym->usl.spillLoc ? 0 : 1);
258 /*-----------------------------------------------------------------*/
259 /* hasSpilLoc - will return 1 if the symbol has spil location */
260 /*-----------------------------------------------------------------*/
261 static int hasSpilLoc (symbol *sym, eBBlock *ebp, iCode *ic)
263 return (sym->usl.spillLoc ? 1 : 0);
266 /*-----------------------------------------------------------------*/
267 /* hasSpilLocnoUptr - will return 1 if the symbol has spil location*/
268 /* but is not used as a pointer */
269 /*-----------------------------------------------------------------*/
270 static int hasSpilLocnoUptr (symbol *sym, eBBlock *ebp, iCode *ic)
272 return ((sym->usl.spillLoc && !sym->uptr) ? 1 : 0);
275 /*-----------------------------------------------------------------*/
276 /* rematable - will return 1 if the remat flag is set */
277 /*-----------------------------------------------------------------*/
278 static int rematable (symbol *sym, eBBlock *ebp, iCode *ic)
283 /*-----------------------------------------------------------------*/
284 /* notUsedInBlock - not used in this block */
285 /*-----------------------------------------------------------------*/
286 static int notUsedInBlock (symbol *sym, eBBlock *ebp, iCode *ic)
288 return (!bitVectBitsInCommon(sym->defs,ebp->usesDefs) &&
289 allDefsOutOfRange (sym->defs,ebp->fSeq,ebp->lSeq));
292 /*-----------------------------------------------------------------*/
293 /* notUsedInRemaining - not used or defined in remain of the block */
294 /*-----------------------------------------------------------------*/
295 static int notUsedInRemaining (symbol *sym, eBBlock *ebp, iCode *ic)
297 return ((usedInRemaining (operandFromSymbol(sym),ic) ? 0 : 1) &&
298 allDefsOutOfRange (sym->defs,ic->seq,ebp->lSeq));
301 /*-----------------------------------------------------------------*/
302 /* allLRs - return true for all */
303 /*-----------------------------------------------------------------*/
304 static int allLRs (symbol *sym, eBBlock *ebp, iCode *ic)
309 /*-----------------------------------------------------------------*/
310 /* liveRangesWith - applies function to a given set of live range */
311 /*-----------------------------------------------------------------*/
312 static set *liveRangesWith (bitVect *lrs,
313 int (func)(symbol *,eBBlock *, iCode *),
314 eBBlock *ebp, iCode *ic)
319 if (!lrs || !lrs->size)
322 for ( i = 1 ; i < lrs->size ; i++ ) {
324 if (!bitVectBitValue(lrs,i))
327 /* if we don't find it in the live range
328 hash table we are in serious trouble */
329 if (!(sym = hTabItemWithKey(liveRanges,i))) {
330 werror(E_INTERNAL_ERROR,__FILE__,__LINE__,
331 "liveRangesWith could not find liveRange");
335 if (func(sym,ebp,ic) && bitVectBitValue(_G.regAssigned,sym->key))
336 addSetHead(&rset,sym);
343 /*-----------------------------------------------------------------*/
344 /* leastUsedLR - given a set determines which is the least used */
345 /*-----------------------------------------------------------------*/
346 static symbol *leastUsedLR (set *sset)
348 symbol *sym = NULL, *lsym = NULL ;
350 sym = lsym = setFirstItem(sset);
355 for (; lsym; lsym = setNextItem(sset)) {
357 /* if usage is the same then prefer
358 the spill the smaller of the two */
359 if ( lsym->used == sym->used )
360 if (getSize(lsym->type) < getSize(sym->type))
364 if (lsym->used < sym->used )
369 setToNull((void **)&sset);
374 /*-----------------------------------------------------------------*/
375 /* noOverLap - will iterate through the list looking for over lap */
376 /*-----------------------------------------------------------------*/
377 static int noOverLap (set *itmpStack, symbol *fsym)
382 for (sym = setFirstItem(itmpStack); sym;
383 sym = setNextItem(itmpStack)) {
384 if (sym->liveTo > fsym->liveFrom )
392 /*-----------------------------------------------------------------*/
393 /* isFree - will return 1 if the a free spil location is found */
394 /*-----------------------------------------------------------------*/
395 static DEFSETFUNC(isFree)
398 V_ARG(symbol **,sloc);
399 V_ARG(symbol *,fsym);
401 /* if already found */
405 /* if it is free && and the itmp assigned to
406 this does not have any overlapping live ranges
407 with the one currently being assigned and
408 the size can be accomodated */
410 noOverLap(sym->usl.itmpStack,fsym) &&
411 getSize(sym->type) >= getSize(fsym->type)) {
419 /*-----------------------------------------------------------------*/
420 /* spillLRWithPtrReg :- will spil those live ranges which use PTR */
421 /*-----------------------------------------------------------------*/
422 static void spillLRWithPtrReg (symbol *forSym)
428 if (!_G.regAssigned ||
429 bitVectIsZero(_G.regAssigned))
432 X = avr_regWithIdx(X_IDX);
433 Z = avr_regWithIdx(Z_IDX);
435 /* for all live ranges */
436 for (lrsym = hTabFirstItem(liveRanges,&k) ; lrsym ;
437 lrsym = hTabNextItem(liveRanges,&k) ) {
440 /* if no registers assigned to it or
442 /* if it does not overlap with this then
443 not need to spill it */
445 if (lrsym->isspilt || !lrsym->nRegs ||
446 (lrsym->liveTo < forSym->liveFrom))
449 /* go thru the registers : if it is either
450 r0 or r1 then spil it */
451 for (j = 0 ; j < lrsym->nRegs ; j++ )
452 if (lrsym->regs[j] == X || lrsym->regs[j] == Z ) {
460 /*-----------------------------------------------------------------*/
461 /* createStackSpil - create a location on the stack to spil */
462 /*-----------------------------------------------------------------*/
463 static symbol *createStackSpil (symbol *sym)
466 int useXstack, model, noOverlay;
471 /* first go try and find a free one that is already
472 existing on the stack */
473 if (applyToSet(_G.stackSpil,isFree,&sloc, sym)) {
474 /* found a free one : just update & return */
475 sym->usl.spillLoc = sloc;
478 addSetHead(&sloc->usl.itmpStack,sym);
482 /* could not then have to create one , this is the hard part
483 we need to allocate this on the stack : this is really a
484 hack!! but cannot think of anything better at this time */
486 if (sprintf(slocBuffer,"sloc%d",_G.slocNum++) >= sizeof(slocBuffer))
488 fprintf(stderr, "***Internal error: slocBuffer overflowed: %s:%d\n",
493 sloc = newiTemp(slocBuffer);
495 /* set the type to the spilling symbol */
496 sloc->type = copyLinkChain(sym->type);
497 sloc->etype = getSpec(sloc->type);
498 SPEC_SCLS(sloc->etype) = S_AUTO ;
499 SPEC_EXTR(sloc->etype) = 0;
501 /* we don't allow it to be allocated`
502 onto the external stack since : so we
503 temporarily turn it off ; we also
504 turn off memory model to prevent
505 the spil from going to the external storage
506 and turn off overlaying
509 useXstack = options.useXstack;
510 model = options.model;
511 noOverlay = options.noOverlay;
512 stackAuto = options.stackAuto;
513 options.noOverlay = 1;
514 options.model = options.useXstack = 0;
518 options.useXstack = useXstack;
519 options.model = model;
520 options.noOverlay = noOverlay;
521 options.stackAuto = stackAuto;
522 sloc->isref = 1; /* to prevent compiler warning */
524 /* if it is on the stack then update the stack */
525 if (IN_STACK(sloc->etype)) {
526 currFunc->stack += getSize(sloc->type);
527 _G.stackExtend += getSize(sloc->type);
529 _G.dataExtend += getSize(sloc->type);
531 /* add it to the _G.stackSpil set */
532 addSetHead(&_G.stackSpil,sloc);
533 sym->usl.spillLoc = sloc;
536 /* add it to the set of itempStack set
537 of the spill location */
538 addSetHead(&sloc->usl.itmpStack,sym);
542 /*-----------------------------------------------------------------*/
543 /* isSpiltOnStack - returns true if the spil location is on stack */
544 /*-----------------------------------------------------------------*/
545 static bool isSpiltOnStack (symbol *sym)
556 if (!sym->usl.spillLoc)
559 etype = getSpec(sym->usl.spillLoc->type);
566 /*-----------------------------------------------------------------*/
567 /* spillThis - spils a specific operand */
568 /*-----------------------------------------------------------------*/
569 static void spillThis (symbol *sym)
572 /* if this is rematerializable or has a spillLocation
573 we are okay, else we need to create a spillLocation
575 if (!(sym->remat || sym->usl.spillLoc))
576 createStackSpil (sym);
579 /* mark it has spilt & put it in the spilt set */
581 _G.spiltSet = bitVectSetBit(_G.spiltSet,sym->key);
583 bitVectUnSetBit(_G.regAssigned,sym->key);
585 for (i = 0 ; i < sym->nRegs ; i++)
588 freeReg(sym->regs[i]);
592 if (sym->usl.spillLoc && !sym->remat)
593 sym->usl.spillLoc->allocreq = 1;
597 /*-----------------------------------------------------------------*/
598 /* selectSpil - select a iTemp to spil : rather a simple procedure */
599 /*-----------------------------------------------------------------*/
600 static symbol *selectSpil (iCode *ic, eBBlock *ebp, symbol *forSym)
602 bitVect *lrcs= NULL ;
606 /* get the spillable live ranges */
607 lrcs = computeSpillable (ic);
609 /* get all live ranges that are rematerizable */
610 if ((selectS = liveRangesWith(lrcs,rematable,ebp,ic))) {
612 /* return the least used of these */
613 return leastUsedLR(selectS);
616 /* if the symbol is local to the block then */
617 if (forSym->liveTo < ebp->lSeq ) {
619 /* check if there are any live ranges allocated
620 to registers that are not used in this block */
622 (selectS = liveRangesWith(lrcs,notUsedInBlock,ebp,ic))) {
623 sym = leastUsedLR(selectS);
624 /* if this is not rematerializable */
632 /* check if there are any live ranges that not
633 used in the remainder of the block */
635 (selectS = liveRangesWith(lrcs,notUsedInRemaining,ebp,ic))) {
636 sym = leastUsedLR (selectS);
645 /* find live ranges with spillocation && not used as pointers */
646 if ((selectS = liveRangesWith(lrcs,hasSpilLocnoUptr,ebp,ic))) {
648 sym = leastUsedLR(selectS);
649 /* mark this as allocation required */
650 sym->usl.spillLoc->allocreq = 1;
654 /* find live ranges with spillocation */
655 if ((selectS = liveRangesWith(lrcs,hasSpilLoc,ebp,ic))) {
657 sym = leastUsedLR(selectS);
658 sym->usl.spillLoc->allocreq = 1;
662 /* couldn't find then we need to create a spil
663 location on the stack , for which one? the least
665 if ((selectS = liveRangesWith(lrcs,noSpilLoc,ebp,ic))) {
667 /* return a created spil location */
668 sym = createStackSpil(leastUsedLR(selectS));
669 sym->usl.spillLoc->allocreq = 1;
673 /* this is an extreme situation we will spill
674 this one : happens very rarely but it does happen */
675 spillThis ( forSym );
680 /*-----------------------------------------------------------------*/
681 /* spilSomething - spil some variable & mark registers as free */
682 /*-----------------------------------------------------------------*/
683 static bool spilSomething (iCode *ic, eBBlock *ebp, symbol *forSym)
688 /* get something we can spil */
689 ssym = selectSpil(ic,ebp,forSym);
691 /* mark it as spilt */
693 _G.spiltSet = bitVectSetBit(_G.spiltSet,ssym->key);
695 /* mark it as not register assigned &
696 take it away from the set */
697 bitVectUnSetBit(_G.regAssigned,ssym->key);
699 /* mark the registers as free */
700 for (i = 0 ; i < ssym->nRegs ;i++ )
702 freeReg(ssym->regs[i]);
704 /* if this was a block level spil then insert push & pop
705 at the start & end of block respectively */
706 if (ssym->blockSpil) {
707 iCode *nic = newiCode(IPUSH,operandFromSymbol(ssym),NULL);
708 /* add push to the start of the block */
709 addiCodeToeBBlock(ebp,nic,( ebp->sch->op == LABEL ?
710 ebp->sch->next : ebp->sch));
711 nic = newiCode(IPOP,operandFromSymbol(ssym),NULL);
712 /* add pop to the end of the block */
713 addiCodeToeBBlock(ebp,nic,NULL);
716 /* if spilt because not used in the remainder of the
717 block then add a push before this instruction and
718 a pop at the end of the block */
719 if (ssym->remainSpil) {
721 iCode *nic = newiCode(IPUSH,operandFromSymbol(ssym),NULL);
722 /* add push just before this instruction */
723 addiCodeToeBBlock(ebp,nic,ic);
725 nic = newiCode(IPOP,operandFromSymbol(ssym),NULL);
726 /* add pop to the end of the block */
727 addiCodeToeBBlock(ebp,nic,NULL);
736 /*-----------------------------------------------------------------*/
737 /* getRegPtr - will try for PTR if not a GPR type if not spil */
738 /*-----------------------------------------------------------------*/
739 static regs *getRegPtr (iCode *ic, eBBlock *ebp, symbol *sym)
744 /* try for a ptr type */
745 if ((reg = allocReg(REG_PTR)))
748 /* try for gpr type */
749 if ((reg = allocReg(REG_GPR)))
752 /* we have to spil */
753 if (!spilSomething (ic,ebp,sym))
756 /* this looks like an infinite loop but
757 in really selectSpil will abort */
761 /*-----------------------------------------------------------------*/
762 /* getRegGpr - will try for GPR if not spil */
763 /*-----------------------------------------------------------------*/
764 static regs *getRegGpr (iCode *ic, eBBlock *ebp,symbol *sym)
769 /* try for gpr type */
770 if ((reg = allocReg(REG_GPR)))
774 if ((reg = allocReg(REG_PTR)))
777 /* we have to spil */
778 if (!spilSomething (ic,ebp,sym))
781 /* this looks like an infinite loop but
782 in reality selectSpil will abort */
786 /*-----------------------------------------------------------------*/
787 /* symHasReg - symbol has a given register */
788 /*-----------------------------------------------------------------*/
789 static bool symHasReg(symbol *sym,regs *reg)
793 for ( i = 0 ; i < sym->nRegs ; i++)
794 if (sym->regs[i] == reg)
800 /*-----------------------------------------------------------------*/
801 /* deassignLRs - check the live to and if they have registers & are*/
802 /* not spilt then free up the registers */
803 /*-----------------------------------------------------------------*/
804 static void deassignLRs (iCode *ic, eBBlock *ebp)
810 for (sym = hTabFirstItem(liveRanges,&k); sym;
811 sym = hTabNextItem(liveRanges,&k)) {
814 /* if it does not end here */
815 if (sym->liveTo > ic->seq )
818 /* if it was spilt on stack then we can
819 mark the stack spil location as free */
821 if (sym->stackSpil) {
822 sym->usl.spillLoc->isFree = 1;
828 if (!bitVectBitValue(_G.regAssigned,sym->key))
831 /* special case check if this is an IFX &
832 the privious one was a pop and the
833 previous one was not spilt then keep track
835 if (ic->op == IFX && ic->prev &&
836 ic->prev->op == IPOP &&
837 !ic->prev->parmPush &&
838 !OP_SYMBOL(IC_LEFT(ic->prev))->isspilt)
839 psym = OP_SYMBOL(IC_LEFT(ic->prev));
844 bitVectUnSetBit(_G.regAssigned,sym->key);
846 /* if the result of this one needs registers
847 and does not have it then assign it right
850 ! (SKIP_IC2(ic) || /* not a special icode */
851 ic->op == JUMPTABLE ||
857 (result = OP_SYMBOL(IC_RESULT(ic))) && /* has a result */
858 result->liveTo > ic->seq && /* and will live beyond this */
859 result->liveTo <= ebp->lSeq && /* does not go beyond this block */
860 result->regType == sym->regType && /* same register types */
861 result->nRegs && /* which needs registers */
862 ! result->isspilt && /* and does not already have them */
864 ! bitVectBitValue(_G.regAssigned,result->key) &&
865 /* the number of free regs + number of regs in this LR
866 can accomodate the what result Needs */
867 ((nfreeRegsType(result->regType) +
868 sym->nRegs) >= result->nRegs)
871 for (i = 0 ; i < max(sym->nRegs,result->nRegs) ; i++)
873 result->regs[i] = sym->regs[i] ;
875 result->regs[i] = getRegGpr (ic,ebp,result);
877 _G.regAssigned = bitVectSetBit(_G.regAssigned,result->key);
881 /* free the remaining */
882 for (; i < sym->nRegs ; i++) {
884 if (!symHasReg(psym,sym->regs[i]))
885 freeReg(sym->regs[i]);
887 freeReg(sym->regs[i]);
894 /*-----------------------------------------------------------------*/
895 /* reassignLR - reassign this to registers */
896 /*-----------------------------------------------------------------*/
897 static void reassignLR (operand *op)
899 symbol *sym = OP_SYMBOL(op);
902 /* not spilt any more */
903 sym->isspilt = sym->blockSpil = sym->remainSpil = 0;
904 bitVectUnSetBit(_G.spiltSet,sym->key);
906 _G.regAssigned = bitVectSetBit(_G.regAssigned,sym->key);
910 for (i=0;i<sym->nRegs;i++)
911 sym->regs[i]->isFree = 0;
914 /*-----------------------------------------------------------------*/
915 /* willCauseSpill - determines if allocating will cause a spill */
916 /*-----------------------------------------------------------------*/
917 static int willCauseSpill ( int nr, int rt)
919 /* first check if there are any avlb registers
920 of te type required */
922 /* special case for pointer type
923 if pointer type not avlb then
924 check for type gpr */
925 if (nFreeRegs(rt) >= nr)
927 if (nFreeRegs(REG_GPR) >= nr)
931 if (nFreeRegs(rt) >= nr)
934 if (nFreeRegs(REG_PTR) +
935 nFreeRegs(REG_GPR) >= nr)
940 /* it will cause a spil */
944 /*-----------------------------------------------------------------*/
945 /* positionRegs - the allocator can allocate same registers to res-*/
946 /* ult and operand, if this happens make sure they are in the same */
947 /* position as the operand otherwise chaos results */
948 /*-----------------------------------------------------------------*/
949 static void positionRegs (symbol *result, symbol *opsym, int lineno)
951 int count = min(result->nRegs,opsym->nRegs);
952 int i , j = 0, shared = 0;
954 /* if the result has been spilt then cannot share */
959 /* first make sure that they actually share */
960 for ( i = 0 ; i < count; i++ ) {
961 for (j = 0 ; j < count ; j++ ) {
962 if (result->regs[i] == opsym->regs[j] && i !=j) {
970 regs *tmp = result->regs[i];
971 result->regs[i] = result->regs[j];
972 result->regs[j] = tmp;
977 /*-----------------------------------------------------------------*/
978 /* serialRegAssign - serially allocate registers to the variables */
979 /*-----------------------------------------------------------------*/
980 static void serialRegAssign (eBBlock **ebbs, int count)
985 for (i = 0; i < count ; i++ ) {
989 if (ebbs[i]->noPath &&
990 (ebbs[i]->entryLabel != entryLabel &&
991 ebbs[i]->entryLabel != returnLabel ))
994 /* of all instructions do */
995 for (ic = ebbs[i]->sch ; ic ; ic = ic->next) {
997 /* if this is an ipop that means some live
998 range will have to be assigned again */
1000 reassignLR (IC_LEFT(ic));
1002 /* if result is present && is a true symbol */
1003 if (IC_RESULT(ic) && ic->op != IFX &&
1004 IS_TRUE_SYMOP(IC_RESULT(ic)))
1005 OP_SYMBOL(IC_RESULT(ic))->allocreq = 1;
1007 /* take away registers from live
1008 ranges that end at this instruction */
1009 deassignLRs (ic, ebbs[i]) ;
1011 /* some don't need registers */
1013 ic->op == JUMPTABLE ||
1017 (IC_RESULT(ic) &&POINTER_SET(ic)) )
1020 /* now we need to allocate registers
1021 only for the result */
1022 if (IC_RESULT(ic)) {
1023 symbol *sym = OP_SYMBOL(IC_RESULT(ic));
1029 /* if it does not need or is spilt
1030 or is already assigned to registers
1031 or will not live beyond this instructions */
1034 bitVectBitValue(_G.regAssigned,sym->key) ||
1035 sym->liveTo <= ic->seq)
1038 /* if some liverange has been spilt at the block level
1039 and this one live beyond this block then spil this
1041 if (_G.blockSpil && sym->liveTo > ebbs[i]->lSeq) {
1045 /* if trying to allocate this will cause
1046 a spill and there is nothing to spill
1047 or this one is rematerializable then
1049 willCS = willCauseSpill(sym->nRegs,sym->regType);
1050 spillable = computeSpillable(ic);
1052 (willCS && bitVectIsZero(spillable) ) ) {
1059 /* if it has a spillocation & is used less than
1060 all other live ranges then spill this */
1061 if ( willCS && sym->usl.spillLoc ) {
1064 leastUsedLR(liveRangesWith (spillable ,
1069 leastUsed->used > sym->used) {
1075 /* if we need ptr regs for the right side
1077 if (POINTER_GET(ic) &&
1078 getSize(OP_SYMBOL(IC_LEFT(ic))->type) <= 2)
1083 /* else we assign registers to it */
1084 _G.regAssigned = bitVectSetBit(_G.regAssigned,sym->key);
1086 for (j = 0 ; j < sym->nRegs ;j++ ) {
1087 if (sym->regType == REG_PTR)
1088 sym->regs[j] = getRegPtr(ic,ebbs[i],sym);
1090 sym->regs[j] = getRegGpr(ic,ebbs[i],sym);
1092 /* if the allocation falied which means
1093 this was spilt then break */
1097 /* if it shares registers with operands make sure
1098 that they are in the same position */
1099 if (IC_LEFT(ic) && IS_SYMOP(IC_LEFT(ic)) &&
1100 OP_SYMBOL(IC_LEFT(ic))->nRegs && ic->op != '=')
1101 positionRegs(OP_SYMBOL(IC_RESULT(ic)),
1102 OP_SYMBOL(IC_LEFT(ic)),ic->lineno);
1103 /* do the same for the right operand */
1104 if (IC_RIGHT(ic) && IS_SYMOP(IC_RIGHT(ic)) &&
1105 OP_SYMBOL(IC_RIGHT(ic))->nRegs && ic->op != '=')
1106 positionRegs(OP_SYMBOL(IC_RESULT(ic)),
1107 OP_SYMBOL(IC_RIGHT(ic)),ic->lineno);
1119 /*-----------------------------------------------------------------*/
1120 /* rUmaskForOp :- returns register mask for an operand */
1121 /*-----------------------------------------------------------------*/
1122 static bitVect *rUmaskForOp (operand *op)
1128 /* only temporaries are assigned registers */
1132 sym = OP_SYMBOL(op);
1134 /* if spilt or no registers assigned to it
1136 if (sym->isspilt || !sym->nRegs)
1139 rumask = newBitVect(avr_nRegs);
1141 for (j = 0; j < sym->nRegs; j++) {
1142 rumask = bitVectSetBit(rumask,
1143 sym->regs[j]->rIdx);
1149 /*-----------------------------------------------------------------*/
1150 /* regsUsedIniCode :- returns bit vector of registers used in iCode*/
1151 /*-----------------------------------------------------------------*/
1152 static bitVect *regsUsedIniCode (iCode *ic)
1154 bitVect *rmask = newBitVect(avr_nRegs);
1156 /* do the special cases first */
1157 if (ic->op == IFX ) {
1158 rmask = bitVectUnion(rmask,
1159 rUmaskForOp(IC_COND(ic)));
1163 /* for the jumptable */
1164 if (ic->op == JUMPTABLE) {
1165 rmask = bitVectUnion(rmask,
1166 rUmaskForOp(IC_JTCOND(ic)));
1171 /* of all other cases */
1173 rmask = bitVectUnion(rmask,
1174 rUmaskForOp(IC_LEFT(ic)));
1178 rmask = bitVectUnion(rmask,
1179 rUmaskForOp(IC_RIGHT(ic)));
1182 rmask = bitVectUnion(rmask,
1183 rUmaskForOp(IC_RESULT(ic)));
1189 /*-----------------------------------------------------------------*/
1190 /* createRegMask - for each instruction will determine the regsUsed*/
1191 /*-----------------------------------------------------------------*/
1192 static void createRegMask (eBBlock **ebbs, int count)
1196 /* for all blocks */
1197 for (i = 0; i < count ; i++ ) {
1200 if ( ebbs[i]->noPath &&
1201 ( ebbs[i]->entryLabel != entryLabel &&
1202 ebbs[i]->entryLabel != returnLabel ))
1205 /* for all instructions */
1206 for ( ic = ebbs[i]->sch ; ic ; ic = ic->next ) {
1210 if (SKIP_IC2(ic) || !ic->rlive)
1213 /* first mark the registers used in this
1215 ic->rUsed = regsUsedIniCode(ic);
1216 _G.funcrUsed = bitVectUnion(_G.funcrUsed,ic->rUsed);
1218 /* now create the register mask for those
1219 registers that are in use : this is a
1220 super set of ic->rUsed */
1221 ic->rMask = newBitVect(avr_nRegs+1);
1223 /* for all live Ranges alive at this point */
1224 for (j = 1; j < ic->rlive->size; j++ ) {
1228 /* if not alive then continue */
1229 if (!bitVectBitValue(ic->rlive,j))
1232 /* find the live range we are interested in */
1233 if (!(sym = hTabItemWithKey(liveRanges,j))) {
1234 werror (E_INTERNAL_ERROR,__FILE__,__LINE__,
1235 "createRegMask cannot find live range");
1239 /* if no register assigned to it */
1240 if (!sym->nRegs || sym->isspilt)
1243 /* for all the registers allocated to it */
1244 for (k = 0 ; k < sym->nRegs ;k++)
1247 bitVectSetBit(ic->rMask,sym->regs[k]->rIdx);
1253 /*-----------------------------------------------------------------*/
1254 /* rematStr - returns the rematerialized string for a remat var */
1255 /*-----------------------------------------------------------------*/
1256 static char *rematStr (symbol *sym)
1259 iCode *ic = sym->rematiCode;
1263 /* if plus or minus print the right hand side */
1264 if (ic->op == '+' || ic->op == '-') {
1265 sprintf(s,"0x%04x %c ",(int) operandLitValue(IC_RIGHT(ic)),
1268 ic = OP_SYMBOL(IC_LEFT(ic))->rematiCode;
1272 /* we reached the end */
1273 sprintf(s,"%s",OP_SYMBOL(IC_LEFT(ic))->rname);
1280 /*-----------------------------------------------------------------*/
1281 /* regTypeNum - computes the type & number of registers required */
1282 /*-----------------------------------------------------------------*/
1283 static void regTypeNum ()
1289 /* for each live range do */
1290 for ( sym = hTabFirstItem(liveRanges,&k); sym ;
1291 sym = hTabNextItem(liveRanges,&k)) {
1293 /* if used zero times then no registers needed */
1294 if ((sym->liveTo - sym->liveFrom) == 0)
1298 /* if the live range is a temporary */
1301 /* if the type is marked as a conditional */
1302 if (sym->regType == REG_CND)
1305 /* if used in return only then we don't
1307 if (sym->ruonly || sym->accuse) {
1308 if (IS_AGGREGATE(sym->type) || sym->isptr)
1309 sym->type = aggrToPtr(sym->type,FALSE);
1313 /* if the symbol has only one definition &
1314 that definition is a get_pointer and the
1315 pointer we are getting is rematerializable and
1318 if (bitVectnBitsOn(sym->defs) == 1 &&
1319 (ic = hTabItemWithKey(iCodehTab,
1320 bitVectFirstBit(sym->defs))) &&
1322 !IS_BITVAR(sym->etype)) {
1325 /* if remat in data space */
1326 /* if (OP_SYMBOL(IC_LEFT(ic))->remat && */
1327 /* DCL_TYPE(aggrToPtr(sym->type,FALSE)) == POINTER) { */
1329 /* create a psuedo symbol & force a spil */
1330 /* symbol *psym = newSymbol(rematStr(OP_SYMBOL(IC_LEFT(ic))),1); */
1331 /* psym->type = sym->type; */
1332 /* psym->etype = sym->etype; */
1333 /* strcpy(psym->rname,psym->name); */
1334 /* sym->isspilt = 1; */
1335 /* sym->usl.spillLoc = psym; */
1339 /* if in data space or idata space then try to
1340 allocate pointer register */
1344 /* if not then we require registers */
1345 sym->nRegs = ((IS_AGGREGATE(sym->type) || sym->isptr ) ?
1346 getSize(sym->type = aggrToPtr(sym->type,FALSE)) :
1347 getSize(sym->type));
1349 if (sym->nRegs > 4) {
1350 fprintf(stderr,"allocated more than 4 or 0 registers for type ");
1351 printTypeChain(sym->type,stderr);fprintf(stderr,"\n");
1354 /* determine the type of register required */
1355 if (sym->nRegs == 1 &&
1356 IS_PTR(sym->type) &&
1358 sym->regType = REG_PTR ;
1360 sym->regType = REG_GPR ;
1363 /* for the first run we don't provide */
1364 /* registers for true symbols we will */
1365 /* see how things go */
1371 /*-----------------------------------------------------------------*/
1372 /* freeAllRegs - mark all registers as free */
1373 /*-----------------------------------------------------------------*/
1374 static void freeAllRegs()
1378 for (i=0;i< avr_nRegs;i++ )
1379 regsAVR[i].isFree = 1;
1382 /*-----------------------------------------------------------------*/
1383 /* deallocStackSpil - this will set the stack pointer back */
1384 /*-----------------------------------------------------------------*/
1385 static DEFSETFUNC(deallocStackSpil)
1393 /*-----------------------------------------------------------------*/
1394 /* farSpacePackable - returns the packable icode for far variables */
1395 /*-----------------------------------------------------------------*/
1396 static iCode *farSpacePackable (iCode *ic)
1400 /* go thru till we find a definition for the
1401 symbol on the right */
1402 for ( dic = ic->prev ; dic ; dic = dic->prev) {
1404 /* if the definition is a call then no */
1405 if ((dic->op == CALL || dic->op == PCALL) &&
1406 IC_RESULT(dic)->key == IC_RIGHT(ic)->key) {
1410 /* if shift by unknown amount then not */
1411 if ((dic->op == LEFT_OP || dic->op == RIGHT_OP) &&
1412 IC_RESULT(dic)->key == IC_RIGHT(ic)->key)
1415 /* if pointer get and size > 1 */
1416 if (POINTER_GET(dic) &&
1417 getSize(aggrToPtr(operandType(IC_LEFT(dic)),FALSE)) > 1)
1420 if (POINTER_SET(dic) &&
1421 getSize(aggrToPtr(operandType(IC_RESULT(dic)),FALSE)) > 1)
1424 /* if any three is a true symbol in far space */
1425 if (IC_RESULT(dic) &&
1426 IS_TRUE_SYMOP(IC_RESULT(dic)) &&
1427 isOperandInFarSpace(IC_RESULT(dic)))
1430 if (IC_RIGHT(dic) &&
1431 IS_TRUE_SYMOP(IC_RIGHT(dic)) &&
1432 isOperandInFarSpace(IC_RIGHT(dic)) &&
1433 !isOperandEqual(IC_RIGHT(dic),IC_RESULT(ic)))
1437 IS_TRUE_SYMOP(IC_LEFT(dic)) &&
1438 isOperandInFarSpace(IC_LEFT(dic)) &&
1439 !isOperandEqual(IC_LEFT(dic),IC_RESULT(ic)))
1442 if (isOperandEqual(IC_RIGHT(ic),IC_RESULT(dic))) {
1443 if ( (dic->op == LEFT_OP ||
1444 dic->op == RIGHT_OP ||
1446 IS_OP_LITERAL(IC_RIGHT(dic)))
1456 /*-----------------------------------------------------------------*/
1457 /* packRegsForAssign - register reduction for assignment */
1458 /*-----------------------------------------------------------------*/
1459 static int packRegsForAssign (iCode *ic,eBBlock *ebp)
1463 if (!IS_ITEMP(IC_RIGHT(ic)) ||
1464 OP_SYMBOL(IC_RIGHT(ic))->isind ||
1465 OP_LIVETO(IC_RIGHT(ic)) > ic->seq) {
1469 /* if the true symbol is defined in far space or on stack
1470 then we should not since this will increase register pressure */
1471 if (isOperandInFarSpace(IC_RESULT(ic))) {
1472 if ((dic = farSpacePackable(ic)))
1478 /* find the definition of iTempNN scanning backwards if we find a
1479 a use of the true symbol in before we find the definition then
1481 for ( dic = ic->prev ; dic ; dic = dic->prev) {
1483 /* if there is a function call and this is
1484 a parameter & not my parameter then don't pack it */
1485 if ( (dic->op == CALL || dic->op == PCALL) &&
1486 (OP_SYMBOL(IC_RESULT(ic))->_isparm &&
1487 !OP_SYMBOL(IC_RESULT(ic))->ismyparm)) {
1495 if (IS_TRUE_SYMOP(IC_RESULT(dic)) &&
1496 IS_OP_VOLATILE(IC_RESULT(dic))) {
1501 if (IS_SYMOP(IC_RESULT(dic)) &&
1502 IC_RESULT(dic)->key == IC_RIGHT(ic)->key) {
1503 if (POINTER_SET(dic))
1509 if (IS_SYMOP(IC_RIGHT(dic)) &&
1510 (IC_RIGHT(dic)->key == IC_RESULT(ic)->key ||
1511 IC_RIGHT(dic)->key == IC_RIGHT(ic)->key)) {
1516 if (IS_SYMOP(IC_LEFT(dic)) &&
1517 (IC_LEFT(dic)->key == IC_RESULT(ic)->key ||
1518 IC_LEFT(dic)->key == IC_RIGHT(ic)->key)) {
1523 if (POINTER_SET(dic) &&
1524 IC_RESULT(dic)->key == IC_RESULT(ic)->key ) {
1531 return 0 ; /* did not find */
1533 /* if the result is on stack or iaccess then it must be
1534 the same atleast one of the operands */
1535 if (OP_SYMBOL(IC_RESULT(ic))->onStack ||
1536 OP_SYMBOL(IC_RESULT(ic))->iaccess ) {
1538 /* the operation has only one symbol
1539 operator then we can pack */
1540 if ((IC_LEFT(dic) && !IS_SYMOP(IC_LEFT(dic))) ||
1541 (IC_RIGHT(dic) && !IS_SYMOP(IC_RIGHT(dic))))
1544 if (!((IC_LEFT(dic) &&
1545 IC_RESULT(ic)->key == IC_LEFT(dic)->key) ||
1547 IC_RESULT(ic)->key == IC_RIGHT(dic)->key)))
1551 /* found the definition */
1552 /* replace the result with the result of */
1553 /* this assignment and remove this assignment */
1554 IC_RESULT(dic) = IC_RESULT(ic) ;
1556 if (IS_ITEMP(IC_RESULT(dic)) && OP_SYMBOL(IC_RESULT(dic))->liveFrom > dic->seq) {
1557 OP_SYMBOL(IC_RESULT(dic))->liveFrom = dic->seq;
1559 /* delete from liverange table also
1560 delete from all the points inbetween and the new
1562 for ( sic = dic; sic != ic ; sic = sic->next ) {
1563 bitVectUnSetBit(sic->rlive,IC_RESULT(ic)->key);
1564 if (IS_ITEMP(IC_RESULT(dic)))
1565 bitVectSetBit(sic->rlive,IC_RESULT(dic)->key);
1568 remiCodeFromeBBlock(ebp,ic);
1569 hTabDeleteItem (&iCodehTab,ic->key,ic,DELETE_ITEM,NULL);
1574 /*-----------------------------------------------------------------*/
1575 /* findAssignToSym : scanning backwards looks for first assig found*/
1576 /*-----------------------------------------------------------------*/
1577 static iCode *findAssignToSym (operand *op,iCode *ic)
1581 for (dic = ic->prev ; dic ; dic = dic->prev) {
1583 /* if definition by assignment */
1584 if (dic->op == '=' &&
1585 !POINTER_SET(dic) &&
1586 IC_RESULT(dic)->key == op->key
1587 /* && IS_TRUE_SYMOP(IC_RIGHT(dic)) */
1590 /* we are interested only if defined in far space */
1591 /* or in stack space in case of + & - */
1593 /* if assigned to a non-symbol then return
1595 if (!IS_SYMOP(IC_RIGHT(dic)))
1598 /* if the symbol is in far space then
1600 if (isOperandInFarSpace(IC_RIGHT(dic)))
1603 /* for + & - operations make sure that
1604 if it is on the stack it is the same
1605 as one of the three operands */
1606 if ((ic->op == '+' || ic->op == '-') &&
1607 OP_SYMBOL(IC_RIGHT(dic))->onStack) {
1609 if ( IC_RESULT(ic)->key != IC_RIGHT(dic)->key &&
1610 IC_LEFT(ic)->key != IC_RIGHT(dic)->key &&
1611 IC_RIGHT(ic)->key != IC_RIGHT(dic)->key)
1619 /* if we find an usage then we cannot delete it */
1620 if (IC_LEFT(dic) && IC_LEFT(dic)->key == op->key)
1623 if (IC_RIGHT(dic) && IC_RIGHT(dic)->key == op->key)
1626 if (POINTER_SET(dic) && IC_RESULT(dic)->key == op->key)
1630 /* now make sure that the right side of dic
1631 is not defined between ic & dic */
1633 iCode *sic = dic->next ;
1635 for (; sic != ic ; sic = sic->next)
1636 if (IC_RESULT(sic) &&
1637 IC_RESULT(sic)->key == IC_RIGHT(dic)->key)
1646 /*-----------------------------------------------------------------*/
1647 /* packRegsForSupport :- reduce some registers for support calls */
1648 /*-----------------------------------------------------------------*/
1649 static int packRegsForSupport (iCode *ic, eBBlock *ebp)
1652 /* for the left & right operand :- look to see if the
1653 left was assigned a true symbol in far space in that
1654 case replace them */
1655 if (IS_ITEMP(IC_LEFT(ic)) &&
1656 OP_SYMBOL(IC_LEFT(ic))->liveTo <= ic->seq) {
1657 iCode *dic = findAssignToSym(IC_LEFT(ic),ic);
1663 /* found it we need to remove it from the
1665 for ( sic = dic; sic != ic ; sic = sic->next )
1666 bitVectUnSetBit(sic->rlive,IC_LEFT(ic)->key);
1668 IC_LEFT(ic)->operand.symOperand =
1669 IC_RIGHT(dic)->operand.symOperand;
1670 IC_LEFT(ic)->key = IC_RIGHT(dic)->operand.symOperand->key;
1671 remiCodeFromeBBlock(ebp,dic);
1672 hTabDeleteItem (&iCodehTab,dic->key,dic,DELETE_ITEM,NULL);
1676 /* do the same for the right operand */
1679 IS_ITEMP(IC_RIGHT(ic)) &&
1680 OP_SYMBOL(IC_RIGHT(ic))->liveTo <= ic->seq) {
1681 iCode *dic = findAssignToSym(IC_RIGHT(ic),ic);
1687 /* if this is a subtraction & the result
1688 is a true symbol in far space then don't pack */
1689 if (ic->op == '-' && IS_TRUE_SYMOP(IC_RESULT(dic))) {
1690 link *etype =getSpec(operandType(IC_RESULT(dic)));
1691 if (IN_FARSPACE(SPEC_OCLS(etype)))
1694 /* found it we need to remove it from the
1696 for ( sic = dic; sic != ic ; sic = sic->next )
1697 bitVectUnSetBit(sic->rlive,IC_RIGHT(ic)->key);
1699 IC_RIGHT(ic)->operand.symOperand =
1700 IC_RIGHT(dic)->operand.symOperand;
1701 IC_RIGHT(ic)->key = IC_RIGHT(dic)->operand.symOperand->key;
1703 remiCodeFromeBBlock(ebp,dic);
1704 hTabDeleteItem (&iCodehTab,dic->key,dic,DELETE_ITEM,NULL);
1711 #define IS_OP_RUONLY(x) (x && IS_SYMOP(x) && OP_SYMBOL(x)->ruonly)
1714 /*-----------------------------------------------------------------*/
1715 /* packRegsForOneuse : - will reduce some registers for single Use */
1716 /*-----------------------------------------------------------------*/
1717 static iCode *packRegsForOneuse (iCode *ic, operand *op , eBBlock *ebp)
1722 /* if returning a literal then do nothing */
1726 /* only upto 2 bytes since we cannot predict
1727 the usage of b, & acc */
1728 if (getSize(operandType(op)) > (fReturnSize - 2) &&
1733 /* this routine will mark the a symbol as used in one
1734 instruction use only && if the defintion is local
1735 (ie. within the basic block) && has only one definition &&
1736 that definiion is either a return value from a
1737 function or does not contain any variables in
1739 uses = bitVectCopy(OP_USES(op));
1740 bitVectUnSetBit(uses,ic->key); /* take away this iCode */
1741 if (!bitVectIsZero(uses)) /* has other uses */
1744 /* if it has only one defintion */
1745 if (bitVectnBitsOn(OP_DEFS(op)) > 1)
1746 return NULL ; /* has more than one definition */
1748 /* get the that definition */
1750 hTabItemWithKey(iCodehTab,
1751 bitVectFirstBit(OP_DEFS(op)))))
1754 /* found the definition now check if it is local */
1755 if (dic->seq < ebp->fSeq ||
1756 dic->seq > ebp->lSeq)
1757 return NULL ; /* non-local */
1759 /* now check if it is the return from
1761 if (dic->op == CALL || dic->op == PCALL ) {
1762 if (ic->op != SEND && ic->op != RETURN) {
1763 /* OP_SYMBOL(op)->ruonly = 1; */
1770 /* otherwise check that the definition does
1771 not contain any symbols in far space */
1772 if (isOperandInFarSpace(IC_LEFT(dic)) ||
1773 isOperandInFarSpace(IC_RIGHT(dic)) ||
1774 IS_OP_RUONLY(IC_LEFT(ic)) ||
1775 IS_OP_RUONLY(IC_RIGHT(ic)) ) {
1779 /* if pointer set then make sure the pointer
1781 if (POINTER_SET(dic) &&
1782 !IS_DATA_PTR(aggrToPtr(operandType(IC_RESULT(dic)),FALSE)))
1785 if (POINTER_GET(dic) &&
1786 !IS_DATA_PTR(aggrToPtr(operandType(IC_LEFT(dic)),FALSE)))
1791 /* also make sure the intervenening instructions
1792 don't have any thing in far space */
1793 for (dic = dic->next ; dic && dic != ic ; dic = dic->next) {
1795 /* if there is an intervening function call then no */
1796 if (dic->op == CALL || dic->op == PCALL)
1798 /* if pointer set then make sure the pointer
1800 if (POINTER_SET(dic) &&
1801 !IS_DATA_PTR(aggrToPtr(operandType(IC_RESULT(dic)),FALSE)))
1804 if (POINTER_GET(dic) &&
1805 !IS_DATA_PTR(aggrToPtr(operandType(IC_LEFT(dic)),FALSE)))
1808 /* if address of & the result is remat the okay */
1809 if (dic->op == ADDRESS_OF &&
1810 OP_SYMBOL(IC_RESULT(dic))->remat)
1813 /* if operand has size of three or more & this
1814 operation is a '*','/' or '%' then 'b' may
1816 if (( dic->op == '%' || dic->op == '/' || dic->op == '*') &&
1817 getSize(operandType(op)) >= 3)
1820 /* if left or right or result is in far space */
1821 if (isOperandInFarSpace(IC_LEFT(dic)) ||
1822 isOperandInFarSpace(IC_RIGHT(dic)) ||
1823 isOperandInFarSpace(IC_RESULT(dic)) ||
1824 IS_OP_RUONLY(IC_LEFT(dic)) ||
1825 IS_OP_RUONLY(IC_RIGHT(dic)) ||
1826 IS_OP_RUONLY(IC_RESULT(dic)) ) {
1831 /* OP_SYMBOL(op)->ruonly = 1; */
1836 /*-----------------------------------------------------------------*/
1837 /* isBitwiseOptimizable - requirements of JEAN LOUIS VERN */
1838 /*-----------------------------------------------------------------*/
1839 static bool isBitwiseOptimizable (iCode *ic)
1841 link *ltype = getSpec(operandType(IC_LEFT(ic)));
1842 link *rtype = getSpec(operandType(IC_RIGHT(ic)));
1844 /* bitwise operations are considered optimizable
1845 under the following conditions (Jean-Louis VERN)
1857 if ( IS_LITERAL(rtype) ||
1858 (IS_BITVAR(ltype) && IN_BITSPACE(SPEC_OCLS(ltype))))
1864 /*-----------------------------------------------------------------*/
1865 /* packRegsForAccUse - pack registers for acc use */
1866 /*-----------------------------------------------------------------*/
1867 static void packRegsForAccUse (iCode *ic)
1871 /* if + or - then it has to be one byte result */
1872 if ((ic->op == '+' || ic->op == '-')
1873 && getSize(operandType(IC_RESULT(ic))) > 1)
1876 /* if shift operation make sure right side is not a literal */
1877 if (ic->op == RIGHT_OP &&
1878 ( isOperandLiteral(IC_RIGHT(ic)) ||
1879 getSize(operandType(IC_RESULT(ic))) > 1))
1882 if (ic->op == LEFT_OP &&
1883 ( isOperandLiteral(IC_RIGHT(ic)) ||
1884 getSize(operandType(IC_RESULT(ic))) > 1))
1887 if (IS_BITWISE_OP(ic) &&
1888 getSize(operandType(IC_RESULT(ic))) > 1)
1892 /* has only one definition */
1893 if (bitVectnBitsOn(OP_DEFS(IC_RESULT(ic))) > 1)
1896 /* has only one use */
1897 if (bitVectnBitsOn(OP_USES(IC_RESULT(ic))) > 1)
1900 /* and the usage immediately follows this iCode */
1901 if (!(uic = hTabItemWithKey(iCodehTab,
1902 bitVectFirstBit(OP_USES(IC_RESULT(ic))))))
1905 if (ic->next != uic)
1908 /* if it is a conditional branch then we definitely can */
1909 if (uic->op == IFX )
1912 if ( uic->op == JUMPTABLE )
1915 /* if the usage is not is an assignment
1916 or an arithmetic / bitwise / shift operation then not */
1917 if (POINTER_SET(uic) &&
1918 getSize(aggrToPtr(operandType(IC_RESULT(uic)),FALSE)) > 1)
1921 if (uic->op != '=' &&
1922 !IS_ARITHMETIC_OP(uic) &&
1923 !IS_BITWISE_OP(uic) &&
1924 uic->op != LEFT_OP &&
1925 uic->op != RIGHT_OP )
1928 /* if used in ^ operation then make sure right is not a
1930 if (uic->op == '^' && isOperandLiteral(IC_RIGHT(uic)))
1933 /* if shift operation make sure right side is not a literal */
1934 if (uic->op == RIGHT_OP &&
1935 ( isOperandLiteral(IC_RIGHT(uic)) ||
1936 getSize(operandType(IC_RESULT(uic))) > 1))
1939 if (uic->op == LEFT_OP &&
1940 ( isOperandLiteral(IC_RIGHT(uic)) ||
1941 getSize(operandType(IC_RESULT(uic))) > 1))
1944 /* make sure that the result of this icode is not on the
1945 stack, since acc is used to compute stack offset */
1946 if (IS_TRUE_SYMOP(IC_RESULT(uic)) &&
1947 OP_SYMBOL(IC_RESULT(uic))->onStack)
1950 /* if either one of them in far space then we cannot */
1951 if ((IS_TRUE_SYMOP(IC_LEFT(uic)) &&
1952 isOperandInFarSpace(IC_LEFT(uic))) ||
1953 (IS_TRUE_SYMOP(IC_RIGHT(uic)) &&
1954 isOperandInFarSpace(IC_RIGHT(uic))))
1957 /* if the usage has only one operand then we can */
1958 if (IC_LEFT(uic) == NULL ||
1959 IC_RIGHT(uic) == NULL)
1962 /* make sure this is on the left side if not
1963 a '+' since '+' is commutative */
1964 if (ic->op != '+' &&
1965 IC_LEFT(uic)->key != IC_RESULT(ic)->key)
1968 /* if one of them is a literal then we can */
1969 if ((IC_LEFT(uic) && IS_OP_LITERAL(IC_LEFT(uic))) ||
1970 (IC_RIGHT(uic) && IS_OP_LITERAL(IC_RIGHT(uic)))) {
1971 OP_SYMBOL(IC_RESULT(ic))->accuse = 1;
1975 /* if the other one is not on stack then we can */
1976 if (IC_LEFT(uic)->key == IC_RESULT(ic)->key &&
1977 (IS_ITEMP(IC_RIGHT(uic)) ||
1978 (IS_TRUE_SYMOP(IC_RIGHT(uic)) &&
1979 !OP_SYMBOL(IC_RIGHT(uic))->onStack)))
1982 if (IC_RIGHT(uic)->key == IC_RESULT(ic)->key &&
1983 (IS_ITEMP(IC_LEFT(uic)) ||
1984 (IS_TRUE_SYMOP(IC_LEFT(uic)) &&
1985 !OP_SYMBOL(IC_LEFT(uic))->onStack)))
1991 OP_SYMBOL(IC_RESULT(ic))->accuse = 1;
1996 /*-----------------------------------------------------------------*/
1997 /* packForPush - hueristics to reduce iCode for pushing */
1998 /*-----------------------------------------------------------------*/
1999 static void packForPush(iCode *ic, eBBlock *ebp)
2003 if (ic->op != IPUSH || !IS_ITEMP(IC_LEFT(ic)))
2006 /* must have only definition & one usage */
2007 if (bitVectnBitsOn(OP_DEFS(IC_LEFT(ic))) != 1 ||
2008 bitVectnBitsOn(OP_USES(IC_LEFT(ic))) != 1 )
2011 /* find the definition */
2012 if (!(dic = hTabItemWithKey(iCodehTab,
2013 bitVectFirstBit(OP_DEFS(IC_LEFT(ic))))))
2016 if (dic->op != '=' || POINTER_SET(dic))
2019 /* we now we know that it has one & only one def & use
2020 and the that the definition is an assignment */
2021 IC_LEFT(ic) = IC_RIGHT(dic);
2023 remiCodeFromeBBlock(ebp,dic);
2024 hTabDeleteItem (&iCodehTab,dic->key,dic,DELETE_ITEM,NULL);
2027 /*-----------------------------------------------------------------*/
2028 /* packRegisters - does some transformations to reduce register */
2030 /*-----------------------------------------------------------------*/
2031 static void packRegisters (eBBlock *ebp)
2040 /* look for assignments of the form */
2041 /* iTempNN = TRueSym (someoperation) SomeOperand */
2043 /* TrueSym := iTempNN:1 */
2044 for ( ic = ebp->sch ; ic ; ic = ic->next ) {
2047 /* find assignment of the form TrueSym := iTempNN:1 */
2048 if (ic->op == '=' && !POINTER_SET(ic))
2049 change += packRegsForAssign(ic,ebp);
2056 for ( ic = ebp->sch ; ic ; ic = ic->next ) {
2058 /* if this is an itemp & result of a address of a true sym
2059 then mark this as rematerialisable */
2060 if (ic->op == ADDRESS_OF &&
2061 IS_ITEMP(IC_RESULT(ic)) &&
2062 IS_TRUE_SYMOP(IC_LEFT(ic)) &&
2063 bitVectnBitsOn(OP_DEFS(IC_RESULT(ic))) == 1 &&
2064 !OP_SYMBOL(IC_LEFT(ic))->onStack ) {
2066 OP_SYMBOL(IC_RESULT(ic))->remat = 1;
2067 OP_SYMBOL(IC_RESULT(ic))->rematiCode = ic;
2068 OP_SYMBOL(IC_RESULT(ic))->usl.spillLoc = NULL;
2072 /* if straight assignment then carry remat flag if
2073 this is the only definition */
2074 if (ic->op == '=' &&
2076 IS_SYMOP(IC_RIGHT(ic)) &&
2077 OP_SYMBOL(IC_RIGHT(ic))->remat &&
2078 bitVectnBitsOn(OP_SYMBOL(IC_RESULT(ic))->defs) <= 1) {
2080 OP_SYMBOL(IC_RESULT(ic))->remat =
2081 OP_SYMBOL(IC_RIGHT(ic))->remat;
2082 OP_SYMBOL(IC_RESULT(ic))->rematiCode =
2083 OP_SYMBOL(IC_RIGHT(ic))->rematiCode ;
2086 /* if this is a +/- operation with a rematerizable
2087 then mark this as rematerializable as well only
2088 if the literal value is within the range -255 and + 255
2089 the assembler cannot handle it other wise */
2090 if ((ic->op == '+' || ic->op == '-') &&
2092 (IS_SYMOP(IC_LEFT(ic)) &&
2093 IS_ITEMP(IC_RESULT(ic)) &&
2094 OP_SYMBOL(IC_LEFT(ic))->remat &&
2095 bitVectnBitsOn(OP_DEFS(IC_RESULT(ic))) == 1 &&
2096 IS_OP_LITERAL(IC_RIGHT(ic))) ) {
2098 int i = operandLitValue(IC_RIGHT(ic));
2099 if ( i < 255 && i > -255) {
2100 OP_SYMBOL(IC_RESULT(ic))->remat = 1;
2101 OP_SYMBOL(IC_RESULT(ic))->rematiCode = ic;
2102 OP_SYMBOL(IC_RESULT(ic))->usl.spillLoc = NULL;
2106 /* mark the pointer usages */
2107 if (POINTER_SET(ic))
2108 OP_SYMBOL(IC_RESULT(ic))->uptr = 1;
2110 if (POINTER_GET(ic))
2111 OP_SYMBOL(IC_LEFT(ic))->uptr = 1;
2113 /* if the condition of an if instruction
2114 is defined in the previous instruction then
2115 mark the itemp as a conditional */
2116 if ((IS_CONDITIONAL(ic) ||
2117 ( ( ic->op == BITWISEAND ||
2120 isBitwiseOptimizable(ic))) &&
2121 ic->next && ic->next->op == IFX &&
2122 isOperandEqual(IC_RESULT(ic),IC_COND(ic->next)) &&
2123 OP_SYMBOL(IC_RESULT(ic))->liveTo <= ic->next->seq) {
2125 OP_SYMBOL(IC_RESULT(ic))->regType = REG_CND;
2129 /* reduce for support function calls */
2130 /* if (ic->supportRtn || ic->op == '+' || ic->op == '-' ) */
2131 /* packRegsForSupport (ic,ebp); */
2133 /* some cases the redundant moves can
2134 can be eliminated for return statements */
2135 /* if ((ic->op == RETURN || ic->op == SEND) && */
2136 /* !isOperandInFarSpace(IC_LEFT(ic)) && */
2137 /* !options.model) */
2138 /* packRegsForOneuse (ic,IC_LEFT(ic),ebp); */
2140 /* if pointer set & left has a size more than
2141 one and right is not in far space */
2142 /* if (POINTER_SET(ic) && */
2143 /* !isOperandInFarSpace(IC_RIGHT(ic)) && */
2144 /* !OP_SYMBOL(IC_RESULT(ic))->remat && */
2145 /* !IS_OP_RUONLY(IC_RIGHT(ic)) && */
2146 /* getSize(aggrToPtr(operandType(IC_RESULT(ic)),FALSE)) > 1 ) */
2148 /* packRegsForOneuse (ic,IC_RESULT(ic),ebp); */
2150 /* if pointer get */
2151 /* if (POINTER_GET(ic) && */
2152 /* !isOperandInFarSpace(IC_RESULT(ic))&& */
2153 /* !OP_SYMBOL(IC_LEFT(ic))->remat && */
2154 /* !IS_OP_RUONLY(IC_RESULT(ic)) && */
2155 /* getSize(aggrToPtr(operandType(IC_LEFT(ic)),FALSE)) > 1 ) */
2157 /* packRegsForOneuse (ic,IC_LEFT(ic),ebp); */
2160 /* if this is cast for intergral promotion then
2161 check if only use of the definition of the
2162 operand being casted/ if yes then replace
2163 the result of that arithmetic operation with
2164 this result and get rid of the cast */
2165 if (ic->op == CAST) {
2166 link *fromType = operandType(IC_RIGHT(ic));
2167 link *toType = operandType(IC_LEFT(ic));
2169 if (IS_INTEGRAL(fromType) && IS_INTEGRAL(toType) &&
2170 getSize(fromType) != getSize(toType) ) {
2172 iCode *dic = packRegsForOneuse(ic,IC_RIGHT(ic),ebp);
2174 if (IS_ARITHMETIC_OP(dic)) {
2175 IC_RESULT(dic) = IC_RESULT(ic);
2176 remiCodeFromeBBlock(ebp,ic);
2177 hTabDeleteItem (&iCodehTab,ic->key,ic,DELETE_ITEM,NULL);
2180 OP_SYMBOL(IC_RIGHT(ic))->ruonly = 0;
2184 /* if the type from and type to are the same
2185 then if this is the only use then packit */
2186 if (checkType(operandType(IC_RIGHT(ic)),
2187 operandType(IC_LEFT(ic))) == 1) {
2188 iCode *dic = packRegsForOneuse (ic,IC_RIGHT(ic),ebp);
2190 IC_RESULT(dic) = IC_RESULT(ic);
2191 remiCodeFromeBBlock(ebp,ic);
2192 hTabDeleteItem (&iCodehTab,ic->key,ic,DELETE_ITEM,NULL);
2200 iTempNN := (some variable in farspace) V1
2205 /* if (ic->op == IPUSH ) { */
2206 /* packForPush(ic,ebp); */
2210 /* pack registers for accumulator use, when the
2211 result of an arithmetic or bit wise operation
2212 has only one use, that use is immediately following
2213 the defintion and the using iCode has only one
2214 operand or has two operands but one is literal &
2215 the result of that operation is not on stack then
2216 we can leave the result of this operation in acc:b
2218 /* if ((IS_ARITHMETIC_OP(ic) */
2220 /* || IS_BITWISE_OP(ic) */
2222 /* || ic->op == LEFT_OP || ic->op == RIGHT_OP */
2225 /* IS_ITEMP(IC_RESULT(ic)) && */
2226 /* getSize(operandType(IC_RESULT(ic))) <= 2) */
2228 /* packRegsForAccUse (ic); */
2233 /*-----------------------------------------------------------------*/
2234 /* assignRegisters - assigns registers to each live range as need */
2235 /*-----------------------------------------------------------------*/
2236 void avr_assignRegisters (eBBlock **ebbs, int count)
2241 setToNull((void *)&_G.funcrUsed);
2242 avr_ptrRegReq = _G.stackExtend = _G.dataExtend = 0;
2244 /* is a leaf function then we can allocate the
2245 parameter registers as well */
2246 if (!currFunc->hasFcall)
2250 /* change assignments this will remove some
2251 live ranges reducing some register pressure */
2252 for (i = 0 ; i < count ;i++ )
2253 packRegisters (ebbs[i]);
2255 if (options.dump_pack)
2256 dumpEbbsToFileExt(".dumppack",ebbs,count);
2258 /* first determine for each live range the number of
2259 registers & the type of registers required for each */
2262 /* and serially allocate registers */
2263 serialRegAssign(ebbs,count);
2265 /* if stack was extended then tell the user */
2266 if (_G.stackExtend) {
2267 /* werror(W_TOOMANY_SPILS,"stack", */
2268 /* _G.stackExtend,currFunc->name,""); */
2269 _G.stackExtend = 0 ;
2272 if (_G.dataExtend) {
2273 /* werror(W_TOOMANY_SPILS,"data space", */
2274 /* _G.dataExtend,currFunc->name,""); */
2278 /* after that create the register mask
2279 for each of the instruction */
2280 createRegMask (ebbs,count);
2282 /* redo that offsets for stacked automatic variables */
2283 redoStackOffsets ();
2285 if (options.dump_rassgn)
2286 dumpEbbsToFileExt(".dumprassgn",ebbs,count);
2288 /* now get back the chain */
2289 ic = iCodeLabelOptimize(iCodeFromeBBlock (ebbs,count));
2294 /* free up any _G.stackSpil locations allocated */
2295 applyToSet(_G.stackSpil,deallocStackSpil);
2297 setToNull((void **)&_G.stackSpil);
2298 setToNull((void **)&_G.spiltSet);
2299 /* mark all registers as free */