1 //#define LIVERANGEHUNT
7 /*------------------------------------------------------------------------
9 SDCCralloc.c - source file for register allocation. (8051) specific
11 Written By - Sandeep Dutta . sandeep.dutta@usa.net (1998)
13 This program is free software; you can redistribute it and/or modify it
14 under the terms of the GNU General Public License as published by the
15 Free Software Foundation; either version 2, or (at your option) any
18 This program is distributed in the hope that it will be useful,
19 but WITHOUT ANY WARRANTY; without even the implied warranty of
20 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
21 GNU General Public License for more details.
23 You should have received a copy of the GNU General Public License
24 along with this program; if not, write to the Free Software
25 Foundation, 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
27 In other words, you are welcome to use, share and improve this program.
28 You are forbidden to forbid anyone else to use, share and improve
29 what you give them. Help stamp out software-hoarding!
30 -------------------------------------------------------------------------*/
36 /*-----------------------------------------------------------------*/
37 /* At this point we start getting processor specific although */
38 /* some routines are non-processor specific & can be reused when */
39 /* targetting other processors. The decision for this will have */
40 /* to be made on a routine by routine basis */
41 /* routines used to pack registers are most definitely not reusable */
42 /* since the pack the registers depending strictly on the MCU */
43 /*-----------------------------------------------------------------*/
45 extern void gen51Code (iCode *);
54 bitVect *totRegAssigned; /* final set of LRs that got into registers */
57 bitVect *funcrUsed; /* registers used in a function */
63 /* Shared with gen.c */
64 int mcs51_ptrRegReq; /* one byte pointer register required */
70 {REG_GPR, R2_IDX, REG_GPR, "r2", "ar2", "0", 2, 1},
71 {REG_GPR, R3_IDX, REG_GPR, "r3", "ar3", "0", 3, 1},
72 {REG_GPR, R4_IDX, REG_GPR, "r4", "ar4", "0", 4, 1},
73 {REG_GPR, R5_IDX, REG_GPR, "r5", "ar5", "0", 5, 1},
74 {REG_GPR, R6_IDX, REG_GPR, "r6", "ar6", "0", 6, 1},
75 {REG_GPR, R7_IDX, REG_GPR, "r7", "ar7", "0", 7, 1},
76 {REG_PTR, R0_IDX, REG_PTR, "r0", "ar0", "0", 0, 1},
77 {REG_PTR, R1_IDX, REG_PTR, "r1", "ar1", "0", 1, 1},
78 {REG_GPR, X8_IDX, REG_GPR, "x8", "x8", "xreg", 0, 1},
79 {REG_GPR, X9_IDX, REG_GPR, "x9", "x9", "xreg", 1, 1},
80 {REG_GPR, X10_IDX, REG_GPR, "x10", "x10", "xreg", 2, 1},
81 {REG_GPR, X11_IDX, REG_GPR, "x11", "x11", "xreg", 3, 1},
82 {REG_GPR, X12_IDX, REG_GPR, "x12", "x12", "xreg", 4, 1},
83 {REG_CND, CND_IDX, REG_CND, "C", "C", "xreg", 0, 1},
86 static void spillThis (symbol *);
87 static void freeAllRegs ();
89 /*-----------------------------------------------------------------*/
90 /* allocReg - allocates register of given type */
91 /*-----------------------------------------------------------------*/
97 for (i = 0; i < mcs51_nRegs; i++)
100 /* if type is given as 0 then any
101 free register will do */
105 regs8051[i].isFree = 0;
108 bitVectSetBit (currFunc->regsUsed, i);
111 /* other wise look for specific type
113 if (regs8051[i].isFree &&
114 regs8051[i].type == type)
116 regs8051[i].isFree = 0;
119 bitVectSetBit (currFunc->regsUsed, i);
126 /*-----------------------------------------------------------------*/
127 /* mcs51_regWithIdx - returns pointer to register wit index number */
128 /*-----------------------------------------------------------------*/
130 mcs51_regWithIdx (int idx)
134 for (i = 0; i < mcs51_nRegs; i++)
135 if (regs8051[i].rIdx == idx)
138 werror (E_INTERNAL_ERROR, __FILE__, __LINE__,
139 "regWithIdx not found");
143 /*-----------------------------------------------------------------*/
144 /* freeReg - frees a register */
145 /*-----------------------------------------------------------------*/
151 werror (E_INTERNAL_ERROR, __FILE__, __LINE__,
152 "freeReg - Freeing NULL register");
160 /*-----------------------------------------------------------------*/
161 /* nFreeRegs - returns number of free registers */
162 /*-----------------------------------------------------------------*/
169 for (i = 0; i < mcs51_nRegs; i++)
170 if (regs8051[i].isFree && regs8051[i].type == type)
175 /*-----------------------------------------------------------------*/
176 /* nfreeRegsType - free registers with type */
177 /*-----------------------------------------------------------------*/
179 nfreeRegsType (int type)
184 if ((nfr = nFreeRegs (type)) == 0)
185 return nFreeRegs (REG_GPR);
188 return nFreeRegs (type);
191 /*-----------------------------------------------------------------*/
192 /* useReg - marks a register as used */
193 /*-----------------------------------------------------------------*/
200 /*-----------------------------------------------------------------*/
201 /* computeSpillable - given a point find the spillable live ranges */
202 /*-----------------------------------------------------------------*/
204 computeSpillable (iCode * ic)
208 /* spillable live ranges are those that are live at this
209 point . the following categories need to be subtracted
211 a) - those that are already spilt
212 b) - if being used by this one
213 c) - defined by this one */
215 spillable = bitVectCopy (ic->rlive);
217 bitVectCplAnd (spillable, _G.spiltSet); /* those already spilt */
219 bitVectCplAnd (spillable, ic->uses); /* used in this one */
220 bitVectUnSetBit (spillable, ic->defKey);
221 spillable = bitVectIntersect (spillable, _G.regAssigned);
226 /*-----------------------------------------------------------------*/
227 /* noSpilLoc - return true if a variable has no spil location */
228 /*-----------------------------------------------------------------*/
230 noSpilLoc (symbol * sym, eBBlock * ebp, iCode * ic)
232 return (sym->usl.spillLoc ? 0 : 1);
235 /*-----------------------------------------------------------------*/
236 /* hasSpilLoc - will return 1 if the symbol has spil location */
237 /*-----------------------------------------------------------------*/
239 hasSpilLoc (symbol * sym, eBBlock * ebp, iCode * ic)
241 return (sym->usl.spillLoc ? 1 : 0);
244 /*-----------------------------------------------------------------*/
245 /* directSpilLoc - will return 1 if the splilocation is in direct */
246 /*-----------------------------------------------------------------*/
248 directSpilLoc (symbol * sym, eBBlock * ebp, iCode * ic)
250 if (sym->usl.spillLoc &&
251 (IN_DIRSPACE (SPEC_OCLS (sym->usl.spillLoc->etype))))
257 /*-----------------------------------------------------------------*/
258 /* hasSpilLocnoUptr - will return 1 if the symbol has spil location */
259 /* but is not used as a pointer */
260 /*-----------------------------------------------------------------*/
262 hasSpilLocnoUptr (symbol * sym, eBBlock * ebp, iCode * ic)
264 return ((sym->usl.spillLoc && !sym->uptr) ? 1 : 0);
267 /*-----------------------------------------------------------------*/
268 /* rematable - will return 1 if the remat flag is set */
269 /*-----------------------------------------------------------------*/
271 rematable (symbol * sym, eBBlock * ebp, iCode * ic)
276 /*-----------------------------------------------------------------*/
277 /* notUsedInRemaining - not used or defined in remain of the block */
278 /*-----------------------------------------------------------------*/
280 notUsedInRemaining (symbol * sym, eBBlock * ebp, iCode * ic)
282 return ((usedInRemaining (operandFromSymbol (sym), ic) ? 0 : 1) &&
283 allDefsOutOfRange (sym->defs, ebp->fSeq, ebp->lSeq));
286 /*-----------------------------------------------------------------*/
287 /* allLRs - return true for all */
288 /*-----------------------------------------------------------------*/
290 allLRs (symbol * sym, eBBlock * ebp, iCode * ic)
295 /*-----------------------------------------------------------------*/
296 /* liveRangesWith - applies function to a given set of live range */
297 /*-----------------------------------------------------------------*/
299 liveRangesWith (bitVect * lrs, int (func) (symbol *, eBBlock *, iCode *),
300 eBBlock * ebp, iCode * ic)
305 if (!lrs || !lrs->size)
308 for (i = 1; i < lrs->size; i++)
311 if (!bitVectBitValue (lrs, i))
314 /* if we don't find it in the live range
315 hash table we are in serious trouble */
316 if (!(sym = hTabItemWithKey (liveRanges, i)))
318 werror (E_INTERNAL_ERROR, __FILE__, __LINE__,
319 "liveRangesWith could not find liveRange");
323 if (func (sym, ebp, ic) && bitVectBitValue (_G.regAssigned, sym->key))
324 addSetHead (&rset, sym);
331 /*-----------------------------------------------------------------*/
332 /* leastUsedLR - given a set determines which is the least used */
333 /*-----------------------------------------------------------------*/
335 leastUsedLR (set * sset)
337 symbol *sym = NULL, *lsym = NULL;
339 sym = lsym = setFirstItem (sset);
344 for (; lsym; lsym = setNextItem (sset))
347 /* if usage is the same then prefer
348 the spill the smaller of the two */
349 if (lsym->used == sym->used)
350 if (getSize (lsym->type) < getSize (sym->type))
354 if (lsym->used < sym->used)
359 setToNull ((void **) &sset);
364 /*-----------------------------------------------------------------*/
365 /* noOverLap - will iterate through the list looking for over lap */
366 /*-----------------------------------------------------------------*/
368 noOverLap (set * itmpStack, symbol * fsym)
373 for (sym = setFirstItem (itmpStack); sym;
374 sym = setNextItem (itmpStack))
376 if (bitVectBitValue(sym->clashes,fsym->key)) return 0;
382 /*-----------------------------------------------------------------*/
383 /* isFree - will return 1 if the a free spil location is found */
384 /*-----------------------------------------------------------------*/
389 V_ARG (symbol **, sloc);
390 V_ARG (symbol *, fsym);
392 /* if already found */
396 /* if it is free && and the itmp assigned to
397 this does not have any overlapping live ranges
398 with the one currently being assigned and
399 the size can be accomodated */
401 noOverLap (sym->usl.itmpStack, fsym) &&
402 getSize (sym->type) >= getSize (fsym->type))
411 /*-----------------------------------------------------------------*/
412 /* spillLRWithPtrReg :- will spil those live ranges which use PTR */
413 /*-----------------------------------------------------------------*/
415 spillLRWithPtrReg (symbol * forSym)
421 if (!_G.regAssigned ||
422 bitVectIsZero (_G.regAssigned))
425 r0 = mcs51_regWithIdx (R0_IDX);
426 r1 = mcs51_regWithIdx (R1_IDX);
428 /* for all live ranges */
429 for (lrsym = hTabFirstItem (liveRanges, &k); lrsym;
430 lrsym = hTabNextItem (liveRanges, &k))
434 /* if no registers assigned to it or spilt */
435 /* if it does not overlap with this then
436 not need to spill it */
438 if (lrsym->isspilt || !lrsym->nRegs ||
439 (lrsym->liveTo < forSym->liveFrom))
442 /* go thru the registers : if it is either
443 r0 or r1 then spil it */
444 for (j = 0; j < lrsym->nRegs; j++)
445 if (lrsym->regs[j] == r0 ||
446 lrsym->regs[j] == r1)
455 /*-----------------------------------------------------------------*/
456 /* createStackSpil - create a location on the stack to spil */
457 /*-----------------------------------------------------------------*/
459 createStackSpil (symbol * sym)
462 int useXstack, model;
466 /* first go try and find a free one that is already
467 existing on the stack */
468 if (applyToSet (_G.stackSpil, isFree, &sloc, sym))
470 /* found a free one : just update & return */
471 sym->usl.spillLoc = sloc;
474 addSetHead (&sloc->usl.itmpStack, sym);
478 /* could not then have to create one , this is the hard part
479 we need to allocate this on the stack : this is really a
480 hack!! but cannot think of anything better at this time */
482 if (sprintf (slocBuffer, "sloc%d", _G.slocNum++) >= sizeof (slocBuffer))
484 fprintf (stderr, "***Internal error: slocBuffer overflowed: %s:%d\n",
489 sloc = newiTemp (slocBuffer);
491 /* set the type to the spilling symbol */
492 sloc->type = copyLinkChain (sym->type);
493 sloc->etype = getSpec (sloc->type);
494 SPEC_SCLS (sloc->etype) = S_DATA;
495 SPEC_EXTR (sloc->etype) = 0;
496 SPEC_STAT (sloc->etype) = 0;
497 SPEC_VOLATILE(sloc->etype) = 0;
498 SPEC_ABSA(sloc->etype) = 0;
500 /* we don't allow it to be allocated`
501 onto the external stack since : so we
502 temporarily turn it off ; we also
503 turn off memory model to prevent
504 the spil from going to the external storage
507 useXstack = options.useXstack;
508 model = options.model;
509 /* noOverlay = options.noOverlay; */
510 /* options.noOverlay = 1; */
511 options.model = options.useXstack = 0;
515 options.useXstack = useXstack;
516 options.model = model;
517 /* options.noOverlay = noOverlay; */
518 sloc->isref = 1; /* to prevent compiler warning */
520 /* if it is on the stack then update the stack */
521 if (IN_STACK (sloc->etype))
523 currFunc->stack += getSize (sloc->type);
524 _G.stackExtend += getSize (sloc->type);
527 _G.dataExtend += getSize (sloc->type);
529 /* add it to the _G.stackSpil set */
530 addSetHead (&_G.stackSpil, sloc);
531 sym->usl.spillLoc = sloc;
534 /* add it to the set of itempStack set
535 of the spill location */
536 addSetHead (&sloc->usl.itmpStack, sym);
540 /*-----------------------------------------------------------------*/
541 /* isSpiltOnStack - returns true if the spil location is on stack */
542 /*-----------------------------------------------------------------*/
544 isSpiltOnStack (symbol * sym)
554 /* if (sym->_G.stackSpil) */
557 if (!sym->usl.spillLoc)
560 etype = getSpec (sym->usl.spillLoc->type);
561 if (IN_STACK (etype))
567 /*-----------------------------------------------------------------*/
568 /* spillThis - spils a specific operand */
569 /*-----------------------------------------------------------------*/
571 spillThis (symbol * sym)
574 /* if this is rematerializable or has a spillLocation
575 we are okay, else we need to create a spillLocation
577 if (!(sym->remat || sym->usl.spillLoc))
578 createStackSpil (sym);
580 LRH(printf("spillThis: %s\n", sym->name));
581 /* mark it has spilt & put it in the spilt set */
582 sym->isspilt = sym->spillA = 1;
583 _G.spiltSet = bitVectSetBit (_G.spiltSet, sym->key);
585 bitVectUnSetBit (_G.regAssigned, sym->key);
586 bitVectUnSetBit (_G.totRegAssigned, sym->key);
588 for (i = 0; i < sym->nRegs; i++)
592 freeReg (sym->regs[i]);
596 /* if spilt on stack then free up r0 & r1
597 if they could have been assigned to some
599 if (!mcs51_ptrRegReq && isSpiltOnStack (sym))
602 spillLRWithPtrReg (sym);
605 if (sym->usl.spillLoc && !sym->remat)
606 sym->usl.spillLoc->allocreq++;
610 /*-----------------------------------------------------------------*/
611 /* selectSpil - select a iTemp to spil : rather a simple procedure */
612 /*-----------------------------------------------------------------*/
614 selectSpil (iCode * ic, eBBlock * ebp, symbol * forSym)
616 bitVect *lrcs = NULL;
620 /* get the spillable live ranges */
621 lrcs = computeSpillable (ic);
623 /* get all live ranges that are rematerizable */
624 if ((selectS = liveRangesWith (lrcs, rematable, ebp, ic)))
627 /* return the least used of these */
628 return leastUsedLR (selectS);
631 /* get live ranges with spillLocations in direct space */
632 if ((selectS = liveRangesWith (lrcs, directSpilLoc, ebp, ic)))
634 sym = leastUsedLR (selectS);
635 strcpy (sym->rname, (sym->usl.spillLoc->rname[0] ?
636 sym->usl.spillLoc->rname :
637 sym->usl.spillLoc->name));
639 /* mark it as allocation required */
640 sym->usl.spillLoc->allocreq++;
644 /* if the symbol is local to the block then */
645 if (forSym->liveTo < ebp->lSeq)
648 /* check if there are any live ranges allocated
649 to registers that are not used in this block */
650 if (!_G.blockSpil && (selectS = liveRangesWith (lrcs, notUsedInBlock, ebp, ic)))
652 sym = leastUsedLR (selectS);
653 /* if this is not rematerializable */
662 /* check if there are any live ranges that not
663 used in the remainder of the block */
664 if (!_G.blockSpil && (selectS = liveRangesWith (lrcs, notUsedInRemaining, ebp, ic)))
666 sym = leastUsedLR (selectS);
679 /* find live ranges with spillocation && not used as pointers */
680 if ((selectS = liveRangesWith (lrcs, hasSpilLocnoUptr, ebp, ic)))
683 sym = leastUsedLR (selectS);
684 /* mark this as allocation required */
685 sym->usl.spillLoc->allocreq++;
689 /* find live ranges with spillocation */
690 if ((selectS = liveRangesWith (lrcs, hasSpilLoc, ebp, ic)))
693 sym = leastUsedLR (selectS);
694 sym->usl.spillLoc->allocreq++;
698 /* couldn't find then we need to create a spil
699 location on the stack , for which one? the least
701 if ((selectS = liveRangesWith (lrcs, noSpilLoc, ebp, ic)))
704 /* return a created spil location */
705 sym = createStackSpil (leastUsedLR (selectS));
706 sym->usl.spillLoc->allocreq++;
710 /* this is an extreme situation we will spill
711 this one : happens very rarely but it does happen */
717 /*-----------------------------------------------------------------*/
718 /* spilSomething - spil some variable & mark registers as free */
719 /*-----------------------------------------------------------------*/
721 spilSomething (iCode * ic, eBBlock * ebp, symbol * forSym)
726 /* get something we can spil */
727 ssym = selectSpil (ic, ebp, forSym);
728 LRH(printf("spilSomething: spilled %s for %s\n", ssym->name, forSym->name));
730 /* mark it as spilt */
731 ssym->isspilt = ssym->spillA = 1;
732 _G.spiltSet = bitVectSetBit (_G.spiltSet, ssym->key);
734 /* mark it as not register assigned &
735 take it away from the set */
736 bitVectUnSetBit (_G.regAssigned, ssym->key);
737 bitVectUnSetBit (_G.totRegAssigned, ssym->key);
739 /* mark the registers as free */
740 for (i = 0; i < ssym->nRegs; i++)
742 freeReg (ssym->regs[i]);
744 /* if spilt on stack then free up r0 & r1
745 if they could have been assigned to as gprs */
746 if (!mcs51_ptrRegReq && isSpiltOnStack (ssym))
749 spillLRWithPtrReg (ssym);
752 /* if this was a block level spil then insert push & pop
753 at the start & end of block respectively */
756 iCode *nic = newiCode (IPUSH, operandFromSymbol (ssym), NULL);
757 /* add push to the start of the block */
758 addiCodeToeBBlock (ebp, nic, (ebp->sch->op == LABEL ?
759 ebp->sch->next : ebp->sch));
760 nic = newiCode (IPOP, operandFromSymbol (ssym), NULL);
761 /* add pop to the end of the block */
762 addiCodeToeBBlock (ebp, nic, NULL);
765 /* if spilt because not used in the remainder of the
766 block then add a push before this instruction and
767 a pop at the end of the block */
768 if (ssym->remainSpil)
771 iCode *nic = newiCode (IPUSH, operandFromSymbol (ssym), NULL);
772 /* add push just before this instruction */
773 addiCodeToeBBlock (ebp, nic, ic);
775 nic = newiCode (IPOP, operandFromSymbol (ssym), NULL);
776 /* add pop to the end of the block */
777 addiCodeToeBBlock (ebp, nic, NULL);
786 /*-----------------------------------------------------------------*/
787 /* getRegPtr - will try for PTR if not a GPR type if not spil */
788 /*-----------------------------------------------------------------*/
790 getRegPtr (iCode * ic, eBBlock * ebp, symbol * sym)
795 /* try for a ptr type */
796 if ((reg = allocReg (REG_PTR)))
799 /* try for gpr type */
800 if ((reg = allocReg (REG_GPR)))
803 /* we have to spil */
804 if (!spilSomething (ic, ebp, sym))
807 /* this looks like an infinite loop but
808 in really selectSpil will abort */
812 /*-----------------------------------------------------------------*/
813 /* getRegGpr - will try for GPR if not spil */
814 /*-----------------------------------------------------------------*/
816 getRegGpr (iCode * ic, eBBlock * ebp, symbol * sym)
821 /* try for gpr type */
822 if ((reg = allocReg (REG_GPR)))
825 if (!mcs51_ptrRegReq)
826 if ((reg = allocReg (REG_PTR)))
829 /* we have to spil */
830 if (!spilSomething (ic, ebp, sym))
833 /* this looks like an infinite loop but
834 in really selectSpil will abort */
838 /*-----------------------------------------------------------------*/
839 /* getRegPtrNoSpil - get it cannot split */
840 /*-----------------------------------------------------------------*/
841 static regs *getRegPtrNoSpil()
845 /* try for a ptr type */
846 if ((reg = allocReg (REG_PTR)))
849 /* try for gpr type */
850 if ((reg = allocReg (REG_GPR)))
855 /* just to make the compiler happy */
859 /*-----------------------------------------------------------------*/
860 /* getRegGprNoSpil - get it cannot split */
861 /*-----------------------------------------------------------------*/
862 static regs *getRegGprNoSpil()
866 if ((reg = allocReg (REG_GPR)))
869 if (!mcs51_ptrRegReq)
870 if ((reg = allocReg (REG_PTR)))
875 /* just to make the compiler happy */
879 /*-----------------------------------------------------------------*/
880 /* symHasReg - symbol has a given register */
881 /*-----------------------------------------------------------------*/
883 symHasReg (symbol * sym, regs * reg)
887 for (i = 0; i < sym->nRegs; i++)
888 if (sym->regs[i] == reg)
894 /*-----------------------------------------------------------------*/
895 /* deassignLRs - check the live to and if they have registers & are */
896 /* not spilt then free up the registers */
897 /*-----------------------------------------------------------------*/
899 deassignLRs (iCode * ic, eBBlock * ebp)
905 for (sym = hTabFirstItem (liveRanges, &k); sym;
906 sym = hTabNextItem (liveRanges, &k))
910 /* if it does not end here */
911 if (sym->liveTo > ic->seq)
914 /* if it was spilt on stack then we can
915 mark the stack spil location as free */
920 sym->usl.spillLoc->isFree = 1;
926 if (!bitVectBitValue (_G.regAssigned, sym->key))
929 /* special case check if this is an IFX &
930 the privious one was a pop and the
931 previous one was not spilt then keep track
933 if (ic->op == IFX && ic->prev &&
934 ic->prev->op == IPOP &&
935 !ic->prev->parmPush &&
936 !OP_SYMBOL (IC_LEFT (ic->prev))->isspilt)
937 psym = OP_SYMBOL (IC_LEFT (ic->prev));
943 bitVectUnSetBit (_G.regAssigned, sym->key);
945 /* if the result of this one needs registers
946 and does not have it then assign it right
948 if (IC_RESULT (ic) &&
949 !(SKIP_IC2 (ic) || /* not a special icode */
950 ic->op == JUMPTABLE ||
956 (result = OP_SYMBOL (IC_RESULT (ic))) && /* has a result */
957 result->liveTo > ic->seq && /* and will live beyond this */
958 result->liveTo <= ebp->lSeq && /* does not go beyond this block */
959 result->regType == sym->regType && /* same register types */
960 result->nRegs && /* which needs registers */
961 !result->isspilt && /* and does not already have them */
963 !bitVectBitValue (_G.regAssigned, result->key) &&
964 /* the number of free regs + number of regs in this LR
965 can accomodate the what result Needs */
966 ((nfreeRegsType (result->regType) +
967 sym->nRegs) >= result->nRegs)
971 for (i = 0; i < result->nRegs; i++)
973 result->regs[i] = sym->regs[i];
975 result->regs[i] = getRegGpr (ic, ebp, result);
977 _G.regAssigned = bitVectSetBit (_G.regAssigned, result->key);
978 _G.totRegAssigned = bitVectSetBit (_G.totRegAssigned, result->key);
982 /* free the remaining */
983 for (; i < sym->nRegs; i++)
987 if (!symHasReg (psym, sym->regs[i]))
988 freeReg (sym->regs[i]);
991 freeReg (sym->regs[i]);
998 /*-----------------------------------------------------------------*/
999 /* reassignLR - reassign this to registers */
1000 /*-----------------------------------------------------------------*/
1002 reassignLR (operand * op)
1004 symbol *sym = OP_SYMBOL (op);
1007 /* not spilt any more */
1008 sym->isspilt = sym->spillA = sym->blockSpil = sym->remainSpil = 0;
1009 bitVectUnSetBit (_G.spiltSet, sym->key);
1011 _G.regAssigned = bitVectSetBit (_G.regAssigned, sym->key);
1012 _G.totRegAssigned = bitVectSetBit (_G.totRegAssigned, sym->key);
1016 for (i = 0; i < sym->nRegs; i++)
1017 sym->regs[i]->isFree = 0;
1020 /*-----------------------------------------------------------------*/
1021 /* willCauseSpill - determines if allocating will cause a spill */
1022 /*-----------------------------------------------------------------*/
1024 willCauseSpill (int nr, int rt)
1026 /* first check if there are any avlb registers
1027 of te type required */
1030 /* special case for pointer type
1031 if pointer type not avlb then
1032 check for type gpr */
1033 if (nFreeRegs (rt) >= nr)
1035 if (nFreeRegs (REG_GPR) >= nr)
1040 if (mcs51_ptrRegReq)
1042 if (nFreeRegs (rt) >= nr)
1047 if (nFreeRegs (REG_PTR) +
1048 nFreeRegs (REG_GPR) >= nr)
1053 /* it will cause a spil */
1057 /*-----------------------------------------------------------------*/
1058 /* positionRegs - the allocator can allocate same registers to res- */
1059 /* ult and operand, if this happens make sure they are in the same */
1060 /* position as the operand otherwise chaos results */
1061 /*-----------------------------------------------------------------*/
1063 positionRegs (symbol * result, symbol * opsym)
1065 int count = min (result->nRegs, opsym->nRegs);
1066 int i, j = 0, shared = 0;
1069 /* if the result has been spilt then cannot share */
1074 /* first make sure that they actually share */
1075 for (i = 0; i < count; i++)
1077 for (j = 0; j < count; j++)
1079 if (result->regs[i] == opsym->regs[j] && i != j)
1089 regs *tmp = result->regs[i];
1090 result->regs[i] = result->regs[j];
1091 result->regs[j] = tmp;
1098 /*-----------------------------------------------------------------*/
1099 /* serialRegAssign - serially allocate registers to the variables */
1100 /*-----------------------------------------------------------------*/
1102 serialRegAssign (eBBlock ** ebbs, int count)
1106 /* for all blocks */
1107 for (i = 0; i < count; i++) {
1111 if (ebbs[i]->noPath &&
1112 (ebbs[i]->entryLabel != entryLabel &&
1113 ebbs[i]->entryLabel != returnLabel))
1116 /* of all instructions do */
1117 for (ic = ebbs[i]->sch; ic; ic = ic->next) {
1119 /* if this is an ipop that means some live
1120 range will have to be assigned again */
1122 reassignLR (IC_LEFT (ic));
1124 /* if result is present && is a true symbol */
1125 if (IC_RESULT (ic) && ic->op != IFX &&
1126 IS_TRUE_SYMOP (IC_RESULT (ic)))
1127 OP_SYMBOL (IC_RESULT (ic))->allocreq++;
1129 /* take away registers from live
1130 ranges that end at this instruction */
1131 deassignLRs (ic, ebbs[i]);
1133 /* some don't need registers */
1134 if (SKIP_IC2 (ic) ||
1135 ic->op == JUMPTABLE ||
1139 (IC_RESULT (ic) && POINTER_SET (ic)))
1142 /* now we need to allocate registers
1143 only for the result */
1144 if (IC_RESULT (ic)) {
1145 symbol *sym = OP_SYMBOL (IC_RESULT (ic));
1151 /* if it does not need or is spilt
1152 or is already assigned to registers
1153 or will not live beyond this instructions */
1156 bitVectBitValue (_G.regAssigned, sym->key) ||
1157 sym->liveTo <= ic->seq)
1160 /* if some liverange has been spilt at the block level
1161 and this one live beyond this block then spil this
1163 if (_G.blockSpil && sym->liveTo > ebbs[i]->lSeq) {
1167 /* if trying to allocate this will cause
1168 a spill and there is nothing to spill
1169 or this one is rematerializable then
1171 willCS = willCauseSpill (sym->nRegs, sym->regType);
1172 spillable = computeSpillable (ic);
1173 if (sym->remat || (willCS && bitVectIsZero (spillable))) {
1178 if (strcmp(sym->name,"iTemp121")==0) {
1181 /* if it has a spillocation & is used less than
1182 all other live ranges then spill this */
1184 if (sym->usl.spillLoc) {
1185 symbol *leastUsed = leastUsedLR (liveRangesWith (spillable,
1186 allLRs, ebbs[i], ic));
1187 if (leastUsed && leastUsed->used > sym->used) {
1192 /* if none of the liveRanges have a spillLocation then better
1193 to spill this one than anything else already assigned to registers */
1194 if (liveRangesWith(spillable,noSpilLoc,ebbs[i],ic)) {
1195 /* if this is local to this block then we might find a block spil */
1196 if (!(sym->liveFrom >= ebbs[i]->fSeq && sym->liveTo <= ebbs[i]->lSeq)) {
1203 /* if we need ptr regs for the right side
1205 if (POINTER_GET (ic) && IS_SYMOP (IC_LEFT (ic))
1206 && getSize (OP_SYMBOL (IC_LEFT (ic))->type) <= (unsigned int) PTRSIZE) {
1210 /* else we assign registers to it */
1211 _G.regAssigned = bitVectSetBit (_G.regAssigned, sym->key);
1212 _G.totRegAssigned = bitVectSetBit (_G.totRegAssigned, sym->key);
1214 for (j = 0; j < sym->nRegs; j++) {
1215 if (sym->regType == REG_PTR)
1216 sym->regs[j] = getRegPtr (ic, ebbs[i], sym);
1218 sym->regs[j] = getRegGpr (ic, ebbs[i], sym);
1220 /* if the allocation failed which means
1221 this was spilt then break */
1222 if (!sym->regs[j]) {
1227 /* if it shares registers with operands make sure
1228 that they are in the same position */
1229 if (IC_LEFT (ic) && IS_SYMOP (IC_LEFT (ic)) &&
1230 OP_SYMBOL (IC_LEFT (ic))->nRegs && ic->op != '=') {
1231 positionRegs (OP_SYMBOL (IC_RESULT (ic)),
1232 OP_SYMBOL (IC_LEFT (ic)));
1234 /* do the same for the right operand */
1235 if (IC_RIGHT (ic) && IS_SYMOP (IC_RIGHT (ic)) &&
1236 OP_SYMBOL (IC_RIGHT (ic))->nRegs) {
1237 positionRegs (OP_SYMBOL (IC_RESULT (ic)),
1238 OP_SYMBOL (IC_RIGHT (ic)));
1251 /*-----------------------------------------------------------------*/
1252 /* fillGaps - Try to fill in the Gaps left by Pass1 */
1253 /*-----------------------------------------------------------------*/
1254 static void fillGaps()
1259 if (getenv("DISABLE_FILL_GAPS")) return;
1261 /* look for livernages that was spilt by the allocator */
1262 for (sym = hTabFirstItem(liveRanges,&key) ; sym ;
1263 sym = hTabNextItem(liveRanges,&key)) {
1268 if (!sym->spillA || !sym->clashes || sym->remat) continue ;
1270 /* find the liveRanges this one clashes with, that are
1271 still assigned to registers & mark the registers as used*/
1272 for ( i = 0 ; i < sym->clashes->size ; i ++) {
1276 if (bitVectBitValue(sym->clashes,i) == 0 || /* those that clash with this */
1277 bitVectBitValue(_G.totRegAssigned,i) == 0) /* and are still assigned to registers */
1280 clr = hTabItemWithKey(liveRanges,i);
1283 /* mark these registers as used */
1284 for (k = 0 ; k < clr->nRegs ; k++ )
1285 useReg(clr->regs[k]);
1288 if (willCauseSpill(sym->nRegs,sym->regType)) {
1289 /* NOPE :( clear all registers & and continue */
1294 /* THERE IS HOPE !!!! */
1295 for (i=0; i < sym->nRegs ; i++ ) {
1296 if (sym->regType == REG_PTR)
1297 sym->regs[i] = getRegPtrNoSpil ();
1299 sym->regs[i] = getRegGprNoSpil ();
1302 /* for all its definitions check if the registers
1303 allocated needs positioning NOTE: we can position
1304 only ONCE if more than One positioning required
1307 for (i = 0 ; i < sym->defs->size ; i++ ) {
1308 if (bitVectBitValue(sym->defs,i)) {
1310 if (!(ic = hTabItemWithKey(iCodehTab,i))) continue ;
1311 if (SKIP_IC(ic)) continue;
1312 assert(isSymbolEqual(sym,OP_SYMBOL(IC_RESULT(ic)))); /* just making sure */
1313 /* if left is assigned to registers */
1314 if (IS_SYMOP(IC_LEFT(ic)) &&
1315 bitVectBitValue(_G.totRegAssigned,OP_SYMBOL(IC_LEFT(ic))->key)) {
1316 pdone += positionRegs(sym,OP_SYMBOL(IC_LEFT(ic)));
1318 if (IS_SYMOP(IC_RIGHT(ic)) &&
1319 bitVectBitValue(_G.totRegAssigned,OP_SYMBOL(IC_RIGHT(ic))->key)) {
1320 pdone += positionRegs(sym,OP_SYMBOL(IC_RIGHT(ic)));
1322 if (pdone > 1) break;
1325 for (i = 0 ; i < sym->uses->size ; i++ ) {
1326 if (bitVectBitValue(sym->uses,i)) {
1328 if (!(ic = hTabItemWithKey(iCodehTab,i))) continue ;
1329 if (SKIP_IC(ic)) continue;
1330 if (!IS_ASSIGN_ICODE(ic)) continue ;
1332 /* if result is assigned to registers */
1333 if (IS_SYMOP(IC_RESULT(ic)) &&
1334 bitVectBitValue(_G.totRegAssigned,OP_SYMBOL(IC_RESULT(ic))->key)) {
1335 pdone += positionRegs(sym,OP_SYMBOL(IC_RESULT(ic)));
1337 if (pdone > 1) break;
1340 /* had to position more than once GIVE UP */
1342 /* UNDO all the changes we made to try this */
1344 for (i=0; i < sym->nRegs ; i++ ) {
1345 sym->regs[i] = NULL;
1348 D(printf ("Fill Gap gave up due to positioning for %s in function %s\n",sym->name, currFunc ? currFunc->name : "UNKNOWN"));
1351 D(printf ("FILLED GAP for %s in function %s\n",sym->name, currFunc ? currFunc->name : "UNKNOWN"));
1352 _G.totRegAssigned = bitVectSetBit(_G.totRegAssigned,sym->key);
1353 sym->isspilt = sym->spillA = 0 ;
1354 sym->usl.spillLoc->allocreq--;
1359 /*-----------------------------------------------------------------*/
1360 /* rUmaskForOp :- returns register mask for an operand */
1361 /*-----------------------------------------------------------------*/
1363 mcs51_rUmaskForOp (operand * op)
1369 /* only temporaries are assigned registers */
1373 sym = OP_SYMBOL (op);
1375 /* if spilt or no registers assigned to it
1377 if (sym->isspilt || !sym->nRegs)
1380 rumask = newBitVect (mcs51_nRegs);
1382 for (j = 0; j < sym->nRegs; j++)
1384 rumask = bitVectSetBit (rumask,
1385 sym->regs[j]->rIdx);
1391 /*-----------------------------------------------------------------*/
1392 /* regsUsedIniCode :- returns bit vector of registers used in iCode */
1393 /*-----------------------------------------------------------------*/
1395 regsUsedIniCode (iCode * ic)
1397 bitVect *rmask = newBitVect (mcs51_nRegs);
1399 /* do the special cases first */
1402 rmask = bitVectUnion (rmask,
1403 mcs51_rUmaskForOp (IC_COND (ic)));
1407 /* for the jumptable */
1408 if (ic->op == JUMPTABLE)
1410 rmask = bitVectUnion (rmask,
1411 mcs51_rUmaskForOp (IC_JTCOND (ic)));
1416 /* of all other cases */
1418 rmask = bitVectUnion (rmask,
1419 mcs51_rUmaskForOp (IC_LEFT (ic)));
1423 rmask = bitVectUnion (rmask,
1424 mcs51_rUmaskForOp (IC_RIGHT (ic)));
1427 rmask = bitVectUnion (rmask,
1428 mcs51_rUmaskForOp (IC_RESULT (ic)));
1434 /*-----------------------------------------------------------------*/
1435 /* createRegMask - for each instruction will determine the regsUsed */
1436 /*-----------------------------------------------------------------*/
1438 createRegMask (eBBlock ** ebbs, int count)
1442 /* for all blocks */
1443 for (i = 0; i < count; i++)
1447 if (ebbs[i]->noPath &&
1448 (ebbs[i]->entryLabel != entryLabel &&
1449 ebbs[i]->entryLabel != returnLabel))
1452 /* for all instructions */
1453 for (ic = ebbs[i]->sch; ic; ic = ic->next)
1458 if (SKIP_IC2 (ic) || !ic->rlive)
1461 /* first mark the registers used in this
1463 ic->rUsed = regsUsedIniCode (ic);
1464 _G.funcrUsed = bitVectUnion (_G.funcrUsed, ic->rUsed);
1466 /* now create the register mask for those
1467 registers that are in use : this is a
1468 super set of ic->rUsed */
1469 ic->rMask = newBitVect (mcs51_nRegs + 1);
1471 /* for all live Ranges alive at this point */
1472 for (j = 1; j < ic->rlive->size; j++)
1477 /* if not alive then continue */
1478 if (!bitVectBitValue (ic->rlive, j))
1481 /* find the live range we are interested in */
1482 if (!(sym = hTabItemWithKey (liveRanges, j)))
1484 werror (E_INTERNAL_ERROR, __FILE__, __LINE__,
1485 "createRegMask cannot find live range");
1486 fprintf(stderr, "\tmissing live range: key=%d\n", j);
1490 /* if no register assigned to it */
1491 if (!sym->nRegs || sym->isspilt)
1494 /* for all the registers allocated to it */
1495 for (k = 0; k < sym->nRegs; k++)
1498 bitVectSetBit (ic->rMask, sym->regs[k]->rIdx);
1504 /*-----------------------------------------------------------------*/
1505 /* rematStr - returns the rematerialized string for a remat var */
1506 /*-----------------------------------------------------------------*/
1508 rematStr (symbol * sym)
1511 iCode *ic = sym->rematiCode;
1516 /* if plus or minus print the right hand side */
1517 if (ic->op == '+' || ic->op == '-')
1519 sprintf (s, "0x%04x %c ", (int) operandLitValue (IC_RIGHT (ic)),
1522 ic = OP_SYMBOL (IC_LEFT (ic))->rematiCode;
1526 /* cast then continue */
1527 if (IS_CAST_ICODE(ic)) {
1528 ic = OP_SYMBOL (IC_RIGHT (ic))->rematiCode;
1531 /* we reached the end */
1532 sprintf (s, "%s", OP_SYMBOL (IC_LEFT (ic))->rname);
1539 /*-----------------------------------------------------------------*/
1540 /* regTypeNum - computes the type & number of registers required */
1541 /*-----------------------------------------------------------------*/
1543 regTypeNum (eBBlock *ebbs)
1549 /* for each live range do */
1550 for (sym = hTabFirstItem (liveRanges, &k); sym;
1551 sym = hTabNextItem (liveRanges, &k))
1554 /* if used zero times then no registers needed */
1555 if ((sym->liveTo - sym->liveFrom) == 0)
1559 /* if the live range is a temporary */
1563 /* if the type is marked as a conditional */
1564 if (sym->regType == REG_CND)
1567 /* if used in return only then we don't
1569 if (sym->ruonly || sym->accuse)
1571 if (IS_AGGREGATE (sym->type) || sym->isptr)
1572 sym->type = aggrToPtr (sym->type, FALSE);
1577 /* if this symbol has only one usage and that is an assignment
1578 to a ruonly, we don't need registers */
1579 // if this symbol has only one def
1580 if (bitVectnBitsOn (sym->defs)==1) {
1581 printf ("sym: %s has only one usage", sym->name);
1583 if ((ic = hTabItemWithKey (iCodehTab, bitVectFirstBit (sym->defs)))) {
1585 printf (" for a call ");
1586 // if this is only assigned to a ruonly
1587 if ((ic = hTabItemWithKey (iCodehTab, bitVectFirstBit (sym->defs)))) {
1589 if (OP_SYMBOL(IC_RESULT(ic))->ruonly) {
1590 printf("regTypeNum: %s assigned to %s\n", \
1591 sym->name, OP_SYMBOL(IC_RESULT(ic))->name);
1600 /* if the symbol has only one definition &
1601 that definition is a get_pointer */
1602 if (bitVectnBitsOn (sym->defs) == 1 &&
1603 (ic = hTabItemWithKey (iCodehTab,
1604 bitVectFirstBit (sym->defs))) &&
1607 !IS_BITVAR (sym->etype))
1611 /* and that pointer is remat in data space */
1612 if (OP_SYMBOL (IC_LEFT (ic))->remat &&
1613 !IS_CAST_ICODE(OP_SYMBOL (IC_LEFT (ic))->rematiCode) &&
1614 DCL_TYPE (aggrToPtr (operandType(IC_LEFT(ic)), FALSE)) == POINTER)
1616 /* create a psuedo symbol & force a spil */
1617 symbol *psym = newSymbol (rematStr (OP_SYMBOL (IC_LEFT (ic))), 1);
1618 psym->type = sym->type;
1619 psym->etype = sym->etype;
1620 strcpy (psym->rname, psym->name);
1622 sym->usl.spillLoc = psym;
1623 #if 0 // an alternative fix for bug #480076
1624 /* now this is a useless assignment to itself */
1625 remiCodeFromeBBlock (ebbs, ic);
1627 /* now this really is an assignment to itself, make it so;
1628 it will be optimized out later */
1630 ReplaceOpWithCheaperOp(&IC_RIGHT(ic), IC_RESULT(ic));
1636 /* if in data space or idata space then try to
1637 allocate pointer register */
1641 /* if not then we require registers */
1642 sym->nRegs = ((IS_AGGREGATE (sym->type) || sym->isptr) ?
1643 getSize (sym->type = aggrToPtr (sym->type, FALSE)) :
1644 getSize (sym->type));
1648 fprintf (stderr, "allocated more than 4 or 0 registers for type ");
1649 printTypeChain (sym->type, stderr);
1650 fprintf (stderr, "\n");
1653 /* determine the type of register required */
1654 if (sym->nRegs == 1 &&
1655 IS_PTR (sym->type) &&
1657 sym->regType = REG_PTR;
1659 sym->regType = REG_GPR;
1663 /* for the first run we don't provide */
1664 /* registers for true symbols we will */
1665 /* see how things go */
1671 /*-----------------------------------------------------------------*/
1672 /* freeAllRegs - mark all registers as free */
1673 /*-----------------------------------------------------------------*/
1679 for (i = 0; i < mcs51_nRegs; i++)
1680 regs8051[i].isFree = 1;
1683 /*-----------------------------------------------------------------*/
1684 /* deallocStackSpil - this will set the stack pointer back */
1685 /*-----------------------------------------------------------------*/
1687 DEFSETFUNC (deallocStackSpil)
1695 /*-----------------------------------------------------------------*/
1696 /* farSpacePackable - returns the packable icode for far variables */
1697 /*-----------------------------------------------------------------*/
1699 farSpacePackable (iCode * ic)
1703 /* go thru till we find a definition for the
1704 symbol on the right */
1705 for (dic = ic->prev; dic; dic = dic->prev)
1707 /* if the definition is a call then no */
1708 if ((dic->op == CALL || dic->op == PCALL) &&
1709 IC_RESULT (dic)->key == IC_RIGHT (ic)->key)
1714 /* if shift by unknown amount then not */
1715 if ((dic->op == LEFT_OP || dic->op == RIGHT_OP) &&
1716 IC_RESULT (dic)->key == IC_RIGHT (ic)->key)
1719 /* if pointer get and size > 1 */
1720 if (POINTER_GET (dic) &&
1721 getSize (aggrToPtr (operandType (IC_LEFT (dic)), FALSE)) > 1)
1724 if (POINTER_SET (dic) &&
1725 getSize (aggrToPtr (operandType (IC_RESULT (dic)), FALSE)) > 1)
1728 /* if any three is a true symbol in far space */
1729 if (IC_RESULT (dic) &&
1730 IS_TRUE_SYMOP (IC_RESULT (dic)) &&
1731 isOperandInFarSpace (IC_RESULT (dic)))
1734 if (IC_RIGHT (dic) &&
1735 IS_TRUE_SYMOP (IC_RIGHT (dic)) &&
1736 isOperandInFarSpace (IC_RIGHT (dic)) &&
1737 !isOperandEqual (IC_RIGHT (dic), IC_RESULT (ic)))
1740 if (IC_LEFT (dic) &&
1741 IS_TRUE_SYMOP (IC_LEFT (dic)) &&
1742 isOperandInFarSpace (IC_LEFT (dic)) &&
1743 !isOperandEqual (IC_LEFT (dic), IC_RESULT (ic)))
1746 if (isOperandEqual (IC_RIGHT (ic), IC_RESULT (dic)))
1748 if ((dic->op == LEFT_OP ||
1749 dic->op == RIGHT_OP ||
1751 IS_OP_LITERAL (IC_RIGHT (dic)))
1761 /*-----------------------------------------------------------------*/
1762 /* packRegsForAssign - register reduction for assignment */
1763 /*-----------------------------------------------------------------*/
1765 packRegsForAssign (iCode * ic, eBBlock * ebp)
1769 if (!IS_ITEMP (IC_RIGHT (ic)) ||
1770 OP_SYMBOL (IC_RIGHT (ic))->isind ||
1771 OP_LIVETO (IC_RIGHT (ic)) > ic->seq)
1777 /* if the true symbol is defined in far space or on stack
1778 then we should not since this will increase register pressure */
1779 if (isOperandInFarSpace(IC_RESULT(ic)) && !farSpacePackable(ic)) {
1783 /* find the definition of iTempNN scanning backwards if we find a
1784 a use of the true symbol in before we find the definition then
1786 for (dic = ic->prev; dic; dic = dic->prev)
1788 /* if there is a function call then don't pack it */
1789 if ((dic->op == CALL || dic->op == PCALL))
1798 if (IS_TRUE_SYMOP (IC_RESULT (dic)) &&
1799 IS_OP_VOLATILE (IC_RESULT (dic)))
1805 if (IS_SYMOP (IC_RESULT (dic)) &&
1806 IC_RESULT (dic)->key == IC_RIGHT (ic)->key)
1808 if (POINTER_SET (dic))
1814 if (IS_SYMOP (IC_RIGHT (dic)) &&
1815 (IC_RIGHT (dic)->key == IC_RESULT (ic)->key ||
1816 IC_RIGHT (dic)->key == IC_RIGHT (ic)->key))
1822 if (IS_SYMOP (IC_LEFT (dic)) &&
1823 (IC_LEFT (dic)->key == IC_RESULT (ic)->key ||
1824 IC_LEFT (dic)->key == IC_RIGHT (ic)->key))
1830 if (POINTER_SET (dic) &&
1831 IC_RESULT (dic)->key == IC_RESULT (ic)->key)
1839 return 0; /* did not find */
1841 /* if assignment then check that right is not a bit */
1842 if (ASSIGNMENT (dic) && !POINTER_SET (dic))
1844 sym_link *etype = operandType (IC_RIGHT (dic));
1845 if (IS_BITFIELD (etype))
1848 /* if the result is on stack or iaccess then it must be
1849 the same atleast one of the operands */
1850 if (OP_SYMBOL (IC_RESULT (ic))->onStack ||
1851 OP_SYMBOL (IC_RESULT (ic))->iaccess)
1854 /* the operation has only one symbol
1855 operator then we can pack */
1856 if ((IC_LEFT (dic) && !IS_SYMOP (IC_LEFT (dic))) ||
1857 (IC_RIGHT (dic) && !IS_SYMOP (IC_RIGHT (dic))))
1860 if (!((IC_LEFT (dic) &&
1861 IC_RESULT (ic)->key == IC_LEFT (dic)->key) ||
1863 IC_RESULT (ic)->key == IC_RIGHT (dic)->key)))
1867 /* found the definition */
1868 /* replace the result with the result of */
1869 /* this assignment and remove this assignment */
1870 bitVectUnSetBit(OP_SYMBOL(IC_RESULT(dic))->defs,dic->key);
1871 ReplaceOpWithCheaperOp(&IC_RESULT (dic), IC_RESULT (ic));
1873 if (IS_ITEMP (IC_RESULT (dic)) && OP_SYMBOL (IC_RESULT (dic))->liveFrom > dic->seq)
1875 OP_SYMBOL (IC_RESULT (dic))->liveFrom = dic->seq;
1877 // jwk: and the otherway around?
1879 /* delete from liverange table also
1880 delete from all the points inbetween and the new
1882 for (sic = dic; sic != ic; sic = sic->next)
1884 bitVectUnSetBit (sic->rlive, IC_RESULT (ic)->key);
1885 if (IS_ITEMP (IC_RESULT (dic)))
1886 bitVectSetBit (sic->rlive, IC_RESULT (dic)->key);
1889 remiCodeFromeBBlock (ebp, ic);
1890 bitVectUnSetBit(OP_SYMBOL(IC_RESULT(ic))->defs,ic->key);
1891 hTabDeleteItem (&iCodehTab, ic->key, ic, DELETE_ITEM, NULL);
1892 OP_DEFS_SET ((IC_RESULT (dic)), bitVectSetBit (OP_DEFS (IC_RESULT (dic)), dic->key));
1896 /*------------------------------------------------------------------*/
1897 /* findAssignToSym : scanning backwards looks for first assig found */
1898 /*------------------------------------------------------------------*/
1900 findAssignToSym (operand * op, iCode * ic)
1904 /* This routine is used to find sequences like
1906 ...; (intervening ops don't use iTempAA or modify FOO)
1907 blah = blah + iTempAA;
1909 and eliminate the use of iTempAA, freeing up its register for
1914 for (dic = ic->prev; dic; dic = dic->prev)
1917 /* if definition by assignment */
1918 if (dic->op == '=' &&
1919 !POINTER_SET (dic) &&
1920 IC_RESULT (dic)->key == op->key
1921 /* && IS_TRUE_SYMOP(IC_RIGHT(dic)) */
1923 break; /* found where this temp was defined */
1925 /* if we find an usage then we cannot delete it */
1926 if (IC_LEFT (dic) && IC_LEFT (dic)->key == op->key)
1929 if (IC_RIGHT (dic) && IC_RIGHT (dic)->key == op->key)
1932 if (POINTER_SET (dic) && IC_RESULT (dic)->key == op->key)
1937 return NULL; /* didn't find any assignment to op */
1939 LRH(printf ("findAssignToSym: %s\n", OP_SYMBOL(IC_RESULT(dic))->name));
1940 /* we are interested only if defined in far space */
1941 /* or in stack space in case of + & - */
1943 /* if assigned to a non-symbol then don't repack regs */
1944 if (!IS_SYMOP (IC_RIGHT (dic)))
1947 /* if the symbol is volatile then we should not */
1948 if (isOperandVolatile (IC_RIGHT (dic), TRUE))
1950 /* XXX TODO --- should we be passing FALSE to isOperandVolatile()?
1951 What does it mean for an iTemp to be volatile, anyway? Passing
1952 TRUE is more cautious but may prevent possible optimizations */
1954 /* if the symbol is in far space then we should not */
1955 if (isOperandInFarSpace (IC_RIGHT (dic)))
1958 /* for + & - operations make sure that
1959 if it is on the stack it is the same
1960 as one of the three operands */
1961 if ((ic->op == '+' || ic->op == '-') &&
1962 OP_SYMBOL (IC_RIGHT (dic))->onStack)
1965 if (IC_RESULT (ic)->key != IC_RIGHT (dic)->key &&
1966 IC_LEFT (ic)->key != IC_RIGHT (dic)->key &&
1967 IC_RIGHT (ic)->key != IC_RIGHT (dic)->key)
1971 /* now make sure that the right side of dic
1972 is not defined between ic & dic */
1975 iCode *sic = dic->next;
1977 for (; sic != ic; sic = sic->next)
1978 if (IC_RESULT (sic) &&
1979 IC_RESULT (sic)->key == IC_RIGHT (dic)->key)
1986 /*-----------------------------------------------------------------*/
1987 /* reassignAliasedSym - used by packRegsForSupport to replace */
1988 /* redundant iTemp with equivalent symbol */
1989 /*-----------------------------------------------------------------*/
1991 reassignAliasedSym (eBBlock *ebp, iCode *assignment, iCode *use, operand *op)
1994 unsigned oldSymKey, newSymKey;
1996 oldSymKey = op->key;
1997 newSymKey = IC_RIGHT(assignment)->key;
1999 /* only track live ranges of compiler-generated temporaries */
2000 if (!IS_ITEMP(IC_RIGHT(assignment)))
2003 /* update the live-value bitmaps */
2004 for (ic = assignment; ic != use; ic = ic->next) {
2005 bitVectUnSetBit (ic->rlive, oldSymKey);
2007 ic->rlive = bitVectSetBit (ic->rlive, newSymKey);
2010 /* update the sym of the used operand */
2011 OP_SYMBOL(op) = OP_SYMBOL(IC_RIGHT(assignment));
2012 op->key = OP_SYMBOL(op)->key;
2014 /* update the sym's liverange */
2015 if ( OP_LIVETO(op) < ic->seq )
2016 setToRange(op, ic->seq, FALSE);
2018 /* remove the assignment iCode now that its result is unused */
2019 remiCodeFromeBBlock (ebp, assignment);
2020 bitVectUnSetBit(OP_SYMBOL(IC_RESULT(assignment))->defs, assignment->key);
2021 hTabDeleteItem (&iCodehTab, assignment->key, assignment, DELETE_ITEM, NULL);
2025 /*-----------------------------------------------------------------*/
2026 /* packRegsForSupport :- reduce some registers for support calls */
2027 /*-----------------------------------------------------------------*/
2029 packRegsForSupport (iCode * ic, eBBlock * ebp)
2033 /* for the left & right operand :- look to see if the
2034 left was assigned a true symbol in far space in that
2035 case replace them */
2037 if (IS_ITEMP (IC_LEFT (ic)) &&
2038 OP_SYMBOL (IC_LEFT (ic))->liveTo <= ic->seq)
2040 dic = findAssignToSym (IC_LEFT (ic), ic);
2044 /* found it we need to remove it from the block */
2045 reassignAliasedSym (ebp, dic, ic, IC_LEFT(ic));
2050 /* do the same for the right operand */
2051 if (IS_ITEMP (IC_RIGHT (ic)) &&
2052 OP_SYMBOL (IC_RIGHT (ic))->liveTo <= ic->seq)
2054 iCode *dic = findAssignToSym (IC_RIGHT (ic), ic);
2058 /* if this is a subtraction & the result
2059 is a true symbol in far space then don't pack */
2060 if (ic->op == '-' && IS_TRUE_SYMOP (IC_RESULT (dic)))
2062 sym_link *etype = getSpec (operandType (IC_RESULT (dic)));
2063 if (IN_FARSPACE (SPEC_OCLS (etype)))
2066 /* found it we need to remove it from the
2068 reassignAliasedSym (ebp, dic, ic, IC_RIGHT(ic));
2077 #define IS_OP_RUONLY(x) (x && IS_SYMOP(x) && OP_SYMBOL(x)->ruonly)
2080 /*-----------------------------------------------------------------*/
2081 /* packRegsForOneuse : - will reduce some registers for single Use */
2082 /*-----------------------------------------------------------------*/
2084 packRegsForOneuse (iCode * ic, operand * op, eBBlock * ebp)
2089 /* if returning a literal then do nothing */
2093 /* only upto 2 bytes since we cannot predict
2094 the usage of b, & acc */
2095 if (getSize (operandType (op)) > (fReturnSizeMCS51 - 2))
2098 if (ic->op != RETURN &&
2100 !POINTER_SET (ic) &&
2104 if (ic->op == SEND && ic->argreg != 1) return NULL;
2106 /* this routine will mark the a symbol as used in one
2107 instruction use only && if the defintion is local
2108 (ie. within the basic block) && has only one definition &&
2109 that definiion is either a return value from a
2110 function or does not contain any variables in
2112 uses = bitVectCopy (OP_USES (op));
2113 bitVectUnSetBit (uses, ic->key); /* take away this iCode */
2114 if (!bitVectIsZero (uses)) /* has other uses */
2117 /* if it has only one defintion */
2118 if (bitVectnBitsOn (OP_DEFS (op)) > 1)
2119 return NULL; /* has more than one definition */
2121 /* get that definition */
2123 hTabItemWithKey (iCodehTab,
2124 bitVectFirstBit (OP_DEFS (op)))))
2127 LRH(printf ("packRegsForOneUse: %s\n", OP_SYMBOL(op)->name));
2128 /* if that only usage is a cast */
2129 if (dic->op == CAST) {
2130 /* to a bigger type */
2131 if (getSize(OP_SYM_TYPE(IC_RESULT(dic))) >
2132 getSize(OP_SYM_TYPE(IC_RIGHT(dic)))) {
2133 /* than we can not, since we cannot predict the usage of b & acc */
2138 /* found the definition now check if it is local */
2139 if (dic->seq < ebp->fSeq ||
2140 dic->seq > ebp->lSeq)
2141 return NULL; /* non-local */
2143 /* now check if it is the return from
2145 if (dic->op == CALL || dic->op == PCALL)
2147 if (ic->op != SEND && ic->op != RETURN &&
2148 !POINTER_SET(ic) && !POINTER_GET(ic))
2150 OP_SYMBOL (op)->ruonly = 1;
2157 /* otherwise check that the definition does
2158 not contain any symbols in far space */
2159 if (isOperandInFarSpace (IC_LEFT (dic)) ||
2160 isOperandInFarSpace (IC_RIGHT (dic)) ||
2161 IS_OP_RUONLY (IC_LEFT (ic)) ||
2162 IS_OP_RUONLY (IC_RIGHT (ic)))
2167 /* if pointer set then make sure the pointer
2169 if (POINTER_SET (dic) &&
2170 !IS_DATA_PTR (aggrToPtr (operandType (IC_RESULT (dic)), FALSE)))
2173 if (POINTER_GET (dic) &&
2174 !IS_DATA_PTR (aggrToPtr (operandType (IC_LEFT (dic)), FALSE)))
2179 /* also make sure the intervenening instructions
2180 don't have any thing in far space */
2181 for (dic = dic->next; dic && dic != ic && sic != ic; dic = dic->next)
2184 /* if there is an intervening function call then no */
2185 if (dic->op == CALL || dic->op == PCALL)
2187 /* if pointer set then make sure the pointer
2189 if (POINTER_SET (dic) &&
2190 !IS_DATA_PTR (aggrToPtr (operandType (IC_RESULT (dic)), FALSE)))
2193 if (POINTER_GET (dic) &&
2194 !IS_DATA_PTR (aggrToPtr (operandType (IC_LEFT (dic)), FALSE)))
2197 /* if address of & the result is remat the okay */
2198 if (dic->op == ADDRESS_OF &&
2199 OP_SYMBOL (IC_RESULT (dic))->remat)
2202 /* if operand has size of three or more & this
2203 operation is a '*','/' or '%' then 'b' may
2205 if ((dic->op == '%' || dic->op == '/' || dic->op == '*') &&
2206 getSize (operandType (op)) >= 3)
2209 /* if left or right or result is in far space */
2210 if (isOperandInFarSpace (IC_LEFT (dic)) ||
2211 isOperandInFarSpace (IC_RIGHT (dic)) ||
2212 isOperandInFarSpace (IC_RESULT (dic)) ||
2213 IS_OP_RUONLY (IC_LEFT (dic)) ||
2214 IS_OP_RUONLY (IC_RIGHT (dic)) ||
2215 IS_OP_RUONLY (IC_RESULT (dic)))
2219 /* if left or right or result is on stack */
2220 if (isOperandOnStack(IC_LEFT(dic)) ||
2221 isOperandOnStack(IC_RIGHT(dic)) ||
2222 isOperandOnStack(IC_RESULT(dic))) {
2227 OP_SYMBOL (op)->ruonly = 1;
2231 /*-----------------------------------------------------------------*/
2232 /* isBitwiseOptimizable - requirements of JEAN LOUIS VERN */
2233 /*-----------------------------------------------------------------*/
2235 isBitwiseOptimizable (iCode * ic)
2237 sym_link *ltype = getSpec (operandType (IC_LEFT (ic)));
2238 sym_link *rtype = getSpec (operandType (IC_RIGHT (ic)));
2240 /* bitwise operations are considered optimizable
2241 under the following conditions (Jean-Louis VERN)
2253 if (IS_LITERAL(rtype) ||
2254 (IS_BITVAR (ltype) && IN_BITSPACE (SPEC_OCLS (ltype))))
2260 /*-----------------------------------------------------------------*/
2261 /* isCommutativeOp - tests whether this op cares what order its */
2262 /* operands are in */
2263 /*-----------------------------------------------------------------*/
2264 bool isCommutativeOp(unsigned int op)
2266 if (op == '+' || op == '*' || op == EQ_OP ||
2267 op == '^' || op == '|' || op == BITWISEAND)
2273 /*-----------------------------------------------------------------*/
2274 /* operandUsesAcc - determines whether the code generated for this */
2275 /* operand will have to use the accumulator */
2276 /*-----------------------------------------------------------------*/
2277 bool operandUsesAcc(operand *op)
2283 symbol *sym = OP_SYMBOL(op);
2287 return TRUE; /* duh! */
2289 if (IN_STACK(sym->etype) || sym->onStack ||
2290 (SPIL_LOC(op) && SPIL_LOC(op)->onStack))
2291 return TRUE; /* acc is used to calc stack offset */
2296 sym = SPIL_LOC(op); /* if spilled, look at spill location */
2298 return FALSE; /* more checks? */
2302 symspace = SPEC_OCLS(sym->etype);
2304 if (sym->iaccess && symspace->paged)
2305 return TRUE; /* must fetch paged indirect sym via accumulator */
2307 if (IN_BITSPACE(symspace))
2308 return TRUE; /* fetching bit vars uses the accumulator */
2310 if (IN_FARSPACE(symspace) || IN_CODESPACE(symspace))
2311 return TRUE; /* fetched via accumulator and dptr */
2317 /*-----------------------------------------------------------------*/
2318 /* packRegsForAccUse - pack registers for acc use */
2319 /*-----------------------------------------------------------------*/
2321 packRegsForAccUse (iCode * ic)
2325 /* if this is an aggregate, e.g. a one byte char array */
2326 if (IS_AGGREGATE(operandType(IC_RESULT(ic)))) {
2330 /* if we are calling a reentrant function that has stack parameters */
2331 if (ic->op == CALL &&
2332 IFFUNC_ISREENT(operandType(IC_LEFT(ic))) &&
2333 FUNC_HASSTACKPARM(operandType(IC_LEFT(ic))))
2336 if (ic->op == PCALL &&
2337 IFFUNC_ISREENT(operandType(IC_LEFT(ic))->next) &&
2338 FUNC_HASSTACKPARM(operandType(IC_LEFT(ic))->next))
2341 /* if + or - then it has to be one byte result */
2342 if ((ic->op == '+' || ic->op == '-')
2343 && getSize (operandType (IC_RESULT (ic))) > 1)
2346 /* if shift operation make sure right side is not a literal */
2347 if (ic->op == RIGHT_OP &&
2348 (isOperandLiteral (IC_RIGHT (ic)) ||
2349 getSize (operandType (IC_RESULT (ic))) > 1))
2352 if (ic->op == LEFT_OP &&
2353 (isOperandLiteral (IC_RIGHT (ic)) ||
2354 getSize (operandType (IC_RESULT (ic))) > 1))
2357 if (IS_BITWISE_OP (ic) &&
2358 getSize (operandType (IC_RESULT (ic))) > 1)
2362 /* has only one definition */
2363 if (bitVectnBitsOn (OP_DEFS (IC_RESULT (ic))) > 1)
2366 /* has only one use */
2367 if (bitVectnBitsOn (OP_USES (IC_RESULT (ic))) > 1)
2370 /* and the usage immediately follows this iCode */
2371 if (!(uic = hTabItemWithKey (iCodehTab,
2372 bitVectFirstBit (OP_USES (IC_RESULT (ic))))))
2375 if (ic->next != uic)
2378 /* if it is a conditional branch then we definitely can */
2382 if (uic->op == JUMPTABLE)
2385 if (POINTER_SET (uic) &&
2386 getSize (aggrToPtr (operandType (IC_RESULT (uic)), FALSE)) > 1)
2389 /* if the usage is not is an assignment
2390 or an arithmetic / bitwise / shift operation then not */
2391 if (uic->op != '=' &&
2392 !IS_ARITHMETIC_OP (uic) &&
2393 !IS_BITWISE_OP (uic) &&
2394 uic->op != LEFT_OP &&
2395 uic->op != RIGHT_OP)
2398 /* if used in ^ operation then make sure right is not a
2399 literal (WIML: Why is this?) */
2400 if (uic->op == '^' && isOperandLiteral (IC_RIGHT (uic)))
2403 /* if shift operation make sure right side is not a literal */
2404 /* WIML: Why is this? */
2405 if (uic->op == RIGHT_OP &&
2406 (isOperandLiteral (IC_RIGHT (uic)) ||
2407 getSize (operandType (IC_RESULT (uic))) > 1))
2409 if (uic->op == LEFT_OP &&
2410 (isOperandLiteral (IC_RIGHT (uic)) ||
2411 getSize (operandType (IC_RESULT (uic))) > 1))
2414 /* make sure that the result of this icode is not on the
2415 stack, since acc is used to compute stack offset */
2417 if (IS_TRUE_SYMOP (IC_RESULT (uic)) &&
2418 OP_SYMBOL (IC_RESULT (uic))->onStack)
2421 if (isOperandOnStack(IC_RESULT(uic)))
2425 /* if the usage has only one operand then we can */
2426 if (IC_LEFT (uic) == NULL ||
2427 IC_RIGHT (uic) == NULL)
2430 /* if the other operand uses the accumulator then we cannot */
2431 if ( (IC_LEFT(uic)->key == IC_RESULT(ic)->key &&
2432 operandUsesAcc(IC_RIGHT(uic))) ||
2433 (IC_RIGHT(uic)->key == IC_RESULT(ic)->key &&
2434 operandUsesAcc(IC_LEFT(uic))) )
2437 /* make sure this is on the left side if not commutative */
2438 /* except for '-', which has been written to be able to
2439 handle reversed operands */
2440 if (!(isCommutativeOp(ic->op) || ic->op == '-') &&
2441 IC_LEFT (uic)->key != IC_RESULT (ic)->key)
2445 // this is too dangerous and need further restrictions
2448 /* if one of them is a literal then we can */
2449 if ((IC_LEFT (uic) && IS_OP_LITERAL (IC_LEFT (uic))) ||
2450 (IC_RIGHT (uic) && IS_OP_LITERAL (IC_RIGHT (uic))))
2452 OP_SYMBOL (IC_RESULT (ic))->accuse = 1;
2458 OP_SYMBOL (IC_RESULT (ic))->accuse = 1;
2462 /*-----------------------------------------------------------------*/
2463 /* packForPush - hueristics to reduce iCode for pushing */
2464 /*-----------------------------------------------------------------*/
2466 packForPush (iCode * ic, eBBlock ** ebpp, int blockno)
2470 struct eBBlock * ebp=ebpp[blockno];
2472 if (ic->op != IPUSH || !IS_ITEMP (IC_LEFT (ic)))
2475 /* must have only definition & one usage */
2476 if (bitVectnBitsOn (OP_DEFS (IC_LEFT (ic))) != 1 ||
2477 bitVectnBitsOn (OP_USES (IC_LEFT (ic))) != 1)
2480 /* find the definition */
2481 if (!(dic = hTabItemWithKey (iCodehTab,
2482 bitVectFirstBit (OP_DEFS (IC_LEFT (ic))))))
2485 if (dic->op != '=' || POINTER_SET (dic))
2488 if (dic->seq < ebp->fSeq) { // Evelyn did this
2490 for (i=0; i<blockno; i++) {
2491 if (dic->seq >= ebpp[i]->fSeq && dic->seq <= ebpp[i]->lSeq) {
2496 wassert (i!=blockno); // no way to recover from here
2499 if (IS_SYMOP(IC_RIGHT(dic))) {
2500 /* make sure the right side does not have any definitions
2502 dbv = OP_DEFS(IC_RIGHT(dic));
2503 for (lic = ic; lic && lic != dic ; lic = lic->prev) {
2504 if (bitVectBitValue(dbv,lic->key))
2507 /* make sure they have the same type */
2509 sym_link *itype=operandType(IC_LEFT(ic));
2510 sym_link *ditype=operandType(IC_RIGHT(dic));
2512 if (SPEC_USIGN(itype)!=SPEC_USIGN(ditype) ||
2513 SPEC_LONG(itype)!=SPEC_LONG(ditype))
2516 /* extend the live range of replaced operand if needed */
2517 if (OP_SYMBOL(IC_RIGHT(dic))->liveTo < ic->seq) {
2518 OP_SYMBOL(IC_RIGHT(dic))->liveTo = ic->seq;
2520 bitVectUnSetBit(OP_SYMBOL(IC_RESULT(dic))->defs,dic->key);
2523 /* we now we know that it has one & only one def & use
2524 and the that the definition is an assignment */
2525 ReplaceOpWithCheaperOp(&IC_LEFT (ic), IC_RIGHT (dic));
2526 remiCodeFromeBBlock (ebp, dic);
2527 hTabDeleteItem (&iCodehTab, dic->key, dic, DELETE_ITEM, NULL);
2530 /*-----------------------------------------------------------------*/
2531 /* packRegisters - does some transformations to reduce register */
2533 /*-----------------------------------------------------------------*/
2535 packRegisters (eBBlock ** ebpp, int blockno)
2539 eBBlock *ebp=ebpp[blockno];
2546 /* look for assignments of the form */
2547 /* iTempNN = TRueSym (someoperation) SomeOperand */
2549 /* TrueSym := iTempNN:1 */
2550 for (ic = ebp->sch; ic; ic = ic->next)
2552 /* find assignment of the form TrueSym := iTempNN:1 */
2553 if (ic->op == '=' && !POINTER_SET (ic))
2554 change += packRegsForAssign (ic, ebp);
2561 for (ic = ebp->sch; ic; ic = ic->next)
2563 /* if this is an itemp & result of an address of a true sym
2564 then mark this as rematerialisable */
2565 if (ic->op == ADDRESS_OF &&
2566 IS_ITEMP (IC_RESULT (ic)) &&
2567 IS_TRUE_SYMOP (IC_LEFT (ic)) &&
2568 bitVectnBitsOn (OP_DEFS (IC_RESULT (ic))) == 1 &&
2569 !OP_SYMBOL (IC_LEFT (ic))->onStack)
2572 OP_SYMBOL (IC_RESULT (ic))->remat = 1;
2573 OP_SYMBOL (IC_RESULT (ic))->rematiCode = ic;
2574 OP_SYMBOL (IC_RESULT (ic))->usl.spillLoc = NULL;
2578 /* if straight assignment then carry remat flag if
2579 this is the only definition */
2580 if (ic->op == '=' &&
2581 !POINTER_SET (ic) &&
2582 IS_SYMOP (IC_RIGHT (ic)) &&
2583 OP_SYMBOL (IC_RIGHT (ic))->remat &&
2584 !IS_CAST_ICODE(OP_SYMBOL (IC_RIGHT (ic))->rematiCode) &&
2585 bitVectnBitsOn (OP_SYMBOL (IC_RESULT (ic))->defs) <= 1)
2588 OP_SYMBOL (IC_RESULT (ic))->remat =
2589 OP_SYMBOL (IC_RIGHT (ic))->remat;
2590 OP_SYMBOL (IC_RESULT (ic))->rematiCode =
2591 OP_SYMBOL (IC_RIGHT (ic))->rematiCode;
2594 /* if cast to a generic pointer & the pointer being
2595 cast is remat, then we can remat this cast as well */
2596 if (ic->op == CAST &&
2597 IS_SYMOP(IC_RIGHT(ic)) &&
2598 OP_SYMBOL(IC_RIGHT(ic))->remat ) {
2599 sym_link *to_type = operandType(IC_LEFT(ic));
2600 sym_link *from_type = operandType(IC_RIGHT(ic));
2601 if (IS_GENPTR(to_type) && IS_PTR(from_type)) {
2602 OP_SYMBOL (IC_RESULT (ic))->remat = 1;
2603 OP_SYMBOL (IC_RESULT (ic))->rematiCode = ic;
2604 OP_SYMBOL (IC_RESULT (ic))->usl.spillLoc = NULL;
2608 /* if this is a +/- operation with a rematerizable
2609 then mark this as rematerializable as well */
2610 if ((ic->op == '+' || ic->op == '-') &&
2611 (IS_SYMOP (IC_LEFT (ic)) &&
2612 IS_ITEMP (IC_RESULT (ic)) &&
2613 IS_OP_LITERAL (IC_RIGHT (ic))) &&
2614 OP_SYMBOL (IC_LEFT (ic))->remat &&
2615 (!IS_SYMOP (IC_RIGHT (ic)) || !IS_CAST_ICODE(OP_SYMBOL (IC_RIGHT (ic))->rematiCode)) &&
2616 bitVectnBitsOn (OP_DEFS (IC_RESULT (ic))) == 1)
2618 OP_SYMBOL (IC_RESULT (ic))->remat = 1;
2619 OP_SYMBOL (IC_RESULT (ic))->rematiCode = ic;
2620 OP_SYMBOL (IC_RESULT (ic))->usl.spillLoc = NULL;
2623 /* mark the pointer usages */
2624 if (POINTER_SET (ic))
2625 OP_SYMBOL (IC_RESULT (ic))->uptr = 1;
2627 if (POINTER_GET (ic))
2628 OP_SYMBOL (IC_LEFT (ic))->uptr = 1;
2632 /* if we are using a symbol on the stack
2633 then we should say mcs51_ptrRegReq */
2634 if (ic->op == IFX && IS_SYMOP (IC_COND (ic)))
2635 mcs51_ptrRegReq += ((OP_SYMBOL (IC_COND (ic))->onStack ||
2636 OP_SYMBOL (IC_COND (ic))->iaccess) ? 1 : 0);
2637 else if (ic->op == JUMPTABLE && IS_SYMOP (IC_JTCOND (ic)))
2638 mcs51_ptrRegReq += ((OP_SYMBOL (IC_JTCOND (ic))->onStack ||
2639 OP_SYMBOL (IC_JTCOND (ic))->iaccess) ? 1 : 0);
2642 if (IS_SYMOP (IC_LEFT (ic)))
2643 mcs51_ptrRegReq += ((OP_SYMBOL (IC_LEFT (ic))->onStack ||
2644 OP_SYMBOL (IC_LEFT (ic))->iaccess) ? 1 : 0);
2645 if (IS_SYMOP (IC_RIGHT (ic)))
2646 mcs51_ptrRegReq += ((OP_SYMBOL (IC_RIGHT (ic))->onStack ||
2647 OP_SYMBOL (IC_RIGHT (ic))->iaccess) ? 1 : 0);
2648 if (IS_SYMOP (IC_RESULT (ic)))
2649 mcs51_ptrRegReq += ((OP_SYMBOL (IC_RESULT (ic))->onStack ||
2650 OP_SYMBOL (IC_RESULT (ic))->iaccess) ? 1 : 0);
2654 /* if the condition of an if instruction
2655 is defined in the previous instruction and
2656 this is the only usage then
2657 mark the itemp as a conditional */
2658 if ((IS_CONDITIONAL (ic) ||
2659 (IS_BITWISE_OP(ic) && isBitwiseOptimizable (ic))) &&
2660 ic->next && ic->next->op == IFX &&
2661 bitVectnBitsOn (OP_USES(IC_RESULT(ic)))==1 &&
2662 isOperandEqual (IC_RESULT (ic), IC_COND (ic->next)) &&
2663 OP_SYMBOL (IC_RESULT (ic))->liveTo <= ic->next->seq)
2665 OP_SYMBOL (IC_RESULT (ic))->regType = REG_CND;
2669 /* reduce for support function calls */
2670 if (ic->supportRtn || ic->op == '+' || ic->op == '-')
2671 packRegsForSupport (ic, ebp);
2673 /* some cases the redundant moves can
2674 can be eliminated for return statements */
2675 if ((ic->op == RETURN || (ic->op == SEND && ic->argreg == 1)) &&
2676 !isOperandInFarSpace (IC_LEFT (ic)) &&
2677 options.model == MODEL_SMALL) {
2678 packRegsForOneuse (ic, IC_LEFT (ic), ebp);
2681 /* if pointer set & left has a size more than
2682 one and right is not in far space */
2683 if (POINTER_SET (ic) &&
2684 !isOperandInFarSpace (IC_RIGHT (ic)) &&
2685 !OP_SYMBOL (IC_RESULT (ic))->remat &&
2686 !IS_OP_RUONLY (IC_RIGHT (ic)) &&
2687 getSize (aggrToPtr (operandType (IC_RESULT (ic)), FALSE)) > 1)
2688 packRegsForOneuse (ic, IC_RESULT (ic), ebp);
2690 /* if pointer get */
2691 if (POINTER_GET (ic) &&
2692 !isOperandInFarSpace (IC_RESULT (ic)) &&
2693 !OP_SYMBOL (IC_LEFT (ic))->remat &&
2694 !IS_OP_RUONLY (IC_RESULT (ic)) &&
2695 getSize (aggrToPtr (operandType (IC_LEFT (ic)), FALSE)) > 1)
2696 packRegsForOneuse (ic, IC_LEFT (ic), ebp);
2699 /* if this is cast for intergral promotion then
2700 check if only use of the definition of the
2701 operand being casted/ if yes then replace
2702 the result of that arithmetic operation with
2703 this result and get rid of the cast */
2706 sym_link *fromType = operandType (IC_RIGHT (ic));
2707 sym_link *toType = operandType (IC_LEFT (ic));
2709 if (IS_INTEGRAL (fromType) && IS_INTEGRAL (toType) &&
2710 getSize (fromType) != getSize (toType) &&
2711 SPEC_USIGN (fromType) == SPEC_USIGN (toType))
2714 iCode *dic = packRegsForOneuse (ic, IC_RIGHT (ic), ebp);
2717 if (IS_ARITHMETIC_OP (dic))
2719 bitVectUnSetBit(OP_SYMBOL(IC_RESULT(dic))->defs,dic->key);
2720 ReplaceOpWithCheaperOp(&IC_RESULT (dic), IC_RESULT (ic));
2721 remiCodeFromeBBlock (ebp, ic);
2722 bitVectUnSetBit(OP_SYMBOL(IC_RESULT(ic))->defs,ic->key);
2723 hTabDeleteItem (&iCodehTab, ic->key, ic, DELETE_ITEM, NULL);
2724 OP_DEFS_SET ((IC_RESULT (dic)), bitVectSetBit (OP_DEFS (IC_RESULT (dic)), dic->key));
2728 OP_SYMBOL (IC_RIGHT (ic))->ruonly = 0;
2734 /* if the type from and type to are the same
2735 then if this is the only use then packit */
2736 if (compareType (operandType (IC_RIGHT (ic)),
2737 operandType (IC_LEFT (ic))) == 1)
2739 iCode *dic = packRegsForOneuse (ic, IC_RIGHT (ic), ebp);
2742 bitVectUnSetBit(OP_SYMBOL(IC_RESULT(dic))->defs,dic->key);
2743 ReplaceOpWithCheaperOp(&IC_RESULT (dic), IC_RESULT (ic));
2744 remiCodeFromeBBlock (ebp, ic);
2745 bitVectUnSetBit(OP_SYMBOL(IC_RESULT(ic))->defs,ic->key);
2746 hTabDeleteItem (&iCodehTab, ic->key, ic, DELETE_ITEM, NULL);
2747 OP_DEFS_SET ((IC_RESULT (dic)), bitVectSetBit (OP_DEFS (IC_RESULT (dic)), dic->key));
2755 iTempNN := (some variable in farspace) V1
2760 if (ic->op == IPUSH)
2762 packForPush (ic, ebpp, blockno);
2766 /* pack registers for accumulator use, when the
2767 result of an arithmetic or bit wise operation
2768 has only one use, that use is immediately following
2769 the defintion and the using iCode has only one
2770 operand or has two operands but one is literal &
2771 the result of that operation is not on stack then
2772 we can leave the result of this operation in acc:b
2774 if ((IS_ARITHMETIC_OP (ic)
2775 || IS_CONDITIONAL(ic)
2776 || IS_BITWISE_OP (ic)
2777 || ic->op == LEFT_OP || ic->op == RIGHT_OP || ic->op == CALL
2778 || (ic->op == ADDRESS_OF && isOperandOnStack (IC_LEFT (ic)))
2780 IS_ITEMP (IC_RESULT (ic)) &&
2781 getSize (operandType (IC_RESULT (ic))) <= 2)
2783 packRegsForAccUse (ic);
2787 /*-----------------------------------------------------------------*/
2788 /* assignRegisters - assigns registers to each live range as need */
2789 /*-----------------------------------------------------------------*/
2791 mcs51_assignRegisters (eBBlock ** ebbs, int count)
2796 setToNull ((void *) &_G.funcrUsed);
2797 setToNull ((void *) &_G.totRegAssigned);
2798 mcs51_ptrRegReq = _G.stackExtend = _G.dataExtend = 0;
2801 /* change assignments this will remove some
2802 live ranges reducing some register pressure */
2803 for (i = 0; i < count; i++)
2804 packRegisters (ebbs, i);
2806 if (options.dump_pack)
2807 dumpEbbsToFileExt (DUMP_PACK, ebbs, count);
2809 /* first determine for each live range the number of
2810 registers & the type of registers required for each */
2813 /* and serially allocate registers */
2814 serialRegAssign (ebbs, count);
2819 /* if stack was extended then tell the user */
2822 /* werror(W_TOOMANY_SPILS,"stack", */
2823 /* _G.stackExtend,currFunc->name,""); */
2829 /* werror(W_TOOMANY_SPILS,"data space", */
2830 /* _G.dataExtend,currFunc->name,""); */
2834 /* after that create the register mask
2835 for each of the instruction */
2836 createRegMask (ebbs, count);
2838 /* redo that offsets for stacked automatic variables */
2839 redoStackOffsets ();
2841 if (options.dump_rassgn)
2843 dumpEbbsToFileExt (DUMP_RASSGN, ebbs, count);
2844 dumpLiveRanges (DUMP_LRANGE, liveRanges);
2847 /* do the overlaysegment stuff SDCCmem.c */
2848 doOverlays (ebbs, count);
2850 /* now get back the chain */
2851 ic = iCodeLabelOptimize (iCodeFromeBBlock (ebbs, count));
2855 /* free up any _G.stackSpil locations allocated */
2856 applyToSet (_G.stackSpil, deallocStackSpil);
2858 setToNull ((void **) &_G.stackSpil);
2859 setToNull ((void **) &_G.spiltSet);
2860 /* mark all registers as free */