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]) {
1245 fprintf (stderr, "%d reg(s) lost in %s:%d\n",
1246 j, __FILE__,__LINE__);
1252 /* if it shares registers with operands make sure
1253 that they are in the same position */
1254 if (IC_LEFT (ic) && IS_SYMOP (IC_LEFT (ic)) &&
1255 OP_SYMBOL (IC_LEFT (ic))->nRegs && ic->op != '=') {
1256 positionRegs (OP_SYMBOL (IC_RESULT (ic)),
1257 OP_SYMBOL (IC_LEFT (ic)));
1259 /* do the same for the right operand */
1260 if (IC_RIGHT (ic) && IS_SYMOP (IC_RIGHT (ic)) &&
1261 OP_SYMBOL (IC_RIGHT (ic))->nRegs) {
1262 positionRegs (OP_SYMBOL (IC_RESULT (ic)),
1263 OP_SYMBOL (IC_RIGHT (ic)));
1276 /*-----------------------------------------------------------------*/
1277 /* fillGaps - Try to fill in the Gaps left by Pass1 */
1278 /*-----------------------------------------------------------------*/
1279 static void fillGaps()
1284 if (getenv("DISABLE_FILL_GAPS")) return;
1286 /* look for livernages that was spilt by the allocator */
1287 for (sym = hTabFirstItem(liveRanges,&key) ; sym ;
1288 sym = hTabNextItem(liveRanges,&key)) {
1293 if (!sym->spillA || !sym->clashes || sym->remat) continue ;
1295 /* find the liveRanges this one clashes with, that are
1296 still assigned to registers & mark the registers as used*/
1297 for ( i = 0 ; i < sym->clashes->size ; i ++) {
1301 if (bitVectBitValue(sym->clashes,i) == 0 || /* those that clash with this */
1302 bitVectBitValue(_G.totRegAssigned,i) == 0) /* and are still assigned to registers */
1305 assert (clr = hTabItemWithKey(liveRanges,i));
1307 /* mark these registers as used */
1308 for (k = 0 ; k < clr->nRegs ; k++ )
1309 useReg(clr->regs[k]);
1312 if (willCauseSpill(sym->nRegs,sym->regType)) {
1313 /* NOPE :( clear all registers & and continue */
1318 /* THERE IS HOPE !!!! */
1319 for (i=0; i < sym->nRegs ; i++ ) {
1320 if (sym->regType == REG_PTR)
1321 sym->regs[i] = getRegPtrNoSpil ();
1323 sym->regs[i] = getRegGprNoSpil ();
1326 /* for all its definitions check if the registers
1327 allocated needs positioning NOTE: we can position
1328 only ONCE if more than One positioning required
1331 for (i = 0 ; i < sym->defs->size ; i++ ) {
1332 if (bitVectBitValue(sym->defs,i)) {
1334 if (!(ic = hTabItemWithKey(iCodehTab,i))) continue ;
1335 if (SKIP_IC(ic)) continue;
1336 assert(isSymbolEqual(sym,OP_SYMBOL(IC_RESULT(ic)))); /* just making sure */
1337 /* if left is assigned to registers */
1338 if (IS_SYMOP(IC_LEFT(ic)) &&
1339 bitVectBitValue(_G.totRegAssigned,OP_SYMBOL(IC_LEFT(ic))->key)) {
1340 pdone += positionRegs(sym,OP_SYMBOL(IC_LEFT(ic)));
1342 if (IS_SYMOP(IC_RIGHT(ic)) &&
1343 bitVectBitValue(_G.totRegAssigned,OP_SYMBOL(IC_RIGHT(ic))->key)) {
1344 pdone += positionRegs(sym,OP_SYMBOL(IC_RIGHT(ic)));
1346 if (pdone > 1) break;
1349 for (i = 0 ; i < sym->uses->size ; i++ ) {
1350 if (bitVectBitValue(sym->uses,i)) {
1352 if (!(ic = hTabItemWithKey(iCodehTab,i))) continue ;
1353 if (SKIP_IC(ic)) continue;
1354 if (!IS_ASSIGN_ICODE(ic)) continue ;
1356 /* if result is assigned to registers */
1357 if (IS_SYMOP(IC_RESULT(ic)) &&
1358 bitVectBitValue(_G.totRegAssigned,OP_SYMBOL(IC_RESULT(ic))->key)) {
1359 pdone += positionRegs(sym,OP_SYMBOL(IC_RESULT(ic)));
1361 if (pdone > 1) break;
1364 /* had to position more than once GIVE UP */
1366 /* UNDO all the changes we made to try this */
1368 for (i=0; i < sym->nRegs ; i++ ) {
1369 sym->regs[i] = NULL;
1372 D(printf ("Fill Gap gave up due to positioning for %s in function %s\n",sym->name, currFunc ? currFunc->name : "UNKNOWN"));
1375 D(printf ("FILLED GAP for %s in function %s\n",sym->name, currFunc ? currFunc->name : "UNKNOWN"));
1376 _G.totRegAssigned = bitVectSetBit(_G.totRegAssigned,sym->key);
1377 sym->isspilt = sym->spillA = 0 ;
1378 sym->usl.spillLoc->allocreq--;
1383 /*-----------------------------------------------------------------*/
1384 /* rUmaskForOp :- returns register mask for an operand */
1385 /*-----------------------------------------------------------------*/
1387 mcs51_rUmaskForOp (operand * op)
1393 /* only temporaries are assigned registers */
1397 sym = OP_SYMBOL (op);
1399 /* if spilt or no registers assigned to it
1401 if (sym->isspilt || !sym->nRegs)
1404 rumask = newBitVect (mcs51_nRegs);
1406 for (j = 0; j < sym->nRegs; j++)
1408 rumask = bitVectSetBit (rumask,
1409 sym->regs[j]->rIdx);
1415 /*-----------------------------------------------------------------*/
1416 /* regsUsedIniCode :- returns bit vector of registers used in iCode */
1417 /*-----------------------------------------------------------------*/
1419 regsUsedIniCode (iCode * ic)
1421 bitVect *rmask = newBitVect (mcs51_nRegs);
1423 /* do the special cases first */
1426 rmask = bitVectUnion (rmask,
1427 mcs51_rUmaskForOp (IC_COND (ic)));
1431 /* for the jumptable */
1432 if (ic->op == JUMPTABLE)
1434 rmask = bitVectUnion (rmask,
1435 mcs51_rUmaskForOp (IC_JTCOND (ic)));
1440 /* of all other cases */
1442 rmask = bitVectUnion (rmask,
1443 mcs51_rUmaskForOp (IC_LEFT (ic)));
1447 rmask = bitVectUnion (rmask,
1448 mcs51_rUmaskForOp (IC_RIGHT (ic)));
1451 rmask = bitVectUnion (rmask,
1452 mcs51_rUmaskForOp (IC_RESULT (ic)));
1458 /*-----------------------------------------------------------------*/
1459 /* createRegMask - for each instruction will determine the regsUsed */
1460 /*-----------------------------------------------------------------*/
1462 createRegMask (eBBlock ** ebbs, int count)
1466 /* for all blocks */
1467 for (i = 0; i < count; i++)
1471 if (ebbs[i]->noPath &&
1472 (ebbs[i]->entryLabel != entryLabel &&
1473 ebbs[i]->entryLabel != returnLabel))
1476 /* for all instructions */
1477 for (ic = ebbs[i]->sch; ic; ic = ic->next)
1482 if (SKIP_IC2 (ic) || !ic->rlive)
1485 /* first mark the registers used in this
1487 ic->rUsed = regsUsedIniCode (ic);
1488 _G.funcrUsed = bitVectUnion (_G.funcrUsed, ic->rUsed);
1490 /* now create the register mask for those
1491 registers that are in use : this is a
1492 super set of ic->rUsed */
1493 ic->rMask = newBitVect (mcs51_nRegs + 1);
1495 /* for all live Ranges alive at this point */
1496 for (j = 1; j < ic->rlive->size; j++)
1501 /* if not alive then continue */
1502 if (!bitVectBitValue (ic->rlive, j))
1505 /* find the live range we are interested in */
1506 if (!(sym = hTabItemWithKey (liveRanges, j)))
1508 werror (E_INTERNAL_ERROR, __FILE__, __LINE__,
1509 "createRegMask cannot find live range");
1513 /* if no register assigned to it */
1514 if (!sym->nRegs || sym->isspilt)
1517 /* for all the registers allocated to it */
1518 for (k = 0; k < sym->nRegs; k++)
1521 bitVectSetBit (ic->rMask, sym->regs[k]->rIdx);
1527 /*-----------------------------------------------------------------*/
1528 /* rematStr - returns the rematerialized string for a remat var */
1529 /*-----------------------------------------------------------------*/
1531 rematStr (symbol * sym)
1534 iCode *ic = sym->rematiCode;
1539 /* if plus or minus print the right hand side */
1540 if (ic->op == '+' || ic->op == '-')
1542 sprintf (s, "0x%04x %c ", (int) operandLitValue (IC_RIGHT (ic)),
1545 ic = OP_SYMBOL (IC_LEFT (ic))->rematiCode;
1549 /* cast then continue */
1550 if (IS_CAST_ICODE(ic)) {
1551 ic = OP_SYMBOL (IC_RIGHT (ic))->rematiCode;
1554 /* we reached the end */
1555 sprintf (s, "%s", OP_SYMBOL (IC_LEFT (ic))->rname);
1562 /*-----------------------------------------------------------------*/
1563 /* regTypeNum - computes the type & number of registers required */
1564 /*-----------------------------------------------------------------*/
1566 regTypeNum (eBBlock *ebbs)
1572 /* for each live range do */
1573 for (sym = hTabFirstItem (liveRanges, &k); sym;
1574 sym = hTabNextItem (liveRanges, &k))
1577 /* if used zero times then no registers needed */
1578 if ((sym->liveTo - sym->liveFrom) == 0)
1582 /* if the live range is a temporary */
1586 /* if the type is marked as a conditional */
1587 if (sym->regType == REG_CND)
1590 /* if used in return only then we don't
1592 if (sym->ruonly || sym->accuse)
1594 if (IS_AGGREGATE (sym->type) || sym->isptr)
1595 sym->type = aggrToPtr (sym->type, FALSE);
1599 /* if the symbol has only one definition &
1600 that definition is a get_pointer */
1601 if (bitVectnBitsOn (sym->defs) == 1 &&
1602 (ic = hTabItemWithKey (iCodehTab,
1603 bitVectFirstBit (sym->defs))) &&
1606 !IS_BITVAR (sym->etype))
1610 /* and that pointer is remat in data space */
1611 if (OP_SYMBOL (IC_LEFT (ic))->remat &&
1612 !IS_CAST_ICODE(OP_SYMBOL (IC_LEFT (ic))->rematiCode) &&
1613 DCL_TYPE (aggrToPtr (operandType(IC_LEFT(ic)), FALSE)) == POINTER)
1615 /* create a psuedo symbol & force a spil */
1616 symbol *psym = newSymbol (rematStr (OP_SYMBOL (IC_LEFT (ic))), 1);
1617 psym->type = sym->type;
1618 psym->etype = sym->etype;
1619 strcpy (psym->rname, psym->name);
1621 sym->usl.spillLoc = psym;
1622 #if 0 // an alternative fix for bug #480076
1623 /* now this is a useless assignment to itself */
1624 remiCodeFromeBBlock (ebbs, ic);
1626 /* now this really is an assignment to itself, make it so;
1627 it will be optimized out later */
1629 IC_RIGHT(ic)=IC_RESULT(ic);
1635 /* if in data space or idata space then try to
1636 allocate pointer register */
1640 /* if not then we require registers */
1641 sym->nRegs = ((IS_AGGREGATE (sym->type) || sym->isptr) ?
1642 getSize (sym->type = aggrToPtr (sym->type, FALSE)) :
1643 getSize (sym->type));
1647 fprintf (stderr, "allocated more than 4 or 0 registers for type ");
1648 printTypeChain (sym->type, stderr);
1649 fprintf (stderr, "\n");
1652 /* determine the type of register required */
1653 if (sym->nRegs == 1 &&
1654 IS_PTR (sym->type) &&
1656 sym->regType = REG_PTR;
1658 sym->regType = REG_GPR;
1662 /* for the first run we don't provide */
1663 /* registers for true symbols we will */
1664 /* see how things go */
1670 /*-----------------------------------------------------------------*/
1671 /* freeAllRegs - mark all registers as free */
1672 /*-----------------------------------------------------------------*/
1678 for (i = 0; i < mcs51_nRegs; i++)
1679 regs8051[i].isFree = 1;
1682 /*-----------------------------------------------------------------*/
1683 /* deallocStackSpil - this will set the stack pointer back */
1684 /*-----------------------------------------------------------------*/
1686 DEFSETFUNC (deallocStackSpil)
1694 /*-----------------------------------------------------------------*/
1695 /* farSpacePackable - returns the packable icode for far variables */
1696 /*-----------------------------------------------------------------*/
1698 farSpacePackable (iCode * ic)
1702 /* go thru till we find a definition for the
1703 symbol on the right */
1704 for (dic = ic->prev; dic; dic = dic->prev)
1706 /* if the definition is a call then no */
1707 if ((dic->op == CALL || dic->op == PCALL) &&
1708 IC_RESULT (dic)->key == IC_RIGHT (ic)->key)
1713 /* if shift by unknown amount then not */
1714 if ((dic->op == LEFT_OP || dic->op == RIGHT_OP) &&
1715 IC_RESULT (dic)->key == IC_RIGHT (ic)->key)
1718 /* if pointer get and size > 1 */
1719 if (POINTER_GET (dic) &&
1720 getSize (aggrToPtr (operandType (IC_LEFT (dic)), FALSE)) > 1)
1723 if (POINTER_SET (dic) &&
1724 getSize (aggrToPtr (operandType (IC_RESULT (dic)), FALSE)) > 1)
1727 /* if any three is a true symbol in far space */
1728 if (IC_RESULT (dic) &&
1729 IS_TRUE_SYMOP (IC_RESULT (dic)) &&
1730 isOperandInFarSpace (IC_RESULT (dic)))
1733 if (IC_RIGHT (dic) &&
1734 IS_TRUE_SYMOP (IC_RIGHT (dic)) &&
1735 isOperandInFarSpace (IC_RIGHT (dic)) &&
1736 !isOperandEqual (IC_RIGHT (dic), IC_RESULT (ic)))
1739 if (IC_LEFT (dic) &&
1740 IS_TRUE_SYMOP (IC_LEFT (dic)) &&
1741 isOperandInFarSpace (IC_LEFT (dic)) &&
1742 !isOperandEqual (IC_LEFT (dic), IC_RESULT (ic)))
1745 if (isOperandEqual (IC_RIGHT (ic), IC_RESULT (dic)))
1747 if ((dic->op == LEFT_OP ||
1748 dic->op == RIGHT_OP ||
1750 IS_OP_LITERAL (IC_RIGHT (dic)))
1760 /*-----------------------------------------------------------------*/
1761 /* packRegsForAssign - register reduction for assignment */
1762 /*-----------------------------------------------------------------*/
1764 packRegsForAssign (iCode * ic, eBBlock * ebp)
1767 //sym_link *etype = operandType (IC_RIGHT (ic));
1769 if (!IS_ITEMP (IC_RIGHT (ic)) ||
1770 OP_SYMBOL (IC_RIGHT (ic))->isind ||
1771 OP_LIVETO (IC_RIGHT (ic)) > ic->seq
1772 /* why? || IS_BITFIELD (etype) */ )
1777 /* if the true symbol is defined in far space or on stack
1778 then we should not since this will increase register pressure */
1779 if (isOperandInFarSpace(IC_RESULT(ic)) && !farSpacePackable(ic)) {
1783 /* find the definition of iTempNN scanning backwards if we find a
1784 a use of the true symbol in before we find the definition then
1786 for (dic = ic->prev; dic; dic = dic->prev)
1788 /* if there is a function call then don't pack it */
1789 if ((dic->op == CALL || dic->op == PCALL))
1798 if (IS_TRUE_SYMOP (IC_RESULT (dic)) &&
1799 IS_OP_VOLATILE (IC_RESULT (dic)))
1805 if (IS_SYMOP (IC_RESULT (dic)) &&
1806 IC_RESULT (dic)->key == IC_RIGHT (ic)->key)
1808 if (POINTER_SET (dic))
1814 if (IS_SYMOP (IC_RIGHT (dic)) &&
1815 (IC_RIGHT (dic)->key == IC_RESULT (ic)->key ||
1816 IC_RIGHT (dic)->key == IC_RIGHT (ic)->key))
1822 if (IS_SYMOP (IC_LEFT (dic)) &&
1823 (IC_LEFT (dic)->key == IC_RESULT (ic)->key ||
1824 IC_LEFT (dic)->key == IC_RIGHT (ic)->key))
1830 if (POINTER_SET (dic) &&
1831 IC_RESULT (dic)->key == IC_RESULT (ic)->key)
1839 return 0; /* did not find */
1841 /* if assignment then check that right is not a bit */
1842 if (ASSIGNMENT (dic) && !POINTER_SET (dic))
1844 sym_link *etype = operandType (IC_RIGHT (dic));
1845 if (IS_BITFIELD (etype))
1848 /* if the result is on stack or iaccess then it must be
1849 the same atleast one of the operands */
1850 if (OP_SYMBOL (IC_RESULT (ic))->onStack ||
1851 OP_SYMBOL (IC_RESULT (ic))->iaccess)
1854 /* the operation has only one symbol
1855 operator then we can pack */
1856 if ((IC_LEFT (dic) && !IS_SYMOP (IC_LEFT (dic))) ||
1857 (IC_RIGHT (dic) && !IS_SYMOP (IC_RIGHT (dic))))
1860 if (!((IC_LEFT (dic) &&
1861 IC_RESULT (ic)->key == IC_LEFT (dic)->key) ||
1863 IC_RESULT (ic)->key == IC_RIGHT (dic)->key)))
1867 /* found the definition */
1868 /* replace the result with the result of */
1869 /* this assignment and remove this assignment */
1870 bitVectUnSetBit(OP_SYMBOL(IC_RESULT(dic))->defs,dic->key);
1871 IC_RESULT (dic) = IC_RESULT (ic);
1873 if (IS_ITEMP (IC_RESULT (dic)) && OP_SYMBOL (IC_RESULT (dic))->liveFrom > dic->seq)
1875 OP_SYMBOL (IC_RESULT (dic))->liveFrom = dic->seq;
1877 /* delete from liverange table also
1878 delete from all the points inbetween and the new
1880 for (sic = dic; sic != ic; sic = sic->next)
1882 bitVectUnSetBit (sic->rlive, IC_RESULT (ic)->key);
1883 if (IS_ITEMP (IC_RESULT (dic)))
1884 bitVectSetBit (sic->rlive, IC_RESULT (dic)->key);
1887 remiCodeFromeBBlock (ebp, ic);
1888 bitVectUnSetBit(OP_SYMBOL(IC_RESULT(ic))->defs,ic->key);
1889 hTabDeleteItem (&iCodehTab, ic->key, ic, DELETE_ITEM, NULL);
1890 OP_DEFS (IC_RESULT (dic)) = bitVectSetBit (OP_DEFS (IC_RESULT (dic)), dic->key);
1895 /*-----------------------------------------------------------------*/
1896 /* findAssignToSym : scanning backwards looks for first assig found */
1897 /*-----------------------------------------------------------------*/
1899 findAssignToSym (operand * op, iCode * ic)
1903 for (dic = ic->prev; dic; dic = dic->prev)
1906 /* if definition by assignment */
1907 if (dic->op == '=' &&
1908 !POINTER_SET (dic) &&
1909 IC_RESULT (dic)->key == op->key
1910 /* && IS_TRUE_SYMOP(IC_RIGHT(dic)) */
1914 /* we are interested only if defined in far space */
1915 /* or in stack space in case of + & - */
1917 /* if assigned to a non-symbol then return
1919 if (!IS_SYMOP (IC_RIGHT (dic)))
1922 /* if the symbol is in far space then
1924 if (isOperandInFarSpace (IC_RIGHT (dic)))
1927 /* for + & - operations make sure that
1928 if it is on the stack it is the same
1929 as one of the three operands */
1930 if ((ic->op == '+' || ic->op == '-') &&
1931 OP_SYMBOL (IC_RIGHT (dic))->onStack)
1934 if (IC_RESULT (ic)->key != IC_RIGHT (dic)->key &&
1935 IC_LEFT (ic)->key != IC_RIGHT (dic)->key &&
1936 IC_RIGHT (ic)->key != IC_RIGHT (dic)->key)
1944 /* if we find an usage then we cannot delete it */
1945 if (IC_LEFT (dic) && IC_LEFT (dic)->key == op->key)
1948 if (IC_RIGHT (dic) && IC_RIGHT (dic)->key == op->key)
1951 if (POINTER_SET (dic) && IC_RESULT (dic)->key == op->key)
1955 /* now make sure that the right side of dic
1956 is not defined between ic & dic */
1959 iCode *sic = dic->next;
1961 for (; sic != ic; sic = sic->next)
1962 if (IC_RESULT (sic) &&
1963 IC_RESULT (sic)->key == IC_RIGHT (dic)->key)
1972 /*-----------------------------------------------------------------*/
1973 /* packRegsForSupport :- reduce some registers for support calls */
1974 /*-----------------------------------------------------------------*/
1976 packRegsForSupport (iCode * ic, eBBlock * ebp)
1981 /* for the left & right operand :- look to see if the
1982 left was assigned a true symbol in far space in that
1983 case replace them */
1985 if (IS_ITEMP (IC_LEFT (ic)) &&
1986 OP_SYMBOL (IC_LEFT (ic))->liveTo <= ic->seq)
1988 dic = findAssignToSym (IC_LEFT (ic), ic);
1993 /* found it we need to remove it from the
1995 for (sic = dic; sic != ic; sic = sic->next) {
1996 bitVectUnSetBit (sic->rlive, IC_LEFT (ic)->key);
1997 sic->rlive = bitVectSetBit (sic->rlive, IC_RIGHT (dic)->key);
2000 OP_SYMBOL(IC_LEFT (ic))=OP_SYMBOL(IC_RIGHT (dic));
2001 OP_SYMBOL(IC_LEFT(ic))->liveTo = ic->seq;
2002 IC_LEFT (ic)->key = OP_SYMBOL(IC_RIGHT (dic))->key;
2003 remiCodeFromeBBlock (ebp, dic);
2004 bitVectUnSetBit(OP_SYMBOL(IC_RESULT(dic))->defs,dic->key);
2005 hTabDeleteItem (&iCodehTab, dic->key, dic, DELETE_ITEM, NULL);
2009 /* do the same for the right operand */
2012 IS_ITEMP (IC_RIGHT (ic)) &&
2013 OP_SYMBOL (IC_RIGHT (ic))->liveTo <= ic->seq)
2015 iCode *dic = findAssignToSym (IC_RIGHT (ic), ic);
2021 /* if this is a subtraction & the result
2022 is a true symbol in far space then don't pack */
2023 if (ic->op == '-' && IS_TRUE_SYMOP (IC_RESULT (dic)))
2025 sym_link *etype = getSpec (operandType (IC_RESULT (dic)));
2026 if (IN_FARSPACE (SPEC_OCLS (etype)))
2029 /* found it we need to remove it from the
2031 for (sic = dic; sic != ic; sic = sic->next) {
2032 bitVectUnSetBit (sic->rlive, IC_RIGHT (ic)->key);
2033 sic->rlive = bitVectSetBit (sic->rlive, IC_RIGHT (dic)->key);
2036 IC_RIGHT (ic)->operand.symOperand =
2037 IC_RIGHT (dic)->operand.symOperand;
2038 OP_SYMBOL(IC_RIGHT(ic))->liveTo = ic->seq;
2039 IC_RIGHT (ic)->key = IC_RIGHT (dic)->operand.symOperand->key;
2041 remiCodeFromeBBlock (ebp, dic);
2042 bitVectUnSetBit(OP_SYMBOL(IC_RESULT(dic))->defs,dic->key);
2043 hTabDeleteItem (&iCodehTab, dic->key, dic, DELETE_ITEM, NULL);
2050 #define IS_OP_RUONLY(x) (x && IS_SYMOP(x) && OP_SYMBOL(x)->ruonly)
2053 /*-----------------------------------------------------------------*/
2054 /* packRegsForOneuse : - will reduce some registers for single Use */
2055 /*-----------------------------------------------------------------*/
2057 packRegsForOneuse (iCode * ic, operand * op, eBBlock * ebp)
2062 /* if returning a literal then do nothing */
2066 /* only upto 2 bytes since we cannot predict
2067 the usage of b, & acc */
2068 if (getSize (operandType (op)) > (fReturnSizeMCS51 - 2))
2071 if (ic->op != RETURN &&
2073 !POINTER_SET (ic) &&
2077 if (ic->op == SEND && ic->argreg != 1) return NULL;
2079 /* this routine will mark the a symbol as used in one
2080 instruction use only && if the defintion is local
2081 (ie. within the basic block) && has only one definition &&
2082 that definiion is either a return value from a
2083 function or does not contain any variables in
2085 uses = bitVectCopy (OP_USES (op));
2086 bitVectUnSetBit (uses, ic->key); /* take away this iCode */
2087 if (!bitVectIsZero (uses)) /* has other uses */
2090 /* if it has only one defintion */
2091 if (bitVectnBitsOn (OP_DEFS (op)) > 1)
2092 return NULL; /* has more than one definition */
2094 /* get that definition */
2096 hTabItemWithKey (iCodehTab,
2097 bitVectFirstBit (OP_DEFS (op)))))
2100 /* if that only usage is a cast */
2101 if (dic->op == CAST) {
2102 /* to a bigger type */
2103 if (getSize(OP_SYM_TYPE(IC_RESULT(dic))) >
2104 getSize(OP_SYM_TYPE(IC_RIGHT(dic)))) {
2105 /* than we can not, since we cannot predict the usage of b & acc */
2110 /* found the definition now check if it is local */
2111 if (dic->seq < ebp->fSeq ||
2112 dic->seq > ebp->lSeq)
2113 return NULL; /* non-local */
2115 /* now check if it is the return from
2117 if (dic->op == CALL || dic->op == PCALL)
2119 if (ic->op != SEND && ic->op != RETURN &&
2120 !POINTER_SET(ic) && !POINTER_GET(ic))
2122 OP_SYMBOL (op)->ruonly = 1;
2129 /* otherwise check that the definition does
2130 not contain any symbols in far space */
2131 if (isOperandInFarSpace (IC_LEFT (dic)) ||
2132 isOperandInFarSpace (IC_RIGHT (dic)) ||
2133 IS_OP_RUONLY (IC_LEFT (ic)) ||
2134 IS_OP_RUONLY (IC_RIGHT (ic)))
2139 /* if pointer set then make sure the pointer
2141 if (POINTER_SET (dic) &&
2142 !IS_DATA_PTR (aggrToPtr (operandType (IC_RESULT (dic)), FALSE)))
2145 if (POINTER_GET (dic) &&
2146 !IS_DATA_PTR (aggrToPtr (operandType (IC_LEFT (dic)), FALSE)))
2151 /* also make sure the intervenening instructions
2152 don't have any thing in far space */
2153 for (dic = dic->next; dic && dic != ic && sic != ic; dic = dic->next)
2156 /* if there is an intervening function call then no */
2157 if (dic->op == CALL || dic->op == PCALL)
2159 /* if pointer set then make sure the pointer
2161 if (POINTER_SET (dic) &&
2162 !IS_DATA_PTR (aggrToPtr (operandType (IC_RESULT (dic)), FALSE)))
2165 if (POINTER_GET (dic) &&
2166 !IS_DATA_PTR (aggrToPtr (operandType (IC_LEFT (dic)), FALSE)))
2169 /* if address of & the result is remat the okay */
2170 if (dic->op == ADDRESS_OF &&
2171 OP_SYMBOL (IC_RESULT (dic))->remat)
2174 /* if operand has size of three or more & this
2175 operation is a '*','/' or '%' then 'b' may
2177 if ((dic->op == '%' || dic->op == '/' || dic->op == '*') &&
2178 getSize (operandType (op)) >= 3)
2181 /* if left or right or result is in far space */
2182 if (isOperandInFarSpace (IC_LEFT (dic)) ||
2183 isOperandInFarSpace (IC_RIGHT (dic)) ||
2184 isOperandInFarSpace (IC_RESULT (dic)) ||
2185 IS_OP_RUONLY (IC_LEFT (dic)) ||
2186 IS_OP_RUONLY (IC_RIGHT (dic)) ||
2187 IS_OP_RUONLY (IC_RESULT (dic)))
2191 /* if left or right or result is on stack */
2192 if (isOperandOnStack(IC_LEFT(dic)) ||
2193 isOperandOnStack(IC_RIGHT(dic)) ||
2194 isOperandOnStack(IC_RESULT(dic))) {
2199 OP_SYMBOL (op)->ruonly = 1;
2204 /*-----------------------------------------------------------------*/
2205 /* isBitwiseOptimizable - requirements of JEAN LOUIS VERN */
2206 /*-----------------------------------------------------------------*/
2208 isBitwiseOptimizable (iCode * ic)
2210 sym_link *ltype = getSpec (operandType (IC_LEFT (ic)));
2211 sym_link *rtype = getSpec (operandType (IC_RIGHT (ic)));
2213 /* bitwise operations are considered optimizable
2214 under the following conditions (Jean-Louis VERN)
2226 if (IS_LITERAL(rtype) ||
2227 (IS_BITVAR (ltype) && IN_BITSPACE (SPEC_OCLS (ltype))))
2233 /*-----------------------------------------------------------------*/
2234 /* packRegsForAccUse - pack registers for acc use */
2235 /*-----------------------------------------------------------------*/
2237 packRegsForAccUse (iCode * ic)
2241 /* if this is an aggregate, e.g. a one byte char array */
2242 if (IS_AGGREGATE(operandType(IC_RESULT(ic)))) {
2246 /* if we are calling a reentrant function that has stack parameters */
2247 if (ic->op == CALL &&
2248 IFFUNC_ISREENT(operandType(IC_LEFT(ic))) &&
2249 FUNC_HASSTACKPARM(operandType(IC_LEFT(ic))))
2252 if (ic->op == PCALL &&
2253 IFFUNC_ISREENT(operandType(IC_LEFT(ic))->next) &&
2254 FUNC_HASSTACKPARM(operandType(IC_LEFT(ic))->next))
2257 /* if + or - then it has to be one byte result */
2258 if ((ic->op == '+' || ic->op == '-')
2259 && getSize (operandType (IC_RESULT (ic))) > 1)
2262 /* if shift operation make sure right side is not a literal */
2263 if (ic->op == RIGHT_OP &&
2264 (isOperandLiteral (IC_RIGHT (ic)) ||
2265 getSize (operandType (IC_RESULT (ic))) > 1))
2268 if (ic->op == LEFT_OP &&
2269 (isOperandLiteral (IC_RIGHT (ic)) ||
2270 getSize (operandType (IC_RESULT (ic))) > 1))
2273 if (IS_BITWISE_OP (ic) &&
2274 getSize (operandType (IC_RESULT (ic))) > 1)
2278 /* has only one definition */
2279 if (bitVectnBitsOn (OP_DEFS (IC_RESULT (ic))) > 1)
2282 /* has only one use */
2283 if (bitVectnBitsOn (OP_USES (IC_RESULT (ic))) > 1)
2286 /* and the usage immediately follows this iCode */
2287 if (!(uic = hTabItemWithKey (iCodehTab,
2288 bitVectFirstBit (OP_USES (IC_RESULT (ic))))))
2291 if (ic->next != uic)
2294 /* if it is a conditional branch then we definitely can */
2298 if (uic->op == JUMPTABLE)
2301 /* if the usage is not is an assignment
2302 or an arithmetic / bitwise / shift operation then not */
2303 if (POINTER_SET (uic) &&
2304 getSize (aggrToPtr (operandType (IC_RESULT (uic)), FALSE)) > 1)
2307 if (uic->op != '=' &&
2308 !IS_ARITHMETIC_OP (uic) &&
2309 !IS_BITWISE_OP (uic) &&
2310 uic->op != LEFT_OP &&
2311 uic->op != RIGHT_OP)
2314 /* if used in ^ operation then make sure right is not a
2316 if (uic->op == '^' && isOperandLiteral (IC_RIGHT (uic)))
2319 /* if shift operation make sure right side is not a literal */
2320 if (uic->op == RIGHT_OP &&
2321 (isOperandLiteral (IC_RIGHT (uic)) ||
2322 getSize (operandType (IC_RESULT (uic))) > 1))
2325 if (uic->op == LEFT_OP &&
2326 (isOperandLiteral (IC_RIGHT (uic)) ||
2327 getSize (operandType (IC_RESULT (uic))) > 1))
2330 /* make sure that the result of this icode is not on the
2331 stack, since acc is used to compute stack offset */
2333 if (IS_TRUE_SYMOP (IC_RESULT (uic)) &&
2334 OP_SYMBOL (IC_RESULT (uic))->onStack)
2337 if (isOperandOnStack(IC_RESULT(uic)))
2341 /* if either one of them in far space then we cannot */
2342 if ((IS_TRUE_SYMOP (IC_LEFT (uic)) &&
2343 isOperandInFarSpace (IC_LEFT (uic))) ||
2344 (IS_TRUE_SYMOP (IC_RIGHT (uic)) &&
2345 isOperandInFarSpace (IC_RIGHT (uic))))
2348 /* if the usage has only one operand then we can */
2349 if (IC_LEFT (uic) == NULL ||
2350 IC_RIGHT (uic) == NULL)
2353 /* make sure this is on the left side if not
2354 a '+' since '+' is commutative */
2355 if (ic->op != '+' &&
2356 IC_LEFT (uic)->key != IC_RESULT (ic)->key)
2360 // this is too dangerous and need further restrictions
2363 /* if one of them is a literal then we can */
2364 if ((IC_LEFT (uic) && IS_OP_LITERAL (IC_LEFT (uic))) ||
2365 (IC_RIGHT (uic) && IS_OP_LITERAL (IC_RIGHT (uic))))
2367 OP_SYMBOL (IC_RESULT (ic))->accuse = 1;
2372 /* if the other one is not on stack then we can */
2373 if (IC_LEFT (uic)->key == IC_RESULT (ic)->key &&
2374 (IS_ITEMP (IC_RIGHT (uic)) ||
2375 (IS_TRUE_SYMOP (IC_RIGHT (uic)) &&
2376 !OP_SYMBOL (IC_RIGHT (uic))->onStack)))
2379 if (IC_RIGHT (uic)->key == IC_RESULT (ic)->key &&
2380 (IS_ITEMP (IC_LEFT (uic)) ||
2381 (IS_TRUE_SYMOP (IC_LEFT (uic)) &&
2382 !OP_SYMBOL (IC_LEFT (uic))->onStack)))
2388 OP_SYMBOL (IC_RESULT (ic))->accuse = 1;
2393 /*-----------------------------------------------------------------*/
2394 /* packForPush - hueristics to reduce iCode for pushing */
2395 /*-----------------------------------------------------------------*/
2397 packForPush (iCode * ic, eBBlock * ebp)
2402 if (ic->op != IPUSH || !IS_ITEMP (IC_LEFT (ic)))
2405 /* must have only definition & one usage */
2406 if (bitVectnBitsOn (OP_DEFS (IC_LEFT (ic))) != 1 ||
2407 bitVectnBitsOn (OP_USES (IC_LEFT (ic))) != 1)
2410 /* find the definition */
2411 if (!(dic = hTabItemWithKey (iCodehTab,
2412 bitVectFirstBit (OP_DEFS (IC_LEFT (ic))))))
2415 if (dic->op != '=' || POINTER_SET (dic))
2418 /* make sure the right side does not have any definitions
2420 dbv = OP_DEFS(IC_RIGHT(dic));
2421 for (lic = ic; lic && lic != dic ; lic = lic->prev) {
2422 if (bitVectBitValue(dbv,lic->key))
2425 /* make sure they have the same type */
2427 sym_link *itype=operandType(IC_LEFT(ic));
2428 sym_link *ditype=operandType(IC_RIGHT(dic));
2430 if (SPEC_USIGN(itype)!=SPEC_USIGN(ditype) ||
2431 SPEC_LONG(itype)!=SPEC_LONG(ditype))
2434 /* extend the live range of replaced operand if needed */
2435 if (OP_SYMBOL(IC_RIGHT(dic))->liveTo < ic->seq) {
2436 OP_SYMBOL(IC_RIGHT(dic))->liveTo = ic->seq;
2438 /* we now we know that it has one & only one def & use
2439 and the that the definition is an assignment */
2440 IC_LEFT (ic) = IC_RIGHT (dic);
2442 remiCodeFromeBBlock (ebp, dic);
2443 bitVectUnSetBit(OP_SYMBOL(IC_RESULT(dic))->defs,dic->key);
2444 hTabDeleteItem (&iCodehTab, dic->key, dic, DELETE_ITEM, NULL);
2447 /*-----------------------------------------------------------------*/
2448 /* packRegisters - does some transformations to reduce register */
2450 /*-----------------------------------------------------------------*/
2452 packRegisters (eBBlock * ebp)
2462 /* look for assignments of the form */
2463 /* iTempNN = TRueSym (someoperation) SomeOperand */
2465 /* TrueSym := iTempNN:1 */
2466 for (ic = ebp->sch; ic; ic = ic->next)
2468 /* find assignment of the form TrueSym := iTempNN:1 */
2469 if (ic->op == '=' && !POINTER_SET (ic))
2470 change += packRegsForAssign (ic, ebp);
2477 for (ic = ebp->sch; ic; ic = ic->next)
2479 /* if this is an itemp & result of an address of a true sym
2480 then mark this as rematerialisable */
2481 if (ic->op == ADDRESS_OF &&
2482 IS_ITEMP (IC_RESULT (ic)) &&
2483 IS_TRUE_SYMOP (IC_LEFT (ic)) &&
2484 bitVectnBitsOn (OP_DEFS (IC_RESULT (ic))) == 1 &&
2485 !OP_SYMBOL (IC_LEFT (ic))->onStack)
2488 OP_SYMBOL (IC_RESULT (ic))->remat = 1;
2489 OP_SYMBOL (IC_RESULT (ic))->rematiCode = ic;
2490 OP_SYMBOL (IC_RESULT (ic))->usl.spillLoc = NULL;
2494 /* if straight assignment then carry remat flag if
2495 this is the only definition */
2496 if (ic->op == '=' &&
2497 !POINTER_SET (ic) &&
2498 IS_SYMOP (IC_RIGHT (ic)) &&
2499 OP_SYMBOL (IC_RIGHT (ic))->remat &&
2500 !IS_CAST_ICODE(OP_SYMBOL (IC_RIGHT (ic))->rematiCode) &&
2501 bitVectnBitsOn (OP_SYMBOL (IC_RESULT (ic))->defs) <= 1)
2504 OP_SYMBOL (IC_RESULT (ic))->remat =
2505 OP_SYMBOL (IC_RIGHT (ic))->remat;
2506 OP_SYMBOL (IC_RESULT (ic))->rematiCode =
2507 OP_SYMBOL (IC_RIGHT (ic))->rematiCode;
2510 /* if cast to a generic pointer & the pointer being
2511 cast is remat, then we can remat this cast as well */
2512 if (ic->op == CAST &&
2513 IS_SYMOP(IC_RIGHT(ic)) &&
2514 OP_SYMBOL(IC_RIGHT(ic))->remat ) {
2515 sym_link *to_type = operandType(IC_LEFT(ic));
2516 sym_link *from_type = operandType(IC_RIGHT(ic));
2517 if (IS_GENPTR(to_type) && IS_PTR(from_type)) {
2518 OP_SYMBOL (IC_RESULT (ic))->remat = 1;
2519 OP_SYMBOL (IC_RESULT (ic))->rematiCode = ic;
2520 OP_SYMBOL (IC_RESULT (ic))->usl.spillLoc = NULL;
2524 /* if this is a +/- operation with a rematerizable
2525 then mark this as rematerializable as well */
2526 if ((ic->op == '+' || ic->op == '-') &&
2527 (IS_SYMOP (IC_LEFT (ic)) &&
2528 IS_ITEMP (IC_RESULT (ic)) &&
2529 IS_OP_LITERAL (IC_RIGHT (ic))) &&
2530 OP_SYMBOL (IC_LEFT (ic))->remat &&
2531 (!IS_SYMOP (IC_RIGHT (ic)) || !IS_CAST_ICODE(OP_SYMBOL (IC_RIGHT (ic))->rematiCode)) &&
2532 bitVectnBitsOn (OP_DEFS (IC_RESULT (ic))) == 1)
2534 OP_SYMBOL (IC_RESULT (ic))->remat = 1;
2535 OP_SYMBOL (IC_RESULT (ic))->rematiCode = ic;
2536 OP_SYMBOL (IC_RESULT (ic))->usl.spillLoc = NULL;
2539 /* mark the pointer usages */
2540 if (POINTER_SET (ic))
2541 OP_SYMBOL (IC_RESULT (ic))->uptr = 1;
2543 if (POINTER_GET (ic))
2544 OP_SYMBOL (IC_LEFT (ic))->uptr = 1;
2548 /* if we are using a symbol on the stack
2549 then we should say mcs51_ptrRegReq */
2550 if (ic->op == IFX && IS_SYMOP (IC_COND (ic)))
2551 mcs51_ptrRegReq += ((OP_SYMBOL (IC_COND (ic))->onStack ||
2552 OP_SYMBOL (IC_COND (ic))->iaccess) ? 1 : 0);
2553 else if (ic->op == JUMPTABLE && IS_SYMOP (IC_JTCOND (ic)))
2554 mcs51_ptrRegReq += ((OP_SYMBOL (IC_JTCOND (ic))->onStack ||
2555 OP_SYMBOL (IC_JTCOND (ic))->iaccess) ? 1 : 0);
2558 if (IS_SYMOP (IC_LEFT (ic)))
2559 mcs51_ptrRegReq += ((OP_SYMBOL (IC_LEFT (ic))->onStack ||
2560 OP_SYMBOL (IC_LEFT (ic))->iaccess) ? 1 : 0);
2561 if (IS_SYMOP (IC_RIGHT (ic)))
2562 mcs51_ptrRegReq += ((OP_SYMBOL (IC_RIGHT (ic))->onStack ||
2563 OP_SYMBOL (IC_RIGHT (ic))->iaccess) ? 1 : 0);
2564 if (IS_SYMOP (IC_RESULT (ic)))
2565 mcs51_ptrRegReq += ((OP_SYMBOL (IC_RESULT (ic))->onStack ||
2566 OP_SYMBOL (IC_RESULT (ic))->iaccess) ? 1 : 0);
2570 /* if the condition of an if instruction
2571 is defined in the previous instruction and
2572 this is the only usage then
2573 mark the itemp as a conditional */
2574 if ((IS_CONDITIONAL (ic) ||
2575 (IS_BITWISE_OP(ic) && isBitwiseOptimizable (ic))) &&
2576 ic->next && ic->next->op == IFX &&
2577 bitVectnBitsOn (OP_USES(IC_RESULT(ic)))==1 &&
2578 isOperandEqual (IC_RESULT (ic), IC_COND (ic->next)) &&
2579 OP_SYMBOL (IC_RESULT (ic))->liveTo <= ic->next->seq)
2581 OP_SYMBOL (IC_RESULT (ic))->regType = REG_CND;
2585 /* reduce for support function calls */
2586 if (ic->supportRtn || ic->op == '+' || ic->op == '-')
2587 packRegsForSupport (ic, ebp);
2589 /* some cases the redundant moves can
2590 can be eliminated for return statements */
2591 if ((ic->op == RETURN || (ic->op == SEND && ic->argreg == 1)) &&
2592 !isOperandInFarSpace (IC_LEFT (ic)) &&
2593 options.model == MODEL_SMALL) {
2594 if (0 && options.stackAuto) {
2595 /* we should check here if acc will be clobbered for stack
2596 offset calculations */
2598 packRegsForOneuse (ic, IC_LEFT (ic), ebp);
2602 /* if pointer set & left has a size more than
2603 one and right is not in far space */
2604 if (POINTER_SET (ic) &&
2605 !isOperandInFarSpace (IC_RIGHT (ic)) &&
2606 !OP_SYMBOL (IC_RESULT (ic))->remat &&
2607 !IS_OP_RUONLY (IC_RIGHT (ic)) &&
2608 getSize (aggrToPtr (operandType (IC_RESULT (ic)), FALSE)) > 1)
2610 packRegsForOneuse (ic, IC_RESULT (ic), ebp);
2612 /* if pointer get */
2613 if (POINTER_GET (ic) &&
2614 !isOperandInFarSpace (IC_RESULT (ic)) &&
2615 !OP_SYMBOL (IC_LEFT (ic))->remat &&
2616 !IS_OP_RUONLY (IC_RESULT (ic)) &&
2617 getSize (aggrToPtr (operandType (IC_LEFT (ic)), FALSE)) > 1)
2619 packRegsForOneuse (ic, IC_LEFT (ic), ebp);
2622 /* if this is cast for intergral promotion then
2623 check if only use of the definition of the
2624 operand being casted/ if yes then replace
2625 the result of that arithmetic operation with
2626 this result and get rid of the cast */
2629 sym_link *fromType = operandType (IC_RIGHT (ic));
2630 sym_link *toType = operandType (IC_LEFT (ic));
2632 if (IS_INTEGRAL (fromType) && IS_INTEGRAL (toType) &&
2633 getSize (fromType) != getSize (toType) &&
2634 SPEC_USIGN (fromType) == SPEC_USIGN (toType))
2637 iCode *dic = packRegsForOneuse (ic, IC_RIGHT (ic), ebp);
2640 if (IS_ARITHMETIC_OP (dic))
2642 bitVectUnSetBit(OP_SYMBOL(IC_RESULT(dic))->defs,dic->key);
2643 IC_RESULT (dic) = IC_RESULT (ic);
2644 remiCodeFromeBBlock (ebp, ic);
2645 bitVectUnSetBit(OP_SYMBOL(IC_RESULT(ic))->defs,ic->key);
2646 hTabDeleteItem (&iCodehTab, ic->key, ic, DELETE_ITEM, NULL);
2647 OP_DEFS (IC_RESULT (dic)) = bitVectSetBit (OP_DEFS (IC_RESULT (dic)), dic->key);
2651 OP_SYMBOL (IC_RIGHT (ic))->ruonly = 0;
2657 /* if the type from and type to are the same
2658 then if this is the only use then packit */
2659 if (compareType (operandType (IC_RIGHT (ic)),
2660 operandType (IC_LEFT (ic))) == 1)
2662 iCode *dic = packRegsForOneuse (ic, IC_RIGHT (ic), ebp);
2665 bitVectUnSetBit(OP_SYMBOL(IC_RESULT(dic))->defs,dic->key);
2666 IC_RESULT (dic) = IC_RESULT (ic);
2667 remiCodeFromeBBlock (ebp, ic);
2668 bitVectUnSetBit(OP_SYMBOL(IC_RESULT(ic))->defs,ic->key);
2669 hTabDeleteItem (&iCodehTab, ic->key, ic, DELETE_ITEM, NULL);
2670 OP_DEFS (IC_RESULT (dic)) = bitVectSetBit (OP_DEFS (IC_RESULT (dic)), dic->key);
2678 iTempNN := (some variable in farspace) V1
2683 if (ic->op == IPUSH)
2685 packForPush (ic, ebp);
2689 /* pack registers for accumulator use, when the
2690 result of an arithmetic or bit wise operation
2691 has only one use, that use is immediately following
2692 the defintion and the using iCode has only one
2693 operand or has two operands but one is literal &
2694 the result of that operation is not on stack then
2695 we can leave the result of this operation in acc:b
2697 if ((IS_ARITHMETIC_OP (ic)
2698 || IS_CONDITIONAL(ic)
2699 || IS_BITWISE_OP (ic)
2700 || ic->op == LEFT_OP || ic->op == RIGHT_OP || ic->op == CALL
2701 || (ic->op == ADDRESS_OF && isOperandOnStack (IC_LEFT (ic)))
2703 IS_ITEMP (IC_RESULT (ic)) &&
2704 getSize (operandType (IC_RESULT (ic))) <= 2)
2706 packRegsForAccUse (ic);
2710 /*-----------------------------------------------------------------*/
2711 /* assignRegisters - assigns registers to each live range as need */
2712 /*-----------------------------------------------------------------*/
2714 mcs51_assignRegisters (eBBlock ** ebbs, int count)
2719 setToNull ((void *) &_G.funcrUsed);
2720 setToNull ((void *) &_G.totRegAssigned);
2721 mcs51_ptrRegReq = _G.stackExtend = _G.dataExtend = 0;
2724 /* change assignments this will remove some
2725 live ranges reducing some register pressure */
2726 for (i = 0; i < count; i++)
2727 packRegisters (ebbs[i]);
2729 if (options.dump_pack)
2730 dumpEbbsToFileExt (DUMP_PACK, ebbs, count);
2732 /* first determine for each live range the number of
2733 registers & the type of registers required for each */
2736 /* and serially allocate registers */
2737 serialRegAssign (ebbs, count);
2742 /* if stack was extended then tell the user */
2745 /* werror(W_TOOMANY_SPILS,"stack", */
2746 /* _G.stackExtend,currFunc->name,""); */
2752 /* werror(W_TOOMANY_SPILS,"data space", */
2753 /* _G.dataExtend,currFunc->name,""); */
2757 /* after that create the register mask
2758 for each of the instruction */
2759 createRegMask (ebbs, count);
2761 /* redo that offsets for stacked automatic variables */
2762 redoStackOffsets ();
2764 if (options.dump_rassgn)
2766 dumpEbbsToFileExt (DUMP_RASSGN, ebbs, count);
2767 dumpLiveRanges (DUMP_LRANGE, liveRanges);
2770 /* do the overlaysegment stuff SDCCmem.c */
2771 doOverlays (ebbs, count);
2773 /* now get back the chain */
2774 ic = iCodeLabelOptimize (iCodeFromeBBlock (ebbs, count));
2778 /* free up any _G.stackSpil locations allocated */
2779 applyToSet (_G.stackSpil, deallocStackSpil);
2781 setToNull ((void **) &_G.stackSpil);
2782 setToNull ((void **) &_G.spiltSet);
2783 /* mark all registers as free */