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)
384 for (sym = setFirstItem (itmpStack); sym;
385 sym = setNextItem (itmpStack))
387 if (sym->liveTo > fsym->liveFrom)
395 /*-----------------------------------------------------------------*/
396 /* isFree - will return 1 if the a free spil location is found */
397 /*-----------------------------------------------------------------*/
402 V_ARG (symbol **, sloc);
403 V_ARG (symbol *, fsym);
405 /* if already found */
409 /* if it is free && and the itmp assigned to
410 this does not have any overlapping live ranges
411 with the one currently being assigned and
412 the size can be accomodated */
414 noOverLap (sym->usl.itmpStack, fsym) &&
415 getSize (sym->type) >= getSize (fsym->type))
424 /*-----------------------------------------------------------------*/
425 /* spillLRWithPtrReg :- will spil those live ranges which use PTR */
426 /*-----------------------------------------------------------------*/
428 spillLRWithPtrReg (symbol * forSym)
434 if (!_G.regAssigned ||
435 bitVectIsZero (_G.regAssigned))
438 r0 = ds390_regWithIdx (R0_IDX);
439 r1 = ds390_regWithIdx (R1_IDX);
441 /* for all live ranges */
442 for (lrsym = hTabFirstItem (liveRanges, &k); lrsym;
443 lrsym = hTabNextItem (liveRanges, &k))
447 /* if no registers assigned to it or
449 /* if it does not overlap with this then
450 not need to spill it */
452 if (lrsym->isspilt || !lrsym->nRegs ||
453 (lrsym->liveTo < forSym->liveFrom))
456 /* go thru the registers : if it is either
457 r0 or r1 then spil it */
458 for (j = 0; j < lrsym->nRegs; j++)
459 if (lrsym->regs[j] == r0 ||
460 lrsym->regs[j] == r1)
469 /*-----------------------------------------------------------------*/
470 /* createStackSpil - create a location on the stack to spil */
471 /*-----------------------------------------------------------------*/
473 createStackSpil (symbol * sym)
476 int useXstack, model, noOverlay;
480 /* first go try and find a free one that is already
481 existing on the stack */
482 if (applyToSet (_G.stackSpil, isFree, &sloc, sym))
484 /* found a free one : just update & return */
485 sym->usl.spillLoc = sloc;
488 addSetHead (&sloc->usl.itmpStack, sym);
492 /* could not then have to create one , this is the hard part
493 we need to allocate this on the stack : this is really a
494 hack!! but cannot think of anything better at this time */
496 if (sprintf (slocBuffer, "sloc%d", _G.slocNum++) >= sizeof (slocBuffer))
498 fprintf (stderr, "***Internal error: slocBuffer overflowed: %s:%d\n",
503 sloc = newiTemp (slocBuffer);
505 /* set the type to the spilling symbol */
506 sloc->type = copyLinkChain (sym->type);
507 sloc->etype = getSpec (sloc->type);
508 SPEC_SCLS (sloc->etype) = options.model ? S_XDATA : S_DATA;
509 SPEC_EXTR (sloc->etype) = 0;
511 /* we don't allow it to be allocated`
512 onto the external stack since : so we
513 temporarily turn it off ; we also
514 turn off memory model to prevent
515 the spil from going to the external storage
516 and turn off overlaying
519 useXstack = options.useXstack;
520 model = options.model;
521 noOverlay = options.noOverlay;
522 options.noOverlay = 1;
524 /* options.model = options.useXstack = 0; */
528 options.useXstack = useXstack;
529 options.model = model;
530 options.noOverlay = noOverlay;
531 sloc->isref = 1; /* to prevent compiler warning */
533 /* if it is on the stack then update the stack */
534 if (IN_STACK (sloc->etype))
536 currFunc->stack += getSize (sloc->type);
537 _G.stackExtend += getSize (sloc->type);
540 _G.dataExtend += getSize (sloc->type);
542 /* add it to the _G.stackSpil set */
543 addSetHead (&_G.stackSpil, sloc);
544 sym->usl.spillLoc = sloc;
547 /* add it to the set of itempStack set
548 of the spill location */
549 addSetHead (&sloc->usl.itmpStack, sym);
553 /*-----------------------------------------------------------------*/
554 /* isSpiltOnStack - returns true if the spil location is on stack */
555 /*-----------------------------------------------------------------*/
557 isSpiltOnStack (symbol * sym)
567 /* if (sym->_G.stackSpil) */
570 if (!sym->usl.spillLoc)
573 etype = getSpec (sym->usl.spillLoc->type);
574 if (IN_STACK (etype))
580 /*-----------------------------------------------------------------*/
581 /* spillThis - spils a specific operand */
582 /*-----------------------------------------------------------------*/
584 spillThis (symbol * sym)
587 /* if this is rematerializable or has a spillLocation
588 we are okay, else we need to create a spillLocation
590 if (!(sym->remat || sym->usl.spillLoc))
591 createStackSpil (sym);
594 /* mark it has spilt & put it in the spilt set */
596 _G.spiltSet = bitVectSetBit (_G.spiltSet, sym->key);
598 bitVectUnSetBit (_G.regAssigned, sym->key);
600 for (i = 0; i < sym->nRegs; i++)
604 freeReg (sym->regs[i]);
608 /* if spilt on stack then free up r0 & r1
609 if they could have been assigned to some
611 if (!ds390_ptrRegReq && isSpiltOnStack (sym))
614 spillLRWithPtrReg (sym);
617 if (sym->usl.spillLoc && !sym->remat)
618 sym->usl.spillLoc->allocreq = 1;
622 /*-----------------------------------------------------------------*/
623 /* selectSpil - select a iTemp to spil : rather a simple procedure */
624 /*-----------------------------------------------------------------*/
626 selectSpil (iCode * ic, eBBlock * ebp, symbol * forSym)
628 bitVect *lrcs = NULL;
632 /* get the spillable live ranges */
633 lrcs = computeSpillable (ic);
635 /* get all live ranges that are rematerizable */
636 if ((selectS = liveRangesWith (lrcs, rematable, ebp, ic)))
639 /* return the least used of these */
640 return leastUsedLR (selectS);
643 /* get live ranges with spillLocations in direct space */
644 if ((selectS = liveRangesWith (lrcs, directSpilLoc, ebp, ic)))
646 sym = leastUsedLR (selectS);
647 strcpy (sym->rname, (sym->usl.spillLoc->rname[0] ?
648 sym->usl.spillLoc->rname :
649 sym->usl.spillLoc->name));
651 /* mark it as allocation required */
652 sym->usl.spillLoc->allocreq = 1;
656 /* if the symbol is local to the block then */
657 if (forSym->liveTo < ebp->lSeq)
660 /* check if there are any live ranges allocated
661 to registers that are not used in this block */
662 if (!_G.blockSpil && (selectS = liveRangesWith (lrcs, notUsedInBlock, ebp, ic)))
664 sym = leastUsedLR (selectS);
665 /* if this is not rematerializable */
674 /* check if there are any live ranges that not
675 used in the remainder of the block */
676 if (!_G.blockSpil && (selectS = liveRangesWith (lrcs, notUsedInRemaining, ebp, ic)))
678 sym = leastUsedLR (selectS);
691 /* find live ranges with spillocation && not used as pointers */
692 if ((selectS = liveRangesWith (lrcs, hasSpilLocnoUptr, ebp, ic)))
695 sym = leastUsedLR (selectS);
696 /* mark this as allocation required */
697 sym->usl.spillLoc->allocreq = 1;
701 /* find live ranges with spillocation */
702 if ((selectS = liveRangesWith (lrcs, hasSpilLoc, ebp, ic)))
705 sym = leastUsedLR (selectS);
706 sym->usl.spillLoc->allocreq = 1;
710 /* couldn't find then we need to create a spil
711 location on the stack , for which one? the least
713 if ((selectS = liveRangesWith (lrcs, noSpilLoc, ebp, ic)))
716 /* return a created spil location */
717 sym = createStackSpil (leastUsedLR (selectS));
718 sym->usl.spillLoc->allocreq = 1;
722 /* this is an extreme situation we will spill
723 this one : happens very rarely but it does happen */
729 /*-----------------------------------------------------------------*/
730 /* spilSomething - spil some variable & mark registers as free */
731 /*-----------------------------------------------------------------*/
733 spilSomething (iCode * ic, eBBlock * ebp, symbol * forSym)
738 /* get something we can spil */
739 ssym = selectSpil (ic, ebp, forSym);
741 /* mark it as spilt */
743 _G.spiltSet = bitVectSetBit (_G.spiltSet, ssym->key);
745 /* mark it as not register assigned &
746 take it away from the set */
747 bitVectUnSetBit (_G.regAssigned, ssym->key);
749 /* mark the registers as free */
750 for (i = 0; i < ssym->nRegs; i++)
752 freeReg (ssym->regs[i]);
754 /* if spilt on stack then free up r0 & r1
755 if they could have been assigned to as gprs */
756 if (!ds390_ptrRegReq && isSpiltOnStack (ssym))
759 spillLRWithPtrReg (ssym);
762 /* if this was a block level spil then insert push & pop
763 at the start & end of block respectively */
766 iCode *nic = newiCode (IPUSH, operandFromSymbol (ssym), NULL);
767 /* add push to the start of the block */
768 addiCodeToeBBlock (ebp, nic, (ebp->sch->op == LABEL ?
769 ebp->sch->next : ebp->sch));
770 nic = newiCode (IPOP, operandFromSymbol (ssym), NULL);
771 /* add pop to the end of the block */
772 addiCodeToeBBlock (ebp, nic, NULL);
775 /* if spilt because not used in the remainder of the
776 block then add a push before this instruction and
777 a pop at the end of the block */
778 if (ssym->remainSpil)
781 iCode *nic = newiCode (IPUSH, operandFromSymbol (ssym), NULL);
782 /* add push just before this instruction */
783 addiCodeToeBBlock (ebp, nic, ic);
785 nic = newiCode (IPOP, operandFromSymbol (ssym), NULL);
786 /* add pop to the end of the block */
787 addiCodeToeBBlock (ebp, nic, NULL);
796 /*-----------------------------------------------------------------*/
797 /* getRegPtr - will try for PTR if not a GPR type if not spil */
798 /*-----------------------------------------------------------------*/
800 getRegPtr (iCode * ic, eBBlock * ebp, symbol * sym)
805 /* try for a ptr type */
806 if ((reg = allocReg (REG_PTR)))
809 /* try for gpr type */
810 if ((reg = allocReg (REG_GPR)))
813 /* we have to spil */
814 if (!spilSomething (ic, ebp, sym))
817 /* this looks like an infinite loop but
818 in really selectSpil will abort */
822 /*-----------------------------------------------------------------*/
823 /* getRegGpr - will try for GPR if not spil */
824 /*-----------------------------------------------------------------*/
826 getRegGpr (iCode * ic, eBBlock * ebp, symbol * sym)
831 /* try for gpr type */
832 if ((reg = allocReg (REG_GPR)))
835 if (!ds390_ptrRegReq)
836 if ((reg = allocReg (REG_PTR)))
839 /* we have to spil */
840 if (!spilSomething (ic, ebp, sym))
843 /* this looks like an infinite loop but
844 in really selectSpil will abort */
848 /*-----------------------------------------------------------------*/
849 /* symHasReg - symbol has a given register */
850 /*-----------------------------------------------------------------*/
852 symHasReg (symbol * sym, regs * reg)
856 for (i = 0; i < sym->nRegs; i++)
857 if (sym->regs[i] == reg)
863 /*-----------------------------------------------------------------*/
864 /* deassignLRs - check the live to and if they have registers & are */
865 /* not spilt then free up the registers */
866 /*-----------------------------------------------------------------*/
868 deassignLRs (iCode * ic, eBBlock * ebp)
874 for (sym = hTabFirstItem (liveRanges, &k); sym;
875 sym = hTabNextItem (liveRanges, &k))
879 /* if it does not end here */
880 if (sym->liveTo > ic->seq)
883 /* if it was spilt on stack then we can
884 mark the stack spil location as free */
889 sym->usl.spillLoc->isFree = 1;
895 if (!bitVectBitValue (_G.regAssigned, sym->key))
898 /* special case check if this is an IFX &
899 the privious one was a pop and the
900 previous one was not spilt then keep track
902 if (ic->op == IFX && ic->prev &&
903 ic->prev->op == IPOP &&
904 !ic->prev->parmPush &&
905 !OP_SYMBOL (IC_LEFT (ic->prev))->isspilt)
906 psym = OP_SYMBOL (IC_LEFT (ic->prev));
912 bitVectUnSetBit (_G.regAssigned, sym->key);
914 /* if the result of this one needs registers
915 and does not have it then assign it right
917 if (IC_RESULT (ic) &&
918 !(SKIP_IC2 (ic) || /* not a special icode */
919 ic->op == JUMPTABLE ||
925 (result = OP_SYMBOL (IC_RESULT (ic))) && /* has a result */
926 result->liveTo > ic->seq && /* and will live beyond this */
927 result->liveTo <= ebp->lSeq && /* does not go beyond this block */
928 result->regType == sym->regType && /* same register types */
929 result->nRegs && /* which needs registers */
930 !result->isspilt && /* and does not already have them */
932 !bitVectBitValue (_G.regAssigned, result->key) &&
933 /* the number of free regs + number of regs in this LR
934 can accomodate the what result Needs */
935 ((nfreeRegsType (result->regType) +
936 sym->nRegs) >= result->nRegs)
940 for (i = 0; i < result->nRegs; i++)
942 result->regs[i] = sym->regs[i];
944 result->regs[i] = getRegGpr (ic, ebp, result);
946 _G.regAssigned = bitVectSetBit (_G.regAssigned, result->key);
950 /* free the remaining */
951 for (; i < sym->nRegs; i++)
955 if (!symHasReg (psym, sym->regs[i]))
956 freeReg (sym->regs[i]);
959 freeReg (sym->regs[i]);
966 /*-----------------------------------------------------------------*/
967 /* reassignLR - reassign this to registers */
968 /*-----------------------------------------------------------------*/
970 reassignLR (operand * op)
972 symbol *sym = OP_SYMBOL (op);
975 /* not spilt any more */
976 sym->isspilt = sym->blockSpil = sym->remainSpil = 0;
977 bitVectUnSetBit (_G.spiltSet, sym->key);
979 _G.regAssigned = bitVectSetBit (_G.regAssigned, sym->key);
983 for (i = 0; i < sym->nRegs; i++)
984 sym->regs[i]->isFree = 0;
987 /*-----------------------------------------------------------------*/
988 /* willCauseSpill - determines if allocating will cause a spill */
989 /*-----------------------------------------------------------------*/
991 willCauseSpill (int nr, int rt)
993 /* first check if there are any avlb registers
994 of te type required */
997 /* special case for pointer type
998 if pointer type not avlb then
999 check for type gpr */
1000 if (nFreeRegs (rt) >= nr)
1002 if (nFreeRegs (REG_GPR) >= nr)
1007 if (ds390_ptrRegReq)
1009 if (nFreeRegs (rt) >= nr)
1014 if (nFreeRegs (REG_PTR) +
1015 nFreeRegs (REG_GPR) >= nr)
1020 /* it will cause a spil */
1024 /*-----------------------------------------------------------------*/
1025 /* positionRegs - the allocator can allocate same registers to res- */
1026 /* ult and operand, if this happens make sure they are in the same */
1027 /* position as the operand otherwise chaos results */
1028 /*-----------------------------------------------------------------*/
1030 positionRegs (symbol * result, symbol * opsym, int lineno)
1032 int count = min (result->nRegs, opsym->nRegs);
1033 int i, j = 0, shared = 0;
1035 /* if the result has been spilt then cannot share */
1040 /* first make sure that they actually share */
1041 for (i = 0; i < count; i++)
1043 for (j = 0; j < count; j++)
1045 if (result->regs[i] == opsym->regs[j] && i != j)
1055 regs *tmp = result->regs[i];
1056 result->regs[i] = result->regs[j];
1057 result->regs[j] = tmp;
1062 /*-----------------------------------------------------------------*/
1063 /* serialRegAssign - serially allocate registers to the variables */
1064 /*-----------------------------------------------------------------*/
1066 serialRegAssign (eBBlock ** ebbs, int count)
1070 /* for all blocks */
1071 for (i = 0; i < count; i++)
1076 if (ebbs[i]->noPath &&
1077 (ebbs[i]->entryLabel != entryLabel &&
1078 ebbs[i]->entryLabel != returnLabel))
1081 /* of all instructions do */
1082 for (ic = ebbs[i]->sch; ic; ic = ic->next)
1085 /* if this is an ipop that means some live
1086 range will have to be assigned again */
1088 reassignLR (IC_LEFT (ic));
1090 /* if result is present && is a true symbol */
1091 if (IC_RESULT (ic) && ic->op != IFX &&
1092 IS_TRUE_SYMOP (IC_RESULT (ic)))
1093 OP_SYMBOL (IC_RESULT (ic))->allocreq = 1;
1095 /* take away registers from live
1096 ranges that end at this instruction */
1097 deassignLRs (ic, ebbs[i]);
1099 /* some don't need registers */
1100 if (SKIP_IC2 (ic) ||
1101 ic->op == JUMPTABLE ||
1105 (IC_RESULT (ic) && POINTER_SET (ic)))
1108 /* now we need to allocate registers
1109 only for the result */
1112 symbol *sym = OP_SYMBOL (IC_RESULT (ic));
1118 /* if it does not need or is spilt
1119 or is already assigned to registers
1120 or will not live beyond this instructions */
1123 bitVectBitValue (_G.regAssigned, sym->key) ||
1124 sym->liveTo <= ic->seq)
1127 /* if some liverange has been spilt at the block level
1128 and this one live beyond this block then spil this
1130 if (_G.blockSpil && sym->liveTo > ebbs[i]->lSeq)
1135 /* if trying to allocate this will cause
1136 a spill and there is nothing to spill
1137 or this one is rematerializable then
1139 willCS = willCauseSpill (sym->nRegs, sym->regType);
1140 spillable = computeSpillable (ic);
1142 (willCS && bitVectIsZero (spillable)))
1150 /* if it has a spillocation & is used less than
1151 all other live ranges then spill this */
1153 if (sym->usl.spillLoc) {
1154 symbol *leastUsed = leastUsedLR (liveRangesWith (spillable,
1155 allLRs, ebbs[i], ic));
1156 if (leastUsed && leastUsed->used > sym->used) {
1161 /* if none of the liveRanges have a spillLocation then better
1162 to spill this one than anything else already assigned to registers */
1163 if (liveRangesWith(spillable,noSpilLoc,ebbs[i],ic)) {
1170 /* if we need ptr regs for the right side
1172 if (POINTER_GET (ic) && IS_SYMOP (IC_LEFT (ic))
1173 && getSize (OP_SYMBOL (IC_LEFT (ic))->type)
1174 <= (unsigned) PTRSIZE)
1179 /* else we assign registers to it */
1180 _G.regAssigned = bitVectSetBit (_G.regAssigned, sym->key);
1182 for (j = 0; j < sym->nRegs; j++)
1184 if (sym->regType == REG_PTR)
1185 sym->regs[j] = getRegPtr (ic, ebbs[i], sym);
1187 sym->regs[j] = getRegGpr (ic, ebbs[i], sym);
1189 /* if the allocation falied which means
1190 this was spilt then break */
1194 /* if it shares registers with operands make sure
1195 that they are in the same position */
1196 if (IC_LEFT (ic) && IS_SYMOP (IC_LEFT (ic)) &&
1197 OP_SYMBOL (IC_LEFT (ic))->nRegs && ic->op != '=')
1198 positionRegs (OP_SYMBOL (IC_RESULT (ic)),
1199 OP_SYMBOL (IC_LEFT (ic)), ic->lineno);
1200 /* do the same for the right operand */
1201 if (IC_RIGHT (ic) && IS_SYMOP (IC_RIGHT (ic)) &&
1202 OP_SYMBOL (IC_RIGHT (ic))->nRegs)
1203 positionRegs (OP_SYMBOL (IC_RESULT (ic)),
1204 OP_SYMBOL (IC_RIGHT (ic)), ic->lineno);
1217 /*-----------------------------------------------------------------*/
1218 /* rUmaskForOp :- returns register mask for an operand */
1219 /*-----------------------------------------------------------------*/
1221 rUmaskForOp (operand * op)
1227 /* only temporaries are assigned registers */
1231 sym = OP_SYMBOL (op);
1233 /* if spilt or no registers assigned to it
1235 if (sym->isspilt || !sym->nRegs)
1238 rumask = newBitVect (ds390_nRegs);
1240 for (j = 0; j < sym->nRegs; j++)
1242 rumask = bitVectSetBit (rumask,
1243 sym->regs[j]->rIdx);
1249 /*-----------------------------------------------------------------*/
1250 /* regsUsedIniCode :- returns bit vector of registers used in iCode */
1251 /*-----------------------------------------------------------------*/
1253 regsUsedIniCode (iCode * ic)
1255 bitVect *rmask = newBitVect (ds390_nRegs);
1257 /* do the special cases first */
1260 rmask = bitVectUnion (rmask,
1261 rUmaskForOp (IC_COND (ic)));
1265 /* for the jumptable */
1266 if (ic->op == JUMPTABLE)
1268 rmask = bitVectUnion (rmask,
1269 rUmaskForOp (IC_JTCOND (ic)));
1274 /* of all other cases */
1276 rmask = bitVectUnion (rmask,
1277 rUmaskForOp (IC_LEFT (ic)));
1281 rmask = bitVectUnion (rmask,
1282 rUmaskForOp (IC_RIGHT (ic)));
1285 rmask = bitVectUnion (rmask,
1286 rUmaskForOp (IC_RESULT (ic)));
1292 /*-----------------------------------------------------------------*/
1293 /* createRegMask - for each instruction will determine the regsUsed */
1294 /*-----------------------------------------------------------------*/
1296 createRegMask (eBBlock ** ebbs, int count)
1300 /* for all blocks */
1301 for (i = 0; i < count; i++)
1305 if (ebbs[i]->noPath &&
1306 (ebbs[i]->entryLabel != entryLabel &&
1307 ebbs[i]->entryLabel != returnLabel))
1310 /* for all instructions */
1311 for (ic = ebbs[i]->sch; ic; ic = ic->next)
1316 if (SKIP_IC2 (ic) || !ic->rlive)
1319 /* first mark the registers used in this
1321 ic->rUsed = regsUsedIniCode (ic);
1322 _G.funcrUsed = bitVectUnion (_G.funcrUsed, ic->rUsed);
1324 /* now create the register mask for those
1325 registers that are in use : this is a
1326 super set of ic->rUsed */
1327 ic->rMask = newBitVect (ds390_nRegs + 1);
1329 /* for all live Ranges alive at this point */
1330 for (j = 1; j < ic->rlive->size; j++)
1335 /* if not alive then continue */
1336 if (!bitVectBitValue (ic->rlive, j))
1339 /* find the live range we are interested in */
1340 if (!(sym = hTabItemWithKey (liveRanges, j)))
1342 werror (E_INTERNAL_ERROR, __FILE__, __LINE__,
1343 "createRegMask cannot find live range");
1347 /* if no register assigned to it */
1348 if (!sym->nRegs || sym->isspilt)
1351 /* for all the registers allocated to it */
1352 for (k = 0; k < sym->nRegs; k++)
1355 bitVectSetBit (ic->rMask, sym->regs[k]->rIdx);
1361 /*-----------------------------------------------------------------*/
1362 /* rematStr - returns the rematerialized string for a remat var */
1363 /*-----------------------------------------------------------------*/
1365 rematStr (symbol * sym)
1368 iCode *ic = sym->rematiCode;
1373 /* if plus or minus print the right hand side */
1374 if (ic->op == '+' || ic->op == '-')
1376 sprintf (s, "0x%04x %c ", (int) operandLitValue (IC_RIGHT (ic)),
1379 ic = OP_SYMBOL (IC_LEFT (ic))->rematiCode;
1383 /* we reached the end */
1384 sprintf (s, "%s", OP_SYMBOL (IC_LEFT (ic))->rname);
1391 /*-----------------------------------------------------------------*/
1392 /* regTypeNum - computes the type & number of registers required */
1393 /*-----------------------------------------------------------------*/
1401 /* for each live range do */
1402 for (sym = hTabFirstItem (liveRanges, &k); sym;
1403 sym = hTabNextItem (liveRanges, &k))
1406 /* if used zero times then no registers needed */
1407 if ((sym->liveTo - sym->liveFrom) == 0)
1411 /* if the live range is a temporary */
1415 /* if the type is marked as a conditional */
1416 if (sym->regType == REG_CND)
1419 /* if used in return only then we don't
1421 if (sym->ruonly || sym->accuse)
1423 if (IS_AGGREGATE (sym->type) || sym->isptr)
1424 sym->type = aggrToPtr (sym->type, FALSE);
1428 /* if the symbol has only one definition &
1429 that definition is a get_pointer and the
1430 pointer we are getting is rematerializable and
1433 if (bitVectnBitsOn (sym->defs) == 1 &&
1434 (ic = hTabItemWithKey (iCodehTab,
1435 bitVectFirstBit (sym->defs))) &&
1437 !IS_BITVAR (sym->etype))
1441 /* if remat in data space */
1442 if (OP_SYMBOL (IC_LEFT (ic))->remat &&
1444 DCL_TYPE (aggrToPtr (sym->type, FALSE)) == POINTER)
1447 /* create a psuedo symbol & force a spil */
1448 symbol *psym = newSymbol (rematStr (OP_SYMBOL (IC_LEFT (ic))), 1);
1449 psym->type = sym->type;
1450 psym->etype = sym->etype;
1451 strcpy (psym->rname, psym->name);
1453 sym->usl.spillLoc = psym;
1457 /* if in data space or idata space then try to
1458 allocate pointer register */
1462 /* if not then we require registers */
1463 sym->nRegs = ((IS_AGGREGATE (sym->type) || sym->isptr) ?
1464 getSize (sym->type = aggrToPtr (sym->type, FALSE)) :
1465 getSize (sym->type));
1469 fprintf (stderr, "allocated more than 4 or 0 registers for type ");
1470 printTypeChain (sym->type, stderr);
1471 fprintf (stderr, "\n");
1474 /* determine the type of register required */
1475 if (sym->nRegs == 1 &&
1476 IS_PTR (sym->type) &&
1478 sym->regType = REG_PTR;
1480 sym->regType = REG_GPR;
1484 /* for the first run we don't provide */
1485 /* registers for true symbols we will */
1486 /* see how things go */
1492 /*-----------------------------------------------------------------*/
1493 /* freeAllRegs - mark all registers as free */
1494 /*-----------------------------------------------------------------*/
1500 for (i = 0; i < ds390_nRegs; i++)
1501 regs390[i].isFree = 1;
1504 /*-----------------------------------------------------------------*/
1505 /* deallocStackSpil - this will set the stack pointer back */
1506 /*-----------------------------------------------------------------*/
1508 DEFSETFUNC (deallocStackSpil)
1516 /*-----------------------------------------------------------------*/
1517 /* farSpacePackable - returns the packable icode for far variables */
1518 /*-----------------------------------------------------------------*/
1520 farSpacePackable (iCode * ic)
1524 /* go thru till we find a definition for the
1525 symbol on the right */
1526 for (dic = ic->prev; dic; dic = dic->prev)
1529 /* if the definition is a call then no */
1530 if ((dic->op == CALL || dic->op == PCALL) &&
1531 IC_RESULT (dic)->key == IC_RIGHT (ic)->key)
1536 /* if shift by unknown amount then not */
1537 if ((dic->op == LEFT_OP || dic->op == RIGHT_OP) &&
1538 IC_RESULT (dic)->key == IC_RIGHT (ic)->key)
1541 /* if pointer get and size > 1 */
1542 if (POINTER_GET (dic) &&
1543 getSize (aggrToPtr (operandType (IC_LEFT (dic)), FALSE)) > 1)
1546 if (POINTER_SET (dic) &&
1547 getSize (aggrToPtr (operandType (IC_RESULT (dic)), FALSE)) > 1)
1550 /* if any three is a true symbol in far space */
1551 if (IC_RESULT (dic) &&
1552 IS_TRUE_SYMOP (IC_RESULT (dic)) &&
1553 isOperandInFarSpace (IC_RESULT (dic)))
1556 if (IC_RIGHT (dic) &&
1557 IS_TRUE_SYMOP (IC_RIGHT (dic)) &&
1558 isOperandInFarSpace (IC_RIGHT (dic)) &&
1559 !isOperandEqual (IC_RIGHT (dic), IC_RESULT (ic)))
1562 if (IC_LEFT (dic) &&
1563 IS_TRUE_SYMOP (IC_LEFT (dic)) &&
1564 isOperandInFarSpace (IC_LEFT (dic)) &&
1565 !isOperandEqual (IC_LEFT (dic), IC_RESULT (ic)))
1568 if (isOperandEqual (IC_RIGHT (ic), IC_RESULT (dic)))
1570 if ((dic->op == LEFT_OP ||
1571 dic->op == RIGHT_OP ||
1573 IS_OP_LITERAL (IC_RIGHT (dic)))
1583 /*-----------------------------------------------------------------*/
1584 /* packRegsForAssign - register reduction for assignment */
1585 /*-----------------------------------------------------------------*/
1587 packRegsForAssign (iCode * ic, eBBlock * ebp)
1591 if (!IS_ITEMP (IC_RIGHT (ic)) ||
1592 OP_SYMBOL (IC_RIGHT (ic))->isind ||
1593 OP_LIVETO (IC_RIGHT (ic)) > ic->seq)
1598 /* if the true symbol is defined in far space or on stack
1599 then we should not since this will increase register pressure */
1601 if (isOperandInFarSpace (IC_RESULT (ic)))
1603 if ((dic = farSpacePackable (ic)))
1609 if (isOperandInFarSpace(IC_RESULT(ic)) && !farSpacePackable(ic)) {
1614 /* find the definition of iTempNN scanning backwards if we find a
1615 a use of the true symbol in before we find the definition then
1617 for (dic = ic->prev; dic; dic = dic->prev)
1619 #if 0 // jwk 20010410, the JanVanBelle case
1620 /* if there is a function call and this is
1621 a parameter & not my parameter then don't pack it */
1622 if ((dic->op == CALL || dic->op == PCALL) &&
1623 (OP_SYMBOL (IC_RESULT (ic))->_isparm &&
1624 !OP_SYMBOL (IC_RESULT (ic))->ismyparm))
1630 /* if there is a function call then don't pack it */
1631 if ((dic->op == CALL || dic->op == PCALL))
1641 if (IS_TRUE_SYMOP (IC_RESULT (dic)) &&
1642 IS_OP_VOLATILE (IC_RESULT (dic)))
1648 if (IS_SYMOP (IC_RESULT (dic)) &&
1649 IC_RESULT (dic)->key == IC_RIGHT (ic)->key)
1651 if (POINTER_SET (dic))
1657 if (IS_SYMOP (IC_RIGHT (dic)) &&
1658 (IC_RIGHT (dic)->key == IC_RESULT (ic)->key ||
1659 IC_RIGHT (dic)->key == IC_RIGHT (ic)->key))
1665 if (IS_SYMOP (IC_LEFT (dic)) &&
1666 (IC_LEFT (dic)->key == IC_RESULT (ic)->key ||
1667 IC_LEFT (dic)->key == IC_RIGHT (ic)->key))
1673 if (POINTER_SET (dic) &&
1674 IC_RESULT (dic)->key == IC_RESULT (ic)->key)
1682 return 0; /* did not find */
1684 /* if the result is on stack or iaccess then it must be
1685 the same atleast one of the operands */
1686 if (OP_SYMBOL (IC_RESULT (ic))->onStack ||
1687 OP_SYMBOL (IC_RESULT (ic))->iaccess)
1690 /* the operation has only one symbol
1691 operator then we can pack */
1692 if ((IC_LEFT (dic) && !IS_SYMOP (IC_LEFT (dic))) ||
1693 (IC_RIGHT (dic) && !IS_SYMOP (IC_RIGHT (dic))))
1696 if (!((IC_LEFT (dic) &&
1697 IC_RESULT (ic)->key == IC_LEFT (dic)->key) ||
1699 IC_RESULT (ic)->key == IC_RIGHT (dic)->key)))
1703 /* found the definition */
1704 /* replace the result with the result of */
1705 /* this assignment and remove this assignment */
1706 IC_RESULT (dic) = IC_RESULT (ic);
1708 if (IS_ITEMP (IC_RESULT (dic)) && OP_SYMBOL (IC_RESULT (dic))->liveFrom > dic->seq)
1710 OP_SYMBOL (IC_RESULT (dic))->liveFrom = dic->seq;
1712 /* delete from liverange table also
1713 delete from all the points inbetween and the new
1715 for (sic = dic; sic != ic; sic = sic->next)
1717 bitVectUnSetBit (sic->rlive, IC_RESULT (ic)->key);
1718 if (IS_ITEMP (IC_RESULT (dic)))
1719 bitVectSetBit (sic->rlive, IC_RESULT (dic)->key);
1722 remiCodeFromeBBlock (ebp, ic);
1723 hTabDeleteItem (&iCodehTab, ic->key, ic, DELETE_ITEM, NULL);
1724 OP_DEFS (IC_RESULT (dic)) = bitVectSetBit (OP_DEFS (IC_RESULT (dic)), dic->key);
1729 /*-----------------------------------------------------------------*/
1730 /* findAssignToSym : scanning backwards looks for first assig found */
1731 /*-----------------------------------------------------------------*/
1733 findAssignToSym (operand * op, iCode * ic)
1737 for (dic = ic->prev; dic; dic = dic->prev)
1740 /* if definition by assignment */
1741 if (dic->op == '=' &&
1742 !POINTER_SET (dic) &&
1743 IC_RESULT (dic)->key == op->key
1744 /* && IS_TRUE_SYMOP(IC_RIGHT(dic)) */
1748 /* we are interested only if defined in far space */
1749 /* or in stack space in case of + & - */
1751 /* if assigned to a non-symbol then return
1753 if (!IS_SYMOP (IC_RIGHT (dic)))
1756 /* if the symbol is in far space then
1758 if (isOperandInFarSpace (IC_RIGHT (dic)))
1761 /* for + & - operations make sure that
1762 if it is on the stack it is the same
1763 as one of the three operands */
1764 if ((ic->op == '+' || ic->op == '-') &&
1765 OP_SYMBOL (IC_RIGHT (dic))->onStack)
1768 if (IC_RESULT (ic)->key != IC_RIGHT (dic)->key &&
1769 IC_LEFT (ic)->key != IC_RIGHT (dic)->key &&
1770 IC_RIGHT (ic)->key != IC_RIGHT (dic)->key)
1778 /* if we find an usage then we cannot delete it */
1779 if (IC_LEFT (dic) && IC_LEFT (dic)->key == op->key)
1782 if (IC_RIGHT (dic) && IC_RIGHT (dic)->key == op->key)
1785 if (POINTER_SET (dic) && IC_RESULT (dic)->key == op->key)
1789 /* now make sure that the right side of dic
1790 is not defined between ic & dic */
1793 iCode *sic = dic->next;
1795 for (; sic != ic; sic = sic->next)
1796 if (IC_RESULT (sic) &&
1797 IC_RESULT (sic)->key == IC_RIGHT (dic)->key)
1806 /*-----------------------------------------------------------------*/
1807 /* packRegsForSupport :- reduce some registers for support calls */
1808 /*-----------------------------------------------------------------*/
1810 packRegsForSupport (iCode * ic, eBBlock * ebp)
1813 /* for the left & right operand :- look to see if the
1814 left was assigned a true symbol in far space in that
1815 case replace them */
1816 if (IS_ITEMP (IC_LEFT (ic)) &&
1817 OP_SYMBOL (IC_LEFT (ic))->liveTo <= ic->seq)
1819 iCode *dic = findAssignToSym (IC_LEFT (ic), ic);
1825 /* found it we need to remove it from the
1827 for (sic = dic; sic != ic; sic = sic->next)
1828 bitVectUnSetBit (sic->rlive, IC_LEFT (ic)->key);
1830 IC_LEFT (ic)->operand.symOperand =
1831 IC_RIGHT (dic)->operand.symOperand;
1832 IC_LEFT (ic)->key = IC_RIGHT (dic)->operand.symOperand->key;
1833 remiCodeFromeBBlock (ebp, dic);
1834 hTabDeleteItem (&iCodehTab, dic->key, dic, DELETE_ITEM, NULL);
1838 /* do the same for the right operand */
1841 IS_ITEMP (IC_RIGHT (ic)) &&
1842 OP_SYMBOL (IC_RIGHT (ic))->liveTo <= ic->seq)
1844 iCode *dic = findAssignToSym (IC_RIGHT (ic), ic);
1850 /* if this is a subtraction & the result
1851 is a true symbol in far space then don't pack */
1852 if (ic->op == '-' && IS_TRUE_SYMOP (IC_RESULT (dic)))
1854 sym_link *etype = getSpec (operandType (IC_RESULT (dic)));
1855 if (IN_FARSPACE (SPEC_OCLS (etype)))
1858 /* found it we need to remove it from the
1860 for (sic = dic; sic != ic; sic = sic->next)
1861 bitVectUnSetBit (sic->rlive, IC_RIGHT (ic)->key);
1863 IC_RIGHT (ic)->operand.symOperand =
1864 IC_RIGHT (dic)->operand.symOperand;
1865 IC_RIGHT (ic)->key = IC_RIGHT (dic)->operand.symOperand->key;
1867 remiCodeFromeBBlock (ebp, dic);
1868 hTabDeleteItem (&iCodehTab, dic->key, dic, DELETE_ITEM, NULL);
1875 #define IS_OP_RUONLY(x) (x && IS_SYMOP(x) && OP_SYMBOL(x)->ruonly)
1878 /*-----------------------------------------------------------------*/
1879 /* packRegsForOneuse : - will reduce some registers for single Use */
1880 /*-----------------------------------------------------------------*/
1882 packRegsForOneuse (iCode * ic, operand * op, eBBlock * ebp)
1886 /* I can't figure out how to make this safe yet. */
1887 if ((int)ic+(int)op+(int)ebp) {
1898 /* if returning a literal then do nothing */
1902 /* only upto 2 bytes since we cannot predict
1903 the usage of b, & acc */
1904 if (getSize (operandType (op)) > (fReturnSizeDS390 - 2) &&
1907 !POINTER_SET (ic) &&
1911 /* this routine will mark the a symbol as used in one
1912 instruction use only && if the defintion is local
1913 (ie. within the basic block) && has only one definition &&
1914 that definiion is either a return value from a
1915 function or does not contain any variables in
1917 uses = bitVectCopy (OP_USES (op));
1918 bitVectUnSetBit (uses, ic->key); /* take away this iCode */
1919 if (!bitVectIsZero (uses)) /* has other uses */
1922 /* if it has only one defintion */
1923 if (bitVectnBitsOn (OP_DEFS (op)) > 1)
1924 return NULL; /* has more than one definition */
1926 /* get the that definition */
1928 hTabItemWithKey (iCodehTab,
1929 bitVectFirstBit (OP_DEFS (op)))))
1932 /* found the definition now check if it is local */
1933 if (dic->seq < ebp->fSeq ||
1934 dic->seq > ebp->lSeq)
1935 return NULL; /* non-local */
1937 /* now check if it is the return from
1939 if (dic->op == CALL || dic->op == PCALL)
1941 if (ic->op != SEND && ic->op != RETURN)
1943 OP_SYMBOL (op)->ruonly = 1;
1950 /* otherwise check that the definition does
1951 not contain any symbols in far space */
1952 if (isOperandInFarSpace (IC_LEFT (dic)) ||
1953 isOperandInFarSpace (IC_RIGHT (dic)) ||
1954 IS_OP_RUONLY (IC_LEFT (ic)) ||
1955 IS_OP_RUONLY (IC_RIGHT (ic)))
1960 /* if pointer set then make sure the pointer
1962 if (POINTER_SET (dic) &&
1963 !IS_DATA_PTR (aggrToPtr (operandType (IC_RESULT (dic)), FALSE)))
1966 if (POINTER_GET (dic) &&
1967 !IS_DATA_PTR (aggrToPtr (operandType (IC_LEFT (dic)), FALSE)))
1972 /* also make sure the intervenening instructions
1973 don't have any thing in far space */
1974 for (dic = dic->next; dic && dic != ic; dic = dic->next)
1977 /* if there is an intervening function call then no */
1978 if (dic->op == CALL || dic->op == PCALL)
1980 /* if pointer set then make sure the pointer
1982 if (POINTER_SET (dic) &&
1983 !IS_DATA_PTR (aggrToPtr (operandType (IC_RESULT (dic)), FALSE)))
1986 if (POINTER_GET (dic) &&
1987 !IS_DATA_PTR (aggrToPtr (operandType (IC_LEFT (dic)), FALSE)))
1990 /* if address of & the result is remat the okay */
1991 if (dic->op == ADDRESS_OF &&
1992 OP_SYMBOL (IC_RESULT (dic))->remat)
1995 /* if operand has size of three or more & this
1996 operation is a '*','/' or '%' then 'b' may
1998 if ((dic->op == '%' || dic->op == '/' || dic->op == '*') &&
1999 getSize (operandType (op)) >= 3)
2002 /* if left or right or result is in far space */
2003 if (isOperandInFarSpace (IC_LEFT (dic)) ||
2004 isOperandInFarSpace (IC_RIGHT (dic)) ||
2005 isOperandInFarSpace (IC_RESULT (dic)) ||
2006 IS_OP_RUONLY (IC_LEFT (dic)) ||
2007 IS_OP_RUONLY (IC_RIGHT (dic)) ||
2008 IS_OP_RUONLY (IC_RESULT (dic)))
2014 OP_SYMBOL (op)->ruonly = 1;
2019 /*-----------------------------------------------------------------*/
2020 /* isBitwiseOptimizable - requirements of JEAN LOUIS VERN */
2021 /*-----------------------------------------------------------------*/
2023 isBitwiseOptimizable (iCode * ic)
2025 sym_link *ltype = getSpec (operandType (IC_LEFT (ic)));
2026 sym_link *rtype = getSpec (operandType (IC_RIGHT (ic)));
2028 /* bitwise operations are considered optimizable
2029 under the following conditions (Jean-Louis VERN)
2041 if ( IS_LITERAL (rtype) ||
2042 (IS_BITVAR (ltype) && IN_BITSPACE (SPEC_OCLS (ltype))))
2048 /*-----------------------------------------------------------------*/
2049 /* packRegsForAccUse - pack registers for acc use */
2050 /*-----------------------------------------------------------------*/
2052 packRegsForAccUse (iCode * ic)
2056 /* if + or - then it has to be one byte result */
2057 if ((ic->op == '+' || ic->op == '-')
2058 && getSize (operandType (IC_RESULT (ic))) > 1)
2061 /* if shift operation make sure right side is not a literal */
2062 if (ic->op == RIGHT_OP &&
2063 (isOperandLiteral (IC_RIGHT (ic)) ||
2064 getSize (operandType (IC_RESULT (ic))) > 1))
2067 if (ic->op == LEFT_OP &&
2068 (isOperandLiteral (IC_RIGHT (ic)) ||
2069 getSize (operandType (IC_RESULT (ic))) > 1))
2072 if (IS_BITWISE_OP (ic) &&
2073 getSize (operandType (IC_RESULT (ic))) > 1)
2077 /* has only one definition */
2078 if (bitVectnBitsOn (OP_DEFS (IC_RESULT (ic))) > 1)
2081 /* has only one use */
2082 if (bitVectnBitsOn (OP_USES (IC_RESULT (ic))) > 1)
2085 /* and the usage immediately follows this iCode */
2086 if (!(uic = hTabItemWithKey (iCodehTab,
2087 bitVectFirstBit (OP_USES (IC_RESULT (ic))))))
2090 if (ic->next != uic)
2093 /* if it is a conditional branch then we definitely can */
2097 if (uic->op == JUMPTABLE)
2100 /* if the usage is not is an assignment
2101 or an arithmetic / bitwise / shift operation then not */
2102 if (POINTER_SET (uic) &&
2103 getSize (aggrToPtr (operandType (IC_RESULT (uic)), FALSE)) > 1)
2106 if (uic->op != '=' &&
2107 !IS_ARITHMETIC_OP (uic) &&
2108 !IS_BITWISE_OP (uic) &&
2109 uic->op != LEFT_OP &&
2110 uic->op != RIGHT_OP)
2113 /* if used in ^ operation then make sure right is not a
2115 if (uic->op == '^' && isOperandLiteral (IC_RIGHT (uic)))
2118 /* if shift operation make sure right side is not a literal */
2119 if (uic->op == RIGHT_OP &&
2120 (isOperandLiteral (IC_RIGHT (uic)) ||
2121 getSize (operandType (IC_RESULT (uic))) > 1))
2124 if (uic->op == LEFT_OP &&
2125 (isOperandLiteral (IC_RIGHT (uic)) ||
2126 getSize (operandType (IC_RESULT (uic))) > 1))
2129 /* make sure that the result of this icode is not on the
2130 stack, since acc is used to compute stack offset */
2131 if (IS_TRUE_SYMOP (IC_RESULT (uic)) &&
2132 OP_SYMBOL (IC_RESULT (uic))->onStack)
2135 /* if either one of them in far space then we cannot */
2136 if ((IS_TRUE_SYMOP (IC_LEFT (uic)) &&
2137 isOperandInFarSpace (IC_LEFT (uic))) ||
2138 (IS_TRUE_SYMOP (IC_RIGHT (uic)) &&
2139 isOperandInFarSpace (IC_RIGHT (uic))))
2142 /* if the usage has only one operand then we can */
2143 if (IC_LEFT (uic) == NULL ||
2144 IC_RIGHT (uic) == NULL)
2147 /* make sure this is on the left side if not
2148 a '+' since '+' is commutative */
2149 if (ic->op != '+' &&
2150 IC_LEFT (uic)->key != IC_RESULT (ic)->key)
2153 /* if one of them is a literal then we can */
2154 if ((IC_LEFT (uic) && IS_OP_LITERAL (IC_LEFT (uic))) ||
2155 (IC_RIGHT (uic) && IS_OP_LITERAL (IC_RIGHT (uic))))
2157 OP_SYMBOL (IC_RESULT (ic))->accuse = 1;
2161 /* if the other one is not on stack then we can */
2162 if (IC_LEFT (uic)->key == IC_RESULT (ic)->key &&
2163 (IS_ITEMP (IC_RIGHT (uic)) ||
2164 (IS_TRUE_SYMOP (IC_RIGHT (uic)) &&
2165 !OP_SYMBOL (IC_RIGHT (uic))->onStack)))
2168 if (IC_RIGHT (uic)->key == IC_RESULT (ic)->key &&
2169 (IS_ITEMP (IC_LEFT (uic)) ||
2170 (IS_TRUE_SYMOP (IC_LEFT (uic)) &&
2171 !OP_SYMBOL (IC_LEFT (uic))->onStack)))
2177 OP_SYMBOL (IC_RESULT (ic))->accuse = 1;
2182 /*-----------------------------------------------------------------*/
2183 /* packForPush - hueristics to reduce iCode for pushing */
2184 /*-----------------------------------------------------------------*/
2186 packForPush (iCode * ic, eBBlock * ebp)
2191 if (ic->op != IPUSH || !IS_ITEMP (IC_LEFT (ic)))
2194 /* must have only definition & one usage */
2195 if (bitVectnBitsOn (OP_DEFS (IC_LEFT (ic))) != 1 ||
2196 bitVectnBitsOn (OP_USES (IC_LEFT (ic))) != 1)
2199 /* find the definition */
2200 if (!(dic = hTabItemWithKey (iCodehTab,
2201 bitVectFirstBit (OP_DEFS (IC_LEFT (ic))))))
2204 if (dic->op != '=' || POINTER_SET (dic))
2207 /* make sure the right side does not have any definitions
2209 dbv = OP_DEFS(IC_RIGHT(dic));
2210 for (lic = ic; lic != dic ; lic = lic->prev) {
2211 if (bitVectBitValue(dbv,lic->key)) return ;
2214 /* we now we know that it has one & only one def & use
2215 and the that the definition is an assignment */
2216 IC_LEFT (ic) = IC_RIGHT (dic);
2218 remiCodeFromeBBlock (ebp, dic);
2219 hTabDeleteItem (&iCodehTab, dic->key, dic, DELETE_ITEM, NULL);
2222 /*-----------------------------------------------------------------*/
2223 /* packRegisters - does some transformations to reduce register */
2225 /*-----------------------------------------------------------------*/
2227 packRegisters (eBBlock * ebp)
2237 /* look for assignments of the form */
2238 /* iTempNN = TRueSym (someoperation) SomeOperand */
2240 /* TrueSym := iTempNN:1 */
2241 for (ic = ebp->sch; ic; ic = ic->next)
2245 /* find assignment of the form TrueSym := iTempNN:1 */
2246 if (ic->op == '=' && !POINTER_SET (ic))
2247 change += packRegsForAssign (ic, ebp);
2254 for (ic = ebp->sch; ic; ic = ic->next)
2257 /* if this is an itemp & result of a address of a true sym
2258 then mark this as rematerialisable */
2259 if (ic->op == ADDRESS_OF &&
2260 IS_ITEMP (IC_RESULT (ic)) &&
2261 IS_TRUE_SYMOP (IC_LEFT (ic)) &&
2262 bitVectnBitsOn (OP_DEFS (IC_RESULT (ic))) == 1 &&
2263 !OP_SYMBOL (IC_LEFT (ic))->onStack)
2266 OP_SYMBOL (IC_RESULT (ic))->remat = 1;
2267 OP_SYMBOL (IC_RESULT (ic))->rematiCode = ic;
2268 OP_SYMBOL (IC_RESULT (ic))->usl.spillLoc = NULL;
2272 /* if straight assignment then carry remat flag if
2273 this is the only definition */
2274 if (ic->op == '=' &&
2275 !POINTER_SET (ic) &&
2276 IS_SYMOP (IC_RIGHT (ic)) &&
2277 OP_SYMBOL (IC_RIGHT (ic))->remat &&
2278 bitVectnBitsOn (OP_SYMBOL (IC_RESULT (ic))->defs) <= 1)
2281 OP_SYMBOL (IC_RESULT (ic))->remat =
2282 OP_SYMBOL (IC_RIGHT (ic))->remat;
2283 OP_SYMBOL (IC_RESULT (ic))->rematiCode =
2284 OP_SYMBOL (IC_RIGHT (ic))->rematiCode;
2287 /* if this is a +/- operation with a rematerizable
2288 then mark this as rematerializable as well */
2289 if ((ic->op == '+' || ic->op == '-') &&
2290 (IS_SYMOP (IC_LEFT (ic)) &&
2291 IS_ITEMP (IC_RESULT (ic)) &&
2292 OP_SYMBOL (IC_LEFT (ic))->remat &&
2293 bitVectnBitsOn (OP_DEFS (IC_RESULT (ic))) == 1 &&
2294 IS_OP_LITERAL (IC_RIGHT (ic))))
2297 //int i = operandLitValue(IC_RIGHT(ic));
2298 OP_SYMBOL (IC_RESULT (ic))->remat = 1;
2299 OP_SYMBOL (IC_RESULT (ic))->rematiCode = ic;
2300 OP_SYMBOL (IC_RESULT (ic))->usl.spillLoc = NULL;
2303 /* mark the pointer usages */
2304 if (POINTER_SET (ic))
2305 OP_SYMBOL (IC_RESULT (ic))->uptr = 1;
2307 if (POINTER_GET (ic))
2308 OP_SYMBOL (IC_LEFT (ic))->uptr = 1;
2312 /* if we are using a symbol on the stack
2313 then we should say ds390_ptrRegReq */
2314 if (ic->op == IFX && IS_SYMOP (IC_COND (ic)))
2315 ds390_ptrRegReq += ((OP_SYMBOL (IC_COND (ic))->onStack ||
2316 OP_SYMBOL (IC_COND (ic))->iaccess) ? 1 : 0);
2317 else if (ic->op == JUMPTABLE && IS_SYMOP (IC_JTCOND (ic)))
2318 ds390_ptrRegReq += ((OP_SYMBOL (IC_JTCOND (ic))->onStack ||
2319 OP_SYMBOL (IC_JTCOND (ic))->iaccess) ? 1 : 0);
2322 if (IS_SYMOP (IC_LEFT (ic)))
2323 ds390_ptrRegReq += ((OP_SYMBOL (IC_LEFT (ic))->onStack ||
2324 OP_SYMBOL (IC_LEFT (ic))->iaccess) ? 1 : 0);
2325 if (IS_SYMOP (IC_RIGHT (ic)))
2326 ds390_ptrRegReq += ((OP_SYMBOL (IC_RIGHT (ic))->onStack ||
2327 OP_SYMBOL (IC_RIGHT (ic))->iaccess) ? 1 : 0);
2328 if (IS_SYMOP (IC_RESULT (ic)))
2329 ds390_ptrRegReq += ((OP_SYMBOL (IC_RESULT (ic))->onStack ||
2330 OP_SYMBOL (IC_RESULT (ic))->iaccess) ? 1 : 0);
2335 /* if the condition of an if instruction
2336 is defined in the previous instruction then
2337 mark the itemp as a conditional */
2338 if ((IS_CONDITIONAL (ic) ||
2339 (IS_BITWISE_OP(ic) && isBitwiseOptimizable(ic))) &&
2340 ic->next && ic->next->op == IFX &&
2341 isOperandEqual (IC_RESULT (ic), IC_COND (ic->next)) &&
2342 OP_SYMBOL (IC_RESULT (ic))->liveTo <= ic->next->seq)
2345 OP_SYMBOL (IC_RESULT (ic))->regType = REG_CND;
2349 /* if the condition of an if instruction
2350 is defined in the previous instruction and
2351 this is the only usage then
2352 mark the itemp as a conditional */
2353 if ((IS_CONDITIONAL (ic) ||
2354 (IS_BITWISE_OP(ic) && isBitwiseOptimizable (ic))) &&
2355 ic->next && ic->next->op == IFX &&
2356 bitVectnBitsOn (OP_USES(IC_RESULT(ic)))==1 &&
2357 isOperandEqual (IC_RESULT (ic), IC_COND (ic->next)) &&
2358 OP_SYMBOL (IC_RESULT (ic))->liveTo <= ic->next->seq)
2360 OP_SYMBOL (IC_RESULT (ic))->regType = REG_CND;
2365 /* reduce for support function calls */
2366 if (ic->supportRtn || ic->op == '+' || ic->op == '-')
2367 packRegsForSupport (ic, ebp);
2369 /* some cases the redundant moves can
2370 can be eliminated for return statements */
2371 if ((ic->op == RETURN || ic->op == SEND) &&
2372 !isOperandInFarSpace (IC_LEFT (ic)) &&
2374 packRegsForOneuse (ic, IC_LEFT (ic), ebp);
2376 /* if pointer set & left has a size more than
2377 one and right is not in far space */
2378 if (POINTER_SET (ic) &&
2379 !isOperandInFarSpace (IC_RIGHT (ic)) &&
2380 !OP_SYMBOL (IC_RESULT (ic))->remat &&
2381 !IS_OP_RUONLY (IC_RIGHT (ic)) &&
2382 getSize (aggrToPtr (operandType (IC_RESULT (ic)), FALSE)) > 1)
2384 packRegsForOneuse (ic, IC_RESULT (ic), ebp);
2386 /* if pointer get */
2387 if (POINTER_GET (ic) &&
2388 !isOperandInFarSpace (IC_RESULT (ic)) &&
2389 !OP_SYMBOL (IC_LEFT (ic))->remat &&
2390 !IS_OP_RUONLY (IC_RESULT (ic)) &&
2391 getSize (aggrToPtr (operandType (IC_LEFT (ic)), FALSE)) > 1)
2393 packRegsForOneuse (ic, IC_LEFT (ic), ebp);
2396 /* if this is cast for intergral promotion then
2397 check if only use of the definition of the
2398 operand being casted/ if yes then replace
2399 the result of that arithmetic operation with
2400 this result and get rid of the cast */
2403 sym_link *fromType = operandType (IC_RIGHT (ic));
2404 sym_link *toType = operandType (IC_LEFT (ic));
2406 if (IS_INTEGRAL (fromType) && IS_INTEGRAL (toType) &&
2407 getSize (fromType) != getSize (toType) &&
2408 SPEC_USIGN (fromType) == SPEC_USIGN (toType))
2411 iCode *dic = packRegsForOneuse (ic, IC_RIGHT (ic), ebp);
2414 if (IS_ARITHMETIC_OP (dic))
2416 IC_RESULT (dic) = IC_RESULT (ic);
2417 remiCodeFromeBBlock (ebp, ic);
2418 hTabDeleteItem (&iCodehTab, ic->key, ic, DELETE_ITEM, NULL);
2419 OP_DEFS (IC_RESULT (dic)) = bitVectSetBit (OP_DEFS (IC_RESULT (dic)), dic->key);
2423 OP_SYMBOL (IC_RIGHT (ic))->ruonly = 0;
2429 /* if the type from and type to are the same
2430 then if this is the only use then packit */
2431 if (checkType (operandType (IC_RIGHT (ic)),
2432 operandType (IC_LEFT (ic))) == 1)
2434 iCode *dic = packRegsForOneuse (ic, IC_RIGHT (ic), ebp);
2437 IC_RESULT (dic) = IC_RESULT (ic);
2438 remiCodeFromeBBlock (ebp, ic);
2439 hTabDeleteItem (&iCodehTab, ic->key, ic, DELETE_ITEM, NULL);
2440 OP_DEFS (IC_RESULT (dic)) = bitVectSetBit (OP_DEFS (IC_RESULT (dic)), dic->key);
2448 iTempNN := (some variable in farspace) V1
2453 if (ic->op == IPUSH)
2455 packForPush (ic, ebp);
2459 /* pack registers for accumulator use, when the
2460 result of an arithmetic or bit wise operation
2461 has only one use, that use is immediately following
2462 the defintion and the using iCode has only one
2463 operand or has two operands but one is literal &
2464 the result of that operation is not on stack then
2465 we can leave the result of this operation in acc:b
2467 if ((IS_ARITHMETIC_OP (ic)
2469 || IS_BITWISE_OP (ic)
2471 || ic->op == LEFT_OP || ic->op == RIGHT_OP
2474 IS_ITEMP (IC_RESULT (ic)) &&
2475 getSize (operandType (IC_RESULT (ic))) <= 2)
2477 packRegsForAccUse (ic);
2482 /*-----------------------------------------------------------------*/
2483 /* assignRegisters - assigns registers to each live range as need */
2484 /*-----------------------------------------------------------------*/
2486 ds390_assignRegisters (eBBlock ** ebbs, int count)
2491 setToNull ((void *) &_G.funcrUsed);
2492 ds390_ptrRegReq = _G.stackExtend = _G.dataExtend = 0;
2493 /* if not register extentions then reduce number
2495 if (options.regExtend)
2500 /* change assignments this will remove some
2501 live ranges reducing some register pressure */
2502 for (i = 0; i < count; i++)
2503 packRegisters (ebbs[i]);
2505 if (options.dump_pack)
2506 dumpEbbsToFileExt (".dumppack", ebbs, count);
2508 /* first determine for each live range the number of
2509 registers & the type of registers required for each */
2512 /* and serially allocate registers */
2513 serialRegAssign (ebbs, count);
2515 /* if stack was extended then tell the user */
2518 /* werror(W_TOOMANY_SPILS,"stack", */
2519 /* _G.stackExtend,currFunc->name,""); */
2525 /* werror(W_TOOMANY_SPILS,"data space", */
2526 /* _G.dataExtend,currFunc->name,""); */
2530 /* after that create the register mask
2531 for each of the instruction */
2532 createRegMask (ebbs, count);
2534 /* redo that offsets for stacked automatic variables */
2535 redoStackOffsets ();
2537 if (options.dump_rassgn)
2538 dumpEbbsToFileExt (".dumprassgn", ebbs, count);
2540 /* do the overlaysegment stuff SDCCmem.c */
2541 doOverlays (ebbs, count);
2543 /* now get back the chain */
2544 ic = iCodeLabelOptimize (iCodeFromeBBlock (ebbs, count));
2549 /* free up any _G.stackSpil locations allocated */
2550 applyToSet (_G.stackSpil, deallocStackSpil);
2552 setToNull ((void **) &_G.stackSpil);
2553 setToNull ((void **) &_G.spiltSet);
2554 /* mark all registers as free */