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 it has a spillocation & is used less than
1179 all other live ranges then spill this */
1181 if (sym->usl.spillLoc) {
1182 symbol *leastUsed = leastUsedLR (liveRangesWith (spillable,
1183 allLRs, ebbs[i], ic));
1184 if (leastUsed && leastUsed->used > sym->used) {
1189 /* if none of the liveRanges have a spillLocation then better
1190 to spill this one than anything else already assigned to registers */
1191 if (liveRangesWith(spillable,noSpilLoc,ebbs[i],ic)) {
1192 /* if this is local to this block then we might find a block spil */
1193 if (!(sym->liveFrom >= ebbs[i]->fSeq && sym->liveTo <= ebbs[i]->lSeq)) {
1200 /* if we need ptr regs for the right side
1202 if (POINTER_GET (ic) && IS_SYMOP (IC_LEFT (ic))
1203 && getSize (OP_SYMBOL (IC_LEFT (ic))->type) <= (unsigned int) PTRSIZE) {
1207 /* else we assign registers to it */
1208 _G.regAssigned = bitVectSetBit (_G.regAssigned, sym->key);
1209 _G.totRegAssigned = bitVectSetBit (_G.totRegAssigned, sym->key);
1211 for (j = 0; j < sym->nRegs; j++) {
1212 if (sym->regType == REG_PTR)
1213 sym->regs[j] = getRegPtr (ic, ebbs[i], sym);
1215 sym->regs[j] = getRegGpr (ic, ebbs[i], sym);
1217 /* if the allocation failed which means
1218 this was spilt then break */
1219 if (!sym->regs[j]) {
1224 /* if it shares registers with operands make sure
1225 that they are in the same position */
1226 if (IC_LEFT (ic) && IS_SYMOP (IC_LEFT (ic)) &&
1227 OP_SYMBOL (IC_LEFT (ic))->nRegs && ic->op != '=') {
1228 positionRegs (OP_SYMBOL (IC_RESULT (ic)),
1229 OP_SYMBOL (IC_LEFT (ic)));
1231 /* do the same for the right operand */
1232 if (IC_RIGHT (ic) && IS_SYMOP (IC_RIGHT (ic)) &&
1233 OP_SYMBOL (IC_RIGHT (ic))->nRegs) {
1234 positionRegs (OP_SYMBOL (IC_RESULT (ic)),
1235 OP_SYMBOL (IC_RIGHT (ic)));
1248 /*-----------------------------------------------------------------*/
1249 /* fillGaps - Try to fill in the Gaps left by Pass1 */
1250 /*-----------------------------------------------------------------*/
1251 static void fillGaps()
1256 if (getenv("DISABLE_FILL_GAPS")) return;
1258 /* look for livernages that was spilt by the allocator */
1259 for (sym = hTabFirstItem(liveRanges,&key) ; sym ;
1260 sym = hTabNextItem(liveRanges,&key)) {
1265 if (!sym->spillA || !sym->clashes || sym->remat) continue ;
1267 /* find the liveRanges this one clashes with, that are
1268 still assigned to registers & mark the registers as used*/
1269 for ( i = 0 ; i < sym->clashes->size ; i ++) {
1273 if (bitVectBitValue(sym->clashes,i) == 0 || /* those that clash with this */
1274 bitVectBitValue(_G.totRegAssigned,i) == 0) /* and are still assigned to registers */
1277 clr = hTabItemWithKey(liveRanges,i);
1280 /* mark these registers as used */
1281 for (k = 0 ; k < clr->nRegs ; k++ )
1282 useReg(clr->regs[k]);
1285 if (willCauseSpill(sym->nRegs,sym->regType)) {
1286 /* NOPE :( clear all registers & and continue */
1291 /* THERE IS HOPE !!!! */
1292 for (i=0; i < sym->nRegs ; i++ ) {
1293 if (sym->regType == REG_PTR)
1294 sym->regs[i] = getRegPtrNoSpil ();
1296 sym->regs[i] = getRegGprNoSpil ();
1299 /* for all its definitions check if the registers
1300 allocated needs positioning NOTE: we can position
1301 only ONCE if more than One positioning required
1304 for (i = 0 ; i < sym->defs->size ; i++ ) {
1305 if (bitVectBitValue(sym->defs,i)) {
1307 if (!(ic = hTabItemWithKey(iCodehTab,i))) continue ;
1308 if (SKIP_IC(ic)) continue;
1309 assert(isSymbolEqual(sym,OP_SYMBOL(IC_RESULT(ic)))); /* just making sure */
1310 /* if left is assigned to registers */
1311 if (IS_SYMOP(IC_LEFT(ic)) &&
1312 bitVectBitValue(_G.totRegAssigned,OP_SYMBOL(IC_LEFT(ic))->key)) {
1313 pdone += positionRegs(sym,OP_SYMBOL(IC_LEFT(ic)));
1315 if (IS_SYMOP(IC_RIGHT(ic)) &&
1316 bitVectBitValue(_G.totRegAssigned,OP_SYMBOL(IC_RIGHT(ic))->key)) {
1317 pdone += positionRegs(sym,OP_SYMBOL(IC_RIGHT(ic)));
1319 if (pdone > 1) break;
1322 for (i = 0 ; i < sym->uses->size ; i++ ) {
1323 if (bitVectBitValue(sym->uses,i)) {
1325 if (!(ic = hTabItemWithKey(iCodehTab,i))) continue ;
1326 if (SKIP_IC(ic)) continue;
1327 if (!IS_ASSIGN_ICODE(ic)) continue ;
1329 /* if result is assigned to registers */
1330 if (IS_SYMOP(IC_RESULT(ic)) &&
1331 bitVectBitValue(_G.totRegAssigned,OP_SYMBOL(IC_RESULT(ic))->key)) {
1332 pdone += positionRegs(sym,OP_SYMBOL(IC_RESULT(ic)));
1334 if (pdone > 1) break;
1337 /* had to position more than once GIVE UP */
1339 /* UNDO all the changes we made to try this */
1341 for (i=0; i < sym->nRegs ; i++ ) {
1342 sym->regs[i] = NULL;
1345 D(printf ("Fill Gap gave up due to positioning for %s in function %s\n",sym->name, currFunc ? currFunc->name : "UNKNOWN"));
1348 D(printf ("FILLED GAP for %s in function %s\n",sym->name, currFunc ? currFunc->name : "UNKNOWN"));
1349 _G.totRegAssigned = bitVectSetBit(_G.totRegAssigned,sym->key);
1350 sym->isspilt = sym->spillA = 0 ;
1351 sym->usl.spillLoc->allocreq--;
1356 /*-----------------------------------------------------------------*/
1357 /* rUmaskForOp :- returns register mask for an operand */
1358 /*-----------------------------------------------------------------*/
1360 mcs51_rUmaskForOp (operand * op)
1366 /* only temporaries are assigned registers */
1370 sym = OP_SYMBOL (op);
1372 /* if spilt or no registers assigned to it
1374 if (sym->isspilt || !sym->nRegs)
1377 rumask = newBitVect (mcs51_nRegs);
1379 for (j = 0; j < sym->nRegs; j++)
1381 rumask = bitVectSetBit (rumask,
1382 sym->regs[j]->rIdx);
1388 /*-----------------------------------------------------------------*/
1389 /* regsUsedIniCode :- returns bit vector of registers used in iCode */
1390 /*-----------------------------------------------------------------*/
1392 regsUsedIniCode (iCode * ic)
1394 bitVect *rmask = newBitVect (mcs51_nRegs);
1396 /* do the special cases first */
1399 rmask = bitVectUnion (rmask,
1400 mcs51_rUmaskForOp (IC_COND (ic)));
1404 /* for the jumptable */
1405 if (ic->op == JUMPTABLE)
1407 rmask = bitVectUnion (rmask,
1408 mcs51_rUmaskForOp (IC_JTCOND (ic)));
1413 /* of all other cases */
1415 rmask = bitVectUnion (rmask,
1416 mcs51_rUmaskForOp (IC_LEFT (ic)));
1420 rmask = bitVectUnion (rmask,
1421 mcs51_rUmaskForOp (IC_RIGHT (ic)));
1424 rmask = bitVectUnion (rmask,
1425 mcs51_rUmaskForOp (IC_RESULT (ic)));
1431 /*-----------------------------------------------------------------*/
1432 /* createRegMask - for each instruction will determine the regsUsed */
1433 /*-----------------------------------------------------------------*/
1435 createRegMask (eBBlock ** ebbs, int count)
1439 /* for all blocks */
1440 for (i = 0; i < count; i++)
1444 if (ebbs[i]->noPath &&
1445 (ebbs[i]->entryLabel != entryLabel &&
1446 ebbs[i]->entryLabel != returnLabel))
1449 /* for all instructions */
1450 for (ic = ebbs[i]->sch; ic; ic = ic->next)
1455 if (SKIP_IC2 (ic) || !ic->rlive)
1458 /* first mark the registers used in this
1460 ic->rUsed = regsUsedIniCode (ic);
1461 _G.funcrUsed = bitVectUnion (_G.funcrUsed, ic->rUsed);
1463 /* now create the register mask for those
1464 registers that are in use : this is a
1465 super set of ic->rUsed */
1466 ic->rMask = newBitVect (mcs51_nRegs + 1);
1468 /* for all live Ranges alive at this point */
1469 for (j = 1; j < ic->rlive->size; j++)
1474 /* if not alive then continue */
1475 if (!bitVectBitValue (ic->rlive, j))
1478 /* find the live range we are interested in */
1479 if (!(sym = hTabItemWithKey (liveRanges, j)))
1481 werror (E_INTERNAL_ERROR, __FILE__, __LINE__,
1482 "createRegMask cannot find live range");
1483 fprintf(stderr, "\tmissing live range: key=%d\n", j);
1487 /* if no register assigned to it */
1488 if (!sym->nRegs || sym->isspilt)
1491 /* for all the registers allocated to it */
1492 for (k = 0; k < sym->nRegs; k++)
1495 bitVectSetBit (ic->rMask, sym->regs[k]->rIdx);
1501 /*-----------------------------------------------------------------*/
1502 /* rematStr - returns the rematerialized string for a remat var */
1503 /*-----------------------------------------------------------------*/
1505 rematStr (symbol * sym)
1508 iCode *ic = sym->rematiCode;
1513 /* if plus or minus print the right hand side */
1514 if (ic->op == '+' || ic->op == '-')
1516 sprintf (s, "0x%04x %c ", (int) operandLitValue (IC_RIGHT (ic)),
1519 ic = OP_SYMBOL (IC_LEFT (ic))->rematiCode;
1523 /* cast then continue */
1524 if (IS_CAST_ICODE(ic)) {
1525 ic = OP_SYMBOL (IC_RIGHT (ic))->rematiCode;
1528 /* we reached the end */
1529 sprintf (s, "%s", OP_SYMBOL (IC_LEFT (ic))->rname);
1536 /*-----------------------------------------------------------------*/
1537 /* regTypeNum - computes the type & number of registers required */
1538 /*-----------------------------------------------------------------*/
1540 regTypeNum (eBBlock *ebbs)
1546 /* for each live range do */
1547 for (sym = hTabFirstItem (liveRanges, &k); sym;
1548 sym = hTabNextItem (liveRanges, &k))
1551 /* if used zero times then no registers needed */
1552 if ((sym->liveTo - sym->liveFrom) == 0)
1556 /* if the live range is a temporary */
1560 /* if the type is marked as a conditional */
1561 if (sym->regType == REG_CND)
1564 /* if used in return only then we don't
1566 if (sym->ruonly || sym->accuse)
1568 if (IS_AGGREGATE (sym->type) || sym->isptr)
1569 sym->type = aggrToPtr (sym->type, FALSE);
1574 /* if this symbol has only one usage and that is an assignment
1575 to a ruonly, we don't need registers */
1576 // if this symbol has only one def
1577 if (bitVectnBitsOn (sym->defs)==1) {
1578 printf ("sym: %s has only one usage", sym->name);
1580 if ((ic = hTabItemWithKey (iCodehTab, bitVectFirstBit (sym->defs)))) {
1582 printf (" for a call ");
1583 // if this is only assigned to a ruonly
1584 if ((ic = hTabItemWithKey (iCodehTab, bitVectFirstBit (sym->defs)))) {
1586 if (OP_SYMBOL(IC_RESULT(ic))->ruonly) {
1587 printf("regTypeNum: %s assigned to %s\n", \
1588 sym->name, OP_SYMBOL(IC_RESULT(ic))->name);
1597 /* if the symbol has only one definition &
1598 that definition is a get_pointer */
1599 if (bitVectnBitsOn (sym->defs) == 1 &&
1600 (ic = hTabItemWithKey (iCodehTab,
1601 bitVectFirstBit (sym->defs))) &&
1604 !IS_BITVAR (sym->etype))
1608 /* and that pointer is remat in data space */
1609 if (OP_SYMBOL (IC_LEFT (ic))->remat &&
1610 !IS_CAST_ICODE(OP_SYMBOL (IC_LEFT (ic))->rematiCode) &&
1611 DCL_TYPE (aggrToPtr (operandType(IC_LEFT(ic)), FALSE)) == POINTER)
1613 /* create a psuedo symbol & force a spil */
1614 symbol *psym = newSymbol (rematStr (OP_SYMBOL (IC_LEFT (ic))), 1);
1615 psym->type = sym->type;
1616 psym->etype = sym->etype;
1617 strcpy (psym->rname, psym->name);
1619 sym->usl.spillLoc = psym;
1620 #if 0 // an alternative fix for bug #480076
1621 /* now this is a useless assignment to itself */
1622 remiCodeFromeBBlock (ebbs, ic);
1624 /* now this really is an assignment to itself, make it so;
1625 it will be optimized out later */
1627 ReplaceOpWithCheaperOp(&IC_RIGHT(ic), IC_RESULT(ic));
1633 /* if in data space or idata space then try to
1634 allocate pointer register */
1638 /* if not then we require registers */
1639 sym->nRegs = ((IS_AGGREGATE (sym->type) || sym->isptr) ?
1640 getSize (sym->type = aggrToPtr (sym->type, FALSE)) :
1641 getSize (sym->type));
1645 fprintf (stderr, "allocated more than 4 or 0 registers for type ");
1646 printTypeChain (sym->type, stderr);
1647 fprintf (stderr, "\n");
1650 /* determine the type of register required */
1651 if (sym->nRegs == 1 &&
1652 IS_PTR (sym->type) &&
1654 sym->regType = REG_PTR;
1656 sym->regType = REG_GPR;
1660 /* for the first run we don't provide */
1661 /* registers for true symbols we will */
1662 /* see how things go */
1668 /*-----------------------------------------------------------------*/
1669 /* freeAllRegs - mark all registers as free */
1670 /*-----------------------------------------------------------------*/
1676 for (i = 0; i < mcs51_nRegs; i++)
1677 regs8051[i].isFree = 1;
1680 /*-----------------------------------------------------------------*/
1681 /* deallocStackSpil - this will set the stack pointer back */
1682 /*-----------------------------------------------------------------*/
1684 DEFSETFUNC (deallocStackSpil)
1692 /*-----------------------------------------------------------------*/
1693 /* farSpacePackable - returns the packable icode for far variables */
1694 /*-----------------------------------------------------------------*/
1696 farSpacePackable (iCode * ic)
1700 /* go thru till we find a definition for the
1701 symbol on the right */
1702 for (dic = ic->prev; dic; dic = dic->prev)
1704 /* if the definition is a call then no */
1705 if ((dic->op == CALL || dic->op == PCALL) &&
1706 IC_RESULT (dic)->key == IC_RIGHT (ic)->key)
1711 /* if shift by unknown amount then not */
1712 if ((dic->op == LEFT_OP || dic->op == RIGHT_OP) &&
1713 IC_RESULT (dic)->key == IC_RIGHT (ic)->key)
1716 /* if pointer get and size > 1 */
1717 if (POINTER_GET (dic) &&
1718 getSize (aggrToPtr (operandType (IC_LEFT (dic)), FALSE)) > 1)
1721 if (POINTER_SET (dic) &&
1722 getSize (aggrToPtr (operandType (IC_RESULT (dic)), FALSE)) > 1)
1725 /* if any three is a true symbol in far space */
1726 if (IC_RESULT (dic) &&
1727 IS_TRUE_SYMOP (IC_RESULT (dic)) &&
1728 isOperandInFarSpace (IC_RESULT (dic)))
1731 if (IC_RIGHT (dic) &&
1732 IS_TRUE_SYMOP (IC_RIGHT (dic)) &&
1733 isOperandInFarSpace (IC_RIGHT (dic)) &&
1734 !isOperandEqual (IC_RIGHT (dic), IC_RESULT (ic)))
1737 if (IC_LEFT (dic) &&
1738 IS_TRUE_SYMOP (IC_LEFT (dic)) &&
1739 isOperandInFarSpace (IC_LEFT (dic)) &&
1740 !isOperandEqual (IC_LEFT (dic), IC_RESULT (ic)))
1743 if (isOperandEqual (IC_RIGHT (ic), IC_RESULT (dic)))
1745 if ((dic->op == LEFT_OP ||
1746 dic->op == RIGHT_OP ||
1748 IS_OP_LITERAL (IC_RIGHT (dic)))
1758 /*-----------------------------------------------------------------*/
1759 /* packRegsForAssign - register reduction for assignment */
1760 /*-----------------------------------------------------------------*/
1762 packRegsForAssign (iCode * ic, eBBlock * ebp)
1766 if (!IS_ITEMP (IC_RIGHT (ic)) ||
1767 OP_SYMBOL (IC_RIGHT (ic))->isind ||
1768 OP_LIVETO (IC_RIGHT (ic)) > ic->seq)
1774 /* if the true symbol is defined in far space or on stack
1775 then we should not since this will increase register pressure */
1776 if (isOperandInFarSpace(IC_RESULT(ic)) && !farSpacePackable(ic)) {
1780 /* find the definition of iTempNN scanning backwards if we find a
1781 a use of the true symbol in before we find the definition then
1783 for (dic = ic->prev; dic; dic = dic->prev)
1785 /* if there is a function call then don't pack it */
1786 if ((dic->op == CALL || dic->op == PCALL))
1795 if (IS_TRUE_SYMOP (IC_RESULT (dic)) &&
1796 IS_OP_VOLATILE (IC_RESULT (dic)))
1802 if (IS_SYMOP (IC_RESULT (dic)) &&
1803 IC_RESULT (dic)->key == IC_RIGHT (ic)->key)
1805 if (POINTER_SET (dic))
1811 if (IS_SYMOP (IC_RIGHT (dic)) &&
1812 (IC_RIGHT (dic)->key == IC_RESULT (ic)->key ||
1813 IC_RIGHT (dic)->key == IC_RIGHT (ic)->key))
1819 if (IS_SYMOP (IC_LEFT (dic)) &&
1820 (IC_LEFT (dic)->key == IC_RESULT (ic)->key ||
1821 IC_LEFT (dic)->key == IC_RIGHT (ic)->key))
1827 if (POINTER_SET (dic) &&
1828 IC_RESULT (dic)->key == IC_RESULT (ic)->key)
1836 return 0; /* did not find */
1838 /* if assignment then check that right is not a bit */
1839 if (ASSIGNMENT (dic) && !POINTER_SET (dic))
1841 sym_link *etype = operandType (IC_RIGHT (dic));
1842 if (IS_BITFIELD (etype))
1845 /* if the result is on stack or iaccess then it must be
1846 the same atleast one of the operands */
1847 if (OP_SYMBOL (IC_RESULT (ic))->onStack ||
1848 OP_SYMBOL (IC_RESULT (ic))->iaccess)
1851 /* the operation has only one symbol
1852 operator then we can pack */
1853 if ((IC_LEFT (dic) && !IS_SYMOP (IC_LEFT (dic))) ||
1854 (IC_RIGHT (dic) && !IS_SYMOP (IC_RIGHT (dic))))
1857 if (!((IC_LEFT (dic) &&
1858 IC_RESULT (ic)->key == IC_LEFT (dic)->key) ||
1860 IC_RESULT (ic)->key == IC_RIGHT (dic)->key)))
1864 /* found the definition */
1865 /* replace the result with the result of */
1866 /* this assignment and remove this assignment */
1867 bitVectUnSetBit(OP_SYMBOL(IC_RESULT(dic))->defs,dic->key);
1868 ReplaceOpWithCheaperOp(&IC_RESULT (dic), IC_RESULT (ic));
1870 if (IS_ITEMP (IC_RESULT (dic)) && OP_SYMBOL (IC_RESULT (dic))->liveFrom > dic->seq)
1872 OP_SYMBOL (IC_RESULT (dic))->liveFrom = dic->seq;
1874 // jwk: and the otherway around?
1876 /* delete from liverange table also
1877 delete from all the points inbetween and the new
1879 for (sic = dic; sic != ic; sic = sic->next)
1881 bitVectUnSetBit (sic->rlive, IC_RESULT (ic)->key);
1882 if (IS_ITEMP (IC_RESULT (dic)))
1883 bitVectSetBit (sic->rlive, IC_RESULT (dic)->key);
1886 remiCodeFromeBBlock (ebp, ic);
1887 bitVectUnSetBit(OP_SYMBOL(IC_RESULT(ic))->defs,ic->key);
1888 hTabDeleteItem (&iCodehTab, ic->key, ic, DELETE_ITEM, NULL);
1889 OP_DEFS_SET ((IC_RESULT (dic)), bitVectSetBit (OP_DEFS (IC_RESULT (dic)), dic->key));
1893 /*------------------------------------------------------------------*/
1894 /* findAssignToSym : scanning backwards looks for first assig found */
1895 /*------------------------------------------------------------------*/
1897 findAssignToSym (operand * op, iCode * ic)
1901 /* This routine is used to find sequences like
1903 ...; (intervening ops don't use iTempAA or modify FOO)
1904 blah = blah + iTempAA;
1906 and eliminate the use of iTempAA, freeing up its register for
1911 for (dic = ic->prev; dic; dic = dic->prev)
1914 /* if definition by assignment */
1915 if (dic->op == '=' &&
1916 !POINTER_SET (dic) &&
1917 IC_RESULT (dic)->key == op->key
1918 /* && IS_TRUE_SYMOP(IC_RIGHT(dic)) */
1920 break; /* found where this temp was defined */
1922 /* if we find an usage then we cannot delete it */
1923 if (IC_LEFT (dic) && IC_LEFT (dic)->key == op->key)
1926 if (IC_RIGHT (dic) && IC_RIGHT (dic)->key == op->key)
1929 if (POINTER_SET (dic) && IC_RESULT (dic)->key == op->key)
1934 return NULL; /* didn't find any assignment to op */
1936 LRH(printf ("findAssignToSym: %s\n", OP_SYMBOL(IC_RESULT(dic))->name));
1937 /* we are interested only if defined in far space */
1938 /* or in stack space in case of + & - */
1940 /* if assigned to a non-symbol then don't repack regs */
1941 if (!IS_SYMOP (IC_RIGHT (dic)))
1944 /* if the symbol is volatile then we should not */
1945 if (isOperandVolatile (IC_RIGHT (dic), TRUE))
1947 /* XXX TODO --- should we be passing FALSE to isOperandVolatile()?
1948 What does it mean for an iTemp to be volatile, anyway? Passing
1949 TRUE is more cautious but may prevent possible optimizations */
1951 /* if the symbol is in far space then we should not */
1952 if (isOperandInFarSpace (IC_RIGHT (dic)))
1955 /* for + & - operations make sure that
1956 if it is on the stack it is the same
1957 as one of the three operands */
1958 if ((ic->op == '+' || ic->op == '-') &&
1959 OP_SYMBOL (IC_RIGHT (dic))->onStack)
1962 if (IC_RESULT (ic)->key != IC_RIGHT (dic)->key &&
1963 IC_LEFT (ic)->key != IC_RIGHT (dic)->key &&
1964 IC_RIGHT (ic)->key != IC_RIGHT (dic)->key)
1968 /* now make sure that the right side of dic
1969 is not defined between ic & dic */
1972 iCode *sic = dic->next;
1974 for (; sic != ic; sic = sic->next)
1975 if (IC_RESULT (sic) &&
1976 IC_RESULT (sic)->key == IC_RIGHT (dic)->key)
1983 /*-----------------------------------------------------------------*/
1984 /* reassignAliasedSym - used by packRegsForSupport to replace */
1985 /* redundant iTemp with equivalent symbol */
1986 /*-----------------------------------------------------------------*/
1988 reassignAliasedSym (eBBlock *ebp, iCode *assignment, iCode *use, operand *op)
1991 unsigned oldSymKey, newSymKey;
1993 oldSymKey = op->key;
1994 newSymKey = IC_RIGHT(assignment)->key;
1996 /* only track live ranges of compiler-generated temporaries */
1997 if (!IS_ITEMP(IC_RIGHT(assignment)))
2000 /* update the live-value bitmaps */
2001 for (ic = assignment; ic != use; ic = ic->next) {
2002 bitVectUnSetBit (ic->rlive, oldSymKey);
2004 ic->rlive = bitVectSetBit (ic->rlive, newSymKey);
2007 /* update the sym of the used operand */
2008 OP_SYMBOL(op) = OP_SYMBOL(IC_RIGHT(assignment));
2009 op->key = OP_SYMBOL(op)->key;
2011 /* update the sym's liverange */
2012 if ( OP_LIVETO(op) < ic->seq )
2013 setToRange(op, ic->seq, FALSE);
2015 /* remove the assignment iCode now that its result is unused */
2016 remiCodeFromeBBlock (ebp, assignment);
2017 bitVectUnSetBit(OP_SYMBOL(IC_RESULT(assignment))->defs, assignment->key);
2018 hTabDeleteItem (&iCodehTab, assignment->key, assignment, DELETE_ITEM, NULL);
2022 /*-----------------------------------------------------------------*/
2023 /* packRegsForSupport :- reduce some registers for support calls */
2024 /*-----------------------------------------------------------------*/
2026 packRegsForSupport (iCode * ic, eBBlock * ebp)
2030 /* for the left & right operand :- look to see if the
2031 left was assigned a true symbol in far space in that
2032 case replace them */
2034 if (IS_ITEMP (IC_LEFT (ic)) &&
2035 OP_SYMBOL (IC_LEFT (ic))->liveTo <= ic->seq)
2037 dic = findAssignToSym (IC_LEFT (ic), ic);
2041 /* found it we need to remove it from the block */
2042 reassignAliasedSym (ebp, dic, ic, IC_LEFT(ic));
2047 /* do the same for the right operand */
2048 if (IS_ITEMP (IC_RIGHT (ic)) &&
2049 OP_SYMBOL (IC_RIGHT (ic))->liveTo <= ic->seq)
2051 iCode *dic = findAssignToSym (IC_RIGHT (ic), ic);
2055 /* if this is a subtraction & the result
2056 is a true symbol in far space then don't pack */
2057 if (ic->op == '-' && IS_TRUE_SYMOP (IC_RESULT (dic)))
2059 sym_link *etype = getSpec (operandType (IC_RESULT (dic)));
2060 if (IN_FARSPACE (SPEC_OCLS (etype)))
2063 /* found it we need to remove it from the
2065 reassignAliasedSym (ebp, dic, ic, IC_RIGHT(ic));
2074 #define IS_OP_RUONLY(x) (x && IS_SYMOP(x) && OP_SYMBOL(x)->ruonly)
2077 /*-----------------------------------------------------------------*/
2078 /* packRegsForOneuse : - will reduce some registers for single Use */
2079 /*-----------------------------------------------------------------*/
2081 packRegsForOneuse (iCode * ic, operand * op, eBBlock * ebp)
2086 /* if returning a literal then do nothing */
2090 /* only upto 2 bytes since we cannot predict
2091 the usage of b, & acc */
2092 if (getSize (operandType (op)) > (fReturnSizeMCS51 - 2))
2095 if (ic->op != RETURN &&
2097 !POINTER_SET (ic) &&
2101 if (ic->op == SEND && ic->argreg != 1) return NULL;
2103 /* this routine will mark the a symbol as used in one
2104 instruction use only && if the defintion is local
2105 (ie. within the basic block) && has only one definition &&
2106 that definiion is either a return value from a
2107 function or does not contain any variables in
2109 uses = bitVectCopy (OP_USES (op));
2110 bitVectUnSetBit (uses, ic->key); /* take away this iCode */
2111 if (!bitVectIsZero (uses)) /* has other uses */
2114 /* if it has only one defintion */
2115 if (bitVectnBitsOn (OP_DEFS (op)) > 1)
2116 return NULL; /* has more than one definition */
2118 /* get that definition */
2120 hTabItemWithKey (iCodehTab,
2121 bitVectFirstBit (OP_DEFS (op)))))
2124 LRH(printf ("packRegsForOneUse: %s\n", OP_SYMBOL(op)->name));
2125 /* if that only usage is a cast */
2126 if (dic->op == CAST) {
2127 /* to a bigger type */
2128 if (getSize(OP_SYM_TYPE(IC_RESULT(dic))) >
2129 getSize(OP_SYM_TYPE(IC_RIGHT(dic)))) {
2130 /* than we can not, since we cannot predict the usage of b & acc */
2135 /* found the definition now check if it is local */
2136 if (dic->seq < ebp->fSeq ||
2137 dic->seq > ebp->lSeq)
2138 return NULL; /* non-local */
2140 /* now check if it is the return from
2142 if (dic->op == CALL || dic->op == PCALL)
2144 if (ic->op != SEND && ic->op != RETURN &&
2145 !POINTER_SET(ic) && !POINTER_GET(ic))
2147 OP_SYMBOL (op)->ruonly = 1;
2154 /* otherwise check that the definition does
2155 not contain any symbols in far space */
2156 if (isOperandInFarSpace (IC_LEFT (dic)) ||
2157 isOperandInFarSpace (IC_RIGHT (dic)) ||
2158 IS_OP_RUONLY (IC_LEFT (ic)) ||
2159 IS_OP_RUONLY (IC_RIGHT (ic)))
2164 /* if pointer set then make sure the pointer
2166 if (POINTER_SET (dic) &&
2167 !IS_DATA_PTR (aggrToPtr (operandType (IC_RESULT (dic)), FALSE)))
2170 if (POINTER_GET (dic) &&
2171 !IS_DATA_PTR (aggrToPtr (operandType (IC_LEFT (dic)), FALSE)))
2176 /* also make sure the intervenening instructions
2177 don't have any thing in far space */
2178 for (dic = dic->next; dic && dic != ic && sic != ic; dic = dic->next)
2181 /* if there is an intervening function call then no */
2182 if (dic->op == CALL || dic->op == PCALL)
2184 /* if pointer set then make sure the pointer
2186 if (POINTER_SET (dic) &&
2187 !IS_DATA_PTR (aggrToPtr (operandType (IC_RESULT (dic)), FALSE)))
2190 if (POINTER_GET (dic) &&
2191 !IS_DATA_PTR (aggrToPtr (operandType (IC_LEFT (dic)), FALSE)))
2194 /* if address of & the result is remat the okay */
2195 if (dic->op == ADDRESS_OF &&
2196 OP_SYMBOL (IC_RESULT (dic))->remat)
2199 /* if operand has size of three or more & this
2200 operation is a '*','/' or '%' then 'b' may
2202 if ((dic->op == '%' || dic->op == '/' || dic->op == '*') &&
2203 getSize (operandType (op)) >= 3)
2206 /* if left or right or result is in far space */
2207 if (isOperandInFarSpace (IC_LEFT (dic)) ||
2208 isOperandInFarSpace (IC_RIGHT (dic)) ||
2209 isOperandInFarSpace (IC_RESULT (dic)) ||
2210 IS_OP_RUONLY (IC_LEFT (dic)) ||
2211 IS_OP_RUONLY (IC_RIGHT (dic)) ||
2212 IS_OP_RUONLY (IC_RESULT (dic)))
2216 /* if left or right or result is on stack */
2217 if (isOperandOnStack(IC_LEFT(dic)) ||
2218 isOperandOnStack(IC_RIGHT(dic)) ||
2219 isOperandOnStack(IC_RESULT(dic))) {
2224 OP_SYMBOL (op)->ruonly = 1;
2228 /*-----------------------------------------------------------------*/
2229 /* isBitwiseOptimizable - requirements of JEAN LOUIS VERN */
2230 /*-----------------------------------------------------------------*/
2232 isBitwiseOptimizable (iCode * ic)
2234 sym_link *ltype = getSpec (operandType (IC_LEFT (ic)));
2235 sym_link *rtype = getSpec (operandType (IC_RIGHT (ic)));
2237 /* bitwise operations are considered optimizable
2238 under the following conditions (Jean-Louis VERN)
2250 if (IS_LITERAL(rtype) ||
2251 (IS_BITVAR (ltype) && IN_BITSPACE (SPEC_OCLS (ltype))))
2257 /*-----------------------------------------------------------------*/
2258 /* isCommutativeOp - tests whether this op cares what order its */
2259 /* operands are in */
2260 /*-----------------------------------------------------------------*/
2261 bool isCommutativeOp(unsigned int op)
2263 if (op == '+' || op == '*' || op == EQ_OP ||
2264 op == '^' || op == '|' || op == BITWISEAND)
2270 /*-----------------------------------------------------------------*/
2271 /* operandUsesAcc - determines whether the code generated for this */
2272 /* operand will have to use the accumulator */
2273 /*-----------------------------------------------------------------*/
2274 bool operandUsesAcc(operand *op)
2280 symbol *sym = OP_SYMBOL(op);
2284 return TRUE; /* duh! */
2286 if (IN_STACK(sym->etype) || sym->onStack ||
2287 (SPIL_LOC(op) && SPIL_LOC(op)->onStack))
2288 return TRUE; /* acc is used to calc stack offset */
2293 sym = SPIL_LOC(op); /* if spilled, look at spill location */
2295 return FALSE; /* more checks? */
2299 symspace = SPEC_OCLS(sym->etype);
2301 if (sym->iaccess && symspace->paged)
2302 return TRUE; /* must fetch paged indirect sym via accumulator */
2304 if (IN_BITSPACE(symspace))
2305 return TRUE; /* fetching bit vars uses the accumulator */
2307 if (IN_FARSPACE(symspace) || IN_CODESPACE(symspace))
2308 return TRUE; /* fetched via accumulator and dptr */
2314 /*-----------------------------------------------------------------*/
2315 /* packRegsForAccUse - pack registers for acc use */
2316 /*-----------------------------------------------------------------*/
2318 packRegsForAccUse (iCode * ic)
2322 /* if this is an aggregate, e.g. a one byte char array */
2323 if (IS_AGGREGATE(operandType(IC_RESULT(ic)))) {
2327 /* if we are calling a reentrant function that has stack parameters */
2328 if (ic->op == CALL &&
2329 IFFUNC_ISREENT(operandType(IC_LEFT(ic))) &&
2330 FUNC_HASSTACKPARM(operandType(IC_LEFT(ic))))
2333 if (ic->op == PCALL &&
2334 IFFUNC_ISREENT(operandType(IC_LEFT(ic))->next) &&
2335 FUNC_HASSTACKPARM(operandType(IC_LEFT(ic))->next))
2338 /* if + or - then it has to be one byte result */
2339 if ((ic->op == '+' || ic->op == '-')
2340 && getSize (operandType (IC_RESULT (ic))) > 1)
2343 /* if shift operation make sure right side is not a literal */
2344 if (ic->op == RIGHT_OP &&
2345 (isOperandLiteral (IC_RIGHT (ic)) ||
2346 getSize (operandType (IC_RESULT (ic))) > 1))
2349 if (ic->op == LEFT_OP &&
2350 (isOperandLiteral (IC_RIGHT (ic)) ||
2351 getSize (operandType (IC_RESULT (ic))) > 1))
2354 if (IS_BITWISE_OP (ic) &&
2355 getSize (operandType (IC_RESULT (ic))) > 1)
2359 /* has only one definition */
2360 if (bitVectnBitsOn (OP_DEFS (IC_RESULT (ic))) > 1)
2363 /* has only one use */
2364 if (bitVectnBitsOn (OP_USES (IC_RESULT (ic))) > 1)
2367 /* and the usage immediately follows this iCode */
2368 if (!(uic = hTabItemWithKey (iCodehTab,
2369 bitVectFirstBit (OP_USES (IC_RESULT (ic))))))
2372 if (ic->next != uic)
2375 /* if it is a conditional branch then we definitely can */
2379 if (uic->op == JUMPTABLE)
2382 if (POINTER_SET (uic) &&
2383 getSize (aggrToPtr (operandType (IC_RESULT (uic)), FALSE)) > 1)
2386 /* if the usage is not is an assignment
2387 or an arithmetic / bitwise / shift operation then not */
2388 if (uic->op != '=' &&
2389 !IS_ARITHMETIC_OP (uic) &&
2390 !IS_BITWISE_OP (uic) &&
2391 uic->op != LEFT_OP &&
2392 uic->op != RIGHT_OP)
2395 /* if used in ^ operation then make sure right is not a
2396 literal (WIML: Why is this?) */
2397 if (uic->op == '^' && isOperandLiteral (IC_RIGHT (uic)))
2400 /* if shift operation make sure right side is not a literal */
2401 /* WIML: Why is this? */
2402 if (uic->op == RIGHT_OP &&
2403 (isOperandLiteral (IC_RIGHT (uic)) ||
2404 getSize (operandType (IC_RESULT (uic))) > 1))
2406 if (uic->op == LEFT_OP &&
2407 (isOperandLiteral (IC_RIGHT (uic)) ||
2408 getSize (operandType (IC_RESULT (uic))) > 1))
2411 /* make sure that the result of this icode is not on the
2412 stack, since acc is used to compute stack offset */
2414 if (IS_TRUE_SYMOP (IC_RESULT (uic)) &&
2415 OP_SYMBOL (IC_RESULT (uic))->onStack)
2418 if (isOperandOnStack(IC_RESULT(uic)))
2422 /* if the usage has only one operand then we can */
2423 if (IC_LEFT (uic) == NULL ||
2424 IC_RIGHT (uic) == NULL)
2427 /* if the other operand uses the accumulator then we cannot */
2428 if ( (IC_LEFT(uic)->key == IC_RESULT(ic)->key &&
2429 operandUsesAcc(IC_RIGHT(uic))) ||
2430 (IC_RIGHT(uic)->key == IC_RESULT(ic)->key &&
2431 operandUsesAcc(IC_LEFT(uic))) )
2434 /* make sure this is on the left side if not commutative */
2435 /* except for '-', which has been written to be able to
2436 handle reversed operands */
2437 if (!(isCommutativeOp(ic->op) || ic->op == '-') &&
2438 IC_LEFT (uic)->key != IC_RESULT (ic)->key)
2442 // this is too dangerous and need further restrictions
2445 /* if one of them is a literal then we can */
2446 if ((IC_LEFT (uic) && IS_OP_LITERAL (IC_LEFT (uic))) ||
2447 (IC_RIGHT (uic) && IS_OP_LITERAL (IC_RIGHT (uic))))
2449 OP_SYMBOL (IC_RESULT (ic))->accuse = 1;
2455 OP_SYMBOL (IC_RESULT (ic))->accuse = 1;
2459 /*-----------------------------------------------------------------*/
2460 /* packForPush - hueristics to reduce iCode for pushing */
2461 /*-----------------------------------------------------------------*/
2463 packForPush (iCode * ic, eBBlock ** ebpp, int blockno)
2467 struct eBBlock * ebp=ebpp[blockno];
2469 if (ic->op != IPUSH || !IS_ITEMP (IC_LEFT (ic)))
2472 /* must have only definition & one usage */
2473 if (bitVectnBitsOn (OP_DEFS (IC_LEFT (ic))) != 1 ||
2474 bitVectnBitsOn (OP_USES (IC_LEFT (ic))) != 1)
2477 /* find the definition */
2478 if (!(dic = hTabItemWithKey (iCodehTab,
2479 bitVectFirstBit (OP_DEFS (IC_LEFT (ic))))))
2482 if (dic->op != '=' || POINTER_SET (dic))
2485 if (dic->seq < ebp->fSeq) { // Evelyn did this
2487 for (i=0; i<blockno; i++) {
2488 if (dic->seq >= ebpp[i]->fSeq && dic->seq <= ebpp[i]->lSeq) {
2493 wassert (i!=blockno); // no way to recover from here
2496 if (IS_SYMOP(IC_RIGHT(dic))) {
2497 /* make sure the right side does not have any definitions
2499 dbv = OP_DEFS(IC_RIGHT(dic));
2500 for (lic = ic; lic && lic != dic ; lic = lic->prev) {
2501 if (bitVectBitValue(dbv,lic->key))
2504 /* make sure they have the same type */
2506 sym_link *itype=operandType(IC_LEFT(ic));
2507 sym_link *ditype=operandType(IC_RIGHT(dic));
2509 if (SPEC_USIGN(itype)!=SPEC_USIGN(ditype) ||
2510 SPEC_LONG(itype)!=SPEC_LONG(ditype))
2513 /* extend the live range of replaced operand if needed */
2514 if (OP_SYMBOL(IC_RIGHT(dic))->liveTo < ic->seq) {
2515 OP_SYMBOL(IC_RIGHT(dic))->liveTo = ic->seq;
2517 bitVectUnSetBit(OP_SYMBOL(IC_RESULT(dic))->defs,dic->key);
2520 /* we now we know that it has one & only one def & use
2521 and the that the definition is an assignment */
2522 ReplaceOpWithCheaperOp(&IC_LEFT (ic), IC_RIGHT (dic));
2523 remiCodeFromeBBlock (ebp, dic);
2524 hTabDeleteItem (&iCodehTab, dic->key, dic, DELETE_ITEM, NULL);
2527 /*-----------------------------------------------------------------*/
2528 /* packRegisters - does some transformations to reduce register */
2530 /*-----------------------------------------------------------------*/
2532 packRegisters (eBBlock ** ebpp, int blockno)
2536 eBBlock *ebp=ebpp[blockno];
2543 /* look for assignments of the form */
2544 /* iTempNN = TRueSym (someoperation) SomeOperand */
2546 /* TrueSym := iTempNN:1 */
2547 for (ic = ebp->sch; ic; ic = ic->next)
2549 /* find assignment of the form TrueSym := iTempNN:1 */
2550 if (ic->op == '=' && !POINTER_SET (ic))
2551 change += packRegsForAssign (ic, ebp);
2558 for (ic = ebp->sch; ic; ic = ic->next)
2560 /* if this is an itemp & result of an address of a true sym
2561 then mark this as rematerialisable */
2562 if (ic->op == ADDRESS_OF &&
2563 IS_ITEMP (IC_RESULT (ic)) &&
2564 IS_TRUE_SYMOP (IC_LEFT (ic)) &&
2565 bitVectnBitsOn (OP_DEFS (IC_RESULT (ic))) == 1 &&
2566 !OP_SYMBOL (IC_LEFT (ic))->onStack)
2569 OP_SYMBOL (IC_RESULT (ic))->remat = 1;
2570 OP_SYMBOL (IC_RESULT (ic))->rematiCode = ic;
2571 OP_SYMBOL (IC_RESULT (ic))->usl.spillLoc = NULL;
2575 /* if straight assignment then carry remat flag if
2576 this is the only definition */
2577 if (ic->op == '=' &&
2578 !POINTER_SET (ic) &&
2579 IS_SYMOP (IC_RIGHT (ic)) &&
2580 OP_SYMBOL (IC_RIGHT (ic))->remat &&
2581 !IS_CAST_ICODE(OP_SYMBOL (IC_RIGHT (ic))->rematiCode) &&
2582 bitVectnBitsOn (OP_SYMBOL (IC_RESULT (ic))->defs) <= 1)
2585 OP_SYMBOL (IC_RESULT (ic))->remat =
2586 OP_SYMBOL (IC_RIGHT (ic))->remat;
2587 OP_SYMBOL (IC_RESULT (ic))->rematiCode =
2588 OP_SYMBOL (IC_RIGHT (ic))->rematiCode;
2591 /* if cast to a generic pointer & the pointer being
2592 cast is remat, then we can remat this cast as well */
2593 if (ic->op == CAST &&
2594 IS_SYMOP(IC_RIGHT(ic)) &&
2595 OP_SYMBOL(IC_RIGHT(ic))->remat ) {
2596 sym_link *to_type = operandType(IC_LEFT(ic));
2597 sym_link *from_type = operandType(IC_RIGHT(ic));
2598 if (IS_GENPTR(to_type) && IS_PTR(from_type)) {
2599 OP_SYMBOL (IC_RESULT (ic))->remat = 1;
2600 OP_SYMBOL (IC_RESULT (ic))->rematiCode = ic;
2601 OP_SYMBOL (IC_RESULT (ic))->usl.spillLoc = NULL;
2605 /* if this is a +/- operation with a rematerizable
2606 then mark this as rematerializable as well */
2607 if ((ic->op == '+' || ic->op == '-') &&
2608 (IS_SYMOP (IC_LEFT (ic)) &&
2609 IS_ITEMP (IC_RESULT (ic)) &&
2610 IS_OP_LITERAL (IC_RIGHT (ic))) &&
2611 OP_SYMBOL (IC_LEFT (ic))->remat &&
2612 (!IS_SYMOP (IC_RIGHT (ic)) || !IS_CAST_ICODE(OP_SYMBOL (IC_RIGHT (ic))->rematiCode)) &&
2613 bitVectnBitsOn (OP_DEFS (IC_RESULT (ic))) == 1)
2615 OP_SYMBOL (IC_RESULT (ic))->remat = 1;
2616 OP_SYMBOL (IC_RESULT (ic))->rematiCode = ic;
2617 OP_SYMBOL (IC_RESULT (ic))->usl.spillLoc = NULL;
2620 /* mark the pointer usages */
2621 if (POINTER_SET (ic))
2622 OP_SYMBOL (IC_RESULT (ic))->uptr = 1;
2624 if (POINTER_GET (ic))
2625 OP_SYMBOL (IC_LEFT (ic))->uptr = 1;
2629 /* if we are using a symbol on the stack
2630 then we should say mcs51_ptrRegReq */
2631 if (ic->op == IFX && IS_SYMOP (IC_COND (ic)))
2632 mcs51_ptrRegReq += ((OP_SYMBOL (IC_COND (ic))->onStack ||
2633 OP_SYMBOL (IC_COND (ic))->iaccess) ? 1 : 0);
2634 else if (ic->op == JUMPTABLE && IS_SYMOP (IC_JTCOND (ic)))
2635 mcs51_ptrRegReq += ((OP_SYMBOL (IC_JTCOND (ic))->onStack ||
2636 OP_SYMBOL (IC_JTCOND (ic))->iaccess) ? 1 : 0);
2639 if (IS_SYMOP (IC_LEFT (ic)))
2640 mcs51_ptrRegReq += ((OP_SYMBOL (IC_LEFT (ic))->onStack ||
2641 OP_SYMBOL (IC_LEFT (ic))->iaccess) ? 1 : 0);
2642 if (IS_SYMOP (IC_RIGHT (ic)))
2643 mcs51_ptrRegReq += ((OP_SYMBOL (IC_RIGHT (ic))->onStack ||
2644 OP_SYMBOL (IC_RIGHT (ic))->iaccess) ? 1 : 0);
2645 if (IS_SYMOP (IC_RESULT (ic)))
2646 mcs51_ptrRegReq += ((OP_SYMBOL (IC_RESULT (ic))->onStack ||
2647 OP_SYMBOL (IC_RESULT (ic))->iaccess) ? 1 : 0);
2651 /* if the condition of an if instruction
2652 is defined in the previous instruction and
2653 this is the only usage then
2654 mark the itemp as a conditional */
2655 if ((IS_CONDITIONAL (ic) ||
2656 (IS_BITWISE_OP(ic) && isBitwiseOptimizable (ic))) &&
2657 ic->next && ic->next->op == IFX &&
2658 bitVectnBitsOn (OP_USES(IC_RESULT(ic)))==1 &&
2659 isOperandEqual (IC_RESULT (ic), IC_COND (ic->next)) &&
2660 OP_SYMBOL (IC_RESULT (ic))->liveTo <= ic->next->seq)
2662 OP_SYMBOL (IC_RESULT (ic))->regType = REG_CND;
2666 /* reduce for support function calls */
2667 if (ic->supportRtn || ic->op == '+' || ic->op == '-')
2668 packRegsForSupport (ic, ebp);
2670 /* some cases the redundant moves can
2671 can be eliminated for return statements */
2672 if ((ic->op == RETURN || (ic->op == SEND && ic->argreg == 1)) &&
2673 !isOperandInFarSpace (IC_LEFT (ic)) &&
2674 options.model == MODEL_SMALL) {
2675 packRegsForOneuse (ic, IC_LEFT (ic), ebp);
2678 /* if pointer set & left has a size more than
2679 one and right is not in far space */
2680 if (POINTER_SET (ic) &&
2681 !isOperandInFarSpace (IC_RIGHT (ic)) &&
2682 !OP_SYMBOL (IC_RESULT (ic))->remat &&
2683 !IS_OP_RUONLY (IC_RIGHT (ic)) &&
2684 getSize (aggrToPtr (operandType (IC_RESULT (ic)), FALSE)) > 1)
2685 packRegsForOneuse (ic, IC_RESULT (ic), ebp);
2687 /* if pointer get */
2688 if (POINTER_GET (ic) &&
2689 !isOperandInFarSpace (IC_RESULT (ic)) &&
2690 !OP_SYMBOL (IC_LEFT (ic))->remat &&
2691 !IS_OP_RUONLY (IC_RESULT (ic)) &&
2692 getSize (aggrToPtr (operandType (IC_LEFT (ic)), FALSE)) > 1)
2693 packRegsForOneuse (ic, IC_LEFT (ic), ebp);
2696 /* if this is cast for intergral promotion then
2697 check if only use of the definition of the
2698 operand being casted/ if yes then replace
2699 the result of that arithmetic operation with
2700 this result and get rid of the cast */
2703 sym_link *fromType = operandType (IC_RIGHT (ic));
2704 sym_link *toType = operandType (IC_LEFT (ic));
2706 if (IS_INTEGRAL (fromType) && IS_INTEGRAL (toType) &&
2707 getSize (fromType) != getSize (toType) &&
2708 SPEC_USIGN (fromType) == SPEC_USIGN (toType))
2711 iCode *dic = packRegsForOneuse (ic, IC_RIGHT (ic), ebp);
2714 if (IS_ARITHMETIC_OP (dic))
2716 bitVectUnSetBit(OP_SYMBOL(IC_RESULT(dic))->defs,dic->key);
2717 ReplaceOpWithCheaperOp(&IC_RESULT (dic), IC_RESULT (ic));
2718 remiCodeFromeBBlock (ebp, ic);
2719 bitVectUnSetBit(OP_SYMBOL(IC_RESULT(ic))->defs,ic->key);
2720 hTabDeleteItem (&iCodehTab, ic->key, ic, DELETE_ITEM, NULL);
2721 OP_DEFS_SET ((IC_RESULT (dic)), bitVectSetBit (OP_DEFS (IC_RESULT (dic)), dic->key));
2725 OP_SYMBOL (IC_RIGHT (ic))->ruonly = 0;
2731 /* if the type from and type to are the same
2732 then if this is the only use then packit */
2733 if (compareType (operandType (IC_RIGHT (ic)),
2734 operandType (IC_LEFT (ic))) == 1)
2736 iCode *dic = packRegsForOneuse (ic, IC_RIGHT (ic), ebp);
2739 bitVectUnSetBit(OP_SYMBOL(IC_RESULT(dic))->defs,dic->key);
2740 ReplaceOpWithCheaperOp(&IC_RESULT (dic), IC_RESULT (ic));
2741 remiCodeFromeBBlock (ebp, ic);
2742 bitVectUnSetBit(OP_SYMBOL(IC_RESULT(ic))->defs,ic->key);
2743 hTabDeleteItem (&iCodehTab, ic->key, ic, DELETE_ITEM, NULL);
2744 OP_DEFS_SET ((IC_RESULT (dic)), bitVectSetBit (OP_DEFS (IC_RESULT (dic)), dic->key));
2752 iTempNN := (some variable in farspace) V1
2757 if (ic->op == IPUSH)
2759 packForPush (ic, ebpp, blockno);
2763 /* pack registers for accumulator use, when the
2764 result of an arithmetic or bit wise operation
2765 has only one use, that use is immediately following
2766 the defintion and the using iCode has only one
2767 operand or has two operands but one is literal &
2768 the result of that operation is not on stack then
2769 we can leave the result of this operation in acc:b
2771 if ((IS_ARITHMETIC_OP (ic)
2772 || IS_CONDITIONAL(ic)
2773 || IS_BITWISE_OP (ic)
2774 || ic->op == LEFT_OP || ic->op == RIGHT_OP || ic->op == CALL
2775 || (ic->op == ADDRESS_OF && isOperandOnStack (IC_LEFT (ic)))
2777 IS_ITEMP (IC_RESULT (ic)) &&
2778 getSize (operandType (IC_RESULT (ic))) <= 2)
2780 packRegsForAccUse (ic);
2784 /*-----------------------------------------------------------------*/
2785 /* assignRegisters - assigns registers to each live range as need */
2786 /*-----------------------------------------------------------------*/
2788 mcs51_assignRegisters (eBBlock ** ebbs, int count)
2793 setToNull ((void *) &_G.funcrUsed);
2794 setToNull ((void *) &_G.totRegAssigned);
2795 mcs51_ptrRegReq = _G.stackExtend = _G.dataExtend = 0;
2798 /* change assignments this will remove some
2799 live ranges reducing some register pressure */
2800 for (i = 0; i < count; i++)
2801 packRegisters (ebbs, i);
2803 if (options.dump_pack)
2804 dumpEbbsToFileExt (DUMP_PACK, ebbs, count);
2806 /* first determine for each live range the number of
2807 registers & the type of registers required for each */
2810 /* and serially allocate registers */
2811 serialRegAssign (ebbs, count);
2816 /* if stack was extended then tell the user */
2819 /* werror(W_TOOMANY_SPILS,"stack", */
2820 /* _G.stackExtend,currFunc->name,""); */
2826 /* werror(W_TOOMANY_SPILS,"data space", */
2827 /* _G.dataExtend,currFunc->name,""); */
2831 /* after that create the register mask
2832 for each of the instruction */
2833 createRegMask (ebbs, count);
2835 /* redo that offsets for stacked automatic variables */
2836 redoStackOffsets ();
2838 if (options.dump_rassgn)
2840 dumpEbbsToFileExt (DUMP_RASSGN, ebbs, count);
2841 dumpLiveRanges (DUMP_LRANGE, liveRanges);
2844 /* do the overlaysegment stuff SDCCmem.c */
2845 doOverlays (ebbs, count);
2847 /* now get back the chain */
2848 ic = iCodeLabelOptimize (iCodeFromeBBlock (ebbs, count));
2852 /* free up any _G.stackSpil locations allocated */
2853 applyToSet (_G.stackSpil, deallocStackSpil);
2855 setToNull ((void **) &_G.stackSpil);
2856 setToNull ((void **) &_G.spiltSet);
2857 /* mark all registers as free */