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 */
54 bitVect *allBitregs; /* all bit registers */
58 /* Shared with gen.c */
59 int mcs51_ptrRegReq; /* one byte pointer register required */
65 {REG_GPR, R2_IDX, REG_GPR, "r2", "ar2", "0", 2, 1},
66 {REG_GPR, R3_IDX, REG_GPR, "r3", "ar3", "0", 3, 1},
67 {REG_GPR, R4_IDX, REG_GPR, "r4", "ar4", "0", 4, 1},
68 {REG_GPR, R5_IDX, REG_GPR, "r5", "ar5", "0", 5, 1},
69 {REG_GPR, R6_IDX, REG_GPR, "r6", "ar6", "0", 6, 1},
70 {REG_GPR, R7_IDX, REG_GPR, "r7", "ar7", "0", 7, 1},
71 {REG_PTR, R0_IDX, REG_PTR, "r0", "ar0", "0", 0, 1},
72 {REG_PTR, R1_IDX, REG_PTR, "r1", "ar1", "0", 1, 1},
73 {REG_BIT, B0_IDX, REG_BIT, "b0", "b0", "bits", 0, 1},
74 {REG_BIT, B1_IDX, REG_BIT, "b1", "b1", "bits", 1, 1},
75 {REG_BIT, B2_IDX, REG_BIT, "b2", "b2", "bits", 2, 1},
76 {REG_BIT, B3_IDX, REG_BIT, "b3", "b3", "bits", 3, 1},
77 {REG_BIT, B4_IDX, REG_BIT, "b4", "b4", "bits", 4, 1},
78 {REG_BIT, B5_IDX, REG_BIT, "b5", "b5", "bits", 5, 1},
79 {REG_BIT, B6_IDX, REG_BIT, "b6", "b6", "bits", 6, 1},
80 {REG_BIT, B7_IDX, REG_BIT, "b7", "b7", "bits", 7, 1},
81 {REG_GPR, X8_IDX, REG_GPR, "x8", "x8", "xreg", 0, 1},
82 {REG_GPR, X9_IDX, REG_GPR, "x9", "x9", "xreg", 1, 1},
83 {REG_GPR, X10_IDX, REG_GPR, "x10", "x10", "xreg", 2, 1},
84 {REG_GPR, X11_IDX, REG_GPR, "x11", "x11", "xreg", 3, 1},
85 {REG_GPR, X12_IDX, REG_GPR, "x12", "x12", "xreg", 4, 1},
86 {REG_CND, CND_IDX, REG_CND, "C", "psw", "0xd0", 0, 1},
87 {0, DPL_IDX, 0, "dpl", "dpl", "0x82", 0, 0},
88 {0, DPH_IDX, 0, "dph", "dph", "0x83", 0, 0},
89 {0, B_IDX, 0, "b", "b", "0xf0", 0, 0},
90 {0, A_IDX, 0, "a", "acc", "0xe0", 0, 0},
93 static void spillThis (symbol *);
94 static void freeAllRegs ();
96 /*-----------------------------------------------------------------*/
97 /* allocReg - allocates register of given type */
98 /*-----------------------------------------------------------------*/
100 allocReg (short type)
104 for (i = 0; i < mcs51_nRegs; i++)
107 /* if type is given as 0 then any
108 free register will do */
112 regs8051[i].isFree = 0;
115 bitVectSetBit (currFunc->regsUsed, i);
118 /* other wise look for specific type
120 if (regs8051[i].isFree &&
121 regs8051[i].type == type)
123 regs8051[i].isFree = 0;
126 bitVectSetBit (currFunc->regsUsed, i);
133 /*-----------------------------------------------------------------*/
134 /* allocThisReg - allocates a particular register (if free) */
135 /*-----------------------------------------------------------------*/
137 allocThisReg (regs * reg)
144 currFunc->regsUsed = bitVectSetBit (currFunc->regsUsed, reg->rIdx);
150 /*-----------------------------------------------------------------*/
151 /* mcs51_regWithIdx - returns pointer to register with index number*/
152 /*-----------------------------------------------------------------*/
154 mcs51_regWithIdx (int idx)
158 for (i = 0; i < sizeof(regs8051)/sizeof(regs); i++)
159 if (regs8051[i].rIdx == idx)
162 werror (E_INTERNAL_ERROR, __FILE__, __LINE__,
163 "regWithIdx not found");
167 /*-----------------------------------------------------------------*/
168 /* freeReg - frees a register */
169 /*-----------------------------------------------------------------*/
175 werror (E_INTERNAL_ERROR, __FILE__, __LINE__,
176 "freeReg - Freeing NULL register");
184 /*-----------------------------------------------------------------*/
185 /* nFreeRegs - returns number of free registers */
186 /*-----------------------------------------------------------------*/
193 for (i = 0; i < mcs51_nRegs; i++)
194 if (regs8051[i].isFree && regs8051[i].type == type)
199 /*-----------------------------------------------------------------*/
200 /* nfreeRegsType - free registers with type */
201 /*-----------------------------------------------------------------*/
203 nfreeRegsType (int type)
208 if ((nfr = nFreeRegs (type)) == 0)
209 return nFreeRegs (REG_GPR);
212 return nFreeRegs (type);
215 /*-----------------------------------------------------------------*/
216 /* useReg - marks a register as used */
217 /*-----------------------------------------------------------------*/
224 /*-----------------------------------------------------------------*/
225 /* computeSpillable - given a point find the spillable live ranges */
226 /*-----------------------------------------------------------------*/
228 computeSpillable (iCode * ic)
232 /* spillable live ranges are those that are live at this
233 point . the following categories need to be subtracted
235 a) - those that are already spilt
236 b) - if being used by this one
237 c) - defined by this one */
239 spillable = bitVectCopy (ic->rlive);
241 bitVectCplAnd (spillable, _G.spiltSet); /* those already spilt */
243 bitVectCplAnd (spillable, ic->uses); /* used in this one */
244 bitVectUnSetBit (spillable, ic->defKey);
245 spillable = bitVectIntersect (spillable, _G.regAssigned);
250 /*-----------------------------------------------------------------*/
251 /* bitType - will return 1 if the symbol has type REG_BIT */
252 /*-----------------------------------------------------------------*/
254 bitType (symbol * sym, eBBlock * ebp, iCode * ic)
256 return (sym->regType == REG_BIT ? 1 : 0);
259 /*-----------------------------------------------------------------*/
260 /* noSpilLoc - return true if a variable has no spil location */
261 /*-----------------------------------------------------------------*/
263 noSpilLoc (symbol * sym, eBBlock * ebp, iCode * ic)
265 return (sym->usl.spillLoc ? 0 : 1);
268 /*-----------------------------------------------------------------*/
269 /* hasSpilLoc - will return 1 if the symbol has spil location */
270 /*-----------------------------------------------------------------*/
272 hasSpilLoc (symbol * sym, eBBlock * ebp, iCode * ic)
274 return (sym->usl.spillLoc ? 1 : 0);
277 /*-----------------------------------------------------------------*/
278 /* directSpilLoc - will return 1 if the spillocation is in direct */
279 /*-----------------------------------------------------------------*/
281 directSpilLoc (symbol * sym, eBBlock * ebp, iCode * ic)
283 if (sym->usl.spillLoc &&
284 (IN_DIRSPACE (SPEC_OCLS (sym->usl.spillLoc->etype))))
290 /*-----------------------------------------------------------------*/
291 /* hasSpilLocnoUptr - will return 1 if the symbol has spil location */
292 /* but is not used as a pointer */
293 /*-----------------------------------------------------------------*/
295 hasSpilLocnoUptr (symbol * sym, eBBlock * ebp, iCode * ic)
297 return ((sym->usl.spillLoc && !sym->uptr) ? 1 : 0);
300 /*-----------------------------------------------------------------*/
301 /* rematable - will return 1 if the remat flag is set */
302 /*-----------------------------------------------------------------*/
304 rematable (symbol * sym, eBBlock * ebp, iCode * ic)
309 /*-----------------------------------------------------------------*/
310 /* notUsedInRemaining - not used or defined in remain of the block */
311 /*-----------------------------------------------------------------*/
313 notUsedInRemaining (symbol * sym, eBBlock * ebp, iCode * ic)
315 return ((usedInRemaining (operandFromSymbol (sym), ic) ? 0 : 1) &&
316 allDefsOutOfRange (sym->defs, ebp->fSeq, ebp->lSeq));
319 /*-----------------------------------------------------------------*/
320 /* allLRs - return true for all */
321 /*-----------------------------------------------------------------*/
323 allLRs (symbol * sym, eBBlock * ebp, iCode * ic)
328 /*-----------------------------------------------------------------*/
329 /* liveRangesWith - applies function to a given set of live range */
330 /*-----------------------------------------------------------------*/
332 liveRangesWith (bitVect * lrs, int (func) (symbol *, eBBlock *, iCode *),
333 eBBlock * ebp, iCode * ic)
338 if (!lrs || !lrs->size)
341 for (i = 1; i < lrs->size; i++)
344 if (!bitVectBitValue (lrs, i))
347 /* if we don't find it in the live range
348 hash table we are in serious trouble */
349 if (!(sym = hTabItemWithKey (liveRanges, i)))
351 werror (E_INTERNAL_ERROR, __FILE__, __LINE__,
352 "liveRangesWith could not find liveRange");
356 if (func (sym, ebp, ic) && bitVectBitValue (_G.regAssigned, sym->key))
357 addSetHead (&rset, sym);
364 /*-----------------------------------------------------------------*/
365 /* leastUsedLR - given a set determines which is the least used */
366 /*-----------------------------------------------------------------*/
368 leastUsedLR (set * sset)
370 symbol *sym = NULL, *lsym = NULL;
372 sym = lsym = setFirstItem (sset);
377 for (; lsym; lsym = setNextItem (sset))
380 /* if usage is the same then prefer
381 to spill the smaller of the two */
382 if (lsym->used == sym->used)
383 if (getSize (lsym->type) < getSize (sym->type))
387 if (lsym->used < sym->used)
392 setToNull ((void *) &sset);
397 /*-----------------------------------------------------------------*/
398 /* noOverLap - will iterate through the list looking for over lap */
399 /*-----------------------------------------------------------------*/
401 noOverLap (set * itmpStack, symbol * fsym)
405 for (sym = setFirstItem (itmpStack); sym;
406 sym = setNextItem (itmpStack))
408 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 this then
467 no 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 spill 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 (SNPRINTF (slocBuffer, sizeof(slocBuffer),
514 "sloc%d", _G.slocNum++) >= sizeof (slocBuffer))
516 fprintf (stderr, "***Internal error: slocBuffer overflowed: %s:%d\n",
521 sloc = newiTemp (slocBuffer);
523 /* set the type to the spilling symbol */
524 sloc->type = copyLinkChain (sym->type);
525 sloc->etype = getSpec (sloc->type);
526 if (!IS_BIT (sloc->etype))
528 SPEC_SCLS (sloc->etype) = S_DATA;
530 SPEC_EXTR (sloc->etype) = 0;
531 SPEC_STAT (sloc->etype) = 0;
532 SPEC_VOLATILE(sloc->etype) = 0;
533 SPEC_ABSA(sloc->etype) = 0;
535 /* we don't allow it to be allocated`
536 onto the external stack since : so we
537 temporarily turn it off ; we also
538 turn off memory model to prevent
539 the spil from going to the external storage
542 useXstack = options.useXstack;
543 model = options.model;
544 /* noOverlay = options.noOverlay; */
545 /* options.noOverlay = 1; */
546 options.model = options.useXstack = 0;
550 options.useXstack = useXstack;
551 options.model = model;
552 /* options.noOverlay = noOverlay; */
553 sloc->isref = 1; /* to prevent compiler warning */
555 /* if it is on the stack then update the stack */
556 if (IN_STACK (sloc->etype))
558 currFunc->stack += getSize (sloc->type);
559 _G.stackExtend += getSize (sloc->type);
562 _G.dataExtend += getSize (sloc->type);
564 /* add it to the _G.stackSpil set */
565 addSetHead (&_G.stackSpil, sloc);
566 sym->usl.spillLoc = sloc;
569 /* add it to the set of itempStack set
570 of the spill location */
571 addSetHead (&sloc->usl.itmpStack, sym);
575 /*-----------------------------------------------------------------*/
576 /* isSpiltOnStack - returns true if the spil location is on stack */
577 /*-----------------------------------------------------------------*/
579 isSpiltOnStack (symbol * sym)
589 /* if (sym->_G.stackSpil) */
592 if (!sym->usl.spillLoc)
595 etype = getSpec (sym->usl.spillLoc->type);
596 if (IN_STACK (etype))
602 /*-----------------------------------------------------------------*/
603 /* spillThis - spils a specific operand */
604 /*-----------------------------------------------------------------*/
606 spillThis (symbol * sym)
609 /* if this is rematerializable or has a spillLocation
610 we are okay, else we need to create a spillLocation
612 if (!(sym->remat || sym->usl.spillLoc))
613 createStackSpil (sym);
615 /* mark it has spilt & put it in the spilt set */
616 sym->isspilt = sym->spillA = 1;
617 _G.spiltSet = bitVectSetBit (_G.spiltSet, sym->key);
619 bitVectUnSetBit (_G.regAssigned, sym->key);
620 bitVectUnSetBit (_G.totRegAssigned, sym->key);
622 for (i = 0; i < sym->nRegs; i++)
626 freeReg (sym->regs[i]);
630 /* if spilt on stack then free up r0 & r1
631 if they could have been assigned to some
633 if (!mcs51_ptrRegReq && isSpiltOnStack (sym))
636 spillLRWithPtrReg (sym);
639 if (sym->usl.spillLoc && !sym->remat)
640 sym->usl.spillLoc->allocreq++;
644 /*-----------------------------------------------------------------*/
645 /* selectSpil - select a iTemp to spil : rather a simple procedure */
646 /*-----------------------------------------------------------------*/
648 selectSpil (iCode * ic, eBBlock * ebp, symbol * forSym)
650 bitVect *lrcs = NULL;
654 /* get the spillable live ranges */
655 lrcs = computeSpillable (ic);
657 /* remove incompatible registers */
658 if ((forSym->regType == REG_PTR) || (forSym->regType == REG_GPR))
660 selectS = liveRangesWith (lrcs, bitType, ebp, ic);
662 for (sym = setFirstItem (selectS); sym; sym = setNextItem (selectS))
664 bitVectUnSetBit (lrcs, sym->key);
668 /* get all live ranges that are rematerializable */
669 if ((selectS = liveRangesWith (lrcs, rematable, ebp, ic)))
671 /* return the least used of these */
672 return leastUsedLR (selectS);
675 /* get live ranges with spillLocations in direct space */
676 if ((selectS = liveRangesWith (lrcs, directSpilLoc, ebp, ic)))
678 sym = leastUsedLR (selectS);
679 strncpyz (sym->rname,
680 sym->usl.spillLoc->rname[0] ?
681 sym->usl.spillLoc->rname : sym->usl.spillLoc->name,
684 /* mark it as allocation required */
685 sym->usl.spillLoc->allocreq++;
689 /* if the symbol is local to the block then */
690 if (forSym->liveTo < ebp->lSeq)
692 /* check if there are any live ranges allocated
693 to registers that are not used in this block */
694 if (!_G.blockSpil && (selectS = liveRangesWith (lrcs, notUsedInBlock, ebp, ic)))
696 sym = leastUsedLR (selectS);
697 /* if this is not rematerializable */
706 /* check if there are any live ranges that not
707 used in the remainder of the block */
709 !isiCodeInFunctionCall (ic) &&
710 (selectS = liveRangesWith (lrcs, notUsedInRemaining, ebp, ic)))
712 sym = leastUsedLR (selectS);
725 /* find live ranges with spillocation && not used as pointers */
726 if ((selectS = liveRangesWith (lrcs, hasSpilLocnoUptr, ebp, ic)))
728 sym = leastUsedLR (selectS);
729 /* mark this as allocation required */
730 sym->usl.spillLoc->allocreq++;
734 /* find live ranges with spillocation */
735 if ((selectS = liveRangesWith (lrcs, hasSpilLoc, ebp, ic)))
737 sym = leastUsedLR (selectS);
738 sym->usl.spillLoc->allocreq++;
742 /* couldn't find then we need to create a spil
743 location on the stack , for which one? the least
745 if ((selectS = liveRangesWith (lrcs, noSpilLoc, ebp, ic)))
747 /* return a created spil location */
748 sym = createStackSpil (leastUsedLR (selectS));
749 sym->usl.spillLoc->allocreq++;
753 /* this is an extreme situation we will spill
754 this one : happens very rarely but it does happen */
760 /*-----------------------------------------------------------------*/
761 /* spilSomething - spil some variable & mark registers as free */
762 /*-----------------------------------------------------------------*/
764 spilSomething (iCode * ic, eBBlock * ebp, symbol * forSym)
769 /* get something we can spil */
770 ssym = selectSpil (ic, ebp, forSym);
772 /* mark it as spilt */
773 ssym->isspilt = ssym->spillA = 1;
774 _G.spiltSet = bitVectSetBit (_G.spiltSet, ssym->key);
776 /* mark it as not register assigned &
777 take it away from the set */
778 bitVectUnSetBit (_G.regAssigned, ssym->key);
779 bitVectUnSetBit (_G.totRegAssigned, ssym->key);
781 /* mark the registers as free */
782 for (i = 0; i < ssym->nRegs; i++)
784 freeReg (ssym->regs[i]);
786 /* if spilt on stack then free up r0 & r1
787 if they could have been assigned to as gprs */
788 if (!mcs51_ptrRegReq && isSpiltOnStack (ssym))
791 spillLRWithPtrReg (ssym);
794 /* if this was a block level spil then insert push & pop
795 at the start & end of block respectively */
798 iCode *nic = newiCode (IPUSH, operandFromSymbol (ssym), NULL);
799 /* add push to the start of the block */
800 addiCodeToeBBlock (ebp, nic, (ebp->sch->op == LABEL ?
801 ebp->sch->next : ebp->sch));
802 nic = newiCode (IPOP, operandFromSymbol (ssym), NULL);
803 /* add pop to the end of the block */
804 addiCodeToeBBlock (ebp, nic, NULL);
807 /* if spilt because not used in the remainder of the
808 block then add a push before this instruction and
809 a pop at the end of the block */
810 if (ssym->remainSpil)
813 iCode *nic = newiCode (IPUSH, operandFromSymbol (ssym), NULL);
814 /* add push just before this instruction */
815 addiCodeToeBBlock (ebp, nic, ic);
817 nic = newiCode (IPOP, operandFromSymbol (ssym), NULL);
818 /* add pop to the end of the block */
819 addiCodeToeBBlock (ebp, nic, NULL);
828 /*-----------------------------------------------------------------*/
829 /* getRegPtr - will try for PTR if not a GPR type if not spil */
830 /*-----------------------------------------------------------------*/
832 getRegPtr (iCode * ic, eBBlock * ebp, symbol * sym)
838 /* try for a ptr type */
839 if ((reg = allocReg (REG_PTR)))
842 /* try for gpr type */
843 if ((reg = allocReg (REG_GPR)))
846 /* we have to spil */
847 if (!spilSomething (ic, ebp, sym))
850 /* make sure partially assigned registers aren't reused */
851 for (j=0; j<=sym->nRegs; j++)
853 sym->regs[j]->isFree = 0;
855 /* this looks like an infinite loop but
856 in really selectSpil will abort */
860 /*-----------------------------------------------------------------*/
861 /* getRegGpr - will try for GPR if not spil */
862 /*-----------------------------------------------------------------*/
864 getRegGpr (iCode * ic, eBBlock * ebp, symbol * sym)
870 /* try for gpr type */
871 if ((reg = allocReg (REG_GPR)))
874 if (!mcs51_ptrRegReq)
875 if ((reg = allocReg (REG_PTR)))
878 /* we have to spil */
879 if (!spilSomething (ic, ebp, sym))
882 /* make sure partially assigned registers aren't reused */
883 for (j=0; j<=sym->nRegs; j++)
885 sym->regs[j]->isFree = 0;
887 /* this looks like an infinite loop but
888 in really selectSpil will abort */
892 /*-----------------------------------------------------------------*/
893 /* getRegBit - will try for Bit if not spill this */
894 /*-----------------------------------------------------------------*/
895 static regs *getRegBit (symbol * sym)
899 /* try for a bit type */
900 if ((reg = allocReg (REG_BIT)))
907 /*-----------------------------------------------------------------*/
908 /* getRegPtrNoSpil - get it cannot be spilt */
909 /*-----------------------------------------------------------------*/
910 static regs *getRegPtrNoSpil()
914 /* try for a ptr type */
915 if ((reg = allocReg (REG_PTR)))
918 /* try for gpr type */
919 if ((reg = allocReg (REG_GPR)))
924 /* just to make the compiler happy */
928 /*-----------------------------------------------------------------*/
929 /* getRegGprNoSpil - get it cannot be spilt */
930 /*-----------------------------------------------------------------*/
931 static regs *getRegGprNoSpil()
935 if ((reg = allocReg (REG_GPR)))
938 if (!mcs51_ptrRegReq)
939 if ((reg = allocReg (REG_PTR)))
944 /* just to make the compiler happy */
948 /*-----------------------------------------------------------------*/
949 /* getRegBitNoSpil - get it cannot be spilt */
950 /*-----------------------------------------------------------------*/
951 static regs *getRegBitNoSpil()
955 /* try for a ptr type */
956 if ((reg = allocReg (REG_BIT)))
959 /* try for gpr type */
960 if ((reg = allocReg (REG_GPR)))
965 /* just to make the compiler happy */
969 /*-----------------------------------------------------------------*/
970 /* symHasReg - symbol has a given register */
971 /*-----------------------------------------------------------------*/
973 symHasReg (symbol * sym, regs * reg)
977 for (i = 0; i < sym->nRegs; i++)
978 if (sym->regs[i] == reg)
984 /*-----------------------------------------------------------------*/
985 /* updateRegUsage - update the registers in use at the start of */
987 /*-----------------------------------------------------------------*/
989 updateRegUsage (iCode * ic)
993 for (reg=0; reg<mcs51_nRegs; reg++)
995 if (regs8051[reg].isFree)
997 ic->riu &= ~(1<<regs8051[reg].offset);
1001 ic->riu |= (1<<regs8051[reg].offset);
1002 BitBankUsed |= (reg >= 8);
1007 /*-----------------------------------------------------------------*/
1008 /* deassignLRs - check the live to and if they have registers & are */
1009 /* not spilt then free up the registers */
1010 /*-----------------------------------------------------------------*/
1012 deassignLRs (iCode * ic, eBBlock * ebp)
1018 for (sym = hTabFirstItem (liveRanges, &k); sym;
1019 sym = hTabNextItem (liveRanges, &k))
1022 symbol *psym = NULL;
1023 /* if it does not end here */
1024 if (sym->liveTo > ic->seq)
1027 /* if it was spilt on stack then we can
1028 mark the stack spil location as free */
1033 sym->usl.spillLoc->isFree = 1;
1039 if (!bitVectBitValue (_G.regAssigned, sym->key))
1042 /* special case check if this is an IFX &
1043 the privious one was a pop and the
1044 previous one was not spilt then keep track
1046 if (ic->op == IFX && ic->prev &&
1047 ic->prev->op == IPOP &&
1048 !ic->prev->parmPush &&
1049 !OP_SYMBOL (IC_LEFT (ic->prev))->isspilt)
1050 psym = OP_SYMBOL (IC_LEFT (ic->prev));
1056 bitVectUnSetBit (_G.regAssigned, sym->key);
1058 /* if the result of this one needs registers
1059 and does not have it then assign it right
1061 if (IC_RESULT (ic) &&
1062 !(SKIP_IC2 (ic) || /* not a special icode */
1063 ic->op == JUMPTABLE ||
1068 POINTER_SET (ic)) &&
1069 (result = OP_SYMBOL (IC_RESULT (ic))) && /* has a result */
1070 result->liveTo > ic->seq && /* and will live beyond this */
1071 result->liveTo <= ebp->lSeq && /* does not go beyond this block */
1072 result->liveFrom == ic->seq && /* does not start before here */
1073 result->regType == sym->regType && /* same register types */
1074 result->nRegs && /* which needs registers */
1075 !result->isspilt && /* and does not already have them */
1077 !bitVectBitValue (_G.regAssigned, result->key) &&
1078 /* the number of free regs + number of regs in this LR
1079 can accomodate the what result Needs */
1080 ((nfreeRegsType (result->regType) +
1081 sym->nRegs) >= result->nRegs)
1085 for (i = 0; i < result->nRegs; i++)
1087 result->regs[i] = sym->regs[i];
1089 result->regs[i] = getRegGpr (ic, ebp, result);
1091 _G.regAssigned = bitVectSetBit (_G.regAssigned, result->key);
1092 _G.totRegAssigned = bitVectSetBit (_G.totRegAssigned, result->key);
1096 /* free the remaining */
1097 for (; i < sym->nRegs; i++)
1101 if (!symHasReg (psym, sym->regs[i]))
1102 freeReg (sym->regs[i]);
1105 freeReg (sym->regs[i]);
1112 /*-----------------------------------------------------------------*/
1113 /* reassignLR - reassign this to registers */
1114 /*-----------------------------------------------------------------*/
1116 reassignLR (operand * op)
1118 symbol *sym = OP_SYMBOL (op);
1121 /* not spilt any more */
1122 sym->isspilt = sym->spillA = sym->blockSpil = sym->remainSpil = 0;
1123 bitVectUnSetBit (_G.spiltSet, sym->key);
1125 _G.regAssigned = bitVectSetBit (_G.regAssigned, sym->key);
1126 _G.totRegAssigned = bitVectSetBit (_G.totRegAssigned, sym->key);
1130 for (i = 0; i < sym->nRegs; i++)
1131 sym->regs[i]->isFree = 0;
1134 /*-----------------------------------------------------------------*/
1135 /* willCauseSpill - determines if allocating will cause a spill */
1136 /*-----------------------------------------------------------------*/
1138 willCauseSpill (int nr, int rt)
1140 /* first check if there are any available registers
1141 of the type required */
1144 /* special case for pointer type
1145 if pointer type not avlb then
1146 check for type gpr */
1147 if (nFreeRegs (rt) >= nr)
1149 if (nFreeRegs (REG_GPR) >= nr)
1152 else if (rt == REG_BIT)
1154 if (nFreeRegs (rt) >= nr)
1159 if (mcs51_ptrRegReq)
1161 if (nFreeRegs (rt) >= nr)
1166 if (nFreeRegs (REG_PTR) +
1167 nFreeRegs (REG_GPR) >= nr)
1172 /* it will cause a spil */
1176 /*-----------------------------------------------------------------*/
1177 /* positionRegs - the allocator can allocate same registers to res- */
1178 /* ult and operand, if this happens make sure they are in the same */
1179 /* position as the operand otherwise chaos results */
1180 /*-----------------------------------------------------------------*/
1182 positionRegs (symbol * result, symbol * opsym)
1184 int count = min (result->nRegs, opsym->nRegs);
1185 int i, j = 0, shared = 0;
1188 /* if the result has been spilt then cannot share */
1193 /* first make sure that they actually share */
1194 for (i = 0; i < count; i++)
1196 for (j = 0; j < count; j++)
1198 if (result->regs[i] == opsym->regs[j] && i != j)
1208 regs *tmp = result->regs[i];
1209 result->regs[i] = result->regs[j];
1210 result->regs[j] = tmp;
1217 /*------------------------------------------------------------------*/
1218 /* verifyRegsAssigned - make sure an iTemp is properly initialized; */
1219 /* it should either have registers or have beed spilled. Otherwise, */
1220 /* there was an uninitialized variable, so just spill this to get */
1221 /* the operand in a valid state. */
1222 /*------------------------------------------------------------------*/
1224 verifyRegsAssigned (operand *op, iCode * ic)
1229 if (!IS_ITEMP (op)) return;
1231 sym = OP_SYMBOL (op);
1232 if (sym->isspilt) return;
1233 if (!sym->nRegs) return;
1234 if (sym->regs[0]) return;
1236 werrorfl (ic->filename, ic->lineno, W_LOCAL_NOINIT,
1237 sym->prereqv ? sym->prereqv->name : sym->name);
1242 /*-----------------------------------------------------------------*/
1243 /* serialRegAssign - serially allocate registers to the variables */
1244 /*-----------------------------------------------------------------*/
1246 serialRegAssign (eBBlock ** ebbs, int count)
1250 /* for all blocks */
1251 for (i = 0; i < count; i++)
1256 if (ebbs[i]->noPath &&
1257 (ebbs[i]->entryLabel != entryLabel &&
1258 ebbs[i]->entryLabel != returnLabel))
1261 /* for all instructions do */
1262 for (ic = ebbs[i]->sch; ic; ic = ic->next)
1266 /* if this is an ipop that means some live
1267 range will have to be assigned again */
1269 reassignLR (IC_LEFT (ic));
1271 /* if result is present && is a true symbol */
1272 if (IC_RESULT (ic) && ic->op != IFX &&
1273 IS_TRUE_SYMOP (IC_RESULT (ic)))
1274 OP_SYMBOL (IC_RESULT (ic))->allocreq++;
1276 /* take away registers from live
1277 ranges that end at this instruction */
1278 deassignLRs (ic, ebbs[i]);
1280 /* some don't need registers */
1281 if (SKIP_IC2 (ic) ||
1282 ic->op == JUMPTABLE ||
1286 (IC_RESULT (ic) && POINTER_SET (ic)))
1289 /* now we need to allocate registers
1290 only for the result */
1291 if (IC_RESULT (ic)) {
1292 symbol *sym = OP_SYMBOL (IC_RESULT (ic));
1298 /* Make sure any spill location is definitely allocated */
1299 if (sym->isspilt && !sym->remat && sym->usl.spillLoc &&
1300 !sym->usl.spillLoc->allocreq)
1302 sym->usl.spillLoc->allocreq++;
1305 /* if it does not need or is spilt
1306 or is already assigned to registers
1307 or will not live beyond this instructions */
1310 bitVectBitValue (_G.regAssigned, sym->key) ||
1311 sym->liveTo <= ic->seq)
1314 /* if some liverange has been spilt at the block level
1315 and this one live beyond this block then spil this
1317 if (_G.blockSpil && sym->liveTo > ebbs[i]->lSeq) {
1322 willCS = willCauseSpill (sym->nRegs, sym->regType);
1323 /* if this is a bit variable then don't use precious registers
1324 along with expensive bit-to-char conversions but just spill
1326 if (willCS && SPEC_NOUN(sym->etype) == V_BIT) {
1331 /* if trying to allocate this will cause
1332 a spill and there is nothing to spill
1333 or this one is rematerializable then
1335 spillable = computeSpillable (ic);
1336 if (sym->remat || (willCS && bitVectIsZero (spillable))) {
1341 /* If the live range preceeds the point of definition
1342 then ideally we must take into account registers that
1343 have been allocated after sym->liveFrom but freed
1344 before ic->seq. This is complicated, so spill this
1345 symbol instead and let fillGaps handle the allocation. */
1346 if (sym->liveFrom < ic->seq) {
1351 /* if it has a spillocation & is used less than
1352 all other live ranges then spill this */
1354 if (sym->usl.spillLoc) {
1355 symbol *leastUsed = leastUsedLR (liveRangesWith (spillable,
1356 allLRs, ebbs[i], ic));
1357 if (leastUsed && leastUsed->used > sym->used) {
1362 /* if none of the liveRanges have a spillLocation then better
1363 to spill this one than anything else already assigned to registers */
1364 if (liveRangesWith(spillable,noSpilLoc,ebbs[i],ic)) {
1365 /* if this is local to this block then we might find a block spil */
1366 if (!(sym->liveFrom >= ebbs[i]->fSeq && sym->liveTo <= ebbs[i]->lSeq)) {
1373 /* if we need ptr regs for the right side
1375 if (POINTER_GET (ic) && IS_SYMOP (IC_LEFT (ic))
1376 && getSize (OP_SYMBOL (IC_LEFT (ic))->type) <= (unsigned int) PTRSIZE) {
1380 if (IC_LEFT (ic) && IS_SYMOP (IC_LEFT (ic))
1381 && SPEC_OCLS(OP_SYMBOL (IC_LEFT (ic))->etype) == idata) {
1385 if (IC_RIGHT (ic) && IS_SYMOP (IC_RIGHT (ic))
1386 && SPEC_OCLS(OP_SYMBOL (IC_RIGHT (ic))->etype) == idata) {
1391 /* else we assign registers to it */
1392 _G.regAssigned = bitVectSetBit (_G.regAssigned, sym->key);
1393 _G.totRegAssigned = bitVectSetBit (_G.totRegAssigned, sym->key);
1395 for (j = 0; j < sym->nRegs; j++) {
1396 sym->regs[j] = NULL;
1397 if (sym->regType == REG_PTR)
1398 sym->regs[j] = getRegPtr (ic, ebbs[i], sym);
1399 else if (sym->regType == REG_BIT)
1400 sym->regs[j] = getRegBit (sym);
1403 if (ic->op == CAST && IS_SYMOP (IC_RIGHT (ic)))
1405 symbol * right = OP_SYMBOL (IC_RIGHT (ic));
1407 if (right->regs[j] && (right->regType != REG_BIT))
1408 sym->regs[j] = allocThisReg (right->regs[j]);
1411 sym->regs[j] = getRegGpr (ic, ebbs[i], sym);
1414 /* if the allocation failed which means
1415 this was spilt then break */
1419 for (i=0; i < sym->nRegs ; i++ )
1420 sym->regs[i] = NULL;
1425 if (!POINTER_SET(ic) && !POINTER_GET(ic)) {
1426 /* if it shares registers with operands make sure
1427 that they are in the same position */
1428 if (IC_LEFT (ic) && IS_SYMOP (IC_LEFT (ic)) &&
1429 OP_SYMBOL (IC_LEFT (ic))->nRegs) {
1430 positionRegs (OP_SYMBOL (IC_RESULT (ic)),
1431 OP_SYMBOL (IC_LEFT (ic)));
1433 /* do the same for the right operand */
1434 if (IC_RIGHT (ic) && IS_SYMOP (IC_RIGHT (ic)) &&
1435 OP_SYMBOL (IC_RIGHT (ic))->nRegs) {
1436 positionRegs (OP_SYMBOL (IC_RESULT (ic)),
1437 OP_SYMBOL (IC_RIGHT (ic)));
1450 /* Check for and fix any problems with uninitialized operands */
1451 for (i = 0; i < count; i++)
1455 if (ebbs[i]->noPath &&
1456 (ebbs[i]->entryLabel != entryLabel &&
1457 ebbs[i]->entryLabel != returnLabel))
1460 for (ic = ebbs[i]->sch; ic; ic = ic->next)
1467 verifyRegsAssigned (IC_COND (ic), ic);
1471 if (ic->op == JUMPTABLE)
1473 verifyRegsAssigned (IC_JTCOND (ic), ic);
1477 verifyRegsAssigned (IC_RESULT (ic), ic);
1478 verifyRegsAssigned (IC_LEFT (ic), ic);
1479 verifyRegsAssigned (IC_RIGHT (ic), ic);
1484 /*-----------------------------------------------------------------*/
1485 /* fillGaps - Try to fill in the Gaps left by Pass1 */
1486 /*-----------------------------------------------------------------*/
1487 static void fillGaps()
1494 if (getenv("DISABLE_FILL_GAPS")) return;
1496 /* look for liveranges that were spilt by the allocator */
1497 for (sym = hTabFirstItem(liveRanges,&key) ; sym ;
1498 sym = hTabNextItem(liveRanges,&key)) {
1503 if (!sym->spillA || !sym->clashes || sym->remat) continue ;
1505 /* find the liveRanges this one clashes with, that are
1506 still assigned to registers & mark the registers as used*/
1507 for ( i = 0 ; i < sym->clashes->size ; i ++) {
1511 if (bitVectBitValue(sym->clashes,i) == 0 || /* those that clash with this */
1512 bitVectBitValue(_G.totRegAssigned,i) == 0) /* and are still assigned to registers */
1515 clr = hTabItemWithKey(liveRanges,i);
1518 /* mark these registers as used */
1519 for (k = 0 ; k < clr->nRegs ; k++ )
1520 useReg(clr->regs[k]);
1523 if (willCauseSpill(sym->nRegs,sym->regType)) {
1524 /* NOPE :( clear all registers & and continue */
1530 for (i = 0 ; i < sym->defs->size ; i++ )
1532 if (bitVectBitValue(sym->defs,i))
1534 if (!(ic = hTabItemWithKey(iCodehTab,i)))
1541 D(printf("Attempting fillGaps on %s: [",sym->name));
1542 /* THERE IS HOPE !!!! */
1543 for (i=0; i < sym->nRegs ; i++ ) {
1544 if (sym->regType == REG_PTR)
1545 sym->regs[i] = getRegPtrNoSpil ();
1546 else if (sym->regType == REG_BIT)
1547 sym->regs[i] = getRegBitNoSpil ();
1550 sym->regs[i] = NULL;
1551 if (ic && ic->op == CAST && IS_SYMOP (IC_RIGHT (ic)))
1553 symbol * right = OP_SYMBOL (IC_RIGHT (ic));
1556 sym->regs[i] = allocThisReg (right->regs[i]);
1559 sym->regs[i] = getRegGprNoSpil ();
1561 D(printf("%s ", sym->regs[i]->name));
1565 /* For all its definitions check if the registers
1566 allocated needs positioning NOTE: we can position
1567 only ONCE if more than One positioning required
1569 We may need to perform the checks twice; once to
1570 position the registers as needed, the second to
1571 verify any register repositioning is still
1575 for (pass=0; pass<2; pass++) {
1576 D(printf(" checking definitions\n"));
1577 for (i = 0 ; i < sym->defs->size ; i++ ) {
1578 if (bitVectBitValue(sym->defs,i)) {
1579 if (!(ic = hTabItemWithKey(iCodehTab,i))) continue ;
1580 D(printf(" ic->seq = %d\n", ic->seq));
1581 if (SKIP_IC(ic)) continue;
1582 assert(isSymbolEqual(sym,OP_SYMBOL(IC_RESULT(ic)))); /* just making sure */
1583 /* if left is assigned to registers */
1584 if (IS_SYMOP(IC_LEFT(ic)))
1586 D(printf(" left = "));
1587 D(printOperand(IC_LEFT(ic),NULL));
1589 if (IS_SYMOP(IC_LEFT(ic)) &&
1590 bitVectBitValue(_G.totRegAssigned,OP_SYMBOL(IC_LEFT(ic))->key)) {
1591 pdone += (positionRegs(sym,OP_SYMBOL(IC_LEFT(ic)))>0);
1593 if (IS_SYMOP(IC_RIGHT(ic)))
1595 D(printf(" right = "));
1596 D(printOperand(IC_RIGHT(ic),NULL));
1598 if (IS_SYMOP(IC_RIGHT(ic)) &&
1599 bitVectBitValue(_G.totRegAssigned,OP_SYMBOL(IC_RIGHT(ic))->key)) {
1600 pdone += (positionRegs(sym,OP_SYMBOL(IC_RIGHT(ic)))>0);
1602 D(printf(" pdone = %d\n", pdone));
1603 if (pdone > 1) break;
1606 D(printf(" checking uses\n"));
1607 for (i = 0 ; i < sym->uses->size ; i++ ) {
1608 if (bitVectBitValue(sym->uses,i)) {
1610 if (!(ic = hTabItemWithKey(iCodehTab,i))) continue ;
1611 D(printf(" ic->seq = %d\n", ic->seq));
1612 if (SKIP_IC(ic)) continue;
1613 if (POINTER_SET(ic) || POINTER_GET(ic)) continue ;
1615 /* if result is assigned to registers */
1616 if (IS_SYMOP(IC_RESULT(ic)))
1618 D(printf(" result = "));
1619 D(printOperand(IC_RESULT(ic),NULL));
1621 if (IS_SYMOP(IC_RESULT(ic)) &&
1622 bitVectBitValue(_G.totRegAssigned,OP_SYMBOL(IC_RESULT(ic))->key)) {
1623 pdone += (positionRegs(sym,OP_SYMBOL(IC_RESULT(ic)))>0);
1625 D(printf(" pdone = %d\n", pdone));
1626 if (pdone > 1) break;
1629 if (pdone == 0) break; /* second pass only if regs repositioned */
1630 if (pdone > 1) break;
1632 D(printf(" sym->regs = ["));
1633 for (i=0; i < sym->nRegs ; i++ )
1634 D(printf("%s ", sym->regs[i]->name));
1636 /* had to position more than once GIVE UP */
1638 /* UNDO all the changes we made to try this */
1640 for (i=0; i < sym->nRegs ; i++ ) {
1641 sym->regs[i] = NULL;
1644 D(printf ("Fill Gap gave up due to positioning for %s in function %s\n",sym->name, currFunc ? currFunc->name : "UNKNOWN"));
1647 D(printf ("FILLED GAP for %s in function %s\n",sym->name, currFunc ? currFunc->name : "UNKNOWN"));
1649 _G.totRegAssigned = bitVectSetBit(_G.totRegAssigned,sym->key);
1650 sym->isspilt = sym->spillA = 0 ;
1651 sym->usl.spillLoc->allocreq--;
1656 /*-----------------------------------------------------------------*/
1657 /* findAllBitregs :- returns bit vector of all bit registers */
1658 /*-----------------------------------------------------------------*/
1660 findAllBitregs (void)
1662 bitVect *rmask = newBitVect (mcs51_nRegs);
1665 for (j = 0; j < mcs51_nRegs; j++)
1667 if (regs8051[j].type == REG_BIT)
1668 rmask = bitVectSetBit (rmask, regs8051[j].rIdx);
1674 /*-----------------------------------------------------------------*/
1675 /* mcs51_allBitregs :- returns bit vector of all bit registers */
1676 /*-----------------------------------------------------------------*/
1678 mcs51_allBitregs (void)
1680 return _G.allBitregs;
1683 /*-----------------------------------------------------------------*/
1684 /* rUmaskForOp :- returns register mask for an operand */
1685 /*-----------------------------------------------------------------*/
1687 mcs51_rUmaskForOp (operand * op)
1693 /* only temporaries are assigned registers */
1697 sym = OP_SYMBOL (op);
1699 /* if spilt or no registers assigned to it
1701 if (sym->isspilt || !sym->nRegs)
1704 rumask = newBitVect (mcs51_nRegs);
1706 for (j = 0; j < sym->nRegs; j++)
1708 if (sym->regs[j]) /* EEP - debug */
1709 rumask = bitVectSetBit (rumask, sym->regs[j]->rIdx);
1715 /*-----------------------------------------------------------------*/
1716 /* regsUsedIniCode :- returns bit vector of registers used in iCode */
1717 /*-----------------------------------------------------------------*/
1719 regsUsedIniCode (iCode * ic)
1721 bitVect *rmask = newBitVect (mcs51_nRegs);
1723 /* do the special cases first */
1726 rmask = bitVectUnion (rmask,
1727 mcs51_rUmaskForOp (IC_COND (ic)));
1731 /* for the jumptable */
1732 if (ic->op == JUMPTABLE)
1734 rmask = bitVectUnion (rmask,
1735 mcs51_rUmaskForOp (IC_JTCOND (ic)));
1740 /* of all other cases */
1742 rmask = bitVectUnion (rmask,
1743 mcs51_rUmaskForOp (IC_LEFT (ic)));
1747 rmask = bitVectUnion (rmask,
1748 mcs51_rUmaskForOp (IC_RIGHT (ic)));
1751 rmask = bitVectUnion (rmask,
1752 mcs51_rUmaskForOp (IC_RESULT (ic)));
1758 /*-----------------------------------------------------------------*/
1759 /* createRegMask - for each instruction will determine the regsUsed */
1760 /*-----------------------------------------------------------------*/
1762 createRegMask (eBBlock ** ebbs, int count)
1766 /* for all blocks */
1767 for (i = 0; i < count; i++)
1771 if (ebbs[i]->noPath &&
1772 (ebbs[i]->entryLabel != entryLabel &&
1773 ebbs[i]->entryLabel != returnLabel))
1776 /* for all instructions */
1777 for (ic = ebbs[i]->sch; ic; ic = ic->next)
1782 if (SKIP_IC2 (ic) || !ic->rlive)
1785 /* first mark the registers used in this
1787 ic->rUsed = regsUsedIniCode (ic);
1788 _G.funcrUsed = bitVectUnion (_G.funcrUsed, ic->rUsed);
1790 /* now create the register mask for those
1791 registers that are in use : this is a
1792 super set of ic->rUsed */
1793 ic->rMask = newBitVect (mcs51_nRegs + 1);
1795 /* for all live Ranges alive at this point */
1796 for (j = 1; j < ic->rlive->size; j++)
1801 /* if not alive then continue */
1802 if (!bitVectBitValue (ic->rlive, j))
1805 /* find the live range we are interested in */
1806 if (!(sym = hTabItemWithKey (liveRanges, j)))
1808 werror (E_INTERNAL_ERROR, __FILE__, __LINE__,
1809 "createRegMask cannot find live range");
1810 fprintf(stderr, "\tmissing live range: key=%d\n", j);
1814 /* if no register assigned to it */
1815 if (!sym->nRegs || sym->isspilt)
1818 /* for all the registers allocated to it */
1819 for (k = 0; k < sym->nRegs; k++)
1822 bitVectSetBit (ic->rMask, sym->regs[k]->rIdx);
1828 /*-----------------------------------------------------------------*/
1829 /* rematStr - returns the rematerialized string for a remat var */
1830 /*-----------------------------------------------------------------*/
1832 rematStr (symbol * sym)
1834 iCode *ic = sym->rematiCode;
1839 /* if plus adjust offset to right hand side */
1842 offset += (int) operandLitValue (IC_RIGHT (ic));
1843 ic = OP_SYMBOL (IC_LEFT (ic))->rematiCode;
1847 /* if minus adjust offset to right hand side */
1850 offset -= (int) operandLitValue (IC_RIGHT (ic));
1851 ic = OP_SYMBOL (IC_LEFT (ic))->rematiCode;
1855 /* cast then continue */
1856 if (IS_CAST_ICODE(ic)) {
1857 ic = OP_SYMBOL (IC_RIGHT (ic))->rematiCode;
1860 /* we reached the end */
1866 SNPRINTF (buffer, sizeof(buffer),
1868 OP_SYMBOL (IC_LEFT (ic))->rname,
1869 offset >= 0 ? '+' : '-',
1870 abs (offset) & 0xffff);
1874 strncpyz (buffer, OP_SYMBOL (IC_LEFT (ic))->rname, sizeof(buffer));
1879 /*-----------------------------------------------------------------*/
1880 /* regTypeNum - computes the type & number of registers required */
1881 /*-----------------------------------------------------------------*/
1883 regTypeNum (eBBlock *ebbs)
1889 /* for each live range do */
1890 for (sym = hTabFirstItem (liveRanges, &k); sym;
1891 sym = hTabNextItem (liveRanges, &k))
1894 /* if used zero times then no registers needed */
1895 if ((sym->liveTo - sym->liveFrom) == 0)
1899 /* if the live range is a temporary */
1903 /* if the type is marked as a conditional */
1904 if (sym->regType == REG_CND)
1907 /* if used in return only then we don't
1909 if (sym->ruonly || sym->accuse)
1911 if (IS_AGGREGATE (sym->type) || sym->isptr)
1912 sym->type = aggrToPtr (sym->type, FALSE);
1916 /* if the symbol has only one definition &
1917 that definition is a get_pointer */
1918 if (bitVectnBitsOn (sym->defs) == 1 &&
1919 (ic = hTabItemWithKey (iCodehTab,
1920 bitVectFirstBit (sym->defs))) &&
1922 !IS_BITVAR (sym->etype) &&
1923 (aggrToPtrDclType (operandType (IC_LEFT (ic)), FALSE) == POINTER))
1926 if (ptrPseudoSymSafe (sym, ic))
1928 ptrPseudoSymConvert (sym, ic, rematStr (OP_SYMBOL (IC_LEFT (ic))));
1932 /* if in data space or idata space then try to
1933 allocate pointer register */
1937 /* if not then we require registers */
1938 sym->nRegs = ((IS_AGGREGATE (sym->type) || sym->isptr) ?
1939 getSize (sym->type = aggrToPtr (sym->type, FALSE)) :
1940 getSize (sym->type));
1944 fprintf (stderr, "allocated more than 4 or 0 registers for type ");
1945 printTypeChain (sym->type, stderr);
1946 fprintf (stderr, "\n");
1949 /* determine the type of register required */
1950 if (sym->nRegs == 1 && IS_PTR (sym->type) && sym->uptr)
1951 sym->regType = REG_PTR;
1952 else if (IS_BIT(sym->type))
1953 sym->regType = REG_BIT;
1955 sym->regType = REG_GPR;
1958 /* for the first run we don't provide */
1959 /* registers for true symbols we will */
1960 /* see how things go */
1966 /*-----------------------------------------------------------------*/
1967 /* freeAllRegs - mark all registers as free */
1968 /*-----------------------------------------------------------------*/
1974 for (i = 0; i < mcs51_nRegs; i++)
1975 regs8051[i].isFree = 1;
1978 /*-----------------------------------------------------------------*/
1979 /* deallocStackSpil - this will set the stack pointer back */
1980 /*-----------------------------------------------------------------*/
1982 DEFSETFUNC (deallocStackSpil)
1990 /*-----------------------------------------------------------------*/
1991 /* farSpacePackable - returns the packable icode for far variables */
1992 /*-----------------------------------------------------------------*/
1994 farSpacePackable (iCode * ic)
1998 /* go thru till we find a definition for the
1999 symbol on the right */
2000 for (dic = ic->prev; dic; dic = dic->prev)
2002 /* if the definition is a call then no */
2003 if ((dic->op == CALL || dic->op == PCALL) &&
2004 IC_RESULT (dic)->key == IC_RIGHT (ic)->key)
2009 /* if shift by unknown amount then not */
2010 if ((dic->op == LEFT_OP || dic->op == RIGHT_OP) &&
2011 IC_RESULT (dic)->key == IC_RIGHT (ic)->key)
2014 /* if pointer get and size > 1 */
2015 if (POINTER_GET (dic) &&
2016 getSize (aggrToPtr (operandType (IC_LEFT (dic)), FALSE)) > 1)
2019 if (POINTER_SET (dic) &&
2020 getSize (aggrToPtr (operandType (IC_RESULT (dic)), FALSE)) > 1)
2025 if (IC_COND (dic) &&
2026 IS_TRUE_SYMOP (IC_COND (dic)) &&
2027 isOperandInFarSpace (IC_COND (dic)))
2030 else if (dic->op == JUMPTABLE)
2032 if (IC_JTCOND (dic) &&
2033 IS_TRUE_SYMOP (IC_JTCOND (dic)) &&
2034 isOperandInFarSpace (IC_JTCOND (dic)))
2039 /* if any tree is a true symbol in far space */
2040 if (IC_RESULT (dic) &&
2041 IS_TRUE_SYMOP (IC_RESULT (dic)) &&
2042 isOperandInFarSpace (IC_RESULT (dic)))
2045 if (IC_RIGHT (dic) &&
2046 IS_TRUE_SYMOP (IC_RIGHT (dic)) &&
2047 isOperandInFarSpace (IC_RIGHT (dic)) &&
2048 !isOperandEqual (IC_RIGHT (dic), IC_RESULT (ic)))
2051 if (IC_LEFT (dic) &&
2052 IS_TRUE_SYMOP (IC_LEFT (dic)) &&
2053 isOperandInFarSpace (IC_LEFT (dic)) &&
2054 !isOperandEqual (IC_LEFT (dic), IC_RESULT (ic)))
2058 if (isOperandEqual (IC_RIGHT (ic), IC_RESULT (dic)))
2060 if ((dic->op == LEFT_OP ||
2061 dic->op == RIGHT_OP ||
2063 IS_OP_LITERAL (IC_RIGHT (dic)))
2073 /*-----------------------------------------------------------------*/
2074 /* packRegsForAssign - register reduction for assignment */
2075 /*-----------------------------------------------------------------*/
2077 packRegsForAssign (iCode * ic, eBBlock * ebp)
2081 if (!IS_ITEMP (IC_RIGHT (ic)) ||
2082 OP_SYMBOL (IC_RIGHT (ic))->isind ||
2083 OP_LIVETO (IC_RIGHT (ic)) > ic->seq)
2088 /* if the true symbol is defined in far space or on stack
2089 then we should not since this will increase register pressure */
2090 if (isOperandInFarSpace(IC_RESULT(ic)) && !farSpacePackable(ic)) {
2094 /* find the definition of iTempNN scanning backwards if we find a
2095 a use of the true symbol in before we find the definition then
2097 for (dic = ic->prev; dic; dic = dic->prev)
2099 int crossedCall = 0;
2101 /* We can pack across a function call only if it's a local */
2102 /* variable or our parameter. Never pack global variables */
2103 /* or parameters to a function we call. */
2104 if ((dic->op == CALL || dic->op == PCALL))
2106 if (!OP_SYMBOL (IC_RESULT (ic))->ismyparm
2107 && !OP_SYMBOL (IC_RESULT (ic))->islocal)
2113 /* Don't move an assignment out of a critical block */
2114 if (dic->op == CRITICAL)
2125 if (IS_SYMOP (IC_COND (dic)) &&
2126 (IC_COND (dic)->key == IC_RESULT (ic)->key ||
2127 IC_COND (dic)->key == IC_RIGHT (ic)->key))
2135 if (IS_TRUE_SYMOP (IC_RESULT (dic)) &&
2136 IS_OP_VOLATILE (IC_RESULT (dic)))
2142 if (IS_SYMOP (IC_RESULT (dic)) &&
2143 IC_RESULT (dic)->key == IC_RIGHT (ic)->key)
2145 if (POINTER_SET (dic))
2151 if (IS_SYMOP (IC_RIGHT (dic)) &&
2152 (IC_RIGHT (dic)->key == IC_RESULT (ic)->key ||
2153 IC_RIGHT (dic)->key == IC_RIGHT (ic)->key))
2159 if (IS_SYMOP (IC_LEFT (dic)) &&
2160 (IC_LEFT (dic)->key == IC_RESULT (ic)->key ||
2161 IC_LEFT (dic)->key == IC_RIGHT (ic)->key))
2167 if (IS_SYMOP (IC_RESULT (dic)) &&
2168 IC_RESULT (dic)->key == IC_RESULT (ic)->key)
2184 return 0; /* did not find */
2186 /* if assignment then check that right is not a bit */
2187 if (ASSIGNMENT (ic) && !POINTER_SET (ic))
2189 sym_link *etype = operandType (IC_RESULT (dic));
2190 if (IS_BITFIELD (etype))
2192 /* if result is a bit too then it's ok */
2193 etype = operandType (IC_RESULT (ic));
2194 if (!IS_BITFIELD (etype))
2201 /* if the result is on stack or iaccess then it must be
2202 the same atleast one of the operands */
2203 if (OP_SYMBOL (IC_RESULT (ic))->onStack ||
2204 OP_SYMBOL (IC_RESULT (ic))->iaccess)
2207 /* the operation has only one symbol
2208 operator then we can pack */
2209 if ((IC_LEFT (dic) && !IS_SYMOP (IC_LEFT (dic))) ||
2210 (IC_RIGHT (dic) && !IS_SYMOP (IC_RIGHT (dic))))
2213 if (!((IC_LEFT (dic) &&
2214 IC_RESULT (ic)->key == IC_LEFT (dic)->key) ||
2216 IC_RESULT (ic)->key == IC_RIGHT (dic)->key)))
2220 /* found the definition */
2221 /* replace the result with the result of */
2222 /* this assignment and remove this assignment */
2223 bitVectUnSetBit(OP_SYMBOL(IC_RESULT(dic))->defs,dic->key);
2224 ReplaceOpWithCheaperOp(&IC_RESULT (dic), IC_RESULT (ic));
2226 if (IS_ITEMP (IC_RESULT (dic)) && OP_SYMBOL (IC_RESULT (dic))->liveFrom > dic->seq)
2228 OP_SYMBOL (IC_RESULT (dic))->liveFrom = dic->seq;
2230 // TODO: and the otherway around?
2232 /* delete from liverange table also
2233 delete from all the points inbetween and the new
2235 for (sic = dic; sic != ic; sic = sic->next)
2237 bitVectUnSetBit (sic->rlive, IC_RESULT (ic)->key);
2238 if (IS_ITEMP (IC_RESULT (dic)))
2239 bitVectSetBit (sic->rlive, IC_RESULT (dic)->key);
2242 remiCodeFromeBBlock (ebp, ic);
2243 bitVectUnSetBit(OP_SYMBOL(IC_RESULT(ic))->defs,ic->key);
2244 hTabDeleteItem (&iCodehTab, ic->key, ic, DELETE_ITEM, NULL);
2245 OP_DEFS(IC_RESULT (dic))=bitVectSetBit (OP_DEFS (IC_RESULT (dic)), dic->key);
2249 /*------------------------------------------------------------------*/
2250 /* findAssignToSym : scanning backwards looks for first assig found */
2251 /*------------------------------------------------------------------*/
2253 findAssignToSym (operand * op, iCode * ic)
2257 /* This routine is used to find sequences like
2259 ...; (intervening ops don't use iTempAA or modify FOO)
2260 blah = blah + iTempAA;
2262 and eliminate the use of iTempAA, freeing up its register for
2266 for (dic = ic->prev; dic; dic = dic->prev)
2269 /* if definition by assignment */
2270 if (dic->op == '=' &&
2271 !POINTER_SET (dic) &&
2272 IC_RESULT (dic)->key == op->key
2273 /* && IS_TRUE_SYMOP(IC_RIGHT(dic)) */
2275 break; /* found where this temp was defined */
2277 /* if we find an usage then we cannot delete it */
2281 if (IC_COND (dic) && IC_COND (dic)->key == op->key)
2284 else if (dic->op == JUMPTABLE)
2286 if (IC_JTCOND (dic) && IC_JTCOND (dic)->key == op->key)
2291 if (IC_LEFT (dic) && IC_LEFT (dic)->key == op->key)
2294 if (IC_RIGHT (dic) && IC_RIGHT (dic)->key == op->key)
2297 if (POINTER_SET (dic) && IC_RESULT (dic)->key == op->key)
2303 return NULL; /* didn't find any assignment to op */
2305 /* we are interested only if defined in far space */
2306 /* or in stack space in case of + & - */
2308 /* if assigned to a non-symbol then don't repack regs */
2309 if (!IS_SYMOP (IC_RIGHT (dic)))
2312 /* if the symbol is volatile then we should not */
2313 if (isOperandVolatile (IC_RIGHT (dic), TRUE))
2315 /* XXX TODO --- should we be passing FALSE to isOperandVolatile()?
2316 What does it mean for an iTemp to be volatile, anyway? Passing
2317 TRUE is more cautious but may prevent possible optimizations */
2319 /* if the symbol is in far space then we should not */
2320 if (isOperandInFarSpace (IC_RIGHT (dic)))
2323 /* for + & - operations make sure that
2324 if it is on the stack it is the same
2325 as one of the three operands */
2326 if ((ic->op == '+' || ic->op == '-') &&
2327 OP_SYMBOL (IC_RIGHT (dic))->onStack)
2330 if (IC_RESULT (ic)->key != IC_RIGHT (dic)->key &&
2331 IC_LEFT (ic)->key != IC_RIGHT (dic)->key &&
2332 IC_RIGHT (ic)->key != IC_RIGHT (dic)->key)
2336 /* now make sure that the right side of dic
2337 is not defined between ic & dic */
2340 iCode *sic = dic->next;
2342 for (; sic != ic; sic = sic->next)
2343 if (IC_RESULT (sic) &&
2344 IC_RESULT (sic)->key == IC_RIGHT (dic)->key)
2351 /*-----------------------------------------------------------------*/
2352 /* reassignAliasedSym - used by packRegsForSupport to replace */
2353 /* redundant iTemp with equivalent symbol */
2354 /*-----------------------------------------------------------------*/
2356 reassignAliasedSym (eBBlock *ebp, iCode *assignment, iCode *use, operand *op)
2359 unsigned oldSymKey, newSymKey;
2361 oldSymKey = op->key;
2362 newSymKey = IC_RIGHT(assignment)->key;
2364 /* only track live ranges of compiler-generated temporaries */
2365 if (!IS_ITEMP(IC_RIGHT(assignment)))
2368 /* update the live-value bitmaps */
2369 for (ic = assignment; ic != use; ic = ic->next) {
2370 bitVectUnSetBit (ic->rlive, oldSymKey);
2372 ic->rlive = bitVectSetBit (ic->rlive, newSymKey);
2375 /* update the sym of the used operand */
2376 OP_SYMBOL(op) = OP_SYMBOL(IC_RIGHT(assignment));
2377 op->key = OP_SYMBOL(op)->key;
2378 OP_SYMBOL(op)->accuse = 0;
2380 /* update the sym's liverange */
2381 if ( OP_LIVETO(op) < ic->seq )
2382 setToRange(op, ic->seq, FALSE);
2384 /* remove the assignment iCode now that its result is unused */
2385 remiCodeFromeBBlock (ebp, assignment);
2386 bitVectUnSetBit(OP_SYMBOL(IC_RESULT(assignment))->defs, assignment->key);
2387 hTabDeleteItem (&iCodehTab, assignment->key, assignment, DELETE_ITEM, NULL);
2391 /*-----------------------------------------------------------------*/
2392 /* packRegsForSupport :- reduce some registers for support calls */
2393 /*-----------------------------------------------------------------*/
2395 packRegsForSupport (iCode * ic, eBBlock * ebp)
2399 /* for the left & right operand :- look to see if the
2400 left was assigned a true symbol in far space in that
2401 case replace them */
2403 if (IS_ITEMP (IC_LEFT (ic)) &&
2404 OP_SYMBOL (IC_LEFT (ic))->liveTo <= ic->seq)
2406 dic = findAssignToSym (IC_LEFT (ic), ic);
2410 /* found it we need to remove it from the block */
2411 reassignAliasedSym (ebp, dic, ic, IC_LEFT(ic));
2416 /* do the same for the right operand */
2417 if (IS_ITEMP (IC_RIGHT (ic)) &&
2418 OP_SYMBOL (IC_RIGHT (ic))->liveTo <= ic->seq)
2420 iCode *dic = findAssignToSym (IC_RIGHT (ic), ic);
2424 /* if this is a subtraction & the result
2425 is a true symbol in far space then don't pack */
2426 if (ic->op == '-' && IS_TRUE_SYMOP (IC_RESULT (dic)))
2428 sym_link *etype = getSpec (operandType (IC_RESULT (dic)));
2429 if (IN_FARSPACE (SPEC_OCLS (etype)))
2432 /* found it we need to remove it from the
2434 reassignAliasedSym (ebp, dic, ic, IC_RIGHT(ic));
2443 #define IS_OP_RUONLY(x) (x && IS_SYMOP(x) && OP_SYMBOL(x)->ruonly)
2446 /*-----------------------------------------------------------------*/
2447 /* packRegsForOneuse : - will reduce some registers for single Use */
2448 /*-----------------------------------------------------------------*/
2450 packRegsForOneuse (iCode * ic, operand * op, eBBlock * ebp)
2454 /* if returning a literal then do nothing */
2458 /* if rematerializable or already return use then do nothing */
2459 if (OP_SYMBOL(op)->remat || OP_SYMBOL(op)->ruonly)
2462 /* only upto 2 bytes since we cannot predict
2463 the usage of b, & acc */
2464 if (getSize (operandType (op)) > (fReturnSizeMCS51 - 2))
2467 if (ic->op != RETURN &&
2469 !POINTER_SET (ic) &&
2473 if (ic->op == SEND && ic->argreg != 1) return NULL;
2475 /* this routine will mark the a symbol as used in one
2476 instruction use only && if the defintion is local
2477 (ie. within the basic block) && has only one definition &&
2478 that definition is either a return value from a
2479 function or does not contain any variables in
2481 if (bitVectnBitsOn (OP_USES (op)) > 1)
2484 /* if it has only one defintion */
2485 if (bitVectnBitsOn (OP_DEFS (op)) > 1)
2486 return NULL; /* has more than one definition */
2488 /* get that definition */
2490 hTabItemWithKey (iCodehTab,
2491 bitVectFirstBit (OP_DEFS (op)))))
2494 /* if that only usage is a cast */
2495 if (dic->op == CAST) {
2496 /* to a bigger type */
2497 if (getSize(OP_SYM_TYPE(IC_RESULT(dic))) >
2498 getSize(OP_SYM_TYPE(IC_RIGHT(dic)))) {
2499 /* than we can not, since we cannot predict the usage of b & acc */
2504 /* found the definition now check if it is local */
2505 if (dic->seq < ebp->fSeq ||
2506 dic->seq > ebp->lSeq)
2507 return NULL; /* non-local */
2509 /* now check if it is the return from
2511 if (dic->op == CALL || dic->op == PCALL)
2513 if (ic->op != SEND && ic->op != RETURN &&
2514 !POINTER_SET(ic) && !POINTER_GET(ic))
2516 OP_SYMBOL (op)->ruonly = 1;
2522 /* otherwise check that the definition does
2523 not contain any symbols in far space */
2524 if (isOperandInFarSpace (IC_LEFT (dic)) ||
2525 isOperandInFarSpace (IC_RIGHT (dic)) ||
2526 IS_OP_RUONLY (IC_LEFT (ic)) ||
2527 IS_OP_RUONLY (IC_RIGHT (ic)))
2532 /* if pointer set then make sure the pointer
2534 if (POINTER_SET (dic) &&
2535 !IS_DATA_PTR (aggrToPtr (operandType (IC_RESULT (dic)), FALSE)))
2538 if (POINTER_GET (dic) &&
2539 !IS_DATA_PTR (aggrToPtr (operandType (IC_LEFT (dic)), FALSE)))
2543 /* Make sure no overlapping liverange is already assigned to DPTR */
2544 if (OP_SYMBOL(op)->clashes)
2549 for (i = 0 ; i < OP_SYMBOL(op)->clashes->size ; i++ )
2551 if (bitVectBitValue(OP_SYMBOL(op)->clashes,i))
2553 sym = hTabItemWithKey(liveRanges,i);
2562 /* also make sure the intervenening instructions
2563 don't have any thing in far space */
2564 for (dic = dic->next; dic && dic != ic && sic != ic; dic = dic->next)
2567 /* if there is an intervening function call then no */
2568 if (dic->op == CALL || dic->op == PCALL)
2570 /* if pointer set then make sure the pointer
2572 if (POINTER_SET (dic) &&
2573 !IS_DATA_PTR (aggrToPtr (operandType (IC_RESULT (dic)), FALSE)))
2576 if (POINTER_GET (dic) &&
2577 !IS_DATA_PTR (aggrToPtr (operandType (IC_LEFT (dic)), FALSE)))
2580 /* if address of & the result is remat the okay */
2581 if (dic->op == ADDRESS_OF &&
2582 OP_SYMBOL (IC_RESULT (dic))->remat)
2585 /* if operand has size of three or more & this
2586 operation is a '*','/' or '%' then 'b' may
2588 if ((dic->op == '%' || dic->op == '/' || dic->op == '*') &&
2589 getSize (operandType (op)) >= 3)
2592 /* if left or right or result is in far space */
2593 if (isOperandInFarSpace (IC_LEFT (dic)) ||
2594 isOperandInFarSpace (IC_RIGHT (dic)) ||
2595 isOperandInFarSpace (IC_RESULT (dic)) ||
2596 IS_OP_RUONLY (IC_LEFT (dic)) ||
2597 IS_OP_RUONLY (IC_RIGHT (dic)) ||
2598 IS_OP_RUONLY (IC_RESULT (dic)))
2602 /* if left or right or result is on stack */
2603 if (isOperandOnStack(IC_LEFT(dic)) ||
2604 isOperandOnStack(IC_RIGHT(dic)) ||
2605 isOperandOnStack(IC_RESULT(dic))) {
2610 OP_SYMBOL (op)->ruonly = 1;
2614 /*-----------------------------------------------------------------*/
2615 /* isBitwiseOptimizable - requirements of JEAN LOUIS VERN */
2616 /*-----------------------------------------------------------------*/
2618 isBitwiseOptimizable (iCode * ic)
2620 sym_link *ltype = getSpec (operandType (IC_LEFT (ic)));
2621 sym_link *rtype = getSpec (operandType (IC_RIGHT (ic)));
2623 /* bitwise operations are considered optimizable
2624 under the following conditions (Jean-Louis VERN)
2636 if (IS_LITERAL(rtype) ||
2637 (IS_BITVAR (ltype) && IN_BITSPACE (SPEC_OCLS (ltype))))
2643 /*-----------------------------------------------------------------*/
2644 /* isCommutativeOp - tests whether this op cares what order its */
2645 /* operands are in */
2646 /*-----------------------------------------------------------------*/
2647 bool isCommutativeOp(unsigned int op)
2649 if (op == '+' || op == '*' || op == EQ_OP ||
2650 op == '^' || op == '|' || op == BITWISEAND)
2656 /*-----------------------------------------------------------------*/
2657 /* operandUsesAcc - determines whether the code generated for this */
2658 /* operand will have to use the accumulator */
2659 /*-----------------------------------------------------------------*/
2660 bool operandUsesAcc(operand *op)
2666 symbol *sym = OP_SYMBOL(op);
2670 return TRUE; /* duh! */
2672 if (IN_STACK(sym->etype) || sym->onStack ||
2673 (SPIL_LOC(op) && SPIL_LOC(op)->onStack))
2674 return TRUE; /* acc is used to calc stack offset */
2679 sym = SPIL_LOC(op); /* if spilled, look at spill location */
2681 return FALSE; /* more checks? */
2685 symspace = SPEC_OCLS(sym->etype);
2687 if (sym->iaccess && symspace->paged)
2688 return TRUE; /* must fetch paged indirect sym via accumulator */
2690 if (IN_BITSPACE(symspace))
2691 return TRUE; /* fetching bit vars uses the accumulator */
2693 if (IN_FARSPACE(symspace) || IN_CODESPACE(symspace))
2694 return TRUE; /* fetched via accumulator and dptr */
2700 /*-----------------------------------------------------------------*/
2701 /* packRegsForAccUse - pack registers for acc use */
2702 /*-----------------------------------------------------------------*/
2704 packRegsForAccUse (iCode * ic)
2708 /* if this is an aggregate, e.g. a one byte char array */
2709 if (IS_AGGREGATE(operandType(IC_RESULT(ic)))) {
2713 /* if we are calling a reentrant function that has stack parameters */
2714 if (ic->op == CALL &&
2715 IFFUNC_ISREENT(operandType(IC_LEFT(ic))) &&
2716 FUNC_HASSTACKPARM(operandType(IC_LEFT(ic))))
2719 if (ic->op == PCALL &&
2720 IFFUNC_ISREENT(operandType(IC_LEFT(ic))->next) &&
2721 FUNC_HASSTACKPARM(operandType(IC_LEFT(ic))->next))
2724 /* if + or - then it has to be one byte result */
2725 if ((ic->op == '+' || ic->op == '-')
2726 && getSize (operandType (IC_RESULT (ic))) > 1)
2729 /* if shift operation make sure right side is not a literal */
2730 if (ic->op == RIGHT_OP &&
2731 (isOperandLiteral (IC_RIGHT (ic)) ||
2732 getSize (operandType (IC_RESULT (ic))) > 1))
2735 if (ic->op == LEFT_OP &&
2736 (isOperandLiteral (IC_RIGHT (ic)) ||
2737 getSize (operandType (IC_RESULT (ic))) > 1))
2740 if (IS_BITWISE_OP (ic) &&
2741 getSize (operandType (IC_RESULT (ic))) > 1)
2745 /* has only one definition */
2746 if (bitVectnBitsOn (OP_DEFS (IC_RESULT (ic))) > 1)
2749 /* has only one use */
2750 if (bitVectnBitsOn (OP_USES (IC_RESULT (ic))) > 1)
2753 /* and the usage immediately follows this iCode */
2754 if (!(uic = hTabItemWithKey (iCodehTab,
2755 bitVectFirstBit (OP_USES (IC_RESULT (ic))))))
2758 if (ic->next != uic)
2761 /* if it is a conditional branch then we definitely can */
2765 if (uic->op == JUMPTABLE)
2768 if (POINTER_SET (uic) &&
2769 getSize (aggrToPtr (operandType (IC_RESULT (uic)), FALSE)) > 1)
2772 /* if the usage is not is an assignment
2773 or an arithmetic / bitwise / shift operation then not */
2774 if (uic->op != '=' &&
2775 !IS_ARITHMETIC_OP (uic) &&
2776 !IS_BITWISE_OP (uic) &&
2777 uic->op != LEFT_OP &&
2778 uic->op != RIGHT_OP)
2781 /* if used in ^ operation then make sure right is not a
2782 literal (WIML: Why is this?) */
2783 if (uic->op == '^' && isOperandLiteral (IC_RIGHT (uic)))
2786 /* if shift operation make sure right side is not a literal */
2787 /* WIML: Why is this? */
2788 if (uic->op == RIGHT_OP &&
2789 (isOperandLiteral (IC_RIGHT (uic)) ||
2790 getSize (operandType (IC_RESULT (uic))) > 1))
2792 if (uic->op == LEFT_OP &&
2793 (isOperandLiteral (IC_RIGHT (uic)) ||
2794 getSize (operandType (IC_RESULT (uic))) > 1))
2797 /* make sure that the result of this icode is not on the
2798 stack, since acc is used to compute stack offset */
2800 if (IS_TRUE_SYMOP (IC_RESULT (uic)) &&
2801 OP_SYMBOL (IC_RESULT (uic))->onStack)
2804 if (isOperandOnStack(IC_RESULT(uic)))
2808 /* if the usage has only one operand then we can */
2809 if (IC_LEFT (uic) == NULL ||
2810 IC_RIGHT (uic) == NULL)
2813 /* if the other operand uses the accumulator then we cannot */
2814 if ( (IC_LEFT(uic)->key == IC_RESULT(ic)->key &&
2815 operandUsesAcc(IC_RIGHT(uic))) ||
2816 (IC_RIGHT(uic)->key == IC_RESULT(ic)->key &&
2817 operandUsesAcc(IC_LEFT(uic))) )
2820 /* make sure this is on the left side if not commutative */
2821 /* except for '-', which has been written to be able to
2822 handle reversed operands */
2823 if (!(isCommutativeOp(ic->op) || ic->op == '-') &&
2824 IC_LEFT (uic)->key != IC_RESULT (ic)->key)
2828 // this is too dangerous and need further restrictions
2831 /* if one of them is a literal then we can */
2832 if ((IC_LEFT (uic) && IS_OP_LITERAL (IC_LEFT (uic))) ||
2833 (IC_RIGHT (uic) && IS_OP_LITERAL (IC_RIGHT (uic))))
2835 OP_SYMBOL (IC_RESULT (ic))->accuse = 1;
2841 OP_SYMBOL (IC_RESULT (ic))->accuse = 1;
2845 /*-----------------------------------------------------------------*/
2846 /* packForPush - heuristics to reduce iCode for pushing */
2847 /*-----------------------------------------------------------------*/
2849 packForPush (iCode * ic, eBBlock ** ebpp, int blockno)
2853 struct eBBlock * ebp=ebpp[blockno];
2855 if (ic->op != IPUSH || !IS_ITEMP (IC_LEFT (ic)))
2858 /* must have only definition & one usage */
2859 if (bitVectnBitsOn (OP_DEFS (IC_LEFT (ic))) != 1 ||
2860 bitVectnBitsOn (OP_USES (IC_LEFT (ic))) != 1)
2863 /* find the definition */
2864 if (!(dic = hTabItemWithKey (iCodehTab,
2865 bitVectFirstBit (OP_DEFS (IC_LEFT (ic))))))
2868 if (dic->op != '=' || POINTER_SET (dic))
2871 if (dic->seq < ebp->fSeq) { // Evelyn did this
2873 for (i=0; i<blockno; i++) {
2874 if (dic->seq >= ebpp[i]->fSeq && dic->seq <= ebpp[i]->lSeq) {
2879 wassert (i!=blockno); // no way to recover from here
2882 if (IS_SYMOP(IC_RIGHT(dic))) {
2883 /* make sure the right side does not have any definitions
2885 dbv = OP_DEFS(IC_RIGHT(dic));
2886 for (lic = ic; lic && lic != dic ; lic = lic->prev) {
2887 if (bitVectBitValue(dbv,lic->key))
2890 /* make sure they have the same type */
2891 if (IS_SPEC(operandType(IC_LEFT(ic))))
2893 sym_link *itype=operandType(IC_LEFT(ic));
2894 sym_link *ditype=operandType(IC_RIGHT(dic));
2896 if (SPEC_USIGN(itype)!=SPEC_USIGN(ditype) ||
2897 SPEC_LONG(itype)!=SPEC_LONG(ditype))
2900 /* extend the live range of replaced operand if needed */
2901 if (OP_SYMBOL(IC_RIGHT(dic))->liveTo < ic->seq) {
2902 OP_SYMBOL(IC_RIGHT(dic))->liveTo = ic->seq;
2904 bitVectUnSetBit(OP_SYMBOL(IC_RESULT(dic))->defs,dic->key);
2907 /* we now we know that it has one & only one def & use
2908 and the that the definition is an assignment */
2909 ReplaceOpWithCheaperOp(&IC_LEFT (ic), IC_RIGHT (dic));
2910 remiCodeFromeBBlock (ebp, dic);
2911 hTabDeleteItem (&iCodehTab, dic->key, dic, DELETE_ITEM, NULL);
2914 /*-----------------------------------------------------------------*/
2915 /* packRegisters - does some transformations to reduce register */
2917 /*-----------------------------------------------------------------*/
2919 packRegisters (eBBlock ** ebpp, int blockno)
2923 eBBlock *ebp=ebpp[blockno];
2929 /* look for assignments of the form */
2930 /* iTempNN = TRueSym (someoperation) SomeOperand */
2932 /* TrueSym := iTempNN:1 */
2933 for (ic = ebp->sch; ic; ic = ic->next)
2935 /* find assignment of the form TrueSym := iTempNN:1 */
2936 if (ic->op == '=' && !POINTER_SET (ic))
2937 change += packRegsForAssign (ic, ebp);
2944 for (ic = ebp->sch; ic; ic = ic->next)
2946 /* Fix for bug #979599: */
2949 /* Look for two subsequent iCodes with */
2951 /* _c = iTemp & op; */
2952 /* and replace them by */
2955 if ((ic->op == BITWISEAND || ic->op == '|' || ic->op == '^') &&
2957 ic->prev->op == '=' &&
2958 IS_ITEMP (IC_LEFT (ic)) &&
2959 IC_LEFT (ic) == IC_RESULT (ic->prev) &&
2960 isOperandEqual (IC_RESULT(ic), IC_RIGHT(ic->prev)))
2962 iCode* ic_prev = ic->prev;
2963 symbol* prev_result_sym = OP_SYMBOL (IC_RESULT (ic_prev));
2965 ReplaceOpWithCheaperOp (&IC_LEFT (ic), IC_RESULT (ic));
2966 if (IC_RESULT (ic_prev) != IC_RIGHT (ic))
2968 bitVectUnSetBit (OP_USES (IC_RESULT (ic_prev)), ic->key);
2969 if (/*IS_ITEMP (IC_RESULT (ic_prev)) && */
2970 prev_result_sym->liveTo == ic->seq)
2972 prev_result_sym->liveTo = ic_prev->seq;
2975 bitVectSetBit (OP_USES (IC_RESULT (ic)), ic->key);
2977 bitVectSetBit (ic->rlive, IC_RESULT (ic)->key);
2979 if (bitVectIsZero (OP_USES (IC_RESULT (ic_prev))))
2981 bitVectUnSetBit (ic->rlive, IC_RESULT (ic)->key);
2982 bitVectUnSetBit (OP_DEFS (IC_RESULT (ic_prev)), ic_prev->key);
2983 remiCodeFromeBBlock (ebp, ic_prev);
2984 hTabDeleteItem (&iCodehTab, ic_prev->key, ic_prev, DELETE_ITEM, NULL);
2988 /* if this is an itemp & result of an address of a true sym
2989 then mark this as rematerialisable */
2990 if (ic->op == ADDRESS_OF &&
2991 IS_ITEMP (IC_RESULT (ic)) &&
2992 IS_TRUE_SYMOP (IC_LEFT (ic)) &&
2993 bitVectnBitsOn (OP_DEFS (IC_RESULT (ic))) == 1 &&
2994 !OP_SYMBOL (IC_LEFT (ic))->onStack)
2996 OP_SYMBOL (IC_RESULT (ic))->remat = 1;
2997 OP_SYMBOL (IC_RESULT (ic))->rematiCode = ic;
2998 OP_SYMBOL (IC_RESULT (ic))->usl.spillLoc = NULL;
3001 /* if straight assignment then carry remat flag if
3002 this is the only definition */
3003 if (ic->op == '=' &&
3004 !POINTER_SET (ic) &&
3005 IS_SYMOP (IC_RIGHT (ic)) &&
3006 OP_SYMBOL (IC_RIGHT (ic))->remat &&
3007 !IS_CAST_ICODE(OP_SYMBOL (IC_RIGHT (ic))->rematiCode) &&
3008 bitVectnBitsOn (OP_SYMBOL (IC_RESULT (ic))->defs) <= 1)
3010 OP_SYMBOL (IC_RESULT (ic))->remat =
3011 OP_SYMBOL (IC_RIGHT (ic))->remat;
3012 OP_SYMBOL (IC_RESULT (ic))->rematiCode =
3013 OP_SYMBOL (IC_RIGHT (ic))->rematiCode;
3016 /* if cast to a generic pointer & the pointer being
3017 cast is remat, then we can remat this cast as well */
3018 if (ic->op == CAST &&
3019 IS_SYMOP(IC_RIGHT(ic)) &&
3020 OP_SYMBOL(IC_RIGHT(ic))->remat &&
3021 bitVectnBitsOn (OP_DEFS (IC_RESULT (ic))) == 1)
3023 sym_link *to_type = operandType(IC_LEFT(ic));
3024 sym_link *from_type = operandType(IC_RIGHT(ic));
3025 if (IS_GENPTR(to_type) && IS_PTR(from_type))
3027 OP_SYMBOL (IC_RESULT (ic))->remat = 1;
3028 OP_SYMBOL (IC_RESULT (ic))->rematiCode = ic;
3029 OP_SYMBOL (IC_RESULT (ic))->usl.spillLoc = NULL;
3033 /* if this is a +/- operation with a rematerizable
3034 then mark this as rematerializable as well */
3035 if ((ic->op == '+' || ic->op == '-') &&
3036 (IS_SYMOP (IC_LEFT (ic)) &&
3037 IS_ITEMP (IC_RESULT (ic)) &&
3038 IS_OP_LITERAL (IC_RIGHT (ic))) &&
3039 OP_SYMBOL (IC_LEFT (ic))->remat &&
3040 (!IS_SYMOP (IC_RIGHT (ic)) || !IS_CAST_ICODE(OP_SYMBOL (IC_RIGHT (ic))->rematiCode)) &&
3041 bitVectnBitsOn (OP_DEFS (IC_RESULT (ic))) == 1)
3043 OP_SYMBOL (IC_RESULT (ic))->remat = 1;
3044 OP_SYMBOL (IC_RESULT (ic))->rematiCode = ic;
3045 OP_SYMBOL (IC_RESULT (ic))->usl.spillLoc = NULL;
3048 /* mark the pointer usages */
3049 if (POINTER_SET (ic))
3050 OP_SYMBOL (IC_RESULT (ic))->uptr = 1;
3052 if (POINTER_GET (ic) &&
3053 IS_SYMOP(IC_LEFT (ic)))
3054 OP_SYMBOL (IC_LEFT (ic))->uptr = 1;
3058 /* if we are using a symbol on the stack
3059 then we should say mcs51_ptrRegReq */
3060 if (options.useXstack && ic->parmPush
3061 && (ic->op == IPUSH || ic->op == IPOP))
3063 if (ic->op == IFX && IS_SYMOP (IC_COND (ic)))
3064 mcs51_ptrRegReq += ((OP_SYMBOL (IC_COND (ic))->onStack ||
3065 OP_SYMBOL (IC_COND (ic))->iaccess ||
3066 SPEC_OCLS(OP_SYMBOL (IC_COND (ic))->etype) == idata) ? 1 : 0);
3067 else if (ic->op == JUMPTABLE && IS_SYMOP (IC_JTCOND (ic)))
3068 mcs51_ptrRegReq += ((OP_SYMBOL (IC_JTCOND (ic))->onStack ||
3069 OP_SYMBOL (IC_JTCOND (ic))->iaccess ||
3070 SPEC_OCLS(OP_SYMBOL (IC_JTCOND (ic))->etype) == idata) ? 1 : 0);
3073 if (IS_SYMOP (IC_LEFT (ic)))
3074 mcs51_ptrRegReq += ((OP_SYMBOL (IC_LEFT (ic))->onStack ||
3075 OP_SYMBOL (IC_LEFT (ic))->iaccess ||
3076 SPEC_OCLS(OP_SYMBOL (IC_LEFT (ic))->etype) == idata) ? 1 : 0);
3077 if (IS_SYMOP (IC_RIGHT (ic)))
3078 mcs51_ptrRegReq += ((OP_SYMBOL (IC_RIGHT (ic))->onStack ||
3079 OP_SYMBOL (IC_RIGHT (ic))->iaccess ||
3080 SPEC_OCLS(OP_SYMBOL (IC_RIGHT (ic))->etype) == idata) ? 1 : 0);
3081 if (IS_SYMOP (IC_RESULT (ic)))
3082 mcs51_ptrRegReq += ((OP_SYMBOL (IC_RESULT (ic))->onStack ||
3083 OP_SYMBOL (IC_RESULT (ic))->iaccess ||
3084 SPEC_OCLS(OP_SYMBOL (IC_RESULT (ic))->etype) == idata) ? 1 : 0);
3085 if (POINTER_GET (ic) && IS_SYMOP (IC_LEFT (ic))
3086 && getSize (OP_SYMBOL (IC_LEFT (ic))->type) <= (unsigned int) PTRSIZE)
3088 if (POINTER_SET (ic) && IS_SYMOP (IC_RESULT (ic))
3089 && getSize (OP_SYMBOL (IC_RESULT (ic))->type) <= (unsigned int) PTRSIZE)
3094 /* if the condition of an if instruction
3095 is defined in the previous instruction and
3096 this is the only usage then
3097 mark the itemp as a conditional */
3098 if ((IS_CONDITIONAL (ic) ||
3099 (IS_BITWISE_OP(ic) && isBitwiseOptimizable (ic))) &&
3100 ic->next && ic->next->op == IFX &&
3101 bitVectnBitsOn (OP_USES(IC_RESULT(ic)))==1 &&
3102 isOperandEqual (IC_RESULT (ic), IC_COND (ic->next)) &&
3103 OP_SYMBOL (IC_RESULT (ic))->liveTo <= ic->next->seq)
3105 OP_SYMBOL (IC_RESULT (ic))->regType = REG_CND;
3109 /* if the condition of an if instruction
3110 is defined in the previous GET_POINTER instruction and
3111 this is the only usage then
3112 mark the itemp as accumulator use */
3113 if ((POINTER_GET (ic) && getSize (operandType (IC_RESULT (ic))) <=1) &&
3114 ic->next && ic->next->op == IFX &&
3115 bitVectnBitsOn (OP_USES(IC_RESULT(ic)))==1 &&
3116 isOperandEqual (IC_RESULT (ic), IC_COND (ic->next)) &&
3117 OP_SYMBOL (IC_RESULT (ic))->liveTo <= ic->next->seq)
3119 OP_SYMBOL (IC_RESULT (ic))->accuse = 1;
3123 /* reduce for support function calls */
3124 if (ic->supportRtn || ic->op == '+' || ic->op == '-')
3125 packRegsForSupport (ic, ebp);
3127 /* some cases the redundant moves can
3128 can be eliminated for return statements */
3129 if ((ic->op == RETURN || (ic->op == SEND && ic->argreg == 1)) &&
3130 !isOperandInFarSpace (IC_LEFT (ic)) &&
3131 options.model == MODEL_SMALL) {
3132 packRegsForOneuse (ic, IC_LEFT (ic), ebp);
3135 /* if pointer set & left has a size more than
3136 one and right is not in far space */
3137 if (POINTER_SET (ic) &&
3138 !isOperandInFarSpace (IC_RIGHT (ic)) &&
3139 !OP_SYMBOL (IC_RESULT (ic))->remat &&
3140 !IS_OP_RUONLY (IC_RIGHT (ic)) &&
3141 getSize (aggrToPtr (operandType (IC_RESULT (ic)), FALSE)) > 1)
3142 packRegsForOneuse (ic, IC_RESULT (ic), ebp);
3144 /* if pointer get */
3145 if (POINTER_GET (ic) &&
3146 IS_SYMOP (IC_LEFT (ic)) &&
3147 !isOperandInFarSpace (IC_RESULT (ic)) &&
3148 !OP_SYMBOL (IC_LEFT (ic))->remat &&
3149 !IS_OP_RUONLY (IC_RESULT (ic)) &&
3150 getSize (aggrToPtr (operandType (IC_LEFT (ic)), FALSE)) > 1)
3151 packRegsForOneuse (ic, IC_LEFT (ic), ebp);
3154 /* if this is a cast for intergral promotion then
3155 check if it's the only use of the definition of the
3156 operand being casted/ if yes then replace
3157 the result of that arithmetic operation with
3158 this result and get rid of the cast */
3161 sym_link *fromType = operandType (IC_RIGHT (ic));
3162 sym_link *toType = operandType (IC_LEFT (ic));
3164 if (IS_INTEGRAL (fromType) && IS_INTEGRAL (toType) &&
3165 getSize (fromType) != getSize (toType) &&
3166 SPEC_USIGN (fromType) == SPEC_USIGN (toType))
3169 iCode *dic = packRegsForOneuse (ic, IC_RIGHT (ic), ebp);
3172 if (IS_ARITHMETIC_OP (dic))
3174 bitVectUnSetBit(OP_SYMBOL(IC_RESULT(dic))->defs,dic->key);
3175 ReplaceOpWithCheaperOp(&IC_RESULT (dic), IC_RESULT (ic));
3176 remiCodeFromeBBlock (ebp, ic);
3177 bitVectUnSetBit(OP_SYMBOL(IC_RESULT(ic))->defs,ic->key);
3178 hTabDeleteItem (&iCodehTab, ic->key, ic, DELETE_ITEM, NULL);
3179 OP_DEFS(IC_RESULT (dic))=bitVectSetBit (OP_DEFS (IC_RESULT (dic)), dic->key);
3183 OP_SYMBOL (IC_RIGHT (ic))->ruonly = 0;
3189 /* if the type from and type to are the same
3190 then if this is the only use then packit */
3191 if (compareType (operandType (IC_RIGHT (ic)),
3192 operandType (IC_LEFT (ic))) == 1)
3194 iCode *dic = packRegsForOneuse (ic, IC_RIGHT (ic), ebp);
3197 bitVectUnSetBit(OP_SYMBOL(IC_RESULT(dic))->defs,dic->key);
3198 ReplaceOpWithCheaperOp(&IC_RESULT (dic), IC_RESULT (ic));
3199 remiCodeFromeBBlock (ebp, ic);
3200 bitVectUnSetBit(OP_SYMBOL(IC_RESULT(ic))->defs,ic->key);
3201 hTabDeleteItem (&iCodehTab, ic->key, ic, DELETE_ITEM, NULL);
3202 OP_DEFS(IC_RESULT (dic))=bitVectSetBit (OP_DEFS (IC_RESULT (dic)), dic->key);
3210 iTempNN := (some variable in farspace) V1
3215 if (ic->op == IPUSH)
3217 packForPush (ic, ebpp, blockno);
3221 /* pack registers for accumulator use, when the
3222 result of an arithmetic or bit wise operation
3223 has only one use, that use is immediately following
3224 the defintion and the using iCode has only one
3225 operand or has two operands but one is literal &
3226 the result of that operation is not on stack then
3227 we can leave the result of this operation in acc:b
3229 if ((IS_ARITHMETIC_OP (ic)
3230 || IS_CONDITIONAL(ic)
3231 || IS_BITWISE_OP (ic)
3232 || ic->op == LEFT_OP || ic->op == RIGHT_OP || ic->op == CALL
3233 || (ic->op == ADDRESS_OF && isOperandOnStack (IC_LEFT (ic)))
3235 IS_ITEMP (IC_RESULT (ic)) &&
3236 getSize (operandType (IC_RESULT (ic))) <= 2)
3238 packRegsForAccUse (ic);
3242 /*-----------------------------------------------------------------*/
3243 /* assignRegisters - assigns registers to each live range as need */
3244 /*-----------------------------------------------------------------*/
3246 mcs51_assignRegisters (ebbIndex * ebbi)
3248 eBBlock ** ebbs = ebbi->bbOrder;
3249 int count = ebbi->count;
3253 setToNull ((void *) &_G.funcrUsed);
3254 setToNull ((void *) &_G.regAssigned);
3255 setToNull ((void *) &_G.totRegAssigned);
3256 mcs51_ptrRegReq = _G.stackExtend = _G.dataExtend = 0;
3257 if ((currFunc && IFFUNC_ISREENT (currFunc->type)) || options.stackAuto)
3265 _G.allBitregs = findAllBitregs ();
3268 /* change assignments this will remove some
3269 live ranges reducing some register pressure */
3271 for (i = 0; i < count; i++)
3272 packRegisters (ebbs, i);
3274 /* liveranges probably changed by register packing
3275 so we compute them again */
3276 recomputeLiveRanges (ebbs, count);
3278 if (options.dump_pack)
3279 dumpEbbsToFileExt (DUMP_PACK, ebbi);
3281 /* first determine for each live range the number of
3282 registers & the type of registers required for each */
3285 /* and serially allocate registers */
3286 serialRegAssign (ebbs, count);
3289 //setToNull ((void *) &_G.regAssigned);
3290 //setToNull ((void *) &_G.totRegAssigned);
3293 /* if stack was extended then tell the user */
3296 /* werror(W_TOOMANY_SPILS,"stack", */
3297 /* _G.stackExtend,currFunc->name,""); */
3303 /* werror(W_TOOMANY_SPILS,"data space", */
3304 /* _G.dataExtend,currFunc->name,""); */
3308 /* after that create the register mask
3309 for each of the instruction */
3310 createRegMask (ebbs, count);
3312 /* redo that offsets for stacked automatic variables */
3314 redoStackOffsets ();
3317 /* make sure r0 & r1 are flagged as used if they might be used */
3319 if (currFunc && mcs51_ptrRegReq)
3321 currFunc->regsUsed = bitVectSetBit (currFunc->regsUsed, R0_IDX);
3322 currFunc->regsUsed = bitVectSetBit (currFunc->regsUsed, R1_IDX);
3325 if (options.dump_rassgn)
3327 dumpEbbsToFileExt (DUMP_RASSGN, ebbi);
3328 dumpLiveRanges (DUMP_LRANGE, liveRanges);
3331 /* do the overlaysegment stuff SDCCmem.c */
3332 doOverlays (ebbs, count);
3334 /* now get back the chain */
3335 ic = iCodeLabelOptimize (iCodeFromeBBlock (ebbs, count));
3339 /* free up any _G.stackSpil locations allocated */
3340 applyToSet (_G.stackSpil, deallocStackSpil);
3342 setToNull ((void *) &_G.stackSpil);
3343 setToNull ((void *) &_G.spiltSet);
3344 /* mark all registers as free */