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", "psw", "0xd0", 0, 1},
78 {0, DPL_IDX, 0, "dpl", "dpl", "0x82", 0, 0},
79 {0, DPH_IDX, 0, "dph", "dph", "0x83", 0, 0},
80 {0, B_IDX, 0, "b", "b", "0xf0", 0, 0},
81 {0, A_IDX, 0, "a", "acc", "0xe0", 0, 0},
84 static void spillThis (symbol *);
85 static void freeAllRegs ();
87 /*-----------------------------------------------------------------*/
88 /* allocReg - allocates register of given type */
89 /*-----------------------------------------------------------------*/
95 for (i = 0; i < mcs51_nRegs; i++)
98 /* if type is given as 0 then any
99 free register will do */
103 regs8051[i].isFree = 0;
106 bitVectSetBit (currFunc->regsUsed, i);
109 /* other wise look for specific type
111 if (regs8051[i].isFree &&
112 regs8051[i].type == type)
114 regs8051[i].isFree = 0;
117 bitVectSetBit (currFunc->regsUsed, i);
124 /*-----------------------------------------------------------------*/
125 /* allocThisReg - allocates a particular register (if free) */
126 /*-----------------------------------------------------------------*/
128 allocThisReg (regs * reg)
135 currFunc->regsUsed = bitVectSetBit (currFunc->regsUsed, reg->rIdx);
141 /*-----------------------------------------------------------------*/
142 /* mcs51_regWithIdx - returns pointer to register wit index number */
143 /*-----------------------------------------------------------------*/
145 mcs51_regWithIdx (int idx)
149 for (i = 0; i < sizeof(regs8051)/sizeof(regs); i++)
150 if (regs8051[i].rIdx == idx)
153 werror (E_INTERNAL_ERROR, __FILE__, __LINE__,
154 "regWithIdx not found");
158 /*-----------------------------------------------------------------*/
159 /* freeReg - frees a register */
160 /*-----------------------------------------------------------------*/
166 werror (E_INTERNAL_ERROR, __FILE__, __LINE__,
167 "freeReg - Freeing NULL register");
175 /*-----------------------------------------------------------------*/
176 /* nFreeRegs - returns number of free registers */
177 /*-----------------------------------------------------------------*/
184 for (i = 0; i < mcs51_nRegs; i++)
185 if (regs8051[i].isFree && regs8051[i].type == type)
190 /*-----------------------------------------------------------------*/
191 /* nfreeRegsType - free registers with type */
192 /*-----------------------------------------------------------------*/
194 nfreeRegsType (int type)
199 if ((nfr = nFreeRegs (type)) == 0)
200 return nFreeRegs (REG_GPR);
203 return nFreeRegs (type);
206 /*-----------------------------------------------------------------*/
207 /* useReg - marks a register as used */
208 /*-----------------------------------------------------------------*/
215 /*-----------------------------------------------------------------*/
216 /* computeSpillable - given a point find the spillable live ranges */
217 /*-----------------------------------------------------------------*/
219 computeSpillable (iCode * ic)
223 /* spillable live ranges are those that are live at this
224 point . the following categories need to be subtracted
226 a) - those that are already spilt
227 b) - if being used by this one
228 c) - defined by this one */
230 spillable = bitVectCopy (ic->rlive);
232 bitVectCplAnd (spillable, _G.spiltSet); /* those already spilt */
234 bitVectCplAnd (spillable, ic->uses); /* used in this one */
235 bitVectUnSetBit (spillable, ic->defKey);
236 spillable = bitVectIntersect (spillable, _G.regAssigned);
241 /*-----------------------------------------------------------------*/
242 /* noSpilLoc - return true if a variable has no spil location */
243 /*-----------------------------------------------------------------*/
245 noSpilLoc (symbol * sym, eBBlock * ebp, iCode * ic)
247 return (sym->usl.spillLoc ? 0 : 1);
250 /*-----------------------------------------------------------------*/
251 /* hasSpilLoc - will return 1 if the symbol has spil location */
252 /*-----------------------------------------------------------------*/
254 hasSpilLoc (symbol * sym, eBBlock * ebp, iCode * ic)
256 return (sym->usl.spillLoc ? 1 : 0);
259 /*-----------------------------------------------------------------*/
260 /* directSpilLoc - will return 1 if the splilocation is in direct */
261 /*-----------------------------------------------------------------*/
263 directSpilLoc (symbol * sym, eBBlock * ebp, iCode * ic)
265 if (sym->usl.spillLoc &&
266 (IN_DIRSPACE (SPEC_OCLS (sym->usl.spillLoc->etype))))
272 /*-----------------------------------------------------------------*/
273 /* hasSpilLocnoUptr - will return 1 if the symbol has spil location */
274 /* but is not used as a pointer */
275 /*-----------------------------------------------------------------*/
277 hasSpilLocnoUptr (symbol * sym, eBBlock * ebp, iCode * ic)
279 return ((sym->usl.spillLoc && !sym->uptr) ? 1 : 0);
282 /*-----------------------------------------------------------------*/
283 /* rematable - will return 1 if the remat flag is set */
284 /*-----------------------------------------------------------------*/
286 rematable (symbol * sym, eBBlock * ebp, iCode * ic)
291 /*-----------------------------------------------------------------*/
292 /* notUsedInRemaining - not used or defined in remain of the block */
293 /*-----------------------------------------------------------------*/
295 notUsedInRemaining (symbol * sym, eBBlock * ebp, iCode * ic)
297 return ((usedInRemaining (operandFromSymbol (sym), ic) ? 0 : 1) &&
298 allDefsOutOfRange (sym->defs, ebp->fSeq, ebp->lSeq));
301 /*-----------------------------------------------------------------*/
302 /* allLRs - return true for all */
303 /*-----------------------------------------------------------------*/
305 allLRs (symbol * sym, eBBlock * ebp, iCode * ic)
310 /*-----------------------------------------------------------------*/
311 /* liveRangesWith - applies function to a given set of live range */
312 /*-----------------------------------------------------------------*/
314 liveRangesWith (bitVect * lrs, int (func) (symbol *, eBBlock *, iCode *),
315 eBBlock * ebp, iCode * ic)
320 if (!lrs || !lrs->size)
323 for (i = 1; i < lrs->size; i++)
326 if (!bitVectBitValue (lrs, i))
329 /* if we don't find it in the live range
330 hash table we are in serious trouble */
331 if (!(sym = hTabItemWithKey (liveRanges, i)))
333 werror (E_INTERNAL_ERROR, __FILE__, __LINE__,
334 "liveRangesWith could not find liveRange");
338 if (func (sym, ebp, ic) && bitVectBitValue (_G.regAssigned, sym->key))
339 addSetHead (&rset, sym);
346 /*-----------------------------------------------------------------*/
347 /* leastUsedLR - given a set determines which is the least used */
348 /*-----------------------------------------------------------------*/
350 leastUsedLR (set * sset)
352 symbol *sym = NULL, *lsym = NULL;
354 sym = lsym = setFirstItem (sset);
359 for (; lsym; lsym = setNextItem (sset))
362 /* if usage is the same then prefer
363 the spill the smaller of the two */
364 if (lsym->used == sym->used)
365 if (getSize (lsym->type) < getSize (sym->type))
369 if (lsym->used < sym->used)
374 setToNull ((void *) &sset);
379 /*-----------------------------------------------------------------*/
380 /* noOverLap - will iterate through the list looking for over lap */
381 /*-----------------------------------------------------------------*/
383 noOverLap (set * itmpStack, symbol * fsym)
388 for (sym = setFirstItem (itmpStack); sym;
389 sym = setNextItem (itmpStack))
391 if (bitVectBitValue(sym->clashes,fsym->key)) return 0;
397 /*-----------------------------------------------------------------*/
398 /* isFree - will return 1 if the a free spil location is found */
399 /*-----------------------------------------------------------------*/
404 V_ARG (symbol **, sloc);
405 V_ARG (symbol *, fsym);
407 /* if already found */
411 /* if it is free && and the itmp assigned to
412 this does not have any overlapping live ranges
413 with the one currently being assigned and
414 the size can be accomodated */
416 noOverLap (sym->usl.itmpStack, fsym) &&
417 getSize (sym->type) >= getSize (fsym->type))
426 /*-----------------------------------------------------------------*/
427 /* spillLRWithPtrReg :- will spil those live ranges which use PTR */
428 /*-----------------------------------------------------------------*/
430 spillLRWithPtrReg (symbol * forSym)
436 if (!_G.regAssigned ||
437 bitVectIsZero (_G.regAssigned))
440 r0 = mcs51_regWithIdx (R0_IDX);
441 r1 = mcs51_regWithIdx (R1_IDX);
443 /* for all live ranges */
444 for (lrsym = hTabFirstItem (liveRanges, &k); lrsym;
445 lrsym = hTabNextItem (liveRanges, &k))
449 /* if no registers assigned to it or spilt */
450 /* if it does not overlap with this then
451 not need to spill it */
453 if (lrsym->isspilt || !lrsym->nRegs ||
454 (lrsym->liveTo < forSym->liveFrom))
457 /* go thru the registers : if it is either
458 r0 or r1 then spil it */
459 for (j = 0; j < lrsym->nRegs; j++)
460 if (lrsym->regs[j] == r0 ||
461 lrsym->regs[j] == r1)
470 /*-----------------------------------------------------------------*/
471 /* createStackSpil - create a location on the stack to spil */
472 /*-----------------------------------------------------------------*/
474 createStackSpil (symbol * sym)
477 int useXstack, model;
481 /* first go try and find a free one that is already
482 existing on the stack */
483 if (applyToSet (_G.stackSpil, isFree, &sloc, sym))
485 /* found a free one : just update & return */
486 sym->usl.spillLoc = sloc;
489 addSetHead (&sloc->usl.itmpStack, sym);
493 /* could not then have to create one , this is the hard part
494 we need to allocate this on the stack : this is really a
495 hack!! but cannot think of anything better at this time */
497 if (sprintf (slocBuffer, "sloc%d", _G.slocNum++) >= sizeof (slocBuffer))
499 fprintf (stderr, "***Internal error: slocBuffer overflowed: %s:%d\n",
504 sloc = newiTemp (slocBuffer);
506 /* set the type to the spilling symbol */
507 sloc->type = copyLinkChain (sym->type);
508 sloc->etype = getSpec (sloc->type);
509 SPEC_SCLS (sloc->etype) = S_DATA;
510 SPEC_EXTR (sloc->etype) = 0;
511 SPEC_STAT (sloc->etype) = 0;
512 SPEC_VOLATILE(sloc->etype) = 0;
513 SPEC_ABSA(sloc->etype) = 0;
515 /* we don't allow it to be allocated`
516 onto the external stack since : so we
517 temporarily turn it off ; we also
518 turn off memory model to prevent
519 the spil from going to the external storage
522 useXstack = options.useXstack;
523 model = options.model;
524 /* noOverlay = options.noOverlay; */
525 /* options.noOverlay = 1; */
526 options.model = options.useXstack = 0;
530 options.useXstack = useXstack;
531 options.model = model;
532 /* options.noOverlay = noOverlay; */
533 sloc->isref = 1; /* to prevent compiler warning */
535 /* if it is on the stack then update the stack */
536 if (IN_STACK (sloc->etype))
538 currFunc->stack += getSize (sloc->type);
539 _G.stackExtend += getSize (sloc->type);
542 _G.dataExtend += getSize (sloc->type);
544 /* add it to the _G.stackSpil set */
545 addSetHead (&_G.stackSpil, sloc);
546 sym->usl.spillLoc = sloc;
549 /* add it to the set of itempStack set
550 of the spill location */
551 addSetHead (&sloc->usl.itmpStack, sym);
555 /*-----------------------------------------------------------------*/
556 /* isSpiltOnStack - returns true if the spil location is on stack */
557 /*-----------------------------------------------------------------*/
559 isSpiltOnStack (symbol * sym)
569 /* if (sym->_G.stackSpil) */
572 if (!sym->usl.spillLoc)
575 etype = getSpec (sym->usl.spillLoc->type);
576 if (IN_STACK (etype))
582 /*-----------------------------------------------------------------*/
583 /* spillThis - spils a specific operand */
584 /*-----------------------------------------------------------------*/
586 spillThis (symbol * sym)
589 /* if this is rematerializable or has a spillLocation
590 we are okay, else we need to create a spillLocation
592 if (!(sym->remat || sym->usl.spillLoc))
593 createStackSpil (sym);
595 /* mark it has spilt & put it in the spilt set */
596 sym->isspilt = sym->spillA = 1;
597 _G.spiltSet = bitVectSetBit (_G.spiltSet, sym->key);
599 bitVectUnSetBit (_G.regAssigned, sym->key);
600 bitVectUnSetBit (_G.totRegAssigned, sym->key);
602 for (i = 0; i < sym->nRegs; i++)
606 freeReg (sym->regs[i]);
610 /* if spilt on stack then free up r0 & r1
611 if they could have been assigned to some
613 if (!mcs51_ptrRegReq && isSpiltOnStack (sym))
616 spillLRWithPtrReg (sym);
619 if (sym->usl.spillLoc && !sym->remat)
620 sym->usl.spillLoc->allocreq++;
624 /*-----------------------------------------------------------------*/
625 /* selectSpil - select a iTemp to spil : rather a simple procedure */
626 /*-----------------------------------------------------------------*/
628 selectSpil (iCode * ic, eBBlock * ebp, symbol * forSym)
630 bitVect *lrcs = NULL;
634 /* get the spillable live ranges */
635 lrcs = computeSpillable (ic);
637 /* get all live ranges that are rematerizable */
638 if ((selectS = liveRangesWith (lrcs, rematable, ebp, ic)))
641 /* return the least used of these */
642 return leastUsedLR (selectS);
645 /* get live ranges with spillLocations in direct space */
646 if ((selectS = liveRangesWith (lrcs, directSpilLoc, ebp, ic)))
648 sym = leastUsedLR (selectS);
649 strcpy (sym->rname, (sym->usl.spillLoc->rname[0] ?
650 sym->usl.spillLoc->rname :
651 sym->usl.spillLoc->name));
653 /* mark it as allocation required */
654 sym->usl.spillLoc->allocreq++;
658 /* if the symbol is local to the block then */
659 if (forSym->liveTo < ebp->lSeq)
662 /* check if there are any live ranges allocated
663 to registers that are not used in this block */
664 if (!_G.blockSpil && (selectS = liveRangesWith (lrcs, notUsedInBlock, ebp, ic)))
666 sym = leastUsedLR (selectS);
667 /* if this is not rematerializable */
676 /* check if there are any live ranges that not
677 used in the remainder of the block */
678 if (!_G.blockSpil && (selectS = liveRangesWith (lrcs, notUsedInRemaining, ebp, ic)))
680 sym = leastUsedLR (selectS);
693 /* find live ranges with spillocation && not used as pointers */
694 if ((selectS = liveRangesWith (lrcs, hasSpilLocnoUptr, ebp, ic)))
697 sym = leastUsedLR (selectS);
698 /* mark this as allocation required */
699 sym->usl.spillLoc->allocreq++;
703 /* find live ranges with spillocation */
704 if ((selectS = liveRangesWith (lrcs, hasSpilLoc, ebp, ic)))
707 sym = leastUsedLR (selectS);
708 sym->usl.spillLoc->allocreq++;
712 /* couldn't find then we need to create a spil
713 location on the stack , for which one? the least
715 if ((selectS = liveRangesWith (lrcs, noSpilLoc, ebp, ic)))
718 /* return a created spil location */
719 sym = createStackSpil (leastUsedLR (selectS));
720 sym->usl.spillLoc->allocreq++;
724 /* this is an extreme situation we will spill
725 this one : happens very rarely but it does happen */
731 /*-----------------------------------------------------------------*/
732 /* spilSomething - spil some variable & mark registers as free */
733 /*-----------------------------------------------------------------*/
735 spilSomething (iCode * ic, eBBlock * ebp, symbol * forSym)
740 /* get something we can spil */
741 ssym = selectSpil (ic, ebp, forSym);
743 /* mark it as spilt */
744 ssym->isspilt = ssym->spillA = 1;
745 _G.spiltSet = bitVectSetBit (_G.spiltSet, ssym->key);
747 /* mark it as not register assigned &
748 take it away from the set */
749 bitVectUnSetBit (_G.regAssigned, ssym->key);
750 bitVectUnSetBit (_G.totRegAssigned, ssym->key);
752 /* mark the registers as free */
753 for (i = 0; i < ssym->nRegs; i++)
755 freeReg (ssym->regs[i]);
757 /* if spilt on stack then free up r0 & r1
758 if they could have been assigned to as gprs */
759 if (!mcs51_ptrRegReq && isSpiltOnStack (ssym))
762 spillLRWithPtrReg (ssym);
765 /* if this was a block level spil then insert push & pop
766 at the start & end of block respectively */
769 iCode *nic = newiCode (IPUSH, operandFromSymbol (ssym), NULL);
770 /* add push to the start of the block */
771 addiCodeToeBBlock (ebp, nic, (ebp->sch->op == LABEL ?
772 ebp->sch->next : ebp->sch));
773 nic = newiCode (IPOP, operandFromSymbol (ssym), NULL);
774 /* add pop to the end of the block */
775 addiCodeToeBBlock (ebp, nic, NULL);
778 /* if spilt because not used in the remainder of the
779 block then add a push before this instruction and
780 a pop at the end of the block */
781 if (ssym->remainSpil)
784 iCode *nic = newiCode (IPUSH, operandFromSymbol (ssym), NULL);
785 /* add push just before this instruction */
786 addiCodeToeBBlock (ebp, nic, ic);
788 nic = newiCode (IPOP, operandFromSymbol (ssym), NULL);
789 /* add pop to the end of the block */
790 addiCodeToeBBlock (ebp, nic, NULL);
799 /*-----------------------------------------------------------------*/
800 /* getRegPtr - will try for PTR if not a GPR type if not spil */
801 /*-----------------------------------------------------------------*/
803 getRegPtr (iCode * ic, eBBlock * ebp, symbol * sym)
809 /* try for a ptr type */
810 if ((reg = allocReg (REG_PTR)))
813 /* try for gpr type */
814 if ((reg = allocReg (REG_GPR)))
817 /* we have to spil */
818 if (!spilSomething (ic, ebp, sym))
821 /* make sure partially assigned registers aren't reused */
822 for (j=0; j<=sym->nRegs; j++)
824 sym->regs[j]->isFree = 0;
826 /* this looks like an infinite loop but
827 in really selectSpil will abort */
831 /*-----------------------------------------------------------------*/
832 /* getRegGpr - will try for GPR if not spil */
833 /*-----------------------------------------------------------------*/
835 getRegGpr (iCode * ic, eBBlock * ebp, symbol * sym)
841 /* try for gpr type */
842 if ((reg = allocReg (REG_GPR)))
845 if (!mcs51_ptrRegReq)
846 if ((reg = allocReg (REG_PTR)))
849 /* we have to spil */
850 if (!spilSomething (ic, ebp, sym))
853 /* make sure partially assigned registers aren't reused */
854 for (j=0; j<=sym->nRegs; j++)
856 sym->regs[j]->isFree = 0;
858 /* this looks like an infinite loop but
859 in really selectSpil will abort */
863 /*-----------------------------------------------------------------*/
864 /* getRegPtrNoSpil - get it cannot split */
865 /*-----------------------------------------------------------------*/
866 static regs *getRegPtrNoSpil()
870 /* try for a ptr type */
871 if ((reg = allocReg (REG_PTR)))
874 /* try for gpr type */
875 if ((reg = allocReg (REG_GPR)))
880 /* just to make the compiler happy */
884 /*-----------------------------------------------------------------*/
885 /* getRegGprNoSpil - get it cannot split */
886 /*-----------------------------------------------------------------*/
887 static regs *getRegGprNoSpil()
891 if ((reg = allocReg (REG_GPR)))
894 if (!mcs51_ptrRegReq)
895 if ((reg = allocReg (REG_PTR)))
900 /* just to make the compiler happy */
904 /*-----------------------------------------------------------------*/
905 /* symHasReg - symbol has a given register */
906 /*-----------------------------------------------------------------*/
908 symHasReg (symbol * sym, regs * reg)
912 for (i = 0; i < sym->nRegs; i++)
913 if (sym->regs[i] == reg)
919 /*-----------------------------------------------------------------*/
920 /* deassignLRs - check the live to and if they have registers & are */
921 /* not spilt then free up the registers */
922 /*-----------------------------------------------------------------*/
924 deassignLRs (iCode * ic, eBBlock * ebp)
930 for (sym = hTabFirstItem (liveRanges, &k); sym;
931 sym = hTabNextItem (liveRanges, &k))
935 /* if it does not end here */
936 if (sym->liveTo > ic->seq)
939 /* if it was spilt on stack then we can
940 mark the stack spil location as free */
945 sym->usl.spillLoc->isFree = 1;
951 if (!bitVectBitValue (_G.regAssigned, sym->key))
954 /* special case check if this is an IFX &
955 the privious one was a pop and the
956 previous one was not spilt then keep track
958 if (ic->op == IFX && ic->prev &&
959 ic->prev->op == IPOP &&
960 !ic->prev->parmPush &&
961 !OP_SYMBOL (IC_LEFT (ic->prev))->isspilt)
962 psym = OP_SYMBOL (IC_LEFT (ic->prev));
968 bitVectUnSetBit (_G.regAssigned, sym->key);
970 /* if the result of this one needs registers
971 and does not have it then assign it right
973 if (IC_RESULT (ic) &&
974 !(SKIP_IC2 (ic) || /* not a special icode */
975 ic->op == JUMPTABLE ||
981 (result = OP_SYMBOL (IC_RESULT (ic))) && /* has a result */
982 result->liveTo > ic->seq && /* and will live beyond this */
983 result->liveTo <= ebp->lSeq && /* does not go beyond this block */
984 result->liveFrom == ic->seq && /* does not start before here */
985 result->regType == sym->regType && /* same register types */
986 result->nRegs && /* which needs registers */
987 !result->isspilt && /* and does not already have them */
989 !bitVectBitValue (_G.regAssigned, result->key) &&
990 /* the number of free regs + number of regs in this LR
991 can accomodate the what result Needs */
992 ((nfreeRegsType (result->regType) +
993 sym->nRegs) >= result->nRegs)
997 for (i = 0; i < result->nRegs; i++)
999 result->regs[i] = sym->regs[i];
1001 result->regs[i] = getRegGpr (ic, ebp, result);
1003 _G.regAssigned = bitVectSetBit (_G.regAssigned, result->key);
1004 _G.totRegAssigned = bitVectSetBit (_G.totRegAssigned, result->key);
1008 /* free the remaining */
1009 for (; i < sym->nRegs; i++)
1013 if (!symHasReg (psym, sym->regs[i]))
1014 freeReg (sym->regs[i]);
1017 freeReg (sym->regs[i]);
1024 /*-----------------------------------------------------------------*/
1025 /* reassignLR - reassign this to registers */
1026 /*-----------------------------------------------------------------*/
1028 reassignLR (operand * op)
1030 symbol *sym = OP_SYMBOL (op);
1033 /* not spilt any more */
1034 sym->isspilt = sym->spillA = sym->blockSpil = sym->remainSpil = 0;
1035 bitVectUnSetBit (_G.spiltSet, sym->key);
1037 _G.regAssigned = bitVectSetBit (_G.regAssigned, sym->key);
1038 _G.totRegAssigned = bitVectSetBit (_G.totRegAssigned, sym->key);
1042 for (i = 0; i < sym->nRegs; i++)
1043 sym->regs[i]->isFree = 0;
1046 /*-----------------------------------------------------------------*/
1047 /* willCauseSpill - determines if allocating will cause a spill */
1048 /*-----------------------------------------------------------------*/
1050 willCauseSpill (int nr, int rt)
1052 /* first check if there are any avlb registers
1053 of te type required */
1056 /* special case for pointer type
1057 if pointer type not avlb then
1058 check for type gpr */
1059 if (nFreeRegs (rt) >= nr)
1061 if (nFreeRegs (REG_GPR) >= nr)
1066 if (mcs51_ptrRegReq)
1068 if (nFreeRegs (rt) >= nr)
1073 if (nFreeRegs (REG_PTR) +
1074 nFreeRegs (REG_GPR) >= nr)
1079 /* it will cause a spil */
1083 /*-----------------------------------------------------------------*/
1084 /* positionRegs - the allocator can allocate same registers to res- */
1085 /* ult and operand, if this happens make sure they are in the same */
1086 /* position as the operand otherwise chaos results */
1087 /*-----------------------------------------------------------------*/
1089 positionRegs (symbol * result, symbol * opsym)
1091 int count = min (result->nRegs, opsym->nRegs);
1092 int i, j = 0, shared = 0;
1095 /* if the result has been spilt then cannot share */
1100 /* first make sure that they actually share */
1101 for (i = 0; i < count; i++)
1103 for (j = 0; j < count; j++)
1105 if (result->regs[i] == opsym->regs[j] && i != j)
1115 regs *tmp = result->regs[i];
1116 result->regs[i] = result->regs[j];
1117 result->regs[j] = tmp;
1125 /*------------------------------------------------------------------*/
1126 /* verifyRegsAssigned - make sure an iTemp is properly initialized; */
1127 /* it should either have registers or have beed spilled. Otherwise, */
1128 /* there was an uninitialized variable, so just spill this to get */
1129 /* the operand in a valid state. */
1130 /*------------------------------------------------------------------*/
1132 verifyRegsAssigned (operand *op, iCode * ic)
1137 if (!IS_ITEMP (op)) return;
1139 sym = OP_SYMBOL (op);
1140 if (sym->isspilt) return;
1141 if (!sym->nRegs) return;
1142 if (sym->regs[0]) return;
1144 werrorfl (ic->filename, ic->lineno, W_LOCAL_NOINIT,
1145 sym->prereqv ? sym->prereqv->name : sym->name);
1151 /*-----------------------------------------------------------------*/
1152 /* serialRegAssign - serially allocate registers to the variables */
1153 /*-----------------------------------------------------------------*/
1155 serialRegAssign (eBBlock ** ebbs, int count)
1159 /* for all blocks */
1160 for (i = 0; i < count; i++) {
1164 if (ebbs[i]->noPath &&
1165 (ebbs[i]->entryLabel != entryLabel &&
1166 ebbs[i]->entryLabel != returnLabel))
1169 /* of all instructions do */
1170 for (ic = ebbs[i]->sch; ic; ic = ic->next) {
1174 // update the registers in use at the start of this icode
1175 for (reg=0; reg<mcs51_nRegs; reg++) {
1176 if (regs8051[reg].isFree) {
1177 ic->riu &= ~(1<<regs8051[reg].offset);
1179 ic->riu |= (1<<regs8051[reg].offset);
1183 /* if this is an ipop that means some live
1184 range will have to be assigned again */
1186 reassignLR (IC_LEFT (ic));
1188 /* if result is present && is a true symbol */
1189 if (IC_RESULT (ic) && ic->op != IFX &&
1190 IS_TRUE_SYMOP (IC_RESULT (ic)))
1191 OP_SYMBOL (IC_RESULT (ic))->allocreq++;
1193 /* take away registers from live
1194 ranges that end at this instruction */
1195 deassignLRs (ic, ebbs[i]);
1197 /* some don't need registers */
1198 if (SKIP_IC2 (ic) ||
1199 ic->op == JUMPTABLE ||
1203 (IC_RESULT (ic) && POINTER_SET (ic)))
1206 /* now we need to allocate registers
1207 only for the result */
1208 if (IC_RESULT (ic)) {
1209 symbol *sym = OP_SYMBOL (IC_RESULT (ic));
1215 /* if it does not need or is spilt
1216 or is already assigned to registers
1217 or will not live beyond this instructions */
1220 bitVectBitValue (_G.regAssigned, sym->key) ||
1221 sym->liveTo <= ic->seq)
1224 /* if some liverange has been spilt at the block level
1225 and this one live beyond this block then spil this
1227 if (_G.blockSpil && sym->liveTo > ebbs[i]->lSeq) {
1231 /* if trying to allocate this will cause
1232 a spill and there is nothing to spill
1233 or this one is rematerializable then
1235 willCS = willCauseSpill (sym->nRegs, sym->regType);
1236 spillable = computeSpillable (ic);
1237 if (sym->remat || (willCS && bitVectIsZero (spillable))) {
1242 /* If the live range preceeds the point of definition
1243 then ideally we must take into account registers that
1244 have been allocated after sym->liveFrom but freed
1245 before ic->seq. This is complicated, so spill this
1246 symbol instead and let fillGaps handle the allocation. */
1247 if (sym->liveFrom < ic->seq) {
1252 /* if it has a spillocation & is used less than
1253 all other live ranges then spill this */
1255 if (sym->usl.spillLoc) {
1256 symbol *leastUsed = leastUsedLR (liveRangesWith (spillable,
1257 allLRs, ebbs[i], ic));
1258 if (leastUsed && leastUsed->used > sym->used) {
1263 /* if none of the liveRanges have a spillLocation then better
1264 to spill this one than anything else already assigned to registers */
1265 if (liveRangesWith(spillable,noSpilLoc,ebbs[i],ic)) {
1266 /* if this is local to this block then we might find a block spil */
1267 if (!(sym->liveFrom >= ebbs[i]->fSeq && sym->liveTo <= ebbs[i]->lSeq)) {
1274 /* if we need ptr regs for the right side
1276 if (POINTER_GET (ic) && IS_SYMOP (IC_LEFT (ic))
1277 && getSize (OP_SYMBOL (IC_LEFT (ic))->type) <= (unsigned int) PTRSIZE) {
1281 if (IC_LEFT (ic) && IS_SYMOP (IC_LEFT (ic))
1282 && SPEC_OCLS(OP_SYMBOL (IC_LEFT (ic))->etype) == idata) {
1286 if (IC_RIGHT (ic) && IS_SYMOP (IC_RIGHT (ic))
1287 && SPEC_OCLS(OP_SYMBOL (IC_RIGHT (ic))->etype) == idata) {
1292 /* else we assign registers to it */
1293 _G.regAssigned = bitVectSetBit (_G.regAssigned, sym->key);
1294 _G.totRegAssigned = bitVectSetBit (_G.totRegAssigned, sym->key);
1296 for (j = 0; j < sym->nRegs; j++) {
1297 sym->regs[j] = NULL;
1298 if (sym->regType == REG_PTR)
1299 sym->regs[j] = getRegPtr (ic, ebbs[i], sym);
1302 if (ic->op == CAST && IS_SYMOP (IC_RIGHT (ic)))
1304 symbol * right = OP_SYMBOL (IC_RIGHT (ic));
1307 sym->regs[j] = allocThisReg (right->regs[j]);
1310 sym->regs[j] = getRegGpr (ic, ebbs[i], sym);
1313 /* if the allocation failed which means
1314 this was spilt then break */
1317 for (i=0; i < sym->nRegs ; i++ )
1318 sym->regs[i] = NULL;
1323 if (!POINTER_SET(ic) && !POINTER_GET(ic)) {
1324 /* if it shares registers with operands make sure
1325 that they are in the same position */
1326 if (IC_LEFT (ic) && IS_SYMOP (IC_LEFT (ic)) &&
1327 OP_SYMBOL (IC_LEFT (ic))->nRegs) {
1328 positionRegs (OP_SYMBOL (IC_RESULT (ic)),
1329 OP_SYMBOL (IC_LEFT (ic)));
1331 /* do the same for the right operand */
1332 if (IC_RIGHT (ic) && IS_SYMOP (IC_RIGHT (ic)) &&
1333 OP_SYMBOL (IC_RIGHT (ic))->nRegs) {
1334 positionRegs (OP_SYMBOL (IC_RESULT (ic)),
1335 OP_SYMBOL (IC_RIGHT (ic)));
1348 /* Check for and fix any problems with uninitialized operands */
1349 for (i = 0; i < count; i++)
1353 if (ebbs[i]->noPath &&
1354 (ebbs[i]->entryLabel != entryLabel &&
1355 ebbs[i]->entryLabel != returnLabel))
1358 for (ic = ebbs[i]->sch; ic; ic = ic->next)
1365 verifyRegsAssigned (IC_COND (ic), ic);
1369 if (ic->op == JUMPTABLE)
1371 verifyRegsAssigned (IC_JTCOND (ic), ic);
1375 verifyRegsAssigned (IC_RESULT (ic), ic);
1376 verifyRegsAssigned (IC_LEFT (ic), ic);
1377 verifyRegsAssigned (IC_RIGHT (ic), ic);
1382 /*-----------------------------------------------------------------*/
1383 /* fillGaps - Try to fill in the Gaps left by Pass1 */
1384 /*-----------------------------------------------------------------*/
1385 static void fillGaps()
1392 if (getenv("DISABLE_FILL_GAPS")) return;
1394 /* look for livernages that was spilt by the allocator */
1395 for (sym = hTabFirstItem(liveRanges,&key) ; sym ;
1396 sym = hTabNextItem(liveRanges,&key)) {
1401 if (!sym->spillA || !sym->clashes || sym->remat) continue ;
1403 /* find the liveRanges this one clashes with, that are
1404 still assigned to registers & mark the registers as used*/
1405 for ( i = 0 ; i < sym->clashes->size ; i ++) {
1409 if (bitVectBitValue(sym->clashes,i) == 0 || /* those that clash with this */
1410 bitVectBitValue(_G.totRegAssigned,i) == 0) /* and are still assigned to registers */
1413 clr = hTabItemWithKey(liveRanges,i);
1416 /* mark these registers as used */
1417 for (k = 0 ; k < clr->nRegs ; k++ )
1418 useReg(clr->regs[k]);
1421 if (willCauseSpill(sym->nRegs,sym->regType)) {
1422 /* NOPE :( clear all registers & and continue */
1428 for (i = 0 ; i < sym->defs->size ; i++ )
1430 if (bitVectBitValue(sym->defs,i))
1432 if (!(ic = hTabItemWithKey(iCodehTab,i)))
1439 D(printf("Atemping fillGaps on %s: [",sym->name));
1440 /* THERE IS HOPE !!!! */
1441 for (i=0; i < sym->nRegs ; i++ ) {
1442 if (sym->regType == REG_PTR)
1443 sym->regs[i] = getRegPtrNoSpil ();
1446 sym->regs[i] = NULL;
1447 if (ic && ic->op == CAST && IS_SYMOP (IC_RIGHT (ic)))
1449 symbol * right = OP_SYMBOL (IC_RIGHT (ic));
1452 sym->regs[i] = allocThisReg (right->regs[i]);
1455 sym->regs[i] = getRegGprNoSpil ();
1457 D(printf("%s ", sym->regs[i]->name));
1461 /* For all its definitions check if the registers
1462 allocated needs positioning NOTE: we can position
1463 only ONCE if more than One positioning required
1465 We may need to perform the checks twice; once to
1466 position the registers as needed, the second to
1467 verify any register repositioning is still
1471 for (pass=0; pass<2; pass++) {
1472 D(printf(" checking definitions\n"));
1473 for (i = 0 ; i < sym->defs->size ; i++ ) {
1474 if (bitVectBitValue(sym->defs,i)) {
1475 if (!(ic = hTabItemWithKey(iCodehTab,i))) continue ;
1476 D(printf(" ic->seq = %d\n", ic->seq));
1477 if (SKIP_IC(ic)) continue;
1478 assert(isSymbolEqual(sym,OP_SYMBOL(IC_RESULT(ic)))); /* just making sure */
1479 /* if left is assigned to registers */
1480 if (IS_SYMOP(IC_LEFT(ic)))
1482 D(printf(" left = "));
1483 D(printOperand(IC_LEFT(ic),NULL));
1485 if (IS_SYMOP(IC_LEFT(ic)) &&
1486 bitVectBitValue(_G.totRegAssigned,OP_SYMBOL(IC_LEFT(ic))->key)) {
1487 pdone += (positionRegs(sym,OP_SYMBOL(IC_LEFT(ic)))>0);
1489 if (IS_SYMOP(IC_RIGHT(ic)))
1491 D(printf(" right = "));
1492 D(printOperand(IC_RIGHT(ic),NULL));
1494 if (IS_SYMOP(IC_RIGHT(ic)) &&
1495 bitVectBitValue(_G.totRegAssigned,OP_SYMBOL(IC_RIGHT(ic))->key)) {
1496 pdone += (positionRegs(sym,OP_SYMBOL(IC_RIGHT(ic)))>0);
1498 D(printf(" pdone = %d\n", pdone));
1499 if (pdone > 1) break;
1502 D(printf(" checking uses\n"));
1503 for (i = 0 ; i < sym->uses->size ; i++ ) {
1504 if (bitVectBitValue(sym->uses,i)) {
1506 if (!(ic = hTabItemWithKey(iCodehTab,i))) continue ;
1507 D(printf(" ic->seq = %d\n", ic->seq));
1508 if (SKIP_IC(ic)) continue;
1509 if (POINTER_SET(ic) || POINTER_GET(ic)) continue ;
1511 /* if result is assigned to registers */
1512 if (IS_SYMOP(IC_RESULT(ic)))
1514 D(printf(" result = "));
1515 D(printOperand(IC_RESULT(ic),NULL));
1517 if (IS_SYMOP(IC_RESULT(ic)) &&
1518 bitVectBitValue(_G.totRegAssigned,OP_SYMBOL(IC_RESULT(ic))->key)) {
1519 pdone += (positionRegs(sym,OP_SYMBOL(IC_RESULT(ic)))>0);
1521 D(printf(" pdone = %d\n", pdone));
1522 if (pdone > 1) break;
1525 if (pdone == 0) break; /* second pass only if regs repositioned */
1526 if (pdone > 1) break;
1528 D(printf(" sym->regs = ["));
1529 for (i=0; i < sym->nRegs ; i++ )
1530 D(printf("%s ", sym->regs[i]->name));
1532 /* had to position more than once GIVE UP */
1534 /* UNDO all the changes we made to try this */
1536 for (i=0; i < sym->nRegs ; i++ ) {
1537 sym->regs[i] = NULL;
1540 D(printf ("Fill Gap gave up due to positioning for %s in function %s\n",sym->name, currFunc ? currFunc->name : "UNKNOWN"));
1543 D(printf ("FILLED GAP for %s in function %s\n",sym->name, currFunc ? currFunc->name : "UNKNOWN"));
1545 _G.totRegAssigned = bitVectSetBit(_G.totRegAssigned,sym->key);
1546 sym->isspilt = sym->spillA = 0 ;
1547 sym->usl.spillLoc->allocreq--;
1552 /*-----------------------------------------------------------------*/
1553 /* rUmaskForOp :- returns register mask for an operand */
1554 /*-----------------------------------------------------------------*/
1556 mcs51_rUmaskForOp (operand * op)
1562 /* only temporaries are assigned registers */
1566 sym = OP_SYMBOL (op);
1568 /* if spilt or no registers assigned to it
1570 if (sym->isspilt || !sym->nRegs)
1573 rumask = newBitVect (mcs51_nRegs);
1575 for (j = 0; j < sym->nRegs; j++)
1577 if (sym->regs[j]) /* EEP - debug */
1578 rumask = bitVectSetBit (rumask,
1579 sym->regs[j]->rIdx);
1585 /*-----------------------------------------------------------------*/
1586 /* regsUsedIniCode :- returns bit vector of registers used in iCode */
1587 /*-----------------------------------------------------------------*/
1589 regsUsedIniCode (iCode * ic)
1591 bitVect *rmask = newBitVect (mcs51_nRegs);
1593 /* do the special cases first */
1596 rmask = bitVectUnion (rmask,
1597 mcs51_rUmaskForOp (IC_COND (ic)));
1601 /* for the jumptable */
1602 if (ic->op == JUMPTABLE)
1604 rmask = bitVectUnion (rmask,
1605 mcs51_rUmaskForOp (IC_JTCOND (ic)));
1610 /* of all other cases */
1612 rmask = bitVectUnion (rmask,
1613 mcs51_rUmaskForOp (IC_LEFT (ic)));
1617 rmask = bitVectUnion (rmask,
1618 mcs51_rUmaskForOp (IC_RIGHT (ic)));
1621 rmask = bitVectUnion (rmask,
1622 mcs51_rUmaskForOp (IC_RESULT (ic)));
1628 /*-----------------------------------------------------------------*/
1629 /* createRegMask - for each instruction will determine the regsUsed */
1630 /*-----------------------------------------------------------------*/
1632 createRegMask (eBBlock ** ebbs, int count)
1636 /* for all blocks */
1637 for (i = 0; i < count; i++)
1641 if (ebbs[i]->noPath &&
1642 (ebbs[i]->entryLabel != entryLabel &&
1643 ebbs[i]->entryLabel != returnLabel))
1646 /* for all instructions */
1647 for (ic = ebbs[i]->sch; ic; ic = ic->next)
1652 if (SKIP_IC2 (ic) || !ic->rlive)
1655 /* first mark the registers used in this
1657 ic->rUsed = regsUsedIniCode (ic);
1658 _G.funcrUsed = bitVectUnion (_G.funcrUsed, ic->rUsed);
1660 /* now create the register mask for those
1661 registers that are in use : this is a
1662 super set of ic->rUsed */
1663 ic->rMask = newBitVect (mcs51_nRegs + 1);
1665 /* for all live Ranges alive at this point */
1666 for (j = 1; j < ic->rlive->size; j++)
1671 /* if not alive then continue */
1672 if (!bitVectBitValue (ic->rlive, j))
1675 /* find the live range we are interested in */
1676 if (!(sym = hTabItemWithKey (liveRanges, j)))
1678 werror (E_INTERNAL_ERROR, __FILE__, __LINE__,
1679 "createRegMask cannot find live range");
1680 fprintf(stderr, "\tmissing live range: key=%d\n", j);
1684 /* if no register assigned to it */
1685 if (!sym->nRegs || sym->isspilt)
1688 /* for all the registers allocated to it */
1689 for (k = 0; k < sym->nRegs; k++)
1692 bitVectSetBit (ic->rMask, sym->regs[k]->rIdx);
1698 /*-----------------------------------------------------------------*/
1699 /* rematStr - returns the rematerialized string for a remat var */
1700 /*-----------------------------------------------------------------*/
1702 rematStr (symbol * sym)
1705 iCode *ic = sym->rematiCode;
1710 /* if plus or minus print the right hand side */
1711 if (ic->op == '+' || ic->op == '-')
1713 sprintf (s, "0x%04x %c ", (int) operandLitValue (IC_RIGHT (ic)),
1716 ic = OP_SYMBOL (IC_LEFT (ic))->rematiCode;
1720 /* cast then continue */
1721 if (IS_CAST_ICODE(ic)) {
1722 ic = OP_SYMBOL (IC_RIGHT (ic))->rematiCode;
1725 /* we reached the end */
1726 sprintf (s, "%s", OP_SYMBOL (IC_LEFT (ic))->rname);
1733 /*-----------------------------------------------------------------*/
1734 /* regTypeNum - computes the type & number of registers required */
1735 /*-----------------------------------------------------------------*/
1737 regTypeNum (eBBlock *ebbs)
1743 /* for each live range do */
1744 for (sym = hTabFirstItem (liveRanges, &k); sym;
1745 sym = hTabNextItem (liveRanges, &k))
1748 /* if used zero times then no registers needed */
1749 if ((sym->liveTo - sym->liveFrom) == 0)
1753 /* if the live range is a temporary */
1757 /* if the type is marked as a conditional */
1758 if (sym->regType == REG_CND)
1761 /* if used in return only then we don't
1763 if (sym->ruonly || sym->accuse)
1765 if (IS_AGGREGATE (sym->type) || sym->isptr)
1766 sym->type = aggrToPtr (sym->type, FALSE);
1770 /* if the symbol has only one definition &
1771 that definition is a get_pointer */
1772 if (bitVectnBitsOn (sym->defs) == 1 &&
1773 (ic = hTabItemWithKey (iCodehTab,
1774 bitVectFirstBit (sym->defs))) &&
1776 !IS_BITVAR (sym->etype) &&
1777 (aggrToPtrDclType (operandType (IC_LEFT (ic)), FALSE) == POINTER))
1780 if (ptrPseudoSymSafe (sym, ic))
1782 ptrPseudoSymConvert (sym, ic, rematStr (OP_SYMBOL (IC_LEFT (ic))));
1786 /* if in data space or idata space then try to
1787 allocate pointer register */
1791 /* if not then we require registers */
1792 sym->nRegs = ((IS_AGGREGATE (sym->type) || sym->isptr) ?
1793 getSize (sym->type = aggrToPtr (sym->type, FALSE)) :
1794 getSize (sym->type));
1798 fprintf (stderr, "allocated more than 4 or 0 registers for type ");
1799 printTypeChain (sym->type, stderr);
1800 fprintf (stderr, "\n");
1803 /* determine the type of register required */
1804 if (sym->nRegs == 1 &&
1805 IS_PTR (sym->type) &&
1807 sym->regType = REG_PTR;
1809 sym->regType = REG_GPR;
1813 /* for the first run we don't provide */
1814 /* registers for true symbols we will */
1815 /* see how things go */
1821 /*-----------------------------------------------------------------*/
1822 /* freeAllRegs - mark all registers as free */
1823 /*-----------------------------------------------------------------*/
1829 for (i = 0; i < mcs51_nRegs; i++)
1830 regs8051[i].isFree = 1;
1833 /*-----------------------------------------------------------------*/
1834 /* deallocStackSpil - this will set the stack pointer back */
1835 /*-----------------------------------------------------------------*/
1837 DEFSETFUNC (deallocStackSpil)
1845 /*-----------------------------------------------------------------*/
1846 /* farSpacePackable - returns the packable icode for far variables */
1847 /*-----------------------------------------------------------------*/
1849 farSpacePackable (iCode * ic)
1853 /* go thru till we find a definition for the
1854 symbol on the right */
1855 for (dic = ic->prev; dic; dic = dic->prev)
1857 /* if the definition is a call then no */
1858 if ((dic->op == CALL || dic->op == PCALL) &&
1859 IC_RESULT (dic)->key == IC_RIGHT (ic)->key)
1864 /* if shift by unknown amount then not */
1865 if ((dic->op == LEFT_OP || dic->op == RIGHT_OP) &&
1866 IC_RESULT (dic)->key == IC_RIGHT (ic)->key)
1869 /* if pointer get and size > 1 */
1870 if (POINTER_GET (dic) &&
1871 getSize (aggrToPtr (operandType (IC_LEFT (dic)), FALSE)) > 1)
1874 if (POINTER_SET (dic) &&
1875 getSize (aggrToPtr (operandType (IC_RESULT (dic)), FALSE)) > 1)
1880 if (IC_COND (dic) &&
1881 IS_TRUE_SYMOP (IC_COND (dic)) &&
1882 isOperandInFarSpace (IC_COND (dic)))
1885 else if (dic->op == JUMPTABLE)
1887 if (IC_JTCOND (dic) &&
1888 IS_TRUE_SYMOP (IC_JTCOND (dic)) &&
1889 isOperandInFarSpace (IC_JTCOND (dic)))
1894 /* if any three is a true symbol in far space */
1895 if (IC_RESULT (dic) &&
1896 IS_TRUE_SYMOP (IC_RESULT (dic)) &&
1897 isOperandInFarSpace (IC_RESULT (dic)))
1900 if (IC_RIGHT (dic) &&
1901 IS_TRUE_SYMOP (IC_RIGHT (dic)) &&
1902 isOperandInFarSpace (IC_RIGHT (dic)) &&
1903 !isOperandEqual (IC_RIGHT (dic), IC_RESULT (ic)))
1906 if (IC_LEFT (dic) &&
1907 IS_TRUE_SYMOP (IC_LEFT (dic)) &&
1908 isOperandInFarSpace (IC_LEFT (dic)) &&
1909 !isOperandEqual (IC_LEFT (dic), IC_RESULT (ic)))
1913 if (isOperandEqual (IC_RIGHT (ic), IC_RESULT (dic)))
1915 if ((dic->op == LEFT_OP ||
1916 dic->op == RIGHT_OP ||
1918 IS_OP_LITERAL (IC_RIGHT (dic)))
1928 /*-----------------------------------------------------------------*/
1929 /* packRegsForAssign - register reduction for assignment */
1930 /*-----------------------------------------------------------------*/
1932 packRegsForAssign (iCode * ic, eBBlock * ebp)
1936 if (!IS_ITEMP (IC_RIGHT (ic)) ||
1937 OP_SYMBOL (IC_RIGHT (ic))->isind ||
1938 OP_LIVETO (IC_RIGHT (ic)) > ic->seq)
1943 /* if the true symbol is defined in far space or on stack
1944 then we should not since this will increase register pressure */
1945 if (isOperandInFarSpace(IC_RESULT(ic)) && !farSpacePackable(ic)) {
1949 /* find the definition of iTempNN scanning backwards if we find a
1950 a use of the true symbol in before we find the definition then
1952 for (dic = ic->prev; dic; dic = dic->prev)
1954 int crossedCall = 0;
1956 /* We can pack across a function call only if it's a local */
1957 /* variable or our parameter. Never pack global variables */
1958 /* or parameters to a function we call. */
1959 if ((dic->op == CALL || dic->op == PCALL))
1961 if (!OP_SYMBOL (IC_RESULT (ic))->ismyparm
1962 && !OP_SYMBOL (IC_RESULT (ic))->islocal)
1973 if (IS_SYMOP (IC_COND (dic)) &&
1974 (IC_COND (dic)->key == IC_RESULT (ic)->key ||
1975 IC_COND (dic)->key == IC_RIGHT (ic)->key))
1983 if (IS_TRUE_SYMOP (IC_RESULT (dic)) &&
1984 IS_OP_VOLATILE (IC_RESULT (dic)))
1990 if (IS_SYMOP (IC_RESULT (dic)) &&
1991 IC_RESULT (dic)->key == IC_RIGHT (ic)->key)
1993 if (POINTER_SET (dic))
1999 if (IS_SYMOP (IC_RIGHT (dic)) &&
2000 (IC_RIGHT (dic)->key == IC_RESULT (ic)->key ||
2001 IC_RIGHT (dic)->key == IC_RIGHT (ic)->key))
2007 if (IS_SYMOP (IC_LEFT (dic)) &&
2008 (IC_LEFT (dic)->key == IC_RESULT (ic)->key ||
2009 IC_LEFT (dic)->key == IC_RIGHT (ic)->key))
2015 if (IS_SYMOP (IC_RESULT (dic)) &&
2016 IC_RESULT (dic)->key == IC_RESULT (ic)->key)
2032 return 0; /* did not find */
2034 /* if assignment then check that right is not a bit */
2035 if (ASSIGNMENT (ic) && !POINTER_SET (ic))
2037 sym_link *etype = operandType (IC_RESULT (dic));
2038 if (IS_BITFIELD (etype))
2040 /* if result is a bit too then it's ok */
2041 etype = operandType (IC_RESULT (ic));
2042 if (!IS_BITFIELD (etype))
2049 /* if assignment then check that right is not a bit */
2050 if (ASSIGNMENT (dic) && !POINTER_SET (dic))
2052 sym_link *etype = operandType (IC_RIGHT (dic));
2053 if (IS_BITFIELD (etype))
2055 /* if result is a bit too then it's ok */
2056 etype = operandType (IC_RESULT (dic));
2057 if (!IS_BITFIELD (etype))
2062 /* if the result is on stack or iaccess then it must be
2063 the same atleast one of the operands */
2064 if (OP_SYMBOL (IC_RESULT (ic))->onStack ||
2065 OP_SYMBOL (IC_RESULT (ic))->iaccess)
2068 /* the operation has only one symbol
2069 operator then we can pack */
2070 if ((IC_LEFT (dic) && !IS_SYMOP (IC_LEFT (dic))) ||
2071 (IC_RIGHT (dic) && !IS_SYMOP (IC_RIGHT (dic))))
2074 if (!((IC_LEFT (dic) &&
2075 IC_RESULT (ic)->key == IC_LEFT (dic)->key) ||
2077 IC_RESULT (ic)->key == IC_RIGHT (dic)->key)))
2081 /* found the definition */
2082 /* replace the result with the result of */
2083 /* this assignment and remove this assignment */
2084 bitVectUnSetBit(OP_SYMBOL(IC_RESULT(dic))->defs,dic->key);
2085 ReplaceOpWithCheaperOp(&IC_RESULT (dic), IC_RESULT (ic));
2087 if (IS_ITEMP (IC_RESULT (dic)) && OP_SYMBOL (IC_RESULT (dic))->liveFrom > dic->seq)
2089 OP_SYMBOL (IC_RESULT (dic))->liveFrom = dic->seq;
2091 // TODO: and the otherway around?
2093 /* delete from liverange table also
2094 delete from all the points inbetween and the new
2096 for (sic = dic; sic != ic; sic = sic->next)
2098 bitVectUnSetBit (sic->rlive, IC_RESULT (ic)->key);
2099 if (IS_ITEMP (IC_RESULT (dic)))
2100 bitVectSetBit (sic->rlive, IC_RESULT (dic)->key);
2103 remiCodeFromeBBlock (ebp, ic);
2104 bitVectUnSetBit(OP_SYMBOL(IC_RESULT(ic))->defs,ic->key);
2105 hTabDeleteItem (&iCodehTab, ic->key, ic, DELETE_ITEM, NULL);
2106 OP_DEFS(IC_RESULT (dic))=bitVectSetBit (OP_DEFS (IC_RESULT (dic)), dic->key);
2110 /*------------------------------------------------------------------*/
2111 /* findAssignToSym : scanning backwards looks for first assig found */
2112 /*------------------------------------------------------------------*/
2114 findAssignToSym (operand * op, iCode * ic)
2118 /* This routine is used to find sequences like
2120 ...; (intervening ops don't use iTempAA or modify FOO)
2121 blah = blah + iTempAA;
2123 and eliminate the use of iTempAA, freeing up its register for
2127 for (dic = ic->prev; dic; dic = dic->prev)
2130 /* if definition by assignment */
2131 if (dic->op == '=' &&
2132 !POINTER_SET (dic) &&
2133 IC_RESULT (dic)->key == op->key
2134 /* && IS_TRUE_SYMOP(IC_RIGHT(dic)) */
2136 break; /* found where this temp was defined */
2138 /* if we find an usage then we cannot delete it */
2142 if (IC_COND (dic) && IC_COND (dic)->key == op->key)
2145 else if (dic->op == JUMPTABLE)
2147 if (IC_JTCOND (dic) && IC_JTCOND (dic)->key == op->key)
2152 if (IC_LEFT (dic) && IC_LEFT (dic)->key == op->key)
2155 if (IC_RIGHT (dic) && IC_RIGHT (dic)->key == op->key)
2158 if (POINTER_SET (dic) && IC_RESULT (dic)->key == op->key)
2164 return NULL; /* didn't find any assignment to op */
2166 /* we are interested only if defined in far space */
2167 /* or in stack space in case of + & - */
2169 /* if assigned to a non-symbol then don't repack regs */
2170 if (!IS_SYMOP (IC_RIGHT (dic)))
2173 /* if the symbol is volatile then we should not */
2174 if (isOperandVolatile (IC_RIGHT (dic), TRUE))
2176 /* XXX TODO --- should we be passing FALSE to isOperandVolatile()?
2177 What does it mean for an iTemp to be volatile, anyway? Passing
2178 TRUE is more cautious but may prevent possible optimizations */
2180 /* if the symbol is in far space then we should not */
2181 if (isOperandInFarSpace (IC_RIGHT (dic)))
2184 /* for + & - operations make sure that
2185 if it is on the stack it is the same
2186 as one of the three operands */
2187 if ((ic->op == '+' || ic->op == '-') &&
2188 OP_SYMBOL (IC_RIGHT (dic))->onStack)
2191 if (IC_RESULT (ic)->key != IC_RIGHT (dic)->key &&
2192 IC_LEFT (ic)->key != IC_RIGHT (dic)->key &&
2193 IC_RIGHT (ic)->key != IC_RIGHT (dic)->key)
2197 /* now make sure that the right side of dic
2198 is not defined between ic & dic */
2201 iCode *sic = dic->next;
2203 for (; sic != ic; sic = sic->next)
2204 if (IC_RESULT (sic) &&
2205 IC_RESULT (sic)->key == IC_RIGHT (dic)->key)
2212 /*-----------------------------------------------------------------*/
2213 /* reassignAliasedSym - used by packRegsForSupport to replace */
2214 /* redundant iTemp with equivalent symbol */
2215 /*-----------------------------------------------------------------*/
2217 reassignAliasedSym (eBBlock *ebp, iCode *assignment, iCode *use, operand *op)
2220 unsigned oldSymKey, newSymKey;
2222 oldSymKey = op->key;
2223 newSymKey = IC_RIGHT(assignment)->key;
2225 /* only track live ranges of compiler-generated temporaries */
2226 if (!IS_ITEMP(IC_RIGHT(assignment)))
2229 /* update the live-value bitmaps */
2230 for (ic = assignment; ic != use; ic = ic->next) {
2231 bitVectUnSetBit (ic->rlive, oldSymKey);
2233 ic->rlive = bitVectSetBit (ic->rlive, newSymKey);
2236 /* update the sym of the used operand */
2237 OP_SYMBOL(op) = OP_SYMBOL(IC_RIGHT(assignment));
2238 op->key = OP_SYMBOL(op)->key;
2239 OP_SYMBOL(op)->accuse = 0;
2241 /* update the sym's liverange */
2242 if ( OP_LIVETO(op) < ic->seq )
2243 setToRange(op, ic->seq, FALSE);
2245 /* remove the assignment iCode now that its result is unused */
2246 remiCodeFromeBBlock (ebp, assignment);
2247 bitVectUnSetBit(OP_SYMBOL(IC_RESULT(assignment))->defs, assignment->key);
2248 hTabDeleteItem (&iCodehTab, assignment->key, assignment, DELETE_ITEM, NULL);
2252 /*-----------------------------------------------------------------*/
2253 /* packRegsForSupport :- reduce some registers for support calls */
2254 /*-----------------------------------------------------------------*/
2256 packRegsForSupport (iCode * ic, eBBlock * ebp)
2260 /* for the left & right operand :- look to see if the
2261 left was assigned a true symbol in far space in that
2262 case replace them */
2264 if (IS_ITEMP (IC_LEFT (ic)) &&
2265 OP_SYMBOL (IC_LEFT (ic))->liveTo <= ic->seq)
2267 dic = findAssignToSym (IC_LEFT (ic), ic);
2271 /* found it we need to remove it from the block */
2272 reassignAliasedSym (ebp, dic, ic, IC_LEFT(ic));
2277 /* do the same for the right operand */
2278 if (IS_ITEMP (IC_RIGHT (ic)) &&
2279 OP_SYMBOL (IC_RIGHT (ic))->liveTo <= ic->seq)
2281 iCode *dic = findAssignToSym (IC_RIGHT (ic), ic);
2285 /* if this is a subtraction & the result
2286 is a true symbol in far space then don't pack */
2287 if (ic->op == '-' && IS_TRUE_SYMOP (IC_RESULT (dic)))
2289 sym_link *etype = getSpec (operandType (IC_RESULT (dic)));
2290 if (IN_FARSPACE (SPEC_OCLS (etype)))
2293 /* found it we need to remove it from the
2295 reassignAliasedSym (ebp, dic, ic, IC_RIGHT(ic));
2304 #define IS_OP_RUONLY(x) (x && IS_SYMOP(x) && OP_SYMBOL(x)->ruonly)
2307 /*-----------------------------------------------------------------*/
2308 /* packRegsForOneuse : - will reduce some registers for single Use */
2309 /*-----------------------------------------------------------------*/
2311 packRegsForOneuse (iCode * ic, operand * op, eBBlock * ebp)
2315 /* if returning a literal then do nothing */
2319 /* if rematerializable or already return use then do nothing */
2320 if (OP_SYMBOL(op)->remat || OP_SYMBOL(op)->ruonly)
2323 /* only upto 2 bytes since we cannot predict
2324 the usage of b, & acc */
2325 if (getSize (operandType (op)) > (fReturnSizeMCS51 - 2))
2328 if (ic->op != RETURN &&
2330 !POINTER_SET (ic) &&
2334 if (ic->op == SEND && ic->argreg != 1) return NULL;
2336 /* this routine will mark the a symbol as used in one
2337 instruction use only && if the defintion is local
2338 (ie. within the basic block) && has only one definition &&
2339 that definiion is either a return value from a
2340 function or does not contain any variables in
2342 if (bitVectnBitsOn (OP_USES (op)) > 1)
2345 /* if it has only one defintion */
2346 if (bitVectnBitsOn (OP_DEFS (op)) > 1)
2347 return NULL; /* has more than one definition */
2349 /* get that definition */
2351 hTabItemWithKey (iCodehTab,
2352 bitVectFirstBit (OP_DEFS (op)))))
2355 /* if that only usage is a cast */
2356 if (dic->op == CAST) {
2357 /* to a bigger type */
2358 if (getSize(OP_SYM_TYPE(IC_RESULT(dic))) >
2359 getSize(OP_SYM_TYPE(IC_RIGHT(dic)))) {
2360 /* than we can not, since we cannot predict the usage of b & acc */
2365 /* found the definition now check if it is local */
2366 if (dic->seq < ebp->fSeq ||
2367 dic->seq > ebp->lSeq)
2368 return NULL; /* non-local */
2370 /* now check if it is the return from
2372 if (dic->op == CALL || dic->op == PCALL)
2374 if (ic->op != SEND && ic->op != RETURN &&
2375 !POINTER_SET(ic) && !POINTER_GET(ic))
2377 OP_SYMBOL (op)->ruonly = 1;
2383 /* otherwise check that the definition does
2384 not contain any symbols in far space */
2385 if (isOperandInFarSpace (IC_LEFT (dic)) ||
2386 isOperandInFarSpace (IC_RIGHT (dic)) ||
2387 IS_OP_RUONLY (IC_LEFT (ic)) ||
2388 IS_OP_RUONLY (IC_RIGHT (ic)))
2393 /* if pointer set then make sure the pointer
2395 if (POINTER_SET (dic) &&
2396 !IS_DATA_PTR (aggrToPtr (operandType (IC_RESULT (dic)), FALSE)))
2399 if (POINTER_GET (dic) &&
2400 !IS_DATA_PTR (aggrToPtr (operandType (IC_LEFT (dic)), FALSE)))
2404 /* Make sure no overlapping liverange is already assigned to DPTR */
2405 if (OP_SYMBOL(op)->clashes)
2410 for (i = 0 ; i < OP_SYMBOL(op)->clashes->size ; i++ )
2412 if (bitVectBitValue(OP_SYMBOL(op)->clashes,i))
2414 sym = hTabItemWithKey(liveRanges,i);
2423 /* also make sure the intervenening instructions
2424 don't have any thing in far space */
2425 for (dic = dic->next; dic && dic != ic && sic != ic; dic = dic->next)
2428 /* if there is an intervening function call then no */
2429 if (dic->op == CALL || dic->op == PCALL)
2431 /* if pointer set then make sure the pointer
2433 if (POINTER_SET (dic) &&
2434 !IS_DATA_PTR (aggrToPtr (operandType (IC_RESULT (dic)), FALSE)))
2437 if (POINTER_GET (dic) &&
2438 !IS_DATA_PTR (aggrToPtr (operandType (IC_LEFT (dic)), FALSE)))
2441 /* if address of & the result is remat the okay */
2442 if (dic->op == ADDRESS_OF &&
2443 OP_SYMBOL (IC_RESULT (dic))->remat)
2446 /* if operand has size of three or more & this
2447 operation is a '*','/' or '%' then 'b' may
2449 if ((dic->op == '%' || dic->op == '/' || dic->op == '*') &&
2450 getSize (operandType (op)) >= 3)
2453 /* if left or right or result is in far space */
2454 if (isOperandInFarSpace (IC_LEFT (dic)) ||
2455 isOperandInFarSpace (IC_RIGHT (dic)) ||
2456 isOperandInFarSpace (IC_RESULT (dic)) ||
2457 IS_OP_RUONLY (IC_LEFT (dic)) ||
2458 IS_OP_RUONLY (IC_RIGHT (dic)) ||
2459 IS_OP_RUONLY (IC_RESULT (dic)))
2463 /* if left or right or result is on stack */
2464 if (isOperandOnStack(IC_LEFT(dic)) ||
2465 isOperandOnStack(IC_RIGHT(dic)) ||
2466 isOperandOnStack(IC_RESULT(dic))) {
2471 OP_SYMBOL (op)->ruonly = 1;
2475 /*-----------------------------------------------------------------*/
2476 /* isBitwiseOptimizable - requirements of JEAN LOUIS VERN */
2477 /*-----------------------------------------------------------------*/
2479 isBitwiseOptimizable (iCode * ic)
2481 sym_link *ltype = getSpec (operandType (IC_LEFT (ic)));
2482 sym_link *rtype = getSpec (operandType (IC_RIGHT (ic)));
2484 /* bitwise operations are considered optimizable
2485 under the following conditions (Jean-Louis VERN)
2497 if (IS_LITERAL(rtype) ||
2498 (IS_BITVAR (ltype) && IN_BITSPACE (SPEC_OCLS (ltype))))
2504 /*-----------------------------------------------------------------*/
2505 /* isCommutativeOp - tests whether this op cares what order its */
2506 /* operands are in */
2507 /*-----------------------------------------------------------------*/
2508 bool isCommutativeOp(unsigned int op)
2510 if (op == '+' || op == '*' || op == EQ_OP ||
2511 op == '^' || op == '|' || op == BITWISEAND)
2517 /*-----------------------------------------------------------------*/
2518 /* operandUsesAcc - determines whether the code generated for this */
2519 /* operand will have to use the accumulator */
2520 /*-----------------------------------------------------------------*/
2521 bool operandUsesAcc(operand *op)
2527 symbol *sym = OP_SYMBOL(op);
2531 return TRUE; /* duh! */
2533 if (IN_STACK(sym->etype) || sym->onStack ||
2534 (SPIL_LOC(op) && SPIL_LOC(op)->onStack))
2535 return TRUE; /* acc is used to calc stack offset */
2540 sym = SPIL_LOC(op); /* if spilled, look at spill location */
2542 return FALSE; /* more checks? */
2546 symspace = SPEC_OCLS(sym->etype);
2548 if (sym->iaccess && symspace->paged)
2549 return TRUE; /* must fetch paged indirect sym via accumulator */
2551 if (IN_BITSPACE(symspace))
2552 return TRUE; /* fetching bit vars uses the accumulator */
2554 if (IN_FARSPACE(symspace) || IN_CODESPACE(symspace))
2555 return TRUE; /* fetched via accumulator and dptr */
2561 /*-----------------------------------------------------------------*/
2562 /* packRegsForAccUse - pack registers for acc use */
2563 /*-----------------------------------------------------------------*/
2565 packRegsForAccUse (iCode * ic)
2569 /* if this is an aggregate, e.g. a one byte char array */
2570 if (IS_AGGREGATE(operandType(IC_RESULT(ic)))) {
2574 /* if we are calling a reentrant function that has stack parameters */
2575 if (ic->op == CALL &&
2576 IFFUNC_ISREENT(operandType(IC_LEFT(ic))) &&
2577 FUNC_HASSTACKPARM(operandType(IC_LEFT(ic))))
2580 if (ic->op == PCALL &&
2581 IFFUNC_ISREENT(operandType(IC_LEFT(ic))->next) &&
2582 FUNC_HASSTACKPARM(operandType(IC_LEFT(ic))->next))
2585 /* if + or - then it has to be one byte result */
2586 if ((ic->op == '+' || ic->op == '-')
2587 && getSize (operandType (IC_RESULT (ic))) > 1)
2590 /* if shift operation make sure right side is not a literal */
2591 if (ic->op == RIGHT_OP &&
2592 (isOperandLiteral (IC_RIGHT (ic)) ||
2593 getSize (operandType (IC_RESULT (ic))) > 1))
2596 if (ic->op == LEFT_OP &&
2597 (isOperandLiteral (IC_RIGHT (ic)) ||
2598 getSize (operandType (IC_RESULT (ic))) > 1))
2601 if (IS_BITWISE_OP (ic) &&
2602 getSize (operandType (IC_RESULT (ic))) > 1)
2606 /* has only one definition */
2607 if (bitVectnBitsOn (OP_DEFS (IC_RESULT (ic))) > 1)
2610 /* has only one use */
2611 if (bitVectnBitsOn (OP_USES (IC_RESULT (ic))) > 1)
2614 /* and the usage immediately follows this iCode */
2615 if (!(uic = hTabItemWithKey (iCodehTab,
2616 bitVectFirstBit (OP_USES (IC_RESULT (ic))))))
2619 if (ic->next != uic)
2622 /* if it is a conditional branch then we definitely can */
2626 if (uic->op == JUMPTABLE)
2629 if (POINTER_SET (uic) &&
2630 getSize (aggrToPtr (operandType (IC_RESULT (uic)), FALSE)) > 1)
2633 /* if the usage is not is an assignment
2634 or an arithmetic / bitwise / shift operation then not */
2635 if (uic->op != '=' &&
2636 !IS_ARITHMETIC_OP (uic) &&
2637 !IS_BITWISE_OP (uic) &&
2638 uic->op != LEFT_OP &&
2639 uic->op != RIGHT_OP)
2642 /* if used in ^ operation then make sure right is not a
2643 literal (WIML: Why is this?) */
2644 if (uic->op == '^' && isOperandLiteral (IC_RIGHT (uic)))
2647 /* if shift operation make sure right side is not a literal */
2648 /* WIML: Why is this? */
2649 if (uic->op == RIGHT_OP &&
2650 (isOperandLiteral (IC_RIGHT (uic)) ||
2651 getSize (operandType (IC_RESULT (uic))) > 1))
2653 if (uic->op == LEFT_OP &&
2654 (isOperandLiteral (IC_RIGHT (uic)) ||
2655 getSize (operandType (IC_RESULT (uic))) > 1))
2658 /* make sure that the result of this icode is not on the
2659 stack, since acc is used to compute stack offset */
2661 if (IS_TRUE_SYMOP (IC_RESULT (uic)) &&
2662 OP_SYMBOL (IC_RESULT (uic))->onStack)
2665 if (isOperandOnStack(IC_RESULT(uic)))
2669 /* if the usage has only one operand then we can */
2670 if (IC_LEFT (uic) == NULL ||
2671 IC_RIGHT (uic) == NULL)
2674 /* if the other operand uses the accumulator then we cannot */
2675 if ( (IC_LEFT(uic)->key == IC_RESULT(ic)->key &&
2676 operandUsesAcc(IC_RIGHT(uic))) ||
2677 (IC_RIGHT(uic)->key == IC_RESULT(ic)->key &&
2678 operandUsesAcc(IC_LEFT(uic))) )
2681 /* make sure this is on the left side if not commutative */
2682 /* except for '-', which has been written to be able to
2683 handle reversed operands */
2684 if (!(isCommutativeOp(ic->op) || ic->op == '-') &&
2685 IC_LEFT (uic)->key != IC_RESULT (ic)->key)
2689 // this is too dangerous and need further restrictions
2692 /* if one of them is a literal then we can */
2693 if ((IC_LEFT (uic) && IS_OP_LITERAL (IC_LEFT (uic))) ||
2694 (IC_RIGHT (uic) && IS_OP_LITERAL (IC_RIGHT (uic))))
2696 OP_SYMBOL (IC_RESULT (ic))->accuse = 1;
2702 OP_SYMBOL (IC_RESULT (ic))->accuse = 1;
2706 /*-----------------------------------------------------------------*/
2707 /* packForPush - hueristics to reduce iCode for pushing */
2708 /*-----------------------------------------------------------------*/
2710 packForPush (iCode * ic, eBBlock ** ebpp, int blockno)
2714 struct eBBlock * ebp=ebpp[blockno];
2716 if (ic->op != IPUSH || !IS_ITEMP (IC_LEFT (ic)))
2719 /* must have only definition & one usage */
2720 if (bitVectnBitsOn (OP_DEFS (IC_LEFT (ic))) != 1 ||
2721 bitVectnBitsOn (OP_USES (IC_LEFT (ic))) != 1)
2724 /* find the definition */
2725 if (!(dic = hTabItemWithKey (iCodehTab,
2726 bitVectFirstBit (OP_DEFS (IC_LEFT (ic))))))
2729 if (dic->op != '=' || POINTER_SET (dic))
2732 if (dic->seq < ebp->fSeq) { // Evelyn did this
2734 for (i=0; i<blockno; i++) {
2735 if (dic->seq >= ebpp[i]->fSeq && dic->seq <= ebpp[i]->lSeq) {
2740 wassert (i!=blockno); // no way to recover from here
2743 if (IS_SYMOP(IC_RIGHT(dic))) {
2744 /* make sure the right side does not have any definitions
2746 dbv = OP_DEFS(IC_RIGHT(dic));
2747 for (lic = ic; lic && lic != dic ; lic = lic->prev) {
2748 if (bitVectBitValue(dbv,lic->key))
2751 /* make sure they have the same type */
2752 if (IS_SPEC(operandType(IC_LEFT(ic))))
2754 sym_link *itype=operandType(IC_LEFT(ic));
2755 sym_link *ditype=operandType(IC_RIGHT(dic));
2757 if (SPEC_USIGN(itype)!=SPEC_USIGN(ditype) ||
2758 SPEC_LONG(itype)!=SPEC_LONG(ditype))
2761 /* extend the live range of replaced operand if needed */
2762 if (OP_SYMBOL(IC_RIGHT(dic))->liveTo < ic->seq) {
2763 OP_SYMBOL(IC_RIGHT(dic))->liveTo = ic->seq;
2765 bitVectUnSetBit(OP_SYMBOL(IC_RESULT(dic))->defs,dic->key);
2768 /* we now we know that it has one & only one def & use
2769 and the that the definition is an assignment */
2770 ReplaceOpWithCheaperOp(&IC_LEFT (ic), IC_RIGHT (dic));
2771 remiCodeFromeBBlock (ebp, dic);
2772 hTabDeleteItem (&iCodehTab, dic->key, dic, DELETE_ITEM, NULL);
2775 /*-----------------------------------------------------------------*/
2776 /* packRegisters - does some transformations to reduce register */
2778 /*-----------------------------------------------------------------*/
2780 packRegisters (eBBlock ** ebpp, int blockno)
2784 eBBlock *ebp=ebpp[blockno];
2791 /* look for assignments of the form */
2792 /* iTempNN = TRueSym (someoperation) SomeOperand */
2794 /* TrueSym := iTempNN:1 */
2795 for (ic = ebp->sch; ic; ic = ic->next)
2797 /* find assignment of the form TrueSym := iTempNN:1 */
2798 if (ic->op == '=' && !POINTER_SET (ic))
2799 change += packRegsForAssign (ic, ebp);
2806 for (ic = ebp->sch; ic; ic = ic->next)
2808 /* if this is an itemp & result of an address of a true sym
2809 then mark this as rematerialisable */
2810 if (ic->op == ADDRESS_OF &&
2811 IS_ITEMP (IC_RESULT (ic)) &&
2812 IS_TRUE_SYMOP (IC_LEFT (ic)) &&
2813 bitVectnBitsOn (OP_DEFS (IC_RESULT (ic))) == 1 &&
2814 !OP_SYMBOL (IC_LEFT (ic))->onStack)
2817 OP_SYMBOL (IC_RESULT (ic))->remat = 1;
2818 OP_SYMBOL (IC_RESULT (ic))->rematiCode = ic;
2819 OP_SYMBOL (IC_RESULT (ic))->usl.spillLoc = NULL;
2823 /* if straight assignment then carry remat flag if
2824 this is the only definition */
2825 if (ic->op == '=' &&
2826 !POINTER_SET (ic) &&
2827 IS_SYMOP (IC_RIGHT (ic)) &&
2828 OP_SYMBOL (IC_RIGHT (ic))->remat &&
2829 !IS_CAST_ICODE(OP_SYMBOL (IC_RIGHT (ic))->rematiCode) &&
2830 bitVectnBitsOn (OP_SYMBOL (IC_RESULT (ic))->defs) <= 1)
2833 OP_SYMBOL (IC_RESULT (ic))->remat =
2834 OP_SYMBOL (IC_RIGHT (ic))->remat;
2835 OP_SYMBOL (IC_RESULT (ic))->rematiCode =
2836 OP_SYMBOL (IC_RIGHT (ic))->rematiCode;
2839 /* if cast to a generic pointer & the pointer being
2840 cast is remat, then we can remat this cast as well */
2841 if (ic->op == CAST &&
2842 IS_SYMOP(IC_RIGHT(ic)) &&
2843 OP_SYMBOL(IC_RIGHT(ic))->remat &&
2844 bitVectnBitsOn (OP_DEFS (IC_RESULT (ic))) == 1) {
2845 sym_link *to_type = operandType(IC_LEFT(ic));
2846 sym_link *from_type = operandType(IC_RIGHT(ic));
2847 if (IS_GENPTR(to_type) && IS_PTR(from_type)) {
2848 OP_SYMBOL (IC_RESULT (ic))->remat = 1;
2849 OP_SYMBOL (IC_RESULT (ic))->rematiCode = ic;
2850 OP_SYMBOL (IC_RESULT (ic))->usl.spillLoc = NULL;
2854 /* if this is a +/- operation with a rematerizable
2855 then mark this as rematerializable as well */
2856 if ((ic->op == '+' || ic->op == '-') &&
2857 (IS_SYMOP (IC_LEFT (ic)) &&
2858 IS_ITEMP (IC_RESULT (ic)) &&
2859 IS_OP_LITERAL (IC_RIGHT (ic))) &&
2860 OP_SYMBOL (IC_LEFT (ic))->remat &&
2861 (!IS_SYMOP (IC_RIGHT (ic)) || !IS_CAST_ICODE(OP_SYMBOL (IC_RIGHT (ic))->rematiCode)) &&
2862 bitVectnBitsOn (OP_DEFS (IC_RESULT (ic))) == 1)
2864 OP_SYMBOL (IC_RESULT (ic))->remat = 1;
2865 OP_SYMBOL (IC_RESULT (ic))->rematiCode = ic;
2866 OP_SYMBOL (IC_RESULT (ic))->usl.spillLoc = NULL;
2869 /* mark the pointer usages */
2870 if (POINTER_SET (ic))
2871 OP_SYMBOL (IC_RESULT (ic))->uptr = 1;
2873 if (POINTER_GET (ic) &&
2874 IS_SYMOP(IC_LEFT (ic)))
2875 OP_SYMBOL (IC_LEFT (ic))->uptr = 1;
2879 /* if we are using a symbol on the stack
2880 then we should say mcs51_ptrRegReq */
2881 if (options.useXstack && ic->parmPush
2882 && (ic->op == IPUSH || ic->op == IPOP))
2884 if (ic->op == IFX && IS_SYMOP (IC_COND (ic)))
2885 mcs51_ptrRegReq += ((OP_SYMBOL (IC_COND (ic))->onStack ||
2886 OP_SYMBOL (IC_COND (ic))->iaccess ||
2887 SPEC_OCLS(OP_SYMBOL (IC_COND (ic))->etype) == idata) ? 1 : 0);
2888 else if (ic->op == JUMPTABLE && IS_SYMOP (IC_JTCOND (ic)))
2889 mcs51_ptrRegReq += ((OP_SYMBOL (IC_JTCOND (ic))->onStack ||
2890 OP_SYMBOL (IC_JTCOND (ic))->iaccess ||
2891 SPEC_OCLS(OP_SYMBOL (IC_JTCOND (ic))->etype) == idata) ? 1 : 0);
2894 if (IS_SYMOP (IC_LEFT (ic)))
2895 mcs51_ptrRegReq += ((OP_SYMBOL (IC_LEFT (ic))->onStack ||
2896 OP_SYMBOL (IC_LEFT (ic))->iaccess ||
2897 SPEC_OCLS(OP_SYMBOL (IC_LEFT (ic))->etype) == idata) ? 1 : 0);
2898 if (IS_SYMOP (IC_RIGHT (ic)))
2899 mcs51_ptrRegReq += ((OP_SYMBOL (IC_RIGHT (ic))->onStack ||
2900 OP_SYMBOL (IC_RIGHT (ic))->iaccess ||
2901 SPEC_OCLS(OP_SYMBOL (IC_RIGHT (ic))->etype) == idata) ? 1 : 0);
2902 if (IS_SYMOP (IC_RESULT (ic)))
2903 mcs51_ptrRegReq += ((OP_SYMBOL (IC_RESULT (ic))->onStack ||
2904 OP_SYMBOL (IC_RESULT (ic))->iaccess ||
2905 SPEC_OCLS(OP_SYMBOL (IC_RESULT (ic))->etype) == idata) ? 1 : 0);
2906 if (POINTER_GET (ic) && IS_SYMOP (IC_LEFT (ic))
2907 && getSize (OP_SYMBOL (IC_LEFT (ic))->type) <= (unsigned int) PTRSIZE)
2909 if (POINTER_SET (ic) && IS_SYMOP (IC_RESULT (ic))
2910 && getSize (OP_SYMBOL (IC_RESULT (ic))->type) <= (unsigned int) PTRSIZE)
2915 /* if the condition of an if instruction
2916 is defined in the previous instruction and
2917 this is the only usage then
2918 mark the itemp as a conditional */
2919 if ((IS_CONDITIONAL (ic) ||
2920 (IS_BITWISE_OP(ic) && isBitwiseOptimizable (ic)) ||
2921 (POINTER_GET (ic) && getSize (operandType (IC_RESULT (ic))) <=1)) &&
2922 ic->next && ic->next->op == IFX &&
2923 bitVectnBitsOn (OP_USES(IC_RESULT(ic)))==1 &&
2924 isOperandEqual (IC_RESULT (ic), IC_COND (ic->next)) &&
2925 OP_SYMBOL (IC_RESULT (ic))->liveTo <= ic->next->seq)
2927 OP_SYMBOL (IC_RESULT (ic))->regType = REG_CND;
2931 /* if the condition of an if instruction
2932 is defined in the previous GET_POINTER instruction and
2933 this is the only usage then
2934 mark the itemp as accumulator use */
2935 if ((POINTER_GET (ic) && getSize (operandType (IC_RESULT (ic))) <=1) &&
2936 ic->next && ic->next->op == IFX &&
2937 bitVectnBitsOn (OP_USES(IC_RESULT(ic)))==1 &&
2938 isOperandEqual (IC_RESULT (ic), IC_COND (ic->next)) &&
2939 OP_SYMBOL (IC_RESULT (ic))->liveTo <= ic->next->seq)
2941 OP_SYMBOL (IC_RESULT (ic))->accuse = 1;
2945 /* reduce for support function calls */
2946 if (ic->supportRtn || ic->op == '+' || ic->op == '-')
2947 packRegsForSupport (ic, ebp);
2949 /* some cases the redundant moves can
2950 can be eliminated for return statements */
2951 if ((ic->op == RETURN || (ic->op == SEND && ic->argreg == 1)) &&
2952 !isOperandInFarSpace (IC_LEFT (ic)) &&
2953 options.model == MODEL_SMALL) {
2954 packRegsForOneuse (ic, IC_LEFT (ic), ebp);
2957 /* if pointer set & left has a size more than
2958 one and right is not in far space */
2959 if (POINTER_SET (ic) &&
2960 !isOperandInFarSpace (IC_RIGHT (ic)) &&
2961 !OP_SYMBOL (IC_RESULT (ic))->remat &&
2962 !IS_OP_RUONLY (IC_RIGHT (ic)) &&
2963 getSize (aggrToPtr (operandType (IC_RESULT (ic)), FALSE)) > 1)
2964 packRegsForOneuse (ic, IC_RESULT (ic), ebp);
2966 /* if pointer get */
2967 if (POINTER_GET (ic) &&
2968 IS_SYMOP (IC_LEFT (ic)) &&
2969 !isOperandInFarSpace (IC_RESULT (ic)) &&
2970 !OP_SYMBOL (IC_LEFT (ic))->remat &&
2971 !IS_OP_RUONLY (IC_RESULT (ic)) &&
2972 getSize (aggrToPtr (operandType (IC_LEFT (ic)), FALSE)) > 1)
2973 packRegsForOneuse (ic, IC_LEFT (ic), ebp);
2976 /* if this is cast for intergral promotion then
2977 check if only use of the definition of the
2978 operand being casted/ if yes then replace
2979 the result of that arithmetic operation with
2980 this result and get rid of the cast */
2983 sym_link *fromType = operandType (IC_RIGHT (ic));
2984 sym_link *toType = operandType (IC_LEFT (ic));
2986 if (IS_INTEGRAL (fromType) && IS_INTEGRAL (toType) &&
2987 getSize (fromType) != getSize (toType) &&
2988 SPEC_USIGN (fromType) == SPEC_USIGN (toType))
2991 iCode *dic = packRegsForOneuse (ic, IC_RIGHT (ic), ebp);
2994 if (IS_ARITHMETIC_OP (dic))
2996 bitVectUnSetBit(OP_SYMBOL(IC_RESULT(dic))->defs,dic->key);
2997 ReplaceOpWithCheaperOp(&IC_RESULT (dic), IC_RESULT (ic));
2998 remiCodeFromeBBlock (ebp, ic);
2999 bitVectUnSetBit(OP_SYMBOL(IC_RESULT(ic))->defs,ic->key);
3000 hTabDeleteItem (&iCodehTab, ic->key, ic, DELETE_ITEM, NULL);
3001 OP_DEFS(IC_RESULT (dic))=bitVectSetBit (OP_DEFS (IC_RESULT (dic)), dic->key);
3005 OP_SYMBOL (IC_RIGHT (ic))->ruonly = 0;
3011 /* if the type from and type to are the same
3012 then if this is the only use then packit */
3013 if (compareType (operandType (IC_RIGHT (ic)),
3014 operandType (IC_LEFT (ic))) == 1)
3016 iCode *dic = packRegsForOneuse (ic, IC_RIGHT (ic), ebp);
3019 bitVectUnSetBit(OP_SYMBOL(IC_RESULT(dic))->defs,dic->key);
3020 ReplaceOpWithCheaperOp(&IC_RESULT (dic), IC_RESULT (ic));
3021 remiCodeFromeBBlock (ebp, ic);
3022 bitVectUnSetBit(OP_SYMBOL(IC_RESULT(ic))->defs,ic->key);
3023 hTabDeleteItem (&iCodehTab, ic->key, ic, DELETE_ITEM, NULL);
3024 OP_DEFS(IC_RESULT (dic))=bitVectSetBit (OP_DEFS (IC_RESULT (dic)), dic->key);
3032 iTempNN := (some variable in farspace) V1
3037 if (ic->op == IPUSH)
3039 packForPush (ic, ebpp, blockno);
3043 /* pack registers for accumulator use, when the
3044 result of an arithmetic or bit wise operation
3045 has only one use, that use is immediately following
3046 the defintion and the using iCode has only one
3047 operand or has two operands but one is literal &
3048 the result of that operation is not on stack then
3049 we can leave the result of this operation in acc:b
3051 if ((IS_ARITHMETIC_OP (ic)
3052 || IS_CONDITIONAL(ic)
3053 || IS_BITWISE_OP (ic)
3054 || ic->op == LEFT_OP || ic->op == RIGHT_OP || ic->op == CALL
3055 || (ic->op == ADDRESS_OF && isOperandOnStack (IC_LEFT (ic)))
3057 IS_ITEMP (IC_RESULT (ic)) &&
3058 getSize (operandType (IC_RESULT (ic))) <= 2)
3060 packRegsForAccUse (ic);
3064 /*-----------------------------------------------------------------*/
3065 /* assignRegisters - assigns registers to each live range as need */
3066 /*-----------------------------------------------------------------*/
3068 mcs51_assignRegisters (eBBlock ** ebbs, int count)
3073 setToNull ((void *) &_G.funcrUsed);
3074 setToNull ((void *) &_G.regAssigned);
3075 setToNull ((void *) &_G.totRegAssigned);
3076 mcs51_ptrRegReq = _G.stackExtend = _G.dataExtend = 0;
3079 /* change assignments this will remove some
3080 live ranges reducing some register pressure */
3082 for (i = 0; i < count; i++)
3083 packRegisters (ebbs, i);
3085 /* liveranges probably changed by register packing
3086 so we compute them again */
3087 recomputeLiveRanges (ebbs, count);
3089 if (options.dump_pack)
3090 dumpEbbsToFileExt (DUMP_PACK, ebbs, count);
3092 /* first determine for each live range the number of
3093 registers & the type of registers required for each */
3096 /* and serially allocate registers */
3097 serialRegAssign (ebbs, count);
3100 //setToNull ((void *) &_G.regAssigned);
3101 //setToNull ((void *) &_G.totRegAssigned);
3104 /* if stack was extended then tell the user */
3107 /* werror(W_TOOMANY_SPILS,"stack", */
3108 /* _G.stackExtend,currFunc->name,""); */
3114 /* werror(W_TOOMANY_SPILS,"data space", */
3115 /* _G.dataExtend,currFunc->name,""); */
3119 /* after that create the register mask
3120 for each of the instruction */
3121 createRegMask (ebbs, count);
3123 /* redo that offsets for stacked automatic variables */
3125 redoStackOffsets ();
3128 /* make sure r0 & r1 are flagged as used if they might be used */
3130 if (currFunc && mcs51_ptrRegReq)
3132 currFunc->regsUsed = bitVectSetBit (currFunc->regsUsed, R0_IDX);
3133 currFunc->regsUsed = bitVectSetBit (currFunc->regsUsed, R1_IDX);
3136 if (options.dump_rassgn)
3138 dumpEbbsToFileExt (DUMP_RASSGN, ebbs, count);
3139 dumpLiveRanges (DUMP_LRANGE, liveRanges);
3142 /* do the overlaysegment stuff SDCCmem.c */
3143 doOverlays (ebbs, count);
3145 /* now get back the chain */
3146 ic = iCodeLabelOptimize (iCodeFromeBBlock (ebbs, count));
3150 /* free up any _G.stackSpil locations allocated */
3151 applyToSet (_G.stackSpil, deallocStackSpil);
3153 setToNull ((void *) &_G.stackSpil);
3154 setToNull ((void *) &_G.spiltSet);
3155 /* mark all registers as free */