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 and the
1601 pointer we are getting is rematerializable and
1604 if (bitVectnBitsOn (sym->defs) == 1 &&
1605 (ic = hTabItemWithKey (iCodehTab,
1606 bitVectFirstBit (sym->defs))) &&
1609 !IS_BITVAR (sym->etype))
1613 /* if remat in data space */
1614 if (OP_SYMBOL (IC_LEFT (ic))->remat &&
1615 !IS_CAST_ICODE(OP_SYMBOL (IC_LEFT (ic))->rematiCode) &&
1616 DCL_TYPE (aggrToPtr (sym->type, FALSE)) == POINTER)
1618 /* create a psuedo symbol & force a spil */
1619 symbol *psym = newSymbol (rematStr (OP_SYMBOL (IC_LEFT (ic))), 1);
1620 psym->type = sym->type;
1621 psym->etype = sym->etype;
1622 strcpy (psym->rname, psym->name);
1624 sym->usl.spillLoc = psym;
1625 #if 0 // an alternative fix for bug #480076
1626 /* now this is a useless assignment to itself */
1627 remiCodeFromeBBlock (ebbs, ic);
1629 /* now this really is an assignment to itself, make it so;
1630 it will be optimized out later */
1632 IC_RIGHT(ic)=IC_RESULT(ic);
1638 /* if in data space or idata space then try to
1639 allocate pointer register */
1643 /* if not then we require registers */
1644 sym->nRegs = ((IS_AGGREGATE (sym->type) || sym->isptr) ?
1645 getSize (sym->type = aggrToPtr (sym->type, FALSE)) :
1646 getSize (sym->type));
1650 fprintf (stderr, "allocated more than 4 or 0 registers for type ");
1651 printTypeChain (sym->type, stderr);
1652 fprintf (stderr, "\n");
1655 /* determine the type of register required */
1656 if (sym->nRegs == 1 &&
1657 IS_PTR (sym->type) &&
1659 sym->regType = REG_PTR;
1661 sym->regType = REG_GPR;
1665 /* for the first run we don't provide */
1666 /* registers for true symbols we will */
1667 /* see how things go */
1673 /*-----------------------------------------------------------------*/
1674 /* freeAllRegs - mark all registers as free */
1675 /*-----------------------------------------------------------------*/
1681 for (i = 0; i < mcs51_nRegs; i++)
1682 regs8051[i].isFree = 1;
1685 /*-----------------------------------------------------------------*/
1686 /* deallocStackSpil - this will set the stack pointer back */
1687 /*-----------------------------------------------------------------*/
1689 DEFSETFUNC (deallocStackSpil)
1697 /*-----------------------------------------------------------------*/
1698 /* farSpacePackable - returns the packable icode for far variables */
1699 /*-----------------------------------------------------------------*/
1701 farSpacePackable (iCode * ic)
1705 /* go thru till we find a definition for the
1706 symbol on the right */
1707 for (dic = ic->prev; dic; dic = dic->prev)
1709 /* if the definition is a call then no */
1710 if ((dic->op == CALL || dic->op == PCALL) &&
1711 IC_RESULT (dic)->key == IC_RIGHT (ic)->key)
1716 /* if shift by unknown amount then not */
1717 if ((dic->op == LEFT_OP || dic->op == RIGHT_OP) &&
1718 IC_RESULT (dic)->key == IC_RIGHT (ic)->key)
1721 /* if pointer get and size > 1 */
1722 if (POINTER_GET (dic) &&
1723 getSize (aggrToPtr (operandType (IC_LEFT (dic)), FALSE)) > 1)
1726 if (POINTER_SET (dic) &&
1727 getSize (aggrToPtr (operandType (IC_RESULT (dic)), FALSE)) > 1)
1730 /* if any three is a true symbol in far space */
1731 if (IC_RESULT (dic) &&
1732 IS_TRUE_SYMOP (IC_RESULT (dic)) &&
1733 isOperandInFarSpace (IC_RESULT (dic)))
1736 if (IC_RIGHT (dic) &&
1737 IS_TRUE_SYMOP (IC_RIGHT (dic)) &&
1738 isOperandInFarSpace (IC_RIGHT (dic)) &&
1739 !isOperandEqual (IC_RIGHT (dic), IC_RESULT (ic)))
1742 if (IC_LEFT (dic) &&
1743 IS_TRUE_SYMOP (IC_LEFT (dic)) &&
1744 isOperandInFarSpace (IC_LEFT (dic)) &&
1745 !isOperandEqual (IC_LEFT (dic), IC_RESULT (ic)))
1748 if (isOperandEqual (IC_RIGHT (ic), IC_RESULT (dic)))
1750 if ((dic->op == LEFT_OP ||
1751 dic->op == RIGHT_OP ||
1753 IS_OP_LITERAL (IC_RIGHT (dic)))
1763 /*-----------------------------------------------------------------*/
1764 /* packRegsForAssign - register reduction for assignment */
1765 /*-----------------------------------------------------------------*/
1767 packRegsForAssign (iCode * ic, eBBlock * ebp)
1770 //sym_link *etype = operandType (IC_RIGHT (ic));
1772 if (!IS_ITEMP (IC_RIGHT (ic)) ||
1773 OP_SYMBOL (IC_RIGHT (ic))->isind ||
1774 OP_LIVETO (IC_RIGHT (ic)) > ic->seq
1775 /* why? || IS_BITFIELD (etype) */ )
1780 /* if the true symbol is defined in far space or on stack
1781 then we should not since this will increase register pressure */
1782 if (isOperandInFarSpace(IC_RESULT(ic)) && !farSpacePackable(ic)) {
1786 /* find the definition of iTempNN scanning backwards if we find a
1787 a use of the true symbol in before we find the definition then
1789 for (dic = ic->prev; dic; dic = dic->prev)
1791 /* if there is a function call then don't pack it */
1792 if ((dic->op == CALL || dic->op == PCALL))
1801 if (IS_TRUE_SYMOP (IC_RESULT (dic)) &&
1802 IS_OP_VOLATILE (IC_RESULT (dic)))
1808 if (IS_SYMOP (IC_RESULT (dic)) &&
1809 IC_RESULT (dic)->key == IC_RIGHT (ic)->key)
1811 if (POINTER_SET (dic))
1817 if (IS_SYMOP (IC_RIGHT (dic)) &&
1818 (IC_RIGHT (dic)->key == IC_RESULT (ic)->key ||
1819 IC_RIGHT (dic)->key == IC_RIGHT (ic)->key))
1825 if (IS_SYMOP (IC_LEFT (dic)) &&
1826 (IC_LEFT (dic)->key == IC_RESULT (ic)->key ||
1827 IC_LEFT (dic)->key == IC_RIGHT (ic)->key))
1833 if (POINTER_SET (dic) &&
1834 IC_RESULT (dic)->key == IC_RESULT (ic)->key)
1842 return 0; /* did not find */
1844 /* if assignment then check that right is not a bit */
1845 if (ASSIGNMENT (dic) && !POINTER_SET (dic))
1847 sym_link *etype = operandType (IC_RIGHT (dic));
1848 if (IS_BITFIELD (etype))
1851 /* if the result is on stack or iaccess then it must be
1852 the same atleast one of the operands */
1853 if (OP_SYMBOL (IC_RESULT (ic))->onStack ||
1854 OP_SYMBOL (IC_RESULT (ic))->iaccess)
1857 /* the operation has only one symbol
1858 operator then we can pack */
1859 if ((IC_LEFT (dic) && !IS_SYMOP (IC_LEFT (dic))) ||
1860 (IC_RIGHT (dic) && !IS_SYMOP (IC_RIGHT (dic))))
1863 if (!((IC_LEFT (dic) &&
1864 IC_RESULT (ic)->key == IC_LEFT (dic)->key) ||
1866 IC_RESULT (ic)->key == IC_RIGHT (dic)->key)))
1870 /* found the definition */
1871 /* replace the result with the result of */
1872 /* this assignment and remove this assignment */
1873 bitVectUnSetBit(OP_SYMBOL(IC_RESULT(dic))->defs,dic->key);
1874 IC_RESULT (dic) = IC_RESULT (ic);
1876 if (IS_ITEMP (IC_RESULT (dic)) && OP_SYMBOL (IC_RESULT (dic))->liveFrom > dic->seq)
1878 OP_SYMBOL (IC_RESULT (dic))->liveFrom = dic->seq;
1880 /* delete from liverange table also
1881 delete from all the points inbetween and the new
1883 for (sic = dic; sic != ic; sic = sic->next)
1885 bitVectUnSetBit (sic->rlive, IC_RESULT (ic)->key);
1886 if (IS_ITEMP (IC_RESULT (dic)))
1887 bitVectSetBit (sic->rlive, IC_RESULT (dic)->key);
1890 remiCodeFromeBBlock (ebp, ic);
1891 bitVectUnSetBit(OP_SYMBOL(IC_RESULT(ic))->defs,ic->key);
1892 hTabDeleteItem (&iCodehTab, ic->key, ic, DELETE_ITEM, NULL);
1893 OP_DEFS (IC_RESULT (dic)) = bitVectSetBit (OP_DEFS (IC_RESULT (dic)), dic->key);
1898 /*-----------------------------------------------------------------*/
1899 /* findAssignToSym : scanning backwards looks for first assig found */
1900 /*-----------------------------------------------------------------*/
1902 findAssignToSym (operand * op, iCode * ic)
1906 for (dic = ic->prev; dic; dic = dic->prev)
1909 /* if definition by assignment */
1910 if (dic->op == '=' &&
1911 !POINTER_SET (dic) &&
1912 IC_RESULT (dic)->key == op->key
1913 /* && IS_TRUE_SYMOP(IC_RIGHT(dic)) */
1917 /* we are interested only if defined in far space */
1918 /* or in stack space in case of + & - */
1920 /* if assigned to a non-symbol then return
1922 if (!IS_SYMOP (IC_RIGHT (dic)))
1925 /* if the symbol is in far space then
1927 if (isOperandInFarSpace (IC_RIGHT (dic)))
1930 /* for + & - operations make sure that
1931 if it is on the stack it is the same
1932 as one of the three operands */
1933 if ((ic->op == '+' || ic->op == '-') &&
1934 OP_SYMBOL (IC_RIGHT (dic))->onStack)
1937 if (IC_RESULT (ic)->key != IC_RIGHT (dic)->key &&
1938 IC_LEFT (ic)->key != IC_RIGHT (dic)->key &&
1939 IC_RIGHT (ic)->key != IC_RIGHT (dic)->key)
1947 /* if we find an usage then we cannot delete it */
1948 if (IC_LEFT (dic) && IC_LEFT (dic)->key == op->key)
1951 if (IC_RIGHT (dic) && IC_RIGHT (dic)->key == op->key)
1954 if (POINTER_SET (dic) && IC_RESULT (dic)->key == op->key)
1958 /* now make sure that the right side of dic
1959 is not defined between ic & dic */
1962 iCode *sic = dic->next;
1964 for (; sic != ic; sic = sic->next)
1965 if (IC_RESULT (sic) &&
1966 IC_RESULT (sic)->key == IC_RIGHT (dic)->key)
1975 /*-----------------------------------------------------------------*/
1976 /* packRegsForSupport :- reduce some registers for support calls */
1977 /*-----------------------------------------------------------------*/
1979 packRegsForSupport (iCode * ic, eBBlock * ebp)
1984 /* for the left & right operand :- look to see if the
1985 left was assigned a true symbol in far space in that
1986 case replace them */
1988 if (IS_ITEMP (IC_LEFT (ic)) &&
1989 OP_SYMBOL (IC_LEFT (ic))->liveTo <= ic->seq)
1991 dic = findAssignToSym (IC_LEFT (ic), ic);
1996 /* found it we need to remove it from the
1998 for (sic = dic; sic != ic; sic = sic->next) {
1999 bitVectUnSetBit (sic->rlive, IC_LEFT (ic)->key);
2000 sic->rlive = bitVectSetBit (sic->rlive, IC_RIGHT (dic)->key);
2003 OP_SYMBOL(IC_LEFT (ic))=OP_SYMBOL(IC_RIGHT (dic));
2004 OP_SYMBOL(IC_LEFT(ic))->liveTo = ic->seq;
2005 IC_LEFT (ic)->key = OP_SYMBOL(IC_RIGHT (dic))->key;
2006 remiCodeFromeBBlock (ebp, dic);
2007 bitVectUnSetBit(OP_SYMBOL(IC_RESULT(dic))->defs,dic->key);
2008 hTabDeleteItem (&iCodehTab, dic->key, dic, DELETE_ITEM, NULL);
2012 /* do the same for the right operand */
2015 IS_ITEMP (IC_RIGHT (ic)) &&
2016 OP_SYMBOL (IC_RIGHT (ic))->liveTo <= ic->seq)
2018 iCode *dic = findAssignToSym (IC_RIGHT (ic), ic);
2024 /* if this is a subtraction & the result
2025 is a true symbol in far space then don't pack */
2026 if (ic->op == '-' && IS_TRUE_SYMOP (IC_RESULT (dic)))
2028 sym_link *etype = getSpec (operandType (IC_RESULT (dic)));
2029 if (IN_FARSPACE (SPEC_OCLS (etype)))
2032 /* found it we need to remove it from the
2034 for (sic = dic; sic != ic; sic = sic->next) {
2035 bitVectUnSetBit (sic->rlive, IC_RIGHT (ic)->key);
2036 sic->rlive = bitVectSetBit (sic->rlive, IC_RIGHT (dic)->key);
2039 IC_RIGHT (ic)->operand.symOperand =
2040 IC_RIGHT (dic)->operand.symOperand;
2041 OP_SYMBOL(IC_RIGHT(ic))->liveTo = ic->seq;
2042 IC_RIGHT (ic)->key = IC_RIGHT (dic)->operand.symOperand->key;
2044 remiCodeFromeBBlock (ebp, dic);
2045 bitVectUnSetBit(OP_SYMBOL(IC_RESULT(dic))->defs,dic->key);
2046 hTabDeleteItem (&iCodehTab, dic->key, dic, DELETE_ITEM, NULL);
2053 #define IS_OP_RUONLY(x) (x && IS_SYMOP(x) && OP_SYMBOL(x)->ruonly)
2056 /*-----------------------------------------------------------------*/
2057 /* packRegsForOneuse : - will reduce some registers for single Use */
2058 /*-----------------------------------------------------------------*/
2060 packRegsForOneuse (iCode * ic, operand * op, eBBlock * ebp)
2065 /* if returning a literal then do nothing */
2069 /* only upto 2 bytes since we cannot predict
2070 the usage of b, & acc */
2071 if (getSize (operandType (op)) > (fReturnSizeMCS51 - 2))
2074 if (ic->op != RETURN &&
2076 !POINTER_SET (ic) &&
2080 if (ic->op == SEND && ic->argreg != 1) return NULL;
2082 /* this routine will mark the a symbol as used in one
2083 instruction use only && if the defintion is local
2084 (ie. within the basic block) && has only one definition &&
2085 that definiion is either a return value from a
2086 function or does not contain any variables in
2088 uses = bitVectCopy (OP_USES (op));
2089 bitVectUnSetBit (uses, ic->key); /* take away this iCode */
2090 if (!bitVectIsZero (uses)) /* has other uses */
2093 /* if it has only one defintion */
2094 if (bitVectnBitsOn (OP_DEFS (op)) > 1)
2095 return NULL; /* has more than one definition */
2097 /* get that definition */
2099 hTabItemWithKey (iCodehTab,
2100 bitVectFirstBit (OP_DEFS (op)))))
2103 /* if that only usage is a cast */
2104 if (dic->op == CAST) {
2105 /* to a bigger type */
2106 if (getSize(OP_SYM_TYPE(IC_RESULT(dic))) >
2107 getSize(OP_SYM_TYPE(IC_RIGHT(dic)))) {
2108 /* than we can not, since we cannot predict the usage of b & acc */
2113 /* found the definition now check if it is local */
2114 if (dic->seq < ebp->fSeq ||
2115 dic->seq > ebp->lSeq)
2116 return NULL; /* non-local */
2118 /* now check if it is the return from
2120 if (dic->op == CALL || dic->op == PCALL)
2122 if (ic->op != SEND && ic->op != RETURN &&
2123 !POINTER_SET(ic) && !POINTER_GET(ic))
2125 OP_SYMBOL (op)->ruonly = 1;
2132 /* otherwise check that the definition does
2133 not contain any symbols in far space */
2134 if (isOperandInFarSpace (IC_LEFT (dic)) ||
2135 isOperandInFarSpace (IC_RIGHT (dic)) ||
2136 IS_OP_RUONLY (IC_LEFT (ic)) ||
2137 IS_OP_RUONLY (IC_RIGHT (ic)))
2142 /* if pointer set then make sure the pointer
2144 if (POINTER_SET (dic) &&
2145 !IS_DATA_PTR (aggrToPtr (operandType (IC_RESULT (dic)), FALSE)))
2148 if (POINTER_GET (dic) &&
2149 !IS_DATA_PTR (aggrToPtr (operandType (IC_LEFT (dic)), FALSE)))
2154 /* also make sure the intervenening instructions
2155 don't have any thing in far space */
2156 for (dic = dic->next; dic && dic != ic && sic != ic; dic = dic->next)
2159 /* if there is an intervening function call then no */
2160 if (dic->op == CALL || dic->op == PCALL)
2162 /* if pointer set then make sure the pointer
2164 if (POINTER_SET (dic) &&
2165 !IS_DATA_PTR (aggrToPtr (operandType (IC_RESULT (dic)), FALSE)))
2168 if (POINTER_GET (dic) &&
2169 !IS_DATA_PTR (aggrToPtr (operandType (IC_LEFT (dic)), FALSE)))
2172 /* if address of & the result is remat the okay */
2173 if (dic->op == ADDRESS_OF &&
2174 OP_SYMBOL (IC_RESULT (dic))->remat)
2177 /* if operand has size of three or more & this
2178 operation is a '*','/' or '%' then 'b' may
2180 if ((dic->op == '%' || dic->op == '/' || dic->op == '*') &&
2181 getSize (operandType (op)) >= 3)
2184 /* if left or right or result is in far space */
2185 if (isOperandInFarSpace (IC_LEFT (dic)) ||
2186 isOperandInFarSpace (IC_RIGHT (dic)) ||
2187 isOperandInFarSpace (IC_RESULT (dic)) ||
2188 IS_OP_RUONLY (IC_LEFT (dic)) ||
2189 IS_OP_RUONLY (IC_RIGHT (dic)) ||
2190 IS_OP_RUONLY (IC_RESULT (dic)))
2194 /* if left or right or result is on stack */
2195 if (isOperandOnStack(IC_LEFT(dic)) ||
2196 isOperandOnStack(IC_RIGHT(dic)) ||
2197 isOperandOnStack(IC_RESULT(dic))) {
2202 OP_SYMBOL (op)->ruonly = 1;
2207 /*-----------------------------------------------------------------*/
2208 /* isBitwiseOptimizable - requirements of JEAN LOUIS VERN */
2209 /*-----------------------------------------------------------------*/
2211 isBitwiseOptimizable (iCode * ic)
2213 sym_link *ltype = getSpec (operandType (IC_LEFT (ic)));
2214 sym_link *rtype = getSpec (operandType (IC_RIGHT (ic)));
2216 /* bitwise operations are considered optimizable
2217 under the following conditions (Jean-Louis VERN)
2229 if (IS_LITERAL(rtype) ||
2230 (IS_BITVAR (ltype) && IN_BITSPACE (SPEC_OCLS (ltype))))
2236 /*-----------------------------------------------------------------*/
2237 /* packRegsForAccUse - pack registers for acc use */
2238 /*-----------------------------------------------------------------*/
2240 packRegsForAccUse (iCode * ic)
2244 /* if this is an aggregate, e.g. a one byte char array */
2245 if (IS_AGGREGATE(operandType(IC_RESULT(ic)))) {
2249 /* if we are calling a reentrant function that has stack parameters */
2250 if (ic->op == CALL &&
2251 IFFUNC_ISREENT(operandType(IC_LEFT(ic))) &&
2252 FUNC_HASSTACKPARM(operandType(IC_LEFT(ic))))
2255 if (ic->op == PCALL &&
2256 IFFUNC_ISREENT(operandType(IC_LEFT(ic))->next) &&
2257 FUNC_HASSTACKPARM(operandType(IC_LEFT(ic))->next))
2260 /* if + or - then it has to be one byte result */
2261 if ((ic->op == '+' || ic->op == '-')
2262 && getSize (operandType (IC_RESULT (ic))) > 1)
2265 /* if shift operation make sure right side is not a literal */
2266 if (ic->op == RIGHT_OP &&
2267 (isOperandLiteral (IC_RIGHT (ic)) ||
2268 getSize (operandType (IC_RESULT (ic))) > 1))
2271 if (ic->op == LEFT_OP &&
2272 (isOperandLiteral (IC_RIGHT (ic)) ||
2273 getSize (operandType (IC_RESULT (ic))) > 1))
2276 if (IS_BITWISE_OP (ic) &&
2277 getSize (operandType (IC_RESULT (ic))) > 1)
2281 /* has only one definition */
2282 if (bitVectnBitsOn (OP_DEFS (IC_RESULT (ic))) > 1)
2285 /* has only one use */
2286 if (bitVectnBitsOn (OP_USES (IC_RESULT (ic))) > 1)
2289 /* and the usage immediately follows this iCode */
2290 if (!(uic = hTabItemWithKey (iCodehTab,
2291 bitVectFirstBit (OP_USES (IC_RESULT (ic))))))
2294 if (ic->next != uic)
2297 /* if it is a conditional branch then we definitely can */
2301 if (uic->op == JUMPTABLE)
2304 /* if the usage is not is an assignment
2305 or an arithmetic / bitwise / shift operation then not */
2306 if (POINTER_SET (uic) &&
2307 getSize (aggrToPtr (operandType (IC_RESULT (uic)), FALSE)) > 1)
2310 if (uic->op != '=' &&
2311 !IS_ARITHMETIC_OP (uic) &&
2312 !IS_BITWISE_OP (uic) &&
2313 uic->op != LEFT_OP &&
2314 uic->op != RIGHT_OP)
2317 /* if used in ^ operation then make sure right is not a
2319 if (uic->op == '^' && isOperandLiteral (IC_RIGHT (uic)))
2322 /* if shift operation make sure right side is not a literal */
2323 if (uic->op == RIGHT_OP &&
2324 (isOperandLiteral (IC_RIGHT (uic)) ||
2325 getSize (operandType (IC_RESULT (uic))) > 1))
2328 if (uic->op == LEFT_OP &&
2329 (isOperandLiteral (IC_RIGHT (uic)) ||
2330 getSize (operandType (IC_RESULT (uic))) > 1))
2333 /* make sure that the result of this icode is not on the
2334 stack, since acc is used to compute stack offset */
2336 if (IS_TRUE_SYMOP (IC_RESULT (uic)) &&
2337 OP_SYMBOL (IC_RESULT (uic))->onStack)
2340 if (isOperandOnStack(IC_RESULT(uic)))
2344 /* if either one of them in far space then we cannot */
2345 if ((IS_TRUE_SYMOP (IC_LEFT (uic)) &&
2346 isOperandInFarSpace (IC_LEFT (uic))) ||
2347 (IS_TRUE_SYMOP (IC_RIGHT (uic)) &&
2348 isOperandInFarSpace (IC_RIGHT (uic))))
2351 /* if the usage has only one operand then we can */
2352 if (IC_LEFT (uic) == NULL ||
2353 IC_RIGHT (uic) == NULL)
2356 /* make sure this is on the left side if not
2357 a '+' since '+' is commutative */
2358 if (ic->op != '+' &&
2359 IC_LEFT (uic)->key != IC_RESULT (ic)->key)
2363 // this is too dangerous and need further restrictions
2366 /* if one of them is a literal then we can */
2367 if ((IC_LEFT (uic) && IS_OP_LITERAL (IC_LEFT (uic))) ||
2368 (IC_RIGHT (uic) && IS_OP_LITERAL (IC_RIGHT (uic))))
2370 OP_SYMBOL (IC_RESULT (ic))->accuse = 1;
2375 /* if the other one is not on stack then we can */
2376 if (IC_LEFT (uic)->key == IC_RESULT (ic)->key &&
2377 (IS_ITEMP (IC_RIGHT (uic)) ||
2378 (IS_TRUE_SYMOP (IC_RIGHT (uic)) &&
2379 !OP_SYMBOL (IC_RIGHT (uic))->onStack)))
2382 if (IC_RIGHT (uic)->key == IC_RESULT (ic)->key &&
2383 (IS_ITEMP (IC_LEFT (uic)) ||
2384 (IS_TRUE_SYMOP (IC_LEFT (uic)) &&
2385 !OP_SYMBOL (IC_LEFT (uic))->onStack)))
2391 OP_SYMBOL (IC_RESULT (ic))->accuse = 1;
2396 /*-----------------------------------------------------------------*/
2397 /* packForPush - hueristics to reduce iCode for pushing */
2398 /*-----------------------------------------------------------------*/
2400 packForPush (iCode * ic, eBBlock * ebp)
2405 if (ic->op != IPUSH || !IS_ITEMP (IC_LEFT (ic)))
2408 /* must have only definition & one usage */
2409 if (bitVectnBitsOn (OP_DEFS (IC_LEFT (ic))) != 1 ||
2410 bitVectnBitsOn (OP_USES (IC_LEFT (ic))) != 1)
2413 /* find the definition */
2414 if (!(dic = hTabItemWithKey (iCodehTab,
2415 bitVectFirstBit (OP_DEFS (IC_LEFT (ic))))))
2418 if (dic->op != '=' || POINTER_SET (dic))
2421 /* make sure the right side does not have any definitions
2423 dbv = OP_DEFS(IC_RIGHT(dic));
2424 for (lic = ic; lic && lic != dic ; lic = lic->prev) {
2425 if (bitVectBitValue(dbv,lic->key))
2428 /* make sure they have the same type */
2430 sym_link *itype=operandType(IC_LEFT(ic));
2431 sym_link *ditype=operandType(IC_RIGHT(dic));
2433 if (SPEC_USIGN(itype)!=SPEC_USIGN(ditype) ||
2434 SPEC_LONG(itype)!=SPEC_LONG(ditype))
2437 /* extend the live range of replaced operand if needed */
2438 if (OP_SYMBOL(IC_RIGHT(dic))->liveTo < ic->seq) {
2439 OP_SYMBOL(IC_RIGHT(dic))->liveTo = ic->seq;
2441 /* we now we know that it has one & only one def & use
2442 and the that the definition is an assignment */
2443 IC_LEFT (ic) = IC_RIGHT (dic);
2445 remiCodeFromeBBlock (ebp, dic);
2446 bitVectUnSetBit(OP_SYMBOL(IC_RESULT(dic))->defs,dic->key);
2447 hTabDeleteItem (&iCodehTab, dic->key, dic, DELETE_ITEM, NULL);
2450 /*-----------------------------------------------------------------*/
2451 /* packRegisters - does some transformations to reduce register */
2453 /*-----------------------------------------------------------------*/
2455 packRegisters (eBBlock * ebp)
2465 /* look for assignments of the form */
2466 /* iTempNN = TRueSym (someoperation) SomeOperand */
2468 /* TrueSym := iTempNN:1 */
2469 for (ic = ebp->sch; ic; ic = ic->next)
2471 /* find assignment of the form TrueSym := iTempNN:1 */
2472 if (ic->op == '=' && !POINTER_SET (ic))
2473 change += packRegsForAssign (ic, ebp);
2480 for (ic = ebp->sch; ic; ic = ic->next)
2482 /* if this is an itemp & result of an address of a true sym
2483 then mark this as rematerialisable */
2484 if (ic->op == ADDRESS_OF &&
2485 IS_ITEMP (IC_RESULT (ic)) &&
2486 IS_TRUE_SYMOP (IC_LEFT (ic)) &&
2487 bitVectnBitsOn (OP_DEFS (IC_RESULT (ic))) == 1 &&
2488 !OP_SYMBOL (IC_LEFT (ic))->onStack)
2491 OP_SYMBOL (IC_RESULT (ic))->remat = 1;
2492 OP_SYMBOL (IC_RESULT (ic))->rematiCode = ic;
2493 OP_SYMBOL (IC_RESULT (ic))->usl.spillLoc = NULL;
2497 /* if straight assignment then carry remat flag if
2498 this is the only definition */
2499 if (ic->op == '=' &&
2500 !POINTER_SET (ic) &&
2501 IS_SYMOP (IC_RIGHT (ic)) &&
2502 OP_SYMBOL (IC_RIGHT (ic))->remat &&
2503 !IS_CAST_ICODE(OP_SYMBOL (IC_RIGHT (ic))->rematiCode) &&
2504 bitVectnBitsOn (OP_SYMBOL (IC_RESULT (ic))->defs) <= 1)
2507 OP_SYMBOL (IC_RESULT (ic))->remat =
2508 OP_SYMBOL (IC_RIGHT (ic))->remat;
2509 OP_SYMBOL (IC_RESULT (ic))->rematiCode =
2510 OP_SYMBOL (IC_RIGHT (ic))->rematiCode;
2513 /* if cast to a generic pointer & the pointer being
2514 cast is remat, then we can remat this cast as well */
2515 if (ic->op == CAST &&
2516 IS_SYMOP(IC_RIGHT(ic)) &&
2517 OP_SYMBOL(IC_RIGHT(ic))->remat ) {
2518 sym_link *to_type = operandType(IC_LEFT(ic));
2519 sym_link *from_type = operandType(IC_RIGHT(ic));
2520 if (IS_GENPTR(to_type) && IS_PTR(from_type)) {
2521 OP_SYMBOL (IC_RESULT (ic))->remat = 1;
2522 OP_SYMBOL (IC_RESULT (ic))->rematiCode = ic;
2523 OP_SYMBOL (IC_RESULT (ic))->usl.spillLoc = NULL;
2527 /* if this is a +/- operation with a rematerizable
2528 then mark this as rematerializable as well */
2529 if ((ic->op == '+' || ic->op == '-') &&
2530 (IS_SYMOP (IC_LEFT (ic)) &&
2531 IS_ITEMP (IC_RESULT (ic)) &&
2532 IS_OP_LITERAL (IC_RIGHT (ic))) &&
2533 OP_SYMBOL (IC_LEFT (ic))->remat &&
2534 (!IS_SYMOP (IC_RIGHT (ic)) || !IS_CAST_ICODE(OP_SYMBOL (IC_RIGHT (ic))->rematiCode)) &&
2535 bitVectnBitsOn (OP_DEFS (IC_RESULT (ic))) == 1)
2537 OP_SYMBOL (IC_RESULT (ic))->remat = 1;
2538 OP_SYMBOL (IC_RESULT (ic))->rematiCode = ic;
2539 OP_SYMBOL (IC_RESULT (ic))->usl.spillLoc = NULL;
2542 /* mark the pointer usages */
2543 if (POINTER_SET (ic))
2544 OP_SYMBOL (IC_RESULT (ic))->uptr = 1;
2546 if (POINTER_GET (ic))
2547 OP_SYMBOL (IC_LEFT (ic))->uptr = 1;
2551 /* if we are using a symbol on the stack
2552 then we should say mcs51_ptrRegReq */
2553 if (ic->op == IFX && IS_SYMOP (IC_COND (ic)))
2554 mcs51_ptrRegReq += ((OP_SYMBOL (IC_COND (ic))->onStack ||
2555 OP_SYMBOL (IC_COND (ic))->iaccess) ? 1 : 0);
2556 else if (ic->op == JUMPTABLE && IS_SYMOP (IC_JTCOND (ic)))
2557 mcs51_ptrRegReq += ((OP_SYMBOL (IC_JTCOND (ic))->onStack ||
2558 OP_SYMBOL (IC_JTCOND (ic))->iaccess) ? 1 : 0);
2561 if (IS_SYMOP (IC_LEFT (ic)))
2562 mcs51_ptrRegReq += ((OP_SYMBOL (IC_LEFT (ic))->onStack ||
2563 OP_SYMBOL (IC_LEFT (ic))->iaccess) ? 1 : 0);
2564 if (IS_SYMOP (IC_RIGHT (ic)))
2565 mcs51_ptrRegReq += ((OP_SYMBOL (IC_RIGHT (ic))->onStack ||
2566 OP_SYMBOL (IC_RIGHT (ic))->iaccess) ? 1 : 0);
2567 if (IS_SYMOP (IC_RESULT (ic)))
2568 mcs51_ptrRegReq += ((OP_SYMBOL (IC_RESULT (ic))->onStack ||
2569 OP_SYMBOL (IC_RESULT (ic))->iaccess) ? 1 : 0);
2573 /* if the condition of an if instruction
2574 is defined in the previous instruction and
2575 this is the only usage then
2576 mark the itemp as a conditional */
2577 if ((IS_CONDITIONAL (ic) ||
2578 (IS_BITWISE_OP(ic) && isBitwiseOptimizable (ic))) &&
2579 ic->next && ic->next->op == IFX &&
2580 bitVectnBitsOn (OP_USES(IC_RESULT(ic)))==1 &&
2581 isOperandEqual (IC_RESULT (ic), IC_COND (ic->next)) &&
2582 OP_SYMBOL (IC_RESULT (ic))->liveTo <= ic->next->seq)
2584 OP_SYMBOL (IC_RESULT (ic))->regType = REG_CND;
2588 /* reduce for support function calls */
2589 if (ic->supportRtn || ic->op == '+' || ic->op == '-')
2590 packRegsForSupport (ic, ebp);
2592 /* some cases the redundant moves can
2593 can be eliminated for return statements */
2594 if ((ic->op == RETURN || (ic->op == SEND && ic->argreg == 1)) &&
2595 !isOperandInFarSpace (IC_LEFT (ic)) &&
2596 options.model == MODEL_SMALL) {
2597 if (0 && options.stackAuto) {
2598 /* we should check here if acc will be clobbered for stack
2599 offset calculations */
2601 packRegsForOneuse (ic, IC_LEFT (ic), ebp);
2605 /* if pointer set & left has a size more than
2606 one and right is not in far space */
2607 if (POINTER_SET (ic) &&
2608 !isOperandInFarSpace (IC_RIGHT (ic)) &&
2609 !OP_SYMBOL (IC_RESULT (ic))->remat &&
2610 !IS_OP_RUONLY (IC_RIGHT (ic)) &&
2611 getSize (aggrToPtr (operandType (IC_RESULT (ic)), FALSE)) > 1)
2613 packRegsForOneuse (ic, IC_RESULT (ic), ebp);
2615 /* if pointer get */
2616 if (POINTER_GET (ic) &&
2617 !isOperandInFarSpace (IC_RESULT (ic)) &&
2618 !OP_SYMBOL (IC_LEFT (ic))->remat &&
2619 !IS_OP_RUONLY (IC_RESULT (ic)) &&
2620 getSize (aggrToPtr (operandType (IC_LEFT (ic)), FALSE)) > 1)
2622 packRegsForOneuse (ic, IC_LEFT (ic), ebp);
2625 /* if this is cast for intergral promotion then
2626 check if only use of the definition of the
2627 operand being casted/ if yes then replace
2628 the result of that arithmetic operation with
2629 this result and get rid of the cast */
2632 sym_link *fromType = operandType (IC_RIGHT (ic));
2633 sym_link *toType = operandType (IC_LEFT (ic));
2635 if (IS_INTEGRAL (fromType) && IS_INTEGRAL (toType) &&
2636 getSize (fromType) != getSize (toType) &&
2637 SPEC_USIGN (fromType) == SPEC_USIGN (toType))
2640 iCode *dic = packRegsForOneuse (ic, IC_RIGHT (ic), ebp);
2643 if (IS_ARITHMETIC_OP (dic))
2645 bitVectUnSetBit(OP_SYMBOL(IC_RESULT(dic))->defs,dic->key);
2646 IC_RESULT (dic) = IC_RESULT (ic);
2647 remiCodeFromeBBlock (ebp, ic);
2648 bitVectUnSetBit(OP_SYMBOL(IC_RESULT(ic))->defs,ic->key);
2649 hTabDeleteItem (&iCodehTab, ic->key, ic, DELETE_ITEM, NULL);
2650 OP_DEFS (IC_RESULT (dic)) = bitVectSetBit (OP_DEFS (IC_RESULT (dic)), dic->key);
2654 OP_SYMBOL (IC_RIGHT (ic))->ruonly = 0;
2660 /* if the type from and type to are the same
2661 then if this is the only use then packit */
2662 if (compareType (operandType (IC_RIGHT (ic)),
2663 operandType (IC_LEFT (ic))) == 1)
2665 iCode *dic = packRegsForOneuse (ic, IC_RIGHT (ic), ebp);
2668 bitVectUnSetBit(OP_SYMBOL(IC_RESULT(dic))->defs,dic->key);
2669 IC_RESULT (dic) = IC_RESULT (ic);
2670 remiCodeFromeBBlock (ebp, ic);
2671 bitVectUnSetBit(OP_SYMBOL(IC_RESULT(ic))->defs,ic->key);
2672 hTabDeleteItem (&iCodehTab, ic->key, ic, DELETE_ITEM, NULL);
2673 OP_DEFS (IC_RESULT (dic)) = bitVectSetBit (OP_DEFS (IC_RESULT (dic)), dic->key);
2681 iTempNN := (some variable in farspace) V1
2686 if (ic->op == IPUSH)
2688 packForPush (ic, ebp);
2692 /* pack registers for accumulator use, when the
2693 result of an arithmetic or bit wise operation
2694 has only one use, that use is immediately following
2695 the defintion and the using iCode has only one
2696 operand or has two operands but one is literal &
2697 the result of that operation is not on stack then
2698 we can leave the result of this operation in acc:b
2700 if ((IS_ARITHMETIC_OP (ic)
2701 || IS_CONDITIONAL(ic)
2702 || IS_BITWISE_OP (ic)
2703 || ic->op == LEFT_OP || ic->op == RIGHT_OP || ic->op == CALL
2704 || (ic->op == ADDRESS_OF && isOperandOnStack (IC_LEFT (ic)))
2706 IS_ITEMP (IC_RESULT (ic)) &&
2707 getSize (operandType (IC_RESULT (ic))) <= 2)
2709 packRegsForAccUse (ic);
2713 /*-----------------------------------------------------------------*/
2714 /* assignRegisters - assigns registers to each live range as need */
2715 /*-----------------------------------------------------------------*/
2717 mcs51_assignRegisters (eBBlock ** ebbs, int count)
2722 setToNull ((void *) &_G.funcrUsed);
2723 setToNull ((void *) &_G.totRegAssigned);
2724 mcs51_ptrRegReq = _G.stackExtend = _G.dataExtend = 0;
2727 /* change assignments this will remove some
2728 live ranges reducing some register pressure */
2729 for (i = 0; i < count; i++)
2730 packRegisters (ebbs[i]);
2732 if (options.dump_pack)
2733 dumpEbbsToFileExt (DUMP_PACK, ebbs, count);
2735 /* first determine for each live range the number of
2736 registers & the type of registers required for each */
2739 /* and serially allocate registers */
2740 serialRegAssign (ebbs, count);
2745 /* if stack was extended then tell the user */
2748 /* werror(W_TOOMANY_SPILS,"stack", */
2749 /* _G.stackExtend,currFunc->name,""); */
2755 /* werror(W_TOOMANY_SPILS,"data space", */
2756 /* _G.dataExtend,currFunc->name,""); */
2760 /* after that create the register mask
2761 for each of the instruction */
2762 createRegMask (ebbs, count);
2764 /* redo that offsets for stacked automatic variables */
2765 redoStackOffsets ();
2767 if (options.dump_rassgn)
2769 dumpEbbsToFileExt (DUMP_RASSGN, ebbs, count);
2770 dumpLiveRanges (DUMP_LRANGE, liveRanges);
2773 /* do the overlaysegment stuff SDCCmem.c */
2774 doOverlays (ebbs, count);
2776 /* now get back the chain */
2777 ic = iCodeLabelOptimize (iCodeFromeBBlock (ebbs, count));
2781 /* free up any _G.stackSpil locations allocated */
2782 applyToSet (_G.stackSpil, deallocStackSpil);
2784 setToNull ((void **) &_G.stackSpil);
2785 setToNull ((void **) &_G.spiltSet);
2786 /* mark all registers as free */