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");
1476 fprintf(stderr, "\tmissing live range: key=%d\n", j);
1480 /* if no register assigned to it */
1481 if (!sym->nRegs || sym->isspilt)
1484 /* for all the registers allocated to it */
1485 for (k = 0; k < sym->nRegs; k++)
1488 bitVectSetBit (ic->rMask, sym->regs[k]->rIdx);
1494 /*-----------------------------------------------------------------*/
1495 /* rematStr - returns the rematerialized string for a remat var */
1496 /*-----------------------------------------------------------------*/
1498 rematStr (symbol * sym)
1501 iCode *ic = sym->rematiCode;
1506 /* if plus or minus print the right hand side */
1507 if (ic->op == '+' || ic->op == '-')
1509 sprintf (s, "0x%04x %c ", (int) operandLitValue (IC_RIGHT (ic)),
1512 ic = OP_SYMBOL (IC_LEFT (ic))->rematiCode;
1516 /* cast then continue */
1517 if (IS_CAST_ICODE(ic)) {
1518 ic = OP_SYMBOL (IC_RIGHT (ic))->rematiCode;
1521 /* we reached the end */
1522 sprintf (s, "%s", OP_SYMBOL (IC_LEFT (ic))->rname);
1529 /*-----------------------------------------------------------------*/
1530 /* regTypeNum - computes the type & number of registers required */
1531 /*-----------------------------------------------------------------*/
1533 regTypeNum (eBBlock *ebbs)
1539 /* for each live range do */
1540 for (sym = hTabFirstItem (liveRanges, &k); sym;
1541 sym = hTabNextItem (liveRanges, &k))
1544 /* if used zero times then no registers needed */
1545 if ((sym->liveTo - sym->liveFrom) == 0)
1549 /* if the live range is a temporary */
1553 /* if the type is marked as a conditional */
1554 if (sym->regType == REG_CND)
1557 /* if used in return only then we don't
1559 if (sym->ruonly || sym->accuse)
1561 if (IS_AGGREGATE (sym->type) || sym->isptr)
1562 sym->type = aggrToPtr (sym->type, FALSE);
1566 /* if the symbol has only one definition &
1567 that definition is a get_pointer */
1568 if (bitVectnBitsOn (sym->defs) == 1 &&
1569 (ic = hTabItemWithKey (iCodehTab,
1570 bitVectFirstBit (sym->defs))) &&
1573 !IS_BITVAR (sym->etype))
1577 /* and that pointer is remat in data space */
1578 if (OP_SYMBOL (IC_LEFT (ic))->remat &&
1579 !IS_CAST_ICODE(OP_SYMBOL (IC_LEFT (ic))->rematiCode) &&
1580 DCL_TYPE (aggrToPtr (operandType(IC_LEFT(ic)), FALSE)) == POINTER)
1582 /* create a psuedo symbol & force a spil */
1583 symbol *psym = newSymbol (rematStr (OP_SYMBOL (IC_LEFT (ic))), 1);
1584 psym->type = sym->type;
1585 psym->etype = sym->etype;
1586 strcpy (psym->rname, psym->name);
1588 sym->usl.spillLoc = psym;
1589 #if 0 // an alternative fix for bug #480076
1590 /* now this is a useless assignment to itself */
1591 remiCodeFromeBBlock (ebbs, ic);
1593 /* now this really is an assignment to itself, make it so;
1594 it will be optimized out later */
1596 IC_RIGHT(ic)=IC_RESULT(ic);
1602 /* if in data space or idata space then try to
1603 allocate pointer register */
1607 /* if not then we require registers */
1608 sym->nRegs = ((IS_AGGREGATE (sym->type) || sym->isptr) ?
1609 getSize (sym->type = aggrToPtr (sym->type, FALSE)) :
1610 getSize (sym->type));
1614 fprintf (stderr, "allocated more than 4 or 0 registers for type ");
1615 printTypeChain (sym->type, stderr);
1616 fprintf (stderr, "\n");
1619 /* determine the type of register required */
1620 if (sym->nRegs == 1 &&
1621 IS_PTR (sym->type) &&
1623 sym->regType = REG_PTR;
1625 sym->regType = REG_GPR;
1629 /* for the first run we don't provide */
1630 /* registers for true symbols we will */
1631 /* see how things go */
1637 /*-----------------------------------------------------------------*/
1638 /* freeAllRegs - mark all registers as free */
1639 /*-----------------------------------------------------------------*/
1645 for (i = 0; i < mcs51_nRegs; i++)
1646 regs8051[i].isFree = 1;
1649 /*-----------------------------------------------------------------*/
1650 /* deallocStackSpil - this will set the stack pointer back */
1651 /*-----------------------------------------------------------------*/
1653 DEFSETFUNC (deallocStackSpil)
1661 /*-----------------------------------------------------------------*/
1662 /* farSpacePackable - returns the packable icode for far variables */
1663 /*-----------------------------------------------------------------*/
1665 farSpacePackable (iCode * ic)
1669 /* go thru till we find a definition for the
1670 symbol on the right */
1671 for (dic = ic->prev; dic; dic = dic->prev)
1673 /* if the definition is a call then no */
1674 if ((dic->op == CALL || dic->op == PCALL) &&
1675 IC_RESULT (dic)->key == IC_RIGHT (ic)->key)
1680 /* if shift by unknown amount then not */
1681 if ((dic->op == LEFT_OP || dic->op == RIGHT_OP) &&
1682 IC_RESULT (dic)->key == IC_RIGHT (ic)->key)
1685 /* if pointer get and size > 1 */
1686 if (POINTER_GET (dic) &&
1687 getSize (aggrToPtr (operandType (IC_LEFT (dic)), FALSE)) > 1)
1690 if (POINTER_SET (dic) &&
1691 getSize (aggrToPtr (operandType (IC_RESULT (dic)), FALSE)) > 1)
1694 /* if any three is a true symbol in far space */
1695 if (IC_RESULT (dic) &&
1696 IS_TRUE_SYMOP (IC_RESULT (dic)) &&
1697 isOperandInFarSpace (IC_RESULT (dic)))
1700 if (IC_RIGHT (dic) &&
1701 IS_TRUE_SYMOP (IC_RIGHT (dic)) &&
1702 isOperandInFarSpace (IC_RIGHT (dic)) &&
1703 !isOperandEqual (IC_RIGHT (dic), IC_RESULT (ic)))
1706 if (IC_LEFT (dic) &&
1707 IS_TRUE_SYMOP (IC_LEFT (dic)) &&
1708 isOperandInFarSpace (IC_LEFT (dic)) &&
1709 !isOperandEqual (IC_LEFT (dic), IC_RESULT (ic)))
1712 if (isOperandEqual (IC_RIGHT (ic), IC_RESULT (dic)))
1714 if ((dic->op == LEFT_OP ||
1715 dic->op == RIGHT_OP ||
1717 IS_OP_LITERAL (IC_RIGHT (dic)))
1727 /*-----------------------------------------------------------------*/
1728 /* packRegsForAssign - register reduction for assignment */
1729 /*-----------------------------------------------------------------*/
1731 packRegsForAssign (iCode * ic, eBBlock * ebp)
1734 //sym_link *etype = operandType (IC_RIGHT (ic));
1736 if (!IS_ITEMP (IC_RIGHT (ic)) ||
1737 OP_SYMBOL (IC_RIGHT (ic))->isind ||
1738 OP_LIVETO (IC_RIGHT (ic)) > ic->seq
1739 /* why? || IS_BITFIELD (etype) */ )
1744 /* if the true symbol is defined in far space or on stack
1745 then we should not since this will increase register pressure */
1746 if (isOperandInFarSpace(IC_RESULT(ic)) && !farSpacePackable(ic)) {
1750 /* find the definition of iTempNN scanning backwards if we find a
1751 a use of the true symbol in before we find the definition then
1753 for (dic = ic->prev; dic; dic = dic->prev)
1755 /* if there is a function call then don't pack it */
1756 if ((dic->op == CALL || dic->op == PCALL))
1765 if (IS_TRUE_SYMOP (IC_RESULT (dic)) &&
1766 IS_OP_VOLATILE (IC_RESULT (dic)))
1772 if (IS_SYMOP (IC_RESULT (dic)) &&
1773 IC_RESULT (dic)->key == IC_RIGHT (ic)->key)
1775 if (POINTER_SET (dic))
1781 if (IS_SYMOP (IC_RIGHT (dic)) &&
1782 (IC_RIGHT (dic)->key == IC_RESULT (ic)->key ||
1783 IC_RIGHT (dic)->key == IC_RIGHT (ic)->key))
1789 if (IS_SYMOP (IC_LEFT (dic)) &&
1790 (IC_LEFT (dic)->key == IC_RESULT (ic)->key ||
1791 IC_LEFT (dic)->key == IC_RIGHT (ic)->key))
1797 if (POINTER_SET (dic) &&
1798 IC_RESULT (dic)->key == IC_RESULT (ic)->key)
1806 return 0; /* did not find */
1808 /* if assignment then check that right is not a bit */
1809 if (ASSIGNMENT (dic) && !POINTER_SET (dic))
1811 sym_link *etype = operandType (IC_RIGHT (dic));
1812 if (IS_BITFIELD (etype))
1815 /* if the result is on stack or iaccess then it must be
1816 the same atleast one of the operands */
1817 if (OP_SYMBOL (IC_RESULT (ic))->onStack ||
1818 OP_SYMBOL (IC_RESULT (ic))->iaccess)
1821 /* the operation has only one symbol
1822 operator then we can pack */
1823 if ((IC_LEFT (dic) && !IS_SYMOP (IC_LEFT (dic))) ||
1824 (IC_RIGHT (dic) && !IS_SYMOP (IC_RIGHT (dic))))
1827 if (!((IC_LEFT (dic) &&
1828 IC_RESULT (ic)->key == IC_LEFT (dic)->key) ||
1830 IC_RESULT (ic)->key == IC_RIGHT (dic)->key)))
1834 /* found the definition */
1835 /* replace the result with the result of */
1836 /* this assignment and remove this assignment */
1837 bitVectUnSetBit(OP_SYMBOL(IC_RESULT(dic))->defs,dic->key);
1838 IC_RESULT (dic) = IC_RESULT (ic);
1840 if (IS_ITEMP (IC_RESULT (dic)) && OP_SYMBOL (IC_RESULT (dic))->liveFrom > dic->seq)
1842 OP_SYMBOL (IC_RESULT (dic))->liveFrom = dic->seq;
1844 /* delete from liverange table also
1845 delete from all the points inbetween and the new
1847 for (sic = dic; sic != ic; sic = sic->next)
1849 bitVectUnSetBit (sic->rlive, IC_RESULT (ic)->key);
1850 if (IS_ITEMP (IC_RESULT (dic)))
1851 bitVectSetBit (sic->rlive, IC_RESULT (dic)->key);
1854 remiCodeFromeBBlock (ebp, ic);
1855 bitVectUnSetBit(OP_SYMBOL(IC_RESULT(ic))->defs,ic->key);
1856 hTabDeleteItem (&iCodehTab, ic->key, ic, DELETE_ITEM, NULL);
1857 OP_DEFS_SET ((IC_RESULT (dic)), bitVectSetBit (OP_DEFS (IC_RESULT (dic)), dic->key));
1862 /*------------------------------------------------------------------*/
1863 /* findAssignToSym : scanning backwards looks for first assig found */
1864 /*------------------------------------------------------------------*/
1866 findAssignToSym (operand * op, iCode * ic)
1870 /* This routine is used to find sequences like
1872 ...; (intervening ops don't use iTempAA or modify FOO)
1873 blah = blah + iTempAA;
1875 and eliminate the use of iTempAA, freeing up its register for
1880 for (dic = ic->prev; dic; dic = dic->prev)
1883 /* if definition by assignment */
1884 if (dic->op == '=' &&
1885 !POINTER_SET (dic) &&
1886 IC_RESULT (dic)->key == op->key
1887 /* && IS_TRUE_SYMOP(IC_RIGHT(dic)) */
1889 break; /* found where this temp was defined */
1891 /* if we find an usage then we cannot delete it */
1892 if (IC_LEFT (dic) && IC_LEFT (dic)->key == op->key)
1895 if (IC_RIGHT (dic) && IC_RIGHT (dic)->key == op->key)
1898 if (POINTER_SET (dic) && IC_RESULT (dic)->key == op->key)
1903 return NULL; /* didn't find any assignment to op */
1905 /* we are interested only if defined in far space */
1906 /* or in stack space in case of + & - */
1908 /* if assigned to a non-symbol then don't repack regs */
1909 if (!IS_SYMOP (IC_RIGHT (dic)))
1912 /* if the symbol is volatile then we should not */
1913 if (isOperandVolatile (IC_RIGHT (dic), TRUE))
1915 /* XXX TODO --- should we be passing FALSE to isOperandVolatile()?
1916 What does it mean for an iTemp to be volatile, anyway? Passing
1917 TRUE is more cautious but may prevent possible optimizations */
1919 /* if the symbol is in far space then we should not */
1920 if (isOperandInFarSpace (IC_RIGHT (dic)))
1923 /* for + & - operations make sure that
1924 if it is on the stack it is the same
1925 as one of the three operands */
1926 if ((ic->op == '+' || ic->op == '-') &&
1927 OP_SYMBOL (IC_RIGHT (dic))->onStack)
1930 if (IC_RESULT (ic)->key != IC_RIGHT (dic)->key &&
1931 IC_LEFT (ic)->key != IC_RIGHT (dic)->key &&
1932 IC_RIGHT (ic)->key != IC_RIGHT (dic)->key)
1936 /* now make sure that the right side of dic
1937 is not defined between ic & dic */
1940 iCode *sic = dic->next;
1942 for (; sic != ic; sic = sic->next)
1943 if (IC_RESULT (sic) &&
1944 IC_RESULT (sic)->key == IC_RIGHT (dic)->key)
1951 /*-----------------------------------------------------------------*/
1952 /* reassignAliasedSym - used by packRegsForSupport to replace */
1953 /* redundant iTemp with equivalent symbol */
1954 /*-----------------------------------------------------------------*/
1956 reassignAliasedSym (eBBlock *ebp, iCode *assignment, iCode *use, operand *op)
1959 unsigned oldSymKey, newSymKey;
1961 oldSymKey = op->key;
1962 newSymKey = IC_RIGHT(assignment)->key;
1964 /* only track live ranges of compiler-generated temporaries */
1965 if (!IS_ITEMP(IC_RIGHT(assignment)))
1968 /* update the live-value bitmaps */
1969 for (ic = assignment; ic != use; ic = ic->next) {
1970 bitVectUnSetBit (ic->rlive, oldSymKey);
1972 ic->rlive = bitVectSetBit (ic->rlive, newSymKey);
1975 /* update the sym of the used operand */
1976 OP_SYMBOL(op) = OP_SYMBOL(IC_RIGHT(assignment));
1977 op->key = OP_SYMBOL(op)->key;
1979 /* update the sym's liverange */
1980 if ( OP_LIVETO(op) < ic->seq )
1981 setToRange(op, ic->seq, FALSE);
1983 /* remove the assignment iCode now that its result is unused */
1984 remiCodeFromeBBlock (ebp, assignment);
1985 bitVectUnSetBit(OP_SYMBOL(IC_RESULT(assignment))->defs, assignment->key);
1986 hTabDeleteItem (&iCodehTab, assignment->key, assignment, DELETE_ITEM, NULL);
1990 /*-----------------------------------------------------------------*/
1991 /* packRegsForSupport :- reduce some registers for support calls */
1992 /*-----------------------------------------------------------------*/
1994 packRegsForSupport (iCode * ic, eBBlock * ebp)
1998 /* for the left & right operand :- look to see if the
1999 left was assigned a true symbol in far space in that
2000 case replace them */
2002 if (IS_ITEMP (IC_LEFT (ic)) &&
2003 OP_SYMBOL (IC_LEFT (ic))->liveTo <= ic->seq)
2005 dic = findAssignToSym (IC_LEFT (ic), ic);
2009 /* found it we need to remove it from the block */
2010 reassignAliasedSym (ebp, dic, ic, IC_LEFT(ic));
2015 /* do the same for the right operand */
2016 if (IS_ITEMP (IC_RIGHT (ic)) &&
2017 OP_SYMBOL (IC_RIGHT (ic))->liveTo <= ic->seq)
2019 iCode *dic = findAssignToSym (IC_RIGHT (ic), ic);
2023 /* if this is a subtraction & the result
2024 is a true symbol in far space then don't pack */
2025 if (ic->op == '-' && IS_TRUE_SYMOP (IC_RESULT (dic)))
2027 sym_link *etype = getSpec (operandType (IC_RESULT (dic)));
2028 if (IN_FARSPACE (SPEC_OCLS (etype)))
2031 /* found it we need to remove it from the
2033 reassignAliasedSym (ebp, dic, ic, IC_RIGHT(ic));
2042 #define IS_OP_RUONLY(x) (x && IS_SYMOP(x) && OP_SYMBOL(x)->ruonly)
2045 /*-----------------------------------------------------------------*/
2046 /* packRegsForOneuse : - will reduce some registers for single Use */
2047 /*-----------------------------------------------------------------*/
2049 packRegsForOneuse (iCode * ic, operand * op, eBBlock * ebp)
2054 /* if returning a literal then do nothing */
2058 /* only upto 2 bytes since we cannot predict
2059 the usage of b, & acc */
2060 if (getSize (operandType (op)) > (fReturnSizeMCS51 - 2))
2063 if (ic->op != RETURN &&
2065 !POINTER_SET (ic) &&
2069 if (ic->op == SEND && ic->argreg != 1) return NULL;
2071 /* this routine will mark the a symbol as used in one
2072 instruction use only && if the defintion is local
2073 (ie. within the basic block) && has only one definition &&
2074 that definiion is either a return value from a
2075 function or does not contain any variables in
2077 uses = bitVectCopy (OP_USES (op));
2078 bitVectUnSetBit (uses, ic->key); /* take away this iCode */
2079 if (!bitVectIsZero (uses)) /* has other uses */
2082 /* if it has only one defintion */
2083 if (bitVectnBitsOn (OP_DEFS (op)) > 1)
2084 return NULL; /* has more than one definition */
2086 /* get that definition */
2088 hTabItemWithKey (iCodehTab,
2089 bitVectFirstBit (OP_DEFS (op)))))
2092 /* if that only usage is a cast */
2093 if (dic->op == CAST) {
2094 /* to a bigger type */
2095 if (getSize(OP_SYM_TYPE(IC_RESULT(dic))) >
2096 getSize(OP_SYM_TYPE(IC_RIGHT(dic)))) {
2097 /* than we can not, since we cannot predict the usage of b & acc */
2102 /* found the definition now check if it is local */
2103 if (dic->seq < ebp->fSeq ||
2104 dic->seq > ebp->lSeq)
2105 return NULL; /* non-local */
2107 /* now check if it is the return from
2109 if (dic->op == CALL || dic->op == PCALL)
2111 if (ic->op != SEND && ic->op != RETURN &&
2112 !POINTER_SET(ic) && !POINTER_GET(ic))
2114 OP_SYMBOL (op)->ruonly = 1;
2121 /* otherwise check that the definition does
2122 not contain any symbols in far space */
2123 if (isOperandInFarSpace (IC_LEFT (dic)) ||
2124 isOperandInFarSpace (IC_RIGHT (dic)) ||
2125 IS_OP_RUONLY (IC_LEFT (ic)) ||
2126 IS_OP_RUONLY (IC_RIGHT (ic)))
2131 /* if pointer set then make sure the pointer
2133 if (POINTER_SET (dic) &&
2134 !IS_DATA_PTR (aggrToPtr (operandType (IC_RESULT (dic)), FALSE)))
2137 if (POINTER_GET (dic) &&
2138 !IS_DATA_PTR (aggrToPtr (operandType (IC_LEFT (dic)), FALSE)))
2143 /* also make sure the intervenening instructions
2144 don't have any thing in far space */
2145 for (dic = dic->next; dic && dic != ic && sic != ic; dic = dic->next)
2148 /* if there is an intervening function call then no */
2149 if (dic->op == CALL || dic->op == PCALL)
2151 /* if pointer set then make sure the pointer
2153 if (POINTER_SET (dic) &&
2154 !IS_DATA_PTR (aggrToPtr (operandType (IC_RESULT (dic)), FALSE)))
2157 if (POINTER_GET (dic) &&
2158 !IS_DATA_PTR (aggrToPtr (operandType (IC_LEFT (dic)), FALSE)))
2161 /* if address of & the result is remat the okay */
2162 if (dic->op == ADDRESS_OF &&
2163 OP_SYMBOL (IC_RESULT (dic))->remat)
2166 /* if operand has size of three or more & this
2167 operation is a '*','/' or '%' then 'b' may
2169 if ((dic->op == '%' || dic->op == '/' || dic->op == '*') &&
2170 getSize (operandType (op)) >= 3)
2173 /* if left or right or result is in far space */
2174 if (isOperandInFarSpace (IC_LEFT (dic)) ||
2175 isOperandInFarSpace (IC_RIGHT (dic)) ||
2176 isOperandInFarSpace (IC_RESULT (dic)) ||
2177 IS_OP_RUONLY (IC_LEFT (dic)) ||
2178 IS_OP_RUONLY (IC_RIGHT (dic)) ||
2179 IS_OP_RUONLY (IC_RESULT (dic)))
2183 /* if left or right or result is on stack */
2184 if (isOperandOnStack(IC_LEFT(dic)) ||
2185 isOperandOnStack(IC_RIGHT(dic)) ||
2186 isOperandOnStack(IC_RESULT(dic))) {
2191 OP_SYMBOL (op)->ruonly = 1;
2196 /*-----------------------------------------------------------------*/
2197 /* isBitwiseOptimizable - requirements of JEAN LOUIS VERN */
2198 /*-----------------------------------------------------------------*/
2200 isBitwiseOptimizable (iCode * ic)
2202 sym_link *ltype = getSpec (operandType (IC_LEFT (ic)));
2203 sym_link *rtype = getSpec (operandType (IC_RIGHT (ic)));
2205 /* bitwise operations are considered optimizable
2206 under the following conditions (Jean-Louis VERN)
2218 if (IS_LITERAL(rtype) ||
2219 (IS_BITVAR (ltype) && IN_BITSPACE (SPEC_OCLS (ltype))))
2225 /*-----------------------------------------------------------------*/
2226 /* isCommutativeOp - tests whether this op cares what order its */
2227 /* operands are in */
2228 /*-----------------------------------------------------------------*/
2229 bool isCommutativeOp(unsigned int op)
2231 if (op == '+' || op == '*' || op == EQ_OP ||
2232 op == '^' || op == '|' || op == BITWISEAND)
2238 /*-----------------------------------------------------------------*/
2239 /* operandUsesAcc - determines whether the code generated for this */
2240 /* operand will have to use the accumulator */
2241 /*-----------------------------------------------------------------*/
2242 bool operandUsesAcc(operand *op)
2248 symbol *sym = OP_SYMBOL(op);
2252 return TRUE; /* duh! */
2254 if (IN_STACK(sym->etype) || sym->onStack ||
2255 (SPIL_LOC(op) && SPIL_LOC(op)->onStack))
2256 return TRUE; /* acc is used to calc stack offset */
2261 sym = SPIL_LOC(op); /* if spilled, look at spill location */
2263 return FALSE; /* more checks? */
2267 symspace = SPEC_OCLS(sym->etype);
2269 if (sym->iaccess && symspace->paged)
2270 return TRUE; /* must fetch paged indirect sym via accumulator */
2272 if (IN_BITSPACE(symspace))
2273 return TRUE; /* fetching bit vars uses the accumulator */
2275 if (IN_FARSPACE(symspace) || IN_CODESPACE(symspace))
2276 return TRUE; /* fetched via accumulator and dptr */
2282 /*-----------------------------------------------------------------*/
2283 /* packRegsForAccUse - pack registers for acc use */
2284 /*-----------------------------------------------------------------*/
2286 packRegsForAccUse (iCode * ic)
2290 /* if this is an aggregate, e.g. a one byte char array */
2291 if (IS_AGGREGATE(operandType(IC_RESULT(ic)))) {
2295 /* if we are calling a reentrant function that has stack parameters */
2296 if (ic->op == CALL &&
2297 IFFUNC_ISREENT(operandType(IC_LEFT(ic))) &&
2298 FUNC_HASSTACKPARM(operandType(IC_LEFT(ic))))
2301 if (ic->op == PCALL &&
2302 IFFUNC_ISREENT(operandType(IC_LEFT(ic))->next) &&
2303 FUNC_HASSTACKPARM(operandType(IC_LEFT(ic))->next))
2306 /* if + or - then it has to be one byte result */
2307 if ((ic->op == '+' || ic->op == '-')
2308 && getSize (operandType (IC_RESULT (ic))) > 1)
2311 /* if shift operation make sure right side is not a literal */
2312 if (ic->op == RIGHT_OP &&
2313 (isOperandLiteral (IC_RIGHT (ic)) ||
2314 getSize (operandType (IC_RESULT (ic))) > 1))
2317 if (ic->op == LEFT_OP &&
2318 (isOperandLiteral (IC_RIGHT (ic)) ||
2319 getSize (operandType (IC_RESULT (ic))) > 1))
2322 if (IS_BITWISE_OP (ic) &&
2323 getSize (operandType (IC_RESULT (ic))) > 1)
2327 /* has only one definition */
2328 if (bitVectnBitsOn (OP_DEFS (IC_RESULT (ic))) > 1)
2331 /* has only one use */
2332 if (bitVectnBitsOn (OP_USES (IC_RESULT (ic))) > 1)
2335 /* and the usage immediately follows this iCode */
2336 if (!(uic = hTabItemWithKey (iCodehTab,
2337 bitVectFirstBit (OP_USES (IC_RESULT (ic))))))
2340 if (ic->next != uic)
2343 /* if it is a conditional branch then we definitely can */
2347 if (uic->op == JUMPTABLE)
2350 if (POINTER_SET (uic) &&
2351 getSize (aggrToPtr (operandType (IC_RESULT (uic)), FALSE)) > 1)
2354 /* if the usage is not is an assignment
2355 or an arithmetic / bitwise / shift operation then not */
2356 if (uic->op != '=' &&
2357 !IS_ARITHMETIC_OP (uic) &&
2358 !IS_BITWISE_OP (uic) &&
2359 uic->op != LEFT_OP &&
2360 uic->op != RIGHT_OP)
2363 /* if used in ^ operation then make sure right is not a
2364 literal (WIML: Why is this?) */
2365 if (uic->op == '^' && isOperandLiteral (IC_RIGHT (uic)))
2368 /* if shift operation make sure right side is not a literal */
2369 /* WIML: Why is this? */
2370 if (uic->op == RIGHT_OP &&
2371 (isOperandLiteral (IC_RIGHT (uic)) ||
2372 getSize (operandType (IC_RESULT (uic))) > 1))
2374 if (uic->op == LEFT_OP &&
2375 (isOperandLiteral (IC_RIGHT (uic)) ||
2376 getSize (operandType (IC_RESULT (uic))) > 1))
2379 /* make sure that the result of this icode is not on the
2380 stack, since acc is used to compute stack offset */
2382 if (IS_TRUE_SYMOP (IC_RESULT (uic)) &&
2383 OP_SYMBOL (IC_RESULT (uic))->onStack)
2386 if (isOperandOnStack(IC_RESULT(uic)))
2390 /* if the usage has only one operand then we can */
2391 if (IC_LEFT (uic) == NULL ||
2392 IC_RIGHT (uic) == NULL)
2395 /* if the other operand uses the accumulator then we cannot */
2396 if ( (IC_LEFT(uic)->key == IC_RESULT(ic)->key &&
2397 operandUsesAcc(IC_RIGHT(uic))) ||
2398 (IC_RIGHT(uic)->key == IC_RESULT(ic)->key &&
2399 operandUsesAcc(IC_LEFT(uic))) )
2402 /* make sure this is on the left side if not commutative */
2403 /* except for '-', which has been written to be able to
2404 handle reversed operands */
2405 if (!(isCommutativeOp(ic->op) || ic->op == '-') &&
2406 IC_LEFT (uic)->key != IC_RESULT (ic)->key)
2410 // this is too dangerous and need further restrictions
2413 /* if one of them is a literal then we can */
2414 if ((IC_LEFT (uic) && IS_OP_LITERAL (IC_LEFT (uic))) ||
2415 (IC_RIGHT (uic) && IS_OP_LITERAL (IC_RIGHT (uic))))
2417 OP_SYMBOL (IC_RESULT (ic))->accuse = 1;
2423 OP_SYMBOL (IC_RESULT (ic))->accuse = 1;
2427 /*-----------------------------------------------------------------*/
2428 /* packForPush - hueristics to reduce iCode for pushing */
2429 /*-----------------------------------------------------------------*/
2431 packForPush (iCode * ic, eBBlock ** ebpp, int blockno)
2435 struct eBBlock * ebp=ebpp[blockno];
2437 if (ic->op != IPUSH || !IS_ITEMP (IC_LEFT (ic)))
2440 /* must have only definition & one usage */
2441 if (bitVectnBitsOn (OP_DEFS (IC_LEFT (ic))) != 1 ||
2442 bitVectnBitsOn (OP_USES (IC_LEFT (ic))) != 1)
2445 /* find the definition */
2446 if (!(dic = hTabItemWithKey (iCodehTab,
2447 bitVectFirstBit (OP_DEFS (IC_LEFT (ic))))))
2450 if (dic->op != '=' || POINTER_SET (dic))
2453 if (dic->seq < ebp->fSeq) { // Evelyn did this
2455 for (i=0; i<blockno; i++) {
2456 if (dic->seq >= ebpp[i]->fSeq && dic->seq <= ebpp[i]->lSeq) {
2461 wassert (i!=blockno); // no way to recover from here
2464 if (IS_SYMOP(IC_RIGHT(dic))) {
2465 /* make sure the right side does not have any definitions
2467 dbv = OP_DEFS(IC_RIGHT(dic));
2468 for (lic = ic; lic && lic != dic ; lic = lic->prev) {
2469 if (bitVectBitValue(dbv,lic->key))
2472 /* make sure they have the same type */
2474 sym_link *itype=operandType(IC_LEFT(ic));
2475 sym_link *ditype=operandType(IC_RIGHT(dic));
2477 if (SPEC_USIGN(itype)!=SPEC_USIGN(ditype) ||
2478 SPEC_LONG(itype)!=SPEC_LONG(ditype))
2481 /* extend the live range of replaced operand if needed */
2482 if (OP_SYMBOL(IC_RIGHT(dic))->liveTo < ic->seq) {
2483 OP_SYMBOL(IC_RIGHT(dic))->liveTo = ic->seq;
2485 bitVectUnSetBit(OP_SYMBOL(IC_RESULT(dic))->defs,dic->key);
2488 /* we now we know that it has one & only one def & use
2489 and the that the definition is an assignment */
2490 IC_LEFT (ic) = IC_RIGHT (dic);
2491 remiCodeFromeBBlock (ebp, dic);
2492 hTabDeleteItem (&iCodehTab, dic->key, dic, DELETE_ITEM, NULL);
2495 /*-----------------------------------------------------------------*/
2496 /* packRegisters - does some transformations to reduce register */
2498 /*-----------------------------------------------------------------*/
2500 packRegisters (eBBlock ** ebpp, int blockno)
2504 eBBlock *ebp=ebpp[blockno];
2511 /* look for assignments of the form */
2512 /* iTempNN = TRueSym (someoperation) SomeOperand */
2514 /* TrueSym := iTempNN:1 */
2515 for (ic = ebp->sch; ic; ic = ic->next)
2517 /* find assignment of the form TrueSym := iTempNN:1 */
2518 if (ic->op == '=' && !POINTER_SET (ic))
2519 change += packRegsForAssign (ic, ebp);
2526 for (ic = ebp->sch; ic; ic = ic->next)
2528 /* if this is an itemp & result of an address of a true sym
2529 then mark this as rematerialisable */
2530 if (ic->op == ADDRESS_OF &&
2531 IS_ITEMP (IC_RESULT (ic)) &&
2532 IS_TRUE_SYMOP (IC_LEFT (ic)) &&
2533 bitVectnBitsOn (OP_DEFS (IC_RESULT (ic))) == 1 &&
2534 !OP_SYMBOL (IC_LEFT (ic))->onStack)
2537 OP_SYMBOL (IC_RESULT (ic))->remat = 1;
2538 OP_SYMBOL (IC_RESULT (ic))->rematiCode = ic;
2539 OP_SYMBOL (IC_RESULT (ic))->usl.spillLoc = NULL;
2543 /* if straight assignment then carry remat flag if
2544 this is the only definition */
2545 if (ic->op == '=' &&
2546 !POINTER_SET (ic) &&
2547 IS_SYMOP (IC_RIGHT (ic)) &&
2548 OP_SYMBOL (IC_RIGHT (ic))->remat &&
2549 !IS_CAST_ICODE(OP_SYMBOL (IC_RIGHT (ic))->rematiCode) &&
2550 bitVectnBitsOn (OP_SYMBOL (IC_RESULT (ic))->defs) <= 1)
2553 OP_SYMBOL (IC_RESULT (ic))->remat =
2554 OP_SYMBOL (IC_RIGHT (ic))->remat;
2555 OP_SYMBOL (IC_RESULT (ic))->rematiCode =
2556 OP_SYMBOL (IC_RIGHT (ic))->rematiCode;
2559 /* if cast to a generic pointer & the pointer being
2560 cast is remat, then we can remat this cast as well */
2561 if (ic->op == CAST &&
2562 IS_SYMOP(IC_RIGHT(ic)) &&
2563 OP_SYMBOL(IC_RIGHT(ic))->remat ) {
2564 sym_link *to_type = operandType(IC_LEFT(ic));
2565 sym_link *from_type = operandType(IC_RIGHT(ic));
2566 if (IS_GENPTR(to_type) && IS_PTR(from_type)) {
2567 OP_SYMBOL (IC_RESULT (ic))->remat = 1;
2568 OP_SYMBOL (IC_RESULT (ic))->rematiCode = ic;
2569 OP_SYMBOL (IC_RESULT (ic))->usl.spillLoc = NULL;
2573 /* if this is a +/- operation with a rematerizable
2574 then mark this as rematerializable as well */
2575 if ((ic->op == '+' || ic->op == '-') &&
2576 (IS_SYMOP (IC_LEFT (ic)) &&
2577 IS_ITEMP (IC_RESULT (ic)) &&
2578 IS_OP_LITERAL (IC_RIGHT (ic))) &&
2579 OP_SYMBOL (IC_LEFT (ic))->remat &&
2580 (!IS_SYMOP (IC_RIGHT (ic)) || !IS_CAST_ICODE(OP_SYMBOL (IC_RIGHT (ic))->rematiCode)) &&
2581 bitVectnBitsOn (OP_DEFS (IC_RESULT (ic))) == 1)
2583 OP_SYMBOL (IC_RESULT (ic))->remat = 1;
2584 OP_SYMBOL (IC_RESULT (ic))->rematiCode = ic;
2585 OP_SYMBOL (IC_RESULT (ic))->usl.spillLoc = NULL;
2588 /* mark the pointer usages */
2589 if (POINTER_SET (ic))
2590 OP_SYMBOL (IC_RESULT (ic))->uptr = 1;
2592 if (POINTER_GET (ic))
2593 OP_SYMBOL (IC_LEFT (ic))->uptr = 1;
2597 /* if we are using a symbol on the stack
2598 then we should say mcs51_ptrRegReq */
2599 if (ic->op == IFX && IS_SYMOP (IC_COND (ic)))
2600 mcs51_ptrRegReq += ((OP_SYMBOL (IC_COND (ic))->onStack ||
2601 OP_SYMBOL (IC_COND (ic))->iaccess) ? 1 : 0);
2602 else if (ic->op == JUMPTABLE && IS_SYMOP (IC_JTCOND (ic)))
2603 mcs51_ptrRegReq += ((OP_SYMBOL (IC_JTCOND (ic))->onStack ||
2604 OP_SYMBOL (IC_JTCOND (ic))->iaccess) ? 1 : 0);
2607 if (IS_SYMOP (IC_LEFT (ic)))
2608 mcs51_ptrRegReq += ((OP_SYMBOL (IC_LEFT (ic))->onStack ||
2609 OP_SYMBOL (IC_LEFT (ic))->iaccess) ? 1 : 0);
2610 if (IS_SYMOP (IC_RIGHT (ic)))
2611 mcs51_ptrRegReq += ((OP_SYMBOL (IC_RIGHT (ic))->onStack ||
2612 OP_SYMBOL (IC_RIGHT (ic))->iaccess) ? 1 : 0);
2613 if (IS_SYMOP (IC_RESULT (ic)))
2614 mcs51_ptrRegReq += ((OP_SYMBOL (IC_RESULT (ic))->onStack ||
2615 OP_SYMBOL (IC_RESULT (ic))->iaccess) ? 1 : 0);
2619 /* if the condition of an if instruction
2620 is defined in the previous instruction and
2621 this is the only usage then
2622 mark the itemp as a conditional */
2623 if ((IS_CONDITIONAL (ic) ||
2624 (IS_BITWISE_OP(ic) && isBitwiseOptimizable (ic))) &&
2625 ic->next && ic->next->op == IFX &&
2626 bitVectnBitsOn (OP_USES(IC_RESULT(ic)))==1 &&
2627 isOperandEqual (IC_RESULT (ic), IC_COND (ic->next)) &&
2628 OP_SYMBOL (IC_RESULT (ic))->liveTo <= ic->next->seq)
2630 OP_SYMBOL (IC_RESULT (ic))->regType = REG_CND;
2634 /* reduce for support function calls */
2635 if (ic->supportRtn || ic->op == '+' || ic->op == '-')
2636 packRegsForSupport (ic, ebp);
2638 /* some cases the redundant moves can
2639 can be eliminated for return statements */
2640 if ((ic->op == RETURN || (ic->op == SEND && ic->argreg == 1)) &&
2641 !isOperandInFarSpace (IC_LEFT (ic)) &&
2642 options.model == MODEL_SMALL) {
2643 if (0 && options.stackAuto) {
2644 /* we should check here if acc will be clobbered for stack
2645 offset calculations */
2647 packRegsForOneuse (ic, IC_LEFT (ic), ebp);
2651 /* if pointer set & left has a size more than
2652 one and right is not in far space */
2653 if (POINTER_SET (ic) &&
2654 !isOperandInFarSpace (IC_RIGHT (ic)) &&
2655 !OP_SYMBOL (IC_RESULT (ic))->remat &&
2656 !IS_OP_RUONLY (IC_RIGHT (ic)) &&
2657 getSize (aggrToPtr (operandType (IC_RESULT (ic)), FALSE)) > 1)
2659 packRegsForOneuse (ic, IC_RESULT (ic), ebp);
2661 /* if pointer get */
2662 if (POINTER_GET (ic) &&
2663 !isOperandInFarSpace (IC_RESULT (ic)) &&
2664 !OP_SYMBOL (IC_LEFT (ic))->remat &&
2665 !IS_OP_RUONLY (IC_RESULT (ic)) &&
2666 getSize (aggrToPtr (operandType (IC_LEFT (ic)), FALSE)) > 1)
2668 packRegsForOneuse (ic, IC_LEFT (ic), ebp);
2671 /* if this is cast for intergral promotion then
2672 check if only use of the definition of the
2673 operand being casted/ if yes then replace
2674 the result of that arithmetic operation with
2675 this result and get rid of the cast */
2678 sym_link *fromType = operandType (IC_RIGHT (ic));
2679 sym_link *toType = operandType (IC_LEFT (ic));
2681 if (IS_INTEGRAL (fromType) && IS_INTEGRAL (toType) &&
2682 getSize (fromType) != getSize (toType) &&
2683 SPEC_USIGN (fromType) == SPEC_USIGN (toType))
2686 iCode *dic = packRegsForOneuse (ic, IC_RIGHT (ic), ebp);
2689 if (IS_ARITHMETIC_OP (dic))
2691 bitVectUnSetBit(OP_SYMBOL(IC_RESULT(dic))->defs,dic->key);
2692 IC_RESULT (dic) = IC_RESULT (ic);
2693 remiCodeFromeBBlock (ebp, ic);
2694 bitVectUnSetBit(OP_SYMBOL(IC_RESULT(ic))->defs,ic->key);
2695 hTabDeleteItem (&iCodehTab, ic->key, ic, DELETE_ITEM, NULL);
2696 OP_DEFS_SET ((IC_RESULT (dic)), bitVectSetBit (OP_DEFS (IC_RESULT (dic)), dic->key));
2700 OP_SYMBOL (IC_RIGHT (ic))->ruonly = 0;
2706 /* if the type from and type to are the same
2707 then if this is the only use then packit */
2708 if (compareType (operandType (IC_RIGHT (ic)),
2709 operandType (IC_LEFT (ic))) == 1)
2711 iCode *dic = packRegsForOneuse (ic, IC_RIGHT (ic), ebp);
2714 bitVectUnSetBit(OP_SYMBOL(IC_RESULT(dic))->defs,dic->key);
2715 IC_RESULT (dic) = IC_RESULT (ic);
2716 remiCodeFromeBBlock (ebp, ic);
2717 bitVectUnSetBit(OP_SYMBOL(IC_RESULT(ic))->defs,ic->key);
2718 hTabDeleteItem (&iCodehTab, ic->key, ic, DELETE_ITEM, NULL);
2719 OP_DEFS_SET ((IC_RESULT (dic)), bitVectSetBit (OP_DEFS (IC_RESULT (dic)), dic->key));
2727 iTempNN := (some variable in farspace) V1
2732 if (ic->op == IPUSH)
2734 packForPush (ic, ebpp, blockno);
2738 /* pack registers for accumulator use, when the
2739 result of an arithmetic or bit wise operation
2740 has only one use, that use is immediately following
2741 the defintion and the using iCode has only one
2742 operand or has two operands but one is literal &
2743 the result of that operation is not on stack then
2744 we can leave the result of this operation in acc:b
2746 if ((IS_ARITHMETIC_OP (ic)
2747 || IS_CONDITIONAL(ic)
2748 || IS_BITWISE_OP (ic)
2749 || ic->op == LEFT_OP || ic->op == RIGHT_OP || ic->op == CALL
2750 || (ic->op == ADDRESS_OF && isOperandOnStack (IC_LEFT (ic)))
2752 IS_ITEMP (IC_RESULT (ic)) &&
2753 getSize (operandType (IC_RESULT (ic))) <= 2)
2755 packRegsForAccUse (ic);
2759 /*-----------------------------------------------------------------*/
2760 /* assignRegisters - assigns registers to each live range as need */
2761 /*-----------------------------------------------------------------*/
2763 mcs51_assignRegisters (eBBlock ** ebbs, int count)
2768 setToNull ((void *) &_G.funcrUsed);
2769 setToNull ((void *) &_G.totRegAssigned);
2770 mcs51_ptrRegReq = _G.stackExtend = _G.dataExtend = 0;
2773 /* change assignments this will remove some
2774 live ranges reducing some register pressure */
2775 for (i = 0; i < count; i++)
2776 packRegisters (ebbs, i);
2778 if (options.dump_pack)
2779 dumpEbbsToFileExt (DUMP_PACK, ebbs, count);
2781 /* first determine for each live range the number of
2782 registers & the type of registers required for each */
2785 /* and serially allocate registers */
2786 serialRegAssign (ebbs, count);
2791 /* if stack was extended then tell the user */
2794 /* werror(W_TOOMANY_SPILS,"stack", */
2795 /* _G.stackExtend,currFunc->name,""); */
2801 /* werror(W_TOOMANY_SPILS,"data space", */
2802 /* _G.dataExtend,currFunc->name,""); */
2806 /* after that create the register mask
2807 for each of the instruction */
2808 createRegMask (ebbs, count);
2810 /* redo that offsets for stacked automatic variables */
2811 redoStackOffsets ();
2813 if (options.dump_rassgn)
2815 dumpEbbsToFileExt (DUMP_RASSGN, ebbs, count);
2816 dumpLiveRanges (DUMP_LRANGE, liveRanges);
2819 /* do the overlaysegment stuff SDCCmem.c */
2820 doOverlays (ebbs, count);
2822 /* now get back the chain */
2823 ic = iCodeLabelOptimize (iCodeFromeBBlock (ebbs, count));
2827 /* free up any _G.stackSpil locations allocated */
2828 applyToSet (_G.stackSpil, deallocStackSpil);
2830 setToNull ((void **) &_G.stackSpil);
2831 setToNull ((void **) &_G.spiltSet);
2832 /* mark all registers as free */