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);
1577 /* if the symbol has only one definition &
1578 that definition is a get_pointer */
1579 if (bitVectnBitsOn (sym->defs) == 1 &&
1580 (ic = hTabItemWithKey (iCodehTab,
1581 bitVectFirstBit (sym->defs))) &&
1584 !IS_BITVAR (sym->etype))
1588 /* and that pointer is remat in data space */
1589 if (IS_SYMOP (IC_LEFT (ic)) &&
1590 OP_SYMBOL (IC_LEFT (ic))->remat &&
1591 !IS_CAST_ICODE(OP_SYMBOL (IC_LEFT (ic))->rematiCode) &&
1592 DCL_TYPE (aggrToPtr (operandType(IC_LEFT(ic)), FALSE)) == POINTER)
1594 /* create a psuedo symbol & force a spil */
1595 symbol *psym = newSymbol (rematStr (OP_SYMBOL (IC_LEFT (ic))), 1);
1596 psym->type = sym->type;
1597 psym->etype = sym->etype;
1598 strcpy (psym->rname, psym->name);
1600 sym->usl.spillLoc = psym;
1601 #if 0 // an alternative fix for bug #480076
1602 /* now this is a useless assignment to itself */
1603 remiCodeFromeBBlock (ebbs, ic);
1605 /* now this really is an assignment to itself, make it so;
1606 it will be optimized out later */
1608 ReplaceOpWithCheaperOp(&IC_RIGHT(ic), IC_RESULT(ic));
1614 /* if in data space or idata space then try to
1615 allocate pointer register */
1619 /* if not then we require registers */
1620 sym->nRegs = ((IS_AGGREGATE (sym->type) || sym->isptr) ?
1621 getSize (sym->type = aggrToPtr (sym->type, FALSE)) :
1622 getSize (sym->type));
1626 fprintf (stderr, "allocated more than 4 or 0 registers for type ");
1627 printTypeChain (sym->type, stderr);
1628 fprintf (stderr, "\n");
1631 /* determine the type of register required */
1632 if (sym->nRegs == 1 &&
1633 IS_PTR (sym->type) &&
1635 sym->regType = REG_PTR;
1637 sym->regType = REG_GPR;
1641 /* for the first run we don't provide */
1642 /* registers for true symbols we will */
1643 /* see how things go */
1649 /*-----------------------------------------------------------------*/
1650 /* freeAllRegs - mark all registers as free */
1651 /*-----------------------------------------------------------------*/
1657 for (i = 0; i < mcs51_nRegs; i++)
1658 regs8051[i].isFree = 1;
1661 /*-----------------------------------------------------------------*/
1662 /* deallocStackSpil - this will set the stack pointer back */
1663 /*-----------------------------------------------------------------*/
1665 DEFSETFUNC (deallocStackSpil)
1673 /*-----------------------------------------------------------------*/
1674 /* farSpacePackable - returns the packable icode for far variables */
1675 /*-----------------------------------------------------------------*/
1677 farSpacePackable (iCode * ic)
1681 /* go thru till we find a definition for the
1682 symbol on the right */
1683 for (dic = ic->prev; dic; dic = dic->prev)
1685 /* if the definition is a call then no */
1686 if ((dic->op == CALL || dic->op == PCALL) &&
1687 IC_RESULT (dic)->key == IC_RIGHT (ic)->key)
1692 /* if shift by unknown amount then not */
1693 if ((dic->op == LEFT_OP || dic->op == RIGHT_OP) &&
1694 IC_RESULT (dic)->key == IC_RIGHT (ic)->key)
1697 /* if pointer get and size > 1 */
1698 if (POINTER_GET (dic) &&
1699 getSize (aggrToPtr (operandType (IC_LEFT (dic)), FALSE)) > 1)
1702 if (POINTER_SET (dic) &&
1703 getSize (aggrToPtr (operandType (IC_RESULT (dic)), FALSE)) > 1)
1706 /* if any three is a true symbol in far space */
1707 if (IC_RESULT (dic) &&
1708 IS_TRUE_SYMOP (IC_RESULT (dic)) &&
1709 isOperandInFarSpace (IC_RESULT (dic)))
1712 if (IC_RIGHT (dic) &&
1713 IS_TRUE_SYMOP (IC_RIGHT (dic)) &&
1714 isOperandInFarSpace (IC_RIGHT (dic)) &&
1715 !isOperandEqual (IC_RIGHT (dic), IC_RESULT (ic)))
1718 if (IC_LEFT (dic) &&
1719 IS_TRUE_SYMOP (IC_LEFT (dic)) &&
1720 isOperandInFarSpace (IC_LEFT (dic)) &&
1721 !isOperandEqual (IC_LEFT (dic), IC_RESULT (ic)))
1724 if (isOperandEqual (IC_RIGHT (ic), IC_RESULT (dic)))
1726 if ((dic->op == LEFT_OP ||
1727 dic->op == RIGHT_OP ||
1729 IS_OP_LITERAL (IC_RIGHT (dic)))
1739 /*-----------------------------------------------------------------*/
1740 /* packRegsForAssign - register reduction for assignment */
1741 /*-----------------------------------------------------------------*/
1743 packRegsForAssign (iCode * ic, eBBlock * ebp)
1747 if (!IS_ITEMP (IC_RIGHT (ic)) ||
1748 OP_SYMBOL (IC_RIGHT (ic))->isind ||
1749 OP_LIVETO (IC_RIGHT (ic)) > ic->seq)
1755 /* if the true symbol is defined in far space or on stack
1756 then we should not since this will increase register pressure */
1757 if (isOperandInFarSpace(IC_RESULT(ic)) && !farSpacePackable(ic)) {
1761 /* find the definition of iTempNN scanning backwards if we find a
1762 a use of the true symbol in before we find the definition then
1764 for (dic = ic->prev; dic; dic = dic->prev)
1766 /* if there is a function call then don't pack it */
1767 if ((dic->op == CALL || dic->op == PCALL))
1776 if (IS_TRUE_SYMOP (IC_RESULT (dic)) &&
1777 IS_OP_VOLATILE (IC_RESULT (dic)))
1783 if (IS_SYMOP (IC_RESULT (dic)) &&
1784 IC_RESULT (dic)->key == IC_RIGHT (ic)->key)
1786 if (POINTER_SET (dic))
1792 if (IS_SYMOP (IC_RIGHT (dic)) &&
1793 (IC_RIGHT (dic)->key == IC_RESULT (ic)->key ||
1794 IC_RIGHT (dic)->key == IC_RIGHT (ic)->key))
1800 if (IS_SYMOP (IC_LEFT (dic)) &&
1801 (IC_LEFT (dic)->key == IC_RESULT (ic)->key ||
1802 IC_LEFT (dic)->key == IC_RIGHT (ic)->key))
1808 if (POINTER_SET (dic) &&
1809 IC_RESULT (dic)->key == IC_RESULT (ic)->key)
1817 return 0; /* did not find */
1819 /* if assignment then check that right is not a bit */
1820 if (ASSIGNMENT (dic) && !POINTER_SET (dic))
1822 sym_link *etype = operandType (IC_RIGHT (dic));
1823 if (IS_BITFIELD (etype))
1825 /* if result is a bit too then it's ok */
1826 etype = operandType (IC_RESULT (dic));
1827 if (!IS_BITFIELD (etype))
1831 /* if the result is on stack or iaccess then it must be
1832 the same atleast one of the operands */
1833 if (OP_SYMBOL (IC_RESULT (ic))->onStack ||
1834 OP_SYMBOL (IC_RESULT (ic))->iaccess)
1837 /* the operation has only one symbol
1838 operator then we can pack */
1839 if ((IC_LEFT (dic) && !IS_SYMOP (IC_LEFT (dic))) ||
1840 (IC_RIGHT (dic) && !IS_SYMOP (IC_RIGHT (dic))))
1843 if (!((IC_LEFT (dic) &&
1844 IC_RESULT (ic)->key == IC_LEFT (dic)->key) ||
1846 IC_RESULT (ic)->key == IC_RIGHT (dic)->key)))
1850 /* found the definition */
1851 /* replace the result with the result of */
1852 /* this assignment and remove this assignment */
1853 bitVectUnSetBit(OP_SYMBOL(IC_RESULT(dic))->defs,dic->key);
1854 ReplaceOpWithCheaperOp(&IC_RESULT (dic), IC_RESULT (ic));
1856 if (IS_ITEMP (IC_RESULT (dic)) && OP_SYMBOL (IC_RESULT (dic))->liveFrom > dic->seq)
1858 OP_SYMBOL (IC_RESULT (dic))->liveFrom = dic->seq;
1860 // TODO: and the otherway around?
1862 /* delete from liverange table also
1863 delete from all the points inbetween and the new
1865 for (sic = dic; sic != ic; sic = sic->next)
1867 bitVectUnSetBit (sic->rlive, IC_RESULT (ic)->key);
1868 if (IS_ITEMP (IC_RESULT (dic)))
1869 bitVectSetBit (sic->rlive, IC_RESULT (dic)->key);
1872 remiCodeFromeBBlock (ebp, ic);
1873 bitVectUnSetBit(OP_SYMBOL(IC_RESULT(ic))->defs,ic->key);
1874 hTabDeleteItem (&iCodehTab, ic->key, ic, DELETE_ITEM, NULL);
1875 OP_DEFS(IC_RESULT (dic))=bitVectSetBit (OP_DEFS (IC_RESULT (dic)), dic->key);
1879 /*------------------------------------------------------------------*/
1880 /* findAssignToSym : scanning backwards looks for first assig found */
1881 /*------------------------------------------------------------------*/
1883 findAssignToSym (operand * op, iCode * ic)
1887 /* This routine is used to find sequences like
1889 ...; (intervening ops don't use iTempAA or modify FOO)
1890 blah = blah + iTempAA;
1892 and eliminate the use of iTempAA, freeing up its register for
1897 for (dic = ic->prev; dic; dic = dic->prev)
1900 /* if definition by assignment */
1901 if (dic->op == '=' &&
1902 !POINTER_SET (dic) &&
1903 IC_RESULT (dic)->key == op->key
1904 /* && IS_TRUE_SYMOP(IC_RIGHT(dic)) */
1906 break; /* found where this temp was defined */
1908 /* if we find an usage then we cannot delete it */
1909 if (IC_LEFT (dic) && IC_LEFT (dic)->key == op->key)
1912 if (IC_RIGHT (dic) && IC_RIGHT (dic)->key == op->key)
1915 if (POINTER_SET (dic) && IC_RESULT (dic)->key == op->key)
1920 return NULL; /* didn't find any assignment to op */
1922 /* we are interested only if defined in far space */
1923 /* or in stack space in case of + & - */
1925 /* if assigned to a non-symbol then don't repack regs */
1926 if (!IS_SYMOP (IC_RIGHT (dic)))
1929 /* if the symbol is volatile then we should not */
1930 if (isOperandVolatile (IC_RIGHT (dic), TRUE))
1932 /* XXX TODO --- should we be passing FALSE to isOperandVolatile()?
1933 What does it mean for an iTemp to be volatile, anyway? Passing
1934 TRUE is more cautious but may prevent possible optimizations */
1936 /* if the symbol is in far space then we should not */
1937 if (isOperandInFarSpace (IC_RIGHT (dic)))
1940 /* for + & - operations make sure that
1941 if it is on the stack it is the same
1942 as one of the three operands */
1943 if ((ic->op == '+' || ic->op == '-') &&
1944 OP_SYMBOL (IC_RIGHT (dic))->onStack)
1947 if (IC_RESULT (ic)->key != IC_RIGHT (dic)->key &&
1948 IC_LEFT (ic)->key != IC_RIGHT (dic)->key &&
1949 IC_RIGHT (ic)->key != IC_RIGHT (dic)->key)
1953 /* now make sure that the right side of dic
1954 is not defined between ic & dic */
1957 iCode *sic = dic->next;
1959 for (; sic != ic; sic = sic->next)
1960 if (IC_RESULT (sic) &&
1961 IC_RESULT (sic)->key == IC_RIGHT (dic)->key)
1968 /*-----------------------------------------------------------------*/
1969 /* reassignAliasedSym - used by packRegsForSupport to replace */
1970 /* redundant iTemp with equivalent symbol */
1971 /*-----------------------------------------------------------------*/
1973 reassignAliasedSym (eBBlock *ebp, iCode *assignment, iCode *use, operand *op)
1976 unsigned oldSymKey, newSymKey;
1978 oldSymKey = op->key;
1979 newSymKey = IC_RIGHT(assignment)->key;
1981 /* only track live ranges of compiler-generated temporaries */
1982 if (!IS_ITEMP(IC_RIGHT(assignment)))
1985 /* update the live-value bitmaps */
1986 for (ic = assignment; ic != use; ic = ic->next) {
1987 bitVectUnSetBit (ic->rlive, oldSymKey);
1989 ic->rlive = bitVectSetBit (ic->rlive, newSymKey);
1992 /* update the sym of the used operand */
1993 OP_SYMBOL(op) = OP_SYMBOL(IC_RIGHT(assignment));
1994 op->key = OP_SYMBOL(op)->key;
1996 /* update the sym's liverange */
1997 if ( OP_LIVETO(op) < ic->seq )
1998 setToRange(op, ic->seq, FALSE);
2000 /* remove the assignment iCode now that its result is unused */
2001 remiCodeFromeBBlock (ebp, assignment);
2002 bitVectUnSetBit(OP_SYMBOL(IC_RESULT(assignment))->defs, assignment->key);
2003 hTabDeleteItem (&iCodehTab, assignment->key, assignment, DELETE_ITEM, NULL);
2007 /*-----------------------------------------------------------------*/
2008 /* packRegsForSupport :- reduce some registers for support calls */
2009 /*-----------------------------------------------------------------*/
2011 packRegsForSupport (iCode * ic, eBBlock * ebp)
2015 /* for the left & right operand :- look to see if the
2016 left was assigned a true symbol in far space in that
2017 case replace them */
2019 if (IS_ITEMP (IC_LEFT (ic)) &&
2020 OP_SYMBOL (IC_LEFT (ic))->liveTo <= ic->seq)
2022 dic = findAssignToSym (IC_LEFT (ic), ic);
2026 /* found it we need to remove it from the block */
2027 reassignAliasedSym (ebp, dic, ic, IC_LEFT(ic));
2032 /* do the same for the right operand */
2033 if (IS_ITEMP (IC_RIGHT (ic)) &&
2034 OP_SYMBOL (IC_RIGHT (ic))->liveTo <= ic->seq)
2036 iCode *dic = findAssignToSym (IC_RIGHT (ic), ic);
2040 /* if this is a subtraction & the result
2041 is a true symbol in far space then don't pack */
2042 if (ic->op == '-' && IS_TRUE_SYMOP (IC_RESULT (dic)))
2044 sym_link *etype = getSpec (operandType (IC_RESULT (dic)));
2045 if (IN_FARSPACE (SPEC_OCLS (etype)))
2048 /* found it we need to remove it from the
2050 reassignAliasedSym (ebp, dic, ic, IC_RIGHT(ic));
2059 #define IS_OP_RUONLY(x) (x && IS_SYMOP(x) && OP_SYMBOL(x)->ruonly)
2062 /*-----------------------------------------------------------------*/
2063 /* packRegsForOneuse : - will reduce some registers for single Use */
2064 /*-----------------------------------------------------------------*/
2066 packRegsForOneuse (iCode * ic, operand * op, eBBlock * ebp)
2071 /* if returning a literal then do nothing */
2075 /* only upto 2 bytes since we cannot predict
2076 the usage of b, & acc */
2077 if (getSize (operandType (op)) > (fReturnSizeMCS51 - 2))
2080 if (ic->op != RETURN &&
2082 !POINTER_SET (ic) &&
2086 if (ic->op == SEND && ic->argreg != 1) return NULL;
2088 /* this routine will mark the a symbol as used in one
2089 instruction use only && if the defintion is local
2090 (ie. within the basic block) && has only one definition &&
2091 that definiion is either a return value from a
2092 function or does not contain any variables in
2094 uses = bitVectCopy (OP_USES (op));
2095 bitVectUnSetBit (uses, ic->key); /* take away this iCode */
2096 if (!bitVectIsZero (uses)) /* has other uses */
2099 /* if it has only one defintion */
2100 if (bitVectnBitsOn (OP_DEFS (op)) > 1)
2101 return NULL; /* has more than one definition */
2103 /* get that definition */
2105 hTabItemWithKey (iCodehTab,
2106 bitVectFirstBit (OP_DEFS (op)))))
2109 /* if that only usage is a cast */
2110 if (dic->op == CAST) {
2111 /* to a bigger type */
2112 if (getSize(OP_SYM_TYPE(IC_RESULT(dic))) >
2113 getSize(OP_SYM_TYPE(IC_RIGHT(dic)))) {
2114 /* than we can not, since we cannot predict the usage of b & acc */
2119 /* found the definition now check if it is local */
2120 if (dic->seq < ebp->fSeq ||
2121 dic->seq > ebp->lSeq)
2122 return NULL; /* non-local */
2124 /* now check if it is the return from
2126 if (dic->op == CALL || dic->op == PCALL)
2128 if (ic->op != SEND && ic->op != RETURN &&
2129 !POINTER_SET(ic) && !POINTER_GET(ic))
2131 OP_SYMBOL (op)->ruonly = 1;
2138 /* otherwise check that the definition does
2139 not contain any symbols in far space */
2140 if (isOperandInFarSpace (IC_LEFT (dic)) ||
2141 isOperandInFarSpace (IC_RIGHT (dic)) ||
2142 IS_OP_RUONLY (IC_LEFT (ic)) ||
2143 IS_OP_RUONLY (IC_RIGHT (ic)))
2148 /* if pointer set then make sure the pointer
2150 if (POINTER_SET (dic) &&
2151 !IS_DATA_PTR (aggrToPtr (operandType (IC_RESULT (dic)), FALSE)))
2154 if (POINTER_GET (dic) &&
2155 !IS_DATA_PTR (aggrToPtr (operandType (IC_LEFT (dic)), FALSE)))
2160 /* also make sure the intervenening instructions
2161 don't have any thing in far space */
2162 for (dic = dic->next; dic && dic != ic && sic != ic; dic = dic->next)
2165 /* if there is an intervening function call then no */
2166 if (dic->op == CALL || dic->op == PCALL)
2168 /* if pointer set then make sure the pointer
2170 if (POINTER_SET (dic) &&
2171 !IS_DATA_PTR (aggrToPtr (operandType (IC_RESULT (dic)), FALSE)))
2174 if (POINTER_GET (dic) &&
2175 !IS_DATA_PTR (aggrToPtr (operandType (IC_LEFT (dic)), FALSE)))
2178 /* if address of & the result is remat the okay */
2179 if (dic->op == ADDRESS_OF &&
2180 OP_SYMBOL (IC_RESULT (dic))->remat)
2183 /* if operand has size of three or more & this
2184 operation is a '*','/' or '%' then 'b' may
2186 if ((dic->op == '%' || dic->op == '/' || dic->op == '*') &&
2187 getSize (operandType (op)) >= 3)
2190 /* if left or right or result is in far space */
2191 if (isOperandInFarSpace (IC_LEFT (dic)) ||
2192 isOperandInFarSpace (IC_RIGHT (dic)) ||
2193 isOperandInFarSpace (IC_RESULT (dic)) ||
2194 IS_OP_RUONLY (IC_LEFT (dic)) ||
2195 IS_OP_RUONLY (IC_RIGHT (dic)) ||
2196 IS_OP_RUONLY (IC_RESULT (dic)))
2200 /* if left or right or result is on stack */
2201 if (isOperandOnStack(IC_LEFT(dic)) ||
2202 isOperandOnStack(IC_RIGHT(dic)) ||
2203 isOperandOnStack(IC_RESULT(dic))) {
2208 OP_SYMBOL (op)->ruonly = 1;
2212 /*-----------------------------------------------------------------*/
2213 /* isBitwiseOptimizable - requirements of JEAN LOUIS VERN */
2214 /*-----------------------------------------------------------------*/
2216 isBitwiseOptimizable (iCode * ic)
2218 sym_link *ltype = getSpec (operandType (IC_LEFT (ic)));
2219 sym_link *rtype = getSpec (operandType (IC_RIGHT (ic)));
2221 /* bitwise operations are considered optimizable
2222 under the following conditions (Jean-Louis VERN)
2234 if (IS_LITERAL(rtype) ||
2235 (IS_BITVAR (ltype) && IN_BITSPACE (SPEC_OCLS (ltype))))
2241 /*-----------------------------------------------------------------*/
2242 /* isCommutativeOp - tests whether this op cares what order its */
2243 /* operands are in */
2244 /*-----------------------------------------------------------------*/
2245 bool isCommutativeOp(unsigned int op)
2247 if (op == '+' || op == '*' || op == EQ_OP ||
2248 op == '^' || op == '|' || op == BITWISEAND)
2254 /*-----------------------------------------------------------------*/
2255 /* operandUsesAcc - determines whether the code generated for this */
2256 /* operand will have to use the accumulator */
2257 /*-----------------------------------------------------------------*/
2258 bool operandUsesAcc(operand *op)
2264 symbol *sym = OP_SYMBOL(op);
2268 return TRUE; /* duh! */
2270 if (IN_STACK(sym->etype) || sym->onStack ||
2271 (SPIL_LOC(op) && SPIL_LOC(op)->onStack))
2272 return TRUE; /* acc is used to calc stack offset */
2277 sym = SPIL_LOC(op); /* if spilled, look at spill location */
2279 return FALSE; /* more checks? */
2283 symspace = SPEC_OCLS(sym->etype);
2285 if (sym->iaccess && symspace->paged)
2286 return TRUE; /* must fetch paged indirect sym via accumulator */
2288 if (IN_BITSPACE(symspace))
2289 return TRUE; /* fetching bit vars uses the accumulator */
2291 if (IN_FARSPACE(symspace) || IN_CODESPACE(symspace))
2292 return TRUE; /* fetched via accumulator and dptr */
2298 /*-----------------------------------------------------------------*/
2299 /* packRegsForAccUse - pack registers for acc use */
2300 /*-----------------------------------------------------------------*/
2302 packRegsForAccUse (iCode * ic)
2306 /* if this is an aggregate, e.g. a one byte char array */
2307 if (IS_AGGREGATE(operandType(IC_RESULT(ic)))) {
2311 /* if we are calling a reentrant function that has stack parameters */
2312 if (ic->op == CALL &&
2313 IFFUNC_ISREENT(operandType(IC_LEFT(ic))) &&
2314 FUNC_HASSTACKPARM(operandType(IC_LEFT(ic))))
2317 if (ic->op == PCALL &&
2318 IFFUNC_ISREENT(operandType(IC_LEFT(ic))->next) &&
2319 FUNC_HASSTACKPARM(operandType(IC_LEFT(ic))->next))
2322 /* if + or - then it has to be one byte result */
2323 if ((ic->op == '+' || ic->op == '-')
2324 && getSize (operandType (IC_RESULT (ic))) > 1)
2327 /* if shift operation make sure right side is not a literal */
2328 if (ic->op == RIGHT_OP &&
2329 (isOperandLiteral (IC_RIGHT (ic)) ||
2330 getSize (operandType (IC_RESULT (ic))) > 1))
2333 if (ic->op == LEFT_OP &&
2334 (isOperandLiteral (IC_RIGHT (ic)) ||
2335 getSize (operandType (IC_RESULT (ic))) > 1))
2338 if (IS_BITWISE_OP (ic) &&
2339 getSize (operandType (IC_RESULT (ic))) > 1)
2343 /* has only one definition */
2344 if (bitVectnBitsOn (OP_DEFS (IC_RESULT (ic))) > 1)
2347 /* has only one use */
2348 if (bitVectnBitsOn (OP_USES (IC_RESULT (ic))) > 1)
2351 /* and the usage immediately follows this iCode */
2352 if (!(uic = hTabItemWithKey (iCodehTab,
2353 bitVectFirstBit (OP_USES (IC_RESULT (ic))))))
2356 if (ic->next != uic)
2359 /* if it is a conditional branch then we definitely can */
2363 if (uic->op == JUMPTABLE)
2366 if (POINTER_SET (uic) &&
2367 getSize (aggrToPtr (operandType (IC_RESULT (uic)), FALSE)) > 1)
2370 /* if the usage is not is an assignment
2371 or an arithmetic / bitwise / shift operation then not */
2372 if (uic->op != '=' &&
2373 !IS_ARITHMETIC_OP (uic) &&
2374 !IS_BITWISE_OP (uic) &&
2375 uic->op != LEFT_OP &&
2376 uic->op != RIGHT_OP)
2379 /* if used in ^ operation then make sure right is not a
2380 literal (WIML: Why is this?) */
2381 if (uic->op == '^' && isOperandLiteral (IC_RIGHT (uic)))
2384 /* if shift operation make sure right side is not a literal */
2385 /* WIML: Why is this? */
2386 if (uic->op == RIGHT_OP &&
2387 (isOperandLiteral (IC_RIGHT (uic)) ||
2388 getSize (operandType (IC_RESULT (uic))) > 1))
2390 if (uic->op == LEFT_OP &&
2391 (isOperandLiteral (IC_RIGHT (uic)) ||
2392 getSize (operandType (IC_RESULT (uic))) > 1))
2395 /* make sure that the result of this icode is not on the
2396 stack, since acc is used to compute stack offset */
2398 if (IS_TRUE_SYMOP (IC_RESULT (uic)) &&
2399 OP_SYMBOL (IC_RESULT (uic))->onStack)
2402 if (isOperandOnStack(IC_RESULT(uic)))
2406 /* if the usage has only one operand then we can */
2407 if (IC_LEFT (uic) == NULL ||
2408 IC_RIGHT (uic) == NULL)
2411 /* if the other operand uses the accumulator then we cannot */
2412 if ( (IC_LEFT(uic)->key == IC_RESULT(ic)->key &&
2413 operandUsesAcc(IC_RIGHT(uic))) ||
2414 (IC_RIGHT(uic)->key == IC_RESULT(ic)->key &&
2415 operandUsesAcc(IC_LEFT(uic))) )
2418 /* make sure this is on the left side if not commutative */
2419 /* except for '-', which has been written to be able to
2420 handle reversed operands */
2421 if (!(isCommutativeOp(ic->op) || ic->op == '-') &&
2422 IC_LEFT (uic)->key != IC_RESULT (ic)->key)
2426 // this is too dangerous and need further restrictions
2429 /* if one of them is a literal then we can */
2430 if ((IC_LEFT (uic) && IS_OP_LITERAL (IC_LEFT (uic))) ||
2431 (IC_RIGHT (uic) && IS_OP_LITERAL (IC_RIGHT (uic))))
2433 OP_SYMBOL (IC_RESULT (ic))->accuse = 1;
2439 OP_SYMBOL (IC_RESULT (ic))->accuse = 1;
2443 /*-----------------------------------------------------------------*/
2444 /* packForPush - hueristics to reduce iCode for pushing */
2445 /*-----------------------------------------------------------------*/
2447 packForPush (iCode * ic, eBBlock ** ebpp, int blockno)
2451 struct eBBlock * ebp=ebpp[blockno];
2453 if (ic->op != IPUSH || !IS_ITEMP (IC_LEFT (ic)))
2456 /* must have only definition & one usage */
2457 if (bitVectnBitsOn (OP_DEFS (IC_LEFT (ic))) != 1 ||
2458 bitVectnBitsOn (OP_USES (IC_LEFT (ic))) != 1)
2461 /* find the definition */
2462 if (!(dic = hTabItemWithKey (iCodehTab,
2463 bitVectFirstBit (OP_DEFS (IC_LEFT (ic))))))
2466 if (dic->op != '=' || POINTER_SET (dic))
2469 if (dic->seq < ebp->fSeq) { // Evelyn did this
2471 for (i=0; i<blockno; i++) {
2472 if (dic->seq >= ebpp[i]->fSeq && dic->seq <= ebpp[i]->lSeq) {
2477 wassert (i!=blockno); // no way to recover from here
2480 if (IS_SYMOP(IC_RIGHT(dic))) {
2481 /* make sure the right side does not have any definitions
2483 dbv = OP_DEFS(IC_RIGHT(dic));
2484 for (lic = ic; lic && lic != dic ; lic = lic->prev) {
2485 if (bitVectBitValue(dbv,lic->key))
2488 /* make sure they have the same type */
2489 if (IS_SPEC(operandType(IC_LEFT(ic))))
2491 sym_link *itype=operandType(IC_LEFT(ic));
2492 sym_link *ditype=operandType(IC_RIGHT(dic));
2494 if (SPEC_USIGN(itype)!=SPEC_USIGN(ditype) ||
2495 SPEC_LONG(itype)!=SPEC_LONG(ditype))
2498 /* extend the live range of replaced operand if needed */
2499 if (OP_SYMBOL(IC_RIGHT(dic))->liveTo < ic->seq) {
2500 OP_SYMBOL(IC_RIGHT(dic))->liveTo = ic->seq;
2502 bitVectUnSetBit(OP_SYMBOL(IC_RESULT(dic))->defs,dic->key);
2505 /* we now we know that it has one & only one def & use
2506 and the that the definition is an assignment */
2507 ReplaceOpWithCheaperOp(&IC_LEFT (ic), IC_RIGHT (dic));
2508 remiCodeFromeBBlock (ebp, dic);
2509 hTabDeleteItem (&iCodehTab, dic->key, dic, DELETE_ITEM, NULL);
2512 /*-----------------------------------------------------------------*/
2513 /* packRegisters - does some transformations to reduce register */
2515 /*-----------------------------------------------------------------*/
2517 packRegisters (eBBlock ** ebpp, int blockno)
2521 eBBlock *ebp=ebpp[blockno];
2528 /* look for assignments of the form */
2529 /* iTempNN = TRueSym (someoperation) SomeOperand */
2531 /* TrueSym := iTempNN:1 */
2532 for (ic = ebp->sch; ic; ic = ic->next)
2534 /* find assignment of the form TrueSym := iTempNN:1 */
2535 if (ic->op == '=' && !POINTER_SET (ic))
2536 change += packRegsForAssign (ic, ebp);
2543 for (ic = ebp->sch; ic; ic = ic->next)
2545 /* if this is an itemp & result of an address of a true sym
2546 then mark this as rematerialisable */
2547 if (ic->op == ADDRESS_OF &&
2548 IS_ITEMP (IC_RESULT (ic)) &&
2549 IS_TRUE_SYMOP (IC_LEFT (ic)) &&
2550 bitVectnBitsOn (OP_DEFS (IC_RESULT (ic))) == 1 &&
2551 !OP_SYMBOL (IC_LEFT (ic))->onStack)
2554 OP_SYMBOL (IC_RESULT (ic))->remat = 1;
2555 OP_SYMBOL (IC_RESULT (ic))->rematiCode = ic;
2556 OP_SYMBOL (IC_RESULT (ic))->usl.spillLoc = NULL;
2560 /* if straight assignment then carry remat flag if
2561 this is the only definition */
2562 if (ic->op == '=' &&
2563 !POINTER_SET (ic) &&
2564 IS_SYMOP (IC_RIGHT (ic)) &&
2565 OP_SYMBOL (IC_RIGHT (ic))->remat &&
2566 !IS_CAST_ICODE(OP_SYMBOL (IC_RIGHT (ic))->rematiCode) &&
2567 bitVectnBitsOn (OP_SYMBOL (IC_RESULT (ic))->defs) <= 1)
2570 OP_SYMBOL (IC_RESULT (ic))->remat =
2571 OP_SYMBOL (IC_RIGHT (ic))->remat;
2572 OP_SYMBOL (IC_RESULT (ic))->rematiCode =
2573 OP_SYMBOL (IC_RIGHT (ic))->rematiCode;
2576 /* if cast to a generic pointer & the pointer being
2577 cast is remat, then we can remat this cast as well */
2578 if (ic->op == CAST &&
2579 IS_SYMOP(IC_RIGHT(ic)) &&
2580 OP_SYMBOL(IC_RIGHT(ic))->remat &&
2581 bitVectnBitsOn (OP_DEFS (IC_RESULT (ic))) == 1) {
2582 sym_link *to_type = operandType(IC_LEFT(ic));
2583 sym_link *from_type = operandType(IC_RIGHT(ic));
2584 if (IS_GENPTR(to_type) && IS_PTR(from_type)) {
2585 OP_SYMBOL (IC_RESULT (ic))->remat = 1;
2586 OP_SYMBOL (IC_RESULT (ic))->rematiCode = ic;
2587 OP_SYMBOL (IC_RESULT (ic))->usl.spillLoc = NULL;
2591 /* if this is a +/- operation with a rematerizable
2592 then mark this as rematerializable as well */
2593 if ((ic->op == '+' || ic->op == '-') &&
2594 (IS_SYMOP (IC_LEFT (ic)) &&
2595 IS_ITEMP (IC_RESULT (ic)) &&
2596 IS_OP_LITERAL (IC_RIGHT (ic))) &&
2597 OP_SYMBOL (IC_LEFT (ic))->remat &&
2598 (!IS_SYMOP (IC_RIGHT (ic)) || !IS_CAST_ICODE(OP_SYMBOL (IC_RIGHT (ic))->rematiCode)) &&
2599 bitVectnBitsOn (OP_DEFS (IC_RESULT (ic))) == 1)
2601 OP_SYMBOL (IC_RESULT (ic))->remat = 1;
2602 OP_SYMBOL (IC_RESULT (ic))->rematiCode = ic;
2603 OP_SYMBOL (IC_RESULT (ic))->usl.spillLoc = NULL;
2606 /* mark the pointer usages */
2607 if (POINTER_SET (ic))
2608 OP_SYMBOL (IC_RESULT (ic))->uptr = 1;
2610 if (POINTER_GET (ic) &&
2611 IS_SYMOP(IC_LEFT (ic)))
2612 OP_SYMBOL (IC_LEFT (ic))->uptr = 1;
2616 /* if we are using a symbol on the stack
2617 then we should say mcs51_ptrRegReq */
2618 if (ic->op == IFX && IS_SYMOP (IC_COND (ic)))
2619 mcs51_ptrRegReq += ((OP_SYMBOL (IC_COND (ic))->onStack ||
2620 OP_SYMBOL (IC_COND (ic))->iaccess) ? 1 : 0);
2621 else if (ic->op == JUMPTABLE && IS_SYMOP (IC_JTCOND (ic)))
2622 mcs51_ptrRegReq += ((OP_SYMBOL (IC_JTCOND (ic))->onStack ||
2623 OP_SYMBOL (IC_JTCOND (ic))->iaccess) ? 1 : 0);
2626 if (IS_SYMOP (IC_LEFT (ic)))
2627 mcs51_ptrRegReq += ((OP_SYMBOL (IC_LEFT (ic))->onStack ||
2628 OP_SYMBOL (IC_LEFT (ic))->iaccess) ? 1 : 0);
2629 if (IS_SYMOP (IC_RIGHT (ic)))
2630 mcs51_ptrRegReq += ((OP_SYMBOL (IC_RIGHT (ic))->onStack ||
2631 OP_SYMBOL (IC_RIGHT (ic))->iaccess) ? 1 : 0);
2632 if (IS_SYMOP (IC_RESULT (ic)))
2633 mcs51_ptrRegReq += ((OP_SYMBOL (IC_RESULT (ic))->onStack ||
2634 OP_SYMBOL (IC_RESULT (ic))->iaccess) ? 1 : 0);
2638 /* if the condition of an if instruction
2639 is defined in the previous instruction and
2640 this is the only usage then
2641 mark the itemp as a conditional */
2642 if ((IS_CONDITIONAL (ic) ||
2643 (IS_BITWISE_OP(ic) && isBitwiseOptimizable (ic))) &&
2644 ic->next && ic->next->op == IFX &&
2645 bitVectnBitsOn (OP_USES(IC_RESULT(ic)))==1 &&
2646 isOperandEqual (IC_RESULT (ic), IC_COND (ic->next)) &&
2647 OP_SYMBOL (IC_RESULT (ic))->liveTo <= ic->next->seq)
2649 OP_SYMBOL (IC_RESULT (ic))->regType = REG_CND;
2653 /* reduce for support function calls */
2654 if (ic->supportRtn || ic->op == '+' || ic->op == '-')
2655 packRegsForSupport (ic, ebp);
2657 /* some cases the redundant moves can
2658 can be eliminated for return statements */
2659 if ((ic->op == RETURN || (ic->op == SEND && ic->argreg == 1)) &&
2660 !isOperandInFarSpace (IC_LEFT (ic)) &&
2661 options.model == MODEL_SMALL) {
2662 packRegsForOneuse (ic, IC_LEFT (ic), ebp);
2665 /* if pointer set & left has a size more than
2666 one and right is not in far space */
2667 if (POINTER_SET (ic) &&
2668 !isOperandInFarSpace (IC_RIGHT (ic)) &&
2669 !OP_SYMBOL (IC_RESULT (ic))->remat &&
2670 !IS_OP_RUONLY (IC_RIGHT (ic)) &&
2671 getSize (aggrToPtr (operandType (IC_RESULT (ic)), FALSE)) > 1)
2672 packRegsForOneuse (ic, IC_RESULT (ic), ebp);
2674 /* if pointer get */
2675 if (POINTER_GET (ic) &&
2676 IS_SYMOP (IC_LEFT (ic)) &&
2677 !isOperandInFarSpace (IC_RESULT (ic)) &&
2678 !OP_SYMBOL (IC_LEFT (ic))->remat &&
2679 !IS_OP_RUONLY (IC_RESULT (ic)) &&
2680 getSize (aggrToPtr (operandType (IC_LEFT (ic)), FALSE)) > 1)
2681 packRegsForOneuse (ic, IC_LEFT (ic), ebp);
2684 /* if this is cast for intergral promotion then
2685 check if only use of the definition of the
2686 operand being casted/ if yes then replace
2687 the result of that arithmetic operation with
2688 this result and get rid of the cast */
2691 sym_link *fromType = operandType (IC_RIGHT (ic));
2692 sym_link *toType = operandType (IC_LEFT (ic));
2694 if (IS_INTEGRAL (fromType) && IS_INTEGRAL (toType) &&
2695 getSize (fromType) != getSize (toType) &&
2696 SPEC_USIGN (fromType) == SPEC_USIGN (toType))
2699 iCode *dic = packRegsForOneuse (ic, IC_RIGHT (ic), ebp);
2702 if (IS_ARITHMETIC_OP (dic))
2704 bitVectUnSetBit(OP_SYMBOL(IC_RESULT(dic))->defs,dic->key);
2705 ReplaceOpWithCheaperOp(&IC_RESULT (dic), IC_RESULT (ic));
2706 remiCodeFromeBBlock (ebp, ic);
2707 bitVectUnSetBit(OP_SYMBOL(IC_RESULT(ic))->defs,ic->key);
2708 hTabDeleteItem (&iCodehTab, ic->key, ic, DELETE_ITEM, NULL);
2709 OP_DEFS(IC_RESULT (dic))=bitVectSetBit (OP_DEFS (IC_RESULT (dic)), dic->key);
2713 OP_SYMBOL (IC_RIGHT (ic))->ruonly = 0;
2719 /* if the type from and type to are the same
2720 then if this is the only use then packit */
2721 if (compareType (operandType (IC_RIGHT (ic)),
2722 operandType (IC_LEFT (ic))) == 1)
2724 iCode *dic = packRegsForOneuse (ic, IC_RIGHT (ic), ebp);
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);
2740 iTempNN := (some variable in farspace) V1
2745 if (ic->op == IPUSH)
2747 packForPush (ic, ebpp, blockno);
2751 /* pack registers for accumulator use, when the
2752 result of an arithmetic or bit wise operation
2753 has only one use, that use is immediately following
2754 the defintion and the using iCode has only one
2755 operand or has two operands but one is literal &
2756 the result of that operation is not on stack then
2757 we can leave the result of this operation in acc:b
2759 if ((IS_ARITHMETIC_OP (ic)
2760 || IS_CONDITIONAL(ic)
2761 || IS_BITWISE_OP (ic)
2762 || ic->op == LEFT_OP || ic->op == RIGHT_OP || ic->op == CALL
2763 || (ic->op == ADDRESS_OF && isOperandOnStack (IC_LEFT (ic)))
2765 IS_ITEMP (IC_RESULT (ic)) &&
2766 getSize (operandType (IC_RESULT (ic))) <= 2)
2768 packRegsForAccUse (ic);
2772 /*-----------------------------------------------------------------*/
2773 /* assignRegisters - assigns registers to each live range as need */
2774 /*-----------------------------------------------------------------*/
2776 mcs51_assignRegisters (eBBlock ** ebbs, int count)
2781 setToNull ((void *) &_G.funcrUsed);
2782 setToNull ((void *) &_G.regAssigned);
2783 setToNull ((void *) &_G.totRegAssigned);
2784 mcs51_ptrRegReq = _G.stackExtend = _G.dataExtend = 0;
2787 /* change assignments this will remove some
2788 live ranges reducing some register pressure */
2789 for (i = 0; i < count; i++)
2790 packRegisters (ebbs, i);
2792 if (options.dump_pack)
2793 dumpEbbsToFileExt (DUMP_PACK, ebbs, count);
2795 /* first determine for each live range the number of
2796 registers & the type of registers required for each */
2799 /* and serially allocate registers */
2800 serialRegAssign (ebbs, count);
2803 //setToNull ((void *) &_G.regAssigned);
2804 //setToNull ((void *) &_G.totRegAssigned);
2807 /* if stack was extended then tell the user */
2810 /* werror(W_TOOMANY_SPILS,"stack", */
2811 /* _G.stackExtend,currFunc->name,""); */
2817 /* werror(W_TOOMANY_SPILS,"data space", */
2818 /* _G.dataExtend,currFunc->name,""); */
2822 /* after that create the register mask
2823 for each of the instruction */
2824 createRegMask (ebbs, count);
2826 /* redo that offsets for stacked automatic variables */
2828 redoStackOffsets ();
2831 if (options.dump_rassgn)
2833 dumpEbbsToFileExt (DUMP_RASSGN, ebbs, count);
2834 dumpLiveRanges (DUMP_LRANGE, liveRanges);
2837 /* do the overlaysegment stuff SDCCmem.c */
2838 doOverlays (ebbs, count);
2840 /* now get back the chain */
2841 ic = iCodeLabelOptimize (iCodeFromeBBlock (ebbs, count));
2845 /* free up any _G.stackSpil locations allocated */
2846 applyToSet (_G.stackSpil, deallocStackSpil);
2848 setToNull ((void **) &_G.stackSpil);
2849 setToNull ((void **) &_G.spiltSet);
2850 /* mark all registers as free */