1 /*------------------------------------------------------------------------
3 SDCCralloc.c - source file for register allocation. (8051) specific
5 Written By - Sandeep Dutta . sandeep.dutta@usa.net (1998)
7 This program is free software; you can redistribute it and/or modify it
8 under the terms of the GNU General Public License as published by the
9 Free Software Foundation; either version 2, or (at your option) any
12 This program is distributed in the hope that it will be useful,
13 but WITHOUT ANY WARRANTY; without even the implied warranty of
14 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
15 GNU General Public License for more details.
17 You should have received a copy of the GNU General Public License
18 along with this program; if not, write to the Free Software
19 Foundation, 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
21 In other words, you are welcome to use, share and improve this program.
22 You are forbidden to forbid anyone else to use, share and improve
23 what you give them. Help stamp out software-hoarding!
24 -------------------------------------------------------------------------*/
30 /*-----------------------------------------------------------------*/
31 /* At this point we start getting processor specific although */
32 /* some routines are non-processor specific & can be reused when */
33 /* targetting other processors. The decision for this will have */
34 /* to be made on a routine by routine basis */
35 /* routines used to pack registers are most definitely not reusable */
36 /* since the pack the registers depending strictly on the MCU */
37 /*-----------------------------------------------------------------*/
39 extern void gen51Code (iCode *);
48 bitVect *totRegAssigned; /* final set of LRs that got into registers */
51 bitVect *funcrUsed; /* registers used in a function */
57 /* Shared with gen.c */
58 int mcs51_ptrRegReq; /* one byte pointer register required */
64 {REG_GPR, R2_IDX, REG_GPR, "r2", "ar2", "0", 2, 1},
65 {REG_GPR, R3_IDX, REG_GPR, "r3", "ar3", "0", 3, 1},
66 {REG_GPR, R4_IDX, REG_GPR, "r4", "ar4", "0", 4, 1},
67 {REG_GPR, R5_IDX, REG_GPR, "r5", "ar5", "0", 5, 1},
68 {REG_GPR, R6_IDX, REG_GPR, "r6", "ar6", "0", 6, 1},
69 {REG_GPR, R7_IDX, REG_GPR, "r7", "ar7", "0", 7, 1},
70 {REG_PTR, R0_IDX, REG_PTR, "r0", "ar0", "0", 0, 1},
71 {REG_PTR, R1_IDX, REG_PTR, "r1", "ar1", "0", 1, 1},
72 {REG_GPR, X8_IDX, REG_GPR, "x8", "x8", "xreg", 0, 1},
73 {REG_GPR, X9_IDX, REG_GPR, "x9", "x9", "xreg", 1, 1},
74 {REG_GPR, X10_IDX, REG_GPR, "x10", "x10", "xreg", 2, 1},
75 {REG_GPR, X11_IDX, REG_GPR, "x11", "x11", "xreg", 3, 1},
76 {REG_GPR, X12_IDX, REG_GPR, "x12", "x12", "xreg", 4, 1},
77 {REG_CND, CND_IDX, REG_CND, "C", "C", "xreg", 0, 1},
80 static void spillThis (symbol *);
81 static void freeAllRegs ();
83 /*-----------------------------------------------------------------*/
84 /* allocReg - allocates register of given type */
85 /*-----------------------------------------------------------------*/
91 for (i = 0; i < mcs51_nRegs; i++)
94 /* if type is given as 0 then any
95 free register will do */
99 regs8051[i].isFree = 0;
102 bitVectSetBit (currFunc->regsUsed, i);
105 /* other wise look for specific type
107 if (regs8051[i].isFree &&
108 regs8051[i].type == type)
110 regs8051[i].isFree = 0;
113 bitVectSetBit (currFunc->regsUsed, i);
120 /*-----------------------------------------------------------------*/
121 /* mcs51_regWithIdx - returns pointer to register wit index number */
122 /*-----------------------------------------------------------------*/
124 mcs51_regWithIdx (int idx)
128 for (i = 0; i < mcs51_nRegs; i++)
129 if (regs8051[i].rIdx == idx)
132 werror (E_INTERNAL_ERROR, __FILE__, __LINE__,
133 "regWithIdx not found");
137 /*-----------------------------------------------------------------*/
138 /* freeReg - frees a register */
139 /*-----------------------------------------------------------------*/
145 werror (E_INTERNAL_ERROR, __FILE__, __LINE__,
146 "freeReg - Freeing NULL register");
154 /*-----------------------------------------------------------------*/
155 /* nFreeRegs - returns number of free registers */
156 /*-----------------------------------------------------------------*/
163 for (i = 0; i < mcs51_nRegs; i++)
164 if (regs8051[i].isFree && regs8051[i].type == type)
169 /*-----------------------------------------------------------------*/
170 /* nfreeRegsType - free registers with type */
171 /*-----------------------------------------------------------------*/
173 nfreeRegsType (int type)
178 if ((nfr = nFreeRegs (type)) == 0)
179 return nFreeRegs (REG_GPR);
182 return nFreeRegs (type);
185 /*-----------------------------------------------------------------*/
186 /* useReg - marks a register as used */
187 /*-----------------------------------------------------------------*/
194 /*-----------------------------------------------------------------*/
195 /* computeSpillable - given a point find the spillable live ranges */
196 /*-----------------------------------------------------------------*/
198 computeSpillable (iCode * ic)
202 /* spillable live ranges are those that are live at this
203 point . the following categories need to be subtracted
205 a) - those that are already spilt
206 b) - if being used by this one
207 c) - defined by this one */
209 spillable = bitVectCopy (ic->rlive);
211 bitVectCplAnd (spillable, _G.spiltSet); /* those already spilt */
213 bitVectCplAnd (spillable, ic->uses); /* used in this one */
214 bitVectUnSetBit (spillable, ic->defKey);
215 spillable = bitVectIntersect (spillable, _G.regAssigned);
220 /*-----------------------------------------------------------------*/
221 /* noSpilLoc - return true if a variable has no spil location */
222 /*-----------------------------------------------------------------*/
224 noSpilLoc (symbol * sym, eBBlock * ebp, iCode * ic)
226 return (sym->usl.spillLoc ? 0 : 1);
229 /*-----------------------------------------------------------------*/
230 /* hasSpilLoc - will return 1 if the symbol has spil location */
231 /*-----------------------------------------------------------------*/
233 hasSpilLoc (symbol * sym, eBBlock * ebp, iCode * ic)
235 return (sym->usl.spillLoc ? 1 : 0);
238 /*-----------------------------------------------------------------*/
239 /* directSpilLoc - will return 1 if the splilocation is in direct */
240 /*-----------------------------------------------------------------*/
242 directSpilLoc (symbol * sym, eBBlock * ebp, iCode * ic)
244 if (sym->usl.spillLoc &&
245 (IN_DIRSPACE (SPEC_OCLS (sym->usl.spillLoc->etype))))
251 /*-----------------------------------------------------------------*/
252 /* hasSpilLocnoUptr - will return 1 if the symbol has spil location */
253 /* but is not used as a pointer */
254 /*-----------------------------------------------------------------*/
256 hasSpilLocnoUptr (symbol * sym, eBBlock * ebp, iCode * ic)
258 return ((sym->usl.spillLoc && !sym->uptr) ? 1 : 0);
261 /*-----------------------------------------------------------------*/
262 /* rematable - will return 1 if the remat flag is set */
263 /*-----------------------------------------------------------------*/
265 rematable (symbol * sym, eBBlock * ebp, iCode * ic)
270 /*-----------------------------------------------------------------*/
271 /* notUsedInRemaining - not used or defined in remain of the block */
272 /*-----------------------------------------------------------------*/
274 notUsedInRemaining (symbol * sym, eBBlock * ebp, iCode * ic)
276 return ((usedInRemaining (operandFromSymbol (sym), ic) ? 0 : 1) &&
277 allDefsOutOfRange (sym->defs, ebp->fSeq, ebp->lSeq));
280 /*-----------------------------------------------------------------*/
281 /* allLRs - return true for all */
282 /*-----------------------------------------------------------------*/
284 allLRs (symbol * sym, eBBlock * ebp, iCode * ic)
289 /*-----------------------------------------------------------------*/
290 /* liveRangesWith - applies function to a given set of live range */
291 /*-----------------------------------------------------------------*/
293 liveRangesWith (bitVect * lrs, int (func) (symbol *, eBBlock *, iCode *),
294 eBBlock * ebp, iCode * ic)
299 if (!lrs || !lrs->size)
302 for (i = 1; i < lrs->size; i++)
305 if (!bitVectBitValue (lrs, i))
308 /* if we don't find it in the live range
309 hash table we are in serious trouble */
310 if (!(sym = hTabItemWithKey (liveRanges, i)))
312 werror (E_INTERNAL_ERROR, __FILE__, __LINE__,
313 "liveRangesWith could not find liveRange");
317 if (func (sym, ebp, ic) && bitVectBitValue (_G.regAssigned, sym->key))
318 addSetHead (&rset, sym);
325 /*-----------------------------------------------------------------*/
326 /* leastUsedLR - given a set determines which is the least used */
327 /*-----------------------------------------------------------------*/
329 leastUsedLR (set * sset)
331 symbol *sym = NULL, *lsym = NULL;
333 sym = lsym = setFirstItem (sset);
338 for (; lsym; lsym = setNextItem (sset))
341 /* if usage is the same then prefer
342 the spill the smaller of the two */
343 if (lsym->used == sym->used)
344 if (getSize (lsym->type) < getSize (sym->type))
348 if (lsym->used < sym->used)
353 setToNull ((void **) &sset);
358 /*-----------------------------------------------------------------*/
359 /* noOverLap - will iterate through the list looking for over lap */
360 /*-----------------------------------------------------------------*/
362 noOverLap (set * itmpStack, symbol * fsym)
367 for (sym = setFirstItem (itmpStack); sym;
368 sym = setNextItem (itmpStack))
370 if (bitVectBitValue(sym->clashes,fsym->key)) return 0;
376 /*-----------------------------------------------------------------*/
377 /* isFree - will return 1 if the a free spil location is found */
378 /*-----------------------------------------------------------------*/
383 V_ARG (symbol **, sloc);
384 V_ARG (symbol *, fsym);
386 /* if already found */
390 /* if it is free && and the itmp assigned to
391 this does not have any overlapping live ranges
392 with the one currently being assigned and
393 the size can be accomodated */
395 noOverLap (sym->usl.itmpStack, fsym) &&
396 getSize (sym->type) >= getSize (fsym->type))
405 /*-----------------------------------------------------------------*/
406 /* spillLRWithPtrReg :- will spil those live ranges which use PTR */
407 /*-----------------------------------------------------------------*/
409 spillLRWithPtrReg (symbol * forSym)
415 if (!_G.regAssigned ||
416 bitVectIsZero (_G.regAssigned))
419 r0 = mcs51_regWithIdx (R0_IDX);
420 r1 = mcs51_regWithIdx (R1_IDX);
422 /* for all live ranges */
423 for (lrsym = hTabFirstItem (liveRanges, &k); lrsym;
424 lrsym = hTabNextItem (liveRanges, &k))
428 /* if no registers assigned to it or spilt */
429 /* if it does not overlap with this then
430 not need to spill it */
432 if (lrsym->isspilt || !lrsym->nRegs ||
433 (lrsym->liveTo < forSym->liveFrom))
436 /* go thru the registers : if it is either
437 r0 or r1 then spil it */
438 for (j = 0; j < lrsym->nRegs; j++)
439 if (lrsym->regs[j] == r0 ||
440 lrsym->regs[j] == r1)
449 /*-----------------------------------------------------------------*/
450 /* createStackSpil - create a location on the stack to spil */
451 /*-----------------------------------------------------------------*/
453 createStackSpil (symbol * sym)
456 int useXstack, model;
460 /* first go try and find a free one that is already
461 existing on the stack */
462 if (applyToSet (_G.stackSpil, isFree, &sloc, sym))
464 /* found a free one : just update & return */
465 sym->usl.spillLoc = sloc;
468 addSetHead (&sloc->usl.itmpStack, sym);
472 /* could not then have to create one , this is the hard part
473 we need to allocate this on the stack : this is really a
474 hack!! but cannot think of anything better at this time */
476 if (sprintf (slocBuffer, "sloc%d", _G.slocNum++) >= sizeof (slocBuffer))
478 fprintf (stderr, "***Internal error: slocBuffer overflowed: %s:%d\n",
483 sloc = newiTemp (slocBuffer);
485 /* set the type to the spilling symbol */
486 sloc->type = copyLinkChain (sym->type);
487 sloc->etype = getSpec (sloc->type);
488 SPEC_SCLS (sloc->etype) = S_DATA;
489 SPEC_EXTR (sloc->etype) = 0;
490 SPEC_STAT (sloc->etype) = 0;
491 SPEC_VOLATILE(sloc->etype) = 0;
492 SPEC_ABSA(sloc->etype) = 0;
494 /* we don't allow it to be allocated`
495 onto the external stack since : so we
496 temporarily turn it off ; we also
497 turn off memory model to prevent
498 the spil from going to the external storage
501 useXstack = options.useXstack;
502 model = options.model;
503 /* noOverlay = options.noOverlay; */
504 /* options.noOverlay = 1; */
505 options.model = options.useXstack = 0;
509 options.useXstack = useXstack;
510 options.model = model;
511 /* options.noOverlay = noOverlay; */
512 sloc->isref = 1; /* to prevent compiler warning */
514 /* if it is on the stack then update the stack */
515 if (IN_STACK (sloc->etype))
517 currFunc->stack += getSize (sloc->type);
518 _G.stackExtend += getSize (sloc->type);
521 _G.dataExtend += getSize (sloc->type);
523 /* add it to the _G.stackSpil set */
524 addSetHead (&_G.stackSpil, sloc);
525 sym->usl.spillLoc = sloc;
528 /* add it to the set of itempStack set
529 of the spill location */
530 addSetHead (&sloc->usl.itmpStack, sym);
534 /*-----------------------------------------------------------------*/
535 /* isSpiltOnStack - returns true if the spil location is on stack */
536 /*-----------------------------------------------------------------*/
538 isSpiltOnStack (symbol * sym)
548 /* if (sym->_G.stackSpil) */
551 if (!sym->usl.spillLoc)
554 etype = getSpec (sym->usl.spillLoc->type);
555 if (IN_STACK (etype))
561 /*-----------------------------------------------------------------*/
562 /* spillThis - spils a specific operand */
563 /*-----------------------------------------------------------------*/
565 spillThis (symbol * sym)
568 /* if this is rematerializable or has a spillLocation
569 we are okay, else we need to create a spillLocation
571 if (!(sym->remat || sym->usl.spillLoc))
572 createStackSpil (sym);
575 /* mark it has spilt & put it in the spilt set */
576 sym->isspilt = sym->spillA = 1;
577 _G.spiltSet = bitVectSetBit (_G.spiltSet, sym->key);
579 bitVectUnSetBit (_G.regAssigned, sym->key);
580 bitVectUnSetBit (_G.totRegAssigned, sym->key);
582 for (i = 0; i < sym->nRegs; i++)
586 freeReg (sym->regs[i]);
590 /* if spilt on stack then free up r0 & r1
591 if they could have been assigned to some
593 if (!mcs51_ptrRegReq && isSpiltOnStack (sym))
596 spillLRWithPtrReg (sym);
599 if (sym->usl.spillLoc && !sym->remat)
600 sym->usl.spillLoc->allocreq++;
604 /*-----------------------------------------------------------------*/
605 /* selectSpil - select a iTemp to spil : rather a simple procedure */
606 /*-----------------------------------------------------------------*/
608 selectSpil (iCode * ic, eBBlock * ebp, symbol * forSym)
610 bitVect *lrcs = NULL;
614 /* get the spillable live ranges */
615 lrcs = computeSpillable (ic);
617 /* get all live ranges that are rematerizable */
618 if ((selectS = liveRangesWith (lrcs, rematable, ebp, ic)))
621 /* return the least used of these */
622 return leastUsedLR (selectS);
625 /* get live ranges with spillLocations in direct space */
626 if ((selectS = liveRangesWith (lrcs, directSpilLoc, ebp, ic)))
628 sym = leastUsedLR (selectS);
629 strcpy (sym->rname, (sym->usl.spillLoc->rname[0] ?
630 sym->usl.spillLoc->rname :
631 sym->usl.spillLoc->name));
633 /* mark it as allocation required */
634 sym->usl.spillLoc->allocreq++;
638 /* if the symbol is local to the block then */
639 if (forSym->liveTo < ebp->lSeq)
642 /* check if there are any live ranges allocated
643 to registers that are not used in this block */
644 if (!_G.blockSpil && (selectS = liveRangesWith (lrcs, notUsedInBlock, ebp, ic)))
646 sym = leastUsedLR (selectS);
647 /* if this is not rematerializable */
656 /* check if there are any live ranges that not
657 used in the remainder of the block */
658 if (!_G.blockSpil && (selectS = liveRangesWith (lrcs, notUsedInRemaining, ebp, ic)))
660 sym = leastUsedLR (selectS);
673 /* find live ranges with spillocation && not used as pointers */
674 if ((selectS = liveRangesWith (lrcs, hasSpilLocnoUptr, ebp, ic)))
677 sym = leastUsedLR (selectS);
678 /* mark this as allocation required */
679 sym->usl.spillLoc->allocreq++;
683 /* find live ranges with spillocation */
684 if ((selectS = liveRangesWith (lrcs, hasSpilLoc, ebp, ic)))
687 sym = leastUsedLR (selectS);
688 sym->usl.spillLoc->allocreq++;
692 /* couldn't find then we need to create a spil
693 location on the stack , for which one? the least
695 if ((selectS = liveRangesWith (lrcs, noSpilLoc, ebp, ic)))
698 /* return a created spil location */
699 sym = createStackSpil (leastUsedLR (selectS));
700 sym->usl.spillLoc->allocreq++;
704 /* this is an extreme situation we will spill
705 this one : happens very rarely but it does happen */
711 /*-----------------------------------------------------------------*/
712 /* spilSomething - spil some variable & mark registers as free */
713 /*-----------------------------------------------------------------*/
715 spilSomething (iCode * ic, eBBlock * ebp, symbol * forSym)
720 /* get something we can spil */
721 ssym = selectSpil (ic, ebp, forSym);
723 /* mark it as spilt */
724 ssym->isspilt = ssym->spillA = 1;
725 _G.spiltSet = bitVectSetBit (_G.spiltSet, ssym->key);
727 /* mark it as not register assigned &
728 take it away from the set */
729 bitVectUnSetBit (_G.regAssigned, ssym->key);
730 bitVectUnSetBit (_G.totRegAssigned, ssym->key);
732 /* mark the registers as free */
733 for (i = 0; i < ssym->nRegs; i++)
735 freeReg (ssym->regs[i]);
737 /* if spilt on stack then free up r0 & r1
738 if they could have been assigned to as gprs */
739 if (!mcs51_ptrRegReq && isSpiltOnStack (ssym))
742 spillLRWithPtrReg (ssym);
745 /* if this was a block level spil then insert push & pop
746 at the start & end of block respectively */
749 iCode *nic = newiCode (IPUSH, operandFromSymbol (ssym), NULL);
750 /* add push to the start of the block */
751 addiCodeToeBBlock (ebp, nic, (ebp->sch->op == LABEL ?
752 ebp->sch->next : ebp->sch));
753 nic = newiCode (IPOP, operandFromSymbol (ssym), NULL);
754 /* add pop to the end of the block */
755 addiCodeToeBBlock (ebp, nic, NULL);
758 /* if spilt because not used in the remainder of the
759 block then add a push before this instruction and
760 a pop at the end of the block */
761 if (ssym->remainSpil)
764 iCode *nic = newiCode (IPUSH, operandFromSymbol (ssym), NULL);
765 /* add push just before this instruction */
766 addiCodeToeBBlock (ebp, nic, ic);
768 nic = newiCode (IPOP, operandFromSymbol (ssym), NULL);
769 /* add pop to the end of the block */
770 addiCodeToeBBlock (ebp, nic, NULL);
779 /*-----------------------------------------------------------------*/
780 /* getRegPtr - will try for PTR if not a GPR type if not spil */
781 /*-----------------------------------------------------------------*/
783 getRegPtr (iCode * ic, eBBlock * ebp, symbol * sym)
788 /* try for a ptr type */
789 if ((reg = allocReg (REG_PTR)))
792 /* try for gpr type */
793 if ((reg = allocReg (REG_GPR)))
796 /* we have to spil */
797 if (!spilSomething (ic, ebp, sym))
800 /* this looks like an infinite loop but
801 in really selectSpil will abort */
805 /*-----------------------------------------------------------------*/
806 /* getRegGpr - will try for GPR if not spil */
807 /*-----------------------------------------------------------------*/
809 getRegGpr (iCode * ic, eBBlock * ebp, symbol * sym)
814 /* try for gpr type */
815 if ((reg = allocReg (REG_GPR)))
818 if (!mcs51_ptrRegReq)
819 if ((reg = allocReg (REG_PTR)))
822 /* we have to spil */
823 if (!spilSomething (ic, ebp, sym))
826 /* this looks like an infinite loop but
827 in really selectSpil will abort */
831 /*-----------------------------------------------------------------*/
832 /* getRegPtrNoSpil - get it cannot split */
833 /*-----------------------------------------------------------------*/
834 static regs *getRegPtrNoSpil()
838 /* try for a ptr type */
839 if ((reg = allocReg (REG_PTR)))
842 /* try for gpr type */
843 if ((reg = allocReg (REG_GPR)))
848 /* just to make the compiler happy */
852 /*-----------------------------------------------------------------*/
853 /* getRegGprNoSpil - get it cannot split */
854 /*-----------------------------------------------------------------*/
855 static regs *getRegGprNoSpil()
859 if ((reg = allocReg (REG_GPR)))
862 if (!mcs51_ptrRegReq)
863 if ((reg = allocReg (REG_PTR)))
868 /* just to make the compiler happy */
872 /*-----------------------------------------------------------------*/
873 /* symHasReg - symbol has a given register */
874 /*-----------------------------------------------------------------*/
876 symHasReg (symbol * sym, regs * reg)
880 for (i = 0; i < sym->nRegs; i++)
881 if (sym->regs[i] == reg)
887 /*-----------------------------------------------------------------*/
888 /* deassignLRs - check the live to and if they have registers & are */
889 /* not spilt then free up the registers */
890 /*-----------------------------------------------------------------*/
892 deassignLRs (iCode * ic, eBBlock * ebp)
898 for (sym = hTabFirstItem (liveRanges, &k); sym;
899 sym = hTabNextItem (liveRanges, &k))
903 /* if it does not end here */
904 if (sym->liveTo > ic->seq)
907 /* if it was spilt on stack then we can
908 mark the stack spil location as free */
913 sym->usl.spillLoc->isFree = 1;
919 if (!bitVectBitValue (_G.regAssigned, sym->key))
922 /* special case check if this is an IFX &
923 the privious one was a pop and the
924 previous one was not spilt then keep track
926 if (ic->op == IFX && ic->prev &&
927 ic->prev->op == IPOP &&
928 !ic->prev->parmPush &&
929 !OP_SYMBOL (IC_LEFT (ic->prev))->isspilt)
930 psym = OP_SYMBOL (IC_LEFT (ic->prev));
936 bitVectUnSetBit (_G.regAssigned, sym->key);
938 /* if the result of this one needs registers
939 and does not have it then assign it right
941 if (IC_RESULT (ic) &&
942 !(SKIP_IC2 (ic) || /* not a special icode */
943 ic->op == JUMPTABLE ||
949 (result = OP_SYMBOL (IC_RESULT (ic))) && /* has a result */
950 result->liveTo > ic->seq && /* and will live beyond this */
951 result->liveTo <= ebp->lSeq && /* does not go beyond this block */
952 result->regType == sym->regType && /* same register types */
953 result->nRegs && /* which needs registers */
954 !result->isspilt && /* and does not already have them */
956 !bitVectBitValue (_G.regAssigned, result->key) &&
957 /* the number of free regs + number of regs in this LR
958 can accomodate the what result Needs */
959 ((nfreeRegsType (result->regType) +
960 sym->nRegs) >= result->nRegs)
964 for (i = 0; i < result->nRegs; i++)
966 result->regs[i] = sym->regs[i];
968 result->regs[i] = getRegGpr (ic, ebp, result);
970 _G.regAssigned = bitVectSetBit (_G.regAssigned, result->key);
971 _G.totRegAssigned = bitVectSetBit (_G.totRegAssigned, result->key);
975 /* free the remaining */
976 for (; i < sym->nRegs; i++)
980 if (!symHasReg (psym, sym->regs[i]))
981 freeReg (sym->regs[i]);
984 freeReg (sym->regs[i]);
991 /*-----------------------------------------------------------------*/
992 /* reassignLR - reassign this to registers */
993 /*-----------------------------------------------------------------*/
995 reassignLR (operand * op)
997 symbol *sym = OP_SYMBOL (op);
1000 /* not spilt any more */
1001 sym->isspilt = sym->spillA = sym->blockSpil = sym->remainSpil = 0;
1002 bitVectUnSetBit (_G.spiltSet, sym->key);
1004 _G.regAssigned = bitVectSetBit (_G.regAssigned, sym->key);
1005 _G.totRegAssigned = bitVectSetBit (_G.totRegAssigned, sym->key);
1009 for (i = 0; i < sym->nRegs; i++)
1010 sym->regs[i]->isFree = 0;
1013 /*-----------------------------------------------------------------*/
1014 /* willCauseSpill - determines if allocating will cause a spill */
1015 /*-----------------------------------------------------------------*/
1017 willCauseSpill (int nr, int rt)
1019 /* first check if there are any avlb registers
1020 of te type required */
1023 /* special case for pointer type
1024 if pointer type not avlb then
1025 check for type gpr */
1026 if (nFreeRegs (rt) >= nr)
1028 if (nFreeRegs (REG_GPR) >= nr)
1033 if (mcs51_ptrRegReq)
1035 if (nFreeRegs (rt) >= nr)
1040 if (nFreeRegs (REG_PTR) +
1041 nFreeRegs (REG_GPR) >= nr)
1046 /* it will cause a spil */
1050 /*-----------------------------------------------------------------*/
1051 /* positionRegs - the allocator can allocate same registers to res- */
1052 /* ult and operand, if this happens make sure they are in the same */
1053 /* position as the operand otherwise chaos results */
1054 /*-----------------------------------------------------------------*/
1056 positionRegs (symbol * result, symbol * opsym)
1058 int count = min (result->nRegs, opsym->nRegs);
1059 int i, j = 0, shared = 0;
1062 /* if the result has been spilt then cannot share */
1067 /* first make sure that they actually share */
1068 for (i = 0; i < count; i++)
1070 for (j = 0; j < count; j++)
1072 if (result->regs[i] == opsym->regs[j] && i != j)
1082 regs *tmp = result->regs[i];
1083 result->regs[i] = result->regs[j];
1084 result->regs[j] = tmp;
1091 /*-----------------------------------------------------------------*/
1092 /* serialRegAssign - serially allocate registers to the variables */
1093 /*-----------------------------------------------------------------*/
1095 serialRegAssign (eBBlock ** ebbs, int count)
1099 /* for all blocks */
1100 for (i = 0; i < count; i++) {
1104 if (ebbs[i]->noPath &&
1105 (ebbs[i]->entryLabel != entryLabel &&
1106 ebbs[i]->entryLabel != returnLabel))
1109 /* of all instructions do */
1110 for (ic = ebbs[i]->sch; ic; ic = ic->next) {
1112 /* if this is an ipop that means some live
1113 range will have to be assigned again */
1115 reassignLR (IC_LEFT (ic));
1117 /* if result is present && is a true symbol */
1118 if (IC_RESULT (ic) && ic->op != IFX &&
1119 IS_TRUE_SYMOP (IC_RESULT (ic)))
1120 OP_SYMBOL (IC_RESULT (ic))->allocreq++;
1122 /* take away registers from live
1123 ranges that end at this instruction */
1124 deassignLRs (ic, ebbs[i]);
1126 /* some don't need registers */
1127 if (SKIP_IC2 (ic) ||
1128 ic->op == JUMPTABLE ||
1132 (IC_RESULT (ic) && POINTER_SET (ic)))
1135 /* now we need to allocate registers
1136 only for the result */
1137 if (IC_RESULT (ic)) {
1138 symbol *sym = OP_SYMBOL (IC_RESULT (ic));
1144 /* if it does not need or is spilt
1145 or is already assigned to registers
1146 or will not live beyond this instructions */
1149 bitVectBitValue (_G.regAssigned, sym->key) ||
1150 sym->liveTo <= ic->seq)
1153 /* if some liverange has been spilt at the block level
1154 and this one live beyond this block then spil this
1156 if (_G.blockSpil && sym->liveTo > ebbs[i]->lSeq) {
1160 /* if trying to allocate this will cause
1161 a spill and there is nothing to spill
1162 or this one is rematerializable then
1164 willCS = willCauseSpill (sym->nRegs, sym->regType);
1165 spillable = computeSpillable (ic);
1166 if (sym->remat || (willCS && bitVectIsZero (spillable))) {
1171 /* if it has a spillocation & is used less than
1172 all other live ranges then spill this */
1174 if (sym->usl.spillLoc) {
1175 symbol *leastUsed = leastUsedLR (liveRangesWith (spillable,
1176 allLRs, ebbs[i], ic));
1177 if (leastUsed && leastUsed->used > sym->used) {
1182 /* if none of the liveRanges have a spillLocation then better
1183 to spill this one than anything else already assigned to registers */
1184 if (liveRangesWith(spillable,noSpilLoc,ebbs[i],ic)) {
1185 /* if this is local to this block then we might find a block spil */
1186 if (!(sym->liveFrom >= ebbs[i]->fSeq && sym->liveTo <= ebbs[i]->lSeq)) {
1193 /* if we need ptr regs for the right side
1195 if (POINTER_GET (ic) && IS_SYMOP (IC_LEFT (ic))
1196 && getSize (OP_SYMBOL (IC_LEFT (ic))->type) <= (unsigned int) PTRSIZE) {
1200 /* else we assign registers to it */
1201 _G.regAssigned = bitVectSetBit (_G.regAssigned, sym->key);
1202 _G.totRegAssigned = bitVectSetBit (_G.totRegAssigned, sym->key);
1204 for (j = 0; j < sym->nRegs; j++) {
1205 if (sym->regType == REG_PTR)
1206 sym->regs[j] = getRegPtr (ic, ebbs[i], sym);
1208 sym->regs[j] = getRegGpr (ic, ebbs[i], sym);
1210 /* if the allocation failed which means
1211 this was spilt then break */
1212 if (!sym->regs[j]) {
1217 /* if it shares registers with operands make sure
1218 that they are in the same position */
1219 if (IC_LEFT (ic) && IS_SYMOP (IC_LEFT (ic)) &&
1220 OP_SYMBOL (IC_LEFT (ic))->nRegs && ic->op != '=') {
1221 positionRegs (OP_SYMBOL (IC_RESULT (ic)),
1222 OP_SYMBOL (IC_LEFT (ic)));
1224 /* do the same for the right operand */
1225 if (IC_RIGHT (ic) && IS_SYMOP (IC_RIGHT (ic)) &&
1226 OP_SYMBOL (IC_RIGHT (ic))->nRegs) {
1227 positionRegs (OP_SYMBOL (IC_RESULT (ic)),
1228 OP_SYMBOL (IC_RIGHT (ic)));
1241 /*-----------------------------------------------------------------*/
1242 /* fillGaps - Try to fill in the Gaps left by Pass1 */
1243 /*-----------------------------------------------------------------*/
1244 static void fillGaps()
1249 if (getenv("DISABLE_FILL_GAPS")) return;
1251 /* look for livernages that was spilt by the allocator */
1252 for (sym = hTabFirstItem(liveRanges,&key) ; sym ;
1253 sym = hTabNextItem(liveRanges,&key)) {
1258 if (!sym->spillA || !sym->clashes || sym->remat) continue ;
1260 /* find the liveRanges this one clashes with, that are
1261 still assigned to registers & mark the registers as used*/
1262 for ( i = 0 ; i < sym->clashes->size ; i ++) {
1266 if (bitVectBitValue(sym->clashes,i) == 0 || /* those that clash with this */
1267 bitVectBitValue(_G.totRegAssigned,i) == 0) /* and are still assigned to registers */
1270 clr = hTabItemWithKey(liveRanges,i);
1273 /* mark these registers as used */
1274 for (k = 0 ; k < clr->nRegs ; k++ )
1275 useReg(clr->regs[k]);
1278 if (willCauseSpill(sym->nRegs,sym->regType)) {
1279 /* NOPE :( clear all registers & and continue */
1284 /* THERE IS HOPE !!!! */
1285 for (i=0; i < sym->nRegs ; i++ ) {
1286 if (sym->regType == REG_PTR)
1287 sym->regs[i] = getRegPtrNoSpil ();
1289 sym->regs[i] = getRegGprNoSpil ();
1292 /* for all its definitions check if the registers
1293 allocated needs positioning NOTE: we can position
1294 only ONCE if more than One positioning required
1297 for (i = 0 ; i < sym->defs->size ; i++ ) {
1298 if (bitVectBitValue(sym->defs,i)) {
1300 if (!(ic = hTabItemWithKey(iCodehTab,i))) continue ;
1301 if (SKIP_IC(ic)) continue;
1302 assert(isSymbolEqual(sym,OP_SYMBOL(IC_RESULT(ic)))); /* just making sure */
1303 /* if left is assigned to registers */
1304 if (IS_SYMOP(IC_LEFT(ic)) &&
1305 bitVectBitValue(_G.totRegAssigned,OP_SYMBOL(IC_LEFT(ic))->key)) {
1306 pdone += positionRegs(sym,OP_SYMBOL(IC_LEFT(ic)));
1308 if (IS_SYMOP(IC_RIGHT(ic)) &&
1309 bitVectBitValue(_G.totRegAssigned,OP_SYMBOL(IC_RIGHT(ic))->key)) {
1310 pdone += positionRegs(sym,OP_SYMBOL(IC_RIGHT(ic)));
1312 if (pdone > 1) break;
1315 for (i = 0 ; i < sym->uses->size ; i++ ) {
1316 if (bitVectBitValue(sym->uses,i)) {
1318 if (!(ic = hTabItemWithKey(iCodehTab,i))) continue ;
1319 if (SKIP_IC(ic)) continue;
1320 if (!IS_ASSIGN_ICODE(ic)) continue ;
1322 /* if result is assigned to registers */
1323 if (IS_SYMOP(IC_RESULT(ic)) &&
1324 bitVectBitValue(_G.totRegAssigned,OP_SYMBOL(IC_RESULT(ic))->key)) {
1325 pdone += positionRegs(sym,OP_SYMBOL(IC_RESULT(ic)));
1327 if (pdone > 1) break;
1330 /* had to position more than once GIVE UP */
1332 /* UNDO all the changes we made to try this */
1334 for (i=0; i < sym->nRegs ; i++ ) {
1335 sym->regs[i] = NULL;
1338 D(printf ("Fill Gap gave up due to positioning for %s in function %s\n",sym->name, currFunc ? currFunc->name : "UNKNOWN"));
1341 D(printf ("FILLED GAP for %s in function %s\n",sym->name, currFunc ? currFunc->name : "UNKNOWN"));
1342 _G.totRegAssigned = bitVectSetBit(_G.totRegAssigned,sym->key);
1343 sym->isspilt = sym->spillA = 0 ;
1344 sym->usl.spillLoc->allocreq--;
1349 /*-----------------------------------------------------------------*/
1350 /* rUmaskForOp :- returns register mask for an operand */
1351 /*-----------------------------------------------------------------*/
1353 mcs51_rUmaskForOp (operand * op)
1359 /* only temporaries are assigned registers */
1363 sym = OP_SYMBOL (op);
1365 /* if spilt or no registers assigned to it
1367 if (sym->isspilt || !sym->nRegs)
1370 rumask = newBitVect (mcs51_nRegs);
1372 for (j = 0; j < sym->nRegs; j++)
1374 rumask = bitVectSetBit (rumask,
1375 sym->regs[j]->rIdx);
1381 /*-----------------------------------------------------------------*/
1382 /* regsUsedIniCode :- returns bit vector of registers used in iCode */
1383 /*-----------------------------------------------------------------*/
1385 regsUsedIniCode (iCode * ic)
1387 bitVect *rmask = newBitVect (mcs51_nRegs);
1389 /* do the special cases first */
1392 rmask = bitVectUnion (rmask,
1393 mcs51_rUmaskForOp (IC_COND (ic)));
1397 /* for the jumptable */
1398 if (ic->op == JUMPTABLE)
1400 rmask = bitVectUnion (rmask,
1401 mcs51_rUmaskForOp (IC_JTCOND (ic)));
1406 /* of all other cases */
1408 rmask = bitVectUnion (rmask,
1409 mcs51_rUmaskForOp (IC_LEFT (ic)));
1413 rmask = bitVectUnion (rmask,
1414 mcs51_rUmaskForOp (IC_RIGHT (ic)));
1417 rmask = bitVectUnion (rmask,
1418 mcs51_rUmaskForOp (IC_RESULT (ic)));
1424 /*-----------------------------------------------------------------*/
1425 /* createRegMask - for each instruction will determine the regsUsed */
1426 /*-----------------------------------------------------------------*/
1428 createRegMask (eBBlock ** ebbs, int count)
1432 /* for all blocks */
1433 for (i = 0; i < count; i++)
1437 if (ebbs[i]->noPath &&
1438 (ebbs[i]->entryLabel != entryLabel &&
1439 ebbs[i]->entryLabel != returnLabel))
1442 /* for all instructions */
1443 for (ic = ebbs[i]->sch; ic; ic = ic->next)
1448 if (SKIP_IC2 (ic) || !ic->rlive)
1451 /* first mark the registers used in this
1453 ic->rUsed = regsUsedIniCode (ic);
1454 _G.funcrUsed = bitVectUnion (_G.funcrUsed, ic->rUsed);
1456 /* now create the register mask for those
1457 registers that are in use : this is a
1458 super set of ic->rUsed */
1459 ic->rMask = newBitVect (mcs51_nRegs + 1);
1461 /* for all live Ranges alive at this point */
1462 for (j = 1; j < ic->rlive->size; j++)
1467 /* if not alive then continue */
1468 if (!bitVectBitValue (ic->rlive, j))
1471 /* find the live range we are interested in */
1472 if (!(sym = hTabItemWithKey (liveRanges, j)))
1474 werror (E_INTERNAL_ERROR, __FILE__, __LINE__,
1475 "createRegMask cannot find live range");
1479 /* if no register assigned to it */
1480 if (!sym->nRegs || sym->isspilt)
1483 /* for all the registers allocated to it */
1484 for (k = 0; k < sym->nRegs; k++)
1487 bitVectSetBit (ic->rMask, sym->regs[k]->rIdx);
1493 /*-----------------------------------------------------------------*/
1494 /* rematStr - returns the rematerialized string for a remat var */
1495 /*-----------------------------------------------------------------*/
1497 rematStr (symbol * sym)
1500 iCode *ic = sym->rematiCode;
1505 /* if plus or minus print the right hand side */
1506 if (ic->op == '+' || ic->op == '-')
1508 sprintf (s, "0x%04x %c ", (int) operandLitValue (IC_RIGHT (ic)),
1511 ic = OP_SYMBOL (IC_LEFT (ic))->rematiCode;
1515 /* cast then continue */
1516 if (IS_CAST_ICODE(ic)) {
1517 ic = OP_SYMBOL (IC_RIGHT (ic))->rematiCode;
1520 /* we reached the end */
1521 sprintf (s, "%s", OP_SYMBOL (IC_LEFT (ic))->rname);
1528 /*-----------------------------------------------------------------*/
1529 /* regTypeNum - computes the type & number of registers required */
1530 /*-----------------------------------------------------------------*/
1532 regTypeNum (eBBlock *ebbs)
1538 /* for each live range do */
1539 for (sym = hTabFirstItem (liveRanges, &k); sym;
1540 sym = hTabNextItem (liveRanges, &k))
1543 /* if used zero times then no registers needed */
1544 if ((sym->liveTo - sym->liveFrom) == 0)
1548 /* if the live range is a temporary */
1552 /* if the type is marked as a conditional */
1553 if (sym->regType == REG_CND)
1556 /* if used in return only then we don't
1558 if (sym->ruonly || sym->accuse)
1560 if (IS_AGGREGATE (sym->type) || sym->isptr)
1561 sym->type = aggrToPtr (sym->type, FALSE);
1565 /* if the symbol has only one definition &
1566 that definition is a get_pointer */
1567 if (bitVectnBitsOn (sym->defs) == 1 &&
1568 (ic = hTabItemWithKey (iCodehTab,
1569 bitVectFirstBit (sym->defs))) &&
1572 !IS_BITVAR (sym->etype))
1576 /* and that pointer is remat in data space */
1577 if (OP_SYMBOL (IC_LEFT (ic))->remat &&
1578 !IS_CAST_ICODE(OP_SYMBOL (IC_LEFT (ic))->rematiCode) &&
1579 DCL_TYPE (aggrToPtr (operandType(IC_LEFT(ic)), FALSE)) == POINTER)
1581 /* create a psuedo symbol & force a spil */
1582 symbol *psym = newSymbol (rematStr (OP_SYMBOL (IC_LEFT (ic))), 1);
1583 psym->type = sym->type;
1584 psym->etype = sym->etype;
1585 strcpy (psym->rname, psym->name);
1587 sym->usl.spillLoc = psym;
1588 #if 0 // an alternative fix for bug #480076
1589 /* now this is a useless assignment to itself */
1590 remiCodeFromeBBlock (ebbs, ic);
1592 /* now this really is an assignment to itself, make it so;
1593 it will be optimized out later */
1595 IC_RIGHT(ic)=IC_RESULT(ic);
1601 /* if in data space or idata space then try to
1602 allocate pointer register */
1606 /* if not then we require registers */
1607 sym->nRegs = ((IS_AGGREGATE (sym->type) || sym->isptr) ?
1608 getSize (sym->type = aggrToPtr (sym->type, FALSE)) :
1609 getSize (sym->type));
1613 fprintf (stderr, "allocated more than 4 or 0 registers for type ");
1614 printTypeChain (sym->type, stderr);
1615 fprintf (stderr, "\n");
1618 /* determine the type of register required */
1619 if (sym->nRegs == 1 &&
1620 IS_PTR (sym->type) &&
1622 sym->regType = REG_PTR;
1624 sym->regType = REG_GPR;
1628 /* for the first run we don't provide */
1629 /* registers for true symbols we will */
1630 /* see how things go */
1636 /*-----------------------------------------------------------------*/
1637 /* freeAllRegs - mark all registers as free */
1638 /*-----------------------------------------------------------------*/
1644 for (i = 0; i < mcs51_nRegs; i++)
1645 regs8051[i].isFree = 1;
1648 /*-----------------------------------------------------------------*/
1649 /* deallocStackSpil - this will set the stack pointer back */
1650 /*-----------------------------------------------------------------*/
1652 DEFSETFUNC (deallocStackSpil)
1660 /*-----------------------------------------------------------------*/
1661 /* farSpacePackable - returns the packable icode for far variables */
1662 /*-----------------------------------------------------------------*/
1664 farSpacePackable (iCode * ic)
1668 /* go thru till we find a definition for the
1669 symbol on the right */
1670 for (dic = ic->prev; dic; dic = dic->prev)
1672 /* if the definition is a call then no */
1673 if ((dic->op == CALL || dic->op == PCALL) &&
1674 IC_RESULT (dic)->key == IC_RIGHT (ic)->key)
1679 /* if shift by unknown amount then not */
1680 if ((dic->op == LEFT_OP || dic->op == RIGHT_OP) &&
1681 IC_RESULT (dic)->key == IC_RIGHT (ic)->key)
1684 /* if pointer get and size > 1 */
1685 if (POINTER_GET (dic) &&
1686 getSize (aggrToPtr (operandType (IC_LEFT (dic)), FALSE)) > 1)
1689 if (POINTER_SET (dic) &&
1690 getSize (aggrToPtr (operandType (IC_RESULT (dic)), FALSE)) > 1)
1693 /* if any three is a true symbol in far space */
1694 if (IC_RESULT (dic) &&
1695 IS_TRUE_SYMOP (IC_RESULT (dic)) &&
1696 isOperandInFarSpace (IC_RESULT (dic)))
1699 if (IC_RIGHT (dic) &&
1700 IS_TRUE_SYMOP (IC_RIGHT (dic)) &&
1701 isOperandInFarSpace (IC_RIGHT (dic)) &&
1702 !isOperandEqual (IC_RIGHT (dic), IC_RESULT (ic)))
1705 if (IC_LEFT (dic) &&
1706 IS_TRUE_SYMOP (IC_LEFT (dic)) &&
1707 isOperandInFarSpace (IC_LEFT (dic)) &&
1708 !isOperandEqual (IC_LEFT (dic), IC_RESULT (ic)))
1711 if (isOperandEqual (IC_RIGHT (ic), IC_RESULT (dic)))
1713 if ((dic->op == LEFT_OP ||
1714 dic->op == RIGHT_OP ||
1716 IS_OP_LITERAL (IC_RIGHT (dic)))
1726 /*-----------------------------------------------------------------*/
1727 /* packRegsForAssign - register reduction for assignment */
1728 /*-----------------------------------------------------------------*/
1730 packRegsForAssign (iCode * ic, eBBlock * ebp)
1733 //sym_link *etype = operandType (IC_RIGHT (ic));
1735 if (!IS_ITEMP (IC_RIGHT (ic)) ||
1736 OP_SYMBOL (IC_RIGHT (ic))->isind ||
1737 OP_LIVETO (IC_RIGHT (ic)) > ic->seq
1738 /* why? || IS_BITFIELD (etype) */ )
1743 /* if the true symbol is defined in far space or on stack
1744 then we should not since this will increase register pressure */
1745 if (isOperandInFarSpace(IC_RESULT(ic)) && !farSpacePackable(ic)) {
1749 /* find the definition of iTempNN scanning backwards if we find a
1750 a use of the true symbol in before we find the definition then
1752 for (dic = ic->prev; dic; dic = dic->prev)
1754 /* if there is a function call then don't pack it */
1755 if ((dic->op == CALL || dic->op == PCALL))
1764 if (IS_TRUE_SYMOP (IC_RESULT (dic)) &&
1765 IS_OP_VOLATILE (IC_RESULT (dic)))
1771 if (IS_SYMOP (IC_RESULT (dic)) &&
1772 IC_RESULT (dic)->key == IC_RIGHT (ic)->key)
1774 if (POINTER_SET (dic))
1780 if (IS_SYMOP (IC_RIGHT (dic)) &&
1781 (IC_RIGHT (dic)->key == IC_RESULT (ic)->key ||
1782 IC_RIGHT (dic)->key == IC_RIGHT (ic)->key))
1788 if (IS_SYMOP (IC_LEFT (dic)) &&
1789 (IC_LEFT (dic)->key == IC_RESULT (ic)->key ||
1790 IC_LEFT (dic)->key == IC_RIGHT (ic)->key))
1796 if (POINTER_SET (dic) &&
1797 IC_RESULT (dic)->key == IC_RESULT (ic)->key)
1805 return 0; /* did not find */
1807 /* if assignment then check that right is not a bit */
1808 if (ASSIGNMENT (dic) && !POINTER_SET (dic))
1810 sym_link *etype = operandType (IC_RIGHT (dic));
1811 if (IS_BITFIELD (etype))
1814 /* if the result is on stack or iaccess then it must be
1815 the same atleast one of the operands */
1816 if (OP_SYMBOL (IC_RESULT (ic))->onStack ||
1817 OP_SYMBOL (IC_RESULT (ic))->iaccess)
1820 /* the operation has only one symbol
1821 operator then we can pack */
1822 if ((IC_LEFT (dic) && !IS_SYMOP (IC_LEFT (dic))) ||
1823 (IC_RIGHT (dic) && !IS_SYMOP (IC_RIGHT (dic))))
1826 if (!((IC_LEFT (dic) &&
1827 IC_RESULT (ic)->key == IC_LEFT (dic)->key) ||
1829 IC_RESULT (ic)->key == IC_RIGHT (dic)->key)))
1833 /* found the definition */
1834 /* replace the result with the result of */
1835 /* this assignment and remove this assignment */
1836 bitVectUnSetBit(OP_SYMBOL(IC_RESULT(dic))->defs,dic->key);
1837 IC_RESULT (dic) = IC_RESULT (ic);
1839 if (IS_ITEMP (IC_RESULT (dic)) && OP_SYMBOL (IC_RESULT (dic))->liveFrom > dic->seq)
1841 OP_SYMBOL (IC_RESULT (dic))->liveFrom = dic->seq;
1843 /* delete from liverange table also
1844 delete from all the points inbetween and the new
1846 for (sic = dic; sic != ic; sic = sic->next)
1848 bitVectUnSetBit (sic->rlive, IC_RESULT (ic)->key);
1849 if (IS_ITEMP (IC_RESULT (dic)))
1850 bitVectSetBit (sic->rlive, IC_RESULT (dic)->key);
1853 remiCodeFromeBBlock (ebp, ic);
1854 bitVectUnSetBit(OP_SYMBOL(IC_RESULT(ic))->defs,ic->key);
1855 hTabDeleteItem (&iCodehTab, ic->key, ic, DELETE_ITEM, NULL);
1856 OP_DEFS (IC_RESULT (dic)) = bitVectSetBit (OP_DEFS (IC_RESULT (dic)), dic->key);
1861 /*-----------------------------------------------------------------*/
1862 /* findAssignToSym : scanning backwards looks for first assig found */
1863 /*-----------------------------------------------------------------*/
1865 findAssignToSym (operand * op, iCode * ic)
1869 for (dic = ic->prev; dic; dic = dic->prev)
1872 /* if definition by assignment */
1873 if (dic->op == '=' &&
1874 !POINTER_SET (dic) &&
1875 IC_RESULT (dic)->key == op->key
1876 /* && IS_TRUE_SYMOP(IC_RIGHT(dic)) */
1880 /* we are interested only if defined in far space */
1881 /* or in stack space in case of + & - */
1883 /* if assigned to a non-symbol then return
1885 if (!IS_SYMOP (IC_RIGHT (dic)))
1888 /* if the symbol is in far space then
1890 if (isOperandInFarSpace (IC_RIGHT (dic)))
1893 /* for + & - operations make sure that
1894 if it is on the stack it is the same
1895 as one of the three operands */
1896 if ((ic->op == '+' || ic->op == '-') &&
1897 OP_SYMBOL (IC_RIGHT (dic))->onStack)
1900 if (IC_RESULT (ic)->key != IC_RIGHT (dic)->key &&
1901 IC_LEFT (ic)->key != IC_RIGHT (dic)->key &&
1902 IC_RIGHT (ic)->key != IC_RIGHT (dic)->key)
1910 /* if we find an usage then we cannot delete it */
1911 if (IC_LEFT (dic) && IC_LEFT (dic)->key == op->key)
1914 if (IC_RIGHT (dic) && IC_RIGHT (dic)->key == op->key)
1917 if (POINTER_SET (dic) && IC_RESULT (dic)->key == op->key)
1921 /* now make sure that the right side of dic
1922 is not defined between ic & dic */
1925 iCode *sic = dic->next;
1927 for (; sic != ic; sic = sic->next)
1928 if (IC_RESULT (sic) &&
1929 IC_RESULT (sic)->key == IC_RIGHT (dic)->key)
1938 /*-----------------------------------------------------------------*/
1939 /* packRegsForSupport :- reduce some registers for support calls */
1940 /*-----------------------------------------------------------------*/
1942 packRegsForSupport (iCode * ic, eBBlock * ebp)
1947 /* for the left & right operand :- look to see if the
1948 left was assigned a true symbol in far space in that
1949 case replace them */
1951 if (IS_ITEMP (IC_LEFT (ic)) &&
1952 OP_SYMBOL (IC_LEFT (ic))->liveTo <= ic->seq)
1954 dic = findAssignToSym (IC_LEFT (ic), ic);
1959 /* found it we need to remove it from the
1961 for (sic = dic; sic != ic; sic = sic->next) {
1962 bitVectUnSetBit (sic->rlive, IC_LEFT (ic)->key);
1963 sic->rlive = bitVectSetBit (sic->rlive, IC_RIGHT (dic)->key);
1966 OP_SYMBOL(IC_LEFT (ic))=OP_SYMBOL(IC_RIGHT (dic));
1967 OP_SYMBOL(IC_LEFT(ic))->liveTo = ic->seq;
1968 IC_LEFT (ic)->key = OP_SYMBOL(IC_RIGHT (dic))->key;
1969 remiCodeFromeBBlock (ebp, dic);
1970 bitVectUnSetBit(OP_SYMBOL(IC_RESULT(dic))->defs,dic->key);
1971 hTabDeleteItem (&iCodehTab, dic->key, dic, DELETE_ITEM, NULL);
1975 /* do the same for the right operand */
1978 IS_ITEMP (IC_RIGHT (ic)) &&
1979 OP_SYMBOL (IC_RIGHT (ic))->liveTo <= ic->seq)
1981 iCode *dic = findAssignToSym (IC_RIGHT (ic), ic);
1987 /* if this is a subtraction & the result
1988 is a true symbol in far space then don't pack */
1989 if (ic->op == '-' && IS_TRUE_SYMOP (IC_RESULT (dic)))
1991 sym_link *etype = getSpec (operandType (IC_RESULT (dic)));
1992 if (IN_FARSPACE (SPEC_OCLS (etype)))
1995 /* found it we need to remove it from the
1997 for (sic = dic; sic != ic; sic = sic->next) {
1998 bitVectUnSetBit (sic->rlive, IC_RIGHT (ic)->key);
1999 sic->rlive = bitVectSetBit (sic->rlive, IC_RIGHT (dic)->key);
2002 IC_RIGHT (ic)->operand.symOperand =
2003 IC_RIGHT (dic)->operand.symOperand;
2004 OP_SYMBOL(IC_RIGHT(ic))->liveTo = ic->seq;
2005 IC_RIGHT (ic)->key = IC_RIGHT (dic)->operand.symOperand->key;
2007 remiCodeFromeBBlock (ebp, dic);
2008 bitVectUnSetBit(OP_SYMBOL(IC_RESULT(dic))->defs,dic->key);
2009 hTabDeleteItem (&iCodehTab, dic->key, dic, DELETE_ITEM, NULL);
2016 #define IS_OP_RUONLY(x) (x && IS_SYMOP(x) && OP_SYMBOL(x)->ruonly)
2019 /*-----------------------------------------------------------------*/
2020 /* packRegsForOneuse : - will reduce some registers for single Use */
2021 /*-----------------------------------------------------------------*/
2023 packRegsForOneuse (iCode * ic, operand * op, eBBlock * ebp)
2028 /* if returning a literal then do nothing */
2032 /* only upto 2 bytes since we cannot predict
2033 the usage of b, & acc */
2034 if (getSize (operandType (op)) > (fReturnSizeMCS51 - 2))
2037 if (ic->op != RETURN &&
2039 !POINTER_SET (ic) &&
2043 if (ic->op == SEND && ic->argreg != 1) return NULL;
2045 /* this routine will mark the a symbol as used in one
2046 instruction use only && if the defintion is local
2047 (ie. within the basic block) && has only one definition &&
2048 that definiion is either a return value from a
2049 function or does not contain any variables in
2051 uses = bitVectCopy (OP_USES (op));
2052 bitVectUnSetBit (uses, ic->key); /* take away this iCode */
2053 if (!bitVectIsZero (uses)) /* has other uses */
2056 /* if it has only one defintion */
2057 if (bitVectnBitsOn (OP_DEFS (op)) > 1)
2058 return NULL; /* has more than one definition */
2060 /* get that definition */
2062 hTabItemWithKey (iCodehTab,
2063 bitVectFirstBit (OP_DEFS (op)))))
2066 /* if that only usage is a cast */
2067 if (dic->op == CAST) {
2068 /* to a bigger type */
2069 if (getSize(OP_SYM_TYPE(IC_RESULT(dic))) >
2070 getSize(OP_SYM_TYPE(IC_RIGHT(dic)))) {
2071 /* than we can not, since we cannot predict the usage of b & acc */
2076 /* found the definition now check if it is local */
2077 if (dic->seq < ebp->fSeq ||
2078 dic->seq > ebp->lSeq)
2079 return NULL; /* non-local */
2081 /* now check if it is the return from
2083 if (dic->op == CALL || dic->op == PCALL)
2085 if (ic->op != SEND && ic->op != RETURN &&
2086 !POINTER_SET(ic) && !POINTER_GET(ic))
2088 OP_SYMBOL (op)->ruonly = 1;
2095 /* otherwise check that the definition does
2096 not contain any symbols in far space */
2097 if (isOperandInFarSpace (IC_LEFT (dic)) ||
2098 isOperandInFarSpace (IC_RIGHT (dic)) ||
2099 IS_OP_RUONLY (IC_LEFT (ic)) ||
2100 IS_OP_RUONLY (IC_RIGHT (ic)))
2105 /* if pointer set then make sure the pointer
2107 if (POINTER_SET (dic) &&
2108 !IS_DATA_PTR (aggrToPtr (operandType (IC_RESULT (dic)), FALSE)))
2111 if (POINTER_GET (dic) &&
2112 !IS_DATA_PTR (aggrToPtr (operandType (IC_LEFT (dic)), FALSE)))
2117 /* also make sure the intervenening instructions
2118 don't have any thing in far space */
2119 for (dic = dic->next; dic && dic != ic && sic != ic; dic = dic->next)
2122 /* if there is an intervening function call then no */
2123 if (dic->op == CALL || dic->op == PCALL)
2125 /* if pointer set then make sure the pointer
2127 if (POINTER_SET (dic) &&
2128 !IS_DATA_PTR (aggrToPtr (operandType (IC_RESULT (dic)), FALSE)))
2131 if (POINTER_GET (dic) &&
2132 !IS_DATA_PTR (aggrToPtr (operandType (IC_LEFT (dic)), FALSE)))
2135 /* if address of & the result is remat the okay */
2136 if (dic->op == ADDRESS_OF &&
2137 OP_SYMBOL (IC_RESULT (dic))->remat)
2140 /* if operand has size of three or more & this
2141 operation is a '*','/' or '%' then 'b' may
2143 if ((dic->op == '%' || dic->op == '/' || dic->op == '*') &&
2144 getSize (operandType (op)) >= 3)
2147 /* if left or right or result is in far space */
2148 if (isOperandInFarSpace (IC_LEFT (dic)) ||
2149 isOperandInFarSpace (IC_RIGHT (dic)) ||
2150 isOperandInFarSpace (IC_RESULT (dic)) ||
2151 IS_OP_RUONLY (IC_LEFT (dic)) ||
2152 IS_OP_RUONLY (IC_RIGHT (dic)) ||
2153 IS_OP_RUONLY (IC_RESULT (dic)))
2157 /* if left or right or result is on stack */
2158 if (isOperandOnStack(IC_LEFT(dic)) ||
2159 isOperandOnStack(IC_RIGHT(dic)) ||
2160 isOperandOnStack(IC_RESULT(dic))) {
2165 OP_SYMBOL (op)->ruonly = 1;
2170 /*-----------------------------------------------------------------*/
2171 /* isBitwiseOptimizable - requirements of JEAN LOUIS VERN */
2172 /*-----------------------------------------------------------------*/
2174 isBitwiseOptimizable (iCode * ic)
2176 sym_link *ltype = getSpec (operandType (IC_LEFT (ic)));
2177 sym_link *rtype = getSpec (operandType (IC_RIGHT (ic)));
2179 /* bitwise operations are considered optimizable
2180 under the following conditions (Jean-Louis VERN)
2192 if (IS_LITERAL(rtype) ||
2193 (IS_BITVAR (ltype) && IN_BITSPACE (SPEC_OCLS (ltype))))
2199 /*-----------------------------------------------------------------*/
2200 /* packRegsForAccUse - pack registers for acc use */
2201 /*-----------------------------------------------------------------*/
2203 packRegsForAccUse (iCode * ic)
2207 /* if this is an aggregate, e.g. a one byte char array */
2208 if (IS_AGGREGATE(operandType(IC_RESULT(ic)))) {
2212 /* if we are calling a reentrant function that has stack parameters */
2213 if (ic->op == CALL &&
2214 IFFUNC_ISREENT(operandType(IC_LEFT(ic))) &&
2215 FUNC_HASSTACKPARM(operandType(IC_LEFT(ic))))
2218 if (ic->op == PCALL &&
2219 IFFUNC_ISREENT(operandType(IC_LEFT(ic))->next) &&
2220 FUNC_HASSTACKPARM(operandType(IC_LEFT(ic))->next))
2223 /* if + or - then it has to be one byte result */
2224 if ((ic->op == '+' || ic->op == '-')
2225 && getSize (operandType (IC_RESULT (ic))) > 1)
2228 /* if shift operation make sure right side is not a literal */
2229 if (ic->op == RIGHT_OP &&
2230 (isOperandLiteral (IC_RIGHT (ic)) ||
2231 getSize (operandType (IC_RESULT (ic))) > 1))
2234 if (ic->op == LEFT_OP &&
2235 (isOperandLiteral (IC_RIGHT (ic)) ||
2236 getSize (operandType (IC_RESULT (ic))) > 1))
2239 if (IS_BITWISE_OP (ic) &&
2240 getSize (operandType (IC_RESULT (ic))) > 1)
2244 /* has only one definition */
2245 if (bitVectnBitsOn (OP_DEFS (IC_RESULT (ic))) > 1)
2248 /* has only one use */
2249 if (bitVectnBitsOn (OP_USES (IC_RESULT (ic))) > 1)
2252 /* and the usage immediately follows this iCode */
2253 if (!(uic = hTabItemWithKey (iCodehTab,
2254 bitVectFirstBit (OP_USES (IC_RESULT (ic))))))
2257 if (ic->next != uic)
2260 /* if it is a conditional branch then we definitely can */
2264 if (uic->op == JUMPTABLE)
2267 /* if the usage is not is an assignment
2268 or an arithmetic / bitwise / shift operation then not */
2269 if (POINTER_SET (uic) &&
2270 getSize (aggrToPtr (operandType (IC_RESULT (uic)), FALSE)) > 1)
2273 if (uic->op != '=' &&
2274 !IS_ARITHMETIC_OP (uic) &&
2275 !IS_BITWISE_OP (uic) &&
2276 uic->op != LEFT_OP &&
2277 uic->op != RIGHT_OP)
2280 /* if used in ^ operation then make sure right is not a
2282 if (uic->op == '^' && isOperandLiteral (IC_RIGHT (uic)))
2285 /* if shift operation make sure right side is not a literal */
2286 if (uic->op == RIGHT_OP &&
2287 (isOperandLiteral (IC_RIGHT (uic)) ||
2288 getSize (operandType (IC_RESULT (uic))) > 1))
2291 if (uic->op == LEFT_OP &&
2292 (isOperandLiteral (IC_RIGHT (uic)) ||
2293 getSize (operandType (IC_RESULT (uic))) > 1))
2296 /* make sure that the result of this icode is not on the
2297 stack, since acc is used to compute stack offset */
2299 if (IS_TRUE_SYMOP (IC_RESULT (uic)) &&
2300 OP_SYMBOL (IC_RESULT (uic))->onStack)
2303 if (isOperandOnStack(IC_RESULT(uic)))
2307 /* if either one of them in far space then we cannot */
2308 if ((IS_TRUE_SYMOP (IC_LEFT (uic)) &&
2309 isOperandInFarSpace (IC_LEFT (uic))) ||
2310 (IS_TRUE_SYMOP (IC_RIGHT (uic)) &&
2311 isOperandInFarSpace (IC_RIGHT (uic))))
2314 /* if the usage has only one operand then we can */
2315 if (IC_LEFT (uic) == NULL ||
2316 IC_RIGHT (uic) == NULL)
2319 /* make sure this is on the left side if not
2320 a '+' since '+' is commutative */
2321 if (ic->op != '+' &&
2322 IC_LEFT (uic)->key != IC_RESULT (ic)->key)
2326 // this is too dangerous and need further restrictions
2329 /* if one of them is a literal then we can */
2330 if ((IC_LEFT (uic) && IS_OP_LITERAL (IC_LEFT (uic))) ||
2331 (IC_RIGHT (uic) && IS_OP_LITERAL (IC_RIGHT (uic))))
2333 OP_SYMBOL (IC_RESULT (ic))->accuse = 1;
2338 /* if the other one is not on stack then we can */
2339 if (IC_LEFT (uic)->key == IC_RESULT (ic)->key &&
2340 (IS_ITEMP (IC_RIGHT (uic)) ||
2341 (IS_TRUE_SYMOP (IC_RIGHT (uic)) &&
2342 !OP_SYMBOL (IC_RIGHT (uic))->onStack)))
2345 if (IC_RIGHT (uic)->key == IC_RESULT (ic)->key &&
2346 (IS_ITEMP (IC_LEFT (uic)) ||
2347 (IS_TRUE_SYMOP (IC_LEFT (uic)) &&
2348 !OP_SYMBOL (IC_LEFT (uic))->onStack)))
2354 OP_SYMBOL (IC_RESULT (ic))->accuse = 1;
2359 /*-----------------------------------------------------------------*/
2360 /* packForPush - hueristics to reduce iCode for pushing */
2361 /*-----------------------------------------------------------------*/
2363 packForPush (iCode * ic, eBBlock * ebp)
2368 if (ic->op != IPUSH || !IS_ITEMP (IC_LEFT (ic)))
2371 /* must have only definition & one usage */
2372 if (bitVectnBitsOn (OP_DEFS (IC_LEFT (ic))) != 1 ||
2373 bitVectnBitsOn (OP_USES (IC_LEFT (ic))) != 1)
2376 /* find the definition */
2377 if (!(dic = hTabItemWithKey (iCodehTab,
2378 bitVectFirstBit (OP_DEFS (IC_LEFT (ic))))))
2381 if (dic->op != '=' || POINTER_SET (dic))
2384 /* make sure the right side does not have any definitions
2386 dbv = OP_DEFS(IC_RIGHT(dic));
2387 for (lic = ic; lic && lic != dic ; lic = lic->prev) {
2388 if (bitVectBitValue(dbv,lic->key))
2391 /* make sure they have the same type */
2393 sym_link *itype=operandType(IC_LEFT(ic));
2394 sym_link *ditype=operandType(IC_RIGHT(dic));
2396 if (SPEC_USIGN(itype)!=SPEC_USIGN(ditype) ||
2397 SPEC_LONG(itype)!=SPEC_LONG(ditype))
2400 /* extend the live range of replaced operand if needed */
2401 if (OP_SYMBOL(IC_RIGHT(dic))->liveTo < ic->seq) {
2402 OP_SYMBOL(IC_RIGHT(dic))->liveTo = ic->seq;
2404 /* we now we know that it has one & only one def & use
2405 and the that the definition is an assignment */
2406 IC_LEFT (ic) = IC_RIGHT (dic);
2408 remiCodeFromeBBlock (ebp, dic);
2409 bitVectUnSetBit(OP_SYMBOL(IC_RESULT(dic))->defs,dic->key);
2410 hTabDeleteItem (&iCodehTab, dic->key, dic, DELETE_ITEM, NULL);
2413 /*-----------------------------------------------------------------*/
2414 /* packRegisters - does some transformations to reduce register */
2416 /*-----------------------------------------------------------------*/
2418 packRegisters (eBBlock * ebp)
2428 /* look for assignments of the form */
2429 /* iTempNN = TRueSym (someoperation) SomeOperand */
2431 /* TrueSym := iTempNN:1 */
2432 for (ic = ebp->sch; ic; ic = ic->next)
2434 /* find assignment of the form TrueSym := iTempNN:1 */
2435 if (ic->op == '=' && !POINTER_SET (ic))
2436 change += packRegsForAssign (ic, ebp);
2443 for (ic = ebp->sch; ic; ic = ic->next)
2445 /* if this is an itemp & result of an address of a true sym
2446 then mark this as rematerialisable */
2447 if (ic->op == ADDRESS_OF &&
2448 IS_ITEMP (IC_RESULT (ic)) &&
2449 IS_TRUE_SYMOP (IC_LEFT (ic)) &&
2450 bitVectnBitsOn (OP_DEFS (IC_RESULT (ic))) == 1 &&
2451 !OP_SYMBOL (IC_LEFT (ic))->onStack)
2454 OP_SYMBOL (IC_RESULT (ic))->remat = 1;
2455 OP_SYMBOL (IC_RESULT (ic))->rematiCode = ic;
2456 OP_SYMBOL (IC_RESULT (ic))->usl.spillLoc = NULL;
2460 /* if straight assignment then carry remat flag if
2461 this is the only definition */
2462 if (ic->op == '=' &&
2463 !POINTER_SET (ic) &&
2464 IS_SYMOP (IC_RIGHT (ic)) &&
2465 OP_SYMBOL (IC_RIGHT (ic))->remat &&
2466 !IS_CAST_ICODE(OP_SYMBOL (IC_RIGHT (ic))->rematiCode) &&
2467 bitVectnBitsOn (OP_SYMBOL (IC_RESULT (ic))->defs) <= 1)
2470 OP_SYMBOL (IC_RESULT (ic))->remat =
2471 OP_SYMBOL (IC_RIGHT (ic))->remat;
2472 OP_SYMBOL (IC_RESULT (ic))->rematiCode =
2473 OP_SYMBOL (IC_RIGHT (ic))->rematiCode;
2476 /* if cast to a generic pointer & the pointer being
2477 cast is remat, then we can remat this cast as well */
2478 if (ic->op == CAST &&
2479 IS_SYMOP(IC_RIGHT(ic)) &&
2480 OP_SYMBOL(IC_RIGHT(ic))->remat ) {
2481 sym_link *to_type = operandType(IC_LEFT(ic));
2482 sym_link *from_type = operandType(IC_RIGHT(ic));
2483 if (IS_GENPTR(to_type) && IS_PTR(from_type)) {
2484 OP_SYMBOL (IC_RESULT (ic))->remat = 1;
2485 OP_SYMBOL (IC_RESULT (ic))->rematiCode = ic;
2486 OP_SYMBOL (IC_RESULT (ic))->usl.spillLoc = NULL;
2490 /* if this is a +/- operation with a rematerizable
2491 then mark this as rematerializable as well */
2492 if ((ic->op == '+' || ic->op == '-') &&
2493 (IS_SYMOP (IC_LEFT (ic)) &&
2494 IS_ITEMP (IC_RESULT (ic)) &&
2495 IS_OP_LITERAL (IC_RIGHT (ic))) &&
2496 OP_SYMBOL (IC_LEFT (ic))->remat &&
2497 (!IS_SYMOP (IC_RIGHT (ic)) || !IS_CAST_ICODE(OP_SYMBOL (IC_RIGHT (ic))->rematiCode)) &&
2498 bitVectnBitsOn (OP_DEFS (IC_RESULT (ic))) == 1)
2500 OP_SYMBOL (IC_RESULT (ic))->remat = 1;
2501 OP_SYMBOL (IC_RESULT (ic))->rematiCode = ic;
2502 OP_SYMBOL (IC_RESULT (ic))->usl.spillLoc = NULL;
2505 /* mark the pointer usages */
2506 if (POINTER_SET (ic))
2507 OP_SYMBOL (IC_RESULT (ic))->uptr = 1;
2509 if (POINTER_GET (ic))
2510 OP_SYMBOL (IC_LEFT (ic))->uptr = 1;
2514 /* if we are using a symbol on the stack
2515 then we should say mcs51_ptrRegReq */
2516 if (ic->op == IFX && IS_SYMOP (IC_COND (ic)))
2517 mcs51_ptrRegReq += ((OP_SYMBOL (IC_COND (ic))->onStack ||
2518 OP_SYMBOL (IC_COND (ic))->iaccess) ? 1 : 0);
2519 else if (ic->op == JUMPTABLE && IS_SYMOP (IC_JTCOND (ic)))
2520 mcs51_ptrRegReq += ((OP_SYMBOL (IC_JTCOND (ic))->onStack ||
2521 OP_SYMBOL (IC_JTCOND (ic))->iaccess) ? 1 : 0);
2524 if (IS_SYMOP (IC_LEFT (ic)))
2525 mcs51_ptrRegReq += ((OP_SYMBOL (IC_LEFT (ic))->onStack ||
2526 OP_SYMBOL (IC_LEFT (ic))->iaccess) ? 1 : 0);
2527 if (IS_SYMOP (IC_RIGHT (ic)))
2528 mcs51_ptrRegReq += ((OP_SYMBOL (IC_RIGHT (ic))->onStack ||
2529 OP_SYMBOL (IC_RIGHT (ic))->iaccess) ? 1 : 0);
2530 if (IS_SYMOP (IC_RESULT (ic)))
2531 mcs51_ptrRegReq += ((OP_SYMBOL (IC_RESULT (ic))->onStack ||
2532 OP_SYMBOL (IC_RESULT (ic))->iaccess) ? 1 : 0);
2536 /* if the condition of an if instruction
2537 is defined in the previous instruction and
2538 this is the only usage then
2539 mark the itemp as a conditional */
2540 if ((IS_CONDITIONAL (ic) ||
2541 (IS_BITWISE_OP(ic) && isBitwiseOptimizable (ic))) &&
2542 ic->next && ic->next->op == IFX &&
2543 bitVectnBitsOn (OP_USES(IC_RESULT(ic)))==1 &&
2544 isOperandEqual (IC_RESULT (ic), IC_COND (ic->next)) &&
2545 OP_SYMBOL (IC_RESULT (ic))->liveTo <= ic->next->seq)
2547 OP_SYMBOL (IC_RESULT (ic))->regType = REG_CND;
2551 /* reduce for support function calls */
2552 if (ic->supportRtn || ic->op == '+' || ic->op == '-')
2553 packRegsForSupport (ic, ebp);
2555 /* some cases the redundant moves can
2556 can be eliminated for return statements */
2557 if ((ic->op == RETURN || (ic->op == SEND && ic->argreg == 1)) &&
2558 !isOperandInFarSpace (IC_LEFT (ic)) &&
2559 options.model == MODEL_SMALL) {
2560 if (0 && options.stackAuto) {
2561 /* we should check here if acc will be clobbered for stack
2562 offset calculations */
2564 packRegsForOneuse (ic, IC_LEFT (ic), ebp);
2568 /* if pointer set & left has a size more than
2569 one and right is not in far space */
2570 if (POINTER_SET (ic) &&
2571 !isOperandInFarSpace (IC_RIGHT (ic)) &&
2572 !OP_SYMBOL (IC_RESULT (ic))->remat &&
2573 !IS_OP_RUONLY (IC_RIGHT (ic)) &&
2574 getSize (aggrToPtr (operandType (IC_RESULT (ic)), FALSE)) > 1)
2576 packRegsForOneuse (ic, IC_RESULT (ic), ebp);
2578 /* if pointer get */
2579 if (POINTER_GET (ic) &&
2580 !isOperandInFarSpace (IC_RESULT (ic)) &&
2581 !OP_SYMBOL (IC_LEFT (ic))->remat &&
2582 !IS_OP_RUONLY (IC_RESULT (ic)) &&
2583 getSize (aggrToPtr (operandType (IC_LEFT (ic)), FALSE)) > 1)
2585 packRegsForOneuse (ic, IC_LEFT (ic), ebp);
2588 /* if this is cast for intergral promotion then
2589 check if only use of the definition of the
2590 operand being casted/ if yes then replace
2591 the result of that arithmetic operation with
2592 this result and get rid of the cast */
2595 sym_link *fromType = operandType (IC_RIGHT (ic));
2596 sym_link *toType = operandType (IC_LEFT (ic));
2598 if (IS_INTEGRAL (fromType) && IS_INTEGRAL (toType) &&
2599 getSize (fromType) != getSize (toType) &&
2600 SPEC_USIGN (fromType) == SPEC_USIGN (toType))
2603 iCode *dic = packRegsForOneuse (ic, IC_RIGHT (ic), ebp);
2606 if (IS_ARITHMETIC_OP (dic))
2608 bitVectUnSetBit(OP_SYMBOL(IC_RESULT(dic))->defs,dic->key);
2609 IC_RESULT (dic) = IC_RESULT (ic);
2610 remiCodeFromeBBlock (ebp, ic);
2611 bitVectUnSetBit(OP_SYMBOL(IC_RESULT(ic))->defs,ic->key);
2612 hTabDeleteItem (&iCodehTab, ic->key, ic, DELETE_ITEM, NULL);
2613 OP_DEFS (IC_RESULT (dic)) = bitVectSetBit (OP_DEFS (IC_RESULT (dic)), dic->key);
2617 OP_SYMBOL (IC_RIGHT (ic))->ruonly = 0;
2623 /* if the type from and type to are the same
2624 then if this is the only use then packit */
2625 if (compareType (operandType (IC_RIGHT (ic)),
2626 operandType (IC_LEFT (ic))) == 1)
2628 iCode *dic = packRegsForOneuse (ic, IC_RIGHT (ic), ebp);
2631 bitVectUnSetBit(OP_SYMBOL(IC_RESULT(dic))->defs,dic->key);
2632 IC_RESULT (dic) = IC_RESULT (ic);
2633 remiCodeFromeBBlock (ebp, ic);
2634 bitVectUnSetBit(OP_SYMBOL(IC_RESULT(ic))->defs,ic->key);
2635 hTabDeleteItem (&iCodehTab, ic->key, ic, DELETE_ITEM, NULL);
2636 OP_DEFS (IC_RESULT (dic)) = bitVectSetBit (OP_DEFS (IC_RESULT (dic)), dic->key);
2644 iTempNN := (some variable in farspace) V1
2649 if (ic->op == IPUSH)
2651 packForPush (ic, ebp);
2655 /* pack registers for accumulator use, when the
2656 result of an arithmetic or bit wise operation
2657 has only one use, that use is immediately following
2658 the defintion and the using iCode has only one
2659 operand or has two operands but one is literal &
2660 the result of that operation is not on stack then
2661 we can leave the result of this operation in acc:b
2663 if ((IS_ARITHMETIC_OP (ic)
2664 || IS_CONDITIONAL(ic)
2665 || IS_BITWISE_OP (ic)
2666 || ic->op == LEFT_OP || ic->op == RIGHT_OP || ic->op == CALL
2667 || (ic->op == ADDRESS_OF && isOperandOnStack (IC_LEFT (ic)))
2669 IS_ITEMP (IC_RESULT (ic)) &&
2670 getSize (operandType (IC_RESULT (ic))) <= 2)
2672 packRegsForAccUse (ic);
2676 /*-----------------------------------------------------------------*/
2677 /* assignRegisters - assigns registers to each live range as need */
2678 /*-----------------------------------------------------------------*/
2680 mcs51_assignRegisters (eBBlock ** ebbs, int count)
2685 setToNull ((void *) &_G.funcrUsed);
2686 setToNull ((void *) &_G.totRegAssigned);
2687 mcs51_ptrRegReq = _G.stackExtend = _G.dataExtend = 0;
2690 /* change assignments this will remove some
2691 live ranges reducing some register pressure */
2692 for (i = 0; i < count; i++)
2693 packRegisters (ebbs[i]);
2695 if (options.dump_pack)
2696 dumpEbbsToFileExt (DUMP_PACK, ebbs, count);
2698 /* first determine for each live range the number of
2699 registers & the type of registers required for each */
2702 /* and serially allocate registers */
2703 serialRegAssign (ebbs, count);
2708 /* if stack was extended then tell the user */
2711 /* werror(W_TOOMANY_SPILS,"stack", */
2712 /* _G.stackExtend,currFunc->name,""); */
2718 /* werror(W_TOOMANY_SPILS,"data space", */
2719 /* _G.dataExtend,currFunc->name,""); */
2723 /* after that create the register mask
2724 for each of the instruction */
2725 createRegMask (ebbs, count);
2727 /* redo that offsets for stacked automatic variables */
2728 redoStackOffsets ();
2730 if (options.dump_rassgn)
2732 dumpEbbsToFileExt (DUMP_RASSGN, ebbs, count);
2733 dumpLiveRanges (DUMP_LRANGE, liveRanges);
2736 /* do the overlaysegment stuff SDCCmem.c */
2737 doOverlays (ebbs, count);
2739 /* now get back the chain */
2740 ic = iCodeLabelOptimize (iCodeFromeBBlock (ebbs, count));
2744 /* free up any _G.stackSpil locations allocated */
2745 applyToSet (_G.stackSpil, deallocStackSpil);
2747 setToNull ((void **) &_G.stackSpil);
2748 setToNull ((void **) &_G.spiltSet);
2749 /* mark all registers as free */