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)
1835 iCode *ic = sym->rematiCode;
1842 /* if plus or minus print the right hand side */
1843 if (ic->op == '+' || ic->op == '-')
1845 SNPRINTF (s, sizeof(buffer) - strlen(buffer),
1846 "0x%04x %c ", (int) operandLitValue (IC_RIGHT (ic)),
1849 ic = OP_SYMBOL (IC_LEFT (ic))->rematiCode;
1853 /* cast then continue */
1854 if (IS_CAST_ICODE(ic)) {
1855 ic = OP_SYMBOL (IC_RIGHT (ic))->rematiCode;
1858 /* we reached the end */
1859 SNPRINTF (s, sizeof(buffer) - strlen(buffer),
1860 "%s", OP_SYMBOL (IC_LEFT (ic))->rname);
1867 /*-----------------------------------------------------------------*/
1868 /* regTypeNum - computes the type & number of registers required */
1869 /*-----------------------------------------------------------------*/
1871 regTypeNum (eBBlock *ebbs)
1877 /* for each live range do */
1878 for (sym = hTabFirstItem (liveRanges, &k); sym;
1879 sym = hTabNextItem (liveRanges, &k))
1882 /* if used zero times then no registers needed */
1883 if ((sym->liveTo - sym->liveFrom) == 0)
1887 /* if the live range is a temporary */
1891 /* if the type is marked as a conditional */
1892 if (sym->regType == REG_CND)
1895 /* if used in return only then we don't
1897 if (sym->ruonly || sym->accuse)
1899 if (IS_AGGREGATE (sym->type) || sym->isptr)
1900 sym->type = aggrToPtr (sym->type, FALSE);
1904 /* if the symbol has only one definition &
1905 that definition is a get_pointer */
1906 if (bitVectnBitsOn (sym->defs) == 1 &&
1907 (ic = hTabItemWithKey (iCodehTab,
1908 bitVectFirstBit (sym->defs))) &&
1910 !IS_BITVAR (sym->etype) &&
1911 (aggrToPtrDclType (operandType (IC_LEFT (ic)), FALSE) == POINTER))
1914 if (ptrPseudoSymSafe (sym, ic))
1916 ptrPseudoSymConvert (sym, ic, rematStr (OP_SYMBOL (IC_LEFT (ic))));
1920 /* if in data space or idata space then try to
1921 allocate pointer register */
1925 /* if not then we require registers */
1926 sym->nRegs = ((IS_AGGREGATE (sym->type) || sym->isptr) ?
1927 getSize (sym->type = aggrToPtr (sym->type, FALSE)) :
1928 getSize (sym->type));
1932 fprintf (stderr, "allocated more than 4 or 0 registers for type ");
1933 printTypeChain (sym->type, stderr);
1934 fprintf (stderr, "\n");
1937 /* determine the type of register required */
1938 if (sym->nRegs == 1 && IS_PTR (sym->type) && sym->uptr)
1939 sym->regType = REG_PTR;
1940 else if (IS_BIT(sym->type))
1941 sym->regType = REG_BIT;
1943 sym->regType = REG_GPR;
1946 /* for the first run we don't provide */
1947 /* registers for true symbols we will */
1948 /* see how things go */
1954 /*-----------------------------------------------------------------*/
1955 /* freeAllRegs - mark all registers as free */
1956 /*-----------------------------------------------------------------*/
1962 for (i = 0; i < mcs51_nRegs; i++)
1963 regs8051[i].isFree = 1;
1966 /*-----------------------------------------------------------------*/
1967 /* deallocStackSpil - this will set the stack pointer back */
1968 /*-----------------------------------------------------------------*/
1970 DEFSETFUNC (deallocStackSpil)
1978 /*-----------------------------------------------------------------*/
1979 /* farSpacePackable - returns the packable icode for far variables */
1980 /*-----------------------------------------------------------------*/
1982 farSpacePackable (iCode * ic)
1986 /* go thru till we find a definition for the
1987 symbol on the right */
1988 for (dic = ic->prev; dic; dic = dic->prev)
1990 /* if the definition is a call then no */
1991 if ((dic->op == CALL || dic->op == PCALL) &&
1992 IC_RESULT (dic)->key == IC_RIGHT (ic)->key)
1997 /* if shift by unknown amount then not */
1998 if ((dic->op == LEFT_OP || dic->op == RIGHT_OP) &&
1999 IC_RESULT (dic)->key == IC_RIGHT (ic)->key)
2002 /* if pointer get and size > 1 */
2003 if (POINTER_GET (dic) &&
2004 getSize (aggrToPtr (operandType (IC_LEFT (dic)), FALSE)) > 1)
2007 if (POINTER_SET (dic) &&
2008 getSize (aggrToPtr (operandType (IC_RESULT (dic)), FALSE)) > 1)
2013 if (IC_COND (dic) &&
2014 IS_TRUE_SYMOP (IC_COND (dic)) &&
2015 isOperandInFarSpace (IC_COND (dic)))
2018 else if (dic->op == JUMPTABLE)
2020 if (IC_JTCOND (dic) &&
2021 IS_TRUE_SYMOP (IC_JTCOND (dic)) &&
2022 isOperandInFarSpace (IC_JTCOND (dic)))
2027 /* if any tree is a true symbol in far space */
2028 if (IC_RESULT (dic) &&
2029 IS_TRUE_SYMOP (IC_RESULT (dic)) &&
2030 isOperandInFarSpace (IC_RESULT (dic)))
2033 if (IC_RIGHT (dic) &&
2034 IS_TRUE_SYMOP (IC_RIGHT (dic)) &&
2035 isOperandInFarSpace (IC_RIGHT (dic)) &&
2036 !isOperandEqual (IC_RIGHT (dic), IC_RESULT (ic)))
2039 if (IC_LEFT (dic) &&
2040 IS_TRUE_SYMOP (IC_LEFT (dic)) &&
2041 isOperandInFarSpace (IC_LEFT (dic)) &&
2042 !isOperandEqual (IC_LEFT (dic), IC_RESULT (ic)))
2046 if (isOperandEqual (IC_RIGHT (ic), IC_RESULT (dic)))
2048 if ((dic->op == LEFT_OP ||
2049 dic->op == RIGHT_OP ||
2051 IS_OP_LITERAL (IC_RIGHT (dic)))
2061 /*-----------------------------------------------------------------*/
2062 /* packRegsForAssign - register reduction for assignment */
2063 /*-----------------------------------------------------------------*/
2065 packRegsForAssign (iCode * ic, eBBlock * ebp)
2069 if (!IS_ITEMP (IC_RIGHT (ic)) ||
2070 OP_SYMBOL (IC_RIGHT (ic))->isind ||
2071 OP_LIVETO (IC_RIGHT (ic)) > ic->seq)
2076 /* if the true symbol is defined in far space or on stack
2077 then we should not since this will increase register pressure */
2078 if (isOperandInFarSpace(IC_RESULT(ic)) && !farSpacePackable(ic)) {
2082 /* find the definition of iTempNN scanning backwards if we find a
2083 a use of the true symbol in before we find the definition then
2085 for (dic = ic->prev; dic; dic = dic->prev)
2087 int crossedCall = 0;
2089 /* We can pack across a function call only if it's a local */
2090 /* variable or our parameter. Never pack global variables */
2091 /* or parameters to a function we call. */
2092 if ((dic->op == CALL || dic->op == PCALL))
2094 if (!OP_SYMBOL (IC_RESULT (ic))->ismyparm
2095 && !OP_SYMBOL (IC_RESULT (ic))->islocal)
2106 if (IS_SYMOP (IC_COND (dic)) &&
2107 (IC_COND (dic)->key == IC_RESULT (ic)->key ||
2108 IC_COND (dic)->key == IC_RIGHT (ic)->key))
2116 if (IS_TRUE_SYMOP (IC_RESULT (dic)) &&
2117 IS_OP_VOLATILE (IC_RESULT (dic)))
2123 if (IS_SYMOP (IC_RESULT (dic)) &&
2124 IC_RESULT (dic)->key == IC_RIGHT (ic)->key)
2126 if (POINTER_SET (dic))
2132 if (IS_SYMOP (IC_RIGHT (dic)) &&
2133 (IC_RIGHT (dic)->key == IC_RESULT (ic)->key ||
2134 IC_RIGHT (dic)->key == IC_RIGHT (ic)->key))
2140 if (IS_SYMOP (IC_LEFT (dic)) &&
2141 (IC_LEFT (dic)->key == IC_RESULT (ic)->key ||
2142 IC_LEFT (dic)->key == IC_RIGHT (ic)->key))
2148 if (IS_SYMOP (IC_RESULT (dic)) &&
2149 IC_RESULT (dic)->key == IC_RESULT (ic)->key)
2165 return 0; /* did not find */
2167 /* if assignment then check that right is not a bit */
2168 if (ASSIGNMENT (ic) && !POINTER_SET (ic))
2170 sym_link *etype = operandType (IC_RESULT (dic));
2171 if (IS_BITFIELD (etype))
2173 /* if result is a bit too then it's ok */
2174 etype = operandType (IC_RESULT (ic));
2175 if (!IS_BITFIELD (etype))
2182 /* if the result is on stack or iaccess then it must be
2183 the same atleast one of the operands */
2184 if (OP_SYMBOL (IC_RESULT (ic))->onStack ||
2185 OP_SYMBOL (IC_RESULT (ic))->iaccess)
2188 /* the operation has only one symbol
2189 operator then we can pack */
2190 if ((IC_LEFT (dic) && !IS_SYMOP (IC_LEFT (dic))) ||
2191 (IC_RIGHT (dic) && !IS_SYMOP (IC_RIGHT (dic))))
2194 if (!((IC_LEFT (dic) &&
2195 IC_RESULT (ic)->key == IC_LEFT (dic)->key) ||
2197 IC_RESULT (ic)->key == IC_RIGHT (dic)->key)))
2201 /* found the definition */
2202 /* replace the result with the result of */
2203 /* this assignment and remove this assignment */
2204 bitVectUnSetBit(OP_SYMBOL(IC_RESULT(dic))->defs,dic->key);
2205 ReplaceOpWithCheaperOp(&IC_RESULT (dic), IC_RESULT (ic));
2207 if (IS_ITEMP (IC_RESULT (dic)) && OP_SYMBOL (IC_RESULT (dic))->liveFrom > dic->seq)
2209 OP_SYMBOL (IC_RESULT (dic))->liveFrom = dic->seq;
2211 // TODO: and the otherway around?
2213 /* delete from liverange table also
2214 delete from all the points inbetween and the new
2216 for (sic = dic; sic != ic; sic = sic->next)
2218 bitVectUnSetBit (sic->rlive, IC_RESULT (ic)->key);
2219 if (IS_ITEMP (IC_RESULT (dic)))
2220 bitVectSetBit (sic->rlive, IC_RESULT (dic)->key);
2223 remiCodeFromeBBlock (ebp, ic);
2224 bitVectUnSetBit(OP_SYMBOL(IC_RESULT(ic))->defs,ic->key);
2225 hTabDeleteItem (&iCodehTab, ic->key, ic, DELETE_ITEM, NULL);
2226 OP_DEFS(IC_RESULT (dic))=bitVectSetBit (OP_DEFS (IC_RESULT (dic)), dic->key);
2230 /*------------------------------------------------------------------*/
2231 /* findAssignToSym : scanning backwards looks for first assig found */
2232 /*------------------------------------------------------------------*/
2234 findAssignToSym (operand * op, iCode * ic)
2238 /* This routine is used to find sequences like
2240 ...; (intervening ops don't use iTempAA or modify FOO)
2241 blah = blah + iTempAA;
2243 and eliminate the use of iTempAA, freeing up its register for
2247 for (dic = ic->prev; dic; dic = dic->prev)
2250 /* if definition by assignment */
2251 if (dic->op == '=' &&
2252 !POINTER_SET (dic) &&
2253 IC_RESULT (dic)->key == op->key
2254 /* && IS_TRUE_SYMOP(IC_RIGHT(dic)) */
2256 break; /* found where this temp was defined */
2258 /* if we find an usage then we cannot delete it */
2262 if (IC_COND (dic) && IC_COND (dic)->key == op->key)
2265 else if (dic->op == JUMPTABLE)
2267 if (IC_JTCOND (dic) && IC_JTCOND (dic)->key == op->key)
2272 if (IC_LEFT (dic) && IC_LEFT (dic)->key == op->key)
2275 if (IC_RIGHT (dic) && IC_RIGHT (dic)->key == op->key)
2278 if (POINTER_SET (dic) && IC_RESULT (dic)->key == op->key)
2284 return NULL; /* didn't find any assignment to op */
2286 /* we are interested only if defined in far space */
2287 /* or in stack space in case of + & - */
2289 /* if assigned to a non-symbol then don't repack regs */
2290 if (!IS_SYMOP (IC_RIGHT (dic)))
2293 /* if the symbol is volatile then we should not */
2294 if (isOperandVolatile (IC_RIGHT (dic), TRUE))
2296 /* XXX TODO --- should we be passing FALSE to isOperandVolatile()?
2297 What does it mean for an iTemp to be volatile, anyway? Passing
2298 TRUE is more cautious but may prevent possible optimizations */
2300 /* if the symbol is in far space then we should not */
2301 if (isOperandInFarSpace (IC_RIGHT (dic)))
2304 /* for + & - operations make sure that
2305 if it is on the stack it is the same
2306 as one of the three operands */
2307 if ((ic->op == '+' || ic->op == '-') &&
2308 OP_SYMBOL (IC_RIGHT (dic))->onStack)
2311 if (IC_RESULT (ic)->key != IC_RIGHT (dic)->key &&
2312 IC_LEFT (ic)->key != IC_RIGHT (dic)->key &&
2313 IC_RIGHT (ic)->key != IC_RIGHT (dic)->key)
2317 /* now make sure that the right side of dic
2318 is not defined between ic & dic */
2321 iCode *sic = dic->next;
2323 for (; sic != ic; sic = sic->next)
2324 if (IC_RESULT (sic) &&
2325 IC_RESULT (sic)->key == IC_RIGHT (dic)->key)
2332 /*-----------------------------------------------------------------*/
2333 /* reassignAliasedSym - used by packRegsForSupport to replace */
2334 /* redundant iTemp with equivalent symbol */
2335 /*-----------------------------------------------------------------*/
2337 reassignAliasedSym (eBBlock *ebp, iCode *assignment, iCode *use, operand *op)
2340 unsigned oldSymKey, newSymKey;
2342 oldSymKey = op->key;
2343 newSymKey = IC_RIGHT(assignment)->key;
2345 /* only track live ranges of compiler-generated temporaries */
2346 if (!IS_ITEMP(IC_RIGHT(assignment)))
2349 /* update the live-value bitmaps */
2350 for (ic = assignment; ic != use; ic = ic->next) {
2351 bitVectUnSetBit (ic->rlive, oldSymKey);
2353 ic->rlive = bitVectSetBit (ic->rlive, newSymKey);
2356 /* update the sym of the used operand */
2357 OP_SYMBOL(op) = OP_SYMBOL(IC_RIGHT(assignment));
2358 op->key = OP_SYMBOL(op)->key;
2359 OP_SYMBOL(op)->accuse = 0;
2361 /* update the sym's liverange */
2362 if ( OP_LIVETO(op) < ic->seq )
2363 setToRange(op, ic->seq, FALSE);
2365 /* remove the assignment iCode now that its result is unused */
2366 remiCodeFromeBBlock (ebp, assignment);
2367 bitVectUnSetBit(OP_SYMBOL(IC_RESULT(assignment))->defs, assignment->key);
2368 hTabDeleteItem (&iCodehTab, assignment->key, assignment, DELETE_ITEM, NULL);
2372 /*-----------------------------------------------------------------*/
2373 /* packRegsForSupport :- reduce some registers for support calls */
2374 /*-----------------------------------------------------------------*/
2376 packRegsForSupport (iCode * ic, eBBlock * ebp)
2380 /* for the left & right operand :- look to see if the
2381 left was assigned a true symbol in far space in that
2382 case replace them */
2384 if (IS_ITEMP (IC_LEFT (ic)) &&
2385 OP_SYMBOL (IC_LEFT (ic))->liveTo <= ic->seq)
2387 dic = findAssignToSym (IC_LEFT (ic), ic);
2391 /* found it we need to remove it from the block */
2392 reassignAliasedSym (ebp, dic, ic, IC_LEFT(ic));
2397 /* do the same for the right operand */
2398 if (IS_ITEMP (IC_RIGHT (ic)) &&
2399 OP_SYMBOL (IC_RIGHT (ic))->liveTo <= ic->seq)
2401 iCode *dic = findAssignToSym (IC_RIGHT (ic), ic);
2405 /* if this is a subtraction & the result
2406 is a true symbol in far space then don't pack */
2407 if (ic->op == '-' && IS_TRUE_SYMOP (IC_RESULT (dic)))
2409 sym_link *etype = getSpec (operandType (IC_RESULT (dic)));
2410 if (IN_FARSPACE (SPEC_OCLS (etype)))
2413 /* found it we need to remove it from the
2415 reassignAliasedSym (ebp, dic, ic, IC_RIGHT(ic));
2424 #define IS_OP_RUONLY(x) (x && IS_SYMOP(x) && OP_SYMBOL(x)->ruonly)
2427 /*-----------------------------------------------------------------*/
2428 /* packRegsForOneuse : - will reduce some registers for single Use */
2429 /*-----------------------------------------------------------------*/
2431 packRegsForOneuse (iCode * ic, operand * op, eBBlock * ebp)
2435 /* if returning a literal then do nothing */
2439 /* if rematerializable or already return use then do nothing */
2440 if (OP_SYMBOL(op)->remat || OP_SYMBOL(op)->ruonly)
2443 /* only upto 2 bytes since we cannot predict
2444 the usage of b, & acc */
2445 if (getSize (operandType (op)) > (fReturnSizeMCS51 - 2))
2448 if (ic->op != RETURN &&
2450 !POINTER_SET (ic) &&
2454 if (ic->op == SEND && ic->argreg != 1) return NULL;
2456 /* this routine will mark the a symbol as used in one
2457 instruction use only && if the defintion is local
2458 (ie. within the basic block) && has only one definition &&
2459 that definition is either a return value from a
2460 function or does not contain any variables in
2462 if (bitVectnBitsOn (OP_USES (op)) > 1)
2465 /* if it has only one defintion */
2466 if (bitVectnBitsOn (OP_DEFS (op)) > 1)
2467 return NULL; /* has more than one definition */
2469 /* get that definition */
2471 hTabItemWithKey (iCodehTab,
2472 bitVectFirstBit (OP_DEFS (op)))))
2475 /* if that only usage is a cast */
2476 if (dic->op == CAST) {
2477 /* to a bigger type */
2478 if (getSize(OP_SYM_TYPE(IC_RESULT(dic))) >
2479 getSize(OP_SYM_TYPE(IC_RIGHT(dic)))) {
2480 /* than we can not, since we cannot predict the usage of b & acc */
2485 /* found the definition now check if it is local */
2486 if (dic->seq < ebp->fSeq ||
2487 dic->seq > ebp->lSeq)
2488 return NULL; /* non-local */
2490 /* now check if it is the return from
2492 if (dic->op == CALL || dic->op == PCALL)
2494 if (ic->op != SEND && ic->op != RETURN &&
2495 !POINTER_SET(ic) && !POINTER_GET(ic))
2497 OP_SYMBOL (op)->ruonly = 1;
2503 /* otherwise check that the definition does
2504 not contain any symbols in far space */
2505 if (isOperandInFarSpace (IC_LEFT (dic)) ||
2506 isOperandInFarSpace (IC_RIGHT (dic)) ||
2507 IS_OP_RUONLY (IC_LEFT (ic)) ||
2508 IS_OP_RUONLY (IC_RIGHT (ic)))
2513 /* if pointer set then make sure the pointer
2515 if (POINTER_SET (dic) &&
2516 !IS_DATA_PTR (aggrToPtr (operandType (IC_RESULT (dic)), FALSE)))
2519 if (POINTER_GET (dic) &&
2520 !IS_DATA_PTR (aggrToPtr (operandType (IC_LEFT (dic)), FALSE)))
2524 /* Make sure no overlapping liverange is already assigned to DPTR */
2525 if (OP_SYMBOL(op)->clashes)
2530 for (i = 0 ; i < OP_SYMBOL(op)->clashes->size ; i++ )
2532 if (bitVectBitValue(OP_SYMBOL(op)->clashes,i))
2534 sym = hTabItemWithKey(liveRanges,i);
2543 /* also make sure the intervenening instructions
2544 don't have any thing in far space */
2545 for (dic = dic->next; dic && dic != ic && sic != ic; dic = dic->next)
2548 /* if there is an intervening function call then no */
2549 if (dic->op == CALL || dic->op == PCALL)
2551 /* if pointer set then make sure the pointer
2553 if (POINTER_SET (dic) &&
2554 !IS_DATA_PTR (aggrToPtr (operandType (IC_RESULT (dic)), FALSE)))
2557 if (POINTER_GET (dic) &&
2558 !IS_DATA_PTR (aggrToPtr (operandType (IC_LEFT (dic)), FALSE)))
2561 /* if address of & the result is remat the okay */
2562 if (dic->op == ADDRESS_OF &&
2563 OP_SYMBOL (IC_RESULT (dic))->remat)
2566 /* if operand has size of three or more & this
2567 operation is a '*','/' or '%' then 'b' may
2569 if ((dic->op == '%' || dic->op == '/' || dic->op == '*') &&
2570 getSize (operandType (op)) >= 3)
2573 /* if left or right or result is in far space */
2574 if (isOperandInFarSpace (IC_LEFT (dic)) ||
2575 isOperandInFarSpace (IC_RIGHT (dic)) ||
2576 isOperandInFarSpace (IC_RESULT (dic)) ||
2577 IS_OP_RUONLY (IC_LEFT (dic)) ||
2578 IS_OP_RUONLY (IC_RIGHT (dic)) ||
2579 IS_OP_RUONLY (IC_RESULT (dic)))
2583 /* if left or right or result is on stack */
2584 if (isOperandOnStack(IC_LEFT(dic)) ||
2585 isOperandOnStack(IC_RIGHT(dic)) ||
2586 isOperandOnStack(IC_RESULT(dic))) {
2591 OP_SYMBOL (op)->ruonly = 1;
2595 /*-----------------------------------------------------------------*/
2596 /* isBitwiseOptimizable - requirements of JEAN LOUIS VERN */
2597 /*-----------------------------------------------------------------*/
2599 isBitwiseOptimizable (iCode * ic)
2601 sym_link *ltype = getSpec (operandType (IC_LEFT (ic)));
2602 sym_link *rtype = getSpec (operandType (IC_RIGHT (ic)));
2604 /* bitwise operations are considered optimizable
2605 under the following conditions (Jean-Louis VERN)
2617 if (IS_LITERAL(rtype) ||
2618 (IS_BITVAR (ltype) && IN_BITSPACE (SPEC_OCLS (ltype))))
2624 /*-----------------------------------------------------------------*/
2625 /* isCommutativeOp - tests whether this op cares what order its */
2626 /* operands are in */
2627 /*-----------------------------------------------------------------*/
2628 bool isCommutativeOp(unsigned int op)
2630 if (op == '+' || op == '*' || op == EQ_OP ||
2631 op == '^' || op == '|' || op == BITWISEAND)
2637 /*-----------------------------------------------------------------*/
2638 /* operandUsesAcc - determines whether the code generated for this */
2639 /* operand will have to use the accumulator */
2640 /*-----------------------------------------------------------------*/
2641 bool operandUsesAcc(operand *op)
2647 symbol *sym = OP_SYMBOL(op);
2651 return TRUE; /* duh! */
2653 if (IN_STACK(sym->etype) || sym->onStack ||
2654 (SPIL_LOC(op) && SPIL_LOC(op)->onStack))
2655 return TRUE; /* acc is used to calc stack offset */
2660 sym = SPIL_LOC(op); /* if spilled, look at spill location */
2662 return FALSE; /* more checks? */
2666 symspace = SPEC_OCLS(sym->etype);
2668 if (sym->iaccess && symspace->paged)
2669 return TRUE; /* must fetch paged indirect sym via accumulator */
2671 if (IN_BITSPACE(symspace))
2672 return TRUE; /* fetching bit vars uses the accumulator */
2674 if (IN_FARSPACE(symspace) || IN_CODESPACE(symspace))
2675 return TRUE; /* fetched via accumulator and dptr */
2681 /*-----------------------------------------------------------------*/
2682 /* packRegsForAccUse - pack registers for acc use */
2683 /*-----------------------------------------------------------------*/
2685 packRegsForAccUse (iCode * ic)
2689 /* if this is an aggregate, e.g. a one byte char array */
2690 if (IS_AGGREGATE(operandType(IC_RESULT(ic)))) {
2694 /* if we are calling a reentrant function that has stack parameters */
2695 if (ic->op == CALL &&
2696 IFFUNC_ISREENT(operandType(IC_LEFT(ic))) &&
2697 FUNC_HASSTACKPARM(operandType(IC_LEFT(ic))))
2700 if (ic->op == PCALL &&
2701 IFFUNC_ISREENT(operandType(IC_LEFT(ic))->next) &&
2702 FUNC_HASSTACKPARM(operandType(IC_LEFT(ic))->next))
2705 /* if + or - then it has to be one byte result */
2706 if ((ic->op == '+' || ic->op == '-')
2707 && getSize (operandType (IC_RESULT (ic))) > 1)
2710 /* if shift operation make sure right side is not a literal */
2711 if (ic->op == RIGHT_OP &&
2712 (isOperandLiteral (IC_RIGHT (ic)) ||
2713 getSize (operandType (IC_RESULT (ic))) > 1))
2716 if (ic->op == LEFT_OP &&
2717 (isOperandLiteral (IC_RIGHT (ic)) ||
2718 getSize (operandType (IC_RESULT (ic))) > 1))
2721 if (IS_BITWISE_OP (ic) &&
2722 getSize (operandType (IC_RESULT (ic))) > 1)
2726 /* has only one definition */
2727 if (bitVectnBitsOn (OP_DEFS (IC_RESULT (ic))) > 1)
2730 /* has only one use */
2731 if (bitVectnBitsOn (OP_USES (IC_RESULT (ic))) > 1)
2734 /* and the usage immediately follows this iCode */
2735 if (!(uic = hTabItemWithKey (iCodehTab,
2736 bitVectFirstBit (OP_USES (IC_RESULT (ic))))))
2739 if (ic->next != uic)
2742 /* if it is a conditional branch then we definitely can */
2746 if (uic->op == JUMPTABLE)
2749 if (POINTER_SET (uic) &&
2750 getSize (aggrToPtr (operandType (IC_RESULT (uic)), FALSE)) > 1)
2753 /* if the usage is not is an assignment
2754 or an arithmetic / bitwise / shift operation then not */
2755 if (uic->op != '=' &&
2756 !IS_ARITHMETIC_OP (uic) &&
2757 !IS_BITWISE_OP (uic) &&
2758 uic->op != LEFT_OP &&
2759 uic->op != RIGHT_OP)
2762 /* if used in ^ operation then make sure right is not a
2763 literal (WIML: Why is this?) */
2764 if (uic->op == '^' && isOperandLiteral (IC_RIGHT (uic)))
2767 /* if shift operation make sure right side is not a literal */
2768 /* WIML: Why is this? */
2769 if (uic->op == RIGHT_OP &&
2770 (isOperandLiteral (IC_RIGHT (uic)) ||
2771 getSize (operandType (IC_RESULT (uic))) > 1))
2773 if (uic->op == LEFT_OP &&
2774 (isOperandLiteral (IC_RIGHT (uic)) ||
2775 getSize (operandType (IC_RESULT (uic))) > 1))
2778 /* make sure that the result of this icode is not on the
2779 stack, since acc is used to compute stack offset */
2781 if (IS_TRUE_SYMOP (IC_RESULT (uic)) &&
2782 OP_SYMBOL (IC_RESULT (uic))->onStack)
2785 if (isOperandOnStack(IC_RESULT(uic)))
2789 /* if the usage has only one operand then we can */
2790 if (IC_LEFT (uic) == NULL ||
2791 IC_RIGHT (uic) == NULL)
2794 /* if the other operand uses the accumulator then we cannot */
2795 if ( (IC_LEFT(uic)->key == IC_RESULT(ic)->key &&
2796 operandUsesAcc(IC_RIGHT(uic))) ||
2797 (IC_RIGHT(uic)->key == IC_RESULT(ic)->key &&
2798 operandUsesAcc(IC_LEFT(uic))) )
2801 /* make sure this is on the left side if not commutative */
2802 /* except for '-', which has been written to be able to
2803 handle reversed operands */
2804 if (!(isCommutativeOp(ic->op) || ic->op == '-') &&
2805 IC_LEFT (uic)->key != IC_RESULT (ic)->key)
2809 // this is too dangerous and need further restrictions
2812 /* if one of them is a literal then we can */
2813 if ((IC_LEFT (uic) && IS_OP_LITERAL (IC_LEFT (uic))) ||
2814 (IC_RIGHT (uic) && IS_OP_LITERAL (IC_RIGHT (uic))))
2816 OP_SYMBOL (IC_RESULT (ic))->accuse = 1;
2822 OP_SYMBOL (IC_RESULT (ic))->accuse = 1;
2826 /*-----------------------------------------------------------------*/
2827 /* packForPush - heuristics to reduce iCode for pushing */
2828 /*-----------------------------------------------------------------*/
2830 packForPush (iCode * ic, eBBlock ** ebpp, int blockno)
2834 struct eBBlock * ebp=ebpp[blockno];
2836 if (ic->op != IPUSH || !IS_ITEMP (IC_LEFT (ic)))
2839 /* must have only definition & one usage */
2840 if (bitVectnBitsOn (OP_DEFS (IC_LEFT (ic))) != 1 ||
2841 bitVectnBitsOn (OP_USES (IC_LEFT (ic))) != 1)
2844 /* find the definition */
2845 if (!(dic = hTabItemWithKey (iCodehTab,
2846 bitVectFirstBit (OP_DEFS (IC_LEFT (ic))))))
2849 if (dic->op != '=' || POINTER_SET (dic))
2852 if (dic->seq < ebp->fSeq) { // Evelyn did this
2854 for (i=0; i<blockno; i++) {
2855 if (dic->seq >= ebpp[i]->fSeq && dic->seq <= ebpp[i]->lSeq) {
2860 wassert (i!=blockno); // no way to recover from here
2863 if (IS_SYMOP(IC_RIGHT(dic))) {
2864 /* make sure the right side does not have any definitions
2866 dbv = OP_DEFS(IC_RIGHT(dic));
2867 for (lic = ic; lic && lic != dic ; lic = lic->prev) {
2868 if (bitVectBitValue(dbv,lic->key))
2871 /* make sure they have the same type */
2872 if (IS_SPEC(operandType(IC_LEFT(ic))))
2874 sym_link *itype=operandType(IC_LEFT(ic));
2875 sym_link *ditype=operandType(IC_RIGHT(dic));
2877 if (SPEC_USIGN(itype)!=SPEC_USIGN(ditype) ||
2878 SPEC_LONG(itype)!=SPEC_LONG(ditype))
2881 /* extend the live range of replaced operand if needed */
2882 if (OP_SYMBOL(IC_RIGHT(dic))->liveTo < ic->seq) {
2883 OP_SYMBOL(IC_RIGHT(dic))->liveTo = ic->seq;
2885 bitVectUnSetBit(OP_SYMBOL(IC_RESULT(dic))->defs,dic->key);
2888 /* we now we know that it has one & only one def & use
2889 and the that the definition is an assignment */
2890 ReplaceOpWithCheaperOp(&IC_LEFT (ic), IC_RIGHT (dic));
2891 remiCodeFromeBBlock (ebp, dic);
2892 hTabDeleteItem (&iCodehTab, dic->key, dic, DELETE_ITEM, NULL);
2895 /*-----------------------------------------------------------------*/
2896 /* packRegisters - does some transformations to reduce register */
2898 /*-----------------------------------------------------------------*/
2900 packRegisters (eBBlock ** ebpp, int blockno)
2904 eBBlock *ebp=ebpp[blockno];
2910 /* look for assignments of the form */
2911 /* iTempNN = TRueSym (someoperation) SomeOperand */
2913 /* TrueSym := iTempNN:1 */
2914 for (ic = ebp->sch; ic; ic = ic->next)
2916 /* find assignment of the form TrueSym := iTempNN:1 */
2917 if (ic->op == '=' && !POINTER_SET (ic))
2918 change += packRegsForAssign (ic, ebp);
2925 for (ic = ebp->sch; ic; ic = ic->next)
2927 /* Fix for bug #979599: */
2930 /* Look for two subsequent iCodes with */
2932 /* _c = iTemp & op; */
2933 /* and replace them by */
2936 if ((ic->op == BITWISEAND || ic->op == '|' || ic->op == '^') &&
2938 ic->prev->op == '=' &&
2939 IS_ITEMP (IC_LEFT (ic)) &&
2940 IC_LEFT (ic) == IC_RESULT (ic->prev) &&
2941 isOperandEqual (IC_RESULT(ic), IC_RIGHT(ic->prev)))
2943 iCode* ic_prev = ic->prev;
2944 symbol* prev_result_sym = OP_SYMBOL (IC_RESULT (ic_prev));
2946 ReplaceOpWithCheaperOp (&IC_LEFT (ic), IC_RESULT (ic));
2947 if (IC_RESULT (ic_prev) != IC_RIGHT (ic))
2949 bitVectUnSetBit (OP_USES (IC_RESULT (ic_prev)), ic->key);
2950 if (/*IS_ITEMP (IC_RESULT (ic_prev)) && */
2951 prev_result_sym->liveTo == ic->seq)
2953 prev_result_sym->liveTo = ic_prev->seq;
2956 bitVectSetBit (OP_USES (IC_RESULT (ic)), ic->key);
2958 bitVectSetBit (ic->rlive, IC_RESULT (ic)->key);
2960 if (bitVectIsZero (OP_USES (IC_RESULT (ic_prev))))
2962 bitVectUnSetBit (ic->rlive, IC_RESULT (ic)->key);
2963 bitVectUnSetBit (OP_DEFS (IC_RESULT (ic_prev)), ic_prev->key);
2964 remiCodeFromeBBlock (ebp, ic_prev);
2965 hTabDeleteItem (&iCodehTab, ic_prev->key, ic_prev, DELETE_ITEM, NULL);
2969 /* if this is an itemp & result of an address of a true sym
2970 then mark this as rematerialisable */
2971 if (ic->op == ADDRESS_OF &&
2972 IS_ITEMP (IC_RESULT (ic)) &&
2973 IS_TRUE_SYMOP (IC_LEFT (ic)) &&
2974 bitVectnBitsOn (OP_DEFS (IC_RESULT (ic))) == 1 &&
2975 !OP_SYMBOL (IC_LEFT (ic))->onStack)
2977 OP_SYMBOL (IC_RESULT (ic))->remat = 1;
2978 OP_SYMBOL (IC_RESULT (ic))->rematiCode = ic;
2979 OP_SYMBOL (IC_RESULT (ic))->usl.spillLoc = NULL;
2982 /* if straight assignment then carry remat flag if
2983 this is the only definition */
2984 if (ic->op == '=' &&
2985 !POINTER_SET (ic) &&
2986 IS_SYMOP (IC_RIGHT (ic)) &&
2987 OP_SYMBOL (IC_RIGHT (ic))->remat &&
2988 !IS_CAST_ICODE(OP_SYMBOL (IC_RIGHT (ic))->rematiCode) &&
2989 bitVectnBitsOn (OP_SYMBOL (IC_RESULT (ic))->defs) <= 1)
2991 OP_SYMBOL (IC_RESULT (ic))->remat =
2992 OP_SYMBOL (IC_RIGHT (ic))->remat;
2993 OP_SYMBOL (IC_RESULT (ic))->rematiCode =
2994 OP_SYMBOL (IC_RIGHT (ic))->rematiCode;
2997 /* if cast to a generic pointer & the pointer being
2998 cast is remat, then we can remat this cast as well */
2999 if (ic->op == CAST &&
3000 IS_SYMOP(IC_RIGHT(ic)) &&
3001 OP_SYMBOL(IC_RIGHT(ic))->remat &&
3002 bitVectnBitsOn (OP_DEFS (IC_RESULT (ic))) == 1)
3004 sym_link *to_type = operandType(IC_LEFT(ic));
3005 sym_link *from_type = operandType(IC_RIGHT(ic));
3006 if (IS_GENPTR(to_type) && IS_PTR(from_type))
3008 OP_SYMBOL (IC_RESULT (ic))->remat = 1;
3009 OP_SYMBOL (IC_RESULT (ic))->rematiCode = ic;
3010 OP_SYMBOL (IC_RESULT (ic))->usl.spillLoc = NULL;
3014 /* if this is a +/- operation with a rematerizable
3015 then mark this as rematerializable as well */
3016 if ((ic->op == '+' || ic->op == '-') &&
3017 (IS_SYMOP (IC_LEFT (ic)) &&
3018 IS_ITEMP (IC_RESULT (ic)) &&
3019 IS_OP_LITERAL (IC_RIGHT (ic))) &&
3020 OP_SYMBOL (IC_LEFT (ic))->remat &&
3021 (!IS_SYMOP (IC_RIGHT (ic)) || !IS_CAST_ICODE(OP_SYMBOL (IC_RIGHT (ic))->rematiCode)) &&
3022 bitVectnBitsOn (OP_DEFS (IC_RESULT (ic))) == 1)
3024 OP_SYMBOL (IC_RESULT (ic))->remat = 1;
3025 OP_SYMBOL (IC_RESULT (ic))->rematiCode = ic;
3026 OP_SYMBOL (IC_RESULT (ic))->usl.spillLoc = NULL;
3029 /* mark the pointer usages */
3030 if (POINTER_SET (ic))
3031 OP_SYMBOL (IC_RESULT (ic))->uptr = 1;
3033 if (POINTER_GET (ic) &&
3034 IS_SYMOP(IC_LEFT (ic)))
3035 OP_SYMBOL (IC_LEFT (ic))->uptr = 1;
3039 /* if we are using a symbol on the stack
3040 then we should say mcs51_ptrRegReq */
3041 if (options.useXstack && ic->parmPush
3042 && (ic->op == IPUSH || ic->op == IPOP))
3044 if (ic->op == IFX && IS_SYMOP (IC_COND (ic)))
3045 mcs51_ptrRegReq += ((OP_SYMBOL (IC_COND (ic))->onStack ||
3046 OP_SYMBOL (IC_COND (ic))->iaccess ||
3047 SPEC_OCLS(OP_SYMBOL (IC_COND (ic))->etype) == idata) ? 1 : 0);
3048 else if (ic->op == JUMPTABLE && IS_SYMOP (IC_JTCOND (ic)))
3049 mcs51_ptrRegReq += ((OP_SYMBOL (IC_JTCOND (ic))->onStack ||
3050 OP_SYMBOL (IC_JTCOND (ic))->iaccess ||
3051 SPEC_OCLS(OP_SYMBOL (IC_JTCOND (ic))->etype) == idata) ? 1 : 0);
3054 if (IS_SYMOP (IC_LEFT (ic)))
3055 mcs51_ptrRegReq += ((OP_SYMBOL (IC_LEFT (ic))->onStack ||
3056 OP_SYMBOL (IC_LEFT (ic))->iaccess ||
3057 SPEC_OCLS(OP_SYMBOL (IC_LEFT (ic))->etype) == idata) ? 1 : 0);
3058 if (IS_SYMOP (IC_RIGHT (ic)))
3059 mcs51_ptrRegReq += ((OP_SYMBOL (IC_RIGHT (ic))->onStack ||
3060 OP_SYMBOL (IC_RIGHT (ic))->iaccess ||
3061 SPEC_OCLS(OP_SYMBOL (IC_RIGHT (ic))->etype) == idata) ? 1 : 0);
3062 if (IS_SYMOP (IC_RESULT (ic)))
3063 mcs51_ptrRegReq += ((OP_SYMBOL (IC_RESULT (ic))->onStack ||
3064 OP_SYMBOL (IC_RESULT (ic))->iaccess ||
3065 SPEC_OCLS(OP_SYMBOL (IC_RESULT (ic))->etype) == idata) ? 1 : 0);
3066 if (POINTER_GET (ic) && IS_SYMOP (IC_LEFT (ic))
3067 && getSize (OP_SYMBOL (IC_LEFT (ic))->type) <= (unsigned int) PTRSIZE)
3069 if (POINTER_SET (ic) && IS_SYMOP (IC_RESULT (ic))
3070 && getSize (OP_SYMBOL (IC_RESULT (ic))->type) <= (unsigned int) PTRSIZE)
3075 /* if the condition of an if instruction
3076 is defined in the previous instruction and
3077 this is the only usage then
3078 mark the itemp as a conditional */
3079 if ((IS_CONDITIONAL (ic) ||
3080 (IS_BITWISE_OP(ic) && isBitwiseOptimizable (ic))) &&
3081 ic->next && ic->next->op == IFX &&
3082 bitVectnBitsOn (OP_USES(IC_RESULT(ic)))==1 &&
3083 isOperandEqual (IC_RESULT (ic), IC_COND (ic->next)) &&
3084 OP_SYMBOL (IC_RESULT (ic))->liveTo <= ic->next->seq)
3086 OP_SYMBOL (IC_RESULT (ic))->regType = REG_CND;
3090 /* if the condition of an if instruction
3091 is defined in the previous GET_POINTER instruction and
3092 this is the only usage then
3093 mark the itemp as accumulator use */
3094 if ((POINTER_GET (ic) && getSize (operandType (IC_RESULT (ic))) <=1) &&
3095 ic->next && ic->next->op == IFX &&
3096 bitVectnBitsOn (OP_USES(IC_RESULT(ic)))==1 &&
3097 isOperandEqual (IC_RESULT (ic), IC_COND (ic->next)) &&
3098 OP_SYMBOL (IC_RESULT (ic))->liveTo <= ic->next->seq)
3100 OP_SYMBOL (IC_RESULT (ic))->accuse = 1;
3104 /* reduce for support function calls */
3105 if (ic->supportRtn || ic->op == '+' || ic->op == '-')
3106 packRegsForSupport (ic, ebp);
3108 /* some cases the redundant moves can
3109 can be eliminated for return statements */
3110 if ((ic->op == RETURN || (ic->op == SEND && ic->argreg == 1)) &&
3111 !isOperandInFarSpace (IC_LEFT (ic)) &&
3112 options.model == MODEL_SMALL) {
3113 packRegsForOneuse (ic, IC_LEFT (ic), ebp);
3116 /* if pointer set & left has a size more than
3117 one and right is not in far space */
3118 if (POINTER_SET (ic) &&
3119 !isOperandInFarSpace (IC_RIGHT (ic)) &&
3120 !OP_SYMBOL (IC_RESULT (ic))->remat &&
3121 !IS_OP_RUONLY (IC_RIGHT (ic)) &&
3122 getSize (aggrToPtr (operandType (IC_RESULT (ic)), FALSE)) > 1)
3123 packRegsForOneuse (ic, IC_RESULT (ic), ebp);
3125 /* if pointer get */
3126 if (POINTER_GET (ic) &&
3127 IS_SYMOP (IC_LEFT (ic)) &&
3128 !isOperandInFarSpace (IC_RESULT (ic)) &&
3129 !OP_SYMBOL (IC_LEFT (ic))->remat &&
3130 !IS_OP_RUONLY (IC_RESULT (ic)) &&
3131 getSize (aggrToPtr (operandType (IC_LEFT (ic)), FALSE)) > 1)
3132 packRegsForOneuse (ic, IC_LEFT (ic), ebp);
3135 /* if this is a cast for intergral promotion then
3136 check if it's the only use of the definition of the
3137 operand being casted/ if yes then replace
3138 the result of that arithmetic operation with
3139 this result and get rid of the cast */
3142 sym_link *fromType = operandType (IC_RIGHT (ic));
3143 sym_link *toType = operandType (IC_LEFT (ic));
3145 if (IS_INTEGRAL (fromType) && IS_INTEGRAL (toType) &&
3146 getSize (fromType) != getSize (toType) &&
3147 SPEC_USIGN (fromType) == SPEC_USIGN (toType))
3150 iCode *dic = packRegsForOneuse (ic, IC_RIGHT (ic), ebp);
3153 if (IS_ARITHMETIC_OP (dic))
3155 bitVectUnSetBit(OP_SYMBOL(IC_RESULT(dic))->defs,dic->key);
3156 ReplaceOpWithCheaperOp(&IC_RESULT (dic), IC_RESULT (ic));
3157 remiCodeFromeBBlock (ebp, ic);
3158 bitVectUnSetBit(OP_SYMBOL(IC_RESULT(ic))->defs,ic->key);
3159 hTabDeleteItem (&iCodehTab, ic->key, ic, DELETE_ITEM, NULL);
3160 OP_DEFS(IC_RESULT (dic))=bitVectSetBit (OP_DEFS (IC_RESULT (dic)), dic->key);
3164 OP_SYMBOL (IC_RIGHT (ic))->ruonly = 0;
3170 /* if the type from and type to are the same
3171 then if this is the only use then packit */
3172 if (compareType (operandType (IC_RIGHT (ic)),
3173 operandType (IC_LEFT (ic))) == 1)
3175 iCode *dic = packRegsForOneuse (ic, IC_RIGHT (ic), ebp);
3178 bitVectUnSetBit(OP_SYMBOL(IC_RESULT(dic))->defs,dic->key);
3179 ReplaceOpWithCheaperOp(&IC_RESULT (dic), IC_RESULT (ic));
3180 remiCodeFromeBBlock (ebp, ic);
3181 bitVectUnSetBit(OP_SYMBOL(IC_RESULT(ic))->defs,ic->key);
3182 hTabDeleteItem (&iCodehTab, ic->key, ic, DELETE_ITEM, NULL);
3183 OP_DEFS(IC_RESULT (dic))=bitVectSetBit (OP_DEFS (IC_RESULT (dic)), dic->key);
3191 iTempNN := (some variable in farspace) V1
3196 if (ic->op == IPUSH)
3198 packForPush (ic, ebpp, blockno);
3202 /* pack registers for accumulator use, when the
3203 result of an arithmetic or bit wise operation
3204 has only one use, that use is immediately following
3205 the defintion and the using iCode has only one
3206 operand or has two operands but one is literal &
3207 the result of that operation is not on stack then
3208 we can leave the result of this operation in acc:b
3210 if ((IS_ARITHMETIC_OP (ic)
3211 || IS_CONDITIONAL(ic)
3212 || IS_BITWISE_OP (ic)
3213 || ic->op == LEFT_OP || ic->op == RIGHT_OP || ic->op == CALL
3214 || (ic->op == ADDRESS_OF && isOperandOnStack (IC_LEFT (ic)))
3216 IS_ITEMP (IC_RESULT (ic)) &&
3217 getSize (operandType (IC_RESULT (ic))) <= 2)
3219 packRegsForAccUse (ic);
3223 /*-----------------------------------------------------------------*/
3224 /* assignRegisters - assigns registers to each live range as need */
3225 /*-----------------------------------------------------------------*/
3227 mcs51_assignRegisters (ebbIndex * ebbi)
3229 eBBlock ** ebbs = ebbi->bbOrder;
3230 int count = ebbi->count;
3234 setToNull ((void *) &_G.funcrUsed);
3235 setToNull ((void *) &_G.regAssigned);
3236 setToNull ((void *) &_G.totRegAssigned);
3237 mcs51_ptrRegReq = _G.stackExtend = _G.dataExtend = 0;
3238 if ((currFunc && IFFUNC_ISREENT (currFunc->type)) || options.stackAuto)
3246 _G.allBitregs = findAllBitregs ();
3249 /* change assignments this will remove some
3250 live ranges reducing some register pressure */
3252 for (i = 0; i < count; i++)
3253 packRegisters (ebbs, i);
3255 /* liveranges probably changed by register packing
3256 so we compute them again */
3257 recomputeLiveRanges (ebbs, count);
3259 if (options.dump_pack)
3260 dumpEbbsToFileExt (DUMP_PACK, ebbi);
3262 /* first determine for each live range the number of
3263 registers & the type of registers required for each */
3266 /* and serially allocate registers */
3267 serialRegAssign (ebbs, count);
3270 //setToNull ((void *) &_G.regAssigned);
3271 //setToNull ((void *) &_G.totRegAssigned);
3274 /* if stack was extended then tell the user */
3277 /* werror(W_TOOMANY_SPILS,"stack", */
3278 /* _G.stackExtend,currFunc->name,""); */
3284 /* werror(W_TOOMANY_SPILS,"data space", */
3285 /* _G.dataExtend,currFunc->name,""); */
3289 /* after that create the register mask
3290 for each of the instruction */
3291 createRegMask (ebbs, count);
3293 /* redo that offsets for stacked automatic variables */
3295 redoStackOffsets ();
3298 /* make sure r0 & r1 are flagged as used if they might be used */
3300 if (currFunc && mcs51_ptrRegReq)
3302 currFunc->regsUsed = bitVectSetBit (currFunc->regsUsed, R0_IDX);
3303 currFunc->regsUsed = bitVectSetBit (currFunc->regsUsed, R1_IDX);
3306 if (options.dump_rassgn)
3308 dumpEbbsToFileExt (DUMP_RASSGN, ebbi);
3309 dumpLiveRanges (DUMP_LRANGE, liveRanges);
3312 /* do the overlaysegment stuff SDCCmem.c */
3313 doOverlays (ebbs, count);
3315 /* now get back the chain */
3316 ic = iCodeLabelOptimize (iCodeFromeBBlock (ebbs, count));
3320 /* free up any _G.stackSpil locations allocated */
3321 applyToSet (_G.stackSpil, deallocStackSpil);
3323 setToNull ((void *) &_G.stackSpil);
3324 setToNull ((void *) &_G.spiltSet);
3325 /* mark all registers as free */