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 /*-----------------------------------------------------------------*/
47 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 /*-----------------------------------------------------------------*/
86 for (i = 0; i < ds390_nRegs; i++)
89 /* if type is given as 0 then any
90 free register will do */
94 regs390[i].isFree = 0;
97 bitVectSetBit (currFunc->regsUsed, i);
100 /* other wise look for specific type
102 if (regs390[i].isFree &&
103 regs390[i].type == type)
105 regs390[i].isFree = 0;
108 bitVectSetBit (currFunc->regsUsed, i);
115 /*-----------------------------------------------------------------*/
116 /* ds390_regWithIdx - returns pointer to register wit index number */
117 /*-----------------------------------------------------------------*/
119 ds390_regWithIdx (int idx)
123 for (i = 0; i < ds390_nRegs; i++)
124 if (regs390[i].rIdx == idx)
127 werror (E_INTERNAL_ERROR, __FILE__, __LINE__,
128 "regWithIdx not found");
132 /*-----------------------------------------------------------------*/
133 /* freeReg - frees a register */
134 /*-----------------------------------------------------------------*/
142 /*-----------------------------------------------------------------*/
143 /* nFreeRegs - returns number of free registers */
144 /*-----------------------------------------------------------------*/
151 for (i = 0; i < ds390_nRegs; i++)
152 if (regs390[i].isFree && regs390[i].type == type)
157 /*-----------------------------------------------------------------*/
158 /* nfreeRegsType - free registers with type */
159 /*-----------------------------------------------------------------*/
161 nfreeRegsType (int type)
166 if ((nfr = nFreeRegs (type)) == 0)
167 return nFreeRegs (REG_GPR);
170 return nFreeRegs (type);
174 /*-----------------------------------------------------------------*/
175 /* allDefsOutOfRange - all definitions are out of a range */
176 /*-----------------------------------------------------------------*/
178 allDefsOutOfRange (bitVect * defs, int fseq, int toseq)
185 for (i = 0; i < defs->size; i++)
189 if (bitVectBitValue (defs, i) &&
190 (ic = hTabItemWithKey (iCodehTab, i)) &&
191 (ic->seq >= fseq && ic->seq <= toseq))
200 /*-----------------------------------------------------------------*/
201 /* computeSpillable - given a point find the spillable live ranges */
202 /*-----------------------------------------------------------------*/
204 computeSpillable (iCode * ic)
208 /* spillable live ranges are those that are live at this
209 point . the following categories need to be subtracted
211 a) - those that are already spilt
212 b) - if being used by this one
213 c) - defined by this one */
215 spillable = bitVectCopy (ic->rlive);
217 bitVectCplAnd (spillable, _G.spiltSet); /* those already spilt */
219 bitVectCplAnd (spillable, ic->uses); /* used in this one */
220 bitVectUnSetBit (spillable, ic->defKey);
221 spillable = bitVectIntersect (spillable, _G.regAssigned);
226 /*-----------------------------------------------------------------*/
227 /* noSpilLoc - return true if a variable has no spil location */
228 /*-----------------------------------------------------------------*/
230 noSpilLoc (symbol * sym, eBBlock * ebp, iCode * ic)
232 return (sym->usl.spillLoc ? 0 : 1);
235 /*-----------------------------------------------------------------*/
236 /* hasSpilLoc - will return 1 if the symbol has spil location */
237 /*-----------------------------------------------------------------*/
239 hasSpilLoc (symbol * sym, eBBlock * ebp, iCode * ic)
241 return (sym->usl.spillLoc ? 1 : 0);
244 /*-----------------------------------------------------------------*/
245 /* directSpilLoc - will return 1 if the splilocation is in direct */
246 /*-----------------------------------------------------------------*/
248 directSpilLoc (symbol * sym, eBBlock * ebp, iCode * ic)
250 if (sym->usl.spillLoc &&
251 (IN_DIRSPACE (SPEC_OCLS (sym->usl.spillLoc->etype))))
257 /*-----------------------------------------------------------------*/
258 /* hasSpilLocnoUptr - will return 1 if the symbol has spil location */
259 /* but is not used as a pointer */
260 /*-----------------------------------------------------------------*/
262 hasSpilLocnoUptr (symbol * sym, eBBlock * ebp, iCode * ic)
264 return ((sym->usl.spillLoc && !sym->uptr) ? 1 : 0);
267 /*-----------------------------------------------------------------*/
268 /* rematable - will return 1 if the remat flag is set */
269 /*-----------------------------------------------------------------*/
271 rematable (symbol * sym, eBBlock * ebp, iCode * ic)
276 /*-----------------------------------------------------------------*/
277 /* notUsedInBlock - not used in this block */
278 /*-----------------------------------------------------------------*/
280 notUsedInBlock (symbol * sym, eBBlock * ebp, iCode * ic)
282 return (!bitVectBitsInCommon (sym->defs, ebp->usesDefs) &&
283 allDefsOutOfRange (sym->defs, ebp->fSeq, ebp->lSeq));
284 /* return (!bitVectBitsInCommon(sym->defs,ebp->usesDefs)); */
287 /*-----------------------------------------------------------------*/
288 /* notUsedInRemaining - not used or defined in remain of the block */
289 /*-----------------------------------------------------------------*/
291 notUsedInRemaining (symbol * sym, eBBlock * ebp, iCode * ic)
293 return ((usedInRemaining (operandFromSymbol (sym), ic) ? 0 : 1) &&
294 allDefsOutOfRange (sym->defs, ebp->fSeq, ebp->lSeq));
297 /*-----------------------------------------------------------------*/
298 /* allLRs - return true for all */
299 /*-----------------------------------------------------------------*/
301 allLRs (symbol * sym, eBBlock * ebp, iCode * ic)
306 /*-----------------------------------------------------------------*/
307 /* liveRangesWith - applies function to a given set of live range */
308 /*-----------------------------------------------------------------*/
310 liveRangesWith (bitVect * lrs, int (func) (symbol *, eBBlock *, iCode *),
311 eBBlock * ebp, iCode * ic)
316 if (!lrs || !lrs->size)
319 for (i = 1; i < lrs->size; i++)
322 if (!bitVectBitValue (lrs, i))
325 /* if we don't find it in the live range
326 hash table we are in serious trouble */
327 if (!(sym = hTabItemWithKey (liveRanges, i)))
329 werror (E_INTERNAL_ERROR, __FILE__, __LINE__,
330 "liveRangesWith could not find liveRange");
334 if (func (sym, ebp, ic) && bitVectBitValue (_G.regAssigned, sym->key))
335 addSetHead (&rset, sym);
342 /*-----------------------------------------------------------------*/
343 /* leastUsedLR - given a set determines which is the least used */
344 /*-----------------------------------------------------------------*/
346 leastUsedLR (set * sset)
348 symbol *sym = NULL, *lsym = NULL;
350 sym = lsym = setFirstItem (sset);
355 for (; lsym; lsym = setNextItem (sset))
358 /* if usage is the same then prefer
359 the spill the smaller of the two */
360 if (lsym->used == sym->used)
361 if (getSize (lsym->type) < getSize (sym->type))
365 if (lsym->used < sym->used)
370 setToNull ((void **) &sset);
375 /*-----------------------------------------------------------------*/
376 /* noOverLap - will iterate through the list looking for over lap */
377 /*-----------------------------------------------------------------*/
379 noOverLap (set * itmpStack, symbol * fsym)
383 for (sym = setFirstItem (itmpStack); sym;
384 sym = setNextItem (itmpStack))
386 // if sym starts before (or on) our end point
387 // and ends after (or on) our start point,
389 if (sym->liveFrom <= fsym->liveTo &&
390 sym->liveTo >= fsym->liveFrom)
398 /*-----------------------------------------------------------------*/
399 /* isFree - will return 1 if the a free spil location is found */
400 /*-----------------------------------------------------------------*/
405 V_ARG (symbol **, sloc);
406 V_ARG (symbol *, fsym);
408 /* if already found */
412 /* if it is free && and the itmp assigned to
413 this does not have any overlapping live ranges
414 with the one currently being assigned and
415 the size can be accomodated */
417 noOverLap (sym->usl.itmpStack, fsym) &&
418 getSize (sym->type) >= getSize (fsym->type))
427 /*-----------------------------------------------------------------*/
428 /* spillLRWithPtrReg :- will spil those live ranges which use PTR */
429 /*-----------------------------------------------------------------*/
431 spillLRWithPtrReg (symbol * forSym)
437 if (!_G.regAssigned ||
438 bitVectIsZero (_G.regAssigned))
441 r0 = ds390_regWithIdx (R0_IDX);
442 r1 = ds390_regWithIdx (R1_IDX);
444 /* for all live ranges */
445 for (lrsym = hTabFirstItem (liveRanges, &k); lrsym;
446 lrsym = hTabNextItem (liveRanges, &k))
450 /* if no registers assigned to it or
452 /* if it does not overlap with this then
453 not need to spill it */
455 if (lrsym->isspilt || !lrsym->nRegs ||
456 (lrsym->liveTo < forSym->liveFrom))
459 /* go thru the registers : if it is either
460 r0 or r1 then spil it */
461 for (j = 0; j < lrsym->nRegs; j++)
462 if (lrsym->regs[j] == r0 ||
463 lrsym->regs[j] == r1)
472 /*-----------------------------------------------------------------*/
473 /* createStackSpil - create a location on the stack to spil */
474 /*-----------------------------------------------------------------*/
476 createStackSpil (symbol * sym)
479 int useXstack, model, noOverlay;
483 /* first go try and find a free one that is already
484 existing on the stack */
485 if (applyToSet (_G.stackSpil, isFree, &sloc, sym))
487 /* found a free one : just update & return */
488 sym->usl.spillLoc = sloc;
491 addSetHead (&sloc->usl.itmpStack, sym);
495 /* could not then have to create one , this is the hard part
496 we need to allocate this on the stack : this is really a
497 hack!! but cannot think of anything better at this time */
499 if (sprintf (slocBuffer, "sloc%d", _G.slocNum++) >= sizeof (slocBuffer))
501 fprintf (stderr, "***Internal error: slocBuffer overflowed: %s:%d\n",
506 sloc = newiTemp (slocBuffer);
508 /* set the type to the spilling symbol */
509 sloc->type = copyLinkChain (sym->type);
510 sloc->etype = getSpec (sloc->type);
511 if (options.model == MODEL_SMALL) {
512 SPEC_SCLS (sloc->etype) = S_DATA;
514 SPEC_SCLS (sloc->etype) = S_XDATA;
516 SPEC_EXTR (sloc->etype) = 0;
518 /* we don't allow it to be allocated`
519 onto the external stack since : so we
520 temporarily turn it off ; we also
521 turn off memory model to prevent
522 the spil from going to the external storage
523 and turn off overlaying
526 useXstack = options.useXstack;
527 model = options.model;
528 noOverlay = options.noOverlay;
529 options.noOverlay = 1;
531 /* options.model = options.useXstack = 0; */
535 options.useXstack = useXstack;
536 options.model = model;
537 options.noOverlay = noOverlay;
538 sloc->isref = 1; /* to prevent compiler warning */
540 /* if it is on the stack then update the stack */
541 if (IN_STACK (sloc->etype))
543 currFunc->stack += getSize (sloc->type);
544 _G.stackExtend += getSize (sloc->type);
547 _G.dataExtend += getSize (sloc->type);
549 /* add it to the _G.stackSpil set */
550 addSetHead (&_G.stackSpil, sloc);
551 sym->usl.spillLoc = sloc;
554 /* add it to the set of itempStack set
555 of the spill location */
556 addSetHead (&sloc->usl.itmpStack, sym);
560 /*-----------------------------------------------------------------*/
561 /* isSpiltOnStack - returns true if the spil location is on stack */
562 /*-----------------------------------------------------------------*/
564 isSpiltOnStack (symbol * sym)
574 /* if (sym->_G.stackSpil) */
577 if (!sym->usl.spillLoc)
580 etype = getSpec (sym->usl.spillLoc->type);
581 if (IN_STACK (etype))
587 /*-----------------------------------------------------------------*/
588 /* spillThis - spils a specific operand */
589 /*-----------------------------------------------------------------*/
591 spillThis (symbol * sym)
594 /* if this is rematerializable or has a spillLocation
595 we are okay, else we need to create a spillLocation
597 if (!(sym->remat || sym->usl.spillLoc))
598 createStackSpil (sym);
601 /* mark it has spilt & put it in the spilt set */
603 _G.spiltSet = bitVectSetBit (_G.spiltSet, sym->key);
605 bitVectUnSetBit (_G.regAssigned, sym->key);
607 for (i = 0; i < sym->nRegs; i++)
611 freeReg (sym->regs[i]);
615 /* if spilt on stack then free up r0 & r1
616 if they could have been assigned to some
618 if (!ds390_ptrRegReq && isSpiltOnStack (sym))
620 ds390_ptrRegReq += !options.stack10bit;
621 spillLRWithPtrReg (sym);
624 if (sym->usl.spillLoc && !sym->remat)
625 sym->usl.spillLoc->allocreq = 1;
629 /*-----------------------------------------------------------------*/
630 /* selectSpil - select a iTemp to spil : rather a simple procedure */
631 /*-----------------------------------------------------------------*/
633 selectSpil (iCode * ic, eBBlock * ebp, symbol * forSym)
635 bitVect *lrcs = NULL;
639 /* get the spillable live ranges */
640 lrcs = computeSpillable (ic);
642 /* get all live ranges that are rematerizable */
643 if ((selectS = liveRangesWith (lrcs, rematable, ebp, ic)))
646 /* return the least used of these */
647 return leastUsedLR (selectS);
650 /* get live ranges with spillLocations in direct space */
651 if ((selectS = liveRangesWith (lrcs, directSpilLoc, ebp, ic)))
653 sym = leastUsedLR (selectS);
654 strcpy (sym->rname, (sym->usl.spillLoc->rname[0] ?
655 sym->usl.spillLoc->rname :
656 sym->usl.spillLoc->name));
658 /* mark it as allocation required */
659 sym->usl.spillLoc->allocreq = 1;
663 /* if the symbol is local to the block then */
664 if (forSym->liveTo < ebp->lSeq)
667 /* check if there are any live ranges allocated
668 to registers that are not used in this block */
669 if (!_G.blockSpil && (selectS = liveRangesWith (lrcs, notUsedInBlock, ebp, ic)))
671 sym = leastUsedLR (selectS);
672 /* if this is not rematerializable */
681 /* check if there are any live ranges that not
682 used in the remainder of the block */
683 if (!_G.blockSpil && (selectS = liveRangesWith (lrcs, notUsedInRemaining, ebp, ic)))
685 sym = leastUsedLR (selectS);
698 /* find live ranges with spillocation && not used as pointers */
699 if ((selectS = liveRangesWith (lrcs, hasSpilLocnoUptr, ebp, ic)))
702 sym = leastUsedLR (selectS);
703 /* mark this as allocation required */
704 sym->usl.spillLoc->allocreq = 1;
708 /* find live ranges with spillocation */
709 if ((selectS = liveRangesWith (lrcs, hasSpilLoc, ebp, ic)))
712 sym = leastUsedLR (selectS);
713 sym->usl.spillLoc->allocreq = 1;
717 /* couldn't find then we need to create a spil
718 location on the stack , for which one? the least
720 if ((selectS = liveRangesWith (lrcs, noSpilLoc, ebp, ic)))
723 /* return a created spil location */
724 sym = createStackSpil (leastUsedLR (selectS));
725 sym->usl.spillLoc->allocreq = 1;
729 /* this is an extreme situation we will spill
730 this one : happens very rarely but it does happen */
736 /*-----------------------------------------------------------------*/
737 /* spilSomething - spil some variable & mark registers as free */
738 /*-----------------------------------------------------------------*/
740 spilSomething (iCode * ic, eBBlock * ebp, symbol * forSym)
745 /* get something we can spil */
746 ssym = selectSpil (ic, ebp, forSym);
748 /* mark it as spilt */
750 _G.spiltSet = bitVectSetBit (_G.spiltSet, ssym->key);
752 /* mark it as not register assigned &
753 take it away from the set */
754 bitVectUnSetBit (_G.regAssigned, ssym->key);
756 /* mark the registers as free */
757 for (i = 0; i < ssym->nRegs; i++)
759 freeReg (ssym->regs[i]);
761 /* if spilt on stack then free up r0 & r1
762 if they could have been assigned to as gprs */
763 if (!ds390_ptrRegReq && isSpiltOnStack (ssym) && !options.stack10bit)
766 spillLRWithPtrReg (ssym);
769 /* if this was a block level spil then insert push & pop
770 at the start & end of block respectively */
773 iCode *nic = newiCode (IPUSH, operandFromSymbol (ssym), NULL);
774 /* add push to the start of the block */
775 addiCodeToeBBlock (ebp, nic, (ebp->sch->op == LABEL ?
776 ebp->sch->next : ebp->sch));
777 nic = newiCode (IPOP, operandFromSymbol (ssym), NULL);
778 /* add pop to the end of the block */
779 addiCodeToeBBlock (ebp, nic, NULL);
782 /* if spilt because not used in the remainder of the
783 block then add a push before this instruction and
784 a pop at the end of the block */
785 if (ssym->remainSpil)
788 iCode *nic = newiCode (IPUSH, operandFromSymbol (ssym), NULL);
789 /* add push just before this instruction */
790 addiCodeToeBBlock (ebp, nic, ic);
792 nic = newiCode (IPOP, operandFromSymbol (ssym), NULL);
793 /* add pop to the end of the block */
794 addiCodeToeBBlock (ebp, nic, NULL);
803 /*-----------------------------------------------------------------*/
804 /* getRegPtr - will try for PTR if not a GPR type if not spil */
805 /*-----------------------------------------------------------------*/
807 getRegPtr (iCode * ic, eBBlock * ebp, symbol * sym)
812 /* try for a ptr type */
813 if ((reg = allocReg (REG_PTR)))
816 /* try for gpr type */
817 if ((reg = allocReg (REG_GPR)))
820 /* we have to spil */
821 if (!spilSomething (ic, ebp, sym))
824 /* this looks like an infinite loop but
825 in really selectSpil will abort */
829 /*-----------------------------------------------------------------*/
830 /* getRegGpr - will try for GPR if not spil */
831 /*-----------------------------------------------------------------*/
833 getRegGpr (iCode * ic, eBBlock * ebp, symbol * sym)
838 /* try for gpr type */
839 if ((reg = allocReg (REG_GPR)))
842 if (!ds390_ptrRegReq)
843 if ((reg = allocReg (REG_PTR)))
846 /* we have to spil */
847 if (!spilSomething (ic, ebp, sym))
850 /* this looks like an infinite loop but
851 in really selectSpil will abort */
855 /*-----------------------------------------------------------------*/
856 /* symHasReg - symbol has a given register */
857 /*-----------------------------------------------------------------*/
859 symHasReg (symbol * sym, regs * reg)
863 for (i = 0; i < sym->nRegs; i++)
864 if (sym->regs[i] == reg)
870 /*-----------------------------------------------------------------*/
871 /* deassignLRs - check the live to and if they have registers & are */
872 /* not spilt then free up the registers */
873 /*-----------------------------------------------------------------*/
875 deassignLRs (iCode * ic, eBBlock * ebp)
881 for (sym = hTabFirstItem (liveRanges, &k); sym;
882 sym = hTabNextItem (liveRanges, &k))
886 /* if it does not end here */
887 if (sym->liveTo > ic->seq)
890 /* if it was spilt on stack then we can
891 mark the stack spil location as free */
896 sym->usl.spillLoc->isFree = 1;
902 if (!bitVectBitValue (_G.regAssigned, sym->key))
905 /* special case check if this is an IFX &
906 the privious one was a pop and the
907 previous one was not spilt then keep track
909 if (ic->op == IFX && ic->prev &&
910 ic->prev->op == IPOP &&
911 !ic->prev->parmPush &&
912 !OP_SYMBOL (IC_LEFT (ic->prev))->isspilt)
913 psym = OP_SYMBOL (IC_LEFT (ic->prev));
919 bitVectUnSetBit (_G.regAssigned, sym->key);
921 /* if the result of this one needs registers
922 and does not have it then assign it right
924 if (IC_RESULT (ic) &&
925 !(SKIP_IC2 (ic) || /* not a special icode */
926 ic->op == JUMPTABLE ||
932 (result = OP_SYMBOL (IC_RESULT (ic))) && /* has a result */
933 result->liveTo > ic->seq && /* and will live beyond this */
934 result->liveTo <= ebp->lSeq && /* does not go beyond this block */
935 result->regType == sym->regType && /* same register types */
936 result->nRegs && /* which needs registers */
937 !result->isspilt && /* and does not already have them */
939 !bitVectBitValue (_G.regAssigned, result->key) &&
940 /* the number of free regs + number of regs in this LR
941 can accomodate the what result Needs */
942 ((nfreeRegsType (result->regType) +
943 sym->nRegs) >= result->nRegs)
947 for (i = 0; i < result->nRegs; i++)
949 result->regs[i] = sym->regs[i];
951 result->regs[i] = getRegGpr (ic, ebp, result);
953 _G.regAssigned = bitVectSetBit (_G.regAssigned, result->key);
957 /* free the remaining */
958 for (; i < sym->nRegs; i++)
962 if (!symHasReg (psym, sym->regs[i]))
963 freeReg (sym->regs[i]);
966 freeReg (sym->regs[i]);
973 /*-----------------------------------------------------------------*/
974 /* reassignLR - reassign this to registers */
975 /*-----------------------------------------------------------------*/
977 reassignLR (operand * op)
979 symbol *sym = OP_SYMBOL (op);
982 /* not spilt any more */
983 sym->isspilt = sym->blockSpil = sym->remainSpil = 0;
984 bitVectUnSetBit (_G.spiltSet, sym->key);
986 _G.regAssigned = bitVectSetBit (_G.regAssigned, sym->key);
990 for (i = 0; i < sym->nRegs; i++)
991 sym->regs[i]->isFree = 0;
994 /*-----------------------------------------------------------------*/
995 /* willCauseSpill - determines if allocating will cause a spill */
996 /*-----------------------------------------------------------------*/
998 willCauseSpill (int nr, int rt)
1000 /* first check if there are any avlb registers
1001 of te type required */
1004 /* special case for pointer type
1005 if pointer type not avlb then
1006 check for type gpr */
1007 if (nFreeRegs (rt) >= nr)
1009 if (nFreeRegs (REG_GPR) >= nr)
1014 if (ds390_ptrRegReq)
1016 if (nFreeRegs (rt) >= nr)
1021 if (nFreeRegs (REG_PTR) +
1022 nFreeRegs (REG_GPR) >= nr)
1027 /* it will cause a spil */
1031 /*-----------------------------------------------------------------*/
1032 /* positionRegs - the allocator can allocate same registers to res- */
1033 /* ult and operand, if this happens make sure they are in the same */
1034 /* position as the operand otherwise chaos results */
1035 /*-----------------------------------------------------------------*/
1037 positionRegs (symbol * result, symbol * opsym, int lineno)
1039 int count = min (result->nRegs, opsym->nRegs);
1040 int i, j = 0, shared = 0;
1042 /* if the result has been spilt then cannot share */
1047 /* first make sure that they actually share */
1048 for (i = 0; i < count; i++)
1050 for (j = 0; j < count; j++)
1052 if (result->regs[i] == opsym->regs[j] && i != j)
1062 regs *tmp = result->regs[i];
1063 result->regs[i] = result->regs[j];
1064 result->regs[j] = tmp;
1069 /*-----------------------------------------------------------------*/
1070 /* serialRegAssign - serially allocate registers to the variables */
1071 /*-----------------------------------------------------------------*/
1073 serialRegAssign (eBBlock ** ebbs, int count)
1077 /* for all blocks */
1078 for (i = 0; i < count; i++)
1083 if (ebbs[i]->noPath &&
1084 (ebbs[i]->entryLabel != entryLabel &&
1085 ebbs[i]->entryLabel != returnLabel))
1088 /* of all instructions do */
1089 for (ic = ebbs[i]->sch; ic; ic = ic->next)
1092 /* if this is an ipop that means some live
1093 range will have to be assigned again */
1095 reassignLR (IC_LEFT (ic));
1097 /* if result is present && is a true symbol */
1098 if (IC_RESULT (ic) && ic->op != IFX &&
1099 IS_TRUE_SYMOP (IC_RESULT (ic)))
1100 OP_SYMBOL (IC_RESULT (ic))->allocreq = 1;
1102 /* take away registers from live
1103 ranges that end at this instruction */
1104 deassignLRs (ic, ebbs[i]);
1106 /* some don't need registers */
1107 if (SKIP_IC2 (ic) ||
1108 ic->op == JUMPTABLE ||
1112 (IC_RESULT (ic) && POINTER_SET (ic)))
1115 /* now we need to allocate registers
1116 only for the result */
1119 symbol *sym = OP_SYMBOL (IC_RESULT (ic));
1125 /* if it does not need or is spilt
1126 or is already assigned to registers
1127 or will not live beyond this instructions */
1130 bitVectBitValue (_G.regAssigned, sym->key) ||
1131 sym->liveTo <= ic->seq)
1134 /* if some liverange has been spilt at the block level
1135 and this one live beyond this block then spil this
1137 if (_G.blockSpil && sym->liveTo > ebbs[i]->lSeq)
1142 /* if trying to allocate this will cause
1143 a spill and there is nothing to spill
1144 or this one is rematerializable then
1146 willCS = willCauseSpill (sym->nRegs, sym->regType);
1147 spillable = computeSpillable (ic);
1149 (willCS && bitVectIsZero (spillable)))
1157 /* if it has a spillocation & is used less than
1158 all other live ranges then spill this */
1160 if (sym->usl.spillLoc) {
1161 symbol *leastUsed = leastUsedLR (liveRangesWith (spillable,
1162 allLRs, ebbs[i], ic));
1163 if (leastUsed && leastUsed->used > sym->used) {
1168 /* if none of the liveRanges have a spillLocation then better
1169 to spill this one than anything else already assigned to registers */
1170 if (liveRangesWith(spillable,noSpilLoc,ebbs[i],ic)) {
1177 /* if we need ptr regs for the right side
1179 if (POINTER_GET (ic) && IS_SYMOP (IC_LEFT (ic))
1180 && getSize (OP_SYMBOL (IC_LEFT (ic))->type)
1181 <= (unsigned) PTRSIZE)
1186 /* else we assign registers to it */
1187 _G.regAssigned = bitVectSetBit (_G.regAssigned, sym->key);
1189 for (j = 0; j < sym->nRegs; j++)
1191 if (sym->regType == REG_PTR)
1192 sym->regs[j] = getRegPtr (ic, ebbs[i], sym);
1194 sym->regs[j] = getRegGpr (ic, ebbs[i], sym);
1196 /* if the allocation falied which means
1197 this was spilt then break */
1201 /* if it shares registers with operands make sure
1202 that they are in the same position */
1203 if (IC_LEFT (ic) && IS_SYMOP (IC_LEFT (ic)) &&
1204 OP_SYMBOL (IC_LEFT (ic))->nRegs && ic->op != '=')
1205 positionRegs (OP_SYMBOL (IC_RESULT (ic)),
1206 OP_SYMBOL (IC_LEFT (ic)), ic->lineno);
1207 /* do the same for the right operand */
1208 if (IC_RIGHT (ic) && IS_SYMOP (IC_RIGHT (ic)) &&
1209 OP_SYMBOL (IC_RIGHT (ic))->nRegs)
1210 positionRegs (OP_SYMBOL (IC_RESULT (ic)),
1211 OP_SYMBOL (IC_RIGHT (ic)), ic->lineno);
1224 /*-----------------------------------------------------------------*/
1225 /* rUmaskForOp :- returns register mask for an operand */
1226 /*-----------------------------------------------------------------*/
1228 rUmaskForOp (operand * op)
1234 /* only temporaries are assigned registers */
1238 sym = OP_SYMBOL (op);
1240 /* if spilt or no registers assigned to it
1242 if (sym->isspilt || !sym->nRegs)
1245 rumask = newBitVect (ds390_nRegs);
1247 for (j = 0; j < sym->nRegs; j++)
1249 rumask = bitVectSetBit (rumask,
1250 sym->regs[j]->rIdx);
1256 /*-----------------------------------------------------------------*/
1257 /* regsUsedIniCode :- returns bit vector of registers used in iCode */
1258 /*-----------------------------------------------------------------*/
1260 regsUsedIniCode (iCode * ic)
1262 bitVect *rmask = newBitVect (ds390_nRegs);
1264 /* do the special cases first */
1267 rmask = bitVectUnion (rmask,
1268 rUmaskForOp (IC_COND (ic)));
1272 /* for the jumptable */
1273 if (ic->op == JUMPTABLE)
1275 rmask = bitVectUnion (rmask,
1276 rUmaskForOp (IC_JTCOND (ic)));
1281 /* of all other cases */
1283 rmask = bitVectUnion (rmask,
1284 rUmaskForOp (IC_LEFT (ic)));
1288 rmask = bitVectUnion (rmask,
1289 rUmaskForOp (IC_RIGHT (ic)));
1292 rmask = bitVectUnion (rmask,
1293 rUmaskForOp (IC_RESULT (ic)));
1299 /*-----------------------------------------------------------------*/
1300 /* createRegMask - for each instruction will determine the regsUsed */
1301 /*-----------------------------------------------------------------*/
1303 createRegMask (eBBlock ** ebbs, int count)
1307 /* for all blocks */
1308 for (i = 0; i < count; i++)
1312 if (ebbs[i]->noPath &&
1313 (ebbs[i]->entryLabel != entryLabel &&
1314 ebbs[i]->entryLabel != returnLabel))
1317 /* for all instructions */
1318 for (ic = ebbs[i]->sch; ic; ic = ic->next)
1323 if (SKIP_IC2 (ic) || !ic->rlive)
1326 /* first mark the registers used in this
1328 ic->rUsed = regsUsedIniCode (ic);
1329 _G.funcrUsed = bitVectUnion (_G.funcrUsed, ic->rUsed);
1331 /* now create the register mask for those
1332 registers that are in use : this is a
1333 super set of ic->rUsed */
1334 ic->rMask = newBitVect (ds390_nRegs + 1);
1336 /* for all live Ranges alive at this point */
1337 for (j = 1; j < ic->rlive->size; j++)
1342 /* if not alive then continue */
1343 if (!bitVectBitValue (ic->rlive, j))
1346 /* find the live range we are interested in */
1347 if (!(sym = hTabItemWithKey (liveRanges, j)))
1349 werror (E_INTERNAL_ERROR, __FILE__, __LINE__,
1350 "createRegMask cannot find live range");
1354 /* if no register assigned to it */
1355 if (!sym->nRegs || sym->isspilt)
1358 /* for all the registers allocated to it */
1359 for (k = 0; k < sym->nRegs; k++)
1362 bitVectSetBit (ic->rMask, sym->regs[k]->rIdx);
1368 /*-----------------------------------------------------------------*/
1369 /* rematStr - returns the rematerialized string for a remat var */
1370 /*-----------------------------------------------------------------*/
1372 rematStr (symbol * sym)
1375 iCode *ic = sym->rematiCode;
1380 /* if plus or minus print the right hand side */
1381 if (ic->op == '+' || ic->op == '-')
1383 sprintf (s, "0x%04x %c ", (int) operandLitValue (IC_RIGHT (ic)),
1386 ic = OP_SYMBOL (IC_LEFT (ic))->rematiCode;
1390 /* we reached the end */
1391 sprintf (s, "%s", OP_SYMBOL (IC_LEFT (ic))->rname);
1398 /*-----------------------------------------------------------------*/
1399 /* regTypeNum - computes the type & number of registers required */
1400 /*-----------------------------------------------------------------*/
1408 /* for each live range do */
1409 for (sym = hTabFirstItem (liveRanges, &k); sym;
1410 sym = hTabNextItem (liveRanges, &k))
1413 /* if used zero times then no registers needed */
1414 if ((sym->liveTo - sym->liveFrom) == 0)
1418 /* if the live range is a temporary */
1422 /* if the type is marked as a conditional */
1423 if (sym->regType == REG_CND)
1426 /* if used in return only then we don't
1428 if (sym->ruonly || sym->accuse)
1430 if (IS_AGGREGATE (sym->type) || sym->isptr)
1431 sym->type = aggrToPtr (sym->type, FALSE);
1435 /* if the symbol has only one definition &
1436 that definition is a get_pointer and the
1437 pointer we are getting is rematerializable and
1440 if (bitVectnBitsOn (sym->defs) == 1 &&
1441 (ic = hTabItemWithKey (iCodehTab,
1442 bitVectFirstBit (sym->defs))) &&
1445 !IS_BITVAR (sym->etype))
1449 /* if remat in data space */
1450 if (OP_SYMBOL (IC_LEFT (ic))->remat &&
1452 DCL_TYPE (aggrToPtr (sym->type, FALSE)) == POINTER)
1455 /* create a psuedo symbol & force a spil */
1456 symbol *psym = newSymbol (rematStr (OP_SYMBOL (IC_LEFT (ic))), 1);
1457 psym->type = sym->type;
1458 psym->etype = sym->etype;
1459 strcpy (psym->rname, psym->name);
1461 sym->usl.spillLoc = psym;
1465 /* if in data space or idata space then try to
1466 allocate pointer register */
1470 /* if not then we require registers */
1471 sym->nRegs = ((IS_AGGREGATE (sym->type) || sym->isptr) ?
1472 getSize (sym->type = aggrToPtr (sym->type, FALSE)) :
1473 getSize (sym->type));
1477 fprintf (stderr, "allocated more than 4 or 0 registers for type ");
1478 printTypeChain (sym->type, stderr);
1479 fprintf (stderr, "\n");
1482 /* determine the type of register required */
1483 if (sym->nRegs == 1 &&
1484 IS_PTR (sym->type) &&
1486 sym->regType = REG_PTR;
1488 sym->regType = REG_GPR;
1492 /* for the first run we don't provide */
1493 /* registers for true symbols we will */
1494 /* see how things go */
1500 /*-----------------------------------------------------------------*/
1501 /* freeAllRegs - mark all registers as free */
1502 /*-----------------------------------------------------------------*/
1508 for (i = 0; i < ds390_nRegs; i++)
1509 regs390[i].isFree = 1;
1512 /*-----------------------------------------------------------------*/
1513 /* deallocStackSpil - this will set the stack pointer back */
1514 /*-----------------------------------------------------------------*/
1516 DEFSETFUNC (deallocStackSpil)
1524 /*-----------------------------------------------------------------*/
1525 /* farSpacePackable - returns the packable icode for far variables */
1526 /*-----------------------------------------------------------------*/
1528 farSpacePackable (iCode * ic)
1532 /* go thru till we find a definition for the
1533 symbol on the right */
1534 for (dic = ic->prev; dic; dic = dic->prev)
1537 /* if the definition is a call then no */
1538 if ((dic->op == CALL || dic->op == PCALL) &&
1539 IC_RESULT (dic)->key == IC_RIGHT (ic)->key)
1544 /* if shift by unknown amount then not */
1545 if ((dic->op == LEFT_OP || dic->op == RIGHT_OP) &&
1546 IC_RESULT (dic)->key == IC_RIGHT (ic)->key)
1549 /* if pointer get and size > 1 */
1550 if (POINTER_GET (dic) &&
1551 getSize (aggrToPtr (operandType (IC_LEFT (dic)), FALSE)) > 1)
1554 if (POINTER_SET (dic) &&
1555 getSize (aggrToPtr (operandType (IC_RESULT (dic)), FALSE)) > 1)
1558 /* if any three is a true symbol in far space */
1559 if (IC_RESULT (dic) &&
1560 IS_TRUE_SYMOP (IC_RESULT (dic)) &&
1561 isOperandInFarSpace (IC_RESULT (dic)))
1564 if (IC_RIGHT (dic) &&
1565 IS_TRUE_SYMOP (IC_RIGHT (dic)) &&
1566 isOperandInFarSpace (IC_RIGHT (dic)) &&
1567 !isOperandEqual (IC_RIGHT (dic), IC_RESULT (ic)))
1570 if (IC_LEFT (dic) &&
1571 IS_TRUE_SYMOP (IC_LEFT (dic)) &&
1572 isOperandInFarSpace (IC_LEFT (dic)) &&
1573 !isOperandEqual (IC_LEFT (dic), IC_RESULT (ic)))
1576 if (isOperandEqual (IC_RIGHT (ic), IC_RESULT (dic)))
1578 if ((dic->op == LEFT_OP ||
1579 dic->op == RIGHT_OP ||
1581 IS_OP_LITERAL (IC_RIGHT (dic)))
1591 /*-----------------------------------------------------------------*/
1592 /* packRegsForAssign - register reduction for assignment */
1593 /*-----------------------------------------------------------------*/
1595 packRegsForAssign (iCode * ic, eBBlock * ebp)
1599 if (!IS_ITEMP (IC_RIGHT (ic)) ||
1600 OP_SYMBOL (IC_RIGHT (ic))->isind ||
1601 OP_LIVETO (IC_RIGHT (ic)) > ic->seq)
1606 /* if the true symbol is defined in far space or on stack
1607 then we should not since this will increase register pressure */
1609 if (isOperandInFarSpace (IC_RESULT (ic)))
1611 if ((dic = farSpacePackable (ic)))
1617 if (isOperandInFarSpace(IC_RESULT(ic)) && !farSpacePackable(ic)) {
1622 /* find the definition of iTempNN scanning backwards if we find a
1623 a use of the true symbol in before we find the definition then
1625 for (dic = ic->prev; dic; dic = dic->prev)
1627 /* if there is a function call then don't pack it */
1628 if ((dic->op == CALL || dic->op == PCALL))
1637 if (IS_TRUE_SYMOP (IC_RESULT (dic)) &&
1638 IS_OP_VOLATILE (IC_RESULT (dic)))
1644 if (IS_SYMOP (IC_RESULT (dic)) &&
1645 IC_RESULT (dic)->key == IC_RIGHT (ic)->key)
1647 if (POINTER_SET (dic))
1653 if (IS_SYMOP (IC_RIGHT (dic)) &&
1654 (IC_RIGHT (dic)->key == IC_RESULT (ic)->key ||
1655 IC_RIGHT (dic)->key == IC_RIGHT (ic)->key))
1661 if (IS_SYMOP (IC_LEFT (dic)) &&
1662 (IC_LEFT (dic)->key == IC_RESULT (ic)->key ||
1663 IC_LEFT (dic)->key == IC_RIGHT (ic)->key))
1669 if (POINTER_SET (dic) &&
1670 IC_RESULT (dic)->key == IC_RESULT (ic)->key)
1678 return 0; /* did not find */
1680 /* if the result is on stack or iaccess then it must be
1681 the same atleast one of the operands */
1682 if (OP_SYMBOL (IC_RESULT (ic))->onStack ||
1683 OP_SYMBOL (IC_RESULT (ic))->iaccess)
1686 /* the operation has only one symbol
1687 operator then we can pack */
1688 if ((IC_LEFT (dic) && !IS_SYMOP (IC_LEFT (dic))) ||
1689 (IC_RIGHT (dic) && !IS_SYMOP (IC_RIGHT (dic))))
1692 if (!((IC_LEFT (dic) &&
1693 IC_RESULT (ic)->key == IC_LEFT (dic)->key) ||
1695 IC_RESULT (ic)->key == IC_RIGHT (dic)->key)))
1699 /* found the definition */
1700 /* replace the result with the result of */
1701 /* this assignment and remove this assignment */
1702 IC_RESULT (dic) = IC_RESULT (ic);
1704 if (IS_ITEMP (IC_RESULT (dic)) && OP_SYMBOL (IC_RESULT (dic))->liveFrom > dic->seq)
1706 OP_SYMBOL (IC_RESULT (dic))->liveFrom = dic->seq;
1708 /* delete from liverange table also
1709 delete from all the points inbetween and the new
1711 for (sic = dic; sic != ic; sic = sic->next)
1713 bitVectUnSetBit (sic->rlive, IC_RESULT (ic)->key);
1714 if (IS_ITEMP (IC_RESULT (dic)))
1715 bitVectSetBit (sic->rlive, IC_RESULT (dic)->key);
1718 remiCodeFromeBBlock (ebp, ic);
1719 hTabDeleteItem (&iCodehTab, ic->key, ic, DELETE_ITEM, NULL);
1720 OP_DEFS (IC_RESULT (dic)) = bitVectSetBit (OP_DEFS (IC_RESULT (dic)), dic->key);
1725 /*-----------------------------------------------------------------*/
1726 /* findAssignToSym : scanning backwards looks for first assig found */
1727 /*-----------------------------------------------------------------*/
1729 findAssignToSym (operand * op, iCode * ic)
1733 for (dic = ic->prev; dic; dic = dic->prev)
1736 /* if definition by assignment */
1737 if (dic->op == '=' &&
1738 !POINTER_SET (dic) &&
1739 IC_RESULT (dic)->key == op->key
1740 /* && IS_TRUE_SYMOP(IC_RIGHT(dic)) */
1744 /* we are interested only if defined in far space */
1745 /* or in stack space in case of + & - */
1747 /* if assigned to a non-symbol then return
1749 if (!IS_SYMOP (IC_RIGHT (dic)))
1752 /* if the symbol is in far space then
1754 if (isOperandInFarSpace (IC_RIGHT (dic)))
1757 /* for + & - operations make sure that
1758 if it is on the stack it is the same
1759 as one of the three operands */
1760 if ((ic->op == '+' || ic->op == '-') &&
1761 OP_SYMBOL (IC_RIGHT (dic))->onStack)
1764 if (IC_RESULT (ic)->key != IC_RIGHT (dic)->key &&
1765 IC_LEFT (ic)->key != IC_RIGHT (dic)->key &&
1766 IC_RIGHT (ic)->key != IC_RIGHT (dic)->key)
1774 /* if we find an usage then we cannot delete it */
1775 if (IC_LEFT (dic) && IC_LEFT (dic)->key == op->key)
1778 if (IC_RIGHT (dic) && IC_RIGHT (dic)->key == op->key)
1781 if (POINTER_SET (dic) && IC_RESULT (dic)->key == op->key)
1785 /* now make sure that the right side of dic
1786 is not defined between ic & dic */
1789 iCode *sic = dic->next;
1791 for (; sic != ic; sic = sic->next)
1792 if (IC_RESULT (sic) &&
1793 IC_RESULT (sic)->key == IC_RIGHT (dic)->key)
1802 /*-----------------------------------------------------------------*/
1803 /* packRegsForSupport :- reduce some registers for support calls */
1804 /*-----------------------------------------------------------------*/
1806 packRegsForSupport (iCode * ic, eBBlock * ebp)
1809 /* for the left & right operand :- look to see if the
1810 left was assigned a true symbol in far space in that
1811 case replace them */
1812 if (IS_ITEMP (IC_LEFT (ic)) &&
1813 OP_SYMBOL (IC_LEFT (ic))->liveTo <= ic->seq)
1815 iCode *dic = findAssignToSym (IC_LEFT (ic), ic);
1821 /* found it we need to remove it from the
1823 for (sic = dic; sic != ic; sic = sic->next)
1824 bitVectUnSetBit (sic->rlive, IC_LEFT (ic)->key);
1826 IC_LEFT (ic)->operand.symOperand =
1827 IC_RIGHT (dic)->operand.symOperand;
1828 IC_LEFT (ic)->key = IC_RIGHT (dic)->operand.symOperand->key;
1829 remiCodeFromeBBlock (ebp, dic);
1830 hTabDeleteItem (&iCodehTab, dic->key, dic, DELETE_ITEM, NULL);
1834 /* do the same for the right operand */
1837 IS_ITEMP (IC_RIGHT (ic)) &&
1838 OP_SYMBOL (IC_RIGHT (ic))->liveTo <= ic->seq)
1840 iCode *dic = findAssignToSym (IC_RIGHT (ic), ic);
1846 /* if this is a subtraction & the result
1847 is a true symbol in far space then don't pack */
1848 if (ic->op == '-' && IS_TRUE_SYMOP (IC_RESULT (dic)))
1850 sym_link *etype = getSpec (operandType (IC_RESULT (dic)));
1851 if (IN_FARSPACE (SPEC_OCLS (etype)))
1854 /* found it we need to remove it from the
1856 for (sic = dic; sic != ic; sic = sic->next)
1857 bitVectUnSetBit (sic->rlive, IC_RIGHT (ic)->key);
1859 IC_RIGHT (ic)->operand.symOperand =
1860 IC_RIGHT (dic)->operand.symOperand;
1861 IC_RIGHT (ic)->key = IC_RIGHT (dic)->operand.symOperand->key;
1863 remiCodeFromeBBlock (ebp, dic);
1864 hTabDeleteItem (&iCodehTab, dic->key, dic, DELETE_ITEM, NULL);
1871 #define IS_OP_RUONLY(x) (x && IS_SYMOP(x) && OP_SYMBOL(x)->ruonly)
1874 /*-----------------------------------------------------------------*/
1875 /* packRegsForOneuse : - will reduce some registers for single Use */
1876 /*-----------------------------------------------------------------*/
1878 packRegsForOneuse (iCode * ic, operand * op, eBBlock * ebp)
1882 /* I can't figure out how to make this safe yet. */
1883 if ((int)ic+(int)op+(int)ebp) {
1894 /* if returning a literal then do nothing */
1898 /* only upto 2 bytes since we cannot predict
1899 the usage of b, & acc */
1900 if (getSize (operandType (op)) > (fReturnSizeDS390 - 2) &&
1903 !POINTER_SET (ic) &&
1907 /* this routine will mark the a symbol as used in one
1908 instruction use only && if the defintion is local
1909 (ie. within the basic block) && has only one definition &&
1910 that definiion is either a return value from a
1911 function or does not contain any variables in
1913 uses = bitVectCopy (OP_USES (op));
1914 bitVectUnSetBit (uses, ic->key); /* take away this iCode */
1915 if (!bitVectIsZero (uses)) /* has other uses */
1918 /* if it has only one defintion */
1919 if (bitVectnBitsOn (OP_DEFS (op)) > 1)
1920 return NULL; /* has more than one definition */
1922 /* get the that definition */
1924 hTabItemWithKey (iCodehTab,
1925 bitVectFirstBit (OP_DEFS (op)))))
1928 /* if that only usage is a cast */
1929 if (dic->op == CAST) {
1930 /* to a bigger type */
1931 if (getSize(OP_SYM_TYPE(IC_RESULT(dic))) >
1932 getSize(OP_SYM_TYPE(IC_RIGHT(dic)))) {
1933 /* than we can not, since we cannot predict the usage of b & acc */
1938 /* found the definition now check if it is local */
1939 if (dic->seq < ebp->fSeq ||
1940 dic->seq > ebp->lSeq)
1941 return NULL; /* non-local */
1943 /* now check if it is the return from
1945 if (dic->op == CALL || dic->op == PCALL)
1947 if (ic->op != SEND && ic->op != RETURN)
1949 OP_SYMBOL (op)->ruonly = 1;
1956 /* otherwise check that the definition does
1957 not contain any symbols in far space */
1958 if (isOperandInFarSpace (IC_LEFT (dic)) ||
1959 isOperandInFarSpace (IC_RIGHT (dic)) ||
1960 IS_OP_RUONLY (IC_LEFT (ic)) ||
1961 IS_OP_RUONLY (IC_RIGHT (ic)))
1966 /* if pointer set then make sure the pointer
1968 if (POINTER_SET (dic) &&
1969 !IS_DATA_PTR (aggrToPtr (operandType (IC_RESULT (dic)), FALSE)))
1972 if (POINTER_GET (dic) &&
1973 !IS_DATA_PTR (aggrToPtr (operandType (IC_LEFT (dic)), FALSE)))
1978 /* also make sure the intervenening instructions
1979 don't have any thing in far space */
1980 for (dic = dic->next; dic && dic != ic; dic = dic->next)
1983 /* if there is an intervening function call then no */
1984 if (dic->op == CALL || dic->op == PCALL)
1986 /* if pointer set then make sure the pointer
1988 if (POINTER_SET (dic) &&
1989 !IS_DATA_PTR (aggrToPtr (operandType (IC_RESULT (dic)), FALSE)))
1992 if (POINTER_GET (dic) &&
1993 !IS_DATA_PTR (aggrToPtr (operandType (IC_LEFT (dic)), FALSE)))
1996 /* if address of & the result is remat the okay */
1997 if (dic->op == ADDRESS_OF &&
1998 OP_SYMBOL (IC_RESULT (dic))->remat)
2001 /* if operand has size of three or more & this
2002 operation is a '*','/' or '%' then 'b' may
2004 if ((dic->op == '%' || dic->op == '/' || dic->op == '*') &&
2005 getSize (operandType (op)) >= 3)
2008 /* if left or right or result is in far space */
2009 if (isOperandInFarSpace (IC_LEFT (dic)) ||
2010 isOperandInFarSpace (IC_RIGHT (dic)) ||
2011 isOperandInFarSpace (IC_RESULT (dic)) ||
2012 IS_OP_RUONLY (IC_LEFT (dic)) ||
2013 IS_OP_RUONLY (IC_RIGHT (dic)) ||
2014 IS_OP_RUONLY (IC_RESULT (dic)))
2020 OP_SYMBOL (op)->ruonly = 1;
2025 /*-----------------------------------------------------------------*/
2026 /* isBitwiseOptimizable - requirements of JEAN LOUIS VERN */
2027 /*-----------------------------------------------------------------*/
2029 isBitwiseOptimizable (iCode * ic)
2031 sym_link *ltype = getSpec (operandType (IC_LEFT (ic)));
2032 sym_link *rtype = getSpec (operandType (IC_RIGHT (ic)));
2034 /* bitwise operations are considered optimizable
2035 under the following conditions (Jean-Louis VERN)
2047 if ( IS_LITERAL (rtype) ||
2048 (IS_BITVAR (ltype) && IN_BITSPACE (SPEC_OCLS (ltype))))
2054 /*-----------------------------------------------------------------*/
2055 /* packRegsForAccUse - pack registers for acc use */
2056 /*-----------------------------------------------------------------*/
2058 packRegsForAccUse (iCode * ic)
2062 /* if + or - then it has to be one byte result */
2063 if ((ic->op == '+' || ic->op == '-')
2064 && getSize (operandType (IC_RESULT (ic))) > 1)
2067 /* if shift operation make sure right side is not a literal */
2068 if (ic->op == RIGHT_OP &&
2069 (isOperandLiteral (IC_RIGHT (ic)) ||
2070 getSize (operandType (IC_RESULT (ic))) > 1))
2073 if (ic->op == LEFT_OP &&
2074 (isOperandLiteral (IC_RIGHT (ic)) ||
2075 getSize (operandType (IC_RESULT (ic))) > 1))
2078 if (IS_BITWISE_OP (ic) &&
2079 getSize (operandType (IC_RESULT (ic))) > 1)
2083 /* has only one definition */
2084 if (bitVectnBitsOn (OP_DEFS (IC_RESULT (ic))) > 1)
2087 /* has only one use */
2088 if (bitVectnBitsOn (OP_USES (IC_RESULT (ic))) > 1)
2091 /* and the usage immediately follows this iCode */
2092 if (!(uic = hTabItemWithKey (iCodehTab,
2093 bitVectFirstBit (OP_USES (IC_RESULT (ic))))))
2096 if (ic->next != uic)
2099 /* if it is a conditional branch then we definitely can */
2103 if (uic->op == JUMPTABLE)
2106 /* if the usage is not is an assignment
2107 or an arithmetic / bitwise / shift operation then not */
2108 if (POINTER_SET (uic) &&
2109 getSize (aggrToPtr (operandType (IC_RESULT (uic)), FALSE)) > 1)
2112 if (uic->op != '=' &&
2113 !IS_ARITHMETIC_OP (uic) &&
2114 !IS_BITWISE_OP (uic) &&
2115 uic->op != LEFT_OP &&
2116 uic->op != RIGHT_OP)
2119 /* if used in ^ operation then make sure right is not a
2121 if (uic->op == '^' && isOperandLiteral (IC_RIGHT (uic)))
2124 /* if shift operation make sure right side is not a literal */
2125 if (uic->op == RIGHT_OP &&
2126 (isOperandLiteral (IC_RIGHT (uic)) ||
2127 getSize (operandType (IC_RESULT (uic))) > 1))
2130 if (uic->op == LEFT_OP &&
2131 (isOperandLiteral (IC_RIGHT (uic)) ||
2132 getSize (operandType (IC_RESULT (uic))) > 1))
2135 /* make sure that the result of this icode is not on the
2136 stack, since acc is used to compute stack offset */
2137 if (IS_TRUE_SYMOP (IC_RESULT (uic)) &&
2138 OP_SYMBOL (IC_RESULT (uic))->onStack)
2141 /* if either one of them in far space then we cannot */
2142 if ((IS_TRUE_SYMOP (IC_LEFT (uic)) &&
2143 isOperandInFarSpace (IC_LEFT (uic))) ||
2144 (IS_TRUE_SYMOP (IC_RIGHT (uic)) &&
2145 isOperandInFarSpace (IC_RIGHT (uic))))
2148 /* if the usage has only one operand then we can */
2149 if (IC_LEFT (uic) == NULL ||
2150 IC_RIGHT (uic) == NULL)
2153 /* make sure this is on the left side if not
2154 a '+' since '+' is commutative */
2155 if (ic->op != '+' &&
2156 IC_LEFT (uic)->key != IC_RESULT (ic)->key)
2160 // this is too dangerous and need further restrictions
2163 /* if one of them is a literal then we can */
2164 if ((IC_LEFT (uic) && IS_OP_LITERAL (IC_LEFT (uic))) ||
2165 (IC_RIGHT (uic) && IS_OP_LITERAL (IC_RIGHT (uic))))
2167 OP_SYMBOL (IC_RESULT (ic))->accuse = 1;
2172 /* if the other one is not on stack then we can */
2173 if (IC_LEFT (uic)->key == IC_RESULT (ic)->key &&
2174 (IS_ITEMP (IC_RIGHT (uic)) ||
2175 (IS_TRUE_SYMOP (IC_RIGHT (uic)) &&
2176 !OP_SYMBOL (IC_RIGHT (uic))->onStack)))
2179 if (IC_RIGHT (uic)->key == IC_RESULT (ic)->key &&
2180 (IS_ITEMP (IC_LEFT (uic)) ||
2181 (IS_TRUE_SYMOP (IC_LEFT (uic)) &&
2182 !OP_SYMBOL (IC_LEFT (uic))->onStack)))
2188 OP_SYMBOL (IC_RESULT (ic))->accuse = 1;
2193 /*-----------------------------------------------------------------*/
2194 /* packForPush - hueristics to reduce iCode for pushing */
2195 /*-----------------------------------------------------------------*/
2197 packForPush (iCode * ic, eBBlock * ebp)
2202 if (ic->op != IPUSH || !IS_ITEMP (IC_LEFT (ic)))
2205 /* must have only definition & one usage */
2206 if (bitVectnBitsOn (OP_DEFS (IC_LEFT (ic))) != 1 ||
2207 bitVectnBitsOn (OP_USES (IC_LEFT (ic))) != 1)
2210 /* find the definition */
2211 if (!(dic = hTabItemWithKey (iCodehTab,
2212 bitVectFirstBit (OP_DEFS (IC_LEFT (ic))))))
2215 if (dic->op != '=' || POINTER_SET (dic))
2218 /* make sure the right side does not have any definitions
2220 dbv = OP_DEFS(IC_RIGHT(dic));
2221 for (lic = ic; lic && lic != dic ; lic = lic->prev) {
2222 if (bitVectBitValue(dbv,lic->key)) return ;
2224 /* make sure they have the same type */
2226 sym_link *itype=operandType(IC_LEFT(ic));
2227 sym_link *ditype=operandType(IC_RIGHT(dic));
2229 if (SPEC_USIGN(itype)!=SPEC_USIGN(ditype) ||
2230 SPEC_LONG(itype)!=SPEC_LONG(ditype))
2233 /* extend the live range of replaced operand if needed */
2234 if (OP_SYMBOL(IC_RIGHT(dic))->liveTo < ic->seq) {
2235 OP_SYMBOL(IC_RIGHT(dic))->liveTo = ic->seq;
2237 /* we now we know that it has one & only one def & use
2238 and the that the definition is an assignment */
2239 IC_LEFT (ic) = IC_RIGHT (dic);
2241 remiCodeFromeBBlock (ebp, dic);
2242 hTabDeleteItem (&iCodehTab, dic->key, dic, DELETE_ITEM, NULL);
2245 /*-----------------------------------------------------------------*/
2246 /* packRegisters - does some transformations to reduce register */
2248 /*-----------------------------------------------------------------*/
2250 packRegisters (eBBlock * ebp)
2260 /* look for assignments of the form */
2261 /* iTempNN = TRueSym (someoperation) SomeOperand */
2263 /* TrueSym := iTempNN:1 */
2264 for (ic = ebp->sch; ic; ic = ic->next)
2268 /* find assignment of the form TrueSym := iTempNN:1 */
2269 if (ic->op == '=' && !POINTER_SET (ic))
2270 change += packRegsForAssign (ic, ebp);
2277 for (ic = ebp->sch; ic; ic = ic->next)
2280 /* if this is an itemp & result of a address of a true sym
2281 then mark this as rematerialisable */
2282 if (ic->op == ADDRESS_OF &&
2283 IS_ITEMP (IC_RESULT (ic)) &&
2284 IS_TRUE_SYMOP (IC_LEFT (ic)) &&
2285 bitVectnBitsOn (OP_DEFS (IC_RESULT (ic))) == 1 &&
2286 !OP_SYMBOL (IC_LEFT (ic))->onStack)
2289 OP_SYMBOL (IC_RESULT (ic))->remat = 1;
2290 OP_SYMBOL (IC_RESULT (ic))->rematiCode = ic;
2291 OP_SYMBOL (IC_RESULT (ic))->usl.spillLoc = NULL;
2295 /* if straight assignment then carry remat flag if
2296 this is the only definition */
2297 if (ic->op == '=' &&
2298 !POINTER_SET (ic) &&
2299 IS_SYMOP (IC_RIGHT (ic)) &&
2300 OP_SYMBOL (IC_RIGHT (ic))->remat &&
2301 bitVectnBitsOn (OP_SYMBOL (IC_RESULT (ic))->defs) <= 1)
2304 OP_SYMBOL (IC_RESULT (ic))->remat =
2305 OP_SYMBOL (IC_RIGHT (ic))->remat;
2306 OP_SYMBOL (IC_RESULT (ic))->rematiCode =
2307 OP_SYMBOL (IC_RIGHT (ic))->rematiCode;
2310 /* if this is a +/- operation with a rematerizable
2311 then mark this as rematerializable as well */
2312 if ((ic->op == '+' || ic->op == '-') &&
2313 (IS_SYMOP (IC_LEFT (ic)) &&
2314 IS_ITEMP (IC_RESULT (ic)) &&
2315 OP_SYMBOL (IC_LEFT (ic))->remat &&
2316 bitVectnBitsOn (OP_DEFS (IC_RESULT (ic))) == 1 &&
2317 IS_OP_LITERAL (IC_RIGHT (ic))))
2320 //int i = operandLitValue(IC_RIGHT(ic));
2321 OP_SYMBOL (IC_RESULT (ic))->remat = 1;
2322 OP_SYMBOL (IC_RESULT (ic))->rematiCode = ic;
2323 OP_SYMBOL (IC_RESULT (ic))->usl.spillLoc = NULL;
2326 /* mark the pointer usages */
2327 if (POINTER_SET (ic))
2328 OP_SYMBOL (IC_RESULT (ic))->uptr = 1;
2330 if (POINTER_GET (ic))
2331 OP_SYMBOL (IC_LEFT (ic))->uptr = 1;
2335 /* if we are using a symbol on the stack
2336 then we should say ds390_ptrRegReq */
2337 if (ic->op == IFX && IS_SYMOP (IC_COND (ic)))
2338 ds390_ptrRegReq += ((OP_SYMBOL (IC_COND (ic))->onStack ? !options.stack10bit : 0) +
2339 OP_SYMBOL (IC_COND (ic))->iaccess);
2340 else if (ic->op == JUMPTABLE && IS_SYMOP (IC_JTCOND (ic)))
2341 ds390_ptrRegReq += ((OP_SYMBOL (IC_JTCOND (ic))->onStack ? !options.stack10bit : 0) +
2342 OP_SYMBOL (IC_JTCOND (ic))->iaccess);
2345 if (IS_SYMOP (IC_LEFT (ic)))
2346 ds390_ptrRegReq += ((OP_SYMBOL (IC_LEFT (ic))->onStack ? !options.stack10bit : 0) +
2347 OP_SYMBOL (IC_LEFT (ic))->iaccess);
2348 if (IS_SYMOP (IC_RIGHT (ic)))
2349 ds390_ptrRegReq += ((OP_SYMBOL (IC_RIGHT (ic))->onStack ? !options.stack10bit : 0) +
2350 OP_SYMBOL (IC_RIGHT (ic))->iaccess);
2351 if (IS_SYMOP (IC_RESULT (ic)))
2352 ds390_ptrRegReq += ((OP_SYMBOL (IC_RESULT (ic))->onStack ? !options.stack10bit : 0) +
2353 OP_SYMBOL (IC_RESULT (ic))->iaccess);
2358 /* if the condition of an if instruction
2359 is defined in the previous instruction then
2360 mark the itemp as a conditional */
2361 if ((IS_CONDITIONAL (ic) ||
2362 (IS_BITWISE_OP(ic) && isBitwiseOptimizable(ic))) &&
2363 ic->next && ic->next->op == IFX &&
2364 isOperandEqual (IC_RESULT (ic), IC_COND (ic->next)) &&
2365 OP_SYMBOL (IC_RESULT (ic))->liveTo <= ic->next->seq)
2368 OP_SYMBOL (IC_RESULT (ic))->regType = REG_CND;
2372 /* if the condition of an if instruction
2373 is defined in the previous instruction and
2374 this is the only usage then
2375 mark the itemp as a conditional */
2376 if ((IS_CONDITIONAL (ic) ||
2377 (IS_BITWISE_OP(ic) && isBitwiseOptimizable (ic))) &&
2378 ic->next && ic->next->op == IFX &&
2379 bitVectnBitsOn (OP_USES(IC_RESULT(ic)))==1 &&
2380 isOperandEqual (IC_RESULT (ic), IC_COND (ic->next)) &&
2381 OP_SYMBOL (IC_RESULT (ic))->liveTo <= ic->next->seq)
2383 OP_SYMBOL (IC_RESULT (ic))->regType = REG_CND;
2388 /* reduce for support function calls */
2389 if (ic->supportRtn || ic->op == '+' || ic->op == '-')
2390 packRegsForSupport (ic, ebp);
2392 /* some cases the redundant moves can
2393 can be eliminated for return statements */
2394 if ((ic->op == RETURN || ic->op == SEND) &&
2395 !isOperandInFarSpace (IC_LEFT (ic)) &&
2397 packRegsForOneuse (ic, IC_LEFT (ic), ebp);
2399 /* if pointer set & left has a size more than
2400 one and right is not in far space */
2401 if (POINTER_SET (ic) &&
2402 !isOperandInFarSpace (IC_RIGHT (ic)) &&
2403 !OP_SYMBOL (IC_RESULT (ic))->remat &&
2404 !IS_OP_RUONLY (IC_RIGHT (ic)) &&
2405 getSize (aggrToPtr (operandType (IC_RESULT (ic)), FALSE)) > 1)
2407 packRegsForOneuse (ic, IC_RESULT (ic), ebp);
2409 /* if pointer get */
2410 if (POINTER_GET (ic) &&
2411 !isOperandInFarSpace (IC_RESULT (ic)) &&
2412 !OP_SYMBOL (IC_LEFT (ic))->remat &&
2413 !IS_OP_RUONLY (IC_RESULT (ic)) &&
2414 getSize (aggrToPtr (operandType (IC_LEFT (ic)), FALSE)) > 1)
2416 packRegsForOneuse (ic, IC_LEFT (ic), ebp);
2419 /* if this is cast for intergral promotion then
2420 check if only use of the definition of the
2421 operand being casted/ if yes then replace
2422 the result of that arithmetic operation with
2423 this result and get rid of the cast */
2426 sym_link *fromType = operandType (IC_RIGHT (ic));
2427 sym_link *toType = operandType (IC_LEFT (ic));
2429 if (IS_INTEGRAL (fromType) && IS_INTEGRAL (toType) &&
2430 getSize (fromType) != getSize (toType) &&
2431 SPEC_USIGN (fromType) == SPEC_USIGN (toType))
2434 iCode *dic = packRegsForOneuse (ic, IC_RIGHT (ic), ebp);
2437 if (IS_ARITHMETIC_OP (dic))
2439 IC_RESULT (dic) = IC_RESULT (ic);
2440 remiCodeFromeBBlock (ebp, ic);
2441 hTabDeleteItem (&iCodehTab, ic->key, ic, DELETE_ITEM, NULL);
2442 OP_DEFS (IC_RESULT (dic)) = bitVectSetBit (OP_DEFS (IC_RESULT (dic)), dic->key);
2446 OP_SYMBOL (IC_RIGHT (ic))->ruonly = 0;
2452 /* if the type from and type to are the same
2453 then if this is the only use then packit */
2454 if (compareType (operandType (IC_RIGHT (ic)),
2455 operandType (IC_LEFT (ic))) == 1)
2457 iCode *dic = packRegsForOneuse (ic, IC_RIGHT (ic), ebp);
2460 IC_RESULT (dic) = IC_RESULT (ic);
2461 remiCodeFromeBBlock (ebp, ic);
2462 hTabDeleteItem (&iCodehTab, ic->key, ic, DELETE_ITEM, NULL);
2463 OP_DEFS (IC_RESULT (dic)) = bitVectSetBit (OP_DEFS (IC_RESULT (dic)), dic->key);
2471 iTempNN := (some variable in farspace) V1
2476 if (ic->op == IPUSH)
2478 packForPush (ic, ebp);
2482 /* pack registers for accumulator use, when the
2483 result of an arithmetic or bit wise operation
2484 has only one use, that use is immediately following
2485 the defintion and the using iCode has only one
2486 operand or has two operands but one is literal &
2487 the result of that operation is not on stack then
2488 we can leave the result of this operation in acc:b
2490 if ((IS_ARITHMETIC_OP (ic)
2491 || IS_CONDITIONAL(ic)
2492 || IS_BITWISE_OP (ic)
2493 || ic->op == LEFT_OP || ic->op == RIGHT_OP
2494 || (ic->op == ADDRESS_OF && isOperandOnStack (IC_LEFT (ic)))
2496 IS_ITEMP (IC_RESULT (ic)) &&
2497 getSize (operandType (IC_RESULT (ic))) <= 2)
2499 packRegsForAccUse (ic);
2504 /*-----------------------------------------------------------------*/
2505 /* assignRegisters - assigns registers to each live range as need */
2506 /*-----------------------------------------------------------------*/
2508 ds390_assignRegisters (eBBlock ** ebbs, int count)
2513 setToNull ((void *) &_G.funcrUsed);
2514 ds390_ptrRegReq = _G.stackExtend = _G.dataExtend = 0;
2516 if (options.model != MODEL_FLAT24) options.stack10bit = 0;
2517 /* change assignments this will remove some
2518 live ranges reducing some register pressure */
2519 for (i = 0; i < count; i++)
2520 packRegisters (ebbs[i]);
2522 if (options.dump_pack)
2523 dumpEbbsToFileExt (DUMP_PACK, ebbs, count);
2525 /* first determine for each live range the number of
2526 registers & the type of registers required for each */
2529 /* and serially allocate registers */
2530 serialRegAssign (ebbs, count);
2532 /* if stack was extended then tell the user */
2535 /* werror(W_TOOMANY_SPILS,"stack", */
2536 /* _G.stackExtend,currFunc->name,""); */
2542 /* werror(W_TOOMANY_SPILS,"data space", */
2543 /* _G.dataExtend,currFunc->name,""); */
2547 /* after that create the register mask
2548 for each of the instruction */
2549 createRegMask (ebbs, count);
2551 /* redo that offsets for stacked automatic variables */
2552 redoStackOffsets ();
2554 if (options.dump_rassgn)
2555 dumpEbbsToFileExt (DUMP_RASSGN, ebbs, count);
2557 /* do the overlaysegment stuff SDCCmem.c */
2558 doOverlays (ebbs, count);
2560 /* now get back the chain */
2561 ic = iCodeLabelOptimize (iCodeFromeBBlock (ebbs, count));
2566 /* free up any _G.stackSpil locations allocated */
2567 applyToSet (_G.stackSpil, deallocStackSpil);
2569 setToNull ((void **) &_G.stackSpil);
2570 setToNull ((void **) &_G.spiltSet);
2571 /* mark all registers as free */