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))) &&
1441 !IS_BITVAR (sym->etype))
1445 /* if remat in data space */
1446 if (OP_SYMBOL (IC_LEFT (ic))->remat &&
1448 DCL_TYPE (aggrToPtr (sym->type, FALSE)) == POINTER)
1451 /* create a psuedo symbol & force a spil */
1452 symbol *psym = newSymbol (rematStr (OP_SYMBOL (IC_LEFT (ic))), 1);
1453 psym->type = sym->type;
1454 psym->etype = sym->etype;
1455 strcpy (psym->rname, psym->name);
1457 sym->usl.spillLoc = psym;
1461 /* if in data space or idata space then try to
1462 allocate pointer register */
1466 /* if not then we require registers */
1467 sym->nRegs = ((IS_AGGREGATE (sym->type) || sym->isptr) ?
1468 getSize (sym->type = aggrToPtr (sym->type, FALSE)) :
1469 getSize (sym->type));
1473 fprintf (stderr, "allocated more than 4 or 0 registers for type ");
1474 printTypeChain (sym->type, stderr);
1475 fprintf (stderr, "\n");
1478 /* determine the type of register required */
1479 if (sym->nRegs == 1 &&
1480 IS_PTR (sym->type) &&
1482 sym->regType = REG_PTR;
1484 sym->regType = REG_GPR;
1488 /* for the first run we don't provide */
1489 /* registers for true symbols we will */
1490 /* see how things go */
1496 /*-----------------------------------------------------------------*/
1497 /* freeAllRegs - mark all registers as free */
1498 /*-----------------------------------------------------------------*/
1504 for (i = 0; i < ds390_nRegs; i++)
1505 regs390[i].isFree = 1;
1508 /*-----------------------------------------------------------------*/
1509 /* deallocStackSpil - this will set the stack pointer back */
1510 /*-----------------------------------------------------------------*/
1512 DEFSETFUNC (deallocStackSpil)
1520 /*-----------------------------------------------------------------*/
1521 /* farSpacePackable - returns the packable icode for far variables */
1522 /*-----------------------------------------------------------------*/
1524 farSpacePackable (iCode * ic)
1528 /* go thru till we find a definition for the
1529 symbol on the right */
1530 for (dic = ic->prev; dic; dic = dic->prev)
1533 /* if the definition is a call then no */
1534 if ((dic->op == CALL || dic->op == PCALL) &&
1535 IC_RESULT (dic)->key == IC_RIGHT (ic)->key)
1540 /* if shift by unknown amount then not */
1541 if ((dic->op == LEFT_OP || dic->op == RIGHT_OP) &&
1542 IC_RESULT (dic)->key == IC_RIGHT (ic)->key)
1545 /* if pointer get and size > 1 */
1546 if (POINTER_GET (dic) &&
1547 getSize (aggrToPtr (operandType (IC_LEFT (dic)), FALSE)) > 1)
1550 if (POINTER_SET (dic) &&
1551 getSize (aggrToPtr (operandType (IC_RESULT (dic)), FALSE)) > 1)
1554 /* if any three is a true symbol in far space */
1555 if (IC_RESULT (dic) &&
1556 IS_TRUE_SYMOP (IC_RESULT (dic)) &&
1557 isOperandInFarSpace (IC_RESULT (dic)))
1560 if (IC_RIGHT (dic) &&
1561 IS_TRUE_SYMOP (IC_RIGHT (dic)) &&
1562 isOperandInFarSpace (IC_RIGHT (dic)) &&
1563 !isOperandEqual (IC_RIGHT (dic), IC_RESULT (ic)))
1566 if (IC_LEFT (dic) &&
1567 IS_TRUE_SYMOP (IC_LEFT (dic)) &&
1568 isOperandInFarSpace (IC_LEFT (dic)) &&
1569 !isOperandEqual (IC_LEFT (dic), IC_RESULT (ic)))
1572 if (isOperandEqual (IC_RIGHT (ic), IC_RESULT (dic)))
1574 if ((dic->op == LEFT_OP ||
1575 dic->op == RIGHT_OP ||
1577 IS_OP_LITERAL (IC_RIGHT (dic)))
1587 /*-----------------------------------------------------------------*/
1588 /* packRegsForAssign - register reduction for assignment */
1589 /*-----------------------------------------------------------------*/
1591 packRegsForAssign (iCode * ic, eBBlock * ebp)
1595 if (!IS_ITEMP (IC_RIGHT (ic)) ||
1596 OP_SYMBOL (IC_RIGHT (ic))->isind ||
1597 OP_LIVETO (IC_RIGHT (ic)) > ic->seq)
1602 /* if the true symbol is defined in far space or on stack
1603 then we should not since this will increase register pressure */
1605 if (isOperandInFarSpace (IC_RESULT (ic)))
1607 if ((dic = farSpacePackable (ic)))
1613 if (isOperandInFarSpace(IC_RESULT(ic)) && !farSpacePackable(ic)) {
1618 /* find the definition of iTempNN scanning backwards if we find a
1619 a use of the true symbol in before we find the definition then
1621 for (dic = ic->prev; dic; dic = dic->prev)
1623 /* if there is a function call then don't pack it */
1624 if ((dic->op == CALL || dic->op == PCALL))
1633 if (IS_TRUE_SYMOP (IC_RESULT (dic)) &&
1634 IS_OP_VOLATILE (IC_RESULT (dic)))
1640 if (IS_SYMOP (IC_RESULT (dic)) &&
1641 IC_RESULT (dic)->key == IC_RIGHT (ic)->key)
1643 if (POINTER_SET (dic))
1649 if (IS_SYMOP (IC_RIGHT (dic)) &&
1650 (IC_RIGHT (dic)->key == IC_RESULT (ic)->key ||
1651 IC_RIGHT (dic)->key == IC_RIGHT (ic)->key))
1657 if (IS_SYMOP (IC_LEFT (dic)) &&
1658 (IC_LEFT (dic)->key == IC_RESULT (ic)->key ||
1659 IC_LEFT (dic)->key == IC_RIGHT (ic)->key))
1665 if (POINTER_SET (dic) &&
1666 IC_RESULT (dic)->key == IC_RESULT (ic)->key)
1674 return 0; /* did not find */
1676 /* if the result is on stack or iaccess then it must be
1677 the same atleast one of the operands */
1678 if (OP_SYMBOL (IC_RESULT (ic))->onStack ||
1679 OP_SYMBOL (IC_RESULT (ic))->iaccess)
1682 /* the operation has only one symbol
1683 operator then we can pack */
1684 if ((IC_LEFT (dic) && !IS_SYMOP (IC_LEFT (dic))) ||
1685 (IC_RIGHT (dic) && !IS_SYMOP (IC_RIGHT (dic))))
1688 if (!((IC_LEFT (dic) &&
1689 IC_RESULT (ic)->key == IC_LEFT (dic)->key) ||
1691 IC_RESULT (ic)->key == IC_RIGHT (dic)->key)))
1695 /* found the definition */
1696 /* replace the result with the result of */
1697 /* this assignment and remove this assignment */
1698 IC_RESULT (dic) = IC_RESULT (ic);
1700 if (IS_ITEMP (IC_RESULT (dic)) && OP_SYMBOL (IC_RESULT (dic))->liveFrom > dic->seq)
1702 OP_SYMBOL (IC_RESULT (dic))->liveFrom = dic->seq;
1704 /* delete from liverange table also
1705 delete from all the points inbetween and the new
1707 for (sic = dic; sic != ic; sic = sic->next)
1709 bitVectUnSetBit (sic->rlive, IC_RESULT (ic)->key);
1710 if (IS_ITEMP (IC_RESULT (dic)))
1711 bitVectSetBit (sic->rlive, IC_RESULT (dic)->key);
1714 remiCodeFromeBBlock (ebp, ic);
1715 hTabDeleteItem (&iCodehTab, ic->key, ic, DELETE_ITEM, NULL);
1716 OP_DEFS (IC_RESULT (dic)) = bitVectSetBit (OP_DEFS (IC_RESULT (dic)), dic->key);
1721 /*-----------------------------------------------------------------*/
1722 /* findAssignToSym : scanning backwards looks for first assig found */
1723 /*-----------------------------------------------------------------*/
1725 findAssignToSym (operand * op, iCode * ic)
1729 for (dic = ic->prev; dic; dic = dic->prev)
1732 /* if definition by assignment */
1733 if (dic->op == '=' &&
1734 !POINTER_SET (dic) &&
1735 IC_RESULT (dic)->key == op->key
1736 /* && IS_TRUE_SYMOP(IC_RIGHT(dic)) */
1740 /* we are interested only if defined in far space */
1741 /* or in stack space in case of + & - */
1743 /* if assigned to a non-symbol then return
1745 if (!IS_SYMOP (IC_RIGHT (dic)))
1748 /* if the symbol is in far space then
1750 if (isOperandInFarSpace (IC_RIGHT (dic)))
1753 /* for + & - operations make sure that
1754 if it is on the stack it is the same
1755 as one of the three operands */
1756 if ((ic->op == '+' || ic->op == '-') &&
1757 OP_SYMBOL (IC_RIGHT (dic))->onStack)
1760 if (IC_RESULT (ic)->key != IC_RIGHT (dic)->key &&
1761 IC_LEFT (ic)->key != IC_RIGHT (dic)->key &&
1762 IC_RIGHT (ic)->key != IC_RIGHT (dic)->key)
1770 /* if we find an usage then we cannot delete it */
1771 if (IC_LEFT (dic) && IC_LEFT (dic)->key == op->key)
1774 if (IC_RIGHT (dic) && IC_RIGHT (dic)->key == op->key)
1777 if (POINTER_SET (dic) && IC_RESULT (dic)->key == op->key)
1781 /* now make sure that the right side of dic
1782 is not defined between ic & dic */
1785 iCode *sic = dic->next;
1787 for (; sic != ic; sic = sic->next)
1788 if (IC_RESULT (sic) &&
1789 IC_RESULT (sic)->key == IC_RIGHT (dic)->key)
1798 /*-----------------------------------------------------------------*/
1799 /* packRegsForSupport :- reduce some registers for support calls */
1800 /*-----------------------------------------------------------------*/
1802 packRegsForSupport (iCode * ic, eBBlock * ebp)
1805 /* for the left & right operand :- look to see if the
1806 left was assigned a true symbol in far space in that
1807 case replace them */
1808 if (IS_ITEMP (IC_LEFT (ic)) &&
1809 OP_SYMBOL (IC_LEFT (ic))->liveTo <= ic->seq)
1811 iCode *dic = findAssignToSym (IC_LEFT (ic), ic);
1817 /* found it we need to remove it from the
1819 for (sic = dic; sic != ic; sic = sic->next)
1820 bitVectUnSetBit (sic->rlive, IC_LEFT (ic)->key);
1822 IC_LEFT (ic)->operand.symOperand =
1823 IC_RIGHT (dic)->operand.symOperand;
1824 IC_LEFT (ic)->key = IC_RIGHT (dic)->operand.symOperand->key;
1825 remiCodeFromeBBlock (ebp, dic);
1826 hTabDeleteItem (&iCodehTab, dic->key, dic, DELETE_ITEM, NULL);
1830 /* do the same for the right operand */
1833 IS_ITEMP (IC_RIGHT (ic)) &&
1834 OP_SYMBOL (IC_RIGHT (ic))->liveTo <= ic->seq)
1836 iCode *dic = findAssignToSym (IC_RIGHT (ic), ic);
1842 /* if this is a subtraction & the result
1843 is a true symbol in far space then don't pack */
1844 if (ic->op == '-' && IS_TRUE_SYMOP (IC_RESULT (dic)))
1846 sym_link *etype = getSpec (operandType (IC_RESULT (dic)));
1847 if (IN_FARSPACE (SPEC_OCLS (etype)))
1850 /* found it we need to remove it from the
1852 for (sic = dic; sic != ic; sic = sic->next)
1853 bitVectUnSetBit (sic->rlive, IC_RIGHT (ic)->key);
1855 IC_RIGHT (ic)->operand.symOperand =
1856 IC_RIGHT (dic)->operand.symOperand;
1857 IC_RIGHT (ic)->key = IC_RIGHT (dic)->operand.symOperand->key;
1859 remiCodeFromeBBlock (ebp, dic);
1860 hTabDeleteItem (&iCodehTab, dic->key, dic, DELETE_ITEM, NULL);
1867 #define IS_OP_RUONLY(x) (x && IS_SYMOP(x) && OP_SYMBOL(x)->ruonly)
1870 /*-----------------------------------------------------------------*/
1871 /* packRegsForOneuse : - will reduce some registers for single Use */
1872 /*-----------------------------------------------------------------*/
1874 packRegsForOneuse (iCode * ic, operand * op, eBBlock * ebp)
1878 /* I can't figure out how to make this safe yet. */
1879 if ((int)ic+(int)op+(int)ebp) {
1890 /* if returning a literal then do nothing */
1894 /* only upto 2 bytes since we cannot predict
1895 the usage of b, & acc */
1896 if (getSize (operandType (op)) > (fReturnSizeDS390 - 2) &&
1899 !POINTER_SET (ic) &&
1903 /* this routine will mark the a symbol as used in one
1904 instruction use only && if the defintion is local
1905 (ie. within the basic block) && has only one definition &&
1906 that definiion is either a return value from a
1907 function or does not contain any variables in
1909 uses = bitVectCopy (OP_USES (op));
1910 bitVectUnSetBit (uses, ic->key); /* take away this iCode */
1911 if (!bitVectIsZero (uses)) /* has other uses */
1914 /* if it has only one defintion */
1915 if (bitVectnBitsOn (OP_DEFS (op)) > 1)
1916 return NULL; /* has more than one definition */
1918 /* get the that definition */
1920 hTabItemWithKey (iCodehTab,
1921 bitVectFirstBit (OP_DEFS (op)))))
1924 /* if that only usage is a cast */
1925 if (dic->op == CAST) {
1926 /* to a bigger type */
1927 if (getSize(OP_SYM_TYPE(IC_RESULT(dic))) >
1928 getSize(OP_SYM_TYPE(IC_RIGHT(dic)))) {
1929 /* than we can not, since we cannot predict the usage of b & acc */
1934 /* found the definition now check if it is local */
1935 if (dic->seq < ebp->fSeq ||
1936 dic->seq > ebp->lSeq)
1937 return NULL; /* non-local */
1939 /* now check if it is the return from
1941 if (dic->op == CALL || dic->op == PCALL)
1943 if (ic->op != SEND && ic->op != RETURN)
1945 OP_SYMBOL (op)->ruonly = 1;
1952 /* otherwise check that the definition does
1953 not contain any symbols in far space */
1954 if (isOperandInFarSpace (IC_LEFT (dic)) ||
1955 isOperandInFarSpace (IC_RIGHT (dic)) ||
1956 IS_OP_RUONLY (IC_LEFT (ic)) ||
1957 IS_OP_RUONLY (IC_RIGHT (ic)))
1962 /* if pointer set then make sure the pointer
1964 if (POINTER_SET (dic) &&
1965 !IS_DATA_PTR (aggrToPtr (operandType (IC_RESULT (dic)), FALSE)))
1968 if (POINTER_GET (dic) &&
1969 !IS_DATA_PTR (aggrToPtr (operandType (IC_LEFT (dic)), FALSE)))
1974 /* also make sure the intervenening instructions
1975 don't have any thing in far space */
1976 for (dic = dic->next; dic && dic != ic; dic = dic->next)
1979 /* if there is an intervening function call then no */
1980 if (dic->op == CALL || dic->op == PCALL)
1982 /* if pointer set then make sure the pointer
1984 if (POINTER_SET (dic) &&
1985 !IS_DATA_PTR (aggrToPtr (operandType (IC_RESULT (dic)), FALSE)))
1988 if (POINTER_GET (dic) &&
1989 !IS_DATA_PTR (aggrToPtr (operandType (IC_LEFT (dic)), FALSE)))
1992 /* if address of & the result is remat the okay */
1993 if (dic->op == ADDRESS_OF &&
1994 OP_SYMBOL (IC_RESULT (dic))->remat)
1997 /* if operand has size of three or more & this
1998 operation is a '*','/' or '%' then 'b' may
2000 if ((dic->op == '%' || dic->op == '/' || dic->op == '*') &&
2001 getSize (operandType (op)) >= 3)
2004 /* if left or right or result is in far space */
2005 if (isOperandInFarSpace (IC_LEFT (dic)) ||
2006 isOperandInFarSpace (IC_RIGHT (dic)) ||
2007 isOperandInFarSpace (IC_RESULT (dic)) ||
2008 IS_OP_RUONLY (IC_LEFT (dic)) ||
2009 IS_OP_RUONLY (IC_RIGHT (dic)) ||
2010 IS_OP_RUONLY (IC_RESULT (dic)))
2016 OP_SYMBOL (op)->ruonly = 1;
2021 /*-----------------------------------------------------------------*/
2022 /* isBitwiseOptimizable - requirements of JEAN LOUIS VERN */
2023 /*-----------------------------------------------------------------*/
2025 isBitwiseOptimizable (iCode * ic)
2027 sym_link *ltype = getSpec (operandType (IC_LEFT (ic)));
2028 sym_link *rtype = getSpec (operandType (IC_RIGHT (ic)));
2030 /* bitwise operations are considered optimizable
2031 under the following conditions (Jean-Louis VERN)
2043 if ( IS_LITERAL (rtype) ||
2044 (IS_BITVAR (ltype) && IN_BITSPACE (SPEC_OCLS (ltype))))
2050 /*-----------------------------------------------------------------*/
2051 /* packRegsForAccUse - pack registers for acc use */
2052 /*-----------------------------------------------------------------*/
2054 packRegsForAccUse (iCode * ic)
2058 /* if + or - then it has to be one byte result */
2059 if ((ic->op == '+' || ic->op == '-')
2060 && getSize (operandType (IC_RESULT (ic))) > 1)
2063 /* if shift operation make sure right side is not a literal */
2064 if (ic->op == RIGHT_OP &&
2065 (isOperandLiteral (IC_RIGHT (ic)) ||
2066 getSize (operandType (IC_RESULT (ic))) > 1))
2069 if (ic->op == LEFT_OP &&
2070 (isOperandLiteral (IC_RIGHT (ic)) ||
2071 getSize (operandType (IC_RESULT (ic))) > 1))
2074 if (IS_BITWISE_OP (ic) &&
2075 getSize (operandType (IC_RESULT (ic))) > 1)
2079 /* has only one definition */
2080 if (bitVectnBitsOn (OP_DEFS (IC_RESULT (ic))) > 1)
2083 /* has only one use */
2084 if (bitVectnBitsOn (OP_USES (IC_RESULT (ic))) > 1)
2087 /* and the usage immediately follows this iCode */
2088 if (!(uic = hTabItemWithKey (iCodehTab,
2089 bitVectFirstBit (OP_USES (IC_RESULT (ic))))))
2092 if (ic->next != uic)
2095 /* if it is a conditional branch then we definitely can */
2099 if (uic->op == JUMPTABLE)
2102 /* if the usage is not is an assignment
2103 or an arithmetic / bitwise / shift operation then not */
2104 if (POINTER_SET (uic) &&
2105 getSize (aggrToPtr (operandType (IC_RESULT (uic)), FALSE)) > 1)
2108 if (uic->op != '=' &&
2109 !IS_ARITHMETIC_OP (uic) &&
2110 !IS_BITWISE_OP (uic) &&
2111 uic->op != LEFT_OP &&
2112 uic->op != RIGHT_OP)
2115 /* if used in ^ operation then make sure right is not a
2117 if (uic->op == '^' && isOperandLiteral (IC_RIGHT (uic)))
2120 /* if shift operation make sure right side is not a literal */
2121 if (uic->op == RIGHT_OP &&
2122 (isOperandLiteral (IC_RIGHT (uic)) ||
2123 getSize (operandType (IC_RESULT (uic))) > 1))
2126 if (uic->op == LEFT_OP &&
2127 (isOperandLiteral (IC_RIGHT (uic)) ||
2128 getSize (operandType (IC_RESULT (uic))) > 1))
2131 /* make sure that the result of this icode is not on the
2132 stack, since acc is used to compute stack offset */
2133 if (IS_TRUE_SYMOP (IC_RESULT (uic)) &&
2134 OP_SYMBOL (IC_RESULT (uic))->onStack)
2137 /* if either one of them in far space then we cannot */
2138 if ((IS_TRUE_SYMOP (IC_LEFT (uic)) &&
2139 isOperandInFarSpace (IC_LEFT (uic))) ||
2140 (IS_TRUE_SYMOP (IC_RIGHT (uic)) &&
2141 isOperandInFarSpace (IC_RIGHT (uic))))
2144 /* if the usage has only one operand then we can */
2145 if (IC_LEFT (uic) == NULL ||
2146 IC_RIGHT (uic) == NULL)
2149 /* make sure this is on the left side if not
2150 a '+' since '+' is commutative */
2151 if (ic->op != '+' &&
2152 IC_LEFT (uic)->key != IC_RESULT (ic)->key)
2156 // this is too dangerous and need further restrictions
2159 /* if one of them is a literal then we can */
2160 if ((IC_LEFT (uic) && IS_OP_LITERAL (IC_LEFT (uic))) ||
2161 (IC_RIGHT (uic) && IS_OP_LITERAL (IC_RIGHT (uic))))
2163 OP_SYMBOL (IC_RESULT (ic))->accuse = 1;
2168 /* if the other one is not on stack then we can */
2169 if (IC_LEFT (uic)->key == IC_RESULT (ic)->key &&
2170 (IS_ITEMP (IC_RIGHT (uic)) ||
2171 (IS_TRUE_SYMOP (IC_RIGHT (uic)) &&
2172 !OP_SYMBOL (IC_RIGHT (uic))->onStack)))
2175 if (IC_RIGHT (uic)->key == IC_RESULT (ic)->key &&
2176 (IS_ITEMP (IC_LEFT (uic)) ||
2177 (IS_TRUE_SYMOP (IC_LEFT (uic)) &&
2178 !OP_SYMBOL (IC_LEFT (uic))->onStack)))
2184 OP_SYMBOL (IC_RESULT (ic))->accuse = 1;
2189 /*-----------------------------------------------------------------*/
2190 /* packForPush - hueristics to reduce iCode for pushing */
2191 /*-----------------------------------------------------------------*/
2193 packForPush (iCode * ic, eBBlock * ebp)
2198 if (ic->op != IPUSH || !IS_ITEMP (IC_LEFT (ic)))
2201 /* must have only definition & one usage */
2202 if (bitVectnBitsOn (OP_DEFS (IC_LEFT (ic))) != 1 ||
2203 bitVectnBitsOn (OP_USES (IC_LEFT (ic))) != 1)
2206 /* find the definition */
2207 if (!(dic = hTabItemWithKey (iCodehTab,
2208 bitVectFirstBit (OP_DEFS (IC_LEFT (ic))))))
2211 if (dic->op != '=' || POINTER_SET (dic))
2214 /* make sure the right side does not have any definitions
2216 dbv = OP_DEFS(IC_RIGHT(dic));
2217 for (lic = ic; lic && lic != dic ; lic = lic->prev) {
2218 if (bitVectBitValue(dbv,lic->key)) return ;
2220 /* make sure they have the same type */
2222 sym_link *itype=operandType(IC_LEFT(ic));
2223 sym_link *ditype=operandType(IC_RIGHT(dic));
2225 if (SPEC_USIGN(itype)!=SPEC_USIGN(ditype) ||
2226 SPEC_LONG(itype)!=SPEC_LONG(ditype))
2229 /* extend the live range of replaced operand if needed */
2230 if (OP_SYMBOL(IC_RIGHT(dic))->liveTo < ic->seq) {
2231 OP_SYMBOL(IC_RIGHT(dic))->liveTo = ic->seq;
2233 /* we now we know that it has one & only one def & use
2234 and the that the definition is an assignment */
2235 IC_LEFT (ic) = IC_RIGHT (dic);
2237 remiCodeFromeBBlock (ebp, dic);
2238 hTabDeleteItem (&iCodehTab, dic->key, dic, DELETE_ITEM, NULL);
2241 /*-----------------------------------------------------------------*/
2242 /* packRegisters - does some transformations to reduce register */
2244 /*-----------------------------------------------------------------*/
2246 packRegisters (eBBlock * ebp)
2256 /* look for assignments of the form */
2257 /* iTempNN = TRueSym (someoperation) SomeOperand */
2259 /* TrueSym := iTempNN:1 */
2260 for (ic = ebp->sch; ic; ic = ic->next)
2264 /* find assignment of the form TrueSym := iTempNN:1 */
2265 if (ic->op == '=' && !POINTER_SET (ic))
2266 change += packRegsForAssign (ic, ebp);
2273 for (ic = ebp->sch; ic; ic = ic->next)
2276 /* if this is an itemp & result of a address of a true sym
2277 then mark this as rematerialisable */
2278 if (ic->op == ADDRESS_OF &&
2279 IS_ITEMP (IC_RESULT (ic)) &&
2280 IS_TRUE_SYMOP (IC_LEFT (ic)) &&
2281 bitVectnBitsOn (OP_DEFS (IC_RESULT (ic))) == 1 &&
2282 !OP_SYMBOL (IC_LEFT (ic))->onStack)
2285 OP_SYMBOL (IC_RESULT (ic))->remat = 1;
2286 OP_SYMBOL (IC_RESULT (ic))->rematiCode = ic;
2287 OP_SYMBOL (IC_RESULT (ic))->usl.spillLoc = NULL;
2291 /* if straight assignment then carry remat flag if
2292 this is the only definition */
2293 if (ic->op == '=' &&
2294 !POINTER_SET (ic) &&
2295 IS_SYMOP (IC_RIGHT (ic)) &&
2296 OP_SYMBOL (IC_RIGHT (ic))->remat &&
2297 bitVectnBitsOn (OP_SYMBOL (IC_RESULT (ic))->defs) <= 1)
2300 OP_SYMBOL (IC_RESULT (ic))->remat =
2301 OP_SYMBOL (IC_RIGHT (ic))->remat;
2302 OP_SYMBOL (IC_RESULT (ic))->rematiCode =
2303 OP_SYMBOL (IC_RIGHT (ic))->rematiCode;
2306 /* if this is a +/- operation with a rematerizable
2307 then mark this as rematerializable as well */
2308 if ((ic->op == '+' || ic->op == '-') &&
2309 (IS_SYMOP (IC_LEFT (ic)) &&
2310 IS_ITEMP (IC_RESULT (ic)) &&
2311 OP_SYMBOL (IC_LEFT (ic))->remat &&
2312 bitVectnBitsOn (OP_DEFS (IC_RESULT (ic))) == 1 &&
2313 IS_OP_LITERAL (IC_RIGHT (ic))))
2316 //int i = operandLitValue(IC_RIGHT(ic));
2317 OP_SYMBOL (IC_RESULT (ic))->remat = 1;
2318 OP_SYMBOL (IC_RESULT (ic))->rematiCode = ic;
2319 OP_SYMBOL (IC_RESULT (ic))->usl.spillLoc = NULL;
2322 /* mark the pointer usages */
2323 if (POINTER_SET (ic))
2324 OP_SYMBOL (IC_RESULT (ic))->uptr = 1;
2326 if (POINTER_GET (ic))
2327 OP_SYMBOL (IC_LEFT (ic))->uptr = 1;
2331 /* if we are using a symbol on the stack
2332 then we should say ds390_ptrRegReq */
2333 if (ic->op == IFX && IS_SYMOP (IC_COND (ic)))
2334 ds390_ptrRegReq += ((OP_SYMBOL (IC_COND (ic))->onStack ||
2335 OP_SYMBOL (IC_COND (ic))->iaccess) ? 1 : 0);
2336 else if (ic->op == JUMPTABLE && IS_SYMOP (IC_JTCOND (ic)))
2337 ds390_ptrRegReq += ((OP_SYMBOL (IC_JTCOND (ic))->onStack ||
2338 OP_SYMBOL (IC_JTCOND (ic))->iaccess) ? 1 : 0);
2341 if (IS_SYMOP (IC_LEFT (ic)))
2342 ds390_ptrRegReq += ((OP_SYMBOL (IC_LEFT (ic))->onStack ||
2343 OP_SYMBOL (IC_LEFT (ic))->iaccess) ? 1 : 0);
2344 if (IS_SYMOP (IC_RIGHT (ic)))
2345 ds390_ptrRegReq += ((OP_SYMBOL (IC_RIGHT (ic))->onStack ||
2346 OP_SYMBOL (IC_RIGHT (ic))->iaccess) ? 1 : 0);
2347 if (IS_SYMOP (IC_RESULT (ic)))
2348 ds390_ptrRegReq += ((OP_SYMBOL (IC_RESULT (ic))->onStack ||
2349 OP_SYMBOL (IC_RESULT (ic))->iaccess) ? 1 : 0);
2354 /* if the condition of an if instruction
2355 is defined in the previous instruction then
2356 mark the itemp as a conditional */
2357 if ((IS_CONDITIONAL (ic) ||
2358 (IS_BITWISE_OP(ic) && isBitwiseOptimizable(ic))) &&
2359 ic->next && ic->next->op == IFX &&
2360 isOperandEqual (IC_RESULT (ic), IC_COND (ic->next)) &&
2361 OP_SYMBOL (IC_RESULT (ic))->liveTo <= ic->next->seq)
2364 OP_SYMBOL (IC_RESULT (ic))->regType = REG_CND;
2368 /* if the condition of an if instruction
2369 is defined in the previous instruction and
2370 this is the only usage then
2371 mark the itemp as a conditional */
2372 if ((IS_CONDITIONAL (ic) ||
2373 (IS_BITWISE_OP(ic) && isBitwiseOptimizable (ic))) &&
2374 ic->next && ic->next->op == IFX &&
2375 bitVectnBitsOn (OP_USES(IC_RESULT(ic)))==1 &&
2376 isOperandEqual (IC_RESULT (ic), IC_COND (ic->next)) &&
2377 OP_SYMBOL (IC_RESULT (ic))->liveTo <= ic->next->seq)
2379 OP_SYMBOL (IC_RESULT (ic))->regType = REG_CND;
2384 /* reduce for support function calls */
2385 if (ic->supportRtn || ic->op == '+' || ic->op == '-')
2386 packRegsForSupport (ic, ebp);
2388 /* some cases the redundant moves can
2389 can be eliminated for return statements */
2390 if ((ic->op == RETURN || ic->op == SEND) &&
2391 !isOperandInFarSpace (IC_LEFT (ic)) &&
2393 packRegsForOneuse (ic, IC_LEFT (ic), ebp);
2395 /* if pointer set & left has a size more than
2396 one and right is not in far space */
2397 if (POINTER_SET (ic) &&
2398 !isOperandInFarSpace (IC_RIGHT (ic)) &&
2399 !OP_SYMBOL (IC_RESULT (ic))->remat &&
2400 !IS_OP_RUONLY (IC_RIGHT (ic)) &&
2401 getSize (aggrToPtr (operandType (IC_RESULT (ic)), FALSE)) > 1)
2403 packRegsForOneuse (ic, IC_RESULT (ic), ebp);
2405 /* if pointer get */
2406 if (POINTER_GET (ic) &&
2407 !isOperandInFarSpace (IC_RESULT (ic)) &&
2408 !OP_SYMBOL (IC_LEFT (ic))->remat &&
2409 !IS_OP_RUONLY (IC_RESULT (ic)) &&
2410 getSize (aggrToPtr (operandType (IC_LEFT (ic)), FALSE)) > 1)
2412 packRegsForOneuse (ic, IC_LEFT (ic), ebp);
2415 /* if this is cast for intergral promotion then
2416 check if only use of the definition of the
2417 operand being casted/ if yes then replace
2418 the result of that arithmetic operation with
2419 this result and get rid of the cast */
2422 sym_link *fromType = operandType (IC_RIGHT (ic));
2423 sym_link *toType = operandType (IC_LEFT (ic));
2425 if (IS_INTEGRAL (fromType) && IS_INTEGRAL (toType) &&
2426 getSize (fromType) != getSize (toType) &&
2427 SPEC_USIGN (fromType) == SPEC_USIGN (toType))
2430 iCode *dic = packRegsForOneuse (ic, IC_RIGHT (ic), ebp);
2433 if (IS_ARITHMETIC_OP (dic))
2435 IC_RESULT (dic) = IC_RESULT (ic);
2436 remiCodeFromeBBlock (ebp, ic);
2437 hTabDeleteItem (&iCodehTab, ic->key, ic, DELETE_ITEM, NULL);
2438 OP_DEFS (IC_RESULT (dic)) = bitVectSetBit (OP_DEFS (IC_RESULT (dic)), dic->key);
2442 OP_SYMBOL (IC_RIGHT (ic))->ruonly = 0;
2448 /* if the type from and type to are the same
2449 then if this is the only use then packit */
2450 if (compareType (operandType (IC_RIGHT (ic)),
2451 operandType (IC_LEFT (ic))) == 1)
2453 iCode *dic = packRegsForOneuse (ic, IC_RIGHT (ic), ebp);
2456 IC_RESULT (dic) = IC_RESULT (ic);
2457 remiCodeFromeBBlock (ebp, ic);
2458 hTabDeleteItem (&iCodehTab, ic->key, ic, DELETE_ITEM, NULL);
2459 OP_DEFS (IC_RESULT (dic)) = bitVectSetBit (OP_DEFS (IC_RESULT (dic)), dic->key);
2467 iTempNN := (some variable in farspace) V1
2472 if (ic->op == IPUSH)
2474 packForPush (ic, ebp);
2478 /* pack registers for accumulator use, when the
2479 result of an arithmetic or bit wise operation
2480 has only one use, that use is immediately following
2481 the defintion and the using iCode has only one
2482 operand or has two operands but one is literal &
2483 the result of that operation is not on stack then
2484 we can leave the result of this operation in acc:b
2486 if ((IS_ARITHMETIC_OP (ic)
2488 || IS_BITWISE_OP (ic)
2490 || ic->op == LEFT_OP || ic->op == RIGHT_OP
2493 IS_ITEMP (IC_RESULT (ic)) &&
2494 getSize (operandType (IC_RESULT (ic))) <= 2)
2496 packRegsForAccUse (ic);
2501 /*-----------------------------------------------------------------*/
2502 /* assignRegisters - assigns registers to each live range as need */
2503 /*-----------------------------------------------------------------*/
2505 ds390_assignRegisters (eBBlock ** ebbs, int count)
2510 setToNull ((void *) &_G.funcrUsed);
2511 ds390_ptrRegReq = _G.stackExtend = _G.dataExtend = 0;
2514 /* change assignments this will remove some
2515 live ranges reducing some register pressure */
2516 for (i = 0; i < count; i++)
2517 packRegisters (ebbs[i]);
2519 if (options.dump_pack)
2520 dumpEbbsToFileExt (DUMP_PACK, ebbs, count);
2522 /* first determine for each live range the number of
2523 registers & the type of registers required for each */
2526 /* and serially allocate registers */
2527 serialRegAssign (ebbs, count);
2529 /* if stack was extended then tell the user */
2532 /* werror(W_TOOMANY_SPILS,"stack", */
2533 /* _G.stackExtend,currFunc->name,""); */
2539 /* werror(W_TOOMANY_SPILS,"data space", */
2540 /* _G.dataExtend,currFunc->name,""); */
2544 /* after that create the register mask
2545 for each of the instruction */
2546 createRegMask (ebbs, count);
2548 /* redo that offsets for stacked automatic variables */
2549 redoStackOffsets ();
2551 if (options.dump_rassgn)
2552 dumpEbbsToFileExt (DUMP_RASSGN, ebbs, count);
2554 /* do the overlaysegment stuff SDCCmem.c */
2555 doOverlays (ebbs, count);
2557 /* now get back the chain */
2558 ic = iCodeLabelOptimize (iCodeFromeBBlock (ebbs, count));
2563 /* free up any _G.stackSpil locations allocated */
2564 applyToSet (_G.stackSpil, deallocStackSpil);
2566 setToNull ((void **) &_G.stackSpil);
2567 setToNull ((void **) &_G.spiltSet);
2568 /* mark all registers as free */