1 /*------------------------------------------------------------------------
3 SDCCralloc.c - source file for register allocation. (8051) specific
5 Written By - Sandeep Dutta . sandeep.dutta@usa.net (1998)
7 This program is free software; you can redistribute it and/or modify it
8 under the terms of the GNU General Public License as published by the
9 Free Software Foundation; either version 2, or (at your option) any
12 This program is distributed in the hope that it will be useful,
13 but WITHOUT ANY WARRANTY; without even the implied warranty of
14 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
15 GNU General Public License for more details.
17 You should have received a copy of the GNU General Public License
18 along with this program; if not, write to the Free Software
19 Foundation, 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
21 In other words, you are welcome to use, share and improve this program.
22 You are forbidden to forbid anyone else to use, share and improve
23 what you give them. Help stamp out software-hoarding!
24 -------------------------------------------------------------------------*/
30 /*-----------------------------------------------------------------*/
31 /* At this point we start getting processor specific although */
32 /* some routines are non-processor specific & can be reused when */
33 /* targetting other processors. The decision for this will have */
34 /* to be made on a routine by routine basis */
35 /* routines used to pack registers are most definitely not reusable */
36 /* since the pack the registers depending strictly on the MCU */
37 /*-----------------------------------------------------------------*/
39 extern void gen51Code (iCode *);
48 bitVect *totRegAssigned; /* final set of LRs that got into registers */
51 bitVect *funcrUsed; /* registers used in a function */
57 /* Shared with gen.c */
58 int mcs51_ptrRegReq; /* one byte pointer register required */
64 {REG_GPR, R2_IDX, REG_GPR, "r2", "ar2", "0", 2, 1},
65 {REG_GPR, R3_IDX, REG_GPR, "r3", "ar3", "0", 3, 1},
66 {REG_GPR, R4_IDX, REG_GPR, "r4", "ar4", "0", 4, 1},
67 {REG_GPR, R5_IDX, REG_GPR, "r5", "ar5", "0", 5, 1},
68 {REG_GPR, R6_IDX, REG_GPR, "r6", "ar6", "0", 6, 1},
69 {REG_GPR, R7_IDX, REG_GPR, "r7", "ar7", "0", 7, 1},
70 {REG_PTR, R0_IDX, REG_PTR, "r0", "ar0", "0", 0, 1},
71 {REG_PTR, R1_IDX, REG_PTR, "r1", "ar1", "0", 1, 1},
72 {REG_GPR, X8_IDX, REG_GPR, "x8", "x8", "xreg", 0, 1},
73 {REG_GPR, X9_IDX, REG_GPR, "x9", "x9", "xreg", 1, 1},
74 {REG_GPR, X10_IDX, REG_GPR, "x10", "x10", "xreg", 2, 1},
75 {REG_GPR, X11_IDX, REG_GPR, "x11", "x11", "xreg", 3, 1},
76 {REG_GPR, X12_IDX, REG_GPR, "x12", "x12", "xreg", 4, 1},
77 {REG_CND, CND_IDX, REG_CND, "C", "C", "xreg", 0, 1},
80 static void spillThis (symbol *);
81 static void freeAllRegs ();
83 /*-----------------------------------------------------------------*/
84 /* allocReg - allocates register of given type */
85 /*-----------------------------------------------------------------*/
91 for (i = 0; i < mcs51_nRegs; i++)
94 /* if type is given as 0 then any
95 free register will do */
99 regs8051[i].isFree = 0;
102 bitVectSetBit (currFunc->regsUsed, i);
105 /* other wise look for specific type
107 if (regs8051[i].isFree &&
108 regs8051[i].type == type)
110 regs8051[i].isFree = 0;
113 bitVectSetBit (currFunc->regsUsed, i);
120 /*-----------------------------------------------------------------*/
121 /* mcs51_regWithIdx - returns pointer to register wit index number */
122 /*-----------------------------------------------------------------*/
124 mcs51_regWithIdx (int idx)
128 for (i = 0; i < mcs51_nRegs; i++)
129 if (regs8051[i].rIdx == idx)
132 werror (E_INTERNAL_ERROR, __FILE__, __LINE__,
133 "regWithIdx not found");
137 /*-----------------------------------------------------------------*/
138 /* freeReg - frees a register */
139 /*-----------------------------------------------------------------*/
145 werror (E_INTERNAL_ERROR, __FILE__, __LINE__,
146 "freeReg - Freeing NULL register");
154 /*-----------------------------------------------------------------*/
155 /* nFreeRegs - returns number of free registers */
156 /*-----------------------------------------------------------------*/
163 for (i = 0; i < mcs51_nRegs; i++)
164 if (regs8051[i].isFree && regs8051[i].type == type)
169 /*-----------------------------------------------------------------*/
170 /* nfreeRegsType - free registers with type */
171 /*-----------------------------------------------------------------*/
173 nfreeRegsType (int type)
178 if ((nfr = nFreeRegs (type)) == 0)
179 return nFreeRegs (REG_GPR);
182 return nFreeRegs (type);
185 /*-----------------------------------------------------------------*/
186 /* useReg - marks a register as used */
187 /*-----------------------------------------------------------------*/
194 /*-----------------------------------------------------------------*/
195 /* computeSpillable - given a point find the spillable live ranges */
196 /*-----------------------------------------------------------------*/
198 computeSpillable (iCode * ic)
202 /* spillable live ranges are those that are live at this
203 point . the following categories need to be subtracted
205 a) - those that are already spilt
206 b) - if being used by this one
207 c) - defined by this one */
209 spillable = bitVectCopy (ic->rlive);
211 bitVectCplAnd (spillable, _G.spiltSet); /* those already spilt */
213 bitVectCplAnd (spillable, ic->uses); /* used in this one */
214 bitVectUnSetBit (spillable, ic->defKey);
215 spillable = bitVectIntersect (spillable, _G.regAssigned);
220 /*-----------------------------------------------------------------*/
221 /* noSpilLoc - return true if a variable has no spil location */
222 /*-----------------------------------------------------------------*/
224 noSpilLoc (symbol * sym, eBBlock * ebp, iCode * ic)
226 return (sym->usl.spillLoc ? 0 : 1);
229 /*-----------------------------------------------------------------*/
230 /* hasSpilLoc - will return 1 if the symbol has spil location */
231 /*-----------------------------------------------------------------*/
233 hasSpilLoc (symbol * sym, eBBlock * ebp, iCode * ic)
235 return (sym->usl.spillLoc ? 1 : 0);
238 /*-----------------------------------------------------------------*/
239 /* directSpilLoc - will return 1 if the splilocation is in direct */
240 /*-----------------------------------------------------------------*/
242 directSpilLoc (symbol * sym, eBBlock * ebp, iCode * ic)
244 if (sym->usl.spillLoc &&
245 (IN_DIRSPACE (SPEC_OCLS (sym->usl.spillLoc->etype))))
251 /*-----------------------------------------------------------------*/
252 /* hasSpilLocnoUptr - will return 1 if the symbol has spil location */
253 /* but is not used as a pointer */
254 /*-----------------------------------------------------------------*/
256 hasSpilLocnoUptr (symbol * sym, eBBlock * ebp, iCode * ic)
258 return ((sym->usl.spillLoc && !sym->uptr) ? 1 : 0);
261 /*-----------------------------------------------------------------*/
262 /* rematable - will return 1 if the remat flag is set */
263 /*-----------------------------------------------------------------*/
265 rematable (symbol * sym, eBBlock * ebp, iCode * ic)
270 /*-----------------------------------------------------------------*/
271 /* notUsedInRemaining - not used or defined in remain of the block */
272 /*-----------------------------------------------------------------*/
274 notUsedInRemaining (symbol * sym, eBBlock * ebp, iCode * ic)
276 return ((usedInRemaining (operandFromSymbol (sym), ic) ? 0 : 1) &&
277 allDefsOutOfRange (sym->defs, ebp->fSeq, ebp->lSeq));
280 /*-----------------------------------------------------------------*/
281 /* allLRs - return true for all */
282 /*-----------------------------------------------------------------*/
284 allLRs (symbol * sym, eBBlock * ebp, iCode * ic)
289 /*-----------------------------------------------------------------*/
290 /* liveRangesWith - applies function to a given set of live range */
291 /*-----------------------------------------------------------------*/
293 liveRangesWith (bitVect * lrs, int (func) (symbol *, eBBlock *, iCode *),
294 eBBlock * ebp, iCode * ic)
299 if (!lrs || !lrs->size)
302 for (i = 1; i < lrs->size; i++)
305 if (!bitVectBitValue (lrs, i))
308 /* if we don't find it in the live range
309 hash table we are in serious trouble */
310 if (!(sym = hTabItemWithKey (liveRanges, i)))
312 werror (E_INTERNAL_ERROR, __FILE__, __LINE__,
313 "liveRangesWith could not find liveRange");
317 if (func (sym, ebp, ic) && bitVectBitValue (_G.regAssigned, sym->key))
318 addSetHead (&rset, sym);
325 /*-----------------------------------------------------------------*/
326 /* leastUsedLR - given a set determines which is the least used */
327 /*-----------------------------------------------------------------*/
329 leastUsedLR (set * sset)
331 symbol *sym = NULL, *lsym = NULL;
333 sym = lsym = setFirstItem (sset);
338 for (; lsym; lsym = setNextItem (sset))
341 /* if usage is the same then prefer
342 the spill the smaller of the two */
343 if (lsym->used == sym->used)
344 if (getSize (lsym->type) < getSize (sym->type))
348 if (lsym->used < sym->used)
353 setToNull ((void *) &sset);
358 /*-----------------------------------------------------------------*/
359 /* noOverLap - will iterate through the list looking for over lap */
360 /*-----------------------------------------------------------------*/
362 noOverLap (set * itmpStack, symbol * fsym)
367 for (sym = setFirstItem (itmpStack); sym;
368 sym = setNextItem (itmpStack))
370 if (bitVectBitValue(sym->clashes,fsym->key)) return 0;
376 /*-----------------------------------------------------------------*/
377 /* isFree - will return 1 if the a free spil location is found */
378 /*-----------------------------------------------------------------*/
383 V_ARG (symbol **, sloc);
384 V_ARG (symbol *, fsym);
386 /* if already found */
390 /* if it is free && and the itmp assigned to
391 this does not have any overlapping live ranges
392 with the one currently being assigned and
393 the size can be accomodated */
395 noOverLap (sym->usl.itmpStack, fsym) &&
396 getSize (sym->type) >= getSize (fsym->type))
405 /*-----------------------------------------------------------------*/
406 /* spillLRWithPtrReg :- will spil those live ranges which use PTR */
407 /*-----------------------------------------------------------------*/
409 spillLRWithPtrReg (symbol * forSym)
415 if (!_G.regAssigned ||
416 bitVectIsZero (_G.regAssigned))
419 r0 = mcs51_regWithIdx (R0_IDX);
420 r1 = mcs51_regWithIdx (R1_IDX);
422 /* for all live ranges */
423 for (lrsym = hTabFirstItem (liveRanges, &k); lrsym;
424 lrsym = hTabNextItem (liveRanges, &k))
428 /* if no registers assigned to it or spilt */
429 /* if it does not overlap with this then
430 not need to spill it */
432 if (lrsym->isspilt || !lrsym->nRegs ||
433 (lrsym->liveTo < forSym->liveFrom))
436 /* go thru the registers : if it is either
437 r0 or r1 then spil it */
438 for (j = 0; j < lrsym->nRegs; j++)
439 if (lrsym->regs[j] == r0 ||
440 lrsym->regs[j] == r1)
449 /*-----------------------------------------------------------------*/
450 /* createStackSpil - create a location on the stack to spil */
451 /*-----------------------------------------------------------------*/
453 createStackSpil (symbol * sym)
456 int useXstack, model;
460 /* first go try and find a free one that is already
461 existing on the stack */
462 if (applyToSet (_G.stackSpil, isFree, &sloc, sym))
464 /* found a free one : just update & return */
465 sym->usl.spillLoc = sloc;
468 addSetHead (&sloc->usl.itmpStack, sym);
472 /* could not then have to create one , this is the hard part
473 we need to allocate this on the stack : this is really a
474 hack!! but cannot think of anything better at this time */
476 if (sprintf (slocBuffer, "sloc%d", _G.slocNum++) >= sizeof (slocBuffer))
478 fprintf (stderr, "***Internal error: slocBuffer overflowed: %s:%d\n",
483 sloc = newiTemp (slocBuffer);
485 /* set the type to the spilling symbol */
486 sloc->type = copyLinkChain (sym->type);
487 sloc->etype = getSpec (sloc->type);
488 SPEC_SCLS (sloc->etype) = S_DATA;
489 SPEC_EXTR (sloc->etype) = 0;
490 SPEC_STAT (sloc->etype) = 0;
491 SPEC_VOLATILE(sloc->etype) = 0;
492 SPEC_ABSA(sloc->etype) = 0;
494 /* we don't allow it to be allocated`
495 onto the external stack since : so we
496 temporarily turn it off ; we also
497 turn off memory model to prevent
498 the spil from going to the external storage
501 useXstack = options.useXstack;
502 model = options.model;
503 /* noOverlay = options.noOverlay; */
504 /* options.noOverlay = 1; */
505 options.model = options.useXstack = 0;
509 options.useXstack = useXstack;
510 options.model = model;
511 /* options.noOverlay = noOverlay; */
512 sloc->isref = 1; /* to prevent compiler warning */
514 /* if it is on the stack then update the stack */
515 if (IN_STACK (sloc->etype))
517 currFunc->stack += getSize (sloc->type);
518 _G.stackExtend += getSize (sloc->type);
521 _G.dataExtend += getSize (sloc->type);
523 /* add it to the _G.stackSpil set */
524 addSetHead (&_G.stackSpil, sloc);
525 sym->usl.spillLoc = sloc;
528 /* add it to the set of itempStack set
529 of the spill location */
530 addSetHead (&sloc->usl.itmpStack, sym);
534 /*-----------------------------------------------------------------*/
535 /* isSpiltOnStack - returns true if the spil location is on stack */
536 /*-----------------------------------------------------------------*/
538 isSpiltOnStack (symbol * sym)
548 /* if (sym->_G.stackSpil) */
551 if (!sym->usl.spillLoc)
554 etype = getSpec (sym->usl.spillLoc->type);
555 if (IN_STACK (etype))
561 /*-----------------------------------------------------------------*/
562 /* spillThis - spils a specific operand */
563 /*-----------------------------------------------------------------*/
565 spillThis (symbol * sym)
568 /* if this is rematerializable or has a spillLocation
569 we are okay, else we need to create a spillLocation
571 if (!(sym->remat || sym->usl.spillLoc))
572 createStackSpil (sym);
574 /* mark it has spilt & put it in the spilt set */
575 sym->isspilt = sym->spillA = 1;
576 _G.spiltSet = bitVectSetBit (_G.spiltSet, sym->key);
578 bitVectUnSetBit (_G.regAssigned, sym->key);
579 bitVectUnSetBit (_G.totRegAssigned, sym->key);
581 for (i = 0; i < sym->nRegs; i++)
585 freeReg (sym->regs[i]);
589 /* if spilt on stack then free up r0 & r1
590 if they could have been assigned to some
592 if (!mcs51_ptrRegReq && isSpiltOnStack (sym))
595 spillLRWithPtrReg (sym);
598 if (sym->usl.spillLoc && !sym->remat)
599 sym->usl.spillLoc->allocreq++;
603 /*-----------------------------------------------------------------*/
604 /* selectSpil - select a iTemp to spil : rather a simple procedure */
605 /*-----------------------------------------------------------------*/
607 selectSpil (iCode * ic, eBBlock * ebp, symbol * forSym)
609 bitVect *lrcs = NULL;
613 /* get the spillable live ranges */
614 lrcs = computeSpillable (ic);
616 /* get all live ranges that are rematerizable */
617 if ((selectS = liveRangesWith (lrcs, rematable, ebp, ic)))
620 /* return the least used of these */
621 return leastUsedLR (selectS);
624 /* get live ranges with spillLocations in direct space */
625 if ((selectS = liveRangesWith (lrcs, directSpilLoc, ebp, ic)))
627 sym = leastUsedLR (selectS);
628 strcpy (sym->rname, (sym->usl.spillLoc->rname[0] ?
629 sym->usl.spillLoc->rname :
630 sym->usl.spillLoc->name));
632 /* mark it as allocation required */
633 sym->usl.spillLoc->allocreq++;
637 /* if the symbol is local to the block then */
638 if (forSym->liveTo < ebp->lSeq)
641 /* check if there are any live ranges allocated
642 to registers that are not used in this block */
643 if (!_G.blockSpil && (selectS = liveRangesWith (lrcs, notUsedInBlock, ebp, ic)))
645 sym = leastUsedLR (selectS);
646 /* if this is not rematerializable */
655 /* check if there are any live ranges that not
656 used in the remainder of the block */
657 if (!_G.blockSpil && (selectS = liveRangesWith (lrcs, notUsedInRemaining, ebp, ic)))
659 sym = leastUsedLR (selectS);
672 /* find live ranges with spillocation && not used as pointers */
673 if ((selectS = liveRangesWith (lrcs, hasSpilLocnoUptr, ebp, ic)))
676 sym = leastUsedLR (selectS);
677 /* mark this as allocation required */
678 sym->usl.spillLoc->allocreq++;
682 /* find live ranges with spillocation */
683 if ((selectS = liveRangesWith (lrcs, hasSpilLoc, ebp, ic)))
686 sym = leastUsedLR (selectS);
687 sym->usl.spillLoc->allocreq++;
691 /* couldn't find then we need to create a spil
692 location on the stack , for which one? the least
694 if ((selectS = liveRangesWith (lrcs, noSpilLoc, ebp, ic)))
697 /* return a created spil location */
698 sym = createStackSpil (leastUsedLR (selectS));
699 sym->usl.spillLoc->allocreq++;
703 /* this is an extreme situation we will spill
704 this one : happens very rarely but it does happen */
710 /*-----------------------------------------------------------------*/
711 /* spilSomething - spil some variable & mark registers as free */
712 /*-----------------------------------------------------------------*/
714 spilSomething (iCode * ic, eBBlock * ebp, symbol * forSym)
719 /* get something we can spil */
720 ssym = selectSpil (ic, ebp, forSym);
722 /* mark it as spilt */
723 ssym->isspilt = ssym->spillA = 1;
724 _G.spiltSet = bitVectSetBit (_G.spiltSet, ssym->key);
726 /* mark it as not register assigned &
727 take it away from the set */
728 bitVectUnSetBit (_G.regAssigned, ssym->key);
729 bitVectUnSetBit (_G.totRegAssigned, ssym->key);
731 /* mark the registers as free */
732 for (i = 0; i < ssym->nRegs; i++)
734 freeReg (ssym->regs[i]);
736 /* if spilt on stack then free up r0 & r1
737 if they could have been assigned to as gprs */
738 if (!mcs51_ptrRegReq && isSpiltOnStack (ssym))
741 spillLRWithPtrReg (ssym);
744 /* if this was a block level spil then insert push & pop
745 at the start & end of block respectively */
748 iCode *nic = newiCode (IPUSH, operandFromSymbol (ssym), NULL);
749 /* add push to the start of the block */
750 addiCodeToeBBlock (ebp, nic, (ebp->sch->op == LABEL ?
751 ebp->sch->next : ebp->sch));
752 nic = newiCode (IPOP, operandFromSymbol (ssym), NULL);
753 /* add pop to the end of the block */
754 addiCodeToeBBlock (ebp, nic, NULL);
757 /* if spilt because not used in the remainder of the
758 block then add a push before this instruction and
759 a pop at the end of the block */
760 if (ssym->remainSpil)
763 iCode *nic = newiCode (IPUSH, operandFromSymbol (ssym), NULL);
764 /* add push just before this instruction */
765 addiCodeToeBBlock (ebp, nic, ic);
767 nic = newiCode (IPOP, operandFromSymbol (ssym), NULL);
768 /* add pop to the end of the block */
769 addiCodeToeBBlock (ebp, nic, NULL);
778 /*-----------------------------------------------------------------*/
779 /* getRegPtr - will try for PTR if not a GPR type if not spil */
780 /*-----------------------------------------------------------------*/
782 getRegPtr (iCode * ic, eBBlock * ebp, symbol * sym)
788 /* try for a ptr type */
789 if ((reg = allocReg (REG_PTR)))
792 /* try for gpr type */
793 if ((reg = allocReg (REG_GPR)))
796 /* we have to spil */
797 if (!spilSomething (ic, ebp, sym))
800 /* make sure partially assigned registers aren't reused */
801 for (j=0; j<=sym->nRegs; j++)
803 sym->regs[j]->isFree = 0;
805 /* this looks like an infinite loop but
806 in really selectSpil will abort */
810 /*-----------------------------------------------------------------*/
811 /* getRegGpr - will try for GPR if not spil */
812 /*-----------------------------------------------------------------*/
814 getRegGpr (iCode * ic, eBBlock * ebp, symbol * sym)
820 /* try for gpr type */
821 if ((reg = allocReg (REG_GPR)))
824 if (!mcs51_ptrRegReq)
825 if ((reg = allocReg (REG_PTR)))
828 /* we have to spil */
829 if (!spilSomething (ic, ebp, sym))
832 /* make sure partially assigned registers aren't reused */
833 for (j=0; j<=sym->nRegs; j++)
835 sym->regs[j]->isFree = 0;
837 /* this looks like an infinite loop but
838 in really selectSpil will abort */
842 /*-----------------------------------------------------------------*/
843 /* getRegPtrNoSpil - get it cannot split */
844 /*-----------------------------------------------------------------*/
845 static regs *getRegPtrNoSpil()
849 /* try for a ptr type */
850 if ((reg = allocReg (REG_PTR)))
853 /* try for gpr type */
854 if ((reg = allocReg (REG_GPR)))
859 /* just to make the compiler happy */
863 /*-----------------------------------------------------------------*/
864 /* getRegGprNoSpil - get it cannot split */
865 /*-----------------------------------------------------------------*/
866 static regs *getRegGprNoSpil()
870 if ((reg = allocReg (REG_GPR)))
873 if (!mcs51_ptrRegReq)
874 if ((reg = allocReg (REG_PTR)))
879 /* just to make the compiler happy */
883 /*-----------------------------------------------------------------*/
884 /* symHasReg - symbol has a given register */
885 /*-----------------------------------------------------------------*/
887 symHasReg (symbol * sym, regs * reg)
891 for (i = 0; i < sym->nRegs; i++)
892 if (sym->regs[i] == reg)
898 /*-----------------------------------------------------------------*/
899 /* deassignLRs - check the live to and if they have registers & are */
900 /* not spilt then free up the registers */
901 /*-----------------------------------------------------------------*/
903 deassignLRs (iCode * ic, eBBlock * ebp)
909 for (sym = hTabFirstItem (liveRanges, &k); sym;
910 sym = hTabNextItem (liveRanges, &k))
914 /* if it does not end here */
915 if (sym->liveTo > ic->seq)
918 /* if it was spilt on stack then we can
919 mark the stack spil location as free */
924 sym->usl.spillLoc->isFree = 1;
930 if (!bitVectBitValue (_G.regAssigned, sym->key))
933 /* special case check if this is an IFX &
934 the privious one was a pop and the
935 previous one was not spilt then keep track
937 if (ic->op == IFX && ic->prev &&
938 ic->prev->op == IPOP &&
939 !ic->prev->parmPush &&
940 !OP_SYMBOL (IC_LEFT (ic->prev))->isspilt)
941 psym = OP_SYMBOL (IC_LEFT (ic->prev));
947 bitVectUnSetBit (_G.regAssigned, sym->key);
949 /* if the result of this one needs registers
950 and does not have it then assign it right
952 if (IC_RESULT (ic) &&
953 !(SKIP_IC2 (ic) || /* not a special icode */
954 ic->op == JUMPTABLE ||
960 (result = OP_SYMBOL (IC_RESULT (ic))) && /* has a result */
961 result->liveTo > ic->seq && /* and will live beyond this */
962 result->liveTo <= ebp->lSeq && /* does not go beyond this block */
963 result->regType == sym->regType && /* same register types */
964 result->nRegs && /* which needs registers */
965 !result->isspilt && /* and does not already have them */
967 !bitVectBitValue (_G.regAssigned, result->key) &&
968 /* the number of free regs + number of regs in this LR
969 can accomodate the what result Needs */
970 ((nfreeRegsType (result->regType) +
971 sym->nRegs) >= result->nRegs)
975 for (i = 0; i < result->nRegs; i++)
977 result->regs[i] = sym->regs[i];
979 result->regs[i] = getRegGpr (ic, ebp, result);
981 _G.regAssigned = bitVectSetBit (_G.regAssigned, result->key);
982 _G.totRegAssigned = bitVectSetBit (_G.totRegAssigned, result->key);
986 /* free the remaining */
987 for (; i < sym->nRegs; i++)
991 if (!symHasReg (psym, sym->regs[i]))
992 freeReg (sym->regs[i]);
995 freeReg (sym->regs[i]);
1002 /*-----------------------------------------------------------------*/
1003 /* reassignLR - reassign this to registers */
1004 /*-----------------------------------------------------------------*/
1006 reassignLR (operand * op)
1008 symbol *sym = OP_SYMBOL (op);
1011 /* not spilt any more */
1012 sym->isspilt = sym->spillA = sym->blockSpil = sym->remainSpil = 0;
1013 bitVectUnSetBit (_G.spiltSet, sym->key);
1015 _G.regAssigned = bitVectSetBit (_G.regAssigned, sym->key);
1016 _G.totRegAssigned = bitVectSetBit (_G.totRegAssigned, sym->key);
1020 for (i = 0; i < sym->nRegs; i++)
1021 sym->regs[i]->isFree = 0;
1024 /*-----------------------------------------------------------------*/
1025 /* willCauseSpill - determines if allocating will cause a spill */
1026 /*-----------------------------------------------------------------*/
1028 willCauseSpill (int nr, int rt)
1030 /* first check if there are any avlb registers
1031 of te type required */
1034 /* special case for pointer type
1035 if pointer type not avlb then
1036 check for type gpr */
1037 if (nFreeRegs (rt) >= nr)
1039 if (nFreeRegs (REG_GPR) >= nr)
1044 if (mcs51_ptrRegReq)
1046 if (nFreeRegs (rt) >= nr)
1051 if (nFreeRegs (REG_PTR) +
1052 nFreeRegs (REG_GPR) >= nr)
1057 /* it will cause a spil */
1061 /*-----------------------------------------------------------------*/
1062 /* positionRegs - the allocator can allocate same registers to res- */
1063 /* ult and operand, if this happens make sure they are in the same */
1064 /* position as the operand otherwise chaos results */
1065 /*-----------------------------------------------------------------*/
1067 positionRegs (symbol * result, symbol * opsym)
1069 int count = min (result->nRegs, opsym->nRegs);
1070 int i, j = 0, shared = 0;
1073 /* if the result has been spilt then cannot share */
1078 /* first make sure that they actually share */
1079 for (i = 0; i < count; i++)
1081 for (j = 0; j < count; j++)
1083 if (result->regs[i] == opsym->regs[j] && i != j)
1093 regs *tmp = result->regs[i];
1094 result->regs[i] = result->regs[j];
1095 result->regs[j] = tmp;
1102 /*-----------------------------------------------------------------*/
1103 /* serialRegAssign - serially allocate registers to the variables */
1104 /*-----------------------------------------------------------------*/
1106 serialRegAssign (eBBlock ** ebbs, int count)
1110 /* for all blocks */
1111 for (i = 0; i < count; i++) {
1115 if (ebbs[i]->noPath &&
1116 (ebbs[i]->entryLabel != entryLabel &&
1117 ebbs[i]->entryLabel != returnLabel))
1120 /* of all instructions do */
1121 for (ic = ebbs[i]->sch; ic; ic = ic->next) {
1125 // update the registers in use at the start of this icode
1126 for (reg=0; reg<mcs51_nRegs; reg++) {
1127 if (regs8051[reg].isFree) {
1128 ic->riu &= ~(1<<regs8051[reg].offset);
1130 ic->riu |= (1<<regs8051[reg].offset);
1135 /* if this is an ipop that means some live
1136 range will have to be assigned again */
1138 reassignLR (IC_LEFT (ic));
1140 /* if result is present && is a true symbol */
1141 if (IC_RESULT (ic) && ic->op != IFX &&
1142 IS_TRUE_SYMOP (IC_RESULT (ic)))
1143 OP_SYMBOL (IC_RESULT (ic))->allocreq++;
1145 /* take away registers from live
1146 ranges that end at this instruction */
1147 deassignLRs (ic, ebbs[i]);
1149 /* some don't need registers */
1150 if (SKIP_IC2 (ic) ||
1151 ic->op == JUMPTABLE ||
1155 (IC_RESULT (ic) && POINTER_SET (ic)))
1158 /* now we need to allocate registers
1159 only for the result */
1160 if (IC_RESULT (ic)) {
1161 symbol *sym = OP_SYMBOL (IC_RESULT (ic));
1167 /* if it does not need or is spilt
1168 or is already assigned to registers
1169 or will not live beyond this instructions */
1172 bitVectBitValue (_G.regAssigned, sym->key) ||
1173 sym->liveTo <= ic->seq)
1176 /* if some liverange has been spilt at the block level
1177 and this one live beyond this block then spil this
1179 if (_G.blockSpil && sym->liveTo > ebbs[i]->lSeq) {
1183 /* if trying to allocate this will cause
1184 a spill and there is nothing to spill
1185 or this one is rematerializable then
1187 willCS = willCauseSpill (sym->nRegs, sym->regType);
1188 spillable = computeSpillable (ic);
1189 if (sym->remat || (willCS && bitVectIsZero (spillable))) {
1194 /* if it has a spillocation & is used less than
1195 all other live ranges then spill this */
1197 if (sym->usl.spillLoc) {
1198 symbol *leastUsed = leastUsedLR (liveRangesWith (spillable,
1199 allLRs, ebbs[i], ic));
1200 if (leastUsed && leastUsed->used > sym->used) {
1205 /* if none of the liveRanges have a spillLocation then better
1206 to spill this one than anything else already assigned to registers */
1207 if (liveRangesWith(spillable,noSpilLoc,ebbs[i],ic)) {
1208 /* if this is local to this block then we might find a block spil */
1209 if (!(sym->liveFrom >= ebbs[i]->fSeq && sym->liveTo <= ebbs[i]->lSeq)) {
1216 /* if we need ptr regs for the right side
1218 if (POINTER_GET (ic) && IS_SYMOP (IC_LEFT (ic))
1219 && getSize (OP_SYMBOL (IC_LEFT (ic))->type) <= (unsigned int) PTRSIZE) {
1223 if (IC_LEFT (ic) && IS_SYMOP (IC_LEFT (ic))
1224 && SPEC_OCLS(OP_SYMBOL (IC_LEFT (ic))->etype) == idata) {
1228 if (IC_RIGHT (ic) && IS_SYMOP (IC_RIGHT (ic))
1229 && SPEC_OCLS(OP_SYMBOL (IC_RIGHT (ic))->etype) == idata) {
1234 /* else we assign registers to it */
1235 _G.regAssigned = bitVectSetBit (_G.regAssigned, sym->key);
1236 _G.totRegAssigned = bitVectSetBit (_G.totRegAssigned, sym->key);
1238 for (j = 0; j < sym->nRegs; j++) {
1239 if (sym->regType == REG_PTR)
1240 sym->regs[j] = getRegPtr (ic, ebbs[i], sym);
1242 sym->regs[j] = getRegGpr (ic, ebbs[i], sym);
1244 /* if the allocation failed which means
1245 this was spilt then break */
1246 if (!sym->regs[j]) {
1251 if (!POINTER_SET(ic) && !POINTER_GET(ic)) {
1252 /* if it shares registers with operands make sure
1253 that they are in the same position */
1254 if (IC_LEFT (ic) && IS_SYMOP (IC_LEFT (ic)) &&
1255 OP_SYMBOL (IC_LEFT (ic))->nRegs) {
1256 positionRegs (OP_SYMBOL (IC_RESULT (ic)),
1257 OP_SYMBOL (IC_LEFT (ic)));
1259 /* do the same for the right operand */
1260 if (IC_RIGHT (ic) && IS_SYMOP (IC_RIGHT (ic)) &&
1261 OP_SYMBOL (IC_RIGHT (ic))->nRegs) {
1262 positionRegs (OP_SYMBOL (IC_RESULT (ic)),
1263 OP_SYMBOL (IC_RIGHT (ic)));
1277 /*-----------------------------------------------------------------*/
1278 /* fillGaps - Try to fill in the Gaps left by Pass1 */
1279 /*-----------------------------------------------------------------*/
1280 static void fillGaps()
1286 if (getenv("DISABLE_FILL_GAPS")) return;
1288 /* look for livernages that was spilt by the allocator */
1289 for (sym = hTabFirstItem(liveRanges,&key) ; sym ;
1290 sym = hTabNextItem(liveRanges,&key)) {
1295 if (!sym->spillA || !sym->clashes || sym->remat) continue ;
1297 /* find the liveRanges this one clashes with, that are
1298 still assigned to registers & mark the registers as used*/
1299 for ( i = 0 ; i < sym->clashes->size ; i ++) {
1303 if (bitVectBitValue(sym->clashes,i) == 0 || /* those that clash with this */
1304 bitVectBitValue(_G.totRegAssigned,i) == 0) /* and are still assigned to registers */
1307 clr = hTabItemWithKey(liveRanges,i);
1310 /* mark these registers as used */
1311 for (k = 0 ; k < clr->nRegs ; k++ )
1312 useReg(clr->regs[k]);
1315 if (willCauseSpill(sym->nRegs,sym->regType)) {
1316 /* NOPE :( clear all registers & and continue */
1321 D(printf("Atemping fillGaps on %s: [",sym->name));
1322 /* THERE IS HOPE !!!! */
1323 for (i=0; i < sym->nRegs ; i++ ) {
1324 if (sym->regType == REG_PTR)
1325 sym->regs[i] = getRegPtrNoSpil ();
1327 sym->regs[i] = getRegGprNoSpil ();
1328 D(printf("%s ", sym->regs[i]->name));
1332 /* For all its definitions check if the registers
1333 allocated needs positioning NOTE: we can position
1334 only ONCE if more than One positioning required
1336 We may need to perform the checks twice; once to
1337 position the registers as needed, the second to
1338 verify any register repositioning is still
1342 for (pass=0; pass<2; pass++) {
1343 D(printf(" checking definitions\n"));
1344 for (i = 0 ; i < sym->defs->size ; i++ ) {
1345 if (bitVectBitValue(sym->defs,i)) {
1347 if (!(ic = hTabItemWithKey(iCodehTab,i))) continue ;
1348 D(printf(" ic->seq = %d\n", ic->seq));
1349 if (SKIP_IC(ic)) continue;
1350 assert(isSymbolEqual(sym,OP_SYMBOL(IC_RESULT(ic)))); /* just making sure */
1351 /* if left is assigned to registers */
1352 if (IS_SYMOP(IC_LEFT(ic)))
1354 D(printf(" left = "));
1355 D(printOperand(IC_LEFT(ic),NULL));
1357 if (IS_SYMOP(IC_LEFT(ic)) &&
1358 bitVectBitValue(_G.totRegAssigned,OP_SYMBOL(IC_LEFT(ic))->key)) {
1359 pdone += (positionRegs(sym,OP_SYMBOL(IC_LEFT(ic)))>0);
1361 if (IS_SYMOP(IC_RIGHT(ic)))
1363 D(printf(" right = "));
1364 D(printOperand(IC_RIGHT(ic),NULL));
1366 if (IS_SYMOP(IC_RIGHT(ic)) &&
1367 bitVectBitValue(_G.totRegAssigned,OP_SYMBOL(IC_RIGHT(ic))->key)) {
1368 pdone += (positionRegs(sym,OP_SYMBOL(IC_RIGHT(ic)))>0);
1370 D(printf(" pdone = %d\n", pdone));
1371 if (pdone > 1) break;
1374 D(printf(" checking uses\n"));
1375 for (i = 0 ; i < sym->uses->size ; i++ ) {
1376 if (bitVectBitValue(sym->uses,i)) {
1378 if (!(ic = hTabItemWithKey(iCodehTab,i))) continue ;
1379 D(printf(" ic->seq = %d\n", ic->seq));
1380 if (SKIP_IC(ic)) continue;
1381 if (POINTER_SET(ic) || POINTER_GET(ic)) continue ;
1383 /* if result is assigned to registers */
1384 if (IS_SYMOP(IC_RESULT(ic)))
1386 D(printf(" result = "));
1387 D(printOperand(IC_RESULT(ic),NULL));
1389 if (IS_SYMOP(IC_RESULT(ic)) &&
1390 bitVectBitValue(_G.totRegAssigned,OP_SYMBOL(IC_RESULT(ic))->key)) {
1391 pdone += (positionRegs(sym,OP_SYMBOL(IC_RESULT(ic)))>0);
1393 D(printf(" pdone = %d\n", pdone));
1394 if (pdone > 1) break;
1397 if (pdone == 0) break; /* second pass only if regs repositioned */
1398 if (pdone > 1) break;
1400 D(printf(" sym->regs = ["));
1401 for (i=0; i < sym->nRegs ; i++ )
1402 D(printf("%s ", sym->regs[i]->name));
1404 /* had to position more than once GIVE UP */
1406 /* UNDO all the changes we made to try this */
1408 for (i=0; i < sym->nRegs ; i++ ) {
1409 sym->regs[i] = NULL;
1412 D(printf ("Fill Gap gave up due to positioning for %s in function %s\n",sym->name, currFunc ? currFunc->name : "UNKNOWN"));
1415 D(printf ("FILLED GAP for %s in function %s\n",sym->name, currFunc ? currFunc->name : "UNKNOWN"));
1416 _G.totRegAssigned = bitVectSetBit(_G.totRegAssigned,sym->key);
1417 sym->isspilt = sym->spillA = 0 ;
1418 sym->usl.spillLoc->allocreq--;
1423 /*-----------------------------------------------------------------*/
1424 /* rUmaskForOp :- returns register mask for an operand */
1425 /*-----------------------------------------------------------------*/
1427 mcs51_rUmaskForOp (operand * op)
1433 /* only temporaries are assigned registers */
1437 sym = OP_SYMBOL (op);
1439 /* if spilt or no registers assigned to it
1441 if (sym->isspilt || !sym->nRegs)
1444 rumask = newBitVect (mcs51_nRegs);
1446 for (j = 0; j < sym->nRegs; j++)
1448 rumask = bitVectSetBit (rumask,
1449 sym->regs[j]->rIdx);
1455 /*-----------------------------------------------------------------*/
1456 /* regsUsedIniCode :- returns bit vector of registers used in iCode */
1457 /*-----------------------------------------------------------------*/
1459 regsUsedIniCode (iCode * ic)
1461 bitVect *rmask = newBitVect (mcs51_nRegs);
1463 /* do the special cases first */
1466 rmask = bitVectUnion (rmask,
1467 mcs51_rUmaskForOp (IC_COND (ic)));
1471 /* for the jumptable */
1472 if (ic->op == JUMPTABLE)
1474 rmask = bitVectUnion (rmask,
1475 mcs51_rUmaskForOp (IC_JTCOND (ic)));
1480 /* of all other cases */
1482 rmask = bitVectUnion (rmask,
1483 mcs51_rUmaskForOp (IC_LEFT (ic)));
1487 rmask = bitVectUnion (rmask,
1488 mcs51_rUmaskForOp (IC_RIGHT (ic)));
1491 rmask = bitVectUnion (rmask,
1492 mcs51_rUmaskForOp (IC_RESULT (ic)));
1498 /*-----------------------------------------------------------------*/
1499 /* createRegMask - for each instruction will determine the regsUsed */
1500 /*-----------------------------------------------------------------*/
1502 createRegMask (eBBlock ** ebbs, int count)
1506 /* for all blocks */
1507 for (i = 0; i < count; i++)
1511 if (ebbs[i]->noPath &&
1512 (ebbs[i]->entryLabel != entryLabel &&
1513 ebbs[i]->entryLabel != returnLabel))
1516 /* for all instructions */
1517 for (ic = ebbs[i]->sch; ic; ic = ic->next)
1522 if (SKIP_IC2 (ic) || !ic->rlive)
1525 /* first mark the registers used in this
1527 ic->rUsed = regsUsedIniCode (ic);
1528 _G.funcrUsed = bitVectUnion (_G.funcrUsed, ic->rUsed);
1530 /* now create the register mask for those
1531 registers that are in use : this is a
1532 super set of ic->rUsed */
1533 ic->rMask = newBitVect (mcs51_nRegs + 1);
1535 /* for all live Ranges alive at this point */
1536 for (j = 1; j < ic->rlive->size; j++)
1541 /* if not alive then continue */
1542 if (!bitVectBitValue (ic->rlive, j))
1545 /* find the live range we are interested in */
1546 if (!(sym = hTabItemWithKey (liveRanges, j)))
1548 werror (E_INTERNAL_ERROR, __FILE__, __LINE__,
1549 "createRegMask cannot find live range");
1550 fprintf(stderr, "\tmissing live range: key=%d\n", j);
1554 /* if no register assigned to it */
1555 if (!sym->nRegs || sym->isspilt)
1558 /* for all the registers allocated to it */
1559 for (k = 0; k < sym->nRegs; k++)
1562 bitVectSetBit (ic->rMask, sym->regs[k]->rIdx);
1568 /*-----------------------------------------------------------------*/
1569 /* rematStr - returns the rematerialized string for a remat var */
1570 /*-----------------------------------------------------------------*/
1572 rematStr (symbol * sym)
1575 iCode *ic = sym->rematiCode;
1580 /* if plus or minus print the right hand side */
1581 if (ic->op == '+' || ic->op == '-')
1583 sprintf (s, "0x%04x %c ", (int) operandLitValue (IC_RIGHT (ic)),
1586 ic = OP_SYMBOL (IC_LEFT (ic))->rematiCode;
1590 /* cast then continue */
1591 if (IS_CAST_ICODE(ic)) {
1592 ic = OP_SYMBOL (IC_RIGHT (ic))->rematiCode;
1595 /* we reached the end */
1596 sprintf (s, "%s", OP_SYMBOL (IC_LEFT (ic))->rname);
1603 /*-----------------------------------------------------------------*/
1604 /* regTypeNum - computes the type & number of registers required */
1605 /*-----------------------------------------------------------------*/
1607 regTypeNum (eBBlock *ebbs)
1613 /* for each live range do */
1614 for (sym = hTabFirstItem (liveRanges, &k); sym;
1615 sym = hTabNextItem (liveRanges, &k))
1618 /* if used zero times then no registers needed */
1619 if ((sym->liveTo - sym->liveFrom) == 0)
1623 /* if the live range is a temporary */
1627 /* if the type is marked as a conditional */
1628 if (sym->regType == REG_CND)
1631 /* if used in return only then we don't
1633 if (sym->ruonly || sym->accuse)
1635 if (IS_AGGREGATE (sym->type) || sym->isptr)
1636 sym->type = aggrToPtr (sym->type, FALSE);
1640 /* if the symbol has only one definition &
1641 that definition is a get_pointer */
1642 if (bitVectnBitsOn (sym->defs) == 1 &&
1643 (ic = hTabItemWithKey (iCodehTab,
1644 bitVectFirstBit (sym->defs))) &&
1647 !IS_BITVAR (sym->etype))
1651 /* and that pointer is remat in data space */
1652 if (IS_SYMOP (IC_LEFT (ic)) &&
1653 OP_SYMBOL (IC_LEFT (ic))->remat &&
1654 !IS_CAST_ICODE(OP_SYMBOL (IC_LEFT (ic))->rematiCode) &&
1655 DCL_TYPE (aggrToPtr (operandType(IC_LEFT(ic)), FALSE)) == POINTER)
1657 /* create a psuedo symbol & force a spil */
1658 symbol *psym = newSymbol (rematStr (OP_SYMBOL (IC_LEFT (ic))), 1);
1659 psym->type = sym->type;
1660 psym->etype = sym->etype;
1662 strcpy (psym->rname, psym->name);
1664 sym->usl.spillLoc = psym;
1665 #if 0 // an alternative fix for bug #480076
1666 /* now this is a useless assignment to itself */
1667 remiCodeFromeBBlock (ebbs, ic);
1669 /* now this really is an assignment to itself, make it so;
1670 it will be optimized out later */
1672 ReplaceOpWithCheaperOp(&IC_RIGHT(ic), IC_RESULT(ic));
1678 /* if in data space or idata space then try to
1679 allocate pointer register */
1683 /* if not then we require registers */
1684 sym->nRegs = ((IS_AGGREGATE (sym->type) || sym->isptr) ?
1685 getSize (sym->type = aggrToPtr (sym->type, FALSE)) :
1686 getSize (sym->type));
1690 fprintf (stderr, "allocated more than 4 or 0 registers for type ");
1691 printTypeChain (sym->type, stderr);
1692 fprintf (stderr, "\n");
1695 /* determine the type of register required */
1696 if (sym->nRegs == 1 &&
1697 IS_PTR (sym->type) &&
1699 sym->regType = REG_PTR;
1701 sym->regType = REG_GPR;
1705 /* for the first run we don't provide */
1706 /* registers for true symbols we will */
1707 /* see how things go */
1713 /*-----------------------------------------------------------------*/
1714 /* freeAllRegs - mark all registers as free */
1715 /*-----------------------------------------------------------------*/
1721 for (i = 0; i < mcs51_nRegs; i++)
1722 regs8051[i].isFree = 1;
1725 /*-----------------------------------------------------------------*/
1726 /* deallocStackSpil - this will set the stack pointer back */
1727 /*-----------------------------------------------------------------*/
1729 DEFSETFUNC (deallocStackSpil)
1737 /*-----------------------------------------------------------------*/
1738 /* farSpacePackable - returns the packable icode for far variables */
1739 /*-----------------------------------------------------------------*/
1741 farSpacePackable (iCode * ic)
1745 /* go thru till we find a definition for the
1746 symbol on the right */
1747 for (dic = ic->prev; dic; dic = dic->prev)
1749 /* if the definition is a call then no */
1750 if ((dic->op == CALL || dic->op == PCALL) &&
1751 IC_RESULT (dic)->key == IC_RIGHT (ic)->key)
1756 /* if shift by unknown amount then not */
1757 if ((dic->op == LEFT_OP || dic->op == RIGHT_OP) &&
1758 IC_RESULT (dic)->key == IC_RIGHT (ic)->key)
1761 /* if pointer get and size > 1 */
1762 if (POINTER_GET (dic) &&
1763 getSize (aggrToPtr (operandType (IC_LEFT (dic)), FALSE)) > 1)
1766 if (POINTER_SET (dic) &&
1767 getSize (aggrToPtr (operandType (IC_RESULT (dic)), FALSE)) > 1)
1772 if (IC_COND (dic) &&
1773 IS_TRUE_SYMOP (IC_COND (dic)) &&
1774 isOperandInFarSpace (IC_COND (dic)))
1777 else if (dic->op == JUMPTABLE)
1779 if (IC_JTCOND (dic) &&
1780 IS_TRUE_SYMOP (IC_JTCOND (dic)) &&
1781 isOperandInFarSpace (IC_JTCOND (dic)))
1786 /* if any three is a true symbol in far space */
1787 if (IC_RESULT (dic) &&
1788 IS_TRUE_SYMOP (IC_RESULT (dic)) &&
1789 isOperandInFarSpace (IC_RESULT (dic)))
1792 if (IC_RIGHT (dic) &&
1793 IS_TRUE_SYMOP (IC_RIGHT (dic)) &&
1794 isOperandInFarSpace (IC_RIGHT (dic)) &&
1795 !isOperandEqual (IC_RIGHT (dic), IC_RESULT (ic)))
1798 if (IC_LEFT (dic) &&
1799 IS_TRUE_SYMOP (IC_LEFT (dic)) &&
1800 isOperandInFarSpace (IC_LEFT (dic)) &&
1801 !isOperandEqual (IC_LEFT (dic), IC_RESULT (ic)))
1805 if (isOperandEqual (IC_RIGHT (ic), IC_RESULT (dic)))
1807 if ((dic->op == LEFT_OP ||
1808 dic->op == RIGHT_OP ||
1810 IS_OP_LITERAL (IC_RIGHT (dic)))
1820 /*-----------------------------------------------------------------*/
1821 /* packRegsForAssign - register reduction for assignment */
1822 /*-----------------------------------------------------------------*/
1824 packRegsForAssign (iCode * ic, eBBlock * ebp)
1828 if (!IS_ITEMP (IC_RIGHT (ic)) ||
1829 OP_SYMBOL (IC_RIGHT (ic))->isind ||
1830 OP_LIVETO (IC_RIGHT (ic)) > ic->seq)
1836 /* if the true symbol is defined in far space or on stack
1837 then we should not since this will increase register pressure */
1838 if (isOperandInFarSpace(IC_RESULT(ic)) && !farSpacePackable(ic)) {
1842 /* find the definition of iTempNN scanning backwards if we find a
1843 a use of the true symbol in before we find the definition then
1845 for (dic = ic->prev; dic; dic = dic->prev)
1848 #if 0 /* jwk: This collides with 1.43 but I really see no need for
1849 this anymore. It fixes bug #716790 and substantially improves
1850 redundant register usage around function calls.
1853 /* if there is a function call then don't pack it */
1854 if ((dic->op == CALL || dic->op == PCALL))
1866 if (IS_SYMOP (IC_COND (dic)) &&
1867 (IC_COND (dic)->key == IC_RESULT (ic)->key ||
1868 IC_COND (dic)->key == IC_RIGHT (ic)->key))
1876 if (IS_TRUE_SYMOP (IC_RESULT (dic)) &&
1877 IS_OP_VOLATILE (IC_RESULT (dic)))
1883 if (IS_SYMOP (IC_RESULT (dic)) &&
1884 IC_RESULT (dic)->key == IC_RIGHT (ic)->key)
1886 if (POINTER_SET (dic))
1892 if (IS_SYMOP (IC_RIGHT (dic)) &&
1893 (IC_RIGHT (dic)->key == IC_RESULT (ic)->key ||
1894 IC_RIGHT (dic)->key == IC_RIGHT (ic)->key))
1900 if (IS_SYMOP (IC_LEFT (dic)) &&
1901 (IC_LEFT (dic)->key == IC_RESULT (ic)->key ||
1902 IC_LEFT (dic)->key == IC_RIGHT (ic)->key))
1908 if (POINTER_SET (dic) &&
1909 IC_RESULT (dic)->key == IC_RESULT (ic)->key)
1918 return 0; /* did not find */
1920 /* if assignment then check that right is not a bit */
1921 if (ASSIGNMENT (dic) && !POINTER_SET (dic))
1923 sym_link *etype = operandType (IC_RIGHT (dic));
1924 if (IS_BITFIELD (etype))
1926 /* if result is a bit too then it's ok */
1927 etype = operandType (IC_RESULT (dic));
1928 if (!IS_BITFIELD (etype))
1932 /* if the result is on stack or iaccess then it must be
1933 the same atleast one of the operands */
1934 if (OP_SYMBOL (IC_RESULT (ic))->onStack ||
1935 OP_SYMBOL (IC_RESULT (ic))->iaccess)
1938 /* the operation has only one symbol
1939 operator then we can pack */
1940 if ((IC_LEFT (dic) && !IS_SYMOP (IC_LEFT (dic))) ||
1941 (IC_RIGHT (dic) && !IS_SYMOP (IC_RIGHT (dic))))
1944 if (!((IC_LEFT (dic) &&
1945 IC_RESULT (ic)->key == IC_LEFT (dic)->key) ||
1947 IC_RESULT (ic)->key == IC_RIGHT (dic)->key)))
1951 /* found the definition */
1952 /* replace the result with the result of */
1953 /* this assignment and remove this assignment */
1954 bitVectUnSetBit(OP_SYMBOL(IC_RESULT(dic))->defs,dic->key);
1955 ReplaceOpWithCheaperOp(&IC_RESULT (dic), IC_RESULT (ic));
1957 if (IS_ITEMP (IC_RESULT (dic)) && OP_SYMBOL (IC_RESULT (dic))->liveFrom > dic->seq)
1959 OP_SYMBOL (IC_RESULT (dic))->liveFrom = dic->seq;
1961 // TODO: and the otherway around?
1963 /* delete from liverange table also
1964 delete from all the points inbetween and the new
1966 for (sic = dic; sic != ic; sic = sic->next)
1968 bitVectUnSetBit (sic->rlive, IC_RESULT (ic)->key);
1969 if (IS_ITEMP (IC_RESULT (dic)))
1970 bitVectSetBit (sic->rlive, IC_RESULT (dic)->key);
1973 remiCodeFromeBBlock (ebp, ic);
1974 bitVectUnSetBit(OP_SYMBOL(IC_RESULT(ic))->defs,ic->key);
1975 hTabDeleteItem (&iCodehTab, ic->key, ic, DELETE_ITEM, NULL);
1976 OP_DEFS(IC_RESULT (dic))=bitVectSetBit (OP_DEFS (IC_RESULT (dic)), dic->key);
1980 /*------------------------------------------------------------------*/
1981 /* findAssignToSym : scanning backwards looks for first assig found */
1982 /*------------------------------------------------------------------*/
1984 findAssignToSym (operand * op, iCode * ic)
1988 /* This routine is used to find sequences like
1990 ...; (intervening ops don't use iTempAA or modify FOO)
1991 blah = blah + iTempAA;
1993 and eliminate the use of iTempAA, freeing up its register for
1998 for (dic = ic->prev; dic; dic = dic->prev)
2001 /* if definition by assignment */
2002 if (dic->op == '=' &&
2003 !POINTER_SET (dic) &&
2004 IC_RESULT (dic)->key == op->key
2005 /* && IS_TRUE_SYMOP(IC_RIGHT(dic)) */
2007 break; /* found where this temp was defined */
2009 /* if we find an usage then we cannot delete it */
2013 if (IC_COND (dic) && IC_COND (dic)->key == op->key)
2016 else if (dic->op == JUMPTABLE)
2018 if (IC_JTCOND (dic) && IC_JTCOND (dic)->key == op->key)
2023 if (IC_LEFT (dic) && IC_LEFT (dic)->key == op->key)
2026 if (IC_RIGHT (dic) && IC_RIGHT (dic)->key == op->key)
2029 if (POINTER_SET (dic) && IC_RESULT (dic)->key == op->key)
2035 return NULL; /* didn't find any assignment to op */
2037 /* we are interested only if defined in far space */
2038 /* or in stack space in case of + & - */
2040 /* if assigned to a non-symbol then don't repack regs */
2041 if (!IS_SYMOP (IC_RIGHT (dic)))
2044 /* if the symbol is volatile then we should not */
2045 if (isOperandVolatile (IC_RIGHT (dic), TRUE))
2047 /* XXX TODO --- should we be passing FALSE to isOperandVolatile()?
2048 What does it mean for an iTemp to be volatile, anyway? Passing
2049 TRUE is more cautious but may prevent possible optimizations */
2051 /* if the symbol is in far space then we should not */
2052 if (isOperandInFarSpace (IC_RIGHT (dic)))
2055 /* for + & - operations make sure that
2056 if it is on the stack it is the same
2057 as one of the three operands */
2058 if ((ic->op == '+' || ic->op == '-') &&
2059 OP_SYMBOL (IC_RIGHT (dic))->onStack)
2062 if (IC_RESULT (ic)->key != IC_RIGHT (dic)->key &&
2063 IC_LEFT (ic)->key != IC_RIGHT (dic)->key &&
2064 IC_RIGHT (ic)->key != IC_RIGHT (dic)->key)
2068 /* now make sure that the right side of dic
2069 is not defined between ic & dic */
2072 iCode *sic = dic->next;
2074 for (; sic != ic; sic = sic->next)
2075 if (IC_RESULT (sic) &&
2076 IC_RESULT (sic)->key == IC_RIGHT (dic)->key)
2083 /*-----------------------------------------------------------------*/
2084 /* reassignAliasedSym - used by packRegsForSupport to replace */
2085 /* redundant iTemp with equivalent symbol */
2086 /*-----------------------------------------------------------------*/
2088 reassignAliasedSym (eBBlock *ebp, iCode *assignment, iCode *use, operand *op)
2091 unsigned oldSymKey, newSymKey;
2093 oldSymKey = op->key;
2094 newSymKey = IC_RIGHT(assignment)->key;
2096 /* only track live ranges of compiler-generated temporaries */
2097 if (!IS_ITEMP(IC_RIGHT(assignment)))
2100 /* update the live-value bitmaps */
2101 for (ic = assignment; ic != use; ic = ic->next) {
2102 bitVectUnSetBit (ic->rlive, oldSymKey);
2104 ic->rlive = bitVectSetBit (ic->rlive, newSymKey);
2107 /* update the sym of the used operand */
2108 OP_SYMBOL(op) = OP_SYMBOL(IC_RIGHT(assignment));
2109 op->key = OP_SYMBOL(op)->key;
2111 /* update the sym's liverange */
2112 if ( OP_LIVETO(op) < ic->seq )
2113 setToRange(op, ic->seq, FALSE);
2115 /* remove the assignment iCode now that its result is unused */
2116 remiCodeFromeBBlock (ebp, assignment);
2117 bitVectUnSetBit(OP_SYMBOL(IC_RESULT(assignment))->defs, assignment->key);
2118 hTabDeleteItem (&iCodehTab, assignment->key, assignment, DELETE_ITEM, NULL);
2122 /*-----------------------------------------------------------------*/
2123 /* packRegsForSupport :- reduce some registers for support calls */
2124 /*-----------------------------------------------------------------*/
2126 packRegsForSupport (iCode * ic, eBBlock * ebp)
2130 /* for the left & right operand :- look to see if the
2131 left was assigned a true symbol in far space in that
2132 case replace them */
2134 if (IS_ITEMP (IC_LEFT (ic)) &&
2135 OP_SYMBOL (IC_LEFT (ic))->liveTo <= ic->seq)
2137 dic = findAssignToSym (IC_LEFT (ic), ic);
2141 /* found it we need to remove it from the block */
2142 reassignAliasedSym (ebp, dic, ic, IC_LEFT(ic));
2147 /* do the same for the right operand */
2148 if (IS_ITEMP (IC_RIGHT (ic)) &&
2149 OP_SYMBOL (IC_RIGHT (ic))->liveTo <= ic->seq)
2151 iCode *dic = findAssignToSym (IC_RIGHT (ic), ic);
2155 /* if this is a subtraction & the result
2156 is a true symbol in far space then don't pack */
2157 if (ic->op == '-' && IS_TRUE_SYMOP (IC_RESULT (dic)))
2159 sym_link *etype = getSpec (operandType (IC_RESULT (dic)));
2160 if (IN_FARSPACE (SPEC_OCLS (etype)))
2163 /* found it we need to remove it from the
2165 reassignAliasedSym (ebp, dic, ic, IC_RIGHT(ic));
2174 #define IS_OP_RUONLY(x) (x && IS_SYMOP(x) && OP_SYMBOL(x)->ruonly)
2177 /*-----------------------------------------------------------------*/
2178 /* packRegsForOneuse : - will reduce some registers for single Use */
2179 /*-----------------------------------------------------------------*/
2181 packRegsForOneuse (iCode * ic, operand * op, eBBlock * ebp)
2186 /* if returning a literal then do nothing */
2190 /* only upto 2 bytes since we cannot predict
2191 the usage of b, & acc */
2192 if (getSize (operandType (op)) > (fReturnSizeMCS51 - 2))
2195 if (ic->op != RETURN &&
2197 !POINTER_SET (ic) &&
2201 if (ic->op == SEND && ic->argreg != 1) return NULL;
2203 /* this routine will mark the a symbol as used in one
2204 instruction use only && if the defintion is local
2205 (ie. within the basic block) && has only one definition &&
2206 that definiion is either a return value from a
2207 function or does not contain any variables in
2209 uses = bitVectCopy (OP_USES (op));
2210 bitVectUnSetBit (uses, ic->key); /* take away this iCode */
2211 if (!bitVectIsZero (uses)) /* has other uses */
2214 /* if it has only one defintion */
2215 if (bitVectnBitsOn (OP_DEFS (op)) > 1)
2216 return NULL; /* has more than one definition */
2218 /* get that definition */
2220 hTabItemWithKey (iCodehTab,
2221 bitVectFirstBit (OP_DEFS (op)))))
2224 /* if that only usage is a cast */
2225 if (dic->op == CAST) {
2226 /* to a bigger type */
2227 if (getSize(OP_SYM_TYPE(IC_RESULT(dic))) >
2228 getSize(OP_SYM_TYPE(IC_RIGHT(dic)))) {
2229 /* than we can not, since we cannot predict the usage of b & acc */
2234 /* found the definition now check if it is local */
2235 if (dic->seq < ebp->fSeq ||
2236 dic->seq > ebp->lSeq)
2237 return NULL; /* non-local */
2239 /* now check if it is the return from
2241 if (dic->op == CALL || dic->op == PCALL)
2243 if (ic->op != SEND && ic->op != RETURN &&
2244 !POINTER_SET(ic) && !POINTER_GET(ic))
2246 OP_SYMBOL (op)->ruonly = 1;
2253 /* otherwise check that the definition does
2254 not contain any symbols in far space */
2255 if (isOperandInFarSpace (IC_LEFT (dic)) ||
2256 isOperandInFarSpace (IC_RIGHT (dic)) ||
2257 IS_OP_RUONLY (IC_LEFT (ic)) ||
2258 IS_OP_RUONLY (IC_RIGHT (ic)))
2263 /* if pointer set then make sure the pointer
2265 if (POINTER_SET (dic) &&
2266 !IS_DATA_PTR (aggrToPtr (operandType (IC_RESULT (dic)), FALSE)))
2269 if (POINTER_GET (dic) &&
2270 !IS_DATA_PTR (aggrToPtr (operandType (IC_LEFT (dic)), FALSE)))
2275 /* also make sure the intervenening instructions
2276 don't have any thing in far space */
2277 for (dic = dic->next; dic && dic != ic && sic != ic; dic = dic->next)
2280 /* if there is an intervening function call then no */
2281 if (dic->op == CALL || dic->op == PCALL)
2283 /* if pointer set then make sure the pointer
2285 if (POINTER_SET (dic) &&
2286 !IS_DATA_PTR (aggrToPtr (operandType (IC_RESULT (dic)), FALSE)))
2289 if (POINTER_GET (dic) &&
2290 !IS_DATA_PTR (aggrToPtr (operandType (IC_LEFT (dic)), FALSE)))
2293 /* if address of & the result is remat the okay */
2294 if (dic->op == ADDRESS_OF &&
2295 OP_SYMBOL (IC_RESULT (dic))->remat)
2298 /* if operand has size of three or more & this
2299 operation is a '*','/' or '%' then 'b' may
2301 if ((dic->op == '%' || dic->op == '/' || dic->op == '*') &&
2302 getSize (operandType (op)) >= 3)
2305 /* if left or right or result is in far space */
2306 if (isOperandInFarSpace (IC_LEFT (dic)) ||
2307 isOperandInFarSpace (IC_RIGHT (dic)) ||
2308 isOperandInFarSpace (IC_RESULT (dic)) ||
2309 IS_OP_RUONLY (IC_LEFT (dic)) ||
2310 IS_OP_RUONLY (IC_RIGHT (dic)) ||
2311 IS_OP_RUONLY (IC_RESULT (dic)))
2315 /* if left or right or result is on stack */
2316 if (isOperandOnStack(IC_LEFT(dic)) ||
2317 isOperandOnStack(IC_RIGHT(dic)) ||
2318 isOperandOnStack(IC_RESULT(dic))) {
2323 OP_SYMBOL (op)->ruonly = 1;
2327 /*-----------------------------------------------------------------*/
2328 /* isBitwiseOptimizable - requirements of JEAN LOUIS VERN */
2329 /*-----------------------------------------------------------------*/
2331 isBitwiseOptimizable (iCode * ic)
2333 sym_link *ltype = getSpec (operandType (IC_LEFT (ic)));
2334 sym_link *rtype = getSpec (operandType (IC_RIGHT (ic)));
2336 /* bitwise operations are considered optimizable
2337 under the following conditions (Jean-Louis VERN)
2349 if (IS_LITERAL(rtype) ||
2350 (IS_BITVAR (ltype) && IN_BITSPACE (SPEC_OCLS (ltype))))
2356 /*-----------------------------------------------------------------*/
2357 /* isCommutativeOp - tests whether this op cares what order its */
2358 /* operands are in */
2359 /*-----------------------------------------------------------------*/
2360 bool isCommutativeOp(unsigned int op)
2362 if (op == '+' || op == '*' || op == EQ_OP ||
2363 op == '^' || op == '|' || op == BITWISEAND)
2369 /*-----------------------------------------------------------------*/
2370 /* operandUsesAcc - determines whether the code generated for this */
2371 /* operand will have to use the accumulator */
2372 /*-----------------------------------------------------------------*/
2373 bool operandUsesAcc(operand *op)
2379 symbol *sym = OP_SYMBOL(op);
2383 return TRUE; /* duh! */
2385 if (IN_STACK(sym->etype) || sym->onStack ||
2386 (SPIL_LOC(op) && SPIL_LOC(op)->onStack))
2387 return TRUE; /* acc is used to calc stack offset */
2392 sym = SPIL_LOC(op); /* if spilled, look at spill location */
2394 return FALSE; /* more checks? */
2398 symspace = SPEC_OCLS(sym->etype);
2400 if (sym->iaccess && symspace->paged)
2401 return TRUE; /* must fetch paged indirect sym via accumulator */
2403 if (IN_BITSPACE(symspace))
2404 return TRUE; /* fetching bit vars uses the accumulator */
2406 if (IN_FARSPACE(symspace) || IN_CODESPACE(symspace))
2407 return TRUE; /* fetched via accumulator and dptr */
2413 /*-----------------------------------------------------------------*/
2414 /* packRegsForAccUse - pack registers for acc use */
2415 /*-----------------------------------------------------------------*/
2417 packRegsForAccUse (iCode * ic)
2421 /* if this is an aggregate, e.g. a one byte char array */
2422 if (IS_AGGREGATE(operandType(IC_RESULT(ic)))) {
2426 /* if we are calling a reentrant function that has stack parameters */
2427 if (ic->op == CALL &&
2428 IFFUNC_ISREENT(operandType(IC_LEFT(ic))) &&
2429 FUNC_HASSTACKPARM(operandType(IC_LEFT(ic))))
2432 if (ic->op == PCALL &&
2433 IFFUNC_ISREENT(operandType(IC_LEFT(ic))->next) &&
2434 FUNC_HASSTACKPARM(operandType(IC_LEFT(ic))->next))
2437 /* if + or - then it has to be one byte result */
2438 if ((ic->op == '+' || ic->op == '-')
2439 && getSize (operandType (IC_RESULT (ic))) > 1)
2442 /* if shift operation make sure right side is not a literal */
2443 if (ic->op == RIGHT_OP &&
2444 (isOperandLiteral (IC_RIGHT (ic)) ||
2445 getSize (operandType (IC_RESULT (ic))) > 1))
2448 if (ic->op == LEFT_OP &&
2449 (isOperandLiteral (IC_RIGHT (ic)) ||
2450 getSize (operandType (IC_RESULT (ic))) > 1))
2453 if (IS_BITWISE_OP (ic) &&
2454 getSize (operandType (IC_RESULT (ic))) > 1)
2458 /* has only one definition */
2459 if (bitVectnBitsOn (OP_DEFS (IC_RESULT (ic))) > 1)
2462 /* has only one use */
2463 if (bitVectnBitsOn (OP_USES (IC_RESULT (ic))) > 1)
2466 /* and the usage immediately follows this iCode */
2467 if (!(uic = hTabItemWithKey (iCodehTab,
2468 bitVectFirstBit (OP_USES (IC_RESULT (ic))))))
2471 if (ic->next != uic)
2474 /* if it is a conditional branch then we definitely can */
2478 if (uic->op == JUMPTABLE)
2481 if (POINTER_SET (uic) &&
2482 getSize (aggrToPtr (operandType (IC_RESULT (uic)), FALSE)) > 1)
2485 /* if the usage is not is an assignment
2486 or an arithmetic / bitwise / shift operation then not */
2487 if (uic->op != '=' &&
2488 !IS_ARITHMETIC_OP (uic) &&
2489 !IS_BITWISE_OP (uic) &&
2490 uic->op != LEFT_OP &&
2491 uic->op != RIGHT_OP)
2494 /* if used in ^ operation then make sure right is not a
2495 literal (WIML: Why is this?) */
2496 if (uic->op == '^' && isOperandLiteral (IC_RIGHT (uic)))
2499 /* if shift operation make sure right side is not a literal */
2500 /* WIML: Why is this? */
2501 if (uic->op == RIGHT_OP &&
2502 (isOperandLiteral (IC_RIGHT (uic)) ||
2503 getSize (operandType (IC_RESULT (uic))) > 1))
2505 if (uic->op == LEFT_OP &&
2506 (isOperandLiteral (IC_RIGHT (uic)) ||
2507 getSize (operandType (IC_RESULT (uic))) > 1))
2510 /* make sure that the result of this icode is not on the
2511 stack, since acc is used to compute stack offset */
2513 if (IS_TRUE_SYMOP (IC_RESULT (uic)) &&
2514 OP_SYMBOL (IC_RESULT (uic))->onStack)
2517 if (isOperandOnStack(IC_RESULT(uic)))
2521 /* if the usage has only one operand then we can */
2522 if (IC_LEFT (uic) == NULL ||
2523 IC_RIGHT (uic) == NULL)
2526 /* if the other operand uses the accumulator then we cannot */
2527 if ( (IC_LEFT(uic)->key == IC_RESULT(ic)->key &&
2528 operandUsesAcc(IC_RIGHT(uic))) ||
2529 (IC_RIGHT(uic)->key == IC_RESULT(ic)->key &&
2530 operandUsesAcc(IC_LEFT(uic))) )
2533 /* make sure this is on the left side if not commutative */
2534 /* except for '-', which has been written to be able to
2535 handle reversed operands */
2536 if (!(isCommutativeOp(ic->op) || ic->op == '-') &&
2537 IC_LEFT (uic)->key != IC_RESULT (ic)->key)
2541 // this is too dangerous and need further restrictions
2544 /* if one of them is a literal then we can */
2545 if ((IC_LEFT (uic) && IS_OP_LITERAL (IC_LEFT (uic))) ||
2546 (IC_RIGHT (uic) && IS_OP_LITERAL (IC_RIGHT (uic))))
2548 OP_SYMBOL (IC_RESULT (ic))->accuse = 1;
2554 OP_SYMBOL (IC_RESULT (ic))->accuse = 1;
2558 /*-----------------------------------------------------------------*/
2559 /* packForPush - hueristics to reduce iCode for pushing */
2560 /*-----------------------------------------------------------------*/
2562 packForPush (iCode * ic, eBBlock ** ebpp, int blockno)
2566 struct eBBlock * ebp=ebpp[blockno];
2568 if (ic->op != IPUSH || !IS_ITEMP (IC_LEFT (ic)))
2571 /* must have only definition & one usage */
2572 if (bitVectnBitsOn (OP_DEFS (IC_LEFT (ic))) != 1 ||
2573 bitVectnBitsOn (OP_USES (IC_LEFT (ic))) != 1)
2576 /* find the definition */
2577 if (!(dic = hTabItemWithKey (iCodehTab,
2578 bitVectFirstBit (OP_DEFS (IC_LEFT (ic))))))
2581 if (dic->op != '=' || POINTER_SET (dic))
2584 if (dic->seq < ebp->fSeq) { // Evelyn did this
2586 for (i=0; i<blockno; i++) {
2587 if (dic->seq >= ebpp[i]->fSeq && dic->seq <= ebpp[i]->lSeq) {
2592 wassert (i!=blockno); // no way to recover from here
2595 if (IS_SYMOP(IC_RIGHT(dic))) {
2596 /* make sure the right side does not have any definitions
2598 dbv = OP_DEFS(IC_RIGHT(dic));
2599 for (lic = ic; lic && lic != dic ; lic = lic->prev) {
2600 if (bitVectBitValue(dbv,lic->key))
2603 /* make sure they have the same type */
2604 if (IS_SPEC(operandType(IC_LEFT(ic))))
2606 sym_link *itype=operandType(IC_LEFT(ic));
2607 sym_link *ditype=operandType(IC_RIGHT(dic));
2609 if (SPEC_USIGN(itype)!=SPEC_USIGN(ditype) ||
2610 SPEC_LONG(itype)!=SPEC_LONG(ditype))
2613 /* extend the live range of replaced operand if needed */
2614 if (OP_SYMBOL(IC_RIGHT(dic))->liveTo < ic->seq) {
2615 OP_SYMBOL(IC_RIGHT(dic))->liveTo = ic->seq;
2617 bitVectUnSetBit(OP_SYMBOL(IC_RESULT(dic))->defs,dic->key);
2620 /* we now we know that it has one & only one def & use
2621 and the that the definition is an assignment */
2622 ReplaceOpWithCheaperOp(&IC_LEFT (ic), IC_RIGHT (dic));
2623 remiCodeFromeBBlock (ebp, dic);
2624 hTabDeleteItem (&iCodehTab, dic->key, dic, DELETE_ITEM, NULL);
2627 /*-----------------------------------------------------------------*/
2628 /* packRegisters - does some transformations to reduce register */
2630 /*-----------------------------------------------------------------*/
2632 packRegisters (eBBlock ** ebpp, int blockno)
2636 eBBlock *ebp=ebpp[blockno];
2643 /* look for assignments of the form */
2644 /* iTempNN = TRueSym (someoperation) SomeOperand */
2646 /* TrueSym := iTempNN:1 */
2647 for (ic = ebp->sch; ic; ic = ic->next)
2649 /* find assignment of the form TrueSym := iTempNN:1 */
2650 if (ic->op == '=' && !POINTER_SET (ic))
2651 change += packRegsForAssign (ic, ebp);
2658 for (ic = ebp->sch; ic; ic = ic->next)
2660 /* if this is an itemp & result of an address of a true sym
2661 then mark this as rematerialisable */
2662 if (ic->op == ADDRESS_OF &&
2663 IS_ITEMP (IC_RESULT (ic)) &&
2664 IS_TRUE_SYMOP (IC_LEFT (ic)) &&
2665 bitVectnBitsOn (OP_DEFS (IC_RESULT (ic))) == 1 &&
2666 !OP_SYMBOL (IC_LEFT (ic))->onStack)
2669 OP_SYMBOL (IC_RESULT (ic))->remat = 1;
2670 OP_SYMBOL (IC_RESULT (ic))->rematiCode = ic;
2671 OP_SYMBOL (IC_RESULT (ic))->usl.spillLoc = NULL;
2675 /* if straight assignment then carry remat flag if
2676 this is the only definition */
2677 if (ic->op == '=' &&
2678 !POINTER_SET (ic) &&
2679 IS_SYMOP (IC_RIGHT (ic)) &&
2680 OP_SYMBOL (IC_RIGHT (ic))->remat &&
2681 !IS_CAST_ICODE(OP_SYMBOL (IC_RIGHT (ic))->rematiCode) &&
2682 bitVectnBitsOn (OP_SYMBOL (IC_RESULT (ic))->defs) <= 1)
2685 OP_SYMBOL (IC_RESULT (ic))->remat =
2686 OP_SYMBOL (IC_RIGHT (ic))->remat;
2687 OP_SYMBOL (IC_RESULT (ic))->rematiCode =
2688 OP_SYMBOL (IC_RIGHT (ic))->rematiCode;
2691 /* if cast to a generic pointer & the pointer being
2692 cast is remat, then we can remat this cast as well */
2693 if (ic->op == CAST &&
2694 IS_SYMOP(IC_RIGHT(ic)) &&
2695 OP_SYMBOL(IC_RIGHT(ic))->remat &&
2696 bitVectnBitsOn (OP_DEFS (IC_RESULT (ic))) == 1) {
2697 sym_link *to_type = operandType(IC_LEFT(ic));
2698 sym_link *from_type = operandType(IC_RIGHT(ic));
2699 if (IS_GENPTR(to_type) && IS_PTR(from_type)) {
2700 OP_SYMBOL (IC_RESULT (ic))->remat = 1;
2701 OP_SYMBOL (IC_RESULT (ic))->rematiCode = ic;
2702 OP_SYMBOL (IC_RESULT (ic))->usl.spillLoc = NULL;
2706 /* if this is a +/- operation with a rematerizable
2707 then mark this as rematerializable as well */
2708 if ((ic->op == '+' || ic->op == '-') &&
2709 (IS_SYMOP (IC_LEFT (ic)) &&
2710 IS_ITEMP (IC_RESULT (ic)) &&
2711 IS_OP_LITERAL (IC_RIGHT (ic))) &&
2712 OP_SYMBOL (IC_LEFT (ic))->remat &&
2713 (!IS_SYMOP (IC_RIGHT (ic)) || !IS_CAST_ICODE(OP_SYMBOL (IC_RIGHT (ic))->rematiCode)) &&
2714 bitVectnBitsOn (OP_DEFS (IC_RESULT (ic))) == 1)
2716 OP_SYMBOL (IC_RESULT (ic))->remat = 1;
2717 OP_SYMBOL (IC_RESULT (ic))->rematiCode = ic;
2718 OP_SYMBOL (IC_RESULT (ic))->usl.spillLoc = NULL;
2721 /* mark the pointer usages */
2722 if (POINTER_SET (ic))
2723 OP_SYMBOL (IC_RESULT (ic))->uptr = 1;
2725 if (POINTER_GET (ic) &&
2726 IS_SYMOP(IC_LEFT (ic)))
2727 OP_SYMBOL (IC_LEFT (ic))->uptr = 1;
2731 /* if we are using a symbol on the stack
2732 then we should say mcs51_ptrRegReq */
2733 if (ic->op == IFX && IS_SYMOP (IC_COND (ic)))
2734 mcs51_ptrRegReq += ((OP_SYMBOL (IC_COND (ic))->onStack ||
2735 OP_SYMBOL (IC_COND (ic))->iaccess) ? 1 : 0);
2736 else if (ic->op == JUMPTABLE && IS_SYMOP (IC_JTCOND (ic)))
2737 mcs51_ptrRegReq += ((OP_SYMBOL (IC_JTCOND (ic))->onStack ||
2738 OP_SYMBOL (IC_JTCOND (ic))->iaccess) ? 1 : 0);
2741 if (IS_SYMOP (IC_LEFT (ic)))
2742 mcs51_ptrRegReq += ((OP_SYMBOL (IC_LEFT (ic))->onStack ||
2743 OP_SYMBOL (IC_LEFT (ic))->iaccess) ? 1 : 0);
2744 if (IS_SYMOP (IC_RIGHT (ic)))
2745 mcs51_ptrRegReq += ((OP_SYMBOL (IC_RIGHT (ic))->onStack ||
2746 OP_SYMBOL (IC_RIGHT (ic))->iaccess) ? 1 : 0);
2747 if (IS_SYMOP (IC_RESULT (ic)))
2748 mcs51_ptrRegReq += ((OP_SYMBOL (IC_RESULT (ic))->onStack ||
2749 OP_SYMBOL (IC_RESULT (ic))->iaccess) ? 1 : 0);
2753 /* if the condition of an if instruction
2754 is defined in the previous instruction and
2755 this is the only usage then
2756 mark the itemp as a conditional */
2757 if ((IS_CONDITIONAL (ic) ||
2758 (IS_BITWISE_OP(ic) && isBitwiseOptimizable (ic))) &&
2759 ic->next && ic->next->op == IFX &&
2760 bitVectnBitsOn (OP_USES(IC_RESULT(ic)))==1 &&
2761 isOperandEqual (IC_RESULT (ic), IC_COND (ic->next)) &&
2762 OP_SYMBOL (IC_RESULT (ic))->liveTo <= ic->next->seq)
2764 OP_SYMBOL (IC_RESULT (ic))->regType = REG_CND;
2768 /* reduce for support function calls */
2769 if (ic->supportRtn || ic->op == '+' || ic->op == '-')
2770 packRegsForSupport (ic, ebp);
2772 /* some cases the redundant moves can
2773 can be eliminated for return statements */
2774 if ((ic->op == RETURN || (ic->op == SEND && ic->argreg == 1)) &&
2775 !isOperandInFarSpace (IC_LEFT (ic)) &&
2776 options.model == MODEL_SMALL) {
2777 packRegsForOneuse (ic, IC_LEFT (ic), ebp);
2780 /* if pointer set & left has a size more than
2781 one and right is not in far space */
2782 if (POINTER_SET (ic) &&
2783 !isOperandInFarSpace (IC_RIGHT (ic)) &&
2784 !OP_SYMBOL (IC_RESULT (ic))->remat &&
2785 !IS_OP_RUONLY (IC_RIGHT (ic)) &&
2786 getSize (aggrToPtr (operandType (IC_RESULT (ic)), FALSE)) > 1)
2787 packRegsForOneuse (ic, IC_RESULT (ic), ebp);
2789 /* if pointer get */
2790 if (POINTER_GET (ic) &&
2791 IS_SYMOP (IC_LEFT (ic)) &&
2792 !isOperandInFarSpace (IC_RESULT (ic)) &&
2793 !OP_SYMBOL (IC_LEFT (ic))->remat &&
2794 !IS_OP_RUONLY (IC_RESULT (ic)) &&
2795 getSize (aggrToPtr (operandType (IC_LEFT (ic)), FALSE)) > 1)
2796 packRegsForOneuse (ic, IC_LEFT (ic), ebp);
2799 /* if this is cast for intergral promotion then
2800 check if only use of the definition of the
2801 operand being casted/ if yes then replace
2802 the result of that arithmetic operation with
2803 this result and get rid of the cast */
2806 sym_link *fromType = operandType (IC_RIGHT (ic));
2807 sym_link *toType = operandType (IC_LEFT (ic));
2809 if (IS_INTEGRAL (fromType) && IS_INTEGRAL (toType) &&
2810 getSize (fromType) != getSize (toType) &&
2811 SPEC_USIGN (fromType) == SPEC_USIGN (toType))
2814 iCode *dic = packRegsForOneuse (ic, IC_RIGHT (ic), ebp);
2817 if (IS_ARITHMETIC_OP (dic))
2819 bitVectUnSetBit(OP_SYMBOL(IC_RESULT(dic))->defs,dic->key);
2820 ReplaceOpWithCheaperOp(&IC_RESULT (dic), IC_RESULT (ic));
2821 remiCodeFromeBBlock (ebp, ic);
2822 bitVectUnSetBit(OP_SYMBOL(IC_RESULT(ic))->defs,ic->key);
2823 hTabDeleteItem (&iCodehTab, ic->key, ic, DELETE_ITEM, NULL);
2824 OP_DEFS(IC_RESULT (dic))=bitVectSetBit (OP_DEFS (IC_RESULT (dic)), dic->key);
2828 OP_SYMBOL (IC_RIGHT (ic))->ruonly = 0;
2834 /* if the type from and type to are the same
2835 then if this is the only use then packit */
2836 if (compareType (operandType (IC_RIGHT (ic)),
2837 operandType (IC_LEFT (ic))) == 1)
2839 iCode *dic = packRegsForOneuse (ic, IC_RIGHT (ic), ebp);
2842 bitVectUnSetBit(OP_SYMBOL(IC_RESULT(dic))->defs,dic->key);
2843 ReplaceOpWithCheaperOp(&IC_RESULT (dic), IC_RESULT (ic));
2844 remiCodeFromeBBlock (ebp, ic);
2845 bitVectUnSetBit(OP_SYMBOL(IC_RESULT(ic))->defs,ic->key);
2846 hTabDeleteItem (&iCodehTab, ic->key, ic, DELETE_ITEM, NULL);
2847 OP_DEFS(IC_RESULT (dic))=bitVectSetBit (OP_DEFS (IC_RESULT (dic)), dic->key);
2855 iTempNN := (some variable in farspace) V1
2860 if (ic->op == IPUSH)
2862 packForPush (ic, ebpp, blockno);
2866 /* pack registers for accumulator use, when the
2867 result of an arithmetic or bit wise operation
2868 has only one use, that use is immediately following
2869 the defintion and the using iCode has only one
2870 operand or has two operands but one is literal &
2871 the result of that operation is not on stack then
2872 we can leave the result of this operation in acc:b
2874 if ((IS_ARITHMETIC_OP (ic)
2875 || IS_CONDITIONAL(ic)
2876 || IS_BITWISE_OP (ic)
2877 || ic->op == LEFT_OP || ic->op == RIGHT_OP || ic->op == CALL
2878 || (ic->op == ADDRESS_OF && isOperandOnStack (IC_LEFT (ic)))
2880 IS_ITEMP (IC_RESULT (ic)) &&
2881 getSize (operandType (IC_RESULT (ic))) <= 2)
2883 packRegsForAccUse (ic);
2887 /*-----------------------------------------------------------------*/
2888 /* assignRegisters - assigns registers to each live range as need */
2889 /*-----------------------------------------------------------------*/
2891 mcs51_assignRegisters (eBBlock ** ebbs, int count)
2896 setToNull ((void *) &_G.funcrUsed);
2897 setToNull ((void *) &_G.regAssigned);
2898 setToNull ((void *) &_G.totRegAssigned);
2899 mcs51_ptrRegReq = _G.stackExtend = _G.dataExtend = 0;
2902 /* change assignments this will remove some
2903 live ranges reducing some register pressure */
2905 for (i = 0; i < count; i++)
2906 packRegisters (ebbs, i);
2908 /* liveranges probably changed by register packing
2909 so we compute them again */
2910 recomputeLiveRanges (ebbs, count);
2912 if (options.dump_pack)
2913 dumpEbbsToFileExt (DUMP_PACK, ebbs, count);
2915 /* first determine for each live range the number of
2916 registers & the type of registers required for each */
2919 /* and serially allocate registers */
2920 serialRegAssign (ebbs, count);
2923 //setToNull ((void *) &_G.regAssigned);
2924 //setToNull ((void *) &_G.totRegAssigned);
2927 /* if stack was extended then tell the user */
2930 /* werror(W_TOOMANY_SPILS,"stack", */
2931 /* _G.stackExtend,currFunc->name,""); */
2937 /* werror(W_TOOMANY_SPILS,"data space", */
2938 /* _G.dataExtend,currFunc->name,""); */
2942 /* after that create the register mask
2943 for each of the instruction */
2944 createRegMask (ebbs, count);
2946 /* redo that offsets for stacked automatic variables */
2948 redoStackOffsets ();
2951 if (options.dump_rassgn)
2953 dumpEbbsToFileExt (DUMP_RASSGN, ebbs, count);
2954 dumpLiveRanges (DUMP_LRANGE, liveRanges);
2957 /* do the overlaysegment stuff SDCCmem.c */
2958 doOverlays (ebbs, count);
2960 /* now get back the chain */
2961 ic = iCodeLabelOptimize (iCodeFromeBBlock (ebbs, count));
2965 /* free up any _G.stackSpil locations allocated */
2966 applyToSet (_G.stackSpil, deallocStackSpil);
2968 setToNull ((void *) &_G.stackSpil);
2969 setToNull ((void *) &_G.spiltSet);
2970 /* mark all registers as free */