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) {
1113 // update the registers in use at the start of this icode
1114 for (reg=0; reg<mcs51_nRegs; reg++) {
1115 if (regs8051[reg].isFree) {
1116 ic->riu &= ~(1<<regs8051[reg].offset);
1118 ic->riu |= (1<<regs8051[reg].offset);
1123 /* if this is an ipop that means some live
1124 range will have to be assigned again */
1126 reassignLR (IC_LEFT (ic));
1128 /* if result is present && is a true symbol */
1129 if (IC_RESULT (ic) && ic->op != IFX &&
1130 IS_TRUE_SYMOP (IC_RESULT (ic)))
1131 OP_SYMBOL (IC_RESULT (ic))->allocreq++;
1133 /* take away registers from live
1134 ranges that end at this instruction */
1135 deassignLRs (ic, ebbs[i]);
1137 /* some don't need registers */
1138 if (SKIP_IC2 (ic) ||
1139 ic->op == JUMPTABLE ||
1143 (IC_RESULT (ic) && POINTER_SET (ic)))
1146 /* now we need to allocate registers
1147 only for the result */
1148 if (IC_RESULT (ic)) {
1149 symbol *sym = OP_SYMBOL (IC_RESULT (ic));
1155 /* if it does not need or is spilt
1156 or is already assigned to registers
1157 or will not live beyond this instructions */
1160 bitVectBitValue (_G.regAssigned, sym->key) ||
1161 sym->liveTo <= ic->seq)
1164 /* if some liverange has been spilt at the block level
1165 and this one live beyond this block then spil this
1167 if (_G.blockSpil && sym->liveTo > ebbs[i]->lSeq) {
1171 /* if trying to allocate this will cause
1172 a spill and there is nothing to spill
1173 or this one is rematerializable then
1175 willCS = willCauseSpill (sym->nRegs, sym->regType);
1176 spillable = computeSpillable (ic);
1177 if (sym->remat || (willCS && bitVectIsZero (spillable))) {
1182 /* if it has a spillocation & is used less than
1183 all other live ranges then spill this */
1185 if (sym->usl.spillLoc) {
1186 symbol *leastUsed = leastUsedLR (liveRangesWith (spillable,
1187 allLRs, ebbs[i], ic));
1188 if (leastUsed && leastUsed->used > sym->used) {
1193 /* if none of the liveRanges have a spillLocation then better
1194 to spill this one than anything else already assigned to registers */
1195 if (liveRangesWith(spillable,noSpilLoc,ebbs[i],ic)) {
1196 /* if this is local to this block then we might find a block spil */
1197 if (!(sym->liveFrom >= ebbs[i]->fSeq && sym->liveTo <= ebbs[i]->lSeq)) {
1204 /* if we need ptr regs for the right side
1206 if (POINTER_GET (ic) && IS_SYMOP (IC_LEFT (ic))
1207 && getSize (OP_SYMBOL (IC_LEFT (ic))->type) <= (unsigned int) PTRSIZE) {
1211 /* else we assign registers to it */
1212 _G.regAssigned = bitVectSetBit (_G.regAssigned, sym->key);
1213 _G.totRegAssigned = bitVectSetBit (_G.totRegAssigned, sym->key);
1215 for (j = 0; j < sym->nRegs; j++) {
1216 if (sym->regType == REG_PTR)
1217 sym->regs[j] = getRegPtr (ic, ebbs[i], sym);
1219 sym->regs[j] = getRegGpr (ic, ebbs[i], sym);
1221 /* if the allocation failed which means
1222 this was spilt then break */
1223 if (!sym->regs[j]) {
1228 if (!POINTER_SET(ic) && !POINTER_GET(ic)) {
1229 /* if it shares registers with operands make sure
1230 that they are in the same position */
1231 if (IC_LEFT (ic) && IS_SYMOP (IC_LEFT (ic)) &&
1232 OP_SYMBOL (IC_LEFT (ic))->nRegs) {
1233 positionRegs (OP_SYMBOL (IC_RESULT (ic)),
1234 OP_SYMBOL (IC_LEFT (ic)));
1236 /* do the same for the right operand */
1237 if (IC_RIGHT (ic) && IS_SYMOP (IC_RIGHT (ic)) &&
1238 OP_SYMBOL (IC_RIGHT (ic))->nRegs) {
1239 positionRegs (OP_SYMBOL (IC_RESULT (ic)),
1240 OP_SYMBOL (IC_RIGHT (ic)));
1254 /*-----------------------------------------------------------------*/
1255 /* fillGaps - Try to fill in the Gaps left by Pass1 */
1256 /*-----------------------------------------------------------------*/
1257 static void fillGaps()
1263 if (getenv("DISABLE_FILL_GAPS")) return;
1265 /* look for livernages that was spilt by the allocator */
1266 for (sym = hTabFirstItem(liveRanges,&key) ; sym ;
1267 sym = hTabNextItem(liveRanges,&key)) {
1272 if (!sym->spillA || !sym->clashes || sym->remat) continue ;
1274 /* find the liveRanges this one clashes with, that are
1275 still assigned to registers & mark the registers as used*/
1276 for ( i = 0 ; i < sym->clashes->size ; i ++) {
1280 if (bitVectBitValue(sym->clashes,i) == 0 || /* those that clash with this */
1281 bitVectBitValue(_G.totRegAssigned,i) == 0) /* and are still assigned to registers */
1284 clr = hTabItemWithKey(liveRanges,i);
1287 /* mark these registers as used */
1288 for (k = 0 ; k < clr->nRegs ; k++ )
1289 useReg(clr->regs[k]);
1292 if (willCauseSpill(sym->nRegs,sym->regType)) {
1293 /* NOPE :( clear all registers & and continue */
1298 D(printf("Atemping fillGaps on %s: [",sym->name));
1299 /* THERE IS HOPE !!!! */
1300 for (i=0; i < sym->nRegs ; i++ ) {
1301 if (sym->regType == REG_PTR)
1302 sym->regs[i] = getRegPtrNoSpil ();
1304 sym->regs[i] = getRegGprNoSpil ();
1305 D(printf("%s ", sym->regs[i]->name));
1309 /* For all its definitions check if the registers
1310 allocated needs positioning NOTE: we can position
1311 only ONCE if more than One positioning required
1313 We may need to perform the checks twice; once to
1314 position the registers as needed, the second to
1315 verify any register repositioning is still
1319 for (pass=0; pass<2; pass++) {
1320 D(printf(" checking definitions\n"));
1321 for (i = 0 ; i < sym->defs->size ; i++ ) {
1322 if (bitVectBitValue(sym->defs,i)) {
1324 if (!(ic = hTabItemWithKey(iCodehTab,i))) continue ;
1325 D(printf(" ic->seq = %d\n", ic->seq));
1326 if (SKIP_IC(ic)) continue;
1327 assert(isSymbolEqual(sym,OP_SYMBOL(IC_RESULT(ic)))); /* just making sure */
1328 /* if left is assigned to registers */
1329 if (IS_SYMOP(IC_LEFT(ic)))
1331 D(printf(" left = "));
1332 D(printOperand(IC_LEFT(ic),NULL));
1334 if (IS_SYMOP(IC_LEFT(ic)) &&
1335 bitVectBitValue(_G.totRegAssigned,OP_SYMBOL(IC_LEFT(ic))->key)) {
1336 pdone += (positionRegs(sym,OP_SYMBOL(IC_LEFT(ic)))>0);
1338 if (IS_SYMOP(IC_RIGHT(ic)))
1340 D(printf(" right = "));
1341 D(printOperand(IC_RIGHT(ic),NULL));
1343 if (IS_SYMOP(IC_RIGHT(ic)) &&
1344 bitVectBitValue(_G.totRegAssigned,OP_SYMBOL(IC_RIGHT(ic))->key)) {
1345 pdone += (positionRegs(sym,OP_SYMBOL(IC_RIGHT(ic)))>0);
1347 D(printf(" pdone = %d\n", pdone));
1348 if (pdone > 1) break;
1351 D(printf(" checking uses\n"));
1352 for (i = 0 ; i < sym->uses->size ; i++ ) {
1353 if (bitVectBitValue(sym->uses,i)) {
1355 if (!(ic = hTabItemWithKey(iCodehTab,i))) continue ;
1356 D(printf(" ic->seq = %d\n", ic->seq));
1357 if (SKIP_IC(ic)) continue;
1358 if (POINTER_SET(ic) || POINTER_GET(ic)) continue ;
1360 /* if result is assigned to registers */
1361 if (IS_SYMOP(IC_RESULT(ic)))
1363 D(printf(" result = "));
1364 D(printOperand(IC_RESULT(ic),NULL));
1366 if (IS_SYMOP(IC_RESULT(ic)) &&
1367 bitVectBitValue(_G.totRegAssigned,OP_SYMBOL(IC_RESULT(ic))->key)) {
1368 pdone += (positionRegs(sym,OP_SYMBOL(IC_RESULT(ic)))>0);
1370 D(printf(" pdone = %d\n", pdone));
1371 if (pdone > 1) break;
1374 if (pdone == 0) break; /* second pass only if regs repositioned */
1375 if (pdone > 1) break;
1377 D(printf(" sym->regs = ["));
1378 for (i=0; i < sym->nRegs ; i++ )
1379 D(printf("%s ", sym->regs[i]->name));
1381 /* had to position more than once GIVE UP */
1383 /* UNDO all the changes we made to try this */
1385 for (i=0; i < sym->nRegs ; i++ ) {
1386 sym->regs[i] = NULL;
1389 D(printf ("Fill Gap gave up due to positioning for %s in function %s\n",sym->name, currFunc ? currFunc->name : "UNKNOWN"));
1392 D(printf ("FILLED GAP for %s in function %s\n",sym->name, currFunc ? currFunc->name : "UNKNOWN"));
1393 _G.totRegAssigned = bitVectSetBit(_G.totRegAssigned,sym->key);
1394 sym->isspilt = sym->spillA = 0 ;
1395 sym->usl.spillLoc->allocreq--;
1400 /*-----------------------------------------------------------------*/
1401 /* rUmaskForOp :- returns register mask for an operand */
1402 /*-----------------------------------------------------------------*/
1404 mcs51_rUmaskForOp (operand * op)
1410 /* only temporaries are assigned registers */
1414 sym = OP_SYMBOL (op);
1416 /* if spilt or no registers assigned to it
1418 if (sym->isspilt || !sym->nRegs)
1421 rumask = newBitVect (mcs51_nRegs);
1423 for (j = 0; j < sym->nRegs; j++)
1425 rumask = bitVectSetBit (rumask,
1426 sym->regs[j]->rIdx);
1432 /*-----------------------------------------------------------------*/
1433 /* regsUsedIniCode :- returns bit vector of registers used in iCode */
1434 /*-----------------------------------------------------------------*/
1436 regsUsedIniCode (iCode * ic)
1438 bitVect *rmask = newBitVect (mcs51_nRegs);
1440 /* do the special cases first */
1443 rmask = bitVectUnion (rmask,
1444 mcs51_rUmaskForOp (IC_COND (ic)));
1448 /* for the jumptable */
1449 if (ic->op == JUMPTABLE)
1451 rmask = bitVectUnion (rmask,
1452 mcs51_rUmaskForOp (IC_JTCOND (ic)));
1457 /* of all other cases */
1459 rmask = bitVectUnion (rmask,
1460 mcs51_rUmaskForOp (IC_LEFT (ic)));
1464 rmask = bitVectUnion (rmask,
1465 mcs51_rUmaskForOp (IC_RIGHT (ic)));
1468 rmask = bitVectUnion (rmask,
1469 mcs51_rUmaskForOp (IC_RESULT (ic)));
1475 /*-----------------------------------------------------------------*/
1476 /* createRegMask - for each instruction will determine the regsUsed */
1477 /*-----------------------------------------------------------------*/
1479 createRegMask (eBBlock ** ebbs, int count)
1483 /* for all blocks */
1484 for (i = 0; i < count; i++)
1488 if (ebbs[i]->noPath &&
1489 (ebbs[i]->entryLabel != entryLabel &&
1490 ebbs[i]->entryLabel != returnLabel))
1493 /* for all instructions */
1494 for (ic = ebbs[i]->sch; ic; ic = ic->next)
1499 if (SKIP_IC2 (ic) || !ic->rlive)
1502 /* first mark the registers used in this
1504 ic->rUsed = regsUsedIniCode (ic);
1505 _G.funcrUsed = bitVectUnion (_G.funcrUsed, ic->rUsed);
1507 /* now create the register mask for those
1508 registers that are in use : this is a
1509 super set of ic->rUsed */
1510 ic->rMask = newBitVect (mcs51_nRegs + 1);
1512 /* for all live Ranges alive at this point */
1513 for (j = 1; j < ic->rlive->size; j++)
1518 /* if not alive then continue */
1519 if (!bitVectBitValue (ic->rlive, j))
1522 /* find the live range we are interested in */
1523 if (!(sym = hTabItemWithKey (liveRanges, j)))
1525 werror (E_INTERNAL_ERROR, __FILE__, __LINE__,
1526 "createRegMask cannot find live range");
1527 fprintf(stderr, "\tmissing live range: key=%d\n", j);
1531 /* if no register assigned to it */
1532 if (!sym->nRegs || sym->isspilt)
1535 /* for all the registers allocated to it */
1536 for (k = 0; k < sym->nRegs; k++)
1539 bitVectSetBit (ic->rMask, sym->regs[k]->rIdx);
1545 /*-----------------------------------------------------------------*/
1546 /* rematStr - returns the rematerialized string for a remat var */
1547 /*-----------------------------------------------------------------*/
1549 rematStr (symbol * sym)
1552 iCode *ic = sym->rematiCode;
1557 /* if plus or minus print the right hand side */
1558 if (ic->op == '+' || ic->op == '-')
1560 sprintf (s, "0x%04x %c ", (int) operandLitValue (IC_RIGHT (ic)),
1563 ic = OP_SYMBOL (IC_LEFT (ic))->rematiCode;
1567 /* cast then continue */
1568 if (IS_CAST_ICODE(ic)) {
1569 ic = OP_SYMBOL (IC_RIGHT (ic))->rematiCode;
1572 /* we reached the end */
1573 sprintf (s, "%s", OP_SYMBOL (IC_LEFT (ic))->rname);
1580 /*-----------------------------------------------------------------*/
1581 /* regTypeNum - computes the type & number of registers required */
1582 /*-----------------------------------------------------------------*/
1584 regTypeNum (eBBlock *ebbs)
1590 /* for each live range do */
1591 for (sym = hTabFirstItem (liveRanges, &k); sym;
1592 sym = hTabNextItem (liveRanges, &k))
1595 /* if used zero times then no registers needed */
1596 if ((sym->liveTo - sym->liveFrom) == 0)
1600 /* if the live range is a temporary */
1604 /* if the type is marked as a conditional */
1605 if (sym->regType == REG_CND)
1608 /* if used in return only then we don't
1610 if (sym->ruonly || sym->accuse)
1612 if (IS_AGGREGATE (sym->type) || sym->isptr)
1613 sym->type = aggrToPtr (sym->type, FALSE);
1617 /* if the symbol has only one definition &
1618 that definition is a get_pointer */
1619 if (bitVectnBitsOn (sym->defs) == 1 &&
1620 (ic = hTabItemWithKey (iCodehTab,
1621 bitVectFirstBit (sym->defs))) &&
1624 !IS_BITVAR (sym->etype))
1628 /* and that pointer is remat in data space */
1629 if (IS_SYMOP (IC_LEFT (ic)) &&
1630 OP_SYMBOL (IC_LEFT (ic))->remat &&
1631 !IS_CAST_ICODE(OP_SYMBOL (IC_LEFT (ic))->rematiCode) &&
1632 DCL_TYPE (aggrToPtr (operandType(IC_LEFT(ic)), FALSE)) == POINTER)
1634 /* create a psuedo symbol & force a spil */
1635 symbol *psym = newSymbol (rematStr (OP_SYMBOL (IC_LEFT (ic))), 1);
1636 psym->type = sym->type;
1637 psym->etype = sym->etype;
1639 strcpy (psym->rname, psym->name);
1641 sym->usl.spillLoc = psym;
1642 #if 0 // an alternative fix for bug #480076
1643 /* now this is a useless assignment to itself */
1644 remiCodeFromeBBlock (ebbs, ic);
1646 /* now this really is an assignment to itself, make it so;
1647 it will be optimized out later */
1649 ReplaceOpWithCheaperOp(&IC_RIGHT(ic), IC_RESULT(ic));
1655 /* if in data space or idata space then try to
1656 allocate pointer register */
1660 /* if not then we require registers */
1661 sym->nRegs = ((IS_AGGREGATE (sym->type) || sym->isptr) ?
1662 getSize (sym->type = aggrToPtr (sym->type, FALSE)) :
1663 getSize (sym->type));
1667 fprintf (stderr, "allocated more than 4 or 0 registers for type ");
1668 printTypeChain (sym->type, stderr);
1669 fprintf (stderr, "\n");
1672 /* determine the type of register required */
1673 if (sym->nRegs == 1 &&
1674 IS_PTR (sym->type) &&
1676 sym->regType = REG_PTR;
1678 sym->regType = REG_GPR;
1682 /* for the first run we don't provide */
1683 /* registers for true symbols we will */
1684 /* see how things go */
1690 /*-----------------------------------------------------------------*/
1691 /* freeAllRegs - mark all registers as free */
1692 /*-----------------------------------------------------------------*/
1698 for (i = 0; i < mcs51_nRegs; i++)
1699 regs8051[i].isFree = 1;
1702 /*-----------------------------------------------------------------*/
1703 /* deallocStackSpil - this will set the stack pointer back */
1704 /*-----------------------------------------------------------------*/
1706 DEFSETFUNC (deallocStackSpil)
1714 /*-----------------------------------------------------------------*/
1715 /* farSpacePackable - returns the packable icode for far variables */
1716 /*-----------------------------------------------------------------*/
1718 farSpacePackable (iCode * ic)
1722 /* go thru till we find a definition for the
1723 symbol on the right */
1724 for (dic = ic->prev; dic; dic = dic->prev)
1726 /* if the definition is a call then no */
1727 if ((dic->op == CALL || dic->op == PCALL) &&
1728 IC_RESULT (dic)->key == IC_RIGHT (ic)->key)
1733 /* if shift by unknown amount then not */
1734 if ((dic->op == LEFT_OP || dic->op == RIGHT_OP) &&
1735 IC_RESULT (dic)->key == IC_RIGHT (ic)->key)
1738 /* if pointer get and size > 1 */
1739 if (POINTER_GET (dic) &&
1740 getSize (aggrToPtr (operandType (IC_LEFT (dic)), FALSE)) > 1)
1743 if (POINTER_SET (dic) &&
1744 getSize (aggrToPtr (operandType (IC_RESULT (dic)), FALSE)) > 1)
1749 if (IC_COND (dic) &&
1750 IS_TRUE_SYMOP (IC_COND (dic)) &&
1751 isOperandInFarSpace (IC_COND (dic)))
1754 else if (dic->op == JUMPTABLE)
1756 if (IC_JTCOND (dic) &&
1757 IS_TRUE_SYMOP (IC_JTCOND (dic)) &&
1758 isOperandInFarSpace (IC_JTCOND (dic)))
1763 /* if any three is a true symbol in far space */
1764 if (IC_RESULT (dic) &&
1765 IS_TRUE_SYMOP (IC_RESULT (dic)) &&
1766 isOperandInFarSpace (IC_RESULT (dic)))
1769 if (IC_RIGHT (dic) &&
1770 IS_TRUE_SYMOP (IC_RIGHT (dic)) &&
1771 isOperandInFarSpace (IC_RIGHT (dic)) &&
1772 !isOperandEqual (IC_RIGHT (dic), IC_RESULT (ic)))
1775 if (IC_LEFT (dic) &&
1776 IS_TRUE_SYMOP (IC_LEFT (dic)) &&
1777 isOperandInFarSpace (IC_LEFT (dic)) &&
1778 !isOperandEqual (IC_LEFT (dic), IC_RESULT (ic)))
1782 if (isOperandEqual (IC_RIGHT (ic), IC_RESULT (dic)))
1784 if ((dic->op == LEFT_OP ||
1785 dic->op == RIGHT_OP ||
1787 IS_OP_LITERAL (IC_RIGHT (dic)))
1797 /*-----------------------------------------------------------------*/
1798 /* packRegsForAssign - register reduction for assignment */
1799 /*-----------------------------------------------------------------*/
1801 packRegsForAssign (iCode * ic, eBBlock * ebp)
1805 if (!IS_ITEMP (IC_RIGHT (ic)) ||
1806 OP_SYMBOL (IC_RIGHT (ic))->isind ||
1807 OP_LIVETO (IC_RIGHT (ic)) > ic->seq)
1813 /* if the true symbol is defined in far space or on stack
1814 then we should not since this will increase register pressure */
1815 if (isOperandInFarSpace(IC_RESULT(ic)) && !farSpacePackable(ic)) {
1819 /* find the definition of iTempNN scanning backwards if we find a
1820 a use of the true symbol in before we find the definition then
1822 for (dic = ic->prev; dic; dic = dic->prev)
1825 #if 0 /* jwk: This collides with 1.43 but I really see no need for
1826 this anymore. It fixes bug #716790 and substantially improves
1827 redundant register usage around function calls.
1830 /* if there is a function call then don't pack it */
1831 if ((dic->op == CALL || dic->op == PCALL))
1843 if (IS_SYMOP (IC_COND (dic)) &&
1844 (IC_COND (dic)->key == IC_RESULT (ic)->key ||
1845 IC_COND (dic)->key == IC_RIGHT (ic)->key))
1853 if (IS_TRUE_SYMOP (IC_RESULT (dic)) &&
1854 IS_OP_VOLATILE (IC_RESULT (dic)))
1860 if (IS_SYMOP (IC_RESULT (dic)) &&
1861 IC_RESULT (dic)->key == IC_RIGHT (ic)->key)
1863 if (POINTER_SET (dic))
1869 if (IS_SYMOP (IC_RIGHT (dic)) &&
1870 (IC_RIGHT (dic)->key == IC_RESULT (ic)->key ||
1871 IC_RIGHT (dic)->key == IC_RIGHT (ic)->key))
1877 if (IS_SYMOP (IC_LEFT (dic)) &&
1878 (IC_LEFT (dic)->key == IC_RESULT (ic)->key ||
1879 IC_LEFT (dic)->key == IC_RIGHT (ic)->key))
1885 if (POINTER_SET (dic) &&
1886 IC_RESULT (dic)->key == IC_RESULT (ic)->key)
1895 return 0; /* did not find */
1897 /* if assignment then check that right is not a bit */
1898 if (ASSIGNMENT (dic) && !POINTER_SET (dic))
1900 sym_link *etype = operandType (IC_RIGHT (dic));
1901 if (IS_BITFIELD (etype))
1903 /* if result is a bit too then it's ok */
1904 etype = operandType (IC_RESULT (dic));
1905 if (!IS_BITFIELD (etype))
1909 /* if the result is on stack or iaccess then it must be
1910 the same atleast one of the operands */
1911 if (OP_SYMBOL (IC_RESULT (ic))->onStack ||
1912 OP_SYMBOL (IC_RESULT (ic))->iaccess)
1915 /* the operation has only one symbol
1916 operator then we can pack */
1917 if ((IC_LEFT (dic) && !IS_SYMOP (IC_LEFT (dic))) ||
1918 (IC_RIGHT (dic) && !IS_SYMOP (IC_RIGHT (dic))))
1921 if (!((IC_LEFT (dic) &&
1922 IC_RESULT (ic)->key == IC_LEFT (dic)->key) ||
1924 IC_RESULT (ic)->key == IC_RIGHT (dic)->key)))
1928 /* found the definition */
1929 /* replace the result with the result of */
1930 /* this assignment and remove this assignment */
1931 bitVectUnSetBit(OP_SYMBOL(IC_RESULT(dic))->defs,dic->key);
1932 ReplaceOpWithCheaperOp(&IC_RESULT (dic), IC_RESULT (ic));
1934 if (IS_ITEMP (IC_RESULT (dic)) && OP_SYMBOL (IC_RESULT (dic))->liveFrom > dic->seq)
1936 OP_SYMBOL (IC_RESULT (dic))->liveFrom = dic->seq;
1938 // TODO: and the otherway around?
1940 /* delete from liverange table also
1941 delete from all the points inbetween and the new
1943 for (sic = dic; sic != ic; sic = sic->next)
1945 bitVectUnSetBit (sic->rlive, IC_RESULT (ic)->key);
1946 if (IS_ITEMP (IC_RESULT (dic)))
1947 bitVectSetBit (sic->rlive, IC_RESULT (dic)->key);
1950 remiCodeFromeBBlock (ebp, ic);
1951 bitVectUnSetBit(OP_SYMBOL(IC_RESULT(ic))->defs,ic->key);
1952 hTabDeleteItem (&iCodehTab, ic->key, ic, DELETE_ITEM, NULL);
1953 OP_DEFS(IC_RESULT (dic))=bitVectSetBit (OP_DEFS (IC_RESULT (dic)), dic->key);
1957 /*------------------------------------------------------------------*/
1958 /* findAssignToSym : scanning backwards looks for first assig found */
1959 /*------------------------------------------------------------------*/
1961 findAssignToSym (operand * op, iCode * ic)
1965 /* This routine is used to find sequences like
1967 ...; (intervening ops don't use iTempAA or modify FOO)
1968 blah = blah + iTempAA;
1970 and eliminate the use of iTempAA, freeing up its register for
1975 for (dic = ic->prev; dic; dic = dic->prev)
1978 /* if definition by assignment */
1979 if (dic->op == '=' &&
1980 !POINTER_SET (dic) &&
1981 IC_RESULT (dic)->key == op->key
1982 /* && IS_TRUE_SYMOP(IC_RIGHT(dic)) */
1984 break; /* found where this temp was defined */
1986 /* if we find an usage then we cannot delete it */
1990 if (IC_COND (dic) && IC_COND (dic)->key == op->key)
1993 else if (dic->op == JUMPTABLE)
1995 if (IC_JTCOND (dic) && IC_JTCOND (dic)->key == op->key)
2000 if (IC_LEFT (dic) && IC_LEFT (dic)->key == op->key)
2003 if (IC_RIGHT (dic) && IC_RIGHT (dic)->key == op->key)
2006 if (POINTER_SET (dic) && IC_RESULT (dic)->key == op->key)
2012 return NULL; /* didn't find any assignment to op */
2014 /* we are interested only if defined in far space */
2015 /* or in stack space in case of + & - */
2017 /* if assigned to a non-symbol then don't repack regs */
2018 if (!IS_SYMOP (IC_RIGHT (dic)))
2021 /* if the symbol is volatile then we should not */
2022 if (isOperandVolatile (IC_RIGHT (dic), TRUE))
2024 /* XXX TODO --- should we be passing FALSE to isOperandVolatile()?
2025 What does it mean for an iTemp to be volatile, anyway? Passing
2026 TRUE is more cautious but may prevent possible optimizations */
2028 /* if the symbol is in far space then we should not */
2029 if (isOperandInFarSpace (IC_RIGHT (dic)))
2032 /* for + & - operations make sure that
2033 if it is on the stack it is the same
2034 as one of the three operands */
2035 if ((ic->op == '+' || ic->op == '-') &&
2036 OP_SYMBOL (IC_RIGHT (dic))->onStack)
2039 if (IC_RESULT (ic)->key != IC_RIGHT (dic)->key &&
2040 IC_LEFT (ic)->key != IC_RIGHT (dic)->key &&
2041 IC_RIGHT (ic)->key != IC_RIGHT (dic)->key)
2045 /* now make sure that the right side of dic
2046 is not defined between ic & dic */
2049 iCode *sic = dic->next;
2051 for (; sic != ic; sic = sic->next)
2052 if (IC_RESULT (sic) &&
2053 IC_RESULT (sic)->key == IC_RIGHT (dic)->key)
2060 /*-----------------------------------------------------------------*/
2061 /* reassignAliasedSym - used by packRegsForSupport to replace */
2062 /* redundant iTemp with equivalent symbol */
2063 /*-----------------------------------------------------------------*/
2065 reassignAliasedSym (eBBlock *ebp, iCode *assignment, iCode *use, operand *op)
2068 unsigned oldSymKey, newSymKey;
2070 oldSymKey = op->key;
2071 newSymKey = IC_RIGHT(assignment)->key;
2073 /* only track live ranges of compiler-generated temporaries */
2074 if (!IS_ITEMP(IC_RIGHT(assignment)))
2077 /* update the live-value bitmaps */
2078 for (ic = assignment; ic != use; ic = ic->next) {
2079 bitVectUnSetBit (ic->rlive, oldSymKey);
2081 ic->rlive = bitVectSetBit (ic->rlive, newSymKey);
2084 /* update the sym of the used operand */
2085 OP_SYMBOL(op) = OP_SYMBOL(IC_RIGHT(assignment));
2086 op->key = OP_SYMBOL(op)->key;
2088 /* update the sym's liverange */
2089 if ( OP_LIVETO(op) < ic->seq )
2090 setToRange(op, ic->seq, FALSE);
2092 /* remove the assignment iCode now that its result is unused */
2093 remiCodeFromeBBlock (ebp, assignment);
2094 bitVectUnSetBit(OP_SYMBOL(IC_RESULT(assignment))->defs, assignment->key);
2095 hTabDeleteItem (&iCodehTab, assignment->key, assignment, DELETE_ITEM, NULL);
2099 /*-----------------------------------------------------------------*/
2100 /* packRegsForSupport :- reduce some registers for support calls */
2101 /*-----------------------------------------------------------------*/
2103 packRegsForSupport (iCode * ic, eBBlock * ebp)
2107 /* for the left & right operand :- look to see if the
2108 left was assigned a true symbol in far space in that
2109 case replace them */
2111 if (IS_ITEMP (IC_LEFT (ic)) &&
2112 OP_SYMBOL (IC_LEFT (ic))->liveTo <= ic->seq)
2114 dic = findAssignToSym (IC_LEFT (ic), ic);
2118 /* found it we need to remove it from the block */
2119 reassignAliasedSym (ebp, dic, ic, IC_LEFT(ic));
2124 /* do the same for the right operand */
2125 if (IS_ITEMP (IC_RIGHT (ic)) &&
2126 OP_SYMBOL (IC_RIGHT (ic))->liveTo <= ic->seq)
2128 iCode *dic = findAssignToSym (IC_RIGHT (ic), ic);
2132 /* if this is a subtraction & the result
2133 is a true symbol in far space then don't pack */
2134 if (ic->op == '-' && IS_TRUE_SYMOP (IC_RESULT (dic)))
2136 sym_link *etype = getSpec (operandType (IC_RESULT (dic)));
2137 if (IN_FARSPACE (SPEC_OCLS (etype)))
2140 /* found it we need to remove it from the
2142 reassignAliasedSym (ebp, dic, ic, IC_RIGHT(ic));
2151 #define IS_OP_RUONLY(x) (x && IS_SYMOP(x) && OP_SYMBOL(x)->ruonly)
2154 /*-----------------------------------------------------------------*/
2155 /* packRegsForOneuse : - will reduce some registers for single Use */
2156 /*-----------------------------------------------------------------*/
2158 packRegsForOneuse (iCode * ic, operand * op, eBBlock * ebp)
2163 /* if returning a literal then do nothing */
2167 /* only upto 2 bytes since we cannot predict
2168 the usage of b, & acc */
2169 if (getSize (operandType (op)) > (fReturnSizeMCS51 - 2))
2172 if (ic->op != RETURN &&
2174 !POINTER_SET (ic) &&
2178 if (ic->op == SEND && ic->argreg != 1) return NULL;
2180 /* this routine will mark the a symbol as used in one
2181 instruction use only && if the defintion is local
2182 (ie. within the basic block) && has only one definition &&
2183 that definiion is either a return value from a
2184 function or does not contain any variables in
2186 uses = bitVectCopy (OP_USES (op));
2187 bitVectUnSetBit (uses, ic->key); /* take away this iCode */
2188 if (!bitVectIsZero (uses)) /* has other uses */
2191 /* if it has only one defintion */
2192 if (bitVectnBitsOn (OP_DEFS (op)) > 1)
2193 return NULL; /* has more than one definition */
2195 /* get that definition */
2197 hTabItemWithKey (iCodehTab,
2198 bitVectFirstBit (OP_DEFS (op)))))
2201 /* if that only usage is a cast */
2202 if (dic->op == CAST) {
2203 /* to a bigger type */
2204 if (getSize(OP_SYM_TYPE(IC_RESULT(dic))) >
2205 getSize(OP_SYM_TYPE(IC_RIGHT(dic)))) {
2206 /* than we can not, since we cannot predict the usage of b & acc */
2211 /* found the definition now check if it is local */
2212 if (dic->seq < ebp->fSeq ||
2213 dic->seq > ebp->lSeq)
2214 return NULL; /* non-local */
2216 /* now check if it is the return from
2218 if (dic->op == CALL || dic->op == PCALL)
2220 if (ic->op != SEND && ic->op != RETURN &&
2221 !POINTER_SET(ic) && !POINTER_GET(ic))
2223 OP_SYMBOL (op)->ruonly = 1;
2230 /* otherwise check that the definition does
2231 not contain any symbols in far space */
2232 if (isOperandInFarSpace (IC_LEFT (dic)) ||
2233 isOperandInFarSpace (IC_RIGHT (dic)) ||
2234 IS_OP_RUONLY (IC_LEFT (ic)) ||
2235 IS_OP_RUONLY (IC_RIGHT (ic)))
2240 /* if pointer set then make sure the pointer
2242 if (POINTER_SET (dic) &&
2243 !IS_DATA_PTR (aggrToPtr (operandType (IC_RESULT (dic)), FALSE)))
2246 if (POINTER_GET (dic) &&
2247 !IS_DATA_PTR (aggrToPtr (operandType (IC_LEFT (dic)), FALSE)))
2252 /* also make sure the intervenening instructions
2253 don't have any thing in far space */
2254 for (dic = dic->next; dic && dic != ic && sic != ic; dic = dic->next)
2257 /* if there is an intervening function call then no */
2258 if (dic->op == CALL || dic->op == PCALL)
2260 /* if pointer set then make sure the pointer
2262 if (POINTER_SET (dic) &&
2263 !IS_DATA_PTR (aggrToPtr (operandType (IC_RESULT (dic)), FALSE)))
2266 if (POINTER_GET (dic) &&
2267 !IS_DATA_PTR (aggrToPtr (operandType (IC_LEFT (dic)), FALSE)))
2270 /* if address of & the result is remat the okay */
2271 if (dic->op == ADDRESS_OF &&
2272 OP_SYMBOL (IC_RESULT (dic))->remat)
2275 /* if operand has size of three or more & this
2276 operation is a '*','/' or '%' then 'b' may
2278 if ((dic->op == '%' || dic->op == '/' || dic->op == '*') &&
2279 getSize (operandType (op)) >= 3)
2282 /* if left or right or result is in far space */
2283 if (isOperandInFarSpace (IC_LEFT (dic)) ||
2284 isOperandInFarSpace (IC_RIGHT (dic)) ||
2285 isOperandInFarSpace (IC_RESULT (dic)) ||
2286 IS_OP_RUONLY (IC_LEFT (dic)) ||
2287 IS_OP_RUONLY (IC_RIGHT (dic)) ||
2288 IS_OP_RUONLY (IC_RESULT (dic)))
2292 /* if left or right or result is on stack */
2293 if (isOperandOnStack(IC_LEFT(dic)) ||
2294 isOperandOnStack(IC_RIGHT(dic)) ||
2295 isOperandOnStack(IC_RESULT(dic))) {
2300 OP_SYMBOL (op)->ruonly = 1;
2304 /*-----------------------------------------------------------------*/
2305 /* isBitwiseOptimizable - requirements of JEAN LOUIS VERN */
2306 /*-----------------------------------------------------------------*/
2308 isBitwiseOptimizable (iCode * ic)
2310 sym_link *ltype = getSpec (operandType (IC_LEFT (ic)));
2311 sym_link *rtype = getSpec (operandType (IC_RIGHT (ic)));
2313 /* bitwise operations are considered optimizable
2314 under the following conditions (Jean-Louis VERN)
2326 if (IS_LITERAL(rtype) ||
2327 (IS_BITVAR (ltype) && IN_BITSPACE (SPEC_OCLS (ltype))))
2333 /*-----------------------------------------------------------------*/
2334 /* isCommutativeOp - tests whether this op cares what order its */
2335 /* operands are in */
2336 /*-----------------------------------------------------------------*/
2337 bool isCommutativeOp(unsigned int op)
2339 if (op == '+' || op == '*' || op == EQ_OP ||
2340 op == '^' || op == '|' || op == BITWISEAND)
2346 /*-----------------------------------------------------------------*/
2347 /* operandUsesAcc - determines whether the code generated for this */
2348 /* operand will have to use the accumulator */
2349 /*-----------------------------------------------------------------*/
2350 bool operandUsesAcc(operand *op)
2356 symbol *sym = OP_SYMBOL(op);
2360 return TRUE; /* duh! */
2362 if (IN_STACK(sym->etype) || sym->onStack ||
2363 (SPIL_LOC(op) && SPIL_LOC(op)->onStack))
2364 return TRUE; /* acc is used to calc stack offset */
2369 sym = SPIL_LOC(op); /* if spilled, look at spill location */
2371 return FALSE; /* more checks? */
2375 symspace = SPEC_OCLS(sym->etype);
2377 if (sym->iaccess && symspace->paged)
2378 return TRUE; /* must fetch paged indirect sym via accumulator */
2380 if (IN_BITSPACE(symspace))
2381 return TRUE; /* fetching bit vars uses the accumulator */
2383 if (IN_FARSPACE(symspace) || IN_CODESPACE(symspace))
2384 return TRUE; /* fetched via accumulator and dptr */
2390 /*-----------------------------------------------------------------*/
2391 /* packRegsForAccUse - pack registers for acc use */
2392 /*-----------------------------------------------------------------*/
2394 packRegsForAccUse (iCode * ic)
2398 /* if this is an aggregate, e.g. a one byte char array */
2399 if (IS_AGGREGATE(operandType(IC_RESULT(ic)))) {
2403 /* if we are calling a reentrant function that has stack parameters */
2404 if (ic->op == CALL &&
2405 IFFUNC_ISREENT(operandType(IC_LEFT(ic))) &&
2406 FUNC_HASSTACKPARM(operandType(IC_LEFT(ic))))
2409 if (ic->op == PCALL &&
2410 IFFUNC_ISREENT(operandType(IC_LEFT(ic))->next) &&
2411 FUNC_HASSTACKPARM(operandType(IC_LEFT(ic))->next))
2414 /* if + or - then it has to be one byte result */
2415 if ((ic->op == '+' || ic->op == '-')
2416 && getSize (operandType (IC_RESULT (ic))) > 1)
2419 /* if shift operation make sure right side is not a literal */
2420 if (ic->op == RIGHT_OP &&
2421 (isOperandLiteral (IC_RIGHT (ic)) ||
2422 getSize (operandType (IC_RESULT (ic))) > 1))
2425 if (ic->op == LEFT_OP &&
2426 (isOperandLiteral (IC_RIGHT (ic)) ||
2427 getSize (operandType (IC_RESULT (ic))) > 1))
2430 if (IS_BITWISE_OP (ic) &&
2431 getSize (operandType (IC_RESULT (ic))) > 1)
2435 /* has only one definition */
2436 if (bitVectnBitsOn (OP_DEFS (IC_RESULT (ic))) > 1)
2439 /* has only one use */
2440 if (bitVectnBitsOn (OP_USES (IC_RESULT (ic))) > 1)
2443 /* and the usage immediately follows this iCode */
2444 if (!(uic = hTabItemWithKey (iCodehTab,
2445 bitVectFirstBit (OP_USES (IC_RESULT (ic))))))
2448 if (ic->next != uic)
2451 /* if it is a conditional branch then we definitely can */
2455 if (uic->op == JUMPTABLE)
2458 if (POINTER_SET (uic) &&
2459 getSize (aggrToPtr (operandType (IC_RESULT (uic)), FALSE)) > 1)
2462 /* if the usage is not is an assignment
2463 or an arithmetic / bitwise / shift operation then not */
2464 if (uic->op != '=' &&
2465 !IS_ARITHMETIC_OP (uic) &&
2466 !IS_BITWISE_OP (uic) &&
2467 uic->op != LEFT_OP &&
2468 uic->op != RIGHT_OP)
2471 /* if used in ^ operation then make sure right is not a
2472 literal (WIML: Why is this?) */
2473 if (uic->op == '^' && isOperandLiteral (IC_RIGHT (uic)))
2476 /* if shift operation make sure right side is not a literal */
2477 /* WIML: Why is this? */
2478 if (uic->op == RIGHT_OP &&
2479 (isOperandLiteral (IC_RIGHT (uic)) ||
2480 getSize (operandType (IC_RESULT (uic))) > 1))
2482 if (uic->op == LEFT_OP &&
2483 (isOperandLiteral (IC_RIGHT (uic)) ||
2484 getSize (operandType (IC_RESULT (uic))) > 1))
2487 /* make sure that the result of this icode is not on the
2488 stack, since acc is used to compute stack offset */
2490 if (IS_TRUE_SYMOP (IC_RESULT (uic)) &&
2491 OP_SYMBOL (IC_RESULT (uic))->onStack)
2494 if (isOperandOnStack(IC_RESULT(uic)))
2498 /* if the usage has only one operand then we can */
2499 if (IC_LEFT (uic) == NULL ||
2500 IC_RIGHT (uic) == NULL)
2503 /* if the other operand uses the accumulator then we cannot */
2504 if ( (IC_LEFT(uic)->key == IC_RESULT(ic)->key &&
2505 operandUsesAcc(IC_RIGHT(uic))) ||
2506 (IC_RIGHT(uic)->key == IC_RESULT(ic)->key &&
2507 operandUsesAcc(IC_LEFT(uic))) )
2510 /* make sure this is on the left side if not commutative */
2511 /* except for '-', which has been written to be able to
2512 handle reversed operands */
2513 if (!(isCommutativeOp(ic->op) || ic->op == '-') &&
2514 IC_LEFT (uic)->key != IC_RESULT (ic)->key)
2518 // this is too dangerous and need further restrictions
2521 /* if one of them is a literal then we can */
2522 if ((IC_LEFT (uic) && IS_OP_LITERAL (IC_LEFT (uic))) ||
2523 (IC_RIGHT (uic) && IS_OP_LITERAL (IC_RIGHT (uic))))
2525 OP_SYMBOL (IC_RESULT (ic))->accuse = 1;
2531 OP_SYMBOL (IC_RESULT (ic))->accuse = 1;
2535 /*-----------------------------------------------------------------*/
2536 /* packForPush - hueristics to reduce iCode for pushing */
2537 /*-----------------------------------------------------------------*/
2539 packForPush (iCode * ic, eBBlock ** ebpp, int blockno)
2543 struct eBBlock * ebp=ebpp[blockno];
2545 if (ic->op != IPUSH || !IS_ITEMP (IC_LEFT (ic)))
2548 /* must have only definition & one usage */
2549 if (bitVectnBitsOn (OP_DEFS (IC_LEFT (ic))) != 1 ||
2550 bitVectnBitsOn (OP_USES (IC_LEFT (ic))) != 1)
2553 /* find the definition */
2554 if (!(dic = hTabItemWithKey (iCodehTab,
2555 bitVectFirstBit (OP_DEFS (IC_LEFT (ic))))))
2558 if (dic->op != '=' || POINTER_SET (dic))
2561 if (dic->seq < ebp->fSeq) { // Evelyn did this
2563 for (i=0; i<blockno; i++) {
2564 if (dic->seq >= ebpp[i]->fSeq && dic->seq <= ebpp[i]->lSeq) {
2569 wassert (i!=blockno); // no way to recover from here
2572 if (IS_SYMOP(IC_RIGHT(dic))) {
2573 /* make sure the right side does not have any definitions
2575 dbv = OP_DEFS(IC_RIGHT(dic));
2576 for (lic = ic; lic && lic != dic ; lic = lic->prev) {
2577 if (bitVectBitValue(dbv,lic->key))
2580 /* make sure they have the same type */
2581 if (IS_SPEC(operandType(IC_LEFT(ic))))
2583 sym_link *itype=operandType(IC_LEFT(ic));
2584 sym_link *ditype=operandType(IC_RIGHT(dic));
2586 if (SPEC_USIGN(itype)!=SPEC_USIGN(ditype) ||
2587 SPEC_LONG(itype)!=SPEC_LONG(ditype))
2590 /* extend the live range of replaced operand if needed */
2591 if (OP_SYMBOL(IC_RIGHT(dic))->liveTo < ic->seq) {
2592 OP_SYMBOL(IC_RIGHT(dic))->liveTo = ic->seq;
2594 bitVectUnSetBit(OP_SYMBOL(IC_RESULT(dic))->defs,dic->key);
2597 /* we now we know that it has one & only one def & use
2598 and the that the definition is an assignment */
2599 ReplaceOpWithCheaperOp(&IC_LEFT (ic), IC_RIGHT (dic));
2600 remiCodeFromeBBlock (ebp, dic);
2601 hTabDeleteItem (&iCodehTab, dic->key, dic, DELETE_ITEM, NULL);
2604 /*-----------------------------------------------------------------*/
2605 /* packRegisters - does some transformations to reduce register */
2607 /*-----------------------------------------------------------------*/
2609 packRegisters (eBBlock ** ebpp, int blockno)
2613 eBBlock *ebp=ebpp[blockno];
2620 /* look for assignments of the form */
2621 /* iTempNN = TRueSym (someoperation) SomeOperand */
2623 /* TrueSym := iTempNN:1 */
2624 for (ic = ebp->sch; ic; ic = ic->next)
2626 /* find assignment of the form TrueSym := iTempNN:1 */
2627 if (ic->op == '=' && !POINTER_SET (ic))
2628 change += packRegsForAssign (ic, ebp);
2635 for (ic = ebp->sch; ic; ic = ic->next)
2637 /* if this is an itemp & result of an address of a true sym
2638 then mark this as rematerialisable */
2639 if (ic->op == ADDRESS_OF &&
2640 IS_ITEMP (IC_RESULT (ic)) &&
2641 IS_TRUE_SYMOP (IC_LEFT (ic)) &&
2642 bitVectnBitsOn (OP_DEFS (IC_RESULT (ic))) == 1 &&
2643 !OP_SYMBOL (IC_LEFT (ic))->onStack)
2646 OP_SYMBOL (IC_RESULT (ic))->remat = 1;
2647 OP_SYMBOL (IC_RESULT (ic))->rematiCode = ic;
2648 OP_SYMBOL (IC_RESULT (ic))->usl.spillLoc = NULL;
2652 /* if straight assignment then carry remat flag if
2653 this is the only definition */
2654 if (ic->op == '=' &&
2655 !POINTER_SET (ic) &&
2656 IS_SYMOP (IC_RIGHT (ic)) &&
2657 OP_SYMBOL (IC_RIGHT (ic))->remat &&
2658 !IS_CAST_ICODE(OP_SYMBOL (IC_RIGHT (ic))->rematiCode) &&
2659 bitVectnBitsOn (OP_SYMBOL (IC_RESULT (ic))->defs) <= 1)
2662 OP_SYMBOL (IC_RESULT (ic))->remat =
2663 OP_SYMBOL (IC_RIGHT (ic))->remat;
2664 OP_SYMBOL (IC_RESULT (ic))->rematiCode =
2665 OP_SYMBOL (IC_RIGHT (ic))->rematiCode;
2668 /* if cast to a generic pointer & the pointer being
2669 cast is remat, then we can remat this cast as well */
2670 if (ic->op == CAST &&
2671 IS_SYMOP(IC_RIGHT(ic)) &&
2672 OP_SYMBOL(IC_RIGHT(ic))->remat &&
2673 bitVectnBitsOn (OP_DEFS (IC_RESULT (ic))) == 1) {
2674 sym_link *to_type = operandType(IC_LEFT(ic));
2675 sym_link *from_type = operandType(IC_RIGHT(ic));
2676 if (IS_GENPTR(to_type) && IS_PTR(from_type)) {
2677 OP_SYMBOL (IC_RESULT (ic))->remat = 1;
2678 OP_SYMBOL (IC_RESULT (ic))->rematiCode = ic;
2679 OP_SYMBOL (IC_RESULT (ic))->usl.spillLoc = NULL;
2683 /* if this is a +/- operation with a rematerizable
2684 then mark this as rematerializable as well */
2685 if ((ic->op == '+' || ic->op == '-') &&
2686 (IS_SYMOP (IC_LEFT (ic)) &&
2687 IS_ITEMP (IC_RESULT (ic)) &&
2688 IS_OP_LITERAL (IC_RIGHT (ic))) &&
2689 OP_SYMBOL (IC_LEFT (ic))->remat &&
2690 (!IS_SYMOP (IC_RIGHT (ic)) || !IS_CAST_ICODE(OP_SYMBOL (IC_RIGHT (ic))->rematiCode)) &&
2691 bitVectnBitsOn (OP_DEFS (IC_RESULT (ic))) == 1)
2693 OP_SYMBOL (IC_RESULT (ic))->remat = 1;
2694 OP_SYMBOL (IC_RESULT (ic))->rematiCode = ic;
2695 OP_SYMBOL (IC_RESULT (ic))->usl.spillLoc = NULL;
2698 /* mark the pointer usages */
2699 if (POINTER_SET (ic))
2700 OP_SYMBOL (IC_RESULT (ic))->uptr = 1;
2702 if (POINTER_GET (ic) &&
2703 IS_SYMOP(IC_LEFT (ic)))
2704 OP_SYMBOL (IC_LEFT (ic))->uptr = 1;
2708 /* if we are using a symbol on the stack
2709 then we should say mcs51_ptrRegReq */
2710 if (ic->op == IFX && IS_SYMOP (IC_COND (ic)))
2711 mcs51_ptrRegReq += ((OP_SYMBOL (IC_COND (ic))->onStack ||
2712 OP_SYMBOL (IC_COND (ic))->iaccess) ? 1 : 0);
2713 else if (ic->op == JUMPTABLE && IS_SYMOP (IC_JTCOND (ic)))
2714 mcs51_ptrRegReq += ((OP_SYMBOL (IC_JTCOND (ic))->onStack ||
2715 OP_SYMBOL (IC_JTCOND (ic))->iaccess) ? 1 : 0);
2718 if (IS_SYMOP (IC_LEFT (ic)))
2719 mcs51_ptrRegReq += ((OP_SYMBOL (IC_LEFT (ic))->onStack ||
2720 OP_SYMBOL (IC_LEFT (ic))->iaccess) ? 1 : 0);
2721 if (IS_SYMOP (IC_RIGHT (ic)))
2722 mcs51_ptrRegReq += ((OP_SYMBOL (IC_RIGHT (ic))->onStack ||
2723 OP_SYMBOL (IC_RIGHT (ic))->iaccess) ? 1 : 0);
2724 if (IS_SYMOP (IC_RESULT (ic)))
2725 mcs51_ptrRegReq += ((OP_SYMBOL (IC_RESULT (ic))->onStack ||
2726 OP_SYMBOL (IC_RESULT (ic))->iaccess) ? 1 : 0);
2730 /* if the condition of an if instruction
2731 is defined in the previous instruction and
2732 this is the only usage then
2733 mark the itemp as a conditional */
2734 if ((IS_CONDITIONAL (ic) ||
2735 (IS_BITWISE_OP(ic) && isBitwiseOptimizable (ic))) &&
2736 ic->next && ic->next->op == IFX &&
2737 bitVectnBitsOn (OP_USES(IC_RESULT(ic)))==1 &&
2738 isOperandEqual (IC_RESULT (ic), IC_COND (ic->next)) &&
2739 OP_SYMBOL (IC_RESULT (ic))->liveTo <= ic->next->seq)
2741 OP_SYMBOL (IC_RESULT (ic))->regType = REG_CND;
2745 /* reduce for support function calls */
2746 if (ic->supportRtn || ic->op == '+' || ic->op == '-')
2747 packRegsForSupport (ic, ebp);
2749 /* some cases the redundant moves can
2750 can be eliminated for return statements */
2751 if ((ic->op == RETURN || (ic->op == SEND && ic->argreg == 1)) &&
2752 !isOperandInFarSpace (IC_LEFT (ic)) &&
2753 options.model == MODEL_SMALL) {
2754 packRegsForOneuse (ic, IC_LEFT (ic), ebp);
2757 /* if pointer set & left has a size more than
2758 one and right is not in far space */
2759 if (POINTER_SET (ic) &&
2760 !isOperandInFarSpace (IC_RIGHT (ic)) &&
2761 !OP_SYMBOL (IC_RESULT (ic))->remat &&
2762 !IS_OP_RUONLY (IC_RIGHT (ic)) &&
2763 getSize (aggrToPtr (operandType (IC_RESULT (ic)), FALSE)) > 1)
2764 packRegsForOneuse (ic, IC_RESULT (ic), ebp);
2766 /* if pointer get */
2767 if (POINTER_GET (ic) &&
2768 IS_SYMOP (IC_LEFT (ic)) &&
2769 !isOperandInFarSpace (IC_RESULT (ic)) &&
2770 !OP_SYMBOL (IC_LEFT (ic))->remat &&
2771 !IS_OP_RUONLY (IC_RESULT (ic)) &&
2772 getSize (aggrToPtr (operandType (IC_LEFT (ic)), FALSE)) > 1)
2773 packRegsForOneuse (ic, IC_LEFT (ic), ebp);
2776 /* if this is cast for intergral promotion then
2777 check if only use of the definition of the
2778 operand being casted/ if yes then replace
2779 the result of that arithmetic operation with
2780 this result and get rid of the cast */
2783 sym_link *fromType = operandType (IC_RIGHT (ic));
2784 sym_link *toType = operandType (IC_LEFT (ic));
2786 if (IS_INTEGRAL (fromType) && IS_INTEGRAL (toType) &&
2787 getSize (fromType) != getSize (toType) &&
2788 SPEC_USIGN (fromType) == SPEC_USIGN (toType))
2791 iCode *dic = packRegsForOneuse (ic, IC_RIGHT (ic), ebp);
2794 if (IS_ARITHMETIC_OP (dic))
2796 bitVectUnSetBit(OP_SYMBOL(IC_RESULT(dic))->defs,dic->key);
2797 ReplaceOpWithCheaperOp(&IC_RESULT (dic), IC_RESULT (ic));
2798 remiCodeFromeBBlock (ebp, ic);
2799 bitVectUnSetBit(OP_SYMBOL(IC_RESULT(ic))->defs,ic->key);
2800 hTabDeleteItem (&iCodehTab, ic->key, ic, DELETE_ITEM, NULL);
2801 OP_DEFS(IC_RESULT (dic))=bitVectSetBit (OP_DEFS (IC_RESULT (dic)), dic->key);
2805 OP_SYMBOL (IC_RIGHT (ic))->ruonly = 0;
2811 /* if the type from and type to are the same
2812 then if this is the only use then packit */
2813 if (compareType (operandType (IC_RIGHT (ic)),
2814 operandType (IC_LEFT (ic))) == 1)
2816 iCode *dic = packRegsForOneuse (ic, IC_RIGHT (ic), ebp);
2819 bitVectUnSetBit(OP_SYMBOL(IC_RESULT(dic))->defs,dic->key);
2820 ReplaceOpWithCheaperOp(&IC_RESULT (dic), IC_RESULT (ic));
2821 remiCodeFromeBBlock (ebp, ic);
2822 bitVectUnSetBit(OP_SYMBOL(IC_RESULT(ic))->defs,ic->key);
2823 hTabDeleteItem (&iCodehTab, ic->key, ic, DELETE_ITEM, NULL);
2824 OP_DEFS(IC_RESULT (dic))=bitVectSetBit (OP_DEFS (IC_RESULT (dic)), dic->key);
2832 iTempNN := (some variable in farspace) V1
2837 if (ic->op == IPUSH)
2839 packForPush (ic, ebpp, blockno);
2843 /* pack registers for accumulator use, when the
2844 result of an arithmetic or bit wise operation
2845 has only one use, that use is immediately following
2846 the defintion and the using iCode has only one
2847 operand or has two operands but one is literal &
2848 the result of that operation is not on stack then
2849 we can leave the result of this operation in acc:b
2851 if ((IS_ARITHMETIC_OP (ic)
2852 || IS_CONDITIONAL(ic)
2853 || IS_BITWISE_OP (ic)
2854 || ic->op == LEFT_OP || ic->op == RIGHT_OP || ic->op == CALL
2855 || (ic->op == ADDRESS_OF && isOperandOnStack (IC_LEFT (ic)))
2857 IS_ITEMP (IC_RESULT (ic)) &&
2858 getSize (operandType (IC_RESULT (ic))) <= 2)
2860 packRegsForAccUse (ic);
2864 /*-----------------------------------------------------------------*/
2865 /* assignRegisters - assigns registers to each live range as need */
2866 /*-----------------------------------------------------------------*/
2868 mcs51_assignRegisters (eBBlock ** ebbs, int count)
2873 setToNull ((void *) &_G.funcrUsed);
2874 setToNull ((void *) &_G.regAssigned);
2875 setToNull ((void *) &_G.totRegAssigned);
2876 mcs51_ptrRegReq = _G.stackExtend = _G.dataExtend = 0;
2879 /* change assignments this will remove some
2880 live ranges reducing some register pressure */
2882 for (i = 0; i < count; i++)
2883 packRegisters (ebbs, i);
2886 if (options.dump_pack)
2887 dumpEbbsToFileExt (DUMP_PACK, ebbs, count);
2889 /* first determine for each live range the number of
2890 registers & the type of registers required for each */
2893 /* and serially allocate registers */
2894 serialRegAssign (ebbs, count);
2897 //setToNull ((void *) &_G.regAssigned);
2898 //setToNull ((void *) &_G.totRegAssigned);
2901 /* if stack was extended then tell the user */
2904 /* werror(W_TOOMANY_SPILS,"stack", */
2905 /* _G.stackExtend,currFunc->name,""); */
2911 /* werror(W_TOOMANY_SPILS,"data space", */
2912 /* _G.dataExtend,currFunc->name,""); */
2916 /* after that create the register mask
2917 for each of the instruction */
2918 createRegMask (ebbs, count);
2920 /* redo that offsets for stacked automatic variables */
2922 redoStackOffsets ();
2925 if (options.dump_rassgn)
2927 dumpEbbsToFileExt (DUMP_RASSGN, ebbs, count);
2928 dumpLiveRanges (DUMP_LRANGE, liveRanges);
2931 /* do the overlaysegment stuff SDCCmem.c */
2932 doOverlays (ebbs, count);
2934 /* now get back the chain */
2935 ic = iCodeLabelOptimize (iCodeFromeBBlock (ebbs, count));
2939 /* free up any _G.stackSpil locations allocated */
2940 applyToSet (_G.stackSpil, deallocStackSpil);
2942 setToNull ((void *) &_G.stackSpil);
2943 setToNull ((void *) &_G.spiltSet);
2944 /* mark all registers as free */