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);
574 /* mark it has spilt & put it in the spilt set */
575 sym->isspilt = sym->spillA = 1;
576 _G.spiltSet = bitVectSetBit (_G.spiltSet, sym->key);
578 bitVectUnSetBit (_G.regAssigned, sym->key);
579 bitVectUnSetBit (_G.totRegAssigned, sym->key);
581 for (i = 0; i < sym->nRegs; i++)
585 freeReg (sym->regs[i]);
589 /* if spilt on stack then free up r0 & r1
590 if they could have been assigned to some
592 if (!mcs51_ptrRegReq && isSpiltOnStack (sym))
595 spillLRWithPtrReg (sym);
598 if (sym->usl.spillLoc && !sym->remat)
599 sym->usl.spillLoc->allocreq++;
603 /*-----------------------------------------------------------------*/
604 /* selectSpil - select a iTemp to spil : rather a simple procedure */
605 /*-----------------------------------------------------------------*/
607 selectSpil (iCode * ic, eBBlock * ebp, symbol * forSym)
609 bitVect *lrcs = NULL;
613 /* get the spillable live ranges */
614 lrcs = computeSpillable (ic);
616 /* get all live ranges that are rematerizable */
617 if ((selectS = liveRangesWith (lrcs, rematable, ebp, ic)))
620 /* return the least used of these */
621 return leastUsedLR (selectS);
624 /* get live ranges with spillLocations in direct space */
625 if ((selectS = liveRangesWith (lrcs, directSpilLoc, ebp, ic)))
627 sym = leastUsedLR (selectS);
628 strcpy (sym->rname, (sym->usl.spillLoc->rname[0] ?
629 sym->usl.spillLoc->rname :
630 sym->usl.spillLoc->name));
632 /* mark it as allocation required */
633 sym->usl.spillLoc->allocreq++;
637 /* if the symbol is local to the block then */
638 if (forSym->liveTo < ebp->lSeq)
641 /* check if there are any live ranges allocated
642 to registers that are not used in this block */
643 if (!_G.blockSpil && (selectS = liveRangesWith (lrcs, notUsedInBlock, ebp, ic)))
645 sym = leastUsedLR (selectS);
646 /* if this is not rematerializable */
655 /* check if there are any live ranges that not
656 used in the remainder of the block */
657 if (!_G.blockSpil && (selectS = liveRangesWith (lrcs, notUsedInRemaining, ebp, ic)))
659 sym = leastUsedLR (selectS);
672 /* find live ranges with spillocation && not used as pointers */
673 if ((selectS = liveRangesWith (lrcs, hasSpilLocnoUptr, ebp, ic)))
676 sym = leastUsedLR (selectS);
677 /* mark this as allocation required */
678 sym->usl.spillLoc->allocreq++;
682 /* find live ranges with spillocation */
683 if ((selectS = liveRangesWith (lrcs, hasSpilLoc, ebp, ic)))
686 sym = leastUsedLR (selectS);
687 sym->usl.spillLoc->allocreq++;
691 /* couldn't find then we need to create a spil
692 location on the stack , for which one? the least
694 if ((selectS = liveRangesWith (lrcs, noSpilLoc, ebp, ic)))
697 /* return a created spil location */
698 sym = createStackSpil (leastUsedLR (selectS));
699 sym->usl.spillLoc->allocreq++;
703 /* this is an extreme situation we will spill
704 this one : happens very rarely but it does happen */
710 /*-----------------------------------------------------------------*/
711 /* spilSomething - spil some variable & mark registers as free */
712 /*-----------------------------------------------------------------*/
714 spilSomething (iCode * ic, eBBlock * ebp, symbol * forSym)
719 /* get something we can spil */
720 ssym = selectSpil (ic, ebp, forSym);
722 /* mark it as spilt */
723 ssym->isspilt = ssym->spillA = 1;
724 _G.spiltSet = bitVectSetBit (_G.spiltSet, ssym->key);
726 /* mark it as not register assigned &
727 take it away from the set */
728 bitVectUnSetBit (_G.regAssigned, ssym->key);
729 bitVectUnSetBit (_G.totRegAssigned, ssym->key);
731 /* mark the registers as free */
732 for (i = 0; i < ssym->nRegs; i++)
734 freeReg (ssym->regs[i]);
736 /* if spilt on stack then free up r0 & r1
737 if they could have been assigned to as gprs */
738 if (!mcs51_ptrRegReq && isSpiltOnStack (ssym))
741 spillLRWithPtrReg (ssym);
744 /* if this was a block level spil then insert push & pop
745 at the start & end of block respectively */
748 iCode *nic = newiCode (IPUSH, operandFromSymbol (ssym), NULL);
749 /* add push to the start of the block */
750 addiCodeToeBBlock (ebp, nic, (ebp->sch->op == LABEL ?
751 ebp->sch->next : ebp->sch));
752 nic = newiCode (IPOP, operandFromSymbol (ssym), NULL);
753 /* add pop to the end of the block */
754 addiCodeToeBBlock (ebp, nic, NULL);
757 /* if spilt because not used in the remainder of the
758 block then add a push before this instruction and
759 a pop at the end of the block */
760 if (ssym->remainSpil)
763 iCode *nic = newiCode (IPUSH, operandFromSymbol (ssym), NULL);
764 /* add push just before this instruction */
765 addiCodeToeBBlock (ebp, nic, ic);
767 nic = newiCode (IPOP, operandFromSymbol (ssym), NULL);
768 /* add pop to the end of the block */
769 addiCodeToeBBlock (ebp, nic, NULL);
778 /*-----------------------------------------------------------------*/
779 /* getRegPtr - will try for PTR if not a GPR type if not spil */
780 /*-----------------------------------------------------------------*/
782 getRegPtr (iCode * ic, eBBlock * ebp, symbol * sym)
787 /* try for a ptr type */
788 if ((reg = allocReg (REG_PTR)))
791 /* try for gpr type */
792 if ((reg = allocReg (REG_GPR)))
795 /* we have to spil */
796 if (!spilSomething (ic, ebp, sym))
799 /* this looks like an infinite loop but
800 in really selectSpil will abort */
804 /*-----------------------------------------------------------------*/
805 /* getRegGpr - will try for GPR if not spil */
806 /*-----------------------------------------------------------------*/
808 getRegGpr (iCode * ic, eBBlock * ebp, symbol * sym)
813 /* try for gpr type */
814 if ((reg = allocReg (REG_GPR)))
817 if (!mcs51_ptrRegReq)
818 if ((reg = allocReg (REG_PTR)))
821 /* we have to spil */
822 if (!spilSomething (ic, ebp, sym))
825 /* this looks like an infinite loop but
826 in really selectSpil will abort */
830 /*-----------------------------------------------------------------*/
831 /* getRegPtrNoSpil - get it cannot split */
832 /*-----------------------------------------------------------------*/
833 static regs *getRegPtrNoSpil()
837 /* try for a ptr type */
838 if ((reg = allocReg (REG_PTR)))
841 /* try for gpr type */
842 if ((reg = allocReg (REG_GPR)))
847 /* just to make the compiler happy */
851 /*-----------------------------------------------------------------*/
852 /* getRegGprNoSpil - get it cannot split */
853 /*-----------------------------------------------------------------*/
854 static regs *getRegGprNoSpil()
858 if ((reg = allocReg (REG_GPR)))
861 if (!mcs51_ptrRegReq)
862 if ((reg = allocReg (REG_PTR)))
867 /* just to make the compiler happy */
871 /*-----------------------------------------------------------------*/
872 /* symHasReg - symbol has a given register */
873 /*-----------------------------------------------------------------*/
875 symHasReg (symbol * sym, regs * reg)
879 for (i = 0; i < sym->nRegs; i++)
880 if (sym->regs[i] == reg)
886 /*-----------------------------------------------------------------*/
887 /* deassignLRs - check the live to and if they have registers & are */
888 /* not spilt then free up the registers */
889 /*-----------------------------------------------------------------*/
891 deassignLRs (iCode * ic, eBBlock * ebp)
897 for (sym = hTabFirstItem (liveRanges, &k); sym;
898 sym = hTabNextItem (liveRanges, &k))
902 /* if it does not end here */
903 if (sym->liveTo > ic->seq)
906 /* if it was spilt on stack then we can
907 mark the stack spil location as free */
912 sym->usl.spillLoc->isFree = 1;
918 if (!bitVectBitValue (_G.regAssigned, sym->key))
921 /* special case check if this is an IFX &
922 the privious one was a pop and the
923 previous one was not spilt then keep track
925 if (ic->op == IFX && ic->prev &&
926 ic->prev->op == IPOP &&
927 !ic->prev->parmPush &&
928 !OP_SYMBOL (IC_LEFT (ic->prev))->isspilt)
929 psym = OP_SYMBOL (IC_LEFT (ic->prev));
935 bitVectUnSetBit (_G.regAssigned, sym->key);
937 /* if the result of this one needs registers
938 and does not have it then assign it right
940 if (IC_RESULT (ic) &&
941 !(SKIP_IC2 (ic) || /* not a special icode */
942 ic->op == JUMPTABLE ||
948 (result = OP_SYMBOL (IC_RESULT (ic))) && /* has a result */
949 result->liveTo > ic->seq && /* and will live beyond this */
950 result->liveTo <= ebp->lSeq && /* does not go beyond this block */
951 result->regType == sym->regType && /* same register types */
952 result->nRegs && /* which needs registers */
953 !result->isspilt && /* and does not already have them */
955 !bitVectBitValue (_G.regAssigned, result->key) &&
956 /* the number of free regs + number of regs in this LR
957 can accomodate the what result Needs */
958 ((nfreeRegsType (result->regType) +
959 sym->nRegs) >= result->nRegs)
963 for (i = 0; i < result->nRegs; i++)
965 result->regs[i] = sym->regs[i];
967 result->regs[i] = getRegGpr (ic, ebp, result);
969 _G.regAssigned = bitVectSetBit (_G.regAssigned, result->key);
970 _G.totRegAssigned = bitVectSetBit (_G.totRegAssigned, result->key);
974 /* free the remaining */
975 for (; i < sym->nRegs; i++)
979 if (!symHasReg (psym, sym->regs[i]))
980 freeReg (sym->regs[i]);
983 freeReg (sym->regs[i]);
990 /*-----------------------------------------------------------------*/
991 /* reassignLR - reassign this to registers */
992 /*-----------------------------------------------------------------*/
994 reassignLR (operand * op)
996 symbol *sym = OP_SYMBOL (op);
999 /* not spilt any more */
1000 sym->isspilt = sym->spillA = sym->blockSpil = sym->remainSpil = 0;
1001 bitVectUnSetBit (_G.spiltSet, sym->key);
1003 _G.regAssigned = bitVectSetBit (_G.regAssigned, sym->key);
1004 _G.totRegAssigned = bitVectSetBit (_G.totRegAssigned, sym->key);
1008 for (i = 0; i < sym->nRegs; i++)
1009 sym->regs[i]->isFree = 0;
1012 /*-----------------------------------------------------------------*/
1013 /* willCauseSpill - determines if allocating will cause a spill */
1014 /*-----------------------------------------------------------------*/
1016 willCauseSpill (int nr, int rt)
1018 /* first check if there are any avlb registers
1019 of te type required */
1022 /* special case for pointer type
1023 if pointer type not avlb then
1024 check for type gpr */
1025 if (nFreeRegs (rt) >= nr)
1027 if (nFreeRegs (REG_GPR) >= nr)
1032 if (mcs51_ptrRegReq)
1034 if (nFreeRegs (rt) >= nr)
1039 if (nFreeRegs (REG_PTR) +
1040 nFreeRegs (REG_GPR) >= nr)
1045 /* it will cause a spil */
1049 /*-----------------------------------------------------------------*/
1050 /* positionRegs - the allocator can allocate same registers to res- */
1051 /* ult and operand, if this happens make sure they are in the same */
1052 /* position as the operand otherwise chaos results */
1053 /*-----------------------------------------------------------------*/
1055 positionRegs (symbol * result, symbol * opsym)
1057 int count = min (result->nRegs, opsym->nRegs);
1058 int i, j = 0, shared = 0;
1061 /* if the result has been spilt then cannot share */
1066 /* first make sure that they actually share */
1067 for (i = 0; i < count; i++)
1069 for (j = 0; j < count; j++)
1071 if (result->regs[i] == opsym->regs[j] && i != j)
1081 regs *tmp = result->regs[i];
1082 result->regs[i] = result->regs[j];
1083 result->regs[j] = tmp;
1090 /*-----------------------------------------------------------------*/
1091 /* serialRegAssign - serially allocate registers to the variables */
1092 /*-----------------------------------------------------------------*/
1094 serialRegAssign (eBBlock ** ebbs, int count)
1098 /* for all blocks */
1099 for (i = 0; i < count; i++) {
1103 if (ebbs[i]->noPath &&
1104 (ebbs[i]->entryLabel != entryLabel &&
1105 ebbs[i]->entryLabel != returnLabel))
1108 /* of all instructions do */
1109 for (ic = ebbs[i]->sch; ic; ic = ic->next) {
1111 /* if this is an ipop that means some live
1112 range will have to be assigned again */
1114 reassignLR (IC_LEFT (ic));
1116 /* if result is present && is a true symbol */
1117 if (IC_RESULT (ic) && ic->op != IFX &&
1118 IS_TRUE_SYMOP (IC_RESULT (ic)))
1119 OP_SYMBOL (IC_RESULT (ic))->allocreq++;
1121 /* take away registers from live
1122 ranges that end at this instruction */
1123 deassignLRs (ic, ebbs[i]);
1125 /* some don't need registers */
1126 if (SKIP_IC2 (ic) ||
1127 ic->op == JUMPTABLE ||
1131 (IC_RESULT (ic) && POINTER_SET (ic)))
1134 /* now we need to allocate registers
1135 only for the result */
1136 if (IC_RESULT (ic)) {
1137 symbol *sym = OP_SYMBOL (IC_RESULT (ic));
1143 /* if it does not need or is spilt
1144 or is already assigned to registers
1145 or will not live beyond this instructions */
1148 bitVectBitValue (_G.regAssigned, sym->key) ||
1149 sym->liveTo <= ic->seq)
1152 /* if some liverange has been spilt at the block level
1153 and this one live beyond this block then spil this
1155 if (_G.blockSpil && sym->liveTo > ebbs[i]->lSeq) {
1159 /* if trying to allocate this will cause
1160 a spill and there is nothing to spill
1161 or this one is rematerializable then
1163 willCS = willCauseSpill (sym->nRegs, sym->regType);
1164 spillable = computeSpillable (ic);
1165 if (sym->remat || (willCS && bitVectIsZero (spillable))) {
1170 /* if it has a spillocation & is used less than
1171 all other live ranges then spill this */
1173 if (sym->usl.spillLoc) {
1174 symbol *leastUsed = leastUsedLR (liveRangesWith (spillable,
1175 allLRs, ebbs[i], ic));
1176 if (leastUsed && leastUsed->used > sym->used) {
1181 /* if none of the liveRanges have a spillLocation then better
1182 to spill this one than anything else already assigned to registers */
1183 if (liveRangesWith(spillable,noSpilLoc,ebbs[i],ic)) {
1184 /* if this is local to this block then we might find a block spil */
1185 if (!(sym->liveFrom >= ebbs[i]->fSeq && sym->liveTo <= ebbs[i]->lSeq)) {
1192 /* if we need ptr regs for the right side
1194 if (POINTER_GET (ic) && IS_SYMOP (IC_LEFT (ic))
1195 && getSize (OP_SYMBOL (IC_LEFT (ic))->type) <= (unsigned int) PTRSIZE) {
1199 /* else we assign registers to it */
1200 _G.regAssigned = bitVectSetBit (_G.regAssigned, sym->key);
1201 _G.totRegAssigned = bitVectSetBit (_G.totRegAssigned, sym->key);
1203 for (j = 0; j < sym->nRegs; j++) {
1204 if (sym->regType == REG_PTR)
1205 sym->regs[j] = getRegPtr (ic, ebbs[i], sym);
1207 sym->regs[j] = getRegGpr (ic, ebbs[i], sym);
1209 /* if the allocation failed which means
1210 this was spilt then break */
1211 if (!sym->regs[j]) {
1216 /* if it shares registers with operands make sure
1217 that they are in the same position */
1218 if (IC_LEFT (ic) && IS_SYMOP (IC_LEFT (ic)) &&
1219 OP_SYMBOL (IC_LEFT (ic))->nRegs && ic->op != '=') {
1220 positionRegs (OP_SYMBOL (IC_RESULT (ic)),
1221 OP_SYMBOL (IC_LEFT (ic)));
1223 /* do the same for the right operand */
1224 if (IC_RIGHT (ic) && IS_SYMOP (IC_RIGHT (ic)) &&
1225 OP_SYMBOL (IC_RIGHT (ic))->nRegs) {
1226 positionRegs (OP_SYMBOL (IC_RESULT (ic)),
1227 OP_SYMBOL (IC_RIGHT (ic)));
1240 /*-----------------------------------------------------------------*/
1241 /* fillGaps - Try to fill in the Gaps left by Pass1 */
1242 /*-----------------------------------------------------------------*/
1243 static void fillGaps()
1248 if (getenv("DISABLE_FILL_GAPS")) return;
1250 /* look for livernages that was spilt by the allocator */
1251 for (sym = hTabFirstItem(liveRanges,&key) ; sym ;
1252 sym = hTabNextItem(liveRanges,&key)) {
1257 if (!sym->spillA || !sym->clashes || sym->remat) continue ;
1259 /* find the liveRanges this one clashes with, that are
1260 still assigned to registers & mark the registers as used*/
1261 for ( i = 0 ; i < sym->clashes->size ; i ++) {
1265 if (bitVectBitValue(sym->clashes,i) == 0 || /* those that clash with this */
1266 bitVectBitValue(_G.totRegAssigned,i) == 0) /* and are still assigned to registers */
1269 clr = hTabItemWithKey(liveRanges,i);
1272 /* mark these registers as used */
1273 for (k = 0 ; k < clr->nRegs ; k++ )
1274 useReg(clr->regs[k]);
1277 if (willCauseSpill(sym->nRegs,sym->regType)) {
1278 /* NOPE :( clear all registers & and continue */
1283 /* THERE IS HOPE !!!! */
1284 for (i=0; i < sym->nRegs ; i++ ) {
1285 if (sym->regType == REG_PTR)
1286 sym->regs[i] = getRegPtrNoSpil ();
1288 sym->regs[i] = getRegGprNoSpil ();
1291 /* for all its definitions check if the registers
1292 allocated needs positioning NOTE: we can position
1293 only ONCE if more than One positioning required
1296 for (i = 0 ; i < sym->defs->size ; i++ ) {
1297 if (bitVectBitValue(sym->defs,i)) {
1299 if (!(ic = hTabItemWithKey(iCodehTab,i))) continue ;
1300 if (SKIP_IC(ic)) continue;
1301 assert(isSymbolEqual(sym,OP_SYMBOL(IC_RESULT(ic)))); /* just making sure */
1302 /* if left is assigned to registers */
1303 if (IS_SYMOP(IC_LEFT(ic)) &&
1304 bitVectBitValue(_G.totRegAssigned,OP_SYMBOL(IC_LEFT(ic))->key)) {
1305 pdone += positionRegs(sym,OP_SYMBOL(IC_LEFT(ic)));
1307 if (IS_SYMOP(IC_RIGHT(ic)) &&
1308 bitVectBitValue(_G.totRegAssigned,OP_SYMBOL(IC_RIGHT(ic))->key)) {
1309 pdone += positionRegs(sym,OP_SYMBOL(IC_RIGHT(ic)));
1311 if (pdone > 1) break;
1314 for (i = 0 ; i < sym->uses->size ; i++ ) {
1315 if (bitVectBitValue(sym->uses,i)) {
1317 if (!(ic = hTabItemWithKey(iCodehTab,i))) continue ;
1318 if (SKIP_IC(ic)) continue;
1319 if (!IS_ASSIGN_ICODE(ic)) continue ;
1321 /* if result is assigned to registers */
1322 if (IS_SYMOP(IC_RESULT(ic)) &&
1323 bitVectBitValue(_G.totRegAssigned,OP_SYMBOL(IC_RESULT(ic))->key)) {
1324 pdone += positionRegs(sym,OP_SYMBOL(IC_RESULT(ic)));
1326 if (pdone > 1) break;
1329 /* had to position more than once GIVE UP */
1331 /* UNDO all the changes we made to try this */
1333 for (i=0; i < sym->nRegs ; i++ ) {
1334 sym->regs[i] = NULL;
1337 D(printf ("Fill Gap gave up due to positioning for %s in function %s\n",sym->name, currFunc ? currFunc->name : "UNKNOWN"));
1340 D(printf ("FILLED GAP for %s in function %s\n",sym->name, currFunc ? currFunc->name : "UNKNOWN"));
1341 _G.totRegAssigned = bitVectSetBit(_G.totRegAssigned,sym->key);
1342 sym->isspilt = sym->spillA = 0 ;
1343 sym->usl.spillLoc->allocreq--;
1348 /*-----------------------------------------------------------------*/
1349 /* rUmaskForOp :- returns register mask for an operand */
1350 /*-----------------------------------------------------------------*/
1352 mcs51_rUmaskForOp (operand * op)
1358 /* only temporaries are assigned registers */
1362 sym = OP_SYMBOL (op);
1364 /* if spilt or no registers assigned to it
1366 if (sym->isspilt || !sym->nRegs)
1369 rumask = newBitVect (mcs51_nRegs);
1371 for (j = 0; j < sym->nRegs; j++)
1373 rumask = bitVectSetBit (rumask,
1374 sym->regs[j]->rIdx);
1380 /*-----------------------------------------------------------------*/
1381 /* regsUsedIniCode :- returns bit vector of registers used in iCode */
1382 /*-----------------------------------------------------------------*/
1384 regsUsedIniCode (iCode * ic)
1386 bitVect *rmask = newBitVect (mcs51_nRegs);
1388 /* do the special cases first */
1391 rmask = bitVectUnion (rmask,
1392 mcs51_rUmaskForOp (IC_COND (ic)));
1396 /* for the jumptable */
1397 if (ic->op == JUMPTABLE)
1399 rmask = bitVectUnion (rmask,
1400 mcs51_rUmaskForOp (IC_JTCOND (ic)));
1405 /* of all other cases */
1407 rmask = bitVectUnion (rmask,
1408 mcs51_rUmaskForOp (IC_LEFT (ic)));
1412 rmask = bitVectUnion (rmask,
1413 mcs51_rUmaskForOp (IC_RIGHT (ic)));
1416 rmask = bitVectUnion (rmask,
1417 mcs51_rUmaskForOp (IC_RESULT (ic)));
1423 /*-----------------------------------------------------------------*/
1424 /* createRegMask - for each instruction will determine the regsUsed */
1425 /*-----------------------------------------------------------------*/
1427 createRegMask (eBBlock ** ebbs, int count)
1431 /* for all blocks */
1432 for (i = 0; i < count; i++)
1436 if (ebbs[i]->noPath &&
1437 (ebbs[i]->entryLabel != entryLabel &&
1438 ebbs[i]->entryLabel != returnLabel))
1441 /* for all instructions */
1442 for (ic = ebbs[i]->sch; ic; ic = ic->next)
1447 if (SKIP_IC2 (ic) || !ic->rlive)
1450 /* first mark the registers used in this
1452 ic->rUsed = regsUsedIniCode (ic);
1453 _G.funcrUsed = bitVectUnion (_G.funcrUsed, ic->rUsed);
1455 /* now create the register mask for those
1456 registers that are in use : this is a
1457 super set of ic->rUsed */
1458 ic->rMask = newBitVect (mcs51_nRegs + 1);
1460 /* for all live Ranges alive at this point */
1461 for (j = 1; j < ic->rlive->size; j++)
1466 /* if not alive then continue */
1467 if (!bitVectBitValue (ic->rlive, j))
1470 /* find the live range we are interested in */
1471 if (!(sym = hTabItemWithKey (liveRanges, j)))
1473 werror (E_INTERNAL_ERROR, __FILE__, __LINE__,
1474 "createRegMask cannot find live range");
1475 fprintf(stderr, "\tmissing live range: key=%d\n", j);
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);
1566 /* if this symbol has only one usage and that is an assignment
1567 to a ruonly, we don't need registers */
1568 // if this symbol has only one def
1569 if (bitVectnBitsOn (sym->defs)==1) {
1570 printf ("sym: %s has only one usage", sym->name);
1572 if ((ic = hTabItemWithKey (iCodehTab, bitVectFirstBit (sym->defs)))) {
1574 printf (" for a call ");
1575 // if this is only assigned to a ruonly
1576 if ((ic = hTabItemWithKey (iCodehTab, bitVectFirstBit (sym->defs)))) {
1578 if (OP_SYMBOL(IC_RESULT(ic))->ruonly) {
1579 printf("regTypeNum: %s assigned to %s\n", \
1580 sym->name, OP_SYMBOL(IC_RESULT(ic))->name);
1589 /* if the symbol has only one definition &
1590 that definition is a get_pointer */
1591 if (bitVectnBitsOn (sym->defs) == 1 &&
1592 (ic = hTabItemWithKey (iCodehTab,
1593 bitVectFirstBit (sym->defs))) &&
1596 !IS_BITVAR (sym->etype))
1600 /* and that pointer is remat in data space */
1601 if (IS_SYMOP (IC_LEFT (ic)) &&
1602 OP_SYMBOL (IC_LEFT (ic))->remat &&
1603 !IS_CAST_ICODE(OP_SYMBOL (IC_LEFT (ic))->rematiCode) &&
1604 DCL_TYPE (aggrToPtr (operandType(IC_LEFT(ic)), FALSE)) == POINTER)
1606 /* create a psuedo symbol & force a spil */
1607 symbol *psym = newSymbol (rematStr (OP_SYMBOL (IC_LEFT (ic))), 1);
1608 psym->type = sym->type;
1609 psym->etype = sym->etype;
1610 strcpy (psym->rname, psym->name);
1612 sym->usl.spillLoc = psym;
1613 #if 0 // an alternative fix for bug #480076
1614 /* now this is a useless assignment to itself */
1615 remiCodeFromeBBlock (ebbs, ic);
1617 /* now this really is an assignment to itself, make it so;
1618 it will be optimized out later */
1620 ReplaceOpWithCheaperOp(&IC_RIGHT(ic), IC_RESULT(ic));
1626 /* if in data space or idata space then try to
1627 allocate pointer register */
1631 /* if not then we require registers */
1632 sym->nRegs = ((IS_AGGREGATE (sym->type) || sym->isptr) ?
1633 getSize (sym->type = aggrToPtr (sym->type, FALSE)) :
1634 getSize (sym->type));
1638 fprintf (stderr, "allocated more than 4 or 0 registers for type ");
1639 printTypeChain (sym->type, stderr);
1640 fprintf (stderr, "\n");
1643 /* determine the type of register required */
1644 if (sym->nRegs == 1 &&
1645 IS_PTR (sym->type) &&
1647 sym->regType = REG_PTR;
1649 sym->regType = REG_GPR;
1653 /* for the first run we don't provide */
1654 /* registers for true symbols we will */
1655 /* see how things go */
1661 /*-----------------------------------------------------------------*/
1662 /* freeAllRegs - mark all registers as free */
1663 /*-----------------------------------------------------------------*/
1669 for (i = 0; i < mcs51_nRegs; i++)
1670 regs8051[i].isFree = 1;
1673 /*-----------------------------------------------------------------*/
1674 /* deallocStackSpil - this will set the stack pointer back */
1675 /*-----------------------------------------------------------------*/
1677 DEFSETFUNC (deallocStackSpil)
1685 /*-----------------------------------------------------------------*/
1686 /* farSpacePackable - returns the packable icode for far variables */
1687 /*-----------------------------------------------------------------*/
1689 farSpacePackable (iCode * ic)
1693 /* go thru till we find a definition for the
1694 symbol on the right */
1695 for (dic = ic->prev; dic; dic = dic->prev)
1697 /* if the definition is a call then no */
1698 if ((dic->op == CALL || dic->op == PCALL) &&
1699 IC_RESULT (dic)->key == IC_RIGHT (ic)->key)
1704 /* if shift by unknown amount then not */
1705 if ((dic->op == LEFT_OP || dic->op == RIGHT_OP) &&
1706 IC_RESULT (dic)->key == IC_RIGHT (ic)->key)
1709 /* if pointer get and size > 1 */
1710 if (POINTER_GET (dic) &&
1711 getSize (aggrToPtr (operandType (IC_LEFT (dic)), FALSE)) > 1)
1714 if (POINTER_SET (dic) &&
1715 getSize (aggrToPtr (operandType (IC_RESULT (dic)), FALSE)) > 1)
1718 /* if any three is a true symbol in far space */
1719 if (IC_RESULT (dic) &&
1720 IS_TRUE_SYMOP (IC_RESULT (dic)) &&
1721 isOperandInFarSpace (IC_RESULT (dic)))
1724 if (IC_RIGHT (dic) &&
1725 IS_TRUE_SYMOP (IC_RIGHT (dic)) &&
1726 isOperandInFarSpace (IC_RIGHT (dic)) &&
1727 !isOperandEqual (IC_RIGHT (dic), IC_RESULT (ic)))
1730 if (IC_LEFT (dic) &&
1731 IS_TRUE_SYMOP (IC_LEFT (dic)) &&
1732 isOperandInFarSpace (IC_LEFT (dic)) &&
1733 !isOperandEqual (IC_LEFT (dic), IC_RESULT (ic)))
1736 if (isOperandEqual (IC_RIGHT (ic), IC_RESULT (dic)))
1738 if ((dic->op == LEFT_OP ||
1739 dic->op == RIGHT_OP ||
1741 IS_OP_LITERAL (IC_RIGHT (dic)))
1751 /*-----------------------------------------------------------------*/
1752 /* packRegsForAssign - register reduction for assignment */
1753 /*-----------------------------------------------------------------*/
1755 packRegsForAssign (iCode * ic, eBBlock * ebp)
1759 if (!IS_ITEMP (IC_RIGHT (ic)) ||
1760 OP_SYMBOL (IC_RIGHT (ic))->isind ||
1761 OP_LIVETO (IC_RIGHT (ic)) > ic->seq)
1767 /* if the true symbol is defined in far space or on stack
1768 then we should not since this will increase register pressure */
1769 if (isOperandInFarSpace(IC_RESULT(ic)) && !farSpacePackable(ic)) {
1773 /* find the definition of iTempNN scanning backwards if we find a
1774 a use of the true symbol in before we find the definition then
1776 for (dic = ic->prev; dic; dic = dic->prev)
1778 /* if there is a function call then don't pack it */
1779 if ((dic->op == CALL || dic->op == PCALL))
1788 if (IS_TRUE_SYMOP (IC_RESULT (dic)) &&
1789 IS_OP_VOLATILE (IC_RESULT (dic)))
1795 if (IS_SYMOP (IC_RESULT (dic)) &&
1796 IC_RESULT (dic)->key == IC_RIGHT (ic)->key)
1798 if (POINTER_SET (dic))
1804 if (IS_SYMOP (IC_RIGHT (dic)) &&
1805 (IC_RIGHT (dic)->key == IC_RESULT (ic)->key ||
1806 IC_RIGHT (dic)->key == IC_RIGHT (ic)->key))
1812 if (IS_SYMOP (IC_LEFT (dic)) &&
1813 (IC_LEFT (dic)->key == IC_RESULT (ic)->key ||
1814 IC_LEFT (dic)->key == IC_RIGHT (ic)->key))
1820 if (POINTER_SET (dic) &&
1821 IC_RESULT (dic)->key == IC_RESULT (ic)->key)
1829 return 0; /* did not find */
1831 /* if assignment then check that right is not a bit */
1832 if (ASSIGNMENT (dic) && !POINTER_SET (dic))
1834 sym_link *etype = operandType (IC_RIGHT (dic));
1835 if (IS_BITFIELD (etype))
1837 /* if result is a bit too then it's ok */
1838 etype = operandType (IC_RESULT (dic));
1839 if (!IS_BITFIELD (etype))
1843 /* if the result is on stack or iaccess then it must be
1844 the same atleast one of the operands */
1845 if (OP_SYMBOL (IC_RESULT (ic))->onStack ||
1846 OP_SYMBOL (IC_RESULT (ic))->iaccess)
1849 /* the operation has only one symbol
1850 operator then we can pack */
1851 if ((IC_LEFT (dic) && !IS_SYMOP (IC_LEFT (dic))) ||
1852 (IC_RIGHT (dic) && !IS_SYMOP (IC_RIGHT (dic))))
1855 if (!((IC_LEFT (dic) &&
1856 IC_RESULT (ic)->key == IC_LEFT (dic)->key) ||
1858 IC_RESULT (ic)->key == IC_RIGHT (dic)->key)))
1862 /* found the definition */
1863 /* replace the result with the result of */
1864 /* this assignment and remove this assignment */
1865 bitVectUnSetBit(OP_SYMBOL(IC_RESULT(dic))->defs,dic->key);
1866 ReplaceOpWithCheaperOp(&IC_RESULT (dic), IC_RESULT (ic));
1868 if (IS_ITEMP (IC_RESULT (dic)) && OP_SYMBOL (IC_RESULT (dic))->liveFrom > dic->seq)
1870 OP_SYMBOL (IC_RESULT (dic))->liveFrom = dic->seq;
1872 // TODO: and the otherway around?
1874 /* delete from liverange table also
1875 delete from all the points inbetween and the new
1877 for (sic = dic; sic != ic; sic = sic->next)
1879 bitVectUnSetBit (sic->rlive, IC_RESULT (ic)->key);
1880 if (IS_ITEMP (IC_RESULT (dic)))
1881 bitVectSetBit (sic->rlive, IC_RESULT (dic)->key);
1884 remiCodeFromeBBlock (ebp, ic);
1885 bitVectUnSetBit(OP_SYMBOL(IC_RESULT(ic))->defs,ic->key);
1886 hTabDeleteItem (&iCodehTab, ic->key, ic, DELETE_ITEM, NULL);
1887 OP_DEFS(IC_RESULT (dic))=bitVectSetBit (OP_DEFS (IC_RESULT (dic)), dic->key);
1891 /*------------------------------------------------------------------*/
1892 /* findAssignToSym : scanning backwards looks for first assig found */
1893 /*------------------------------------------------------------------*/
1895 findAssignToSym (operand * op, iCode * ic)
1899 /* This routine is used to find sequences like
1901 ...; (intervening ops don't use iTempAA or modify FOO)
1902 blah = blah + iTempAA;
1904 and eliminate the use of iTempAA, freeing up its register for
1909 for (dic = ic->prev; dic; dic = dic->prev)
1912 /* if definition by assignment */
1913 if (dic->op == '=' &&
1914 !POINTER_SET (dic) &&
1915 IC_RESULT (dic)->key == op->key
1916 /* && IS_TRUE_SYMOP(IC_RIGHT(dic)) */
1918 break; /* found where this temp was defined */
1920 /* if we find an usage then we cannot delete it */
1921 if (IC_LEFT (dic) && IC_LEFT (dic)->key == op->key)
1924 if (IC_RIGHT (dic) && IC_RIGHT (dic)->key == op->key)
1927 if (POINTER_SET (dic) && IC_RESULT (dic)->key == op->key)
1932 return NULL; /* didn't find any assignment to op */
1934 /* we are interested only if defined in far space */
1935 /* or in stack space in case of + & - */
1937 /* if assigned to a non-symbol then don't repack regs */
1938 if (!IS_SYMOP (IC_RIGHT (dic)))
1941 /* if the symbol is volatile then we should not */
1942 if (isOperandVolatile (IC_RIGHT (dic), TRUE))
1944 /* XXX TODO --- should we be passing FALSE to isOperandVolatile()?
1945 What does it mean for an iTemp to be volatile, anyway? Passing
1946 TRUE is more cautious but may prevent possible optimizations */
1948 /* if the symbol is in far space then we should not */
1949 if (isOperandInFarSpace (IC_RIGHT (dic)))
1952 /* for + & - operations make sure that
1953 if it is on the stack it is the same
1954 as one of the three operands */
1955 if ((ic->op == '+' || ic->op == '-') &&
1956 OP_SYMBOL (IC_RIGHT (dic))->onStack)
1959 if (IC_RESULT (ic)->key != IC_RIGHT (dic)->key &&
1960 IC_LEFT (ic)->key != IC_RIGHT (dic)->key &&
1961 IC_RIGHT (ic)->key != IC_RIGHT (dic)->key)
1965 /* now make sure that the right side of dic
1966 is not defined between ic & dic */
1969 iCode *sic = dic->next;
1971 for (; sic != ic; sic = sic->next)
1972 if (IC_RESULT (sic) &&
1973 IC_RESULT (sic)->key == IC_RIGHT (dic)->key)
1980 /*-----------------------------------------------------------------*/
1981 /* reassignAliasedSym - used by packRegsForSupport to replace */
1982 /* redundant iTemp with equivalent symbol */
1983 /*-----------------------------------------------------------------*/
1985 reassignAliasedSym (eBBlock *ebp, iCode *assignment, iCode *use, operand *op)
1988 unsigned oldSymKey, newSymKey;
1990 oldSymKey = op->key;
1991 newSymKey = IC_RIGHT(assignment)->key;
1993 /* only track live ranges of compiler-generated temporaries */
1994 if (!IS_ITEMP(IC_RIGHT(assignment)))
1997 /* update the live-value bitmaps */
1998 for (ic = assignment; ic != use; ic = ic->next) {
1999 bitVectUnSetBit (ic->rlive, oldSymKey);
2001 ic->rlive = bitVectSetBit (ic->rlive, newSymKey);
2004 /* update the sym of the used operand */
2005 OP_SYMBOL(op) = OP_SYMBOL(IC_RIGHT(assignment));
2006 op->key = OP_SYMBOL(op)->key;
2008 /* update the sym's liverange */
2009 if ( OP_LIVETO(op) < ic->seq )
2010 setToRange(op, ic->seq, FALSE);
2012 /* remove the assignment iCode now that its result is unused */
2013 remiCodeFromeBBlock (ebp, assignment);
2014 bitVectUnSetBit(OP_SYMBOL(IC_RESULT(assignment))->defs, assignment->key);
2015 hTabDeleteItem (&iCodehTab, assignment->key, assignment, DELETE_ITEM, NULL);
2019 /*-----------------------------------------------------------------*/
2020 /* packRegsForSupport :- reduce some registers for support calls */
2021 /*-----------------------------------------------------------------*/
2023 packRegsForSupport (iCode * ic, eBBlock * ebp)
2027 /* for the left & right operand :- look to see if the
2028 left was assigned a true symbol in far space in that
2029 case replace them */
2031 if (IS_ITEMP (IC_LEFT (ic)) &&
2032 OP_SYMBOL (IC_LEFT (ic))->liveTo <= ic->seq)
2034 dic = findAssignToSym (IC_LEFT (ic), ic);
2038 /* found it we need to remove it from the block */
2039 reassignAliasedSym (ebp, dic, ic, IC_LEFT(ic));
2044 /* do the same for the right operand */
2045 if (IS_ITEMP (IC_RIGHT (ic)) &&
2046 OP_SYMBOL (IC_RIGHT (ic))->liveTo <= ic->seq)
2048 iCode *dic = findAssignToSym (IC_RIGHT (ic), ic);
2052 /* if this is a subtraction & the result
2053 is a true symbol in far space then don't pack */
2054 if (ic->op == '-' && IS_TRUE_SYMOP (IC_RESULT (dic)))
2056 sym_link *etype = getSpec (operandType (IC_RESULT (dic)));
2057 if (IN_FARSPACE (SPEC_OCLS (etype)))
2060 /* found it we need to remove it from the
2062 reassignAliasedSym (ebp, dic, ic, IC_RIGHT(ic));
2071 #define IS_OP_RUONLY(x) (x && IS_SYMOP(x) && OP_SYMBOL(x)->ruonly)
2074 /*-----------------------------------------------------------------*/
2075 /* packRegsForOneuse : - will reduce some registers for single Use */
2076 /*-----------------------------------------------------------------*/
2078 packRegsForOneuse (iCode * ic, operand * op, eBBlock * ebp)
2083 /* if returning a literal then do nothing */
2087 /* only upto 2 bytes since we cannot predict
2088 the usage of b, & acc */
2089 if (getSize (operandType (op)) > (fReturnSizeMCS51 - 2))
2092 if (ic->op != RETURN &&
2094 !POINTER_SET (ic) &&
2098 if (ic->op == SEND && ic->argreg != 1) return NULL;
2100 /* this routine will mark the a symbol as used in one
2101 instruction use only && if the defintion is local
2102 (ie. within the basic block) && has only one definition &&
2103 that definiion is either a return value from a
2104 function or does not contain any variables in
2106 uses = bitVectCopy (OP_USES (op));
2107 bitVectUnSetBit (uses, ic->key); /* take away this iCode */
2108 if (!bitVectIsZero (uses)) /* has other uses */
2111 /* if it has only one defintion */
2112 if (bitVectnBitsOn (OP_DEFS (op)) > 1)
2113 return NULL; /* has more than one definition */
2115 /* get that definition */
2117 hTabItemWithKey (iCodehTab,
2118 bitVectFirstBit (OP_DEFS (op)))))
2121 /* if that only usage is a cast */
2122 if (dic->op == CAST) {
2123 /* to a bigger type */
2124 if (getSize(OP_SYM_TYPE(IC_RESULT(dic))) >
2125 getSize(OP_SYM_TYPE(IC_RIGHT(dic)))) {
2126 /* than we can not, since we cannot predict the usage of b & acc */
2131 /* found the definition now check if it is local */
2132 if (dic->seq < ebp->fSeq ||
2133 dic->seq > ebp->lSeq)
2134 return NULL; /* non-local */
2136 /* now check if it is the return from
2138 if (dic->op == CALL || dic->op == PCALL)
2140 if (ic->op != SEND && ic->op != RETURN &&
2141 !POINTER_SET(ic) && !POINTER_GET(ic))
2143 OP_SYMBOL (op)->ruonly = 1;
2150 /* otherwise check that the definition does
2151 not contain any symbols in far space */
2152 if (isOperandInFarSpace (IC_LEFT (dic)) ||
2153 isOperandInFarSpace (IC_RIGHT (dic)) ||
2154 IS_OP_RUONLY (IC_LEFT (ic)) ||
2155 IS_OP_RUONLY (IC_RIGHT (ic)))
2160 /* if pointer set then make sure the pointer
2162 if (POINTER_SET (dic) &&
2163 !IS_DATA_PTR (aggrToPtr (operandType (IC_RESULT (dic)), FALSE)))
2166 if (POINTER_GET (dic) &&
2167 !IS_DATA_PTR (aggrToPtr (operandType (IC_LEFT (dic)), FALSE)))
2172 /* also make sure the intervenening instructions
2173 don't have any thing in far space */
2174 for (dic = dic->next; dic && dic != ic && sic != ic; dic = dic->next)
2177 /* if there is an intervening function call then no */
2178 if (dic->op == CALL || dic->op == PCALL)
2180 /* if pointer set then make sure the pointer
2182 if (POINTER_SET (dic) &&
2183 !IS_DATA_PTR (aggrToPtr (operandType (IC_RESULT (dic)), FALSE)))
2186 if (POINTER_GET (dic) &&
2187 !IS_DATA_PTR (aggrToPtr (operandType (IC_LEFT (dic)), FALSE)))
2190 /* if address of & the result is remat the okay */
2191 if (dic->op == ADDRESS_OF &&
2192 OP_SYMBOL (IC_RESULT (dic))->remat)
2195 /* if operand has size of three or more & this
2196 operation is a '*','/' or '%' then 'b' may
2198 if ((dic->op == '%' || dic->op == '/' || dic->op == '*') &&
2199 getSize (operandType (op)) >= 3)
2202 /* if left or right or result is in far space */
2203 if (isOperandInFarSpace (IC_LEFT (dic)) ||
2204 isOperandInFarSpace (IC_RIGHT (dic)) ||
2205 isOperandInFarSpace (IC_RESULT (dic)) ||
2206 IS_OP_RUONLY (IC_LEFT (dic)) ||
2207 IS_OP_RUONLY (IC_RIGHT (dic)) ||
2208 IS_OP_RUONLY (IC_RESULT (dic)))
2212 /* if left or right or result is on stack */
2213 if (isOperandOnStack(IC_LEFT(dic)) ||
2214 isOperandOnStack(IC_RIGHT(dic)) ||
2215 isOperandOnStack(IC_RESULT(dic))) {
2220 OP_SYMBOL (op)->ruonly = 1;
2224 /*-----------------------------------------------------------------*/
2225 /* isBitwiseOptimizable - requirements of JEAN LOUIS VERN */
2226 /*-----------------------------------------------------------------*/
2228 isBitwiseOptimizable (iCode * ic)
2230 sym_link *ltype = getSpec (operandType (IC_LEFT (ic)));
2231 sym_link *rtype = getSpec (operandType (IC_RIGHT (ic)));
2233 /* bitwise operations are considered optimizable
2234 under the following conditions (Jean-Louis VERN)
2246 if (IS_LITERAL(rtype) ||
2247 (IS_BITVAR (ltype) && IN_BITSPACE (SPEC_OCLS (ltype))))
2253 /*-----------------------------------------------------------------*/
2254 /* isCommutativeOp - tests whether this op cares what order its */
2255 /* operands are in */
2256 /*-----------------------------------------------------------------*/
2257 bool isCommutativeOp(unsigned int op)
2259 if (op == '+' || op == '*' || op == EQ_OP ||
2260 op == '^' || op == '|' || op == BITWISEAND)
2266 /*-----------------------------------------------------------------*/
2267 /* operandUsesAcc - determines whether the code generated for this */
2268 /* operand will have to use the accumulator */
2269 /*-----------------------------------------------------------------*/
2270 bool operandUsesAcc(operand *op)
2276 symbol *sym = OP_SYMBOL(op);
2280 return TRUE; /* duh! */
2282 if (IN_STACK(sym->etype) || sym->onStack ||
2283 (SPIL_LOC(op) && SPIL_LOC(op)->onStack))
2284 return TRUE; /* acc is used to calc stack offset */
2289 sym = SPIL_LOC(op); /* if spilled, look at spill location */
2291 return FALSE; /* more checks? */
2295 symspace = SPEC_OCLS(sym->etype);
2297 if (sym->iaccess && symspace->paged)
2298 return TRUE; /* must fetch paged indirect sym via accumulator */
2300 if (IN_BITSPACE(symspace))
2301 return TRUE; /* fetching bit vars uses the accumulator */
2303 if (IN_FARSPACE(symspace) || IN_CODESPACE(symspace))
2304 return TRUE; /* fetched via accumulator and dptr */
2310 /*-----------------------------------------------------------------*/
2311 /* packRegsForAccUse - pack registers for acc use */
2312 /*-----------------------------------------------------------------*/
2314 packRegsForAccUse (iCode * ic)
2318 /* if this is an aggregate, e.g. a one byte char array */
2319 if (IS_AGGREGATE(operandType(IC_RESULT(ic)))) {
2323 /* if we are calling a reentrant function that has stack parameters */
2324 if (ic->op == CALL &&
2325 IFFUNC_ISREENT(operandType(IC_LEFT(ic))) &&
2326 FUNC_HASSTACKPARM(operandType(IC_LEFT(ic))))
2329 if (ic->op == PCALL &&
2330 IFFUNC_ISREENT(operandType(IC_LEFT(ic))->next) &&
2331 FUNC_HASSTACKPARM(operandType(IC_LEFT(ic))->next))
2334 /* if + or - then it has to be one byte result */
2335 if ((ic->op == '+' || ic->op == '-')
2336 && getSize (operandType (IC_RESULT (ic))) > 1)
2339 /* if shift operation make sure right side is not a literal */
2340 if (ic->op == RIGHT_OP &&
2341 (isOperandLiteral (IC_RIGHT (ic)) ||
2342 getSize (operandType (IC_RESULT (ic))) > 1))
2345 if (ic->op == LEFT_OP &&
2346 (isOperandLiteral (IC_RIGHT (ic)) ||
2347 getSize (operandType (IC_RESULT (ic))) > 1))
2350 if (IS_BITWISE_OP (ic) &&
2351 getSize (operandType (IC_RESULT (ic))) > 1)
2355 /* has only one definition */
2356 if (bitVectnBitsOn (OP_DEFS (IC_RESULT (ic))) > 1)
2359 /* has only one use */
2360 if (bitVectnBitsOn (OP_USES (IC_RESULT (ic))) > 1)
2363 /* and the usage immediately follows this iCode */
2364 if (!(uic = hTabItemWithKey (iCodehTab,
2365 bitVectFirstBit (OP_USES (IC_RESULT (ic))))))
2368 if (ic->next != uic)
2371 /* if it is a conditional branch then we definitely can */
2375 if (uic->op == JUMPTABLE)
2378 if (POINTER_SET (uic) &&
2379 getSize (aggrToPtr (operandType (IC_RESULT (uic)), FALSE)) > 1)
2382 /* if the usage is not is an assignment
2383 or an arithmetic / bitwise / shift operation then not */
2384 if (uic->op != '=' &&
2385 !IS_ARITHMETIC_OP (uic) &&
2386 !IS_BITWISE_OP (uic) &&
2387 uic->op != LEFT_OP &&
2388 uic->op != RIGHT_OP)
2391 /* if used in ^ operation then make sure right is not a
2392 literal (WIML: Why is this?) */
2393 if (uic->op == '^' && isOperandLiteral (IC_RIGHT (uic)))
2396 /* if shift operation make sure right side is not a literal */
2397 /* WIML: Why is this? */
2398 if (uic->op == RIGHT_OP &&
2399 (isOperandLiteral (IC_RIGHT (uic)) ||
2400 getSize (operandType (IC_RESULT (uic))) > 1))
2402 if (uic->op == LEFT_OP &&
2403 (isOperandLiteral (IC_RIGHT (uic)) ||
2404 getSize (operandType (IC_RESULT (uic))) > 1))
2407 /* make sure that the result of this icode is not on the
2408 stack, since acc is used to compute stack offset */
2410 if (IS_TRUE_SYMOP (IC_RESULT (uic)) &&
2411 OP_SYMBOL (IC_RESULT (uic))->onStack)
2414 if (isOperandOnStack(IC_RESULT(uic)))
2418 /* if the usage has only one operand then we can */
2419 if (IC_LEFT (uic) == NULL ||
2420 IC_RIGHT (uic) == NULL)
2423 /* if the other operand uses the accumulator then we cannot */
2424 if ( (IC_LEFT(uic)->key == IC_RESULT(ic)->key &&
2425 operandUsesAcc(IC_RIGHT(uic))) ||
2426 (IC_RIGHT(uic)->key == IC_RESULT(ic)->key &&
2427 operandUsesAcc(IC_LEFT(uic))) )
2430 /* make sure this is on the left side if not commutative */
2431 /* except for '-', which has been written to be able to
2432 handle reversed operands */
2433 if (!(isCommutativeOp(ic->op) || ic->op == '-') &&
2434 IC_LEFT (uic)->key != IC_RESULT (ic)->key)
2438 // this is too dangerous and need further restrictions
2441 /* if one of them is a literal then we can */
2442 if ((IC_LEFT (uic) && IS_OP_LITERAL (IC_LEFT (uic))) ||
2443 (IC_RIGHT (uic) && IS_OP_LITERAL (IC_RIGHT (uic))))
2445 OP_SYMBOL (IC_RESULT (ic))->accuse = 1;
2451 OP_SYMBOL (IC_RESULT (ic))->accuse = 1;
2455 /*-----------------------------------------------------------------*/
2456 /* packForPush - hueristics to reduce iCode for pushing */
2457 /*-----------------------------------------------------------------*/
2459 packForPush (iCode * ic, eBBlock ** ebpp, int blockno)
2463 struct eBBlock * ebp=ebpp[blockno];
2465 if (ic->op != IPUSH || !IS_ITEMP (IC_LEFT (ic)))
2468 /* must have only definition & one usage */
2469 if (bitVectnBitsOn (OP_DEFS (IC_LEFT (ic))) != 1 ||
2470 bitVectnBitsOn (OP_USES (IC_LEFT (ic))) != 1)
2473 /* find the definition */
2474 if (!(dic = hTabItemWithKey (iCodehTab,
2475 bitVectFirstBit (OP_DEFS (IC_LEFT (ic))))))
2478 if (dic->op != '=' || POINTER_SET (dic))
2481 if (dic->seq < ebp->fSeq) { // Evelyn did this
2483 for (i=0; i<blockno; i++) {
2484 if (dic->seq >= ebpp[i]->fSeq && dic->seq <= ebpp[i]->lSeq) {
2489 wassert (i!=blockno); // no way to recover from here
2492 if (IS_SYMOP(IC_RIGHT(dic))) {
2493 /* make sure the right side does not have any definitions
2495 dbv = OP_DEFS(IC_RIGHT(dic));
2496 for (lic = ic; lic && lic != dic ; lic = lic->prev) {
2497 if (bitVectBitValue(dbv,lic->key))
2500 /* make sure they have the same type */
2501 if (IS_SPEC(operandType(IC_LEFT(ic))))
2503 sym_link *itype=operandType(IC_LEFT(ic));
2504 sym_link *ditype=operandType(IC_RIGHT(dic));
2506 if (SPEC_USIGN(itype)!=SPEC_USIGN(ditype) ||
2507 SPEC_LONG(itype)!=SPEC_LONG(ditype))
2510 /* extend the live range of replaced operand if needed */
2511 if (OP_SYMBOL(IC_RIGHT(dic))->liveTo < ic->seq) {
2512 OP_SYMBOL(IC_RIGHT(dic))->liveTo = ic->seq;
2514 bitVectUnSetBit(OP_SYMBOL(IC_RESULT(dic))->defs,dic->key);
2517 /* we now we know that it has one & only one def & use
2518 and the that the definition is an assignment */
2519 ReplaceOpWithCheaperOp(&IC_LEFT (ic), IC_RIGHT (dic));
2520 remiCodeFromeBBlock (ebp, dic);
2521 hTabDeleteItem (&iCodehTab, dic->key, dic, DELETE_ITEM, NULL);
2524 /*-----------------------------------------------------------------*/
2525 /* packRegisters - does some transformations to reduce register */
2527 /*-----------------------------------------------------------------*/
2529 packRegisters (eBBlock ** ebpp, int blockno)
2533 eBBlock *ebp=ebpp[blockno];
2540 /* look for assignments of the form */
2541 /* iTempNN = TRueSym (someoperation) SomeOperand */
2543 /* TrueSym := iTempNN:1 */
2544 for (ic = ebp->sch; ic; ic = ic->next)
2546 /* find assignment of the form TrueSym := iTempNN:1 */
2547 if (ic->op == '=' && !POINTER_SET (ic))
2548 change += packRegsForAssign (ic, ebp);
2555 for (ic = ebp->sch; ic; ic = ic->next)
2557 /* if this is an itemp & result of an address of a true sym
2558 then mark this as rematerialisable */
2559 if (ic->op == ADDRESS_OF &&
2560 IS_ITEMP (IC_RESULT (ic)) &&
2561 IS_TRUE_SYMOP (IC_LEFT (ic)) &&
2562 bitVectnBitsOn (OP_DEFS (IC_RESULT (ic))) == 1 &&
2563 !OP_SYMBOL (IC_LEFT (ic))->onStack)
2566 OP_SYMBOL (IC_RESULT (ic))->remat = 1;
2567 OP_SYMBOL (IC_RESULT (ic))->rematiCode = ic;
2568 OP_SYMBOL (IC_RESULT (ic))->usl.spillLoc = NULL;
2572 /* if straight assignment then carry remat flag if
2573 this is the only definition */
2574 if (ic->op == '=' &&
2575 !POINTER_SET (ic) &&
2576 IS_SYMOP (IC_RIGHT (ic)) &&
2577 OP_SYMBOL (IC_RIGHT (ic))->remat &&
2578 !IS_CAST_ICODE(OP_SYMBOL (IC_RIGHT (ic))->rematiCode) &&
2579 bitVectnBitsOn (OP_SYMBOL (IC_RESULT (ic))->defs) <= 1)
2582 OP_SYMBOL (IC_RESULT (ic))->remat =
2583 OP_SYMBOL (IC_RIGHT (ic))->remat;
2584 OP_SYMBOL (IC_RESULT (ic))->rematiCode =
2585 OP_SYMBOL (IC_RIGHT (ic))->rematiCode;
2588 /* if cast to a generic pointer & the pointer being
2589 cast is remat, then we can remat this cast as well */
2590 if (ic->op == CAST &&
2591 IS_SYMOP(IC_RIGHT(ic)) &&
2592 OP_SYMBOL(IC_RIGHT(ic))->remat ) {
2593 sym_link *to_type = operandType(IC_LEFT(ic));
2594 sym_link *from_type = operandType(IC_RIGHT(ic));
2595 if (IS_GENPTR(to_type) && IS_PTR(from_type)) {
2596 OP_SYMBOL (IC_RESULT (ic))->remat = 1;
2597 OP_SYMBOL (IC_RESULT (ic))->rematiCode = ic;
2598 OP_SYMBOL (IC_RESULT (ic))->usl.spillLoc = NULL;
2602 /* if this is a +/- operation with a rematerizable
2603 then mark this as rematerializable as well */
2604 if ((ic->op == '+' || ic->op == '-') &&
2605 (IS_SYMOP (IC_LEFT (ic)) &&
2606 IS_ITEMP (IC_RESULT (ic)) &&
2607 IS_OP_LITERAL (IC_RIGHT (ic))) &&
2608 OP_SYMBOL (IC_LEFT (ic))->remat &&
2609 (!IS_SYMOP (IC_RIGHT (ic)) || !IS_CAST_ICODE(OP_SYMBOL (IC_RIGHT (ic))->rematiCode)) &&
2610 bitVectnBitsOn (OP_DEFS (IC_RESULT (ic))) == 1)
2612 OP_SYMBOL (IC_RESULT (ic))->remat = 1;
2613 OP_SYMBOL (IC_RESULT (ic))->rematiCode = ic;
2614 OP_SYMBOL (IC_RESULT (ic))->usl.spillLoc = NULL;
2617 /* mark the pointer usages */
2618 if (POINTER_SET (ic))
2619 OP_SYMBOL (IC_RESULT (ic))->uptr = 1;
2621 if (POINTER_GET (ic) &&
2622 IS_SYMOP(IC_LEFT (ic)))
2623 OP_SYMBOL (IC_LEFT (ic))->uptr = 1;
2627 /* if we are using a symbol on the stack
2628 then we should say mcs51_ptrRegReq */
2629 if (ic->op == IFX && IS_SYMOP (IC_COND (ic)))
2630 mcs51_ptrRegReq += ((OP_SYMBOL (IC_COND (ic))->onStack ||
2631 OP_SYMBOL (IC_COND (ic))->iaccess) ? 1 : 0);
2632 else if (ic->op == JUMPTABLE && IS_SYMOP (IC_JTCOND (ic)))
2633 mcs51_ptrRegReq += ((OP_SYMBOL (IC_JTCOND (ic))->onStack ||
2634 OP_SYMBOL (IC_JTCOND (ic))->iaccess) ? 1 : 0);
2637 if (IS_SYMOP (IC_LEFT (ic)))
2638 mcs51_ptrRegReq += ((OP_SYMBOL (IC_LEFT (ic))->onStack ||
2639 OP_SYMBOL (IC_LEFT (ic))->iaccess) ? 1 : 0);
2640 if (IS_SYMOP (IC_RIGHT (ic)))
2641 mcs51_ptrRegReq += ((OP_SYMBOL (IC_RIGHT (ic))->onStack ||
2642 OP_SYMBOL (IC_RIGHT (ic))->iaccess) ? 1 : 0);
2643 if (IS_SYMOP (IC_RESULT (ic)))
2644 mcs51_ptrRegReq += ((OP_SYMBOL (IC_RESULT (ic))->onStack ||
2645 OP_SYMBOL (IC_RESULT (ic))->iaccess) ? 1 : 0);
2649 /* if the condition of an if instruction
2650 is defined in the previous instruction and
2651 this is the only usage then
2652 mark the itemp as a conditional */
2653 if ((IS_CONDITIONAL (ic) ||
2654 (IS_BITWISE_OP(ic) && isBitwiseOptimizable (ic))) &&
2655 ic->next && ic->next->op == IFX &&
2656 bitVectnBitsOn (OP_USES(IC_RESULT(ic)))==1 &&
2657 isOperandEqual (IC_RESULT (ic), IC_COND (ic->next)) &&
2658 OP_SYMBOL (IC_RESULT (ic))->liveTo <= ic->next->seq)
2660 OP_SYMBOL (IC_RESULT (ic))->regType = REG_CND;
2664 /* reduce for support function calls */
2665 if (ic->supportRtn || ic->op == '+' || ic->op == '-')
2666 packRegsForSupport (ic, ebp);
2668 /* some cases the redundant moves can
2669 can be eliminated for return statements */
2670 if ((ic->op == RETURN || (ic->op == SEND && ic->argreg == 1)) &&
2671 !isOperandInFarSpace (IC_LEFT (ic)) &&
2672 options.model == MODEL_SMALL) {
2673 packRegsForOneuse (ic, IC_LEFT (ic), ebp);
2676 /* if pointer set & left has a size more than
2677 one and right is not in far space */
2678 if (POINTER_SET (ic) &&
2679 !isOperandInFarSpace (IC_RIGHT (ic)) &&
2680 !OP_SYMBOL (IC_RESULT (ic))->remat &&
2681 !IS_OP_RUONLY (IC_RIGHT (ic)) &&
2682 getSize (aggrToPtr (operandType (IC_RESULT (ic)), FALSE)) > 1)
2683 packRegsForOneuse (ic, IC_RESULT (ic), ebp);
2685 /* if pointer get */
2686 if (POINTER_GET (ic) &&
2687 IS_SYMOP (IC_LEFT (ic)) &&
2688 !isOperandInFarSpace (IC_RESULT (ic)) &&
2689 !OP_SYMBOL (IC_LEFT (ic))->remat &&
2690 !IS_OP_RUONLY (IC_RESULT (ic)) &&
2691 getSize (aggrToPtr (operandType (IC_LEFT (ic)), FALSE)) > 1)
2692 packRegsForOneuse (ic, IC_LEFT (ic), ebp);
2695 /* if this is cast for intergral promotion then
2696 check if only use of the definition of the
2697 operand being casted/ if yes then replace
2698 the result of that arithmetic operation with
2699 this result and get rid of the cast */
2702 sym_link *fromType = operandType (IC_RIGHT (ic));
2703 sym_link *toType = operandType (IC_LEFT (ic));
2705 if (IS_INTEGRAL (fromType) && IS_INTEGRAL (toType) &&
2706 getSize (fromType) != getSize (toType) &&
2707 SPEC_USIGN (fromType) == SPEC_USIGN (toType))
2710 iCode *dic = packRegsForOneuse (ic, IC_RIGHT (ic), ebp);
2713 if (IS_ARITHMETIC_OP (dic))
2715 bitVectUnSetBit(OP_SYMBOL(IC_RESULT(dic))->defs,dic->key);
2716 ReplaceOpWithCheaperOp(&IC_RESULT (dic), IC_RESULT (ic));
2717 remiCodeFromeBBlock (ebp, ic);
2718 bitVectUnSetBit(OP_SYMBOL(IC_RESULT(ic))->defs,ic->key);
2719 hTabDeleteItem (&iCodehTab, ic->key, ic, DELETE_ITEM, NULL);
2720 OP_DEFS(IC_RESULT (dic))=bitVectSetBit (OP_DEFS (IC_RESULT (dic)), dic->key);
2724 OP_SYMBOL (IC_RIGHT (ic))->ruonly = 0;
2730 /* if the type from and type to are the same
2731 then if this is the only use then packit */
2732 if (compareType (operandType (IC_RIGHT (ic)),
2733 operandType (IC_LEFT (ic))) == 1)
2735 iCode *dic = packRegsForOneuse (ic, IC_RIGHT (ic), ebp);
2738 bitVectUnSetBit(OP_SYMBOL(IC_RESULT(dic))->defs,dic->key);
2739 ReplaceOpWithCheaperOp(&IC_RESULT (dic), IC_RESULT (ic));
2740 remiCodeFromeBBlock (ebp, ic);
2741 bitVectUnSetBit(OP_SYMBOL(IC_RESULT(ic))->defs,ic->key);
2742 hTabDeleteItem (&iCodehTab, ic->key, ic, DELETE_ITEM, NULL);
2743 OP_DEFS(IC_RESULT (dic))=bitVectSetBit (OP_DEFS (IC_RESULT (dic)), dic->key);
2751 iTempNN := (some variable in farspace) V1
2756 if (ic->op == IPUSH)
2758 packForPush (ic, ebpp, blockno);
2762 /* pack registers for accumulator use, when the
2763 result of an arithmetic or bit wise operation
2764 has only one use, that use is immediately following
2765 the defintion and the using iCode has only one
2766 operand or has two operands but one is literal &
2767 the result of that operation is not on stack then
2768 we can leave the result of this operation in acc:b
2770 if ((IS_ARITHMETIC_OP (ic)
2771 || IS_CONDITIONAL(ic)
2772 || IS_BITWISE_OP (ic)
2773 || ic->op == LEFT_OP || ic->op == RIGHT_OP || ic->op == CALL
2774 || (ic->op == ADDRESS_OF && isOperandOnStack (IC_LEFT (ic)))
2776 IS_ITEMP (IC_RESULT (ic)) &&
2777 getSize (operandType (IC_RESULT (ic))) <= 2)
2779 packRegsForAccUse (ic);
2783 /*-----------------------------------------------------------------*/
2784 /* assignRegisters - assigns registers to each live range as need */
2785 /*-----------------------------------------------------------------*/
2787 mcs51_assignRegisters (eBBlock ** ebbs, int count)
2792 setToNull ((void *) &_G.funcrUsed);
2793 setToNull ((void *) &_G.totRegAssigned);
2794 mcs51_ptrRegReq = _G.stackExtend = _G.dataExtend = 0;
2797 /* change assignments this will remove some
2798 live ranges reducing some register pressure */
2799 for (i = 0; i < count; i++)
2800 packRegisters (ebbs, i);
2802 if (options.dump_pack)
2803 dumpEbbsToFileExt (DUMP_PACK, ebbs, count);
2805 /* first determine for each live range the number of
2806 registers & the type of registers required for each */
2809 /* and serially allocate registers */
2810 serialRegAssign (ebbs, count);
2815 /* if stack was extended then tell the user */
2818 /* werror(W_TOOMANY_SPILS,"stack", */
2819 /* _G.stackExtend,currFunc->name,""); */
2825 /* werror(W_TOOMANY_SPILS,"data space", */
2826 /* _G.dataExtend,currFunc->name,""); */
2830 /* after that create the register mask
2831 for each of the instruction */
2832 createRegMask (ebbs, count);
2834 /* redo that offsets for stacked automatic variables */
2835 redoStackOffsets ();
2837 if (options.dump_rassgn)
2839 dumpEbbsToFileExt (DUMP_RASSGN, ebbs, count);
2840 dumpLiveRanges (DUMP_LRANGE, liveRanges);
2843 /* do the overlaysegment stuff SDCCmem.c */
2844 doOverlays (ebbs, count);
2846 /* now get back the chain */
2847 ic = iCodeLabelOptimize (iCodeFromeBBlock (ebbs, count));
2851 /* free up any _G.stackSpil locations allocated */
2852 applyToSet (_G.stackSpil, deallocStackSpil);
2854 setToNull ((void **) &_G.stackSpil);
2855 setToNull ((void **) &_G.spiltSet);
2856 /* mark all registers as free */