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 /*-----------------------------------------------------------------*/
39 extern void gen51Code (iCode *);
48 bitVect *totRegAssigned; /* final set of LRs that got into registers */
51 bitVect *funcrUsed; /* registers used in a function */
57 /* Shared with gen.c */
58 int mcs51_ptrRegReq; /* one byte pointer register required */
64 {REG_GPR, R2_IDX, REG_GPR, "r2", "ar2", "0", 2, 1},
65 {REG_GPR, R3_IDX, REG_GPR, "r3", "ar3", "0", 3, 1},
66 {REG_GPR, R4_IDX, REG_GPR, "r4", "ar4", "0", 4, 1},
67 {REG_GPR, R5_IDX, REG_GPR, "r5", "ar5", "0", 5, 1},
68 {REG_GPR, R6_IDX, REG_GPR, "r6", "ar6", "0", 6, 1},
69 {REG_GPR, R7_IDX, REG_GPR, "r7", "ar7", "0", 7, 1},
70 {REG_PTR, R0_IDX, REG_PTR, "r0", "ar0", "0", 0, 1},
71 {REG_PTR, R1_IDX, REG_PTR, "r1", "ar1", "0", 1, 1},
72 {REG_GPR, X8_IDX, REG_GPR, "x8", "x8", "xreg", 0, 1},
73 {REG_GPR, X9_IDX, REG_GPR, "x9", "x9", "xreg", 1, 1},
74 {REG_GPR, X10_IDX, REG_GPR, "x10", "x10", "xreg", 2, 1},
75 {REG_GPR, X11_IDX, REG_GPR, "x11", "x11", "xreg", 3, 1},
76 {REG_GPR, X12_IDX, REG_GPR, "x12", "x12", "xreg", 4, 1},
77 {REG_CND, CND_IDX, REG_CND, "C", "C", "xreg", 0, 1},
80 static void spillThis (symbol *);
81 static void freeAllRegs ();
83 /*-----------------------------------------------------------------*/
84 /* allocReg - allocates register of given type */
85 /*-----------------------------------------------------------------*/
91 for (i = 0; i < mcs51_nRegs; i++)
94 /* if type is given as 0 then any
95 free register will do */
99 regs8051[i].isFree = 0;
102 bitVectSetBit (currFunc->regsUsed, i);
105 /* other wise look for specific type
107 if (regs8051[i].isFree &&
108 regs8051[i].type == type)
110 regs8051[i].isFree = 0;
113 bitVectSetBit (currFunc->regsUsed, i);
120 /*-----------------------------------------------------------------*/
121 /* mcs51_regWithIdx - returns pointer to register wit index number */
122 /*-----------------------------------------------------------------*/
124 mcs51_regWithIdx (int idx)
128 for (i = 0; i < mcs51_nRegs; i++)
129 if (regs8051[i].rIdx == idx)
132 werror (E_INTERNAL_ERROR, __FILE__, __LINE__,
133 "regWithIdx not found");
137 /*-----------------------------------------------------------------*/
138 /* freeReg - frees a register */
139 /*-----------------------------------------------------------------*/
145 werror (E_INTERNAL_ERROR, __FILE__, __LINE__,
146 "freeReg - Freeing NULL register");
154 /*-----------------------------------------------------------------*/
155 /* nFreeRegs - returns number of free registers */
156 /*-----------------------------------------------------------------*/
163 for (i = 0; i < mcs51_nRegs; i++)
164 if (regs8051[i].isFree && regs8051[i].type == type)
169 /*-----------------------------------------------------------------*/
170 /* nfreeRegsType - free registers with type */
171 /*-----------------------------------------------------------------*/
173 nfreeRegsType (int type)
178 if ((nfr = nFreeRegs (type)) == 0)
179 return nFreeRegs (REG_GPR);
182 return nFreeRegs (type);
185 /*-----------------------------------------------------------------*/
186 /* useReg - marks a register as used */
187 /*-----------------------------------------------------------------*/
194 /*-----------------------------------------------------------------*/
195 /* allDefsOutOfRange - all definitions are out of a range */
196 /*-----------------------------------------------------------------*/
198 allDefsOutOfRange (bitVect * defs, int fseq, int toseq)
205 for (i = 0; i < defs->size; i++)
209 if (bitVectBitValue (defs, i) &&
210 (ic = hTabItemWithKey (iCodehTab, i)) &&
211 (ic->seq >= fseq && ic->seq <= toseq))
220 /*-----------------------------------------------------------------*/
221 /* computeSpillable - given a point find the spillable live ranges */
222 /*-----------------------------------------------------------------*/
224 computeSpillable (iCode * ic)
228 /* spillable live ranges are those that are live at this
229 point . the following categories need to be subtracted
231 a) - those that are already spilt
232 b) - if being used by this one
233 c) - defined by this one */
235 spillable = bitVectCopy (ic->rlive);
237 bitVectCplAnd (spillable, _G.spiltSet); /* those already spilt */
239 bitVectCplAnd (spillable, ic->uses); /* used in this one */
240 bitVectUnSetBit (spillable, ic->defKey);
241 spillable = bitVectIntersect (spillable, _G.regAssigned);
246 /*-----------------------------------------------------------------*/
247 /* noSpilLoc - return true if a variable has no spil location */
248 /*-----------------------------------------------------------------*/
250 noSpilLoc (symbol * sym, eBBlock * ebp, iCode * ic)
252 return (sym->usl.spillLoc ? 0 : 1);
255 /*-----------------------------------------------------------------*/
256 /* hasSpilLoc - will return 1 if the symbol has spil location */
257 /*-----------------------------------------------------------------*/
259 hasSpilLoc (symbol * sym, eBBlock * ebp, iCode * ic)
261 return (sym->usl.spillLoc ? 1 : 0);
264 /*-----------------------------------------------------------------*/
265 /* directSpilLoc - will return 1 if the splilocation is in direct */
266 /*-----------------------------------------------------------------*/
268 directSpilLoc (symbol * sym, eBBlock * ebp, iCode * ic)
270 if (sym->usl.spillLoc &&
271 (IN_DIRSPACE (SPEC_OCLS (sym->usl.spillLoc->etype))))
277 /*-----------------------------------------------------------------*/
278 /* hasSpilLocnoUptr - will return 1 if the symbol has spil location */
279 /* but is not used as a pointer */
280 /*-----------------------------------------------------------------*/
282 hasSpilLocnoUptr (symbol * sym, eBBlock * ebp, iCode * ic)
284 return ((sym->usl.spillLoc && !sym->uptr) ? 1 : 0);
287 /*-----------------------------------------------------------------*/
288 /* rematable - will return 1 if the remat flag is set */
289 /*-----------------------------------------------------------------*/
291 rematable (symbol * sym, eBBlock * ebp, iCode * ic)
296 /*-----------------------------------------------------------------*/
297 /* notUsedInBlock - not used in this block */
298 /*-----------------------------------------------------------------*/
300 notUsedInBlock (symbol * sym, eBBlock * ebp, iCode * ic)
302 return (!bitVectBitsInCommon (sym->defs, ebp->usesDefs) &&
303 allDefsOutOfRange (sym->defs, ebp->fSeq, ebp->lSeq));
304 /* return (!bitVectBitsInCommon(sym->defs,ebp->usesDefs)); */
307 /*-----------------------------------------------------------------*/
308 /* notUsedInRemaining - not used or defined in remain of the block */
309 /*-----------------------------------------------------------------*/
311 notUsedInRemaining (symbol * sym, eBBlock * ebp, iCode * ic)
313 return ((usedInRemaining (operandFromSymbol (sym), ic) ? 0 : 1) &&
314 allDefsOutOfRange (sym->defs, ebp->fSeq, ebp->lSeq));
317 /*-----------------------------------------------------------------*/
318 /* allLRs - return true for all */
319 /*-----------------------------------------------------------------*/
321 allLRs (symbol * sym, eBBlock * ebp, iCode * ic)
326 /*-----------------------------------------------------------------*/
327 /* liveRangesWith - applies function to a given set of live range */
328 /*-----------------------------------------------------------------*/
330 liveRangesWith (bitVect * lrs, int (func) (symbol *, eBBlock *, iCode *),
331 eBBlock * ebp, iCode * ic)
336 if (!lrs || !lrs->size)
339 for (i = 1; i < lrs->size; i++)
342 if (!bitVectBitValue (lrs, i))
345 /* if we don't find it in the live range
346 hash table we are in serious trouble */
347 if (!(sym = hTabItemWithKey (liveRanges, i)))
349 werror (E_INTERNAL_ERROR, __FILE__, __LINE__,
350 "liveRangesWith could not find liveRange");
354 if (func (sym, ebp, ic) && bitVectBitValue (_G.regAssigned, sym->key))
355 addSetHead (&rset, sym);
362 /*-----------------------------------------------------------------*/
363 /* leastUsedLR - given a set determines which is the least used */
364 /*-----------------------------------------------------------------*/
366 leastUsedLR (set * sset)
368 symbol *sym = NULL, *lsym = NULL;
370 sym = lsym = setFirstItem (sset);
375 for (; lsym; lsym = setNextItem (sset))
378 /* if usage is the same then prefer
379 the spill the smaller of the two */
380 if (lsym->used == sym->used)
381 if (getSize (lsym->type) < getSize (sym->type))
385 if (lsym->used < sym->used)
390 setToNull ((void **) &sset);
395 /*-----------------------------------------------------------------*/
396 /* noOverLap - will iterate through the list looking for over lap */
397 /*-----------------------------------------------------------------*/
399 noOverLap (set * itmpStack, symbol * fsym)
404 for (sym = setFirstItem (itmpStack); sym;
405 sym = setNextItem (itmpStack))
407 if (bitVectBitValue(sym->clashes,fsym->key)) return 0;
413 /*-----------------------------------------------------------------*/
414 /* isFree - will return 1 if the a free spil location is found */
415 /*-----------------------------------------------------------------*/
420 V_ARG (symbol **, sloc);
421 V_ARG (symbol *, fsym);
423 /* if already found */
427 /* if it is free && and the itmp assigned to
428 this does not have any overlapping live ranges
429 with the one currently being assigned and
430 the size can be accomodated */
432 noOverLap (sym->usl.itmpStack, fsym) &&
433 getSize (sym->type) >= getSize (fsym->type))
442 /*-----------------------------------------------------------------*/
443 /* spillLRWithPtrReg :- will spil those live ranges which use PTR */
444 /*-----------------------------------------------------------------*/
446 spillLRWithPtrReg (symbol * forSym)
452 if (!_G.regAssigned ||
453 bitVectIsZero (_G.regAssigned))
456 r0 = mcs51_regWithIdx (R0_IDX);
457 r1 = mcs51_regWithIdx (R1_IDX);
459 /* for all live ranges */
460 for (lrsym = hTabFirstItem (liveRanges, &k); lrsym;
461 lrsym = hTabNextItem (liveRanges, &k))
465 /* if no registers assigned to it or spilt */
466 /* if it does not overlap with this then
467 not need to spill it */
469 if (lrsym->isspilt || !lrsym->nRegs ||
470 (lrsym->liveTo < forSym->liveFrom))
473 /* go thru the registers : if it is either
474 r0 or r1 then spil it */
475 for (j = 0; j < lrsym->nRegs; j++)
476 if (lrsym->regs[j] == r0 ||
477 lrsym->regs[j] == r1)
486 /*-----------------------------------------------------------------*/
487 /* createStackSpil - create a location on the stack to spil */
488 /*-----------------------------------------------------------------*/
490 createStackSpil (symbol * sym)
493 int useXstack, model;
497 /* first go try and find a free one that is already
498 existing on the stack */
499 if (applyToSet (_G.stackSpil, isFree, &sloc, sym))
501 /* found a free one : just update & return */
502 sym->usl.spillLoc = sloc;
505 addSetHead (&sloc->usl.itmpStack, sym);
509 /* could not then have to create one , this is the hard part
510 we need to allocate this on the stack : this is really a
511 hack!! but cannot think of anything better at this time */
513 if (sprintf (slocBuffer, "sloc%d", _G.slocNum++) >= sizeof (slocBuffer))
515 fprintf (stderr, "***Internal error: slocBuffer overflowed: %s:%d\n",
520 sloc = newiTemp (slocBuffer);
522 /* set the type to the spilling symbol */
523 sloc->type = copyLinkChain (sym->type);
524 sloc->etype = getSpec (sloc->type);
525 SPEC_SCLS (sloc->etype) = S_DATA;
526 SPEC_EXTR (sloc->etype) = 0;
527 SPEC_STAT (sloc->etype) = 0;
528 SPEC_VOLATILE(sloc->etype) = 0;
529 SPEC_ABSA(sloc->etype) = 0;
531 /* we don't allow it to be allocated`
532 onto the external stack since : so we
533 temporarily turn it off ; we also
534 turn off memory model to prevent
535 the spil from going to the external storage
538 useXstack = options.useXstack;
539 model = options.model;
540 /* noOverlay = options.noOverlay; */
541 /* options.noOverlay = 1; */
542 options.model = options.useXstack = 0;
546 options.useXstack = useXstack;
547 options.model = model;
548 /* options.noOverlay = noOverlay; */
549 sloc->isref = 1; /* to prevent compiler warning */
551 /* if it is on the stack then update the stack */
552 if (IN_STACK (sloc->etype))
554 currFunc->stack += getSize (sloc->type);
555 _G.stackExtend += getSize (sloc->type);
558 _G.dataExtend += getSize (sloc->type);
560 /* add it to the _G.stackSpil set */
561 addSetHead (&_G.stackSpil, sloc);
562 sym->usl.spillLoc = sloc;
565 /* add it to the set of itempStack set
566 of the spill location */
567 addSetHead (&sloc->usl.itmpStack, sym);
571 /*-----------------------------------------------------------------*/
572 /* isSpiltOnStack - returns true if the spil location is on stack */
573 /*-----------------------------------------------------------------*/
575 isSpiltOnStack (symbol * sym)
585 /* if (sym->_G.stackSpil) */
588 if (!sym->usl.spillLoc)
591 etype = getSpec (sym->usl.spillLoc->type);
592 if (IN_STACK (etype))
598 /*-----------------------------------------------------------------*/
599 /* spillThis - spils a specific operand */
600 /*-----------------------------------------------------------------*/
602 spillThis (symbol * sym)
605 /* if this is rematerializable or has a spillLocation
606 we are okay, else we need to create a spillLocation
608 if (!(sym->remat || sym->usl.spillLoc))
609 createStackSpil (sym);
612 /* mark it has spilt & put it in the spilt set */
613 sym->isspilt = sym->spillA = 1;
614 _G.spiltSet = bitVectSetBit (_G.spiltSet, sym->key);
616 bitVectUnSetBit (_G.regAssigned, sym->key);
617 bitVectUnSetBit (_G.totRegAssigned, sym->key);
619 for (i = 0; i < sym->nRegs; i++)
623 freeReg (sym->regs[i]);
627 /* if spilt on stack then free up r0 & r1
628 if they could have been assigned to some
630 if (!mcs51_ptrRegReq && isSpiltOnStack (sym))
633 spillLRWithPtrReg (sym);
636 if (sym->usl.spillLoc && !sym->remat)
637 sym->usl.spillLoc->allocreq++;
641 /*-----------------------------------------------------------------*/
642 /* selectSpil - select a iTemp to spil : rather a simple procedure */
643 /*-----------------------------------------------------------------*/
645 selectSpil (iCode * ic, eBBlock * ebp, symbol * forSym)
647 bitVect *lrcs = NULL;
651 /* get the spillable live ranges */
652 lrcs = computeSpillable (ic);
654 /* get all live ranges that are rematerizable */
655 if ((selectS = liveRangesWith (lrcs, rematable, ebp, ic)))
658 /* return the least used of these */
659 return leastUsedLR (selectS);
662 /* get live ranges with spillLocations in direct space */
663 if ((selectS = liveRangesWith (lrcs, directSpilLoc, ebp, ic)))
665 sym = leastUsedLR (selectS);
666 strcpy (sym->rname, (sym->usl.spillLoc->rname[0] ?
667 sym->usl.spillLoc->rname :
668 sym->usl.spillLoc->name));
670 /* mark it as allocation required */
671 sym->usl.spillLoc->allocreq++;
675 /* if the symbol is local to the block then */
676 if (forSym->liveTo < ebp->lSeq)
679 /* check if there are any live ranges allocated
680 to registers that are not used in this block */
681 if (!_G.blockSpil && (selectS = liveRangesWith (lrcs, notUsedInBlock, ebp, ic)))
683 sym = leastUsedLR (selectS);
684 /* if this is not rematerializable */
693 /* check if there are any live ranges that not
694 used in the remainder of the block */
695 if (!_G.blockSpil && (selectS = liveRangesWith (lrcs, notUsedInRemaining, ebp, ic)))
697 sym = leastUsedLR (selectS);
710 /* find live ranges with spillocation && not used as pointers */
711 if ((selectS = liveRangesWith (lrcs, hasSpilLocnoUptr, ebp, ic)))
714 sym = leastUsedLR (selectS);
715 /* mark this as allocation required */
716 sym->usl.spillLoc->allocreq++;
720 /* find live ranges with spillocation */
721 if ((selectS = liveRangesWith (lrcs, hasSpilLoc, ebp, ic)))
724 sym = leastUsedLR (selectS);
725 sym->usl.spillLoc->allocreq++;
729 /* couldn't find then we need to create a spil
730 location on the stack , for which one? the least
732 if ((selectS = liveRangesWith (lrcs, noSpilLoc, ebp, ic)))
735 /* return a created spil location */
736 sym = createStackSpil (leastUsedLR (selectS));
737 sym->usl.spillLoc->allocreq++;
741 /* this is an extreme situation we will spill
742 this one : happens very rarely but it does happen */
748 /*-----------------------------------------------------------------*/
749 /* spilSomething - spil some variable & mark registers as free */
750 /*-----------------------------------------------------------------*/
752 spilSomething (iCode * ic, eBBlock * ebp, symbol * forSym)
757 /* get something we can spil */
758 ssym = selectSpil (ic, ebp, forSym);
760 /* mark it as spilt */
761 ssym->isspilt = ssym->spillA = 1;
762 _G.spiltSet = bitVectSetBit (_G.spiltSet, ssym->key);
764 /* mark it as not register assigned &
765 take it away from the set */
766 bitVectUnSetBit (_G.regAssigned, ssym->key);
767 bitVectUnSetBit (_G.totRegAssigned, ssym->key);
769 /* mark the registers as free */
770 for (i = 0; i < ssym->nRegs; i++)
772 freeReg (ssym->regs[i]);
774 /* if spilt on stack then free up r0 & r1
775 if they could have been assigned to as gprs */
776 if (!mcs51_ptrRegReq && isSpiltOnStack (ssym))
779 spillLRWithPtrReg (ssym);
782 /* if this was a block level spil then insert push & pop
783 at the start & end of block respectively */
786 iCode *nic = newiCode (IPUSH, operandFromSymbol (ssym), NULL);
787 /* add push to the start of the block */
788 addiCodeToeBBlock (ebp, nic, (ebp->sch->op == LABEL ?
789 ebp->sch->next : ebp->sch));
790 nic = newiCode (IPOP, operandFromSymbol (ssym), NULL);
791 /* add pop to the end of the block */
792 addiCodeToeBBlock (ebp, nic, NULL);
795 /* if spilt because not used in the remainder of the
796 block then add a push before this instruction and
797 a pop at the end of the block */
798 if (ssym->remainSpil)
801 iCode *nic = newiCode (IPUSH, operandFromSymbol (ssym), NULL);
802 /* add push just before this instruction */
803 addiCodeToeBBlock (ebp, nic, ic);
805 nic = newiCode (IPOP, operandFromSymbol (ssym), NULL);
806 /* add pop to the end of the block */
807 addiCodeToeBBlock (ebp, nic, NULL);
816 /*-----------------------------------------------------------------*/
817 /* getRegPtr - will try for PTR if not a GPR type if not spil */
818 /*-----------------------------------------------------------------*/
820 getRegPtr (iCode * ic, eBBlock * ebp, symbol * sym)
825 /* try for a ptr type */
826 if ((reg = allocReg (REG_PTR)))
829 /* try for gpr type */
830 if ((reg = allocReg (REG_GPR)))
833 /* we have to spil */
834 if (!spilSomething (ic, ebp, sym))
837 /* this looks like an infinite loop but
838 in really selectSpil will abort */
842 /*-----------------------------------------------------------------*/
843 /* getRegGpr - will try for GPR if not spil */
844 /*-----------------------------------------------------------------*/
846 getRegGpr (iCode * ic, eBBlock * ebp, symbol * sym)
851 /* try for gpr type */
852 if ((reg = allocReg (REG_GPR)))
855 if (!mcs51_ptrRegReq)
856 if ((reg = allocReg (REG_PTR)))
859 /* we have to spil */
860 if (!spilSomething (ic, ebp, sym))
863 /* this looks like an infinite loop but
864 in really selectSpil will abort */
868 /*-----------------------------------------------------------------*/
869 /* getRegPtrNoSpil - get it cannot split */
870 /*-----------------------------------------------------------------*/
871 static regs *getRegPtrNoSpil()
875 /* try for a ptr type */
876 if ((reg = allocReg (REG_PTR)))
879 /* try for gpr type */
880 if ((reg = allocReg (REG_GPR)))
886 /*-----------------------------------------------------------------*/
887 /* getRegGprNoSpil - get it cannot split */
888 /*-----------------------------------------------------------------*/
889 static regs *getRegGprNoSpil()
893 if ((reg = allocReg (REG_GPR)))
896 if (!mcs51_ptrRegReq)
897 if ((reg = allocReg (REG_PTR)))
903 /*-----------------------------------------------------------------*/
904 /* symHasReg - symbol has a given register */
905 /*-----------------------------------------------------------------*/
907 symHasReg (symbol * sym, regs * reg)
911 for (i = 0; i < sym->nRegs; i++)
912 if (sym->regs[i] == reg)
918 /*-----------------------------------------------------------------*/
919 /* deassignLRs - check the live to and if they have registers & are */
920 /* not spilt then free up the registers */
921 /*-----------------------------------------------------------------*/
923 deassignLRs (iCode * ic, eBBlock * ebp)
929 for (sym = hTabFirstItem (liveRanges, &k); sym;
930 sym = hTabNextItem (liveRanges, &k))
934 /* if it does not end here */
935 if (sym->liveTo > ic->seq)
938 /* if it was spilt on stack then we can
939 mark the stack spil location as free */
944 sym->usl.spillLoc->isFree = 1;
950 if (!bitVectBitValue (_G.regAssigned, sym->key))
953 /* special case check if this is an IFX &
954 the privious one was a pop and the
955 previous one was not spilt then keep track
957 if (ic->op == IFX && ic->prev &&
958 ic->prev->op == IPOP &&
959 !ic->prev->parmPush &&
960 !OP_SYMBOL (IC_LEFT (ic->prev))->isspilt)
961 psym = OP_SYMBOL (IC_LEFT (ic->prev));
967 bitVectUnSetBit (_G.regAssigned, sym->key);
969 /* if the result of this one needs registers
970 and does not have it then assign it right
972 if (IC_RESULT (ic) &&
973 !(SKIP_IC2 (ic) || /* not a special icode */
974 ic->op == JUMPTABLE ||
980 (result = OP_SYMBOL (IC_RESULT (ic))) && /* has a result */
981 result->liveTo > ic->seq && /* and will live beyond this */
982 result->liveTo <= ebp->lSeq && /* does not go beyond this block */
983 result->regType == sym->regType && /* same register types */
984 result->nRegs && /* which needs registers */
985 !result->isspilt && /* and does not already have them */
987 !bitVectBitValue (_G.regAssigned, result->key) &&
988 /* the number of free regs + number of regs in this LR
989 can accomodate the what result Needs */
990 ((nfreeRegsType (result->regType) +
991 sym->nRegs) >= result->nRegs)
995 for (i = 0; i < result->nRegs; i++)
997 result->regs[i] = sym->regs[i];
999 result->regs[i] = getRegGpr (ic, ebp, result);
1001 _G.regAssigned = bitVectSetBit (_G.regAssigned, result->key);
1002 _G.totRegAssigned = bitVectSetBit (_G.totRegAssigned, result->key);
1006 /* free the remaining */
1007 for (; i < sym->nRegs; i++)
1011 if (!symHasReg (psym, sym->regs[i]))
1012 freeReg (sym->regs[i]);
1015 freeReg (sym->regs[i]);
1022 /*-----------------------------------------------------------------*/
1023 /* reassignLR - reassign this to registers */
1024 /*-----------------------------------------------------------------*/
1026 reassignLR (operand * op)
1028 symbol *sym = OP_SYMBOL (op);
1031 /* not spilt any more */
1032 sym->isspilt = sym->spillA = sym->blockSpil = sym->remainSpil = 0;
1033 bitVectUnSetBit (_G.spiltSet, sym->key);
1035 _G.regAssigned = bitVectSetBit (_G.regAssigned, sym->key);
1036 _G.totRegAssigned = bitVectSetBit (_G.totRegAssigned, sym->key);
1040 for (i = 0; i < sym->nRegs; i++)
1041 sym->regs[i]->isFree = 0;
1044 /*-----------------------------------------------------------------*/
1045 /* willCauseSpill - determines if allocating will cause a spill */
1046 /*-----------------------------------------------------------------*/
1048 willCauseSpill (int nr, int rt)
1050 /* first check if there are any avlb registers
1051 of te type required */
1054 /* special case for pointer type
1055 if pointer type not avlb then
1056 check for type gpr */
1057 if (nFreeRegs (rt) >= nr)
1059 if (nFreeRegs (REG_GPR) >= nr)
1064 if (mcs51_ptrRegReq)
1066 if (nFreeRegs (rt) >= nr)
1071 if (nFreeRegs (REG_PTR) +
1072 nFreeRegs (REG_GPR) >= nr)
1077 /* it will cause a spil */
1081 /*-----------------------------------------------------------------*/
1082 /* positionRegs - the allocator can allocate same registers to res- */
1083 /* ult and operand, if this happens make sure they are in the same */
1084 /* position as the operand otherwise chaos results */
1085 /*-----------------------------------------------------------------*/
1087 positionRegs (symbol * result, symbol * opsym)
1089 int count = min (result->nRegs, opsym->nRegs);
1090 int i, j = 0, shared = 0;
1093 /* if the result has been spilt then cannot share */
1098 /* first make sure that they actually share */
1099 for (i = 0; i < count; i++)
1101 for (j = 0; j < count; j++)
1103 if (result->regs[i] == opsym->regs[j] && i != j)
1113 regs *tmp = result->regs[i];
1114 result->regs[i] = result->regs[j];
1115 result->regs[j] = tmp;
1122 /*-----------------------------------------------------------------*/
1123 /* serialRegAssign - serially allocate registers to the variables */
1124 /*-----------------------------------------------------------------*/
1126 serialRegAssign (eBBlock ** ebbs, int count)
1130 /* for all blocks */
1131 for (i = 0; i < count; i++) {
1135 if (ebbs[i]->noPath &&
1136 (ebbs[i]->entryLabel != entryLabel &&
1137 ebbs[i]->entryLabel != returnLabel))
1140 /* of all instructions do */
1141 for (ic = ebbs[i]->sch; ic; ic = ic->next) {
1143 /* if this is an ipop that means some live
1144 range will have to be assigned again */
1146 reassignLR (IC_LEFT (ic));
1148 /* if result is present && is a true symbol */
1149 if (IC_RESULT (ic) && ic->op != IFX &&
1150 IS_TRUE_SYMOP (IC_RESULT (ic)))
1151 OP_SYMBOL (IC_RESULT (ic))->allocreq++;
1153 /* take away registers from live
1154 ranges that end at this instruction */
1155 deassignLRs (ic, ebbs[i]);
1157 /* some don't need registers */
1158 if (SKIP_IC2 (ic) ||
1159 ic->op == JUMPTABLE ||
1163 (IC_RESULT (ic) && POINTER_SET (ic)))
1166 /* now we need to allocate registers
1167 only for the result */
1168 if (IC_RESULT (ic)) {
1169 symbol *sym = OP_SYMBOL (IC_RESULT (ic));
1175 /* if it does not need or is spilt
1176 or is already assigned to registers
1177 or will not live beyond this instructions */
1180 bitVectBitValue (_G.regAssigned, sym->key) ||
1181 sym->liveTo <= ic->seq)
1184 /* if some liverange has been spilt at the block level
1185 and this one live beyond this block then spil this
1187 if (_G.blockSpil && sym->liveTo > ebbs[i]->lSeq) {
1191 /* if trying to allocate this will cause
1192 a spill and there is nothing to spill
1193 or this one is rematerializable then
1195 willCS = willCauseSpill (sym->nRegs, sym->regType);
1196 spillable = computeSpillable (ic);
1197 if (sym->remat || (willCS && bitVectIsZero (spillable))) {
1202 /* if it has a spillocation & is used less than
1203 all other live ranges then spill this */
1205 if (sym->usl.spillLoc) {
1206 symbol *leastUsed = leastUsedLR (liveRangesWith (spillable,
1207 allLRs, ebbs[i], ic));
1208 if (leastUsed && leastUsed->used > sym->used) {
1213 /* if none of the liveRanges have a spillLocation then better
1214 to spill this one than anything else already assigned to registers */
1215 if (liveRangesWith(spillable,noSpilLoc,ebbs[i],ic)) {
1216 /* if this is local to this block then we might find a block spil */
1217 if (!(sym->liveFrom >= ebbs[i]->fSeq && sym->liveTo <= ebbs[i]->lSeq)) {
1224 /* if we need ptr regs for the right side
1226 if (POINTER_GET (ic) && IS_SYMOP (IC_LEFT (ic))
1227 && getSize (OP_SYMBOL (IC_LEFT (ic))->type) <= (unsigned int) PTRSIZE) {
1231 /* else we assign registers to it */
1232 _G.regAssigned = bitVectSetBit (_G.regAssigned, sym->key);
1233 _G.totRegAssigned = bitVectSetBit (_G.totRegAssigned, sym->key);
1235 for (j = 0; j < sym->nRegs; j++) {
1236 if (sym->regType == REG_PTR)
1237 sym->regs[j] = getRegPtr (ic, ebbs[i], sym);
1239 sym->regs[j] = getRegGpr (ic, ebbs[i], sym);
1241 /* if the allocation failed which means
1242 this was spilt then break */
1243 if (!sym->regs[j]) {
1248 /* if it shares registers with operands make sure
1249 that they are in the same position */
1250 if (IC_LEFT (ic) && IS_SYMOP (IC_LEFT (ic)) &&
1251 OP_SYMBOL (IC_LEFT (ic))->nRegs && ic->op != '=') {
1252 positionRegs (OP_SYMBOL (IC_RESULT (ic)),
1253 OP_SYMBOL (IC_LEFT (ic)));
1255 /* do the same for the right operand */
1256 if (IC_RIGHT (ic) && IS_SYMOP (IC_RIGHT (ic)) &&
1257 OP_SYMBOL (IC_RIGHT (ic))->nRegs) {
1258 positionRegs (OP_SYMBOL (IC_RESULT (ic)),
1259 OP_SYMBOL (IC_RIGHT (ic)));
1272 /*-----------------------------------------------------------------*/
1273 /* fillGaps - Try to fill in the Gaps left by Pass1 */
1274 /*-----------------------------------------------------------------*/
1275 static void fillGaps()
1280 if (getenv("DISABLE_FILL_GAPS")) return;
1282 /* look for livernages that was spilt by the allocator */
1283 for (sym = hTabFirstItem(liveRanges,&key) ; sym ;
1284 sym = hTabNextItem(liveRanges,&key)) {
1289 if (!sym->spillA || !sym->clashes || sym->remat) continue ;
1291 /* find the liveRanges this one clashes with, that are
1292 still assigned to registers & mark the registers as used*/
1293 for ( i = 0 ; i < sym->clashes->size ; i ++) {
1297 if (bitVectBitValue(sym->clashes,i) == 0 || /* those that clash with this */
1298 bitVectBitValue(_G.totRegAssigned,i) == 0) /* and are still assigned to registers */
1301 assert (clr = hTabItemWithKey(liveRanges,i));
1303 /* mark these registers as used */
1304 for (k = 0 ; k < clr->nRegs ; k++ )
1305 useReg(clr->regs[k]);
1308 if (willCauseSpill(sym->nRegs,sym->regType)) {
1309 /* NOPE :( clear all registers & and continue */
1314 /* THERE IS HOPE !!!! */
1315 for (i=0; i < sym->nRegs ; i++ ) {
1316 if (sym->regType == REG_PTR)
1317 sym->regs[i] = getRegPtrNoSpil ();
1319 sym->regs[i] = getRegGprNoSpil ();
1322 /* for all its definitions check if the registers
1323 allocated needs positioning NOTE: we can position
1324 only ONCE if more than One positioning required
1327 for (i = 0 ; i < sym->defs->size ; i++ ) {
1328 if (bitVectBitValue(sym->defs,i)) {
1330 if (!(ic = hTabItemWithKey(iCodehTab,i))) continue ;
1331 if (SKIP_IC(ic)) continue;
1332 assert(isSymbolEqual(sym,OP_SYMBOL(IC_RESULT(ic)))); /* just making sure */
1333 /* if left is assigned to registers */
1334 if (IS_SYMOP(IC_LEFT(ic)) &&
1335 bitVectBitValue(_G.totRegAssigned,OP_SYMBOL(IC_LEFT(ic))->key)) {
1336 pdone += positionRegs(sym,OP_SYMBOL(IC_LEFT(ic)));
1338 if (IS_SYMOP(IC_RIGHT(ic)) &&
1339 bitVectBitValue(_G.totRegAssigned,OP_SYMBOL(IC_RIGHT(ic))->key)) {
1340 pdone += positionRegs(sym,OP_SYMBOL(IC_RIGHT(ic)));
1342 if (pdone > 1) break;
1345 for (i = 0 ; i < sym->uses->size ; i++ ) {
1346 if (bitVectBitValue(sym->uses,i)) {
1348 if (!(ic = hTabItemWithKey(iCodehTab,i))) continue ;
1349 if (SKIP_IC(ic)) continue;
1350 if (!IS_ASSIGN_ICODE(ic)) continue ;
1352 /* if result is assigned to registers */
1353 if (IS_SYMOP(IC_RESULT(ic)) &&
1354 bitVectBitValue(_G.totRegAssigned,OP_SYMBOL(IC_RESULT(ic))->key)) {
1355 pdone += positionRegs(sym,OP_SYMBOL(IC_RESULT(ic)));
1357 if (pdone > 1) break;
1360 /* had to position more than once GIVE UP */
1362 /* UNDO all the changes we made to try this */
1364 for (i=0; i < sym->nRegs ; i++ ) {
1365 sym->regs[i] = NULL;
1368 D(printf ("Fill Gap gave up due to positioning for %s in function %s\n",sym->name, currFunc ? currFunc->name : "UNKNOWN"));
1371 D(printf ("FILLED GAP for %s in function %s\n",sym->name, currFunc ? currFunc->name : "UNKNOWN"));
1372 _G.totRegAssigned = bitVectSetBit(_G.totRegAssigned,sym->key);
1373 sym->isspilt = sym->spillA = 0 ;
1374 sym->usl.spillLoc->allocreq--;
1379 /*-----------------------------------------------------------------*/
1380 /* rUmaskForOp :- returns register mask for an operand */
1381 /*-----------------------------------------------------------------*/
1383 mcs51_rUmaskForOp (operand * op)
1389 /* only temporaries are assigned registers */
1393 sym = OP_SYMBOL (op);
1395 /* if spilt or no registers assigned to it
1397 if (sym->isspilt || !sym->nRegs)
1400 rumask = newBitVect (mcs51_nRegs);
1402 for (j = 0; j < sym->nRegs; j++)
1404 rumask = bitVectSetBit (rumask,
1405 sym->regs[j]->rIdx);
1411 /*-----------------------------------------------------------------*/
1412 /* regsUsedIniCode :- returns bit vector of registers used in iCode */
1413 /*-----------------------------------------------------------------*/
1415 regsUsedIniCode (iCode * ic)
1417 bitVect *rmask = newBitVect (mcs51_nRegs);
1419 /* do the special cases first */
1422 rmask = bitVectUnion (rmask,
1423 mcs51_rUmaskForOp (IC_COND (ic)));
1427 /* for the jumptable */
1428 if (ic->op == JUMPTABLE)
1430 rmask = bitVectUnion (rmask,
1431 mcs51_rUmaskForOp (IC_JTCOND (ic)));
1436 /* of all other cases */
1438 rmask = bitVectUnion (rmask,
1439 mcs51_rUmaskForOp (IC_LEFT (ic)));
1443 rmask = bitVectUnion (rmask,
1444 mcs51_rUmaskForOp (IC_RIGHT (ic)));
1447 rmask = bitVectUnion (rmask,
1448 mcs51_rUmaskForOp (IC_RESULT (ic)));
1454 /*-----------------------------------------------------------------*/
1455 /* createRegMask - for each instruction will determine the regsUsed */
1456 /*-----------------------------------------------------------------*/
1458 createRegMask (eBBlock ** ebbs, int count)
1462 /* for all blocks */
1463 for (i = 0; i < count; i++)
1467 if (ebbs[i]->noPath &&
1468 (ebbs[i]->entryLabel != entryLabel &&
1469 ebbs[i]->entryLabel != returnLabel))
1472 /* for all instructions */
1473 for (ic = ebbs[i]->sch; ic; ic = ic->next)
1478 if (SKIP_IC2 (ic) || !ic->rlive)
1481 /* first mark the registers used in this
1483 ic->rUsed = regsUsedIniCode (ic);
1484 _G.funcrUsed = bitVectUnion (_G.funcrUsed, ic->rUsed);
1486 /* now create the register mask for those
1487 registers that are in use : this is a
1488 super set of ic->rUsed */
1489 ic->rMask = newBitVect (mcs51_nRegs + 1);
1491 /* for all live Ranges alive at this point */
1492 for (j = 1; j < ic->rlive->size; j++)
1497 /* if not alive then continue */
1498 if (!bitVectBitValue (ic->rlive, j))
1501 /* find the live range we are interested in */
1502 if (!(sym = hTabItemWithKey (liveRanges, j)))
1504 werror (E_INTERNAL_ERROR, __FILE__, __LINE__,
1505 "createRegMask cannot find live range");
1509 /* if no register assigned to it */
1510 if (!sym->nRegs || sym->isspilt)
1513 /* for all the registers allocated to it */
1514 for (k = 0; k < sym->nRegs; k++)
1517 bitVectSetBit (ic->rMask, sym->regs[k]->rIdx);
1523 /*-----------------------------------------------------------------*/
1524 /* rematStr - returns the rematerialized string for a remat var */
1525 /*-----------------------------------------------------------------*/
1527 rematStr (symbol * sym)
1530 iCode *ic = sym->rematiCode;
1535 /* if plus or minus print the right hand side */
1536 if (ic->op == '+' || ic->op == '-')
1538 sprintf (s, "0x%04x %c ", (int) operandLitValue (IC_RIGHT (ic)),
1541 ic = OP_SYMBOL (IC_LEFT (ic))->rematiCode;
1545 /* cast then continue */
1546 if (IS_CAST_ICODE(ic)) {
1547 ic = OP_SYMBOL (IC_RIGHT (ic))->rematiCode;
1550 /* we reached the end */
1551 sprintf (s, "%s", OP_SYMBOL (IC_LEFT (ic))->rname);
1558 /*-----------------------------------------------------------------*/
1559 /* regTypeNum - computes the type & number of registers required */
1560 /*-----------------------------------------------------------------*/
1562 regTypeNum (eBBlock *ebbs)
1568 /* for each live range do */
1569 for (sym = hTabFirstItem (liveRanges, &k); sym;
1570 sym = hTabNextItem (liveRanges, &k))
1573 /* if used zero times then no registers needed */
1574 if ((sym->liveTo - sym->liveFrom) == 0)
1578 /* if the live range is a temporary */
1582 /* if the type is marked as a conditional */
1583 if (sym->regType == REG_CND)
1586 /* if used in return only then we don't
1588 if (sym->ruonly || sym->accuse)
1590 if (IS_AGGREGATE (sym->type) || sym->isptr)
1591 sym->type = aggrToPtr (sym->type, FALSE);
1595 /* if the symbol has only one definition &
1596 that definition is a get_pointer */
1597 if (bitVectnBitsOn (sym->defs) == 1 &&
1598 (ic = hTabItemWithKey (iCodehTab,
1599 bitVectFirstBit (sym->defs))) &&
1602 !IS_BITVAR (sym->etype))
1606 /* and that pointer is remat in data space */
1607 if (OP_SYMBOL (IC_LEFT (ic))->remat &&
1608 !IS_CAST_ICODE(OP_SYMBOL (IC_LEFT (ic))->rematiCode) &&
1609 DCL_TYPE (aggrToPtr (operandType(IC_LEFT(ic)), FALSE)) == POINTER)
1611 /* create a psuedo symbol & force a spil */
1612 symbol *psym = newSymbol (rematStr (OP_SYMBOL (IC_LEFT (ic))), 1);
1613 psym->type = sym->type;
1614 psym->etype = sym->etype;
1615 strcpy (psym->rname, psym->name);
1617 sym->usl.spillLoc = psym;
1618 #if 0 // an alternative fix for bug #480076
1619 /* now this is a useless assignment to itself */
1620 remiCodeFromeBBlock (ebbs, ic);
1622 /* now this really is an assignment to itself, make it so;
1623 it will be optimized out later */
1625 IC_RIGHT(ic)=IC_RESULT(ic);
1631 /* if in data space or idata space then try to
1632 allocate pointer register */
1636 /* if not then we require registers */
1637 sym->nRegs = ((IS_AGGREGATE (sym->type) || sym->isptr) ?
1638 getSize (sym->type = aggrToPtr (sym->type, FALSE)) :
1639 getSize (sym->type));
1643 fprintf (stderr, "allocated more than 4 or 0 registers for type ");
1644 printTypeChain (sym->type, stderr);
1645 fprintf (stderr, "\n");
1648 /* determine the type of register required */
1649 if (sym->nRegs == 1 &&
1650 IS_PTR (sym->type) &&
1652 sym->regType = REG_PTR;
1654 sym->regType = REG_GPR;
1658 /* for the first run we don't provide */
1659 /* registers for true symbols we will */
1660 /* see how things go */
1666 /*-----------------------------------------------------------------*/
1667 /* freeAllRegs - mark all registers as free */
1668 /*-----------------------------------------------------------------*/
1674 for (i = 0; i < mcs51_nRegs; i++)
1675 regs8051[i].isFree = 1;
1678 /*-----------------------------------------------------------------*/
1679 /* deallocStackSpil - this will set the stack pointer back */
1680 /*-----------------------------------------------------------------*/
1682 DEFSETFUNC (deallocStackSpil)
1690 /*-----------------------------------------------------------------*/
1691 /* farSpacePackable - returns the packable icode for far variables */
1692 /*-----------------------------------------------------------------*/
1694 farSpacePackable (iCode * ic)
1698 /* go thru till we find a definition for the
1699 symbol on the right */
1700 for (dic = ic->prev; dic; dic = dic->prev)
1702 /* if the definition is a call then no */
1703 if ((dic->op == CALL || dic->op == PCALL) &&
1704 IC_RESULT (dic)->key == IC_RIGHT (ic)->key)
1709 /* if shift by unknown amount then not */
1710 if ((dic->op == LEFT_OP || dic->op == RIGHT_OP) &&
1711 IC_RESULT (dic)->key == IC_RIGHT (ic)->key)
1714 /* if pointer get and size > 1 */
1715 if (POINTER_GET (dic) &&
1716 getSize (aggrToPtr (operandType (IC_LEFT (dic)), FALSE)) > 1)
1719 if (POINTER_SET (dic) &&
1720 getSize (aggrToPtr (operandType (IC_RESULT (dic)), FALSE)) > 1)
1723 /* if any three is a true symbol in far space */
1724 if (IC_RESULT (dic) &&
1725 IS_TRUE_SYMOP (IC_RESULT (dic)) &&
1726 isOperandInFarSpace (IC_RESULT (dic)))
1729 if (IC_RIGHT (dic) &&
1730 IS_TRUE_SYMOP (IC_RIGHT (dic)) &&
1731 isOperandInFarSpace (IC_RIGHT (dic)) &&
1732 !isOperandEqual (IC_RIGHT (dic), IC_RESULT (ic)))
1735 if (IC_LEFT (dic) &&
1736 IS_TRUE_SYMOP (IC_LEFT (dic)) &&
1737 isOperandInFarSpace (IC_LEFT (dic)) &&
1738 !isOperandEqual (IC_LEFT (dic), IC_RESULT (ic)))
1741 if (isOperandEqual (IC_RIGHT (ic), IC_RESULT (dic)))
1743 if ((dic->op == LEFT_OP ||
1744 dic->op == RIGHT_OP ||
1746 IS_OP_LITERAL (IC_RIGHT (dic)))
1756 /*-----------------------------------------------------------------*/
1757 /* packRegsForAssign - register reduction for assignment */
1758 /*-----------------------------------------------------------------*/
1760 packRegsForAssign (iCode * ic, eBBlock * ebp)
1763 //sym_link *etype = operandType (IC_RIGHT (ic));
1765 if (!IS_ITEMP (IC_RIGHT (ic)) ||
1766 OP_SYMBOL (IC_RIGHT (ic))->isind ||
1767 OP_LIVETO (IC_RIGHT (ic)) > ic->seq
1768 /* why? || IS_BITFIELD (etype) */ )
1773 /* if the true symbol is defined in far space or on stack
1774 then we should not since this will increase register pressure */
1775 if (isOperandInFarSpace(IC_RESULT(ic)) && !farSpacePackable(ic)) {
1779 /* find the definition of iTempNN scanning backwards if we find a
1780 a use of the true symbol in before we find the definition then
1782 for (dic = ic->prev; dic; dic = dic->prev)
1784 /* if there is a function call then don't pack it */
1785 if ((dic->op == CALL || dic->op == PCALL))
1794 if (IS_TRUE_SYMOP (IC_RESULT (dic)) &&
1795 IS_OP_VOLATILE (IC_RESULT (dic)))
1801 if (IS_SYMOP (IC_RESULT (dic)) &&
1802 IC_RESULT (dic)->key == IC_RIGHT (ic)->key)
1804 if (POINTER_SET (dic))
1810 if (IS_SYMOP (IC_RIGHT (dic)) &&
1811 (IC_RIGHT (dic)->key == IC_RESULT (ic)->key ||
1812 IC_RIGHT (dic)->key == IC_RIGHT (ic)->key))
1818 if (IS_SYMOP (IC_LEFT (dic)) &&
1819 (IC_LEFT (dic)->key == IC_RESULT (ic)->key ||
1820 IC_LEFT (dic)->key == IC_RIGHT (ic)->key))
1826 if (POINTER_SET (dic) &&
1827 IC_RESULT (dic)->key == IC_RESULT (ic)->key)
1835 return 0; /* did not find */
1837 /* if assignment then check that right is not a bit */
1838 if (ASSIGNMENT (dic) && !POINTER_SET (dic))
1840 sym_link *etype = operandType (IC_RIGHT (dic));
1841 if (IS_BITFIELD (etype))
1844 /* if the result is on stack or iaccess then it must be
1845 the same atleast one of the operands */
1846 if (OP_SYMBOL (IC_RESULT (ic))->onStack ||
1847 OP_SYMBOL (IC_RESULT (ic))->iaccess)
1850 /* the operation has only one symbol
1851 operator then we can pack */
1852 if ((IC_LEFT (dic) && !IS_SYMOP (IC_LEFT (dic))) ||
1853 (IC_RIGHT (dic) && !IS_SYMOP (IC_RIGHT (dic))))
1856 if (!((IC_LEFT (dic) &&
1857 IC_RESULT (ic)->key == IC_LEFT (dic)->key) ||
1859 IC_RESULT (ic)->key == IC_RIGHT (dic)->key)))
1863 /* found the definition */
1864 /* replace the result with the result of */
1865 /* this assignment and remove this assignment */
1866 bitVectUnSetBit(OP_SYMBOL(IC_RESULT(dic))->defs,dic->key);
1867 IC_RESULT (dic) = IC_RESULT (ic);
1869 if (IS_ITEMP (IC_RESULT (dic)) && OP_SYMBOL (IC_RESULT (dic))->liveFrom > dic->seq)
1871 OP_SYMBOL (IC_RESULT (dic))->liveFrom = dic->seq;
1873 /* delete from liverange table also
1874 delete from all the points inbetween and the new
1876 for (sic = dic; sic != ic; sic = sic->next)
1878 bitVectUnSetBit (sic->rlive, IC_RESULT (ic)->key);
1879 if (IS_ITEMP (IC_RESULT (dic)))
1880 bitVectSetBit (sic->rlive, IC_RESULT (dic)->key);
1883 remiCodeFromeBBlock (ebp, ic);
1884 bitVectUnSetBit(OP_SYMBOL(IC_RESULT(ic))->defs,ic->key);
1885 hTabDeleteItem (&iCodehTab, ic->key, ic, DELETE_ITEM, NULL);
1886 OP_DEFS (IC_RESULT (dic)) = bitVectSetBit (OP_DEFS (IC_RESULT (dic)), dic->key);
1891 /*-----------------------------------------------------------------*/
1892 /* findAssignToSym : scanning backwards looks for first assig found */
1893 /*-----------------------------------------------------------------*/
1895 findAssignToSym (operand * op, iCode * ic)
1899 for (dic = ic->prev; dic; dic = dic->prev)
1902 /* if definition by assignment */
1903 if (dic->op == '=' &&
1904 !POINTER_SET (dic) &&
1905 IC_RESULT (dic)->key == op->key
1906 /* && IS_TRUE_SYMOP(IC_RIGHT(dic)) */
1910 /* we are interested only if defined in far space */
1911 /* or in stack space in case of + & - */
1913 /* if assigned to a non-symbol then return
1915 if (!IS_SYMOP (IC_RIGHT (dic)))
1918 /* if the symbol is in far space then
1920 if (isOperandInFarSpace (IC_RIGHT (dic)))
1923 /* for + & - operations make sure that
1924 if it is on the stack it is the same
1925 as one of the three operands */
1926 if ((ic->op == '+' || ic->op == '-') &&
1927 OP_SYMBOL (IC_RIGHT (dic))->onStack)
1930 if (IC_RESULT (ic)->key != IC_RIGHT (dic)->key &&
1931 IC_LEFT (ic)->key != IC_RIGHT (dic)->key &&
1932 IC_RIGHT (ic)->key != IC_RIGHT (dic)->key)
1940 /* if we find an usage then we cannot delete it */
1941 if (IC_LEFT (dic) && IC_LEFT (dic)->key == op->key)
1944 if (IC_RIGHT (dic) && IC_RIGHT (dic)->key == op->key)
1947 if (POINTER_SET (dic) && IC_RESULT (dic)->key == op->key)
1951 /* now make sure that the right side of dic
1952 is not defined between ic & dic */
1955 iCode *sic = dic->next;
1957 for (; sic != ic; sic = sic->next)
1958 if (IC_RESULT (sic) &&
1959 IC_RESULT (sic)->key == IC_RIGHT (dic)->key)
1968 /*-----------------------------------------------------------------*/
1969 /* packRegsForSupport :- reduce some registers for support calls */
1970 /*-----------------------------------------------------------------*/
1972 packRegsForSupport (iCode * ic, eBBlock * ebp)
1977 /* for the left & right operand :- look to see if the
1978 left was assigned a true symbol in far space in that
1979 case replace them */
1981 if (IS_ITEMP (IC_LEFT (ic)) &&
1982 OP_SYMBOL (IC_LEFT (ic))->liveTo <= ic->seq)
1984 dic = findAssignToSym (IC_LEFT (ic), ic);
1989 /* found it we need to remove it from the
1991 for (sic = dic; sic != ic; sic = sic->next) {
1992 bitVectUnSetBit (sic->rlive, IC_LEFT (ic)->key);
1993 sic->rlive = bitVectSetBit (sic->rlive, IC_RIGHT (dic)->key);
1996 OP_SYMBOL(IC_LEFT (ic))=OP_SYMBOL(IC_RIGHT (dic));
1997 OP_SYMBOL(IC_LEFT(ic))->liveTo = ic->seq;
1998 IC_LEFT (ic)->key = OP_SYMBOL(IC_RIGHT (dic))->key;
1999 remiCodeFromeBBlock (ebp, dic);
2000 bitVectUnSetBit(OP_SYMBOL(IC_RESULT(dic))->defs,dic->key);
2001 hTabDeleteItem (&iCodehTab, dic->key, dic, DELETE_ITEM, NULL);
2005 /* do the same for the right operand */
2008 IS_ITEMP (IC_RIGHT (ic)) &&
2009 OP_SYMBOL (IC_RIGHT (ic))->liveTo <= ic->seq)
2011 iCode *dic = findAssignToSym (IC_RIGHT (ic), ic);
2017 /* if this is a subtraction & the result
2018 is a true symbol in far space then don't pack */
2019 if (ic->op == '-' && IS_TRUE_SYMOP (IC_RESULT (dic)))
2021 sym_link *etype = getSpec (operandType (IC_RESULT (dic)));
2022 if (IN_FARSPACE (SPEC_OCLS (etype)))
2025 /* found it we need to remove it from the
2027 for (sic = dic; sic != ic; sic = sic->next) {
2028 bitVectUnSetBit (sic->rlive, IC_RIGHT (ic)->key);
2029 sic->rlive = bitVectSetBit (sic->rlive, IC_RIGHT (dic)->key);
2032 IC_RIGHT (ic)->operand.symOperand =
2033 IC_RIGHT (dic)->operand.symOperand;
2034 OP_SYMBOL(IC_RIGHT(ic))->liveTo = ic->seq;
2035 IC_RIGHT (ic)->key = IC_RIGHT (dic)->operand.symOperand->key;
2037 remiCodeFromeBBlock (ebp, dic);
2038 bitVectUnSetBit(OP_SYMBOL(IC_RESULT(dic))->defs,dic->key);
2039 hTabDeleteItem (&iCodehTab, dic->key, dic, DELETE_ITEM, NULL);
2046 #define IS_OP_RUONLY(x) (x && IS_SYMOP(x) && OP_SYMBOL(x)->ruonly)
2049 /*-----------------------------------------------------------------*/
2050 /* packRegsForOneuse : - will reduce some registers for single Use */
2051 /*-----------------------------------------------------------------*/
2053 packRegsForOneuse (iCode * ic, operand * op, eBBlock * ebp)
2058 /* if returning a literal then do nothing */
2062 /* only upto 2 bytes since we cannot predict
2063 the usage of b, & acc */
2064 if (getSize (operandType (op)) > (fReturnSizeMCS51 - 2))
2067 if (ic->op != RETURN &&
2069 !POINTER_SET (ic) &&
2073 if (ic->op == SEND && ic->argreg != 1) return NULL;
2075 /* this routine will mark the a symbol as used in one
2076 instruction use only && if the defintion is local
2077 (ie. within the basic block) && has only one definition &&
2078 that definiion is either a return value from a
2079 function or does not contain any variables in
2081 uses = bitVectCopy (OP_USES (op));
2082 bitVectUnSetBit (uses, ic->key); /* take away this iCode */
2083 if (!bitVectIsZero (uses)) /* has other uses */
2086 /* if it has only one defintion */
2087 if (bitVectnBitsOn (OP_DEFS (op)) > 1)
2088 return NULL; /* has more than one definition */
2090 /* get that definition */
2092 hTabItemWithKey (iCodehTab,
2093 bitVectFirstBit (OP_DEFS (op)))))
2096 /* if that only usage is a cast */
2097 if (dic->op == CAST) {
2098 /* to a bigger type */
2099 if (getSize(OP_SYM_TYPE(IC_RESULT(dic))) >
2100 getSize(OP_SYM_TYPE(IC_RIGHT(dic)))) {
2101 /* than we can not, since we cannot predict the usage of b & acc */
2106 /* found the definition now check if it is local */
2107 if (dic->seq < ebp->fSeq ||
2108 dic->seq > ebp->lSeq)
2109 return NULL; /* non-local */
2111 /* now check if it is the return from
2113 if (dic->op == CALL || dic->op == PCALL)
2115 if (ic->op != SEND && ic->op != RETURN &&
2116 !POINTER_SET(ic) && !POINTER_GET(ic))
2118 OP_SYMBOL (op)->ruonly = 1;
2125 /* otherwise check that the definition does
2126 not contain any symbols in far space */
2127 if (isOperandInFarSpace (IC_LEFT (dic)) ||
2128 isOperandInFarSpace (IC_RIGHT (dic)) ||
2129 IS_OP_RUONLY (IC_LEFT (ic)) ||
2130 IS_OP_RUONLY (IC_RIGHT (ic)))
2135 /* if pointer set then make sure the pointer
2137 if (POINTER_SET (dic) &&
2138 !IS_DATA_PTR (aggrToPtr (operandType (IC_RESULT (dic)), FALSE)))
2141 if (POINTER_GET (dic) &&
2142 !IS_DATA_PTR (aggrToPtr (operandType (IC_LEFT (dic)), FALSE)))
2147 /* also make sure the intervenening instructions
2148 don't have any thing in far space */
2149 for (dic = dic->next; dic && dic != ic && sic != ic; dic = dic->next)
2152 /* if there is an intervening function call then no */
2153 if (dic->op == CALL || dic->op == PCALL)
2155 /* if pointer set then make sure the pointer
2157 if (POINTER_SET (dic) &&
2158 !IS_DATA_PTR (aggrToPtr (operandType (IC_RESULT (dic)), FALSE)))
2161 if (POINTER_GET (dic) &&
2162 !IS_DATA_PTR (aggrToPtr (operandType (IC_LEFT (dic)), FALSE)))
2165 /* if address of & the result is remat the okay */
2166 if (dic->op == ADDRESS_OF &&
2167 OP_SYMBOL (IC_RESULT (dic))->remat)
2170 /* if operand has size of three or more & this
2171 operation is a '*','/' or '%' then 'b' may
2173 if ((dic->op == '%' || dic->op == '/' || dic->op == '*') &&
2174 getSize (operandType (op)) >= 3)
2177 /* if left or right or result is in far space */
2178 if (isOperandInFarSpace (IC_LEFT (dic)) ||
2179 isOperandInFarSpace (IC_RIGHT (dic)) ||
2180 isOperandInFarSpace (IC_RESULT (dic)) ||
2181 IS_OP_RUONLY (IC_LEFT (dic)) ||
2182 IS_OP_RUONLY (IC_RIGHT (dic)) ||
2183 IS_OP_RUONLY (IC_RESULT (dic)))
2187 /* if left or right or result is on stack */
2188 if (isOperandOnStack(IC_LEFT(dic)) ||
2189 isOperandOnStack(IC_RIGHT(dic)) ||
2190 isOperandOnStack(IC_RESULT(dic))) {
2195 OP_SYMBOL (op)->ruonly = 1;
2200 /*-----------------------------------------------------------------*/
2201 /* isBitwiseOptimizable - requirements of JEAN LOUIS VERN */
2202 /*-----------------------------------------------------------------*/
2204 isBitwiseOptimizable (iCode * ic)
2206 sym_link *ltype = getSpec (operandType (IC_LEFT (ic)));
2207 sym_link *rtype = getSpec (operandType (IC_RIGHT (ic)));
2209 /* bitwise operations are considered optimizable
2210 under the following conditions (Jean-Louis VERN)
2222 if (IS_LITERAL(rtype) ||
2223 (IS_BITVAR (ltype) && IN_BITSPACE (SPEC_OCLS (ltype))))
2229 /*-----------------------------------------------------------------*/
2230 /* packRegsForAccUse - pack registers for acc use */
2231 /*-----------------------------------------------------------------*/
2233 packRegsForAccUse (iCode * ic)
2237 /* if this is an aggregate, e.g. a one byte char array */
2238 if (IS_AGGREGATE(operandType(IC_RESULT(ic)))) {
2242 /* if we are calling a reentrant function that has stack parameters */
2243 if (ic->op == CALL &&
2244 IFFUNC_ISREENT(operandType(IC_LEFT(ic))) &&
2245 FUNC_HASSTACKPARM(operandType(IC_LEFT(ic))))
2248 if (ic->op == PCALL &&
2249 IFFUNC_ISREENT(operandType(IC_LEFT(ic))->next) &&
2250 FUNC_HASSTACKPARM(operandType(IC_LEFT(ic))->next))
2253 /* if + or - then it has to be one byte result */
2254 if ((ic->op == '+' || ic->op == '-')
2255 && getSize (operandType (IC_RESULT (ic))) > 1)
2258 /* if shift operation make sure right side is not a literal */
2259 if (ic->op == RIGHT_OP &&
2260 (isOperandLiteral (IC_RIGHT (ic)) ||
2261 getSize (operandType (IC_RESULT (ic))) > 1))
2264 if (ic->op == LEFT_OP &&
2265 (isOperandLiteral (IC_RIGHT (ic)) ||
2266 getSize (operandType (IC_RESULT (ic))) > 1))
2269 if (IS_BITWISE_OP (ic) &&
2270 getSize (operandType (IC_RESULT (ic))) > 1)
2274 /* has only one definition */
2275 if (bitVectnBitsOn (OP_DEFS (IC_RESULT (ic))) > 1)
2278 /* has only one use */
2279 if (bitVectnBitsOn (OP_USES (IC_RESULT (ic))) > 1)
2282 /* and the usage immediately follows this iCode */
2283 if (!(uic = hTabItemWithKey (iCodehTab,
2284 bitVectFirstBit (OP_USES (IC_RESULT (ic))))))
2287 if (ic->next != uic)
2290 /* if it is a conditional branch then we definitely can */
2294 if (uic->op == JUMPTABLE)
2297 /* if the usage is not is an assignment
2298 or an arithmetic / bitwise / shift operation then not */
2299 if (POINTER_SET (uic) &&
2300 getSize (aggrToPtr (operandType (IC_RESULT (uic)), FALSE)) > 1)
2303 if (uic->op != '=' &&
2304 !IS_ARITHMETIC_OP (uic) &&
2305 !IS_BITWISE_OP (uic) &&
2306 uic->op != LEFT_OP &&
2307 uic->op != RIGHT_OP)
2310 /* if used in ^ operation then make sure right is not a
2312 if (uic->op == '^' && isOperandLiteral (IC_RIGHT (uic)))
2315 /* if shift operation make sure right side is not a literal */
2316 if (uic->op == RIGHT_OP &&
2317 (isOperandLiteral (IC_RIGHT (uic)) ||
2318 getSize (operandType (IC_RESULT (uic))) > 1))
2321 if (uic->op == LEFT_OP &&
2322 (isOperandLiteral (IC_RIGHT (uic)) ||
2323 getSize (operandType (IC_RESULT (uic))) > 1))
2326 /* make sure that the result of this icode is not on the
2327 stack, since acc is used to compute stack offset */
2329 if (IS_TRUE_SYMOP (IC_RESULT (uic)) &&
2330 OP_SYMBOL (IC_RESULT (uic))->onStack)
2333 if (isOperandOnStack(IC_RESULT(uic)))
2337 /* if either one of them in far space then we cannot */
2338 if ((IS_TRUE_SYMOP (IC_LEFT (uic)) &&
2339 isOperandInFarSpace (IC_LEFT (uic))) ||
2340 (IS_TRUE_SYMOP (IC_RIGHT (uic)) &&
2341 isOperandInFarSpace (IC_RIGHT (uic))))
2344 /* if the usage has only one operand then we can */
2345 if (IC_LEFT (uic) == NULL ||
2346 IC_RIGHT (uic) == NULL)
2349 /* make sure this is on the left side if not
2350 a '+' since '+' is commutative */
2351 if (ic->op != '+' &&
2352 IC_LEFT (uic)->key != IC_RESULT (ic)->key)
2356 // this is too dangerous and need further restrictions
2359 /* if one of them is a literal then we can */
2360 if ((IC_LEFT (uic) && IS_OP_LITERAL (IC_LEFT (uic))) ||
2361 (IC_RIGHT (uic) && IS_OP_LITERAL (IC_RIGHT (uic))))
2363 OP_SYMBOL (IC_RESULT (ic))->accuse = 1;
2368 /* if the other one is not on stack then we can */
2369 if (IC_LEFT (uic)->key == IC_RESULT (ic)->key &&
2370 (IS_ITEMP (IC_RIGHT (uic)) ||
2371 (IS_TRUE_SYMOP (IC_RIGHT (uic)) &&
2372 !OP_SYMBOL (IC_RIGHT (uic))->onStack)))
2375 if (IC_RIGHT (uic)->key == IC_RESULT (ic)->key &&
2376 (IS_ITEMP (IC_LEFT (uic)) ||
2377 (IS_TRUE_SYMOP (IC_LEFT (uic)) &&
2378 !OP_SYMBOL (IC_LEFT (uic))->onStack)))
2384 OP_SYMBOL (IC_RESULT (ic))->accuse = 1;
2389 /*-----------------------------------------------------------------*/
2390 /* packForPush - hueristics to reduce iCode for pushing */
2391 /*-----------------------------------------------------------------*/
2393 packForPush (iCode * ic, eBBlock * ebp)
2398 if (ic->op != IPUSH || !IS_ITEMP (IC_LEFT (ic)))
2401 /* must have only definition & one usage */
2402 if (bitVectnBitsOn (OP_DEFS (IC_LEFT (ic))) != 1 ||
2403 bitVectnBitsOn (OP_USES (IC_LEFT (ic))) != 1)
2406 /* find the definition */
2407 if (!(dic = hTabItemWithKey (iCodehTab,
2408 bitVectFirstBit (OP_DEFS (IC_LEFT (ic))))))
2411 if (dic->op != '=' || POINTER_SET (dic))
2414 /* make sure the right side does not have any definitions
2416 dbv = OP_DEFS(IC_RIGHT(dic));
2417 for (lic = ic; lic && lic != dic ; lic = lic->prev) {
2418 if (bitVectBitValue(dbv,lic->key))
2421 /* make sure they have the same type */
2423 sym_link *itype=operandType(IC_LEFT(ic));
2424 sym_link *ditype=operandType(IC_RIGHT(dic));
2426 if (SPEC_USIGN(itype)!=SPEC_USIGN(ditype) ||
2427 SPEC_LONG(itype)!=SPEC_LONG(ditype))
2430 /* extend the live range of replaced operand if needed */
2431 if (OP_SYMBOL(IC_RIGHT(dic))->liveTo < ic->seq) {
2432 OP_SYMBOL(IC_RIGHT(dic))->liveTo = ic->seq;
2434 /* we now we know that it has one & only one def & use
2435 and the that the definition is an assignment */
2436 IC_LEFT (ic) = IC_RIGHT (dic);
2438 remiCodeFromeBBlock (ebp, dic);
2439 bitVectUnSetBit(OP_SYMBOL(IC_RESULT(dic))->defs,dic->key);
2440 hTabDeleteItem (&iCodehTab, dic->key, dic, DELETE_ITEM, NULL);
2443 /*-----------------------------------------------------------------*/
2444 /* packRegisters - does some transformations to reduce register */
2446 /*-----------------------------------------------------------------*/
2448 packRegisters (eBBlock * ebp)
2458 /* look for assignments of the form */
2459 /* iTempNN = TRueSym (someoperation) SomeOperand */
2461 /* TrueSym := iTempNN:1 */
2462 for (ic = ebp->sch; ic; ic = ic->next)
2464 /* find assignment of the form TrueSym := iTempNN:1 */
2465 if (ic->op == '=' && !POINTER_SET (ic))
2466 change += packRegsForAssign (ic, ebp);
2473 for (ic = ebp->sch; ic; ic = ic->next)
2475 /* if this is an itemp & result of an address of a true sym
2476 then mark this as rematerialisable */
2477 if (ic->op == ADDRESS_OF &&
2478 IS_ITEMP (IC_RESULT (ic)) &&
2479 IS_TRUE_SYMOP (IC_LEFT (ic)) &&
2480 bitVectnBitsOn (OP_DEFS (IC_RESULT (ic))) == 1 &&
2481 !OP_SYMBOL (IC_LEFT (ic))->onStack)
2484 OP_SYMBOL (IC_RESULT (ic))->remat = 1;
2485 OP_SYMBOL (IC_RESULT (ic))->rematiCode = ic;
2486 OP_SYMBOL (IC_RESULT (ic))->usl.spillLoc = NULL;
2490 /* if straight assignment then carry remat flag if
2491 this is the only definition */
2492 if (ic->op == '=' &&
2493 !POINTER_SET (ic) &&
2494 IS_SYMOP (IC_RIGHT (ic)) &&
2495 OP_SYMBOL (IC_RIGHT (ic))->remat &&
2496 !IS_CAST_ICODE(OP_SYMBOL (IC_RIGHT (ic))->rematiCode) &&
2497 bitVectnBitsOn (OP_SYMBOL (IC_RESULT (ic))->defs) <= 1)
2500 OP_SYMBOL (IC_RESULT (ic))->remat =
2501 OP_SYMBOL (IC_RIGHT (ic))->remat;
2502 OP_SYMBOL (IC_RESULT (ic))->rematiCode =
2503 OP_SYMBOL (IC_RIGHT (ic))->rematiCode;
2506 /* if cast to a generic pointer & the pointer being
2507 cast is remat, then we can remat this cast as well */
2508 if (ic->op == CAST &&
2509 IS_SYMOP(IC_RIGHT(ic)) &&
2510 OP_SYMBOL(IC_RIGHT(ic))->remat ) {
2511 sym_link *to_type = operandType(IC_LEFT(ic));
2512 sym_link *from_type = operandType(IC_RIGHT(ic));
2513 if (IS_GENPTR(to_type) && IS_PTR(from_type)) {
2514 OP_SYMBOL (IC_RESULT (ic))->remat = 1;
2515 OP_SYMBOL (IC_RESULT (ic))->rematiCode = ic;
2516 OP_SYMBOL (IC_RESULT (ic))->usl.spillLoc = NULL;
2520 /* if this is a +/- operation with a rematerizable
2521 then mark this as rematerializable as well */
2522 if ((ic->op == '+' || ic->op == '-') &&
2523 (IS_SYMOP (IC_LEFT (ic)) &&
2524 IS_ITEMP (IC_RESULT (ic)) &&
2525 IS_OP_LITERAL (IC_RIGHT (ic))) &&
2526 OP_SYMBOL (IC_LEFT (ic))->remat &&
2527 (!IS_SYMOP (IC_RIGHT (ic)) || !IS_CAST_ICODE(OP_SYMBOL (IC_RIGHT (ic))->rematiCode)) &&
2528 bitVectnBitsOn (OP_DEFS (IC_RESULT (ic))) == 1)
2530 OP_SYMBOL (IC_RESULT (ic))->remat = 1;
2531 OP_SYMBOL (IC_RESULT (ic))->rematiCode = ic;
2532 OP_SYMBOL (IC_RESULT (ic))->usl.spillLoc = NULL;
2535 /* mark the pointer usages */
2536 if (POINTER_SET (ic))
2537 OP_SYMBOL (IC_RESULT (ic))->uptr = 1;
2539 if (POINTER_GET (ic))
2540 OP_SYMBOL (IC_LEFT (ic))->uptr = 1;
2544 /* if we are using a symbol on the stack
2545 then we should say mcs51_ptrRegReq */
2546 if (ic->op == IFX && IS_SYMOP (IC_COND (ic)))
2547 mcs51_ptrRegReq += ((OP_SYMBOL (IC_COND (ic))->onStack ||
2548 OP_SYMBOL (IC_COND (ic))->iaccess) ? 1 : 0);
2549 else if (ic->op == JUMPTABLE && IS_SYMOP (IC_JTCOND (ic)))
2550 mcs51_ptrRegReq += ((OP_SYMBOL (IC_JTCOND (ic))->onStack ||
2551 OP_SYMBOL (IC_JTCOND (ic))->iaccess) ? 1 : 0);
2554 if (IS_SYMOP (IC_LEFT (ic)))
2555 mcs51_ptrRegReq += ((OP_SYMBOL (IC_LEFT (ic))->onStack ||
2556 OP_SYMBOL (IC_LEFT (ic))->iaccess) ? 1 : 0);
2557 if (IS_SYMOP (IC_RIGHT (ic)))
2558 mcs51_ptrRegReq += ((OP_SYMBOL (IC_RIGHT (ic))->onStack ||
2559 OP_SYMBOL (IC_RIGHT (ic))->iaccess) ? 1 : 0);
2560 if (IS_SYMOP (IC_RESULT (ic)))
2561 mcs51_ptrRegReq += ((OP_SYMBOL (IC_RESULT (ic))->onStack ||
2562 OP_SYMBOL (IC_RESULT (ic))->iaccess) ? 1 : 0);
2566 /* if the condition of an if instruction
2567 is defined in the previous instruction and
2568 this is the only usage then
2569 mark the itemp as a conditional */
2570 if ((IS_CONDITIONAL (ic) ||
2571 (IS_BITWISE_OP(ic) && isBitwiseOptimizable (ic))) &&
2572 ic->next && ic->next->op == IFX &&
2573 bitVectnBitsOn (OP_USES(IC_RESULT(ic)))==1 &&
2574 isOperandEqual (IC_RESULT (ic), IC_COND (ic->next)) &&
2575 OP_SYMBOL (IC_RESULT (ic))->liveTo <= ic->next->seq)
2577 OP_SYMBOL (IC_RESULT (ic))->regType = REG_CND;
2581 /* reduce for support function calls */
2582 if (ic->supportRtn || ic->op == '+' || ic->op == '-')
2583 packRegsForSupport (ic, ebp);
2585 /* some cases the redundant moves can
2586 can be eliminated for return statements */
2587 if ((ic->op == RETURN || (ic->op == SEND && ic->argreg == 1)) &&
2588 !isOperandInFarSpace (IC_LEFT (ic)) &&
2589 options.model == MODEL_SMALL) {
2590 if (0 && options.stackAuto) {
2591 /* we should check here if acc will be clobbered for stack
2592 offset calculations */
2594 packRegsForOneuse (ic, IC_LEFT (ic), ebp);
2598 /* if pointer set & left has a size more than
2599 one and right is not in far space */
2600 if (POINTER_SET (ic) &&
2601 !isOperandInFarSpace (IC_RIGHT (ic)) &&
2602 !OP_SYMBOL (IC_RESULT (ic))->remat &&
2603 !IS_OP_RUONLY (IC_RIGHT (ic)) &&
2604 getSize (aggrToPtr (operandType (IC_RESULT (ic)), FALSE)) > 1)
2606 packRegsForOneuse (ic, IC_RESULT (ic), ebp);
2608 /* if pointer get */
2609 if (POINTER_GET (ic) &&
2610 !isOperandInFarSpace (IC_RESULT (ic)) &&
2611 !OP_SYMBOL (IC_LEFT (ic))->remat &&
2612 !IS_OP_RUONLY (IC_RESULT (ic)) &&
2613 getSize (aggrToPtr (operandType (IC_LEFT (ic)), FALSE)) > 1)
2615 packRegsForOneuse (ic, IC_LEFT (ic), ebp);
2618 /* if this is cast for intergral promotion then
2619 check if only use of the definition of the
2620 operand being casted/ if yes then replace
2621 the result of that arithmetic operation with
2622 this result and get rid of the cast */
2625 sym_link *fromType = operandType (IC_RIGHT (ic));
2626 sym_link *toType = operandType (IC_LEFT (ic));
2628 if (IS_INTEGRAL (fromType) && IS_INTEGRAL (toType) &&
2629 getSize (fromType) != getSize (toType) &&
2630 SPEC_USIGN (fromType) == SPEC_USIGN (toType))
2633 iCode *dic = packRegsForOneuse (ic, IC_RIGHT (ic), ebp);
2636 if (IS_ARITHMETIC_OP (dic))
2638 bitVectUnSetBit(OP_SYMBOL(IC_RESULT(dic))->defs,dic->key);
2639 IC_RESULT (dic) = IC_RESULT (ic);
2640 remiCodeFromeBBlock (ebp, ic);
2641 bitVectUnSetBit(OP_SYMBOL(IC_RESULT(ic))->defs,ic->key);
2642 hTabDeleteItem (&iCodehTab, ic->key, ic, DELETE_ITEM, NULL);
2643 OP_DEFS (IC_RESULT (dic)) = bitVectSetBit (OP_DEFS (IC_RESULT (dic)), dic->key);
2647 OP_SYMBOL (IC_RIGHT (ic))->ruonly = 0;
2653 /* if the type from and type to are the same
2654 then if this is the only use then packit */
2655 if (compareType (operandType (IC_RIGHT (ic)),
2656 operandType (IC_LEFT (ic))) == 1)
2658 iCode *dic = packRegsForOneuse (ic, IC_RIGHT (ic), ebp);
2661 bitVectUnSetBit(OP_SYMBOL(IC_RESULT(dic))->defs,dic->key);
2662 IC_RESULT (dic) = IC_RESULT (ic);
2663 remiCodeFromeBBlock (ebp, ic);
2664 bitVectUnSetBit(OP_SYMBOL(IC_RESULT(ic))->defs,ic->key);
2665 hTabDeleteItem (&iCodehTab, ic->key, ic, DELETE_ITEM, NULL);
2666 OP_DEFS (IC_RESULT (dic)) = bitVectSetBit (OP_DEFS (IC_RESULT (dic)), dic->key);
2674 iTempNN := (some variable in farspace) V1
2679 if (ic->op == IPUSH)
2681 packForPush (ic, ebp);
2685 /* pack registers for accumulator use, when the
2686 result of an arithmetic or bit wise operation
2687 has only one use, that use is immediately following
2688 the defintion and the using iCode has only one
2689 operand or has two operands but one is literal &
2690 the result of that operation is not on stack then
2691 we can leave the result of this operation in acc:b
2693 if ((IS_ARITHMETIC_OP (ic)
2694 || IS_CONDITIONAL(ic)
2695 || IS_BITWISE_OP (ic)
2696 || ic->op == LEFT_OP || ic->op == RIGHT_OP || ic->op == CALL
2697 || (ic->op == ADDRESS_OF && isOperandOnStack (IC_LEFT (ic)))
2699 IS_ITEMP (IC_RESULT (ic)) &&
2700 getSize (operandType (IC_RESULT (ic))) <= 2)
2702 packRegsForAccUse (ic);
2706 /*-----------------------------------------------------------------*/
2707 /* assignRegisters - assigns registers to each live range as need */
2708 /*-----------------------------------------------------------------*/
2710 mcs51_assignRegisters (eBBlock ** ebbs, int count)
2715 setToNull ((void *) &_G.funcrUsed);
2716 setToNull ((void *) &_G.totRegAssigned);
2717 mcs51_ptrRegReq = _G.stackExtend = _G.dataExtend = 0;
2720 /* change assignments this will remove some
2721 live ranges reducing some register pressure */
2722 for (i = 0; i < count; i++)
2723 packRegisters (ebbs[i]);
2725 if (options.dump_pack)
2726 dumpEbbsToFileExt (DUMP_PACK, ebbs, count);
2728 /* first determine for each live range the number of
2729 registers & the type of registers required for each */
2732 /* and serially allocate registers */
2733 serialRegAssign (ebbs, count);
2738 /* if stack was extended then tell the user */
2741 /* werror(W_TOOMANY_SPILS,"stack", */
2742 /* _G.stackExtend,currFunc->name,""); */
2748 /* werror(W_TOOMANY_SPILS,"data space", */
2749 /* _G.dataExtend,currFunc->name,""); */
2753 /* after that create the register mask
2754 for each of the instruction */
2755 createRegMask (ebbs, count);
2757 /* redo that offsets for stacked automatic variables */
2758 redoStackOffsets ();
2760 if (options.dump_rassgn)
2762 dumpEbbsToFileExt (DUMP_RASSGN, ebbs, count);
2763 dumpLiveRanges (DUMP_LRANGE, liveRanges);
2766 /* do the overlaysegment stuff SDCCmem.c */
2767 doOverlays (ebbs, count);
2769 /* now get back the chain */
2770 ic = iCodeLabelOptimize (iCodeFromeBBlock (ebbs, count));
2774 /* free up any _G.stackSpil locations allocated */
2775 applyToSet (_G.stackSpil, deallocStackSpil);
2777 setToNull ((void **) &_G.stackSpil);
2778 setToNull ((void **) &_G.spiltSet);
2779 /* mark all registers as free */