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 it shares registers with operands make sure
1229 that they are in the same position */
1230 if (IC_LEFT (ic) && IS_SYMOP (IC_LEFT (ic)) &&
1231 OP_SYMBOL (IC_LEFT (ic))->nRegs && ic->op != '=') {
1232 positionRegs (OP_SYMBOL (IC_RESULT (ic)),
1233 OP_SYMBOL (IC_LEFT (ic)));
1235 /* do the same for the right operand */
1236 if (IC_RIGHT (ic) && IS_SYMOP (IC_RIGHT (ic)) &&
1237 OP_SYMBOL (IC_RIGHT (ic))->nRegs) {
1238 positionRegs (OP_SYMBOL (IC_RESULT (ic)),
1239 OP_SYMBOL (IC_RIGHT (ic)));
1252 /*-----------------------------------------------------------------*/
1253 /* fillGaps - Try to fill in the Gaps left by Pass1 */
1254 /*-----------------------------------------------------------------*/
1255 static void fillGaps()
1260 if (getenv("DISABLE_FILL_GAPS")) return;
1262 /* look for livernages that was spilt by the allocator */
1263 for (sym = hTabFirstItem(liveRanges,&key) ; sym ;
1264 sym = hTabNextItem(liveRanges,&key)) {
1269 if (!sym->spillA || !sym->clashes || sym->remat) continue ;
1271 /* find the liveRanges this one clashes with, that are
1272 still assigned to registers & mark the registers as used*/
1273 for ( i = 0 ; i < sym->clashes->size ; i ++) {
1277 if (bitVectBitValue(sym->clashes,i) == 0 || /* those that clash with this */
1278 bitVectBitValue(_G.totRegAssigned,i) == 0) /* and are still assigned to registers */
1281 clr = hTabItemWithKey(liveRanges,i);
1284 /* mark these registers as used */
1285 for (k = 0 ; k < clr->nRegs ; k++ )
1286 useReg(clr->regs[k]);
1289 if (willCauseSpill(sym->nRegs,sym->regType)) {
1290 /* NOPE :( clear all registers & and continue */
1295 /* THERE IS HOPE !!!! */
1296 for (i=0; i < sym->nRegs ; i++ ) {
1297 if (sym->regType == REG_PTR)
1298 sym->regs[i] = getRegPtrNoSpil ();
1300 sym->regs[i] = getRegGprNoSpil ();
1303 /* for all its definitions check if the registers
1304 allocated needs positioning NOTE: we can position
1305 only ONCE if more than One positioning required
1308 for (i = 0 ; i < sym->defs->size ; i++ ) {
1309 if (bitVectBitValue(sym->defs,i)) {
1311 if (!(ic = hTabItemWithKey(iCodehTab,i))) continue ;
1312 if (SKIP_IC(ic)) continue;
1313 assert(isSymbolEqual(sym,OP_SYMBOL(IC_RESULT(ic)))); /* just making sure */
1314 /* if left is assigned to registers */
1315 if (IS_SYMOP(IC_LEFT(ic)) &&
1316 bitVectBitValue(_G.totRegAssigned,OP_SYMBOL(IC_LEFT(ic))->key)) {
1317 pdone += positionRegs(sym,OP_SYMBOL(IC_LEFT(ic)));
1319 if (IS_SYMOP(IC_RIGHT(ic)) &&
1320 bitVectBitValue(_G.totRegAssigned,OP_SYMBOL(IC_RIGHT(ic))->key)) {
1321 pdone += positionRegs(sym,OP_SYMBOL(IC_RIGHT(ic)));
1323 if (pdone > 1) break;
1326 for (i = 0 ; i < sym->uses->size ; i++ ) {
1327 if (bitVectBitValue(sym->uses,i)) {
1329 if (!(ic = hTabItemWithKey(iCodehTab,i))) continue ;
1330 if (SKIP_IC(ic)) continue;
1331 if (!IS_ASSIGN_ICODE(ic)) continue ;
1333 /* if result is assigned to registers */
1334 if (IS_SYMOP(IC_RESULT(ic)) &&
1335 bitVectBitValue(_G.totRegAssigned,OP_SYMBOL(IC_RESULT(ic))->key)) {
1336 pdone += positionRegs(sym,OP_SYMBOL(IC_RESULT(ic)));
1338 if (pdone > 1) break;
1341 /* had to position more than once GIVE UP */
1343 /* UNDO all the changes we made to try this */
1345 for (i=0; i < sym->nRegs ; i++ ) {
1346 sym->regs[i] = NULL;
1349 D(printf ("Fill Gap gave up due to positioning for %s in function %s\n",sym->name, currFunc ? currFunc->name : "UNKNOWN"));
1352 D(printf ("FILLED GAP for %s in function %s\n",sym->name, currFunc ? currFunc->name : "UNKNOWN"));
1353 _G.totRegAssigned = bitVectSetBit(_G.totRegAssigned,sym->key);
1354 sym->isspilt = sym->spillA = 0 ;
1355 sym->usl.spillLoc->allocreq--;
1360 /*-----------------------------------------------------------------*/
1361 /* rUmaskForOp :- returns register mask for an operand */
1362 /*-----------------------------------------------------------------*/
1364 mcs51_rUmaskForOp (operand * op)
1370 /* only temporaries are assigned registers */
1374 sym = OP_SYMBOL (op);
1376 /* if spilt or no registers assigned to it
1378 if (sym->isspilt || !sym->nRegs)
1381 rumask = newBitVect (mcs51_nRegs);
1383 for (j = 0; j < sym->nRegs; j++)
1385 rumask = bitVectSetBit (rumask,
1386 sym->regs[j]->rIdx);
1392 /*-----------------------------------------------------------------*/
1393 /* regsUsedIniCode :- returns bit vector of registers used in iCode */
1394 /*-----------------------------------------------------------------*/
1396 regsUsedIniCode (iCode * ic)
1398 bitVect *rmask = newBitVect (mcs51_nRegs);
1400 /* do the special cases first */
1403 rmask = bitVectUnion (rmask,
1404 mcs51_rUmaskForOp (IC_COND (ic)));
1408 /* for the jumptable */
1409 if (ic->op == JUMPTABLE)
1411 rmask = bitVectUnion (rmask,
1412 mcs51_rUmaskForOp (IC_JTCOND (ic)));
1417 /* of all other cases */
1419 rmask = bitVectUnion (rmask,
1420 mcs51_rUmaskForOp (IC_LEFT (ic)));
1424 rmask = bitVectUnion (rmask,
1425 mcs51_rUmaskForOp (IC_RIGHT (ic)));
1428 rmask = bitVectUnion (rmask,
1429 mcs51_rUmaskForOp (IC_RESULT (ic)));
1435 /*-----------------------------------------------------------------*/
1436 /* createRegMask - for each instruction will determine the regsUsed */
1437 /*-----------------------------------------------------------------*/
1439 createRegMask (eBBlock ** ebbs, int count)
1443 /* for all blocks */
1444 for (i = 0; i < count; i++)
1448 if (ebbs[i]->noPath &&
1449 (ebbs[i]->entryLabel != entryLabel &&
1450 ebbs[i]->entryLabel != returnLabel))
1453 /* for all instructions */
1454 for (ic = ebbs[i]->sch; ic; ic = ic->next)
1459 if (SKIP_IC2 (ic) || !ic->rlive)
1462 /* first mark the registers used in this
1464 ic->rUsed = regsUsedIniCode (ic);
1465 _G.funcrUsed = bitVectUnion (_G.funcrUsed, ic->rUsed);
1467 /* now create the register mask for those
1468 registers that are in use : this is a
1469 super set of ic->rUsed */
1470 ic->rMask = newBitVect (mcs51_nRegs + 1);
1472 /* for all live Ranges alive at this point */
1473 for (j = 1; j < ic->rlive->size; j++)
1478 /* if not alive then continue */
1479 if (!bitVectBitValue (ic->rlive, j))
1482 /* find the live range we are interested in */
1483 if (!(sym = hTabItemWithKey (liveRanges, j)))
1485 werror (E_INTERNAL_ERROR, __FILE__, __LINE__,
1486 "createRegMask cannot find live range");
1487 fprintf(stderr, "\tmissing live range: key=%d\n", j);
1491 /* if no register assigned to it */
1492 if (!sym->nRegs || sym->isspilt)
1495 /* for all the registers allocated to it */
1496 for (k = 0; k < sym->nRegs; k++)
1499 bitVectSetBit (ic->rMask, sym->regs[k]->rIdx);
1505 /*-----------------------------------------------------------------*/
1506 /* rematStr - returns the rematerialized string for a remat var */
1507 /*-----------------------------------------------------------------*/
1509 rematStr (symbol * sym)
1512 iCode *ic = sym->rematiCode;
1517 /* if plus or minus print the right hand side */
1518 if (ic->op == '+' || ic->op == '-')
1520 sprintf (s, "0x%04x %c ", (int) operandLitValue (IC_RIGHT (ic)),
1523 ic = OP_SYMBOL (IC_LEFT (ic))->rematiCode;
1527 /* cast then continue */
1528 if (IS_CAST_ICODE(ic)) {
1529 ic = OP_SYMBOL (IC_RIGHT (ic))->rematiCode;
1532 /* we reached the end */
1533 sprintf (s, "%s", OP_SYMBOL (IC_LEFT (ic))->rname);
1540 /*-----------------------------------------------------------------*/
1541 /* regTypeNum - computes the type & number of registers required */
1542 /*-----------------------------------------------------------------*/
1544 regTypeNum (eBBlock *ebbs)
1550 /* for each live range do */
1551 for (sym = hTabFirstItem (liveRanges, &k); sym;
1552 sym = hTabNextItem (liveRanges, &k))
1555 /* if used zero times then no registers needed */
1556 if ((sym->liveTo - sym->liveFrom) == 0)
1560 /* if the live range is a temporary */
1564 /* if the type is marked as a conditional */
1565 if (sym->regType == REG_CND)
1568 /* if used in return only then we don't
1570 if (sym->ruonly || sym->accuse)
1572 if (IS_AGGREGATE (sym->type) || sym->isptr)
1573 sym->type = aggrToPtr (sym->type, FALSE);
1578 /* if this symbol has only one usage and that is an assignment
1579 to a ruonly, we don't need registers */
1580 // if this symbol has only one def
1581 if (bitVectnBitsOn (sym->defs)==1) {
1582 printf ("sym: %s has only one usage", sym->name);
1584 if ((ic = hTabItemWithKey (iCodehTab, bitVectFirstBit (sym->defs)))) {
1586 printf (" for a call ");
1587 // if this is only assigned to a ruonly
1588 if ((ic = hTabItemWithKey (iCodehTab, bitVectFirstBit (sym->defs)))) {
1590 if (OP_SYMBOL(IC_RESULT(ic))->ruonly) {
1591 printf("regTypeNum: %s assigned to %s\n", \
1592 sym->name, OP_SYMBOL(IC_RESULT(ic))->name);
1601 /* if the symbol has only one definition &
1602 that definition is a get_pointer */
1603 if (bitVectnBitsOn (sym->defs) == 1 &&
1604 (ic = hTabItemWithKey (iCodehTab,
1605 bitVectFirstBit (sym->defs))) &&
1608 !IS_BITVAR (sym->etype))
1612 /* and that pointer is remat in data space */
1613 if (IS_SYMOP (IC_LEFT (ic)) &&
1614 OP_SYMBOL (IC_LEFT (ic))->remat &&
1615 !IS_CAST_ICODE(OP_SYMBOL (IC_LEFT (ic))->rematiCode) &&
1616 DCL_TYPE (aggrToPtr (operandType(IC_LEFT(ic)), FALSE)) == POINTER)
1618 /* create a psuedo symbol & force a spil */
1619 symbol *psym = newSymbol (rematStr (OP_SYMBOL (IC_LEFT (ic))), 1);
1620 psym->type = sym->type;
1621 psym->etype = sym->etype;
1622 strcpy (psym->rname, psym->name);
1624 sym->usl.spillLoc = psym;
1625 #if 0 // an alternative fix for bug #480076
1626 /* now this is a useless assignment to itself */
1627 remiCodeFromeBBlock (ebbs, ic);
1629 /* now this really is an assignment to itself, make it so;
1630 it will be optimized out later */
1632 ReplaceOpWithCheaperOp(&IC_RIGHT(ic), IC_RESULT(ic));
1638 /* if in data space or idata space then try to
1639 allocate pointer register */
1643 /* if not then we require registers */
1644 sym->nRegs = ((IS_AGGREGATE (sym->type) || sym->isptr) ?
1645 getSize (sym->type = aggrToPtr (sym->type, FALSE)) :
1646 getSize (sym->type));
1650 fprintf (stderr, "allocated more than 4 or 0 registers for type ");
1651 printTypeChain (sym->type, stderr);
1652 fprintf (stderr, "\n");
1655 /* determine the type of register required */
1656 if (sym->nRegs == 1 &&
1657 IS_PTR (sym->type) &&
1659 sym->regType = REG_PTR;
1661 sym->regType = REG_GPR;
1665 /* for the first run we don't provide */
1666 /* registers for true symbols we will */
1667 /* see how things go */
1673 /*-----------------------------------------------------------------*/
1674 /* freeAllRegs - mark all registers as free */
1675 /*-----------------------------------------------------------------*/
1681 for (i = 0; i < mcs51_nRegs; i++)
1682 regs8051[i].isFree = 1;
1685 /*-----------------------------------------------------------------*/
1686 /* deallocStackSpil - this will set the stack pointer back */
1687 /*-----------------------------------------------------------------*/
1689 DEFSETFUNC (deallocStackSpil)
1697 /*-----------------------------------------------------------------*/
1698 /* farSpacePackable - returns the packable icode for far variables */
1699 /*-----------------------------------------------------------------*/
1701 farSpacePackable (iCode * ic)
1705 /* go thru till we find a definition for the
1706 symbol on the right */
1707 for (dic = ic->prev; dic; dic = dic->prev)
1709 /* if the definition is a call then no */
1710 if ((dic->op == CALL || dic->op == PCALL) &&
1711 IC_RESULT (dic)->key == IC_RIGHT (ic)->key)
1716 /* if shift by unknown amount then not */
1717 if ((dic->op == LEFT_OP || dic->op == RIGHT_OP) &&
1718 IC_RESULT (dic)->key == IC_RIGHT (ic)->key)
1721 /* if pointer get and size > 1 */
1722 if (POINTER_GET (dic) &&
1723 getSize (aggrToPtr (operandType (IC_LEFT (dic)), FALSE)) > 1)
1726 if (POINTER_SET (dic) &&
1727 getSize (aggrToPtr (operandType (IC_RESULT (dic)), FALSE)) > 1)
1730 /* if any three is a true symbol in far space */
1731 if (IC_RESULT (dic) &&
1732 IS_TRUE_SYMOP (IC_RESULT (dic)) &&
1733 isOperandInFarSpace (IC_RESULT (dic)))
1736 if (IC_RIGHT (dic) &&
1737 IS_TRUE_SYMOP (IC_RIGHT (dic)) &&
1738 isOperandInFarSpace (IC_RIGHT (dic)) &&
1739 !isOperandEqual (IC_RIGHT (dic), IC_RESULT (ic)))
1742 if (IC_LEFT (dic) &&
1743 IS_TRUE_SYMOP (IC_LEFT (dic)) &&
1744 isOperandInFarSpace (IC_LEFT (dic)) &&
1745 !isOperandEqual (IC_LEFT (dic), IC_RESULT (ic)))
1748 if (isOperandEqual (IC_RIGHT (ic), IC_RESULT (dic)))
1750 if ((dic->op == LEFT_OP ||
1751 dic->op == RIGHT_OP ||
1753 IS_OP_LITERAL (IC_RIGHT (dic)))
1763 /*-----------------------------------------------------------------*/
1764 /* packRegsForAssign - register reduction for assignment */
1765 /*-----------------------------------------------------------------*/
1767 packRegsForAssign (iCode * ic, eBBlock * ebp)
1771 if (!IS_ITEMP (IC_RIGHT (ic)) ||
1772 OP_SYMBOL (IC_RIGHT (ic))->isind ||
1773 OP_LIVETO (IC_RIGHT (ic)) > ic->seq)
1779 /* if the true symbol is defined in far space or on stack
1780 then we should not since this will increase register pressure */
1781 if (isOperandInFarSpace(IC_RESULT(ic)) && !farSpacePackable(ic)) {
1785 /* find the definition of iTempNN scanning backwards if we find a
1786 a use of the true symbol in before we find the definition then
1788 for (dic = ic->prev; dic; dic = dic->prev)
1790 /* if there is a function call then don't pack it */
1791 if ((dic->op == CALL || dic->op == PCALL))
1800 if (IS_TRUE_SYMOP (IC_RESULT (dic)) &&
1801 IS_OP_VOLATILE (IC_RESULT (dic)))
1807 if (IS_SYMOP (IC_RESULT (dic)) &&
1808 IC_RESULT (dic)->key == IC_RIGHT (ic)->key)
1810 if (POINTER_SET (dic))
1816 if (IS_SYMOP (IC_RIGHT (dic)) &&
1817 (IC_RIGHT (dic)->key == IC_RESULT (ic)->key ||
1818 IC_RIGHT (dic)->key == IC_RIGHT (ic)->key))
1824 if (IS_SYMOP (IC_LEFT (dic)) &&
1825 (IC_LEFT (dic)->key == IC_RESULT (ic)->key ||
1826 IC_LEFT (dic)->key == IC_RIGHT (ic)->key))
1832 if (POINTER_SET (dic) &&
1833 IC_RESULT (dic)->key == IC_RESULT (ic)->key)
1841 return 0; /* did not find */
1843 /* if assignment then check that right is not a bit */
1844 if (ASSIGNMENT (dic) && !POINTER_SET (dic))
1846 sym_link *etype = operandType (IC_RIGHT (dic));
1847 if (IS_BITFIELD (etype))
1849 /* if result is a bit too then it's ok */
1850 etype = operandType (IC_RESULT (dic));
1851 if (!IS_BITFIELD (etype))
1855 /* if the result is on stack or iaccess then it must be
1856 the same atleast one of the operands */
1857 if (OP_SYMBOL (IC_RESULT (ic))->onStack ||
1858 OP_SYMBOL (IC_RESULT (ic))->iaccess)
1861 /* the operation has only one symbol
1862 operator then we can pack */
1863 if ((IC_LEFT (dic) && !IS_SYMOP (IC_LEFT (dic))) ||
1864 (IC_RIGHT (dic) && !IS_SYMOP (IC_RIGHT (dic))))
1867 if (!((IC_LEFT (dic) &&
1868 IC_RESULT (ic)->key == IC_LEFT (dic)->key) ||
1870 IC_RESULT (ic)->key == IC_RIGHT (dic)->key)))
1874 /* found the definition */
1875 /* replace the result with the result of */
1876 /* this assignment and remove this assignment */
1877 bitVectUnSetBit(OP_SYMBOL(IC_RESULT(dic))->defs,dic->key);
1878 ReplaceOpWithCheaperOp(&IC_RESULT (dic), IC_RESULT (ic));
1880 if (IS_ITEMP (IC_RESULT (dic)) && OP_SYMBOL (IC_RESULT (dic))->liveFrom > dic->seq)
1882 OP_SYMBOL (IC_RESULT (dic))->liveFrom = dic->seq;
1884 // TODO: and the otherway around?
1886 /* delete from liverange table also
1887 delete from all the points inbetween and the new
1889 for (sic = dic; sic != ic; sic = sic->next)
1891 bitVectUnSetBit (sic->rlive, IC_RESULT (ic)->key);
1892 if (IS_ITEMP (IC_RESULT (dic)))
1893 bitVectSetBit (sic->rlive, IC_RESULT (dic)->key);
1896 remiCodeFromeBBlock (ebp, ic);
1897 bitVectUnSetBit(OP_SYMBOL(IC_RESULT(ic))->defs,ic->key);
1898 hTabDeleteItem (&iCodehTab, ic->key, ic, DELETE_ITEM, NULL);
1899 OP_DEFS(IC_RESULT (dic))=bitVectSetBit (OP_DEFS (IC_RESULT (dic)), dic->key);
1903 /*------------------------------------------------------------------*/
1904 /* findAssignToSym : scanning backwards looks for first assig found */
1905 /*------------------------------------------------------------------*/
1907 findAssignToSym (operand * op, iCode * ic)
1911 /* This routine is used to find sequences like
1913 ...; (intervening ops don't use iTempAA or modify FOO)
1914 blah = blah + iTempAA;
1916 and eliminate the use of iTempAA, freeing up its register for
1921 for (dic = ic->prev; dic; dic = dic->prev)
1924 /* if definition by assignment */
1925 if (dic->op == '=' &&
1926 !POINTER_SET (dic) &&
1927 IC_RESULT (dic)->key == op->key
1928 /* && IS_TRUE_SYMOP(IC_RIGHT(dic)) */
1930 break; /* found where this temp was defined */
1932 /* if we find an usage then we cannot delete it */
1933 if (IC_LEFT (dic) && IC_LEFT (dic)->key == op->key)
1936 if (IC_RIGHT (dic) && IC_RIGHT (dic)->key == op->key)
1939 if (POINTER_SET (dic) && IC_RESULT (dic)->key == op->key)
1944 return NULL; /* didn't find any assignment to op */
1946 /* we are interested only if defined in far space */
1947 /* or in stack space in case of + & - */
1949 /* if assigned to a non-symbol then don't repack regs */
1950 if (!IS_SYMOP (IC_RIGHT (dic)))
1953 /* if the symbol is volatile then we should not */
1954 if (isOperandVolatile (IC_RIGHT (dic), TRUE))
1956 /* XXX TODO --- should we be passing FALSE to isOperandVolatile()?
1957 What does it mean for an iTemp to be volatile, anyway? Passing
1958 TRUE is more cautious but may prevent possible optimizations */
1960 /* if the symbol is in far space then we should not */
1961 if (isOperandInFarSpace (IC_RIGHT (dic)))
1964 /* for + & - operations make sure that
1965 if it is on the stack it is the same
1966 as one of the three operands */
1967 if ((ic->op == '+' || ic->op == '-') &&
1968 OP_SYMBOL (IC_RIGHT (dic))->onStack)
1971 if (IC_RESULT (ic)->key != IC_RIGHT (dic)->key &&
1972 IC_LEFT (ic)->key != IC_RIGHT (dic)->key &&
1973 IC_RIGHT (ic)->key != IC_RIGHT (dic)->key)
1977 /* now make sure that the right side of dic
1978 is not defined between ic & dic */
1981 iCode *sic = dic->next;
1983 for (; sic != ic; sic = sic->next)
1984 if (IC_RESULT (sic) &&
1985 IC_RESULT (sic)->key == IC_RIGHT (dic)->key)
1992 /*-----------------------------------------------------------------*/
1993 /* reassignAliasedSym - used by packRegsForSupport to replace */
1994 /* redundant iTemp with equivalent symbol */
1995 /*-----------------------------------------------------------------*/
1997 reassignAliasedSym (eBBlock *ebp, iCode *assignment, iCode *use, operand *op)
2000 unsigned oldSymKey, newSymKey;
2002 oldSymKey = op->key;
2003 newSymKey = IC_RIGHT(assignment)->key;
2005 /* only track live ranges of compiler-generated temporaries */
2006 if (!IS_ITEMP(IC_RIGHT(assignment)))
2009 /* update the live-value bitmaps */
2010 for (ic = assignment; ic != use; ic = ic->next) {
2011 bitVectUnSetBit (ic->rlive, oldSymKey);
2013 ic->rlive = bitVectSetBit (ic->rlive, newSymKey);
2016 /* update the sym of the used operand */
2017 OP_SYMBOL(op) = OP_SYMBOL(IC_RIGHT(assignment));
2018 op->key = OP_SYMBOL(op)->key;
2020 /* update the sym's liverange */
2021 if ( OP_LIVETO(op) < ic->seq )
2022 setToRange(op, ic->seq, FALSE);
2024 /* remove the assignment iCode now that its result is unused */
2025 remiCodeFromeBBlock (ebp, assignment);
2026 bitVectUnSetBit(OP_SYMBOL(IC_RESULT(assignment))->defs, assignment->key);
2027 hTabDeleteItem (&iCodehTab, assignment->key, assignment, DELETE_ITEM, NULL);
2031 /*-----------------------------------------------------------------*/
2032 /* packRegsForSupport :- reduce some registers for support calls */
2033 /*-----------------------------------------------------------------*/
2035 packRegsForSupport (iCode * ic, eBBlock * ebp)
2039 /* for the left & right operand :- look to see if the
2040 left was assigned a true symbol in far space in that
2041 case replace them */
2043 if (IS_ITEMP (IC_LEFT (ic)) &&
2044 OP_SYMBOL (IC_LEFT (ic))->liveTo <= ic->seq)
2046 dic = findAssignToSym (IC_LEFT (ic), ic);
2050 /* found it we need to remove it from the block */
2051 reassignAliasedSym (ebp, dic, ic, IC_LEFT(ic));
2056 /* do the same for the right operand */
2057 if (IS_ITEMP (IC_RIGHT (ic)) &&
2058 OP_SYMBOL (IC_RIGHT (ic))->liveTo <= ic->seq)
2060 iCode *dic = findAssignToSym (IC_RIGHT (ic), ic);
2064 /* if this is a subtraction & the result
2065 is a true symbol in far space then don't pack */
2066 if (ic->op == '-' && IS_TRUE_SYMOP (IC_RESULT (dic)))
2068 sym_link *etype = getSpec (operandType (IC_RESULT (dic)));
2069 if (IN_FARSPACE (SPEC_OCLS (etype)))
2072 /* found it we need to remove it from the
2074 reassignAliasedSym (ebp, dic, ic, IC_RIGHT(ic));
2083 #define IS_OP_RUONLY(x) (x && IS_SYMOP(x) && OP_SYMBOL(x)->ruonly)
2086 /*-----------------------------------------------------------------*/
2087 /* packRegsForOneuse : - will reduce some registers for single Use */
2088 /*-----------------------------------------------------------------*/
2090 packRegsForOneuse (iCode * ic, operand * op, eBBlock * ebp)
2095 /* if returning a literal then do nothing */
2099 /* only upto 2 bytes since we cannot predict
2100 the usage of b, & acc */
2101 if (getSize (operandType (op)) > (fReturnSizeMCS51 - 2))
2104 if (ic->op != RETURN &&
2106 !POINTER_SET (ic) &&
2110 if (ic->op == SEND && ic->argreg != 1) return NULL;
2112 /* this routine will mark the a symbol as used in one
2113 instruction use only && if the defintion is local
2114 (ie. within the basic block) && has only one definition &&
2115 that definiion is either a return value from a
2116 function or does not contain any variables in
2118 uses = bitVectCopy (OP_USES (op));
2119 bitVectUnSetBit (uses, ic->key); /* take away this iCode */
2120 if (!bitVectIsZero (uses)) /* has other uses */
2123 /* if it has only one defintion */
2124 if (bitVectnBitsOn (OP_DEFS (op)) > 1)
2125 return NULL; /* has more than one definition */
2127 /* get that definition */
2129 hTabItemWithKey (iCodehTab,
2130 bitVectFirstBit (OP_DEFS (op)))))
2133 /* if that only usage is a cast */
2134 if (dic->op == CAST) {
2135 /* to a bigger type */
2136 if (getSize(OP_SYM_TYPE(IC_RESULT(dic))) >
2137 getSize(OP_SYM_TYPE(IC_RIGHT(dic)))) {
2138 /* than we can not, since we cannot predict the usage of b & acc */
2143 /* found the definition now check if it is local */
2144 if (dic->seq < ebp->fSeq ||
2145 dic->seq > ebp->lSeq)
2146 return NULL; /* non-local */
2148 /* now check if it is the return from
2150 if (dic->op == CALL || dic->op == PCALL)
2152 if (ic->op != SEND && ic->op != RETURN &&
2153 !POINTER_SET(ic) && !POINTER_GET(ic))
2155 OP_SYMBOL (op)->ruonly = 1;
2162 /* otherwise check that the definition does
2163 not contain any symbols in far space */
2164 if (isOperandInFarSpace (IC_LEFT (dic)) ||
2165 isOperandInFarSpace (IC_RIGHT (dic)) ||
2166 IS_OP_RUONLY (IC_LEFT (ic)) ||
2167 IS_OP_RUONLY (IC_RIGHT (ic)))
2172 /* if pointer set then make sure the pointer
2174 if (POINTER_SET (dic) &&
2175 !IS_DATA_PTR (aggrToPtr (operandType (IC_RESULT (dic)), FALSE)))
2178 if (POINTER_GET (dic) &&
2179 !IS_DATA_PTR (aggrToPtr (operandType (IC_LEFT (dic)), FALSE)))
2184 /* also make sure the intervenening instructions
2185 don't have any thing in far space */
2186 for (dic = dic->next; dic && dic != ic && sic != ic; dic = dic->next)
2189 /* if there is an intervening function call then no */
2190 if (dic->op == CALL || dic->op == PCALL)
2192 /* if pointer set then make sure the pointer
2194 if (POINTER_SET (dic) &&
2195 !IS_DATA_PTR (aggrToPtr (operandType (IC_RESULT (dic)), FALSE)))
2198 if (POINTER_GET (dic) &&
2199 !IS_DATA_PTR (aggrToPtr (operandType (IC_LEFT (dic)), FALSE)))
2202 /* if address of & the result is remat the okay */
2203 if (dic->op == ADDRESS_OF &&
2204 OP_SYMBOL (IC_RESULT (dic))->remat)
2207 /* if operand has size of three or more & this
2208 operation is a '*','/' or '%' then 'b' may
2210 if ((dic->op == '%' || dic->op == '/' || dic->op == '*') &&
2211 getSize (operandType (op)) >= 3)
2214 /* if left or right or result is in far space */
2215 if (isOperandInFarSpace (IC_LEFT (dic)) ||
2216 isOperandInFarSpace (IC_RIGHT (dic)) ||
2217 isOperandInFarSpace (IC_RESULT (dic)) ||
2218 IS_OP_RUONLY (IC_LEFT (dic)) ||
2219 IS_OP_RUONLY (IC_RIGHT (dic)) ||
2220 IS_OP_RUONLY (IC_RESULT (dic)))
2224 /* if left or right or result is on stack */
2225 if (isOperandOnStack(IC_LEFT(dic)) ||
2226 isOperandOnStack(IC_RIGHT(dic)) ||
2227 isOperandOnStack(IC_RESULT(dic))) {
2232 OP_SYMBOL (op)->ruonly = 1;
2236 /*-----------------------------------------------------------------*/
2237 /* isBitwiseOptimizable - requirements of JEAN LOUIS VERN */
2238 /*-----------------------------------------------------------------*/
2240 isBitwiseOptimizable (iCode * ic)
2242 sym_link *ltype = getSpec (operandType (IC_LEFT (ic)));
2243 sym_link *rtype = getSpec (operandType (IC_RIGHT (ic)));
2245 /* bitwise operations are considered optimizable
2246 under the following conditions (Jean-Louis VERN)
2258 if (IS_LITERAL(rtype) ||
2259 (IS_BITVAR (ltype) && IN_BITSPACE (SPEC_OCLS (ltype))))
2265 /*-----------------------------------------------------------------*/
2266 /* isCommutativeOp - tests whether this op cares what order its */
2267 /* operands are in */
2268 /*-----------------------------------------------------------------*/
2269 bool isCommutativeOp(unsigned int op)
2271 if (op == '+' || op == '*' || op == EQ_OP ||
2272 op == '^' || op == '|' || op == BITWISEAND)
2278 /*-----------------------------------------------------------------*/
2279 /* operandUsesAcc - determines whether the code generated for this */
2280 /* operand will have to use the accumulator */
2281 /*-----------------------------------------------------------------*/
2282 bool operandUsesAcc(operand *op)
2288 symbol *sym = OP_SYMBOL(op);
2292 return TRUE; /* duh! */
2294 if (IN_STACK(sym->etype) || sym->onStack ||
2295 (SPIL_LOC(op) && SPIL_LOC(op)->onStack))
2296 return TRUE; /* acc is used to calc stack offset */
2301 sym = SPIL_LOC(op); /* if spilled, look at spill location */
2303 return FALSE; /* more checks? */
2307 symspace = SPEC_OCLS(sym->etype);
2309 if (sym->iaccess && symspace->paged)
2310 return TRUE; /* must fetch paged indirect sym via accumulator */
2312 if (IN_BITSPACE(symspace))
2313 return TRUE; /* fetching bit vars uses the accumulator */
2315 if (IN_FARSPACE(symspace) || IN_CODESPACE(symspace))
2316 return TRUE; /* fetched via accumulator and dptr */
2322 /*-----------------------------------------------------------------*/
2323 /* packRegsForAccUse - pack registers for acc use */
2324 /*-----------------------------------------------------------------*/
2326 packRegsForAccUse (iCode * ic)
2330 /* if this is an aggregate, e.g. a one byte char array */
2331 if (IS_AGGREGATE(operandType(IC_RESULT(ic)))) {
2335 /* if we are calling a reentrant function that has stack parameters */
2336 if (ic->op == CALL &&
2337 IFFUNC_ISREENT(operandType(IC_LEFT(ic))) &&
2338 FUNC_HASSTACKPARM(operandType(IC_LEFT(ic))))
2341 if (ic->op == PCALL &&
2342 IFFUNC_ISREENT(operandType(IC_LEFT(ic))->next) &&
2343 FUNC_HASSTACKPARM(operandType(IC_LEFT(ic))->next))
2346 /* if + or - then it has to be one byte result */
2347 if ((ic->op == '+' || ic->op == '-')
2348 && getSize (operandType (IC_RESULT (ic))) > 1)
2351 /* if shift operation make sure right side is not a literal */
2352 if (ic->op == RIGHT_OP &&
2353 (isOperandLiteral (IC_RIGHT (ic)) ||
2354 getSize (operandType (IC_RESULT (ic))) > 1))
2357 if (ic->op == LEFT_OP &&
2358 (isOperandLiteral (IC_RIGHT (ic)) ||
2359 getSize (operandType (IC_RESULT (ic))) > 1))
2362 if (IS_BITWISE_OP (ic) &&
2363 getSize (operandType (IC_RESULT (ic))) > 1)
2367 /* has only one definition */
2368 if (bitVectnBitsOn (OP_DEFS (IC_RESULT (ic))) > 1)
2371 /* has only one use */
2372 if (bitVectnBitsOn (OP_USES (IC_RESULT (ic))) > 1)
2375 /* and the usage immediately follows this iCode */
2376 if (!(uic = hTabItemWithKey (iCodehTab,
2377 bitVectFirstBit (OP_USES (IC_RESULT (ic))))))
2380 if (ic->next != uic)
2383 /* if it is a conditional branch then we definitely can */
2387 if (uic->op == JUMPTABLE)
2390 if (POINTER_SET (uic) &&
2391 getSize (aggrToPtr (operandType (IC_RESULT (uic)), FALSE)) > 1)
2394 /* if the usage is not is an assignment
2395 or an arithmetic / bitwise / shift operation then not */
2396 if (uic->op != '=' &&
2397 !IS_ARITHMETIC_OP (uic) &&
2398 !IS_BITWISE_OP (uic) &&
2399 uic->op != LEFT_OP &&
2400 uic->op != RIGHT_OP)
2403 /* if used in ^ operation then make sure right is not a
2404 literal (WIML: Why is this?) */
2405 if (uic->op == '^' && isOperandLiteral (IC_RIGHT (uic)))
2408 /* if shift operation make sure right side is not a literal */
2409 /* WIML: Why is this? */
2410 if (uic->op == RIGHT_OP &&
2411 (isOperandLiteral (IC_RIGHT (uic)) ||
2412 getSize (operandType (IC_RESULT (uic))) > 1))
2414 if (uic->op == LEFT_OP &&
2415 (isOperandLiteral (IC_RIGHT (uic)) ||
2416 getSize (operandType (IC_RESULT (uic))) > 1))
2419 /* make sure that the result of this icode is not on the
2420 stack, since acc is used to compute stack offset */
2422 if (IS_TRUE_SYMOP (IC_RESULT (uic)) &&
2423 OP_SYMBOL (IC_RESULT (uic))->onStack)
2426 if (isOperandOnStack(IC_RESULT(uic)))
2430 /* if the usage has only one operand then we can */
2431 if (IC_LEFT (uic) == NULL ||
2432 IC_RIGHT (uic) == NULL)
2435 /* if the other operand uses the accumulator then we cannot */
2436 if ( (IC_LEFT(uic)->key == IC_RESULT(ic)->key &&
2437 operandUsesAcc(IC_RIGHT(uic))) ||
2438 (IC_RIGHT(uic)->key == IC_RESULT(ic)->key &&
2439 operandUsesAcc(IC_LEFT(uic))) )
2442 /* make sure this is on the left side if not commutative */
2443 /* except for '-', which has been written to be able to
2444 handle reversed operands */
2445 if (!(isCommutativeOp(ic->op) || ic->op == '-') &&
2446 IC_LEFT (uic)->key != IC_RESULT (ic)->key)
2450 // this is too dangerous and need further restrictions
2453 /* if one of them is a literal then we can */
2454 if ((IC_LEFT (uic) && IS_OP_LITERAL (IC_LEFT (uic))) ||
2455 (IC_RIGHT (uic) && IS_OP_LITERAL (IC_RIGHT (uic))))
2457 OP_SYMBOL (IC_RESULT (ic))->accuse = 1;
2463 OP_SYMBOL (IC_RESULT (ic))->accuse = 1;
2467 /*-----------------------------------------------------------------*/
2468 /* packForPush - hueristics to reduce iCode for pushing */
2469 /*-----------------------------------------------------------------*/
2471 packForPush (iCode * ic, eBBlock ** ebpp, int blockno)
2475 struct eBBlock * ebp=ebpp[blockno];
2477 if (ic->op != IPUSH || !IS_ITEMP (IC_LEFT (ic)))
2480 /* must have only definition & one usage */
2481 if (bitVectnBitsOn (OP_DEFS (IC_LEFT (ic))) != 1 ||
2482 bitVectnBitsOn (OP_USES (IC_LEFT (ic))) != 1)
2485 /* find the definition */
2486 if (!(dic = hTabItemWithKey (iCodehTab,
2487 bitVectFirstBit (OP_DEFS (IC_LEFT (ic))))))
2490 if (dic->op != '=' || POINTER_SET (dic))
2493 if (dic->seq < ebp->fSeq) { // Evelyn did this
2495 for (i=0; i<blockno; i++) {
2496 if (dic->seq >= ebpp[i]->fSeq && dic->seq <= ebpp[i]->lSeq) {
2501 wassert (i!=blockno); // no way to recover from here
2504 if (IS_SYMOP(IC_RIGHT(dic))) {
2505 /* make sure the right side does not have any definitions
2507 dbv = OP_DEFS(IC_RIGHT(dic));
2508 for (lic = ic; lic && lic != dic ; lic = lic->prev) {
2509 if (bitVectBitValue(dbv,lic->key))
2512 /* make sure they have the same type */
2513 if (IS_SPEC(operandType(IC_LEFT(ic))))
2515 sym_link *itype=operandType(IC_LEFT(ic));
2516 sym_link *ditype=operandType(IC_RIGHT(dic));
2518 if (SPEC_USIGN(itype)!=SPEC_USIGN(ditype) ||
2519 SPEC_LONG(itype)!=SPEC_LONG(ditype))
2522 /* extend the live range of replaced operand if needed */
2523 if (OP_SYMBOL(IC_RIGHT(dic))->liveTo < ic->seq) {
2524 OP_SYMBOL(IC_RIGHT(dic))->liveTo = ic->seq;
2526 bitVectUnSetBit(OP_SYMBOL(IC_RESULT(dic))->defs,dic->key);
2529 /* we now we know that it has one & only one def & use
2530 and the that the definition is an assignment */
2531 ReplaceOpWithCheaperOp(&IC_LEFT (ic), IC_RIGHT (dic));
2532 remiCodeFromeBBlock (ebp, dic);
2533 hTabDeleteItem (&iCodehTab, dic->key, dic, DELETE_ITEM, NULL);
2536 /*-----------------------------------------------------------------*/
2537 /* packRegisters - does some transformations to reduce register */
2539 /*-----------------------------------------------------------------*/
2541 packRegisters (eBBlock ** ebpp, int blockno)
2545 eBBlock *ebp=ebpp[blockno];
2552 /* look for assignments of the form */
2553 /* iTempNN = TRueSym (someoperation) SomeOperand */
2555 /* TrueSym := iTempNN:1 */
2556 for (ic = ebp->sch; ic; ic = ic->next)
2558 /* find assignment of the form TrueSym := iTempNN:1 */
2559 if (ic->op == '=' && !POINTER_SET (ic))
2560 change += packRegsForAssign (ic, ebp);
2567 for (ic = ebp->sch; ic; ic = ic->next)
2569 /* if this is an itemp & result of an address of a true sym
2570 then mark this as rematerialisable */
2571 if (ic->op == ADDRESS_OF &&
2572 IS_ITEMP (IC_RESULT (ic)) &&
2573 IS_TRUE_SYMOP (IC_LEFT (ic)) &&
2574 bitVectnBitsOn (OP_DEFS (IC_RESULT (ic))) == 1 &&
2575 !OP_SYMBOL (IC_LEFT (ic))->onStack)
2578 OP_SYMBOL (IC_RESULT (ic))->remat = 1;
2579 OP_SYMBOL (IC_RESULT (ic))->rematiCode = ic;
2580 OP_SYMBOL (IC_RESULT (ic))->usl.spillLoc = NULL;
2584 /* if straight assignment then carry remat flag if
2585 this is the only definition */
2586 if (ic->op == '=' &&
2587 !POINTER_SET (ic) &&
2588 IS_SYMOP (IC_RIGHT (ic)) &&
2589 OP_SYMBOL (IC_RIGHT (ic))->remat &&
2590 !IS_CAST_ICODE(OP_SYMBOL (IC_RIGHT (ic))->rematiCode) &&
2591 bitVectnBitsOn (OP_SYMBOL (IC_RESULT (ic))->defs) <= 1)
2594 OP_SYMBOL (IC_RESULT (ic))->remat =
2595 OP_SYMBOL (IC_RIGHT (ic))->remat;
2596 OP_SYMBOL (IC_RESULT (ic))->rematiCode =
2597 OP_SYMBOL (IC_RIGHT (ic))->rematiCode;
2600 /* if cast to a generic pointer & the pointer being
2601 cast is remat, then we can remat this cast as well */
2602 if (ic->op == CAST &&
2603 IS_SYMOP(IC_RIGHT(ic)) &&
2604 OP_SYMBOL(IC_RIGHT(ic))->remat ) {
2605 sym_link *to_type = operandType(IC_LEFT(ic));
2606 sym_link *from_type = operandType(IC_RIGHT(ic));
2607 if (IS_GENPTR(to_type) && IS_PTR(from_type)) {
2608 OP_SYMBOL (IC_RESULT (ic))->remat = 1;
2609 OP_SYMBOL (IC_RESULT (ic))->rematiCode = ic;
2610 OP_SYMBOL (IC_RESULT (ic))->usl.spillLoc = NULL;
2614 /* if this is a +/- operation with a rematerizable
2615 then mark this as rematerializable as well */
2616 if ((ic->op == '+' || ic->op == '-') &&
2617 (IS_SYMOP (IC_LEFT (ic)) &&
2618 IS_ITEMP (IC_RESULT (ic)) &&
2619 IS_OP_LITERAL (IC_RIGHT (ic))) &&
2620 OP_SYMBOL (IC_LEFT (ic))->remat &&
2621 (!IS_SYMOP (IC_RIGHT (ic)) || !IS_CAST_ICODE(OP_SYMBOL (IC_RIGHT (ic))->rematiCode)) &&
2622 bitVectnBitsOn (OP_DEFS (IC_RESULT (ic))) == 1)
2624 OP_SYMBOL (IC_RESULT (ic))->remat = 1;
2625 OP_SYMBOL (IC_RESULT (ic))->rematiCode = ic;
2626 OP_SYMBOL (IC_RESULT (ic))->usl.spillLoc = NULL;
2629 /* mark the pointer usages */
2630 if (POINTER_SET (ic))
2631 OP_SYMBOL (IC_RESULT (ic))->uptr = 1;
2633 if (POINTER_GET (ic) &&
2634 IS_SYMOP(IC_LEFT (ic)))
2635 OP_SYMBOL (IC_LEFT (ic))->uptr = 1;
2639 /* if we are using a symbol on the stack
2640 then we should say mcs51_ptrRegReq */
2641 if (ic->op == IFX && IS_SYMOP (IC_COND (ic)))
2642 mcs51_ptrRegReq += ((OP_SYMBOL (IC_COND (ic))->onStack ||
2643 OP_SYMBOL (IC_COND (ic))->iaccess) ? 1 : 0);
2644 else if (ic->op == JUMPTABLE && IS_SYMOP (IC_JTCOND (ic)))
2645 mcs51_ptrRegReq += ((OP_SYMBOL (IC_JTCOND (ic))->onStack ||
2646 OP_SYMBOL (IC_JTCOND (ic))->iaccess) ? 1 : 0);
2649 if (IS_SYMOP (IC_LEFT (ic)))
2650 mcs51_ptrRegReq += ((OP_SYMBOL (IC_LEFT (ic))->onStack ||
2651 OP_SYMBOL (IC_LEFT (ic))->iaccess) ? 1 : 0);
2652 if (IS_SYMOP (IC_RIGHT (ic)))
2653 mcs51_ptrRegReq += ((OP_SYMBOL (IC_RIGHT (ic))->onStack ||
2654 OP_SYMBOL (IC_RIGHT (ic))->iaccess) ? 1 : 0);
2655 if (IS_SYMOP (IC_RESULT (ic)))
2656 mcs51_ptrRegReq += ((OP_SYMBOL (IC_RESULT (ic))->onStack ||
2657 OP_SYMBOL (IC_RESULT (ic))->iaccess) ? 1 : 0);
2661 /* if the condition of an if instruction
2662 is defined in the previous instruction and
2663 this is the only usage then
2664 mark the itemp as a conditional */
2665 if ((IS_CONDITIONAL (ic) ||
2666 (IS_BITWISE_OP(ic) && isBitwiseOptimizable (ic))) &&
2667 ic->next && ic->next->op == IFX &&
2668 bitVectnBitsOn (OP_USES(IC_RESULT(ic)))==1 &&
2669 isOperandEqual (IC_RESULT (ic), IC_COND (ic->next)) &&
2670 OP_SYMBOL (IC_RESULT (ic))->liveTo <= ic->next->seq)
2672 OP_SYMBOL (IC_RESULT (ic))->regType = REG_CND;
2676 /* reduce for support function calls */
2677 if (ic->supportRtn || ic->op == '+' || ic->op == '-')
2678 packRegsForSupport (ic, ebp);
2680 /* some cases the redundant moves can
2681 can be eliminated for return statements */
2682 if ((ic->op == RETURN || (ic->op == SEND && ic->argreg == 1)) &&
2683 !isOperandInFarSpace (IC_LEFT (ic)) &&
2684 options.model == MODEL_SMALL) {
2685 packRegsForOneuse (ic, IC_LEFT (ic), ebp);
2688 /* if pointer set & left has a size more than
2689 one and right is not in far space */
2690 if (POINTER_SET (ic) &&
2691 !isOperandInFarSpace (IC_RIGHT (ic)) &&
2692 !OP_SYMBOL (IC_RESULT (ic))->remat &&
2693 !IS_OP_RUONLY (IC_RIGHT (ic)) &&
2694 getSize (aggrToPtr (operandType (IC_RESULT (ic)), FALSE)) > 1)
2695 packRegsForOneuse (ic, IC_RESULT (ic), ebp);
2697 /* if pointer get */
2698 if (POINTER_GET (ic) &&
2699 IS_SYMOP (IC_LEFT (ic)) &&
2700 !isOperandInFarSpace (IC_RESULT (ic)) &&
2701 !OP_SYMBOL (IC_LEFT (ic))->remat &&
2702 !IS_OP_RUONLY (IC_RESULT (ic)) &&
2703 getSize (aggrToPtr (operandType (IC_LEFT (ic)), FALSE)) > 1)
2704 packRegsForOneuse (ic, IC_LEFT (ic), ebp);
2707 /* if this is cast for intergral promotion then
2708 check if only use of the definition of the
2709 operand being casted/ if yes then replace
2710 the result of that arithmetic operation with
2711 this result and get rid of the cast */
2714 sym_link *fromType = operandType (IC_RIGHT (ic));
2715 sym_link *toType = operandType (IC_LEFT (ic));
2717 if (IS_INTEGRAL (fromType) && IS_INTEGRAL (toType) &&
2718 getSize (fromType) != getSize (toType) &&
2719 SPEC_USIGN (fromType) == SPEC_USIGN (toType))
2722 iCode *dic = packRegsForOneuse (ic, IC_RIGHT (ic), ebp);
2725 if (IS_ARITHMETIC_OP (dic))
2727 bitVectUnSetBit(OP_SYMBOL(IC_RESULT(dic))->defs,dic->key);
2728 ReplaceOpWithCheaperOp(&IC_RESULT (dic), IC_RESULT (ic));
2729 remiCodeFromeBBlock (ebp, ic);
2730 bitVectUnSetBit(OP_SYMBOL(IC_RESULT(ic))->defs,ic->key);
2731 hTabDeleteItem (&iCodehTab, ic->key, ic, DELETE_ITEM, NULL);
2732 OP_DEFS(IC_RESULT (dic))=bitVectSetBit (OP_DEFS (IC_RESULT (dic)), dic->key);
2736 OP_SYMBOL (IC_RIGHT (ic))->ruonly = 0;
2742 /* if the type from and type to are the same
2743 then if this is the only use then packit */
2744 if (compareType (operandType (IC_RIGHT (ic)),
2745 operandType (IC_LEFT (ic))) == 1)
2747 iCode *dic = packRegsForOneuse (ic, IC_RIGHT (ic), ebp);
2750 bitVectUnSetBit(OP_SYMBOL(IC_RESULT(dic))->defs,dic->key);
2751 ReplaceOpWithCheaperOp(&IC_RESULT (dic), IC_RESULT (ic));
2752 remiCodeFromeBBlock (ebp, ic);
2753 bitVectUnSetBit(OP_SYMBOL(IC_RESULT(ic))->defs,ic->key);
2754 hTabDeleteItem (&iCodehTab, ic->key, ic, DELETE_ITEM, NULL);
2755 OP_DEFS(IC_RESULT (dic))=bitVectSetBit (OP_DEFS (IC_RESULT (dic)), dic->key);
2763 iTempNN := (some variable in farspace) V1
2768 if (ic->op == IPUSH)
2770 packForPush (ic, ebpp, blockno);
2774 /* pack registers for accumulator use, when the
2775 result of an arithmetic or bit wise operation
2776 has only one use, that use is immediately following
2777 the defintion and the using iCode has only one
2778 operand or has two operands but one is literal &
2779 the result of that operation is not on stack then
2780 we can leave the result of this operation in acc:b
2782 if ((IS_ARITHMETIC_OP (ic)
2783 || IS_CONDITIONAL(ic)
2784 || IS_BITWISE_OP (ic)
2785 || ic->op == LEFT_OP || ic->op == RIGHT_OP || ic->op == CALL
2786 || (ic->op == ADDRESS_OF && isOperandOnStack (IC_LEFT (ic)))
2788 IS_ITEMP (IC_RESULT (ic)) &&
2789 getSize (operandType (IC_RESULT (ic))) <= 2)
2791 packRegsForAccUse (ic);
2795 /*-----------------------------------------------------------------*/
2796 /* assignRegisters - assigns registers to each live range as need */
2797 /*-----------------------------------------------------------------*/
2799 mcs51_assignRegisters (eBBlock ** ebbs, int count)
2804 setToNull ((void *) &_G.funcrUsed);
2805 setToNull ((void *) &_G.regAssigned);
2806 setToNull ((void *) &_G.totRegAssigned);
2807 mcs51_ptrRegReq = _G.stackExtend = _G.dataExtend = 0;
2810 /* change assignments this will remove some
2811 live ranges reducing some register pressure */
2812 for (i = 0; i < count; i++)
2813 packRegisters (ebbs, i);
2815 if (options.dump_pack)
2816 dumpEbbsToFileExt (DUMP_PACK, ebbs, count);
2818 /* first determine for each live range the number of
2819 registers & the type of registers required for each */
2822 /* and serially allocate registers */
2823 serialRegAssign (ebbs, count);
2826 //setToNull ((void *) &_G.regAssigned);
2827 //setToNull ((void *) &_G.totRegAssigned);
2830 /* if stack was extended then tell the user */
2833 /* werror(W_TOOMANY_SPILS,"stack", */
2834 /* _G.stackExtend,currFunc->name,""); */
2840 /* werror(W_TOOMANY_SPILS,"data space", */
2841 /* _G.dataExtend,currFunc->name,""); */
2845 /* after that create the register mask
2846 for each of the instruction */
2847 createRegMask (ebbs, count);
2849 /* redo that offsets for stacked automatic variables */
2851 redoStackOffsets ();
2854 if (options.dump_rassgn)
2856 dumpEbbsToFileExt (DUMP_RASSGN, ebbs, count);
2857 dumpLiveRanges (DUMP_LRANGE, liveRanges);
2860 /* do the overlaysegment stuff SDCCmem.c */
2861 doOverlays (ebbs, count);
2863 /* now get back the chain */
2864 ic = iCodeLabelOptimize (iCodeFromeBBlock (ebbs, count));
2868 /* free up any _G.stackSpil locations allocated */
2869 applyToSet (_G.stackSpil, deallocStackSpil);
2871 setToNull ((void **) &_G.stackSpil);
2872 setToNull ((void **) &_G.spiltSet);
2873 /* mark all registers as free */