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 SPEC_SCLS (sloc->etype) = options.model ? S_XDATA : S_DATA;
512 SPEC_EXTR (sloc->etype) = 0;
514 /* we don't allow it to be allocated`
515 onto the external stack since : so we
516 temporarily turn it off ; we also
517 turn off memory model to prevent
518 the spil from going to the external storage
519 and turn off overlaying
522 useXstack = options.useXstack;
523 model = options.model;
524 noOverlay = options.noOverlay;
525 options.noOverlay = 1;
527 /* options.model = options.useXstack = 0; */
531 options.useXstack = useXstack;
532 options.model = model;
533 options.noOverlay = noOverlay;
534 sloc->isref = 1; /* to prevent compiler warning */
536 /* if it is on the stack then update the stack */
537 if (IN_STACK (sloc->etype))
539 currFunc->stack += getSize (sloc->type);
540 _G.stackExtend += getSize (sloc->type);
543 _G.dataExtend += getSize (sloc->type);
545 /* add it to the _G.stackSpil set */
546 addSetHead (&_G.stackSpil, sloc);
547 sym->usl.spillLoc = sloc;
550 /* add it to the set of itempStack set
551 of the spill location */
552 addSetHead (&sloc->usl.itmpStack, sym);
556 /*-----------------------------------------------------------------*/
557 /* isSpiltOnStack - returns true if the spil location is on stack */
558 /*-----------------------------------------------------------------*/
560 isSpiltOnStack (symbol * sym)
570 /* if (sym->_G.stackSpil) */
573 if (!sym->usl.spillLoc)
576 etype = getSpec (sym->usl.spillLoc->type);
577 if (IN_STACK (etype))
583 /*-----------------------------------------------------------------*/
584 /* spillThis - spils a specific operand */
585 /*-----------------------------------------------------------------*/
587 spillThis (symbol * sym)
590 /* if this is rematerializable or has a spillLocation
591 we are okay, else we need to create a spillLocation
593 if (!(sym->remat || sym->usl.spillLoc))
594 createStackSpil (sym);
597 /* mark it has spilt & put it in the spilt set */
599 _G.spiltSet = bitVectSetBit (_G.spiltSet, sym->key);
601 bitVectUnSetBit (_G.regAssigned, sym->key);
603 for (i = 0; i < sym->nRegs; i++)
607 freeReg (sym->regs[i]);
611 /* if spilt on stack then free up r0 & r1
612 if they could have been assigned to some
614 if (!ds390_ptrRegReq && isSpiltOnStack (sym))
617 spillLRWithPtrReg (sym);
620 if (sym->usl.spillLoc && !sym->remat)
621 sym->usl.spillLoc->allocreq = 1;
625 /*-----------------------------------------------------------------*/
626 /* selectSpil - select a iTemp to spil : rather a simple procedure */
627 /*-----------------------------------------------------------------*/
629 selectSpil (iCode * ic, eBBlock * ebp, symbol * forSym)
631 bitVect *lrcs = NULL;
635 /* get the spillable live ranges */
636 lrcs = computeSpillable (ic);
638 /* get all live ranges that are rematerizable */
639 if ((selectS = liveRangesWith (lrcs, rematable, ebp, ic)))
642 /* return the least used of these */
643 return leastUsedLR (selectS);
646 /* get live ranges with spillLocations in direct space */
647 if ((selectS = liveRangesWith (lrcs, directSpilLoc, ebp, ic)))
649 sym = leastUsedLR (selectS);
650 strcpy (sym->rname, (sym->usl.spillLoc->rname[0] ?
651 sym->usl.spillLoc->rname :
652 sym->usl.spillLoc->name));
654 /* mark it as allocation required */
655 sym->usl.spillLoc->allocreq = 1;
659 /* if the symbol is local to the block then */
660 if (forSym->liveTo < ebp->lSeq)
663 /* check if there are any live ranges allocated
664 to registers that are not used in this block */
665 if (!_G.blockSpil && (selectS = liveRangesWith (lrcs, notUsedInBlock, ebp, ic)))
667 sym = leastUsedLR (selectS);
668 /* if this is not rematerializable */
677 /* check if there are any live ranges that not
678 used in the remainder of the block */
679 if (!_G.blockSpil && (selectS = liveRangesWith (lrcs, notUsedInRemaining, ebp, ic)))
681 sym = leastUsedLR (selectS);
694 /* find live ranges with spillocation && not used as pointers */
695 if ((selectS = liveRangesWith (lrcs, hasSpilLocnoUptr, ebp, ic)))
698 sym = leastUsedLR (selectS);
699 /* mark this as allocation required */
700 sym->usl.spillLoc->allocreq = 1;
704 /* find live ranges with spillocation */
705 if ((selectS = liveRangesWith (lrcs, hasSpilLoc, ebp, ic)))
708 sym = leastUsedLR (selectS);
709 sym->usl.spillLoc->allocreq = 1;
713 /* couldn't find then we need to create a spil
714 location on the stack , for which one? the least
716 if ((selectS = liveRangesWith (lrcs, noSpilLoc, ebp, ic)))
719 /* return a created spil location */
720 sym = createStackSpil (leastUsedLR (selectS));
721 sym->usl.spillLoc->allocreq = 1;
725 /* this is an extreme situation we will spill
726 this one : happens very rarely but it does happen */
732 /*-----------------------------------------------------------------*/
733 /* spilSomething - spil some variable & mark registers as free */
734 /*-----------------------------------------------------------------*/
736 spilSomething (iCode * ic, eBBlock * ebp, symbol * forSym)
741 /* get something we can spil */
742 ssym = selectSpil (ic, ebp, forSym);
744 /* mark it as spilt */
746 _G.spiltSet = bitVectSetBit (_G.spiltSet, ssym->key);
748 /* mark it as not register assigned &
749 take it away from the set */
750 bitVectUnSetBit (_G.regAssigned, ssym->key);
752 /* mark the registers as free */
753 for (i = 0; i < ssym->nRegs; i++)
755 freeReg (ssym->regs[i]);
757 /* if spilt on stack then free up r0 & r1
758 if they could have been assigned to as gprs */
759 if (!ds390_ptrRegReq && isSpiltOnStack (ssym))
762 spillLRWithPtrReg (ssym);
765 /* if this was a block level spil then insert push & pop
766 at the start & end of block respectively */
769 iCode *nic = newiCode (IPUSH, operandFromSymbol (ssym), NULL);
770 /* add push to the start of the block */
771 addiCodeToeBBlock (ebp, nic, (ebp->sch->op == LABEL ?
772 ebp->sch->next : ebp->sch));
773 nic = newiCode (IPOP, operandFromSymbol (ssym), NULL);
774 /* add pop to the end of the block */
775 addiCodeToeBBlock (ebp, nic, NULL);
778 /* if spilt because not used in the remainder of the
779 block then add a push before this instruction and
780 a pop at the end of the block */
781 if (ssym->remainSpil)
784 iCode *nic = newiCode (IPUSH, operandFromSymbol (ssym), NULL);
785 /* add push just before this instruction */
786 addiCodeToeBBlock (ebp, nic, ic);
788 nic = newiCode (IPOP, operandFromSymbol (ssym), NULL);
789 /* add pop to the end of the block */
790 addiCodeToeBBlock (ebp, nic, NULL);
799 /*-----------------------------------------------------------------*/
800 /* getRegPtr - will try for PTR if not a GPR type if not spil */
801 /*-----------------------------------------------------------------*/
803 getRegPtr (iCode * ic, eBBlock * ebp, symbol * sym)
808 /* try for a ptr type */
809 if ((reg = allocReg (REG_PTR)))
812 /* try for gpr type */
813 if ((reg = allocReg (REG_GPR)))
816 /* we have to spil */
817 if (!spilSomething (ic, ebp, sym))
820 /* this looks like an infinite loop but
821 in really selectSpil will abort */
825 /*-----------------------------------------------------------------*/
826 /* getRegGpr - will try for GPR if not spil */
827 /*-----------------------------------------------------------------*/
829 getRegGpr (iCode * ic, eBBlock * ebp, symbol * sym)
834 /* try for gpr type */
835 if ((reg = allocReg (REG_GPR)))
838 if (!ds390_ptrRegReq)
839 if ((reg = allocReg (REG_PTR)))
842 /* we have to spil */
843 if (!spilSomething (ic, ebp, sym))
846 /* this looks like an infinite loop but
847 in really selectSpil will abort */
851 /*-----------------------------------------------------------------*/
852 /* symHasReg - symbol has a given register */
853 /*-----------------------------------------------------------------*/
855 symHasReg (symbol * sym, regs * reg)
859 for (i = 0; i < sym->nRegs; i++)
860 if (sym->regs[i] == reg)
866 /*-----------------------------------------------------------------*/
867 /* deassignLRs - check the live to and if they have registers & are */
868 /* not spilt then free up the registers */
869 /*-----------------------------------------------------------------*/
871 deassignLRs (iCode * ic, eBBlock * ebp)
877 for (sym = hTabFirstItem (liveRanges, &k); sym;
878 sym = hTabNextItem (liveRanges, &k))
882 /* if it does not end here */
883 if (sym->liveTo > ic->seq)
886 /* if it was spilt on stack then we can
887 mark the stack spil location as free */
892 sym->usl.spillLoc->isFree = 1;
898 if (!bitVectBitValue (_G.regAssigned, sym->key))
901 /* special case check if this is an IFX &
902 the privious one was a pop and the
903 previous one was not spilt then keep track
905 if (ic->op == IFX && ic->prev &&
906 ic->prev->op == IPOP &&
907 !ic->prev->parmPush &&
908 !OP_SYMBOL (IC_LEFT (ic->prev))->isspilt)
909 psym = OP_SYMBOL (IC_LEFT (ic->prev));
915 bitVectUnSetBit (_G.regAssigned, sym->key);
917 /* if the result of this one needs registers
918 and does not have it then assign it right
920 if (IC_RESULT (ic) &&
921 !(SKIP_IC2 (ic) || /* not a special icode */
922 ic->op == JUMPTABLE ||
928 (result = OP_SYMBOL (IC_RESULT (ic))) && /* has a result */
929 result->liveTo > ic->seq && /* and will live beyond this */
930 result->liveTo <= ebp->lSeq && /* does not go beyond this block */
931 result->regType == sym->regType && /* same register types */
932 result->nRegs && /* which needs registers */
933 !result->isspilt && /* and does not already have them */
935 !bitVectBitValue (_G.regAssigned, result->key) &&
936 /* the number of free regs + number of regs in this LR
937 can accomodate the what result Needs */
938 ((nfreeRegsType (result->regType) +
939 sym->nRegs) >= result->nRegs)
943 for (i = 0; i < result->nRegs; i++)
945 result->regs[i] = sym->regs[i];
947 result->regs[i] = getRegGpr (ic, ebp, result);
949 _G.regAssigned = bitVectSetBit (_G.regAssigned, result->key);
953 /* free the remaining */
954 for (; i < sym->nRegs; i++)
958 if (!symHasReg (psym, sym->regs[i]))
959 freeReg (sym->regs[i]);
962 freeReg (sym->regs[i]);
969 /*-----------------------------------------------------------------*/
970 /* reassignLR - reassign this to registers */
971 /*-----------------------------------------------------------------*/
973 reassignLR (operand * op)
975 symbol *sym = OP_SYMBOL (op);
978 /* not spilt any more */
979 sym->isspilt = sym->blockSpil = sym->remainSpil = 0;
980 bitVectUnSetBit (_G.spiltSet, sym->key);
982 _G.regAssigned = bitVectSetBit (_G.regAssigned, sym->key);
986 for (i = 0; i < sym->nRegs; i++)
987 sym->regs[i]->isFree = 0;
990 /*-----------------------------------------------------------------*/
991 /* willCauseSpill - determines if allocating will cause a spill */
992 /*-----------------------------------------------------------------*/
994 willCauseSpill (int nr, int rt)
996 /* first check if there are any avlb registers
997 of te type required */
1000 /* special case for pointer type
1001 if pointer type not avlb then
1002 check for type gpr */
1003 if (nFreeRegs (rt) >= nr)
1005 if (nFreeRegs (REG_GPR) >= nr)
1010 if (ds390_ptrRegReq)
1012 if (nFreeRegs (rt) >= nr)
1017 if (nFreeRegs (REG_PTR) +
1018 nFreeRegs (REG_GPR) >= nr)
1023 /* it will cause a spil */
1027 /*-----------------------------------------------------------------*/
1028 /* positionRegs - the allocator can allocate same registers to res- */
1029 /* ult and operand, if this happens make sure they are in the same */
1030 /* position as the operand otherwise chaos results */
1031 /*-----------------------------------------------------------------*/
1033 positionRegs (symbol * result, symbol * opsym, int lineno)
1035 int count = min (result->nRegs, opsym->nRegs);
1036 int i, j = 0, shared = 0;
1038 /* if the result has been spilt then cannot share */
1043 /* first make sure that they actually share */
1044 for (i = 0; i < count; i++)
1046 for (j = 0; j < count; j++)
1048 if (result->regs[i] == opsym->regs[j] && i != j)
1058 regs *tmp = result->regs[i];
1059 result->regs[i] = result->regs[j];
1060 result->regs[j] = tmp;
1065 /*-----------------------------------------------------------------*/
1066 /* serialRegAssign - serially allocate registers to the variables */
1067 /*-----------------------------------------------------------------*/
1069 serialRegAssign (eBBlock ** ebbs, int count)
1073 /* for all blocks */
1074 for (i = 0; i < count; i++)
1079 if (ebbs[i]->noPath &&
1080 (ebbs[i]->entryLabel != entryLabel &&
1081 ebbs[i]->entryLabel != returnLabel))
1084 /* of all instructions do */
1085 for (ic = ebbs[i]->sch; ic; ic = ic->next)
1088 /* if this is an ipop that means some live
1089 range will have to be assigned again */
1091 reassignLR (IC_LEFT (ic));
1093 /* if result is present && is a true symbol */
1094 if (IC_RESULT (ic) && ic->op != IFX &&
1095 IS_TRUE_SYMOP (IC_RESULT (ic)))
1096 OP_SYMBOL (IC_RESULT (ic))->allocreq = 1;
1098 /* take away registers from live
1099 ranges that end at this instruction */
1100 deassignLRs (ic, ebbs[i]);
1102 /* some don't need registers */
1103 if (SKIP_IC2 (ic) ||
1104 ic->op == JUMPTABLE ||
1108 (IC_RESULT (ic) && POINTER_SET (ic)))
1111 /* now we need to allocate registers
1112 only for the result */
1115 symbol *sym = OP_SYMBOL (IC_RESULT (ic));
1121 /* if it does not need or is spilt
1122 or is already assigned to registers
1123 or will not live beyond this instructions */
1126 bitVectBitValue (_G.regAssigned, sym->key) ||
1127 sym->liveTo <= ic->seq)
1130 /* if some liverange has been spilt at the block level
1131 and this one live beyond this block then spil this
1133 if (_G.blockSpil && sym->liveTo > ebbs[i]->lSeq)
1138 /* if trying to allocate this will cause
1139 a spill and there is nothing to spill
1140 or this one is rematerializable then
1142 willCS = willCauseSpill (sym->nRegs, sym->regType);
1143 spillable = computeSpillable (ic);
1145 (willCS && bitVectIsZero (spillable)))
1153 /* if it has a spillocation & is used less than
1154 all other live ranges then spill this */
1156 if (sym->usl.spillLoc) {
1157 symbol *leastUsed = leastUsedLR (liveRangesWith (spillable,
1158 allLRs, ebbs[i], ic));
1159 if (leastUsed && leastUsed->used > sym->used) {
1164 /* if none of the liveRanges have a spillLocation then better
1165 to spill this one than anything else already assigned to registers */
1166 if (liveRangesWith(spillable,noSpilLoc,ebbs[i],ic)) {
1173 /* if we need ptr regs for the right side
1175 if (POINTER_GET (ic) && IS_SYMOP (IC_LEFT (ic))
1176 && getSize (OP_SYMBOL (IC_LEFT (ic))->type)
1177 <= (unsigned) PTRSIZE)
1182 /* else we assign registers to it */
1183 _G.regAssigned = bitVectSetBit (_G.regAssigned, sym->key);
1185 for (j = 0; j < sym->nRegs; j++)
1187 if (sym->regType == REG_PTR)
1188 sym->regs[j] = getRegPtr (ic, ebbs[i], sym);
1190 sym->regs[j] = getRegGpr (ic, ebbs[i], sym);
1192 /* if the allocation falied which means
1193 this was spilt then break */
1197 /* if it shares registers with operands make sure
1198 that they are in the same position */
1199 if (IC_LEFT (ic) && IS_SYMOP (IC_LEFT (ic)) &&
1200 OP_SYMBOL (IC_LEFT (ic))->nRegs && ic->op != '=')
1201 positionRegs (OP_SYMBOL (IC_RESULT (ic)),
1202 OP_SYMBOL (IC_LEFT (ic)), ic->lineno);
1203 /* do the same for the right operand */
1204 if (IC_RIGHT (ic) && IS_SYMOP (IC_RIGHT (ic)) &&
1205 OP_SYMBOL (IC_RIGHT (ic))->nRegs)
1206 positionRegs (OP_SYMBOL (IC_RESULT (ic)),
1207 OP_SYMBOL (IC_RIGHT (ic)), ic->lineno);
1220 /*-----------------------------------------------------------------*/
1221 /* rUmaskForOp :- returns register mask for an operand */
1222 /*-----------------------------------------------------------------*/
1224 rUmaskForOp (operand * op)
1230 /* only temporaries are assigned registers */
1234 sym = OP_SYMBOL (op);
1236 /* if spilt or no registers assigned to it
1238 if (sym->isspilt || !sym->nRegs)
1241 rumask = newBitVect (ds390_nRegs);
1243 for (j = 0; j < sym->nRegs; j++)
1245 rumask = bitVectSetBit (rumask,
1246 sym->regs[j]->rIdx);
1252 /*-----------------------------------------------------------------*/
1253 /* regsUsedIniCode :- returns bit vector of registers used in iCode */
1254 /*-----------------------------------------------------------------*/
1256 regsUsedIniCode (iCode * ic)
1258 bitVect *rmask = newBitVect (ds390_nRegs);
1260 /* do the special cases first */
1263 rmask = bitVectUnion (rmask,
1264 rUmaskForOp (IC_COND (ic)));
1268 /* for the jumptable */
1269 if (ic->op == JUMPTABLE)
1271 rmask = bitVectUnion (rmask,
1272 rUmaskForOp (IC_JTCOND (ic)));
1277 /* of all other cases */
1279 rmask = bitVectUnion (rmask,
1280 rUmaskForOp (IC_LEFT (ic)));
1284 rmask = bitVectUnion (rmask,
1285 rUmaskForOp (IC_RIGHT (ic)));
1288 rmask = bitVectUnion (rmask,
1289 rUmaskForOp (IC_RESULT (ic)));
1295 /*-----------------------------------------------------------------*/
1296 /* createRegMask - for each instruction will determine the regsUsed */
1297 /*-----------------------------------------------------------------*/
1299 createRegMask (eBBlock ** ebbs, int count)
1303 /* for all blocks */
1304 for (i = 0; i < count; i++)
1308 if (ebbs[i]->noPath &&
1309 (ebbs[i]->entryLabel != entryLabel &&
1310 ebbs[i]->entryLabel != returnLabel))
1313 /* for all instructions */
1314 for (ic = ebbs[i]->sch; ic; ic = ic->next)
1319 if (SKIP_IC2 (ic) || !ic->rlive)
1322 /* first mark the registers used in this
1324 ic->rUsed = regsUsedIniCode (ic);
1325 _G.funcrUsed = bitVectUnion (_G.funcrUsed, ic->rUsed);
1327 /* now create the register mask for those
1328 registers that are in use : this is a
1329 super set of ic->rUsed */
1330 ic->rMask = newBitVect (ds390_nRegs + 1);
1332 /* for all live Ranges alive at this point */
1333 for (j = 1; j < ic->rlive->size; j++)
1338 /* if not alive then continue */
1339 if (!bitVectBitValue (ic->rlive, j))
1342 /* find the live range we are interested in */
1343 if (!(sym = hTabItemWithKey (liveRanges, j)))
1345 werror (E_INTERNAL_ERROR, __FILE__, __LINE__,
1346 "createRegMask cannot find live range");
1350 /* if no register assigned to it */
1351 if (!sym->nRegs || sym->isspilt)
1354 /* for all the registers allocated to it */
1355 for (k = 0; k < sym->nRegs; k++)
1358 bitVectSetBit (ic->rMask, sym->regs[k]->rIdx);
1364 /*-----------------------------------------------------------------*/
1365 /* rematStr - returns the rematerialized string for a remat var */
1366 /*-----------------------------------------------------------------*/
1368 rematStr (symbol * sym)
1371 iCode *ic = sym->rematiCode;
1376 /* if plus or minus print the right hand side */
1377 if (ic->op == '+' || ic->op == '-')
1379 sprintf (s, "0x%04x %c ", (int) operandLitValue (IC_RIGHT (ic)),
1382 ic = OP_SYMBOL (IC_LEFT (ic))->rematiCode;
1386 /* we reached the end */
1387 sprintf (s, "%s", OP_SYMBOL (IC_LEFT (ic))->rname);
1394 /*-----------------------------------------------------------------*/
1395 /* regTypeNum - computes the type & number of registers required */
1396 /*-----------------------------------------------------------------*/
1404 /* for each live range do */
1405 for (sym = hTabFirstItem (liveRanges, &k); sym;
1406 sym = hTabNextItem (liveRanges, &k))
1409 /* if used zero times then no registers needed */
1410 if ((sym->liveTo - sym->liveFrom) == 0)
1414 /* if the live range is a temporary */
1418 /* if the type is marked as a conditional */
1419 if (sym->regType == REG_CND)
1422 /* if used in return only then we don't
1424 if (sym->ruonly || sym->accuse)
1426 if (IS_AGGREGATE (sym->type) || sym->isptr)
1427 sym->type = aggrToPtr (sym->type, FALSE);
1431 /* if the symbol has only one definition &
1432 that definition is a get_pointer and the
1433 pointer we are getting is rematerializable and
1436 if (bitVectnBitsOn (sym->defs) == 1 &&
1437 (ic = hTabItemWithKey (iCodehTab,
1438 bitVectFirstBit (sym->defs))) &&
1440 !IS_BITVAR (sym->etype))
1444 /* if remat in data space */
1445 if (OP_SYMBOL (IC_LEFT (ic))->remat &&
1447 DCL_TYPE (aggrToPtr (sym->type, FALSE)) == POINTER)
1450 /* create a psuedo symbol & force a spil */
1451 symbol *psym = newSymbol (rematStr (OP_SYMBOL (IC_LEFT (ic))), 1);
1452 psym->type = sym->type;
1453 psym->etype = sym->etype;
1454 strcpy (psym->rname, psym->name);
1456 sym->usl.spillLoc = psym;
1460 /* if in data space or idata space then try to
1461 allocate pointer register */
1465 /* if not then we require registers */
1466 sym->nRegs = ((IS_AGGREGATE (sym->type) || sym->isptr) ?
1467 getSize (sym->type = aggrToPtr (sym->type, FALSE)) :
1468 getSize (sym->type));
1472 fprintf (stderr, "allocated more than 4 or 0 registers for type ");
1473 printTypeChain (sym->type, stderr);
1474 fprintf (stderr, "\n");
1477 /* determine the type of register required */
1478 if (sym->nRegs == 1 &&
1479 IS_PTR (sym->type) &&
1481 sym->regType = REG_PTR;
1483 sym->regType = REG_GPR;
1487 /* for the first run we don't provide */
1488 /* registers for true symbols we will */
1489 /* see how things go */
1495 /*-----------------------------------------------------------------*/
1496 /* freeAllRegs - mark all registers as free */
1497 /*-----------------------------------------------------------------*/
1503 for (i = 0; i < ds390_nRegs; i++)
1504 regs390[i].isFree = 1;
1507 /*-----------------------------------------------------------------*/
1508 /* deallocStackSpil - this will set the stack pointer back */
1509 /*-----------------------------------------------------------------*/
1511 DEFSETFUNC (deallocStackSpil)
1519 /*-----------------------------------------------------------------*/
1520 /* farSpacePackable - returns the packable icode for far variables */
1521 /*-----------------------------------------------------------------*/
1523 farSpacePackable (iCode * ic)
1527 /* go thru till we find a definition for the
1528 symbol on the right */
1529 for (dic = ic->prev; dic; dic = dic->prev)
1532 /* if the definition is a call then no */
1533 if ((dic->op == CALL || dic->op == PCALL) &&
1534 IC_RESULT (dic)->key == IC_RIGHT (ic)->key)
1539 /* if shift by unknown amount then not */
1540 if ((dic->op == LEFT_OP || dic->op == RIGHT_OP) &&
1541 IC_RESULT (dic)->key == IC_RIGHT (ic)->key)
1544 /* if pointer get and size > 1 */
1545 if (POINTER_GET (dic) &&
1546 getSize (aggrToPtr (operandType (IC_LEFT (dic)), FALSE)) > 1)
1549 if (POINTER_SET (dic) &&
1550 getSize (aggrToPtr (operandType (IC_RESULT (dic)), FALSE)) > 1)
1553 /* if any three is a true symbol in far space */
1554 if (IC_RESULT (dic) &&
1555 IS_TRUE_SYMOP (IC_RESULT (dic)) &&
1556 isOperandInFarSpace (IC_RESULT (dic)))
1559 if (IC_RIGHT (dic) &&
1560 IS_TRUE_SYMOP (IC_RIGHT (dic)) &&
1561 isOperandInFarSpace (IC_RIGHT (dic)) &&
1562 !isOperandEqual (IC_RIGHT (dic), IC_RESULT (ic)))
1565 if (IC_LEFT (dic) &&
1566 IS_TRUE_SYMOP (IC_LEFT (dic)) &&
1567 isOperandInFarSpace (IC_LEFT (dic)) &&
1568 !isOperandEqual (IC_LEFT (dic), IC_RESULT (ic)))
1571 if (isOperandEqual (IC_RIGHT (ic), IC_RESULT (dic)))
1573 if ((dic->op == LEFT_OP ||
1574 dic->op == RIGHT_OP ||
1576 IS_OP_LITERAL (IC_RIGHT (dic)))
1586 /*-----------------------------------------------------------------*/
1587 /* packRegsForAssign - register reduction for assignment */
1588 /*-----------------------------------------------------------------*/
1590 packRegsForAssign (iCode * ic, eBBlock * ebp)
1594 if (!IS_ITEMP (IC_RIGHT (ic)) ||
1595 OP_SYMBOL (IC_RIGHT (ic))->isind ||
1596 OP_LIVETO (IC_RIGHT (ic)) > ic->seq)
1601 /* if the true symbol is defined in far space or on stack
1602 then we should not since this will increase register pressure */
1604 if (isOperandInFarSpace (IC_RESULT (ic)))
1606 if ((dic = farSpacePackable (ic)))
1612 if (isOperandInFarSpace(IC_RESULT(ic)) && !farSpacePackable(ic)) {
1617 /* find the definition of iTempNN scanning backwards if we find a
1618 a use of the true symbol in before we find the definition then
1620 for (dic = ic->prev; dic; dic = dic->prev)
1622 /* if there is a function call then don't pack it */
1623 if ((dic->op == CALL || dic->op == PCALL))
1632 if (IS_TRUE_SYMOP (IC_RESULT (dic)) &&
1633 IS_OP_VOLATILE (IC_RESULT (dic)))
1639 if (IS_SYMOP (IC_RESULT (dic)) &&
1640 IC_RESULT (dic)->key == IC_RIGHT (ic)->key)
1642 if (POINTER_SET (dic))
1648 if (IS_SYMOP (IC_RIGHT (dic)) &&
1649 (IC_RIGHT (dic)->key == IC_RESULT (ic)->key ||
1650 IC_RIGHT (dic)->key == IC_RIGHT (ic)->key))
1656 if (IS_SYMOP (IC_LEFT (dic)) &&
1657 (IC_LEFT (dic)->key == IC_RESULT (ic)->key ||
1658 IC_LEFT (dic)->key == IC_RIGHT (ic)->key))
1664 if (POINTER_SET (dic) &&
1665 IC_RESULT (dic)->key == IC_RESULT (ic)->key)
1673 return 0; /* did not find */
1675 /* if the result is on stack or iaccess then it must be
1676 the same atleast one of the operands */
1677 if (OP_SYMBOL (IC_RESULT (ic))->onStack ||
1678 OP_SYMBOL (IC_RESULT (ic))->iaccess)
1681 /* the operation has only one symbol
1682 operator then we can pack */
1683 if ((IC_LEFT (dic) && !IS_SYMOP (IC_LEFT (dic))) ||
1684 (IC_RIGHT (dic) && !IS_SYMOP (IC_RIGHT (dic))))
1687 if (!((IC_LEFT (dic) &&
1688 IC_RESULT (ic)->key == IC_LEFT (dic)->key) ||
1690 IC_RESULT (ic)->key == IC_RIGHT (dic)->key)))
1694 /* found the definition */
1695 /* replace the result with the result of */
1696 /* this assignment and remove this assignment */
1697 IC_RESULT (dic) = IC_RESULT (ic);
1699 if (IS_ITEMP (IC_RESULT (dic)) && OP_SYMBOL (IC_RESULT (dic))->liveFrom > dic->seq)
1701 OP_SYMBOL (IC_RESULT (dic))->liveFrom = dic->seq;
1703 /* delete from liverange table also
1704 delete from all the points inbetween and the new
1706 for (sic = dic; sic != ic; sic = sic->next)
1708 bitVectUnSetBit (sic->rlive, IC_RESULT (ic)->key);
1709 if (IS_ITEMP (IC_RESULT (dic)))
1710 bitVectSetBit (sic->rlive, IC_RESULT (dic)->key);
1713 remiCodeFromeBBlock (ebp, ic);
1714 hTabDeleteItem (&iCodehTab, ic->key, ic, DELETE_ITEM, NULL);
1715 OP_DEFS (IC_RESULT (dic)) = bitVectSetBit (OP_DEFS (IC_RESULT (dic)), dic->key);
1720 /*-----------------------------------------------------------------*/
1721 /* findAssignToSym : scanning backwards looks for first assig found */
1722 /*-----------------------------------------------------------------*/
1724 findAssignToSym (operand * op, iCode * ic)
1728 for (dic = ic->prev; dic; dic = dic->prev)
1731 /* if definition by assignment */
1732 if (dic->op == '=' &&
1733 !POINTER_SET (dic) &&
1734 IC_RESULT (dic)->key == op->key
1735 /* && IS_TRUE_SYMOP(IC_RIGHT(dic)) */
1739 /* we are interested only if defined in far space */
1740 /* or in stack space in case of + & - */
1742 /* if assigned to a non-symbol then return
1744 if (!IS_SYMOP (IC_RIGHT (dic)))
1747 /* if the symbol is in far space then
1749 if (isOperandInFarSpace (IC_RIGHT (dic)))
1752 /* for + & - operations make sure that
1753 if it is on the stack it is the same
1754 as one of the three operands */
1755 if ((ic->op == '+' || ic->op == '-') &&
1756 OP_SYMBOL (IC_RIGHT (dic))->onStack)
1759 if (IC_RESULT (ic)->key != IC_RIGHT (dic)->key &&
1760 IC_LEFT (ic)->key != IC_RIGHT (dic)->key &&
1761 IC_RIGHT (ic)->key != IC_RIGHT (dic)->key)
1769 /* if we find an usage then we cannot delete it */
1770 if (IC_LEFT (dic) && IC_LEFT (dic)->key == op->key)
1773 if (IC_RIGHT (dic) && IC_RIGHT (dic)->key == op->key)
1776 if (POINTER_SET (dic) && IC_RESULT (dic)->key == op->key)
1780 /* now make sure that the right side of dic
1781 is not defined between ic & dic */
1784 iCode *sic = dic->next;
1786 for (; sic != ic; sic = sic->next)
1787 if (IC_RESULT (sic) &&
1788 IC_RESULT (sic)->key == IC_RIGHT (dic)->key)
1797 /*-----------------------------------------------------------------*/
1798 /* packRegsForSupport :- reduce some registers for support calls */
1799 /*-----------------------------------------------------------------*/
1801 packRegsForSupport (iCode * ic, eBBlock * ebp)
1804 /* for the left & right operand :- look to see if the
1805 left was assigned a true symbol in far space in that
1806 case replace them */
1807 if (IS_ITEMP (IC_LEFT (ic)) &&
1808 OP_SYMBOL (IC_LEFT (ic))->liveTo <= ic->seq)
1810 iCode *dic = findAssignToSym (IC_LEFT (ic), ic);
1816 /* found it we need to remove it from the
1818 for (sic = dic; sic != ic; sic = sic->next)
1819 bitVectUnSetBit (sic->rlive, IC_LEFT (ic)->key);
1821 IC_LEFT (ic)->operand.symOperand =
1822 IC_RIGHT (dic)->operand.symOperand;
1823 IC_LEFT (ic)->key = IC_RIGHT (dic)->operand.symOperand->key;
1824 remiCodeFromeBBlock (ebp, dic);
1825 hTabDeleteItem (&iCodehTab, dic->key, dic, DELETE_ITEM, NULL);
1829 /* do the same for the right operand */
1832 IS_ITEMP (IC_RIGHT (ic)) &&
1833 OP_SYMBOL (IC_RIGHT (ic))->liveTo <= ic->seq)
1835 iCode *dic = findAssignToSym (IC_RIGHT (ic), ic);
1841 /* if this is a subtraction & the result
1842 is a true symbol in far space then don't pack */
1843 if (ic->op == '-' && IS_TRUE_SYMOP (IC_RESULT (dic)))
1845 sym_link *etype = getSpec (operandType (IC_RESULT (dic)));
1846 if (IN_FARSPACE (SPEC_OCLS (etype)))
1849 /* found it we need to remove it from the
1851 for (sic = dic; sic != ic; sic = sic->next)
1852 bitVectUnSetBit (sic->rlive, IC_RIGHT (ic)->key);
1854 IC_RIGHT (ic)->operand.symOperand =
1855 IC_RIGHT (dic)->operand.symOperand;
1856 IC_RIGHT (ic)->key = IC_RIGHT (dic)->operand.symOperand->key;
1858 remiCodeFromeBBlock (ebp, dic);
1859 hTabDeleteItem (&iCodehTab, dic->key, dic, DELETE_ITEM, NULL);
1866 #define IS_OP_RUONLY(x) (x && IS_SYMOP(x) && OP_SYMBOL(x)->ruonly)
1869 /*-----------------------------------------------------------------*/
1870 /* packRegsForOneuse : - will reduce some registers for single Use */
1871 /*-----------------------------------------------------------------*/
1873 packRegsForOneuse (iCode * ic, operand * op, eBBlock * ebp)
1877 /* I can't figure out how to make this safe yet. */
1878 if ((int)ic+(int)op+(int)ebp) {
1889 /* if returning a literal then do nothing */
1893 /* only upto 2 bytes since we cannot predict
1894 the usage of b, & acc */
1895 if (getSize (operandType (op)) > (fReturnSizeDS390 - 2) &&
1898 !POINTER_SET (ic) &&
1902 /* this routine will mark the a symbol as used in one
1903 instruction use only && if the defintion is local
1904 (ie. within the basic block) && has only one definition &&
1905 that definiion is either a return value from a
1906 function or does not contain any variables in
1908 uses = bitVectCopy (OP_USES (op));
1909 bitVectUnSetBit (uses, ic->key); /* take away this iCode */
1910 if (!bitVectIsZero (uses)) /* has other uses */
1913 /* if it has only one defintion */
1914 if (bitVectnBitsOn (OP_DEFS (op)) > 1)
1915 return NULL; /* has more than one definition */
1917 /* get the that definition */
1919 hTabItemWithKey (iCodehTab,
1920 bitVectFirstBit (OP_DEFS (op)))))
1923 /* if that only usage is a cast */
1924 if (dic->op == CAST) {
1925 /* to a bigger type */
1926 if (getSize(OP_SYM_TYPE(IC_RESULT(dic))) >
1927 getSize(OP_SYM_TYPE(IC_RIGHT(dic)))) {
1928 /* than we can not, since we cannot predict the usage of b & acc */
1933 /* found the definition now check if it is local */
1934 if (dic->seq < ebp->fSeq ||
1935 dic->seq > ebp->lSeq)
1936 return NULL; /* non-local */
1938 /* now check if it is the return from
1940 if (dic->op == CALL || dic->op == PCALL)
1942 if (ic->op != SEND && ic->op != RETURN)
1944 OP_SYMBOL (op)->ruonly = 1;
1951 /* otherwise check that the definition does
1952 not contain any symbols in far space */
1953 if (isOperandInFarSpace (IC_LEFT (dic)) ||
1954 isOperandInFarSpace (IC_RIGHT (dic)) ||
1955 IS_OP_RUONLY (IC_LEFT (ic)) ||
1956 IS_OP_RUONLY (IC_RIGHT (ic)))
1961 /* if pointer set then make sure the pointer
1963 if (POINTER_SET (dic) &&
1964 !IS_DATA_PTR (aggrToPtr (operandType (IC_RESULT (dic)), FALSE)))
1967 if (POINTER_GET (dic) &&
1968 !IS_DATA_PTR (aggrToPtr (operandType (IC_LEFT (dic)), FALSE)))
1973 /* also make sure the intervenening instructions
1974 don't have any thing in far space */
1975 for (dic = dic->next; dic && dic != ic; dic = dic->next)
1978 /* if there is an intervening function call then no */
1979 if (dic->op == CALL || dic->op == PCALL)
1981 /* if pointer set then make sure the pointer
1983 if (POINTER_SET (dic) &&
1984 !IS_DATA_PTR (aggrToPtr (operandType (IC_RESULT (dic)), FALSE)))
1987 if (POINTER_GET (dic) &&
1988 !IS_DATA_PTR (aggrToPtr (operandType (IC_LEFT (dic)), FALSE)))
1991 /* if address of & the result is remat the okay */
1992 if (dic->op == ADDRESS_OF &&
1993 OP_SYMBOL (IC_RESULT (dic))->remat)
1996 /* if operand has size of three or more & this
1997 operation is a '*','/' or '%' then 'b' may
1999 if ((dic->op == '%' || dic->op == '/' || dic->op == '*') &&
2000 getSize (operandType (op)) >= 3)
2003 /* if left or right or result is in far space */
2004 if (isOperandInFarSpace (IC_LEFT (dic)) ||
2005 isOperandInFarSpace (IC_RIGHT (dic)) ||
2006 isOperandInFarSpace (IC_RESULT (dic)) ||
2007 IS_OP_RUONLY (IC_LEFT (dic)) ||
2008 IS_OP_RUONLY (IC_RIGHT (dic)) ||
2009 IS_OP_RUONLY (IC_RESULT (dic)))
2015 OP_SYMBOL (op)->ruonly = 1;
2020 /*-----------------------------------------------------------------*/
2021 /* isBitwiseOptimizable - requirements of JEAN LOUIS VERN */
2022 /*-----------------------------------------------------------------*/
2024 isBitwiseOptimizable (iCode * ic)
2026 sym_link *ltype = getSpec (operandType (IC_LEFT (ic)));
2027 sym_link *rtype = getSpec (operandType (IC_RIGHT (ic)));
2029 /* bitwise operations are considered optimizable
2030 under the following conditions (Jean-Louis VERN)
2042 if ( IS_LITERAL (rtype) ||
2043 (IS_BITVAR (ltype) && IN_BITSPACE (SPEC_OCLS (ltype))))
2049 /*-----------------------------------------------------------------*/
2050 /* packRegsForAccUse - pack registers for acc use */
2051 /*-----------------------------------------------------------------*/
2053 packRegsForAccUse (iCode * ic)
2057 /* if + or - then it has to be one byte result */
2058 if ((ic->op == '+' || ic->op == '-')
2059 && getSize (operandType (IC_RESULT (ic))) > 1)
2062 /* if shift operation make sure right side is not a literal */
2063 if (ic->op == RIGHT_OP &&
2064 (isOperandLiteral (IC_RIGHT (ic)) ||
2065 getSize (operandType (IC_RESULT (ic))) > 1))
2068 if (ic->op == LEFT_OP &&
2069 (isOperandLiteral (IC_RIGHT (ic)) ||
2070 getSize (operandType (IC_RESULT (ic))) > 1))
2073 if (IS_BITWISE_OP (ic) &&
2074 getSize (operandType (IC_RESULT (ic))) > 1)
2078 /* has only one definition */
2079 if (bitVectnBitsOn (OP_DEFS (IC_RESULT (ic))) > 1)
2082 /* has only one use */
2083 if (bitVectnBitsOn (OP_USES (IC_RESULT (ic))) > 1)
2086 /* and the usage immediately follows this iCode */
2087 if (!(uic = hTabItemWithKey (iCodehTab,
2088 bitVectFirstBit (OP_USES (IC_RESULT (ic))))))
2091 if (ic->next != uic)
2094 /* if it is a conditional branch then we definitely can */
2098 if (uic->op == JUMPTABLE)
2101 /* if the usage is not is an assignment
2102 or an arithmetic / bitwise / shift operation then not */
2103 if (POINTER_SET (uic) &&
2104 getSize (aggrToPtr (operandType (IC_RESULT (uic)), FALSE)) > 1)
2107 if (uic->op != '=' &&
2108 !IS_ARITHMETIC_OP (uic) &&
2109 !IS_BITWISE_OP (uic) &&
2110 uic->op != LEFT_OP &&
2111 uic->op != RIGHT_OP)
2114 /* if used in ^ operation then make sure right is not a
2116 if (uic->op == '^' && isOperandLiteral (IC_RIGHT (uic)))
2119 /* if shift operation make sure right side is not a literal */
2120 if (uic->op == RIGHT_OP &&
2121 (isOperandLiteral (IC_RIGHT (uic)) ||
2122 getSize (operandType (IC_RESULT (uic))) > 1))
2125 if (uic->op == LEFT_OP &&
2126 (isOperandLiteral (IC_RIGHT (uic)) ||
2127 getSize (operandType (IC_RESULT (uic))) > 1))
2130 /* make sure that the result of this icode is not on the
2131 stack, since acc is used to compute stack offset */
2132 if (IS_TRUE_SYMOP (IC_RESULT (uic)) &&
2133 OP_SYMBOL (IC_RESULT (uic))->onStack)
2136 /* if either one of them in far space then we cannot */
2137 if ((IS_TRUE_SYMOP (IC_LEFT (uic)) &&
2138 isOperandInFarSpace (IC_LEFT (uic))) ||
2139 (IS_TRUE_SYMOP (IC_RIGHT (uic)) &&
2140 isOperandInFarSpace (IC_RIGHT (uic))))
2143 /* if the usage has only one operand then we can */
2144 if (IC_LEFT (uic) == NULL ||
2145 IC_RIGHT (uic) == NULL)
2148 /* make sure this is on the left side if not
2149 a '+' since '+' is commutative */
2150 if (ic->op != '+' &&
2151 IC_LEFT (uic)->key != IC_RESULT (ic)->key)
2154 /* if one of them is a literal then we can */
2155 if ((IC_LEFT (uic) && IS_OP_LITERAL (IC_LEFT (uic))) ||
2156 (IC_RIGHT (uic) && IS_OP_LITERAL (IC_RIGHT (uic))))
2158 OP_SYMBOL (IC_RESULT (ic))->accuse = 1;
2162 /* if the other one is not on stack then we can */
2163 if (IC_LEFT (uic)->key == IC_RESULT (ic)->key &&
2164 (IS_ITEMP (IC_RIGHT (uic)) ||
2165 (IS_TRUE_SYMOP (IC_RIGHT (uic)) &&
2166 !OP_SYMBOL (IC_RIGHT (uic))->onStack)))
2169 if (IC_RIGHT (uic)->key == IC_RESULT (ic)->key &&
2170 (IS_ITEMP (IC_LEFT (uic)) ||
2171 (IS_TRUE_SYMOP (IC_LEFT (uic)) &&
2172 !OP_SYMBOL (IC_LEFT (uic))->onStack)))
2178 OP_SYMBOL (IC_RESULT (ic))->accuse = 1;
2183 /*-----------------------------------------------------------------*/
2184 /* packForPush - hueristics to reduce iCode for pushing */
2185 /*-----------------------------------------------------------------*/
2187 packForPush (iCode * ic, eBBlock * ebp)
2192 if (ic->op != IPUSH || !IS_ITEMP (IC_LEFT (ic)))
2195 /* must have only definition & one usage */
2196 if (bitVectnBitsOn (OP_DEFS (IC_LEFT (ic))) != 1 ||
2197 bitVectnBitsOn (OP_USES (IC_LEFT (ic))) != 1)
2200 /* find the definition */
2201 if (!(dic = hTabItemWithKey (iCodehTab,
2202 bitVectFirstBit (OP_DEFS (IC_LEFT (ic))))))
2205 if (dic->op != '=' || POINTER_SET (dic))
2208 /* make sure the right side does not have any definitions
2210 dbv = OP_DEFS(IC_RIGHT(dic));
2211 for (lic = ic; lic && lic != dic ; lic = lic->prev) {
2212 if (bitVectBitValue(dbv,lic->key)) return ;
2214 /* make sure they have the same type */
2216 sym_link *itype=operandType(IC_LEFT(ic));
2217 sym_link *ditype=operandType(IC_RIGHT(dic));
2219 if (SPEC_USIGN(itype)!=SPEC_USIGN(ditype) ||
2220 SPEC_LONG(itype)!=SPEC_LONG(ditype))
2223 /* extend the live range of replaced operand if needed */
2224 if (OP_SYMBOL(IC_RIGHT(dic))->liveTo < ic->seq) {
2225 OP_SYMBOL(IC_RIGHT(dic))->liveTo = ic->seq;
2227 /* we now we know that it has one & only one def & use
2228 and the that the definition is an assignment */
2229 IC_LEFT (ic) = IC_RIGHT (dic);
2231 remiCodeFromeBBlock (ebp, dic);
2232 hTabDeleteItem (&iCodehTab, dic->key, dic, DELETE_ITEM, NULL);
2235 /*-----------------------------------------------------------------*/
2236 /* packRegisters - does some transformations to reduce register */
2238 /*-----------------------------------------------------------------*/
2240 packRegisters (eBBlock * ebp)
2250 /* look for assignments of the form */
2251 /* iTempNN = TRueSym (someoperation) SomeOperand */
2253 /* TrueSym := iTempNN:1 */
2254 for (ic = ebp->sch; ic; ic = ic->next)
2258 /* find assignment of the form TrueSym := iTempNN:1 */
2259 if (ic->op == '=' && !POINTER_SET (ic))
2260 change += packRegsForAssign (ic, ebp);
2267 for (ic = ebp->sch; ic; ic = ic->next)
2270 /* if this is an itemp & result of a address of a true sym
2271 then mark this as rematerialisable */
2272 if (ic->op == ADDRESS_OF &&
2273 IS_ITEMP (IC_RESULT (ic)) &&
2274 IS_TRUE_SYMOP (IC_LEFT (ic)) &&
2275 bitVectnBitsOn (OP_DEFS (IC_RESULT (ic))) == 1 &&
2276 !OP_SYMBOL (IC_LEFT (ic))->onStack)
2279 OP_SYMBOL (IC_RESULT (ic))->remat = 1;
2280 OP_SYMBOL (IC_RESULT (ic))->rematiCode = ic;
2281 OP_SYMBOL (IC_RESULT (ic))->usl.spillLoc = NULL;
2285 /* if straight assignment then carry remat flag if
2286 this is the only definition */
2287 if (ic->op == '=' &&
2288 !POINTER_SET (ic) &&
2289 IS_SYMOP (IC_RIGHT (ic)) &&
2290 OP_SYMBOL (IC_RIGHT (ic))->remat &&
2291 bitVectnBitsOn (OP_SYMBOL (IC_RESULT (ic))->defs) <= 1)
2294 OP_SYMBOL (IC_RESULT (ic))->remat =
2295 OP_SYMBOL (IC_RIGHT (ic))->remat;
2296 OP_SYMBOL (IC_RESULT (ic))->rematiCode =
2297 OP_SYMBOL (IC_RIGHT (ic))->rematiCode;
2300 /* if this is a +/- operation with a rematerizable
2301 then mark this as rematerializable as well */
2302 if ((ic->op == '+' || ic->op == '-') &&
2303 (IS_SYMOP (IC_LEFT (ic)) &&
2304 IS_ITEMP (IC_RESULT (ic)) &&
2305 OP_SYMBOL (IC_LEFT (ic))->remat &&
2306 bitVectnBitsOn (OP_DEFS (IC_RESULT (ic))) == 1 &&
2307 IS_OP_LITERAL (IC_RIGHT (ic))))
2310 //int i = operandLitValue(IC_RIGHT(ic));
2311 OP_SYMBOL (IC_RESULT (ic))->remat = 1;
2312 OP_SYMBOL (IC_RESULT (ic))->rematiCode = ic;
2313 OP_SYMBOL (IC_RESULT (ic))->usl.spillLoc = NULL;
2316 /* mark the pointer usages */
2317 if (POINTER_SET (ic))
2318 OP_SYMBOL (IC_RESULT (ic))->uptr = 1;
2320 if (POINTER_GET (ic))
2321 OP_SYMBOL (IC_LEFT (ic))->uptr = 1;
2325 /* if we are using a symbol on the stack
2326 then we should say ds390_ptrRegReq */
2327 if (ic->op == IFX && IS_SYMOP (IC_COND (ic)))
2328 ds390_ptrRegReq += ((OP_SYMBOL (IC_COND (ic))->onStack ||
2329 OP_SYMBOL (IC_COND (ic))->iaccess) ? 1 : 0);
2330 else if (ic->op == JUMPTABLE && IS_SYMOP (IC_JTCOND (ic)))
2331 ds390_ptrRegReq += ((OP_SYMBOL (IC_JTCOND (ic))->onStack ||
2332 OP_SYMBOL (IC_JTCOND (ic))->iaccess) ? 1 : 0);
2335 if (IS_SYMOP (IC_LEFT (ic)))
2336 ds390_ptrRegReq += ((OP_SYMBOL (IC_LEFT (ic))->onStack ||
2337 OP_SYMBOL (IC_LEFT (ic))->iaccess) ? 1 : 0);
2338 if (IS_SYMOP (IC_RIGHT (ic)))
2339 ds390_ptrRegReq += ((OP_SYMBOL (IC_RIGHT (ic))->onStack ||
2340 OP_SYMBOL (IC_RIGHT (ic))->iaccess) ? 1 : 0);
2341 if (IS_SYMOP (IC_RESULT (ic)))
2342 ds390_ptrRegReq += ((OP_SYMBOL (IC_RESULT (ic))->onStack ||
2343 OP_SYMBOL (IC_RESULT (ic))->iaccess) ? 1 : 0);
2348 /* if the condition of an if instruction
2349 is defined in the previous instruction then
2350 mark the itemp as a conditional */
2351 if ((IS_CONDITIONAL (ic) ||
2352 (IS_BITWISE_OP(ic) && isBitwiseOptimizable(ic))) &&
2353 ic->next && ic->next->op == IFX &&
2354 isOperandEqual (IC_RESULT (ic), IC_COND (ic->next)) &&
2355 OP_SYMBOL (IC_RESULT (ic))->liveTo <= ic->next->seq)
2358 OP_SYMBOL (IC_RESULT (ic))->regType = REG_CND;
2362 /* if the condition of an if instruction
2363 is defined in the previous instruction and
2364 this is the only usage then
2365 mark the itemp as a conditional */
2366 if ((IS_CONDITIONAL (ic) ||
2367 (IS_BITWISE_OP(ic) && isBitwiseOptimizable (ic))) &&
2368 ic->next && ic->next->op == IFX &&
2369 bitVectnBitsOn (OP_USES(IC_RESULT(ic)))==1 &&
2370 isOperandEqual (IC_RESULT (ic), IC_COND (ic->next)) &&
2371 OP_SYMBOL (IC_RESULT (ic))->liveTo <= ic->next->seq)
2373 OP_SYMBOL (IC_RESULT (ic))->regType = REG_CND;
2378 /* reduce for support function calls */
2379 if (ic->supportRtn || ic->op == '+' || ic->op == '-')
2380 packRegsForSupport (ic, ebp);
2382 /* some cases the redundant moves can
2383 can be eliminated for return statements */
2384 if ((ic->op == RETURN || ic->op == SEND) &&
2385 !isOperandInFarSpace (IC_LEFT (ic)) &&
2387 packRegsForOneuse (ic, IC_LEFT (ic), ebp);
2389 /* if pointer set & left has a size more than
2390 one and right is not in far space */
2391 if (POINTER_SET (ic) &&
2392 !isOperandInFarSpace (IC_RIGHT (ic)) &&
2393 !OP_SYMBOL (IC_RESULT (ic))->remat &&
2394 !IS_OP_RUONLY (IC_RIGHT (ic)) &&
2395 getSize (aggrToPtr (operandType (IC_RESULT (ic)), FALSE)) > 1)
2397 packRegsForOneuse (ic, IC_RESULT (ic), ebp);
2399 /* if pointer get */
2400 if (POINTER_GET (ic) &&
2401 !isOperandInFarSpace (IC_RESULT (ic)) &&
2402 !OP_SYMBOL (IC_LEFT (ic))->remat &&
2403 !IS_OP_RUONLY (IC_RESULT (ic)) &&
2404 getSize (aggrToPtr (operandType (IC_LEFT (ic)), FALSE)) > 1)
2406 packRegsForOneuse (ic, IC_LEFT (ic), ebp);
2409 /* if this is cast for intergral promotion then
2410 check if only use of the definition of the
2411 operand being casted/ if yes then replace
2412 the result of that arithmetic operation with
2413 this result and get rid of the cast */
2416 sym_link *fromType = operandType (IC_RIGHT (ic));
2417 sym_link *toType = operandType (IC_LEFT (ic));
2419 if (IS_INTEGRAL (fromType) && IS_INTEGRAL (toType) &&
2420 getSize (fromType) != getSize (toType) &&
2421 SPEC_USIGN (fromType) == SPEC_USIGN (toType))
2424 iCode *dic = packRegsForOneuse (ic, IC_RIGHT (ic), ebp);
2427 if (IS_ARITHMETIC_OP (dic))
2429 IC_RESULT (dic) = IC_RESULT (ic);
2430 remiCodeFromeBBlock (ebp, ic);
2431 hTabDeleteItem (&iCodehTab, ic->key, ic, DELETE_ITEM, NULL);
2432 OP_DEFS (IC_RESULT (dic)) = bitVectSetBit (OP_DEFS (IC_RESULT (dic)), dic->key);
2436 OP_SYMBOL (IC_RIGHT (ic))->ruonly = 0;
2442 /* if the type from and type to are the same
2443 then if this is the only use then packit */
2444 if (compareType (operandType (IC_RIGHT (ic)),
2445 operandType (IC_LEFT (ic))) == 1)
2447 iCode *dic = packRegsForOneuse (ic, IC_RIGHT (ic), ebp);
2450 IC_RESULT (dic) = IC_RESULT (ic);
2451 remiCodeFromeBBlock (ebp, ic);
2452 hTabDeleteItem (&iCodehTab, ic->key, ic, DELETE_ITEM, NULL);
2453 OP_DEFS (IC_RESULT (dic)) = bitVectSetBit (OP_DEFS (IC_RESULT (dic)), dic->key);
2461 iTempNN := (some variable in farspace) V1
2466 if (ic->op == IPUSH)
2468 packForPush (ic, ebp);
2472 /* pack registers for accumulator use, when the
2473 result of an arithmetic or bit wise operation
2474 has only one use, that use is immediately following
2475 the defintion and the using iCode has only one
2476 operand or has two operands but one is literal &
2477 the result of that operation is not on stack then
2478 we can leave the result of this operation in acc:b
2480 if ((IS_ARITHMETIC_OP (ic)
2482 || IS_BITWISE_OP (ic)
2484 || ic->op == LEFT_OP || ic->op == RIGHT_OP
2487 IS_ITEMP (IC_RESULT (ic)) &&
2488 getSize (operandType (IC_RESULT (ic))) <= 2)
2490 packRegsForAccUse (ic);
2495 /*-----------------------------------------------------------------*/
2496 /* assignRegisters - assigns registers to each live range as need */
2497 /*-----------------------------------------------------------------*/
2499 ds390_assignRegisters (eBBlock ** ebbs, int count)
2504 setToNull ((void *) &_G.funcrUsed);
2505 ds390_ptrRegReq = _G.stackExtend = _G.dataExtend = 0;
2508 /* change assignments this will remove some
2509 live ranges reducing some register pressure */
2510 for (i = 0; i < count; i++)
2511 packRegisters (ebbs[i]);
2513 if (options.dump_pack)
2514 dumpEbbsToFileExt (DUMP_PACK, ebbs, count);
2516 /* first determine for each live range the number of
2517 registers & the type of registers required for each */
2520 /* and serially allocate registers */
2521 serialRegAssign (ebbs, count);
2523 /* if stack was extended then tell the user */
2526 /* werror(W_TOOMANY_SPILS,"stack", */
2527 /* _G.stackExtend,currFunc->name,""); */
2533 /* werror(W_TOOMANY_SPILS,"data space", */
2534 /* _G.dataExtend,currFunc->name,""); */
2538 /* after that create the register mask
2539 for each of the instruction */
2540 createRegMask (ebbs, count);
2542 /* redo that offsets for stacked automatic variables */
2543 redoStackOffsets ();
2545 if (options.dump_rassgn)
2546 dumpEbbsToFileExt (DUMP_RASSGN, ebbs, count);
2548 /* do the overlaysegment stuff SDCCmem.c */
2549 doOverlays (ebbs, count);
2551 /* now get back the chain */
2552 ic = iCodeLabelOptimize (iCodeFromeBBlock (ebbs, count));
2557 /* free up any _G.stackSpil locations allocated */
2558 applyToSet (_G.stackSpil, deallocStackSpil);
2560 setToNull ((void **) &_G.stackSpil);
2561 setToNull ((void **) &_G.spiltSet);
2562 /* mark all registers as free */