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 with 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)
387 for (sym = setFirstItem (itmpStack); sym;
388 sym = setNextItem (itmpStack))
390 if (bitVectBitValue(sym->clashes,fsym->key)) return 0;
395 /*-----------------------------------------------------------------*/
396 /* isFree - will return 1 if the a free spil location is found */
397 /*-----------------------------------------------------------------*/
402 V_ARG (symbol **, sloc);
403 V_ARG (symbol *, fsym);
405 /* if already found */
409 /* if it is free && and the itmp assigned to
410 this does not have any overlapping live ranges
411 with the one currently being assigned and
412 the size can be accomodated */
414 noOverLap (sym->usl.itmpStack, fsym) &&
415 getSize (sym->type) >= getSize (fsym->type))
424 /*-----------------------------------------------------------------*/
425 /* spillLRWithPtrReg :- will spil those live ranges which use PTR */
426 /*-----------------------------------------------------------------*/
428 spillLRWithPtrReg (symbol * forSym)
434 if (!_G.regAssigned ||
435 bitVectIsZero (_G.regAssigned))
438 r0 = mcs51_regWithIdx (R0_IDX);
439 r1 = mcs51_regWithIdx (R1_IDX);
441 /* for all live ranges */
442 for (lrsym = hTabFirstItem (liveRanges, &k); lrsym;
443 lrsym = hTabNextItem (liveRanges, &k))
447 /* if no registers assigned to it or spilt */
448 /* if it does not overlap this then
449 no need to spill it */
451 if (lrsym->isspilt || !lrsym->nRegs ||
452 (lrsym->liveTo < forSym->liveFrom))
455 /* go thru the registers : if it is either
456 r0 or r1 then spill it */
457 for (j = 0; j < lrsym->nRegs; j++)
458 if (lrsym->regs[j] == r0 ||
459 lrsym->regs[j] == r1)
468 /*-----------------------------------------------------------------*/
469 /* createStackSpil - create a location on the stack to spil */
470 /*-----------------------------------------------------------------*/
472 createStackSpil (symbol * sym)
475 int useXstack, model;
479 /* first go try and find a free one that is already
480 existing on the stack */
481 if (applyToSet (_G.stackSpil, isFree, &sloc, sym))
483 /* found a free one : just update & return */
484 sym->usl.spillLoc = sloc;
487 addSetHead (&sloc->usl.itmpStack, sym);
491 /* could not then have to create one , this is the hard part
492 we need to allocate this on the stack : this is really a
493 hack!! but cannot think of anything better at this time */
495 if (SNPRINTF (slocBuffer, sizeof(slocBuffer),
496 "sloc%d", _G.slocNum++) >= sizeof (slocBuffer))
498 fprintf (stderr, "***Internal error: slocBuffer overflowed: %s:%d\n",
503 sloc = newiTemp (slocBuffer);
505 /* set the type to the spilling symbol */
506 sloc->type = copyLinkChain (sym->type);
507 sloc->etype = getSpec (sloc->type);
508 SPEC_SCLS (sloc->etype) = S_DATA;
509 SPEC_EXTR (sloc->etype) = 0;
510 SPEC_STAT (sloc->etype) = 0;
511 SPEC_VOLATILE(sloc->etype) = 0;
512 SPEC_ABSA(sloc->etype) = 0;
514 /* we don't allow it to be allocated`
515 onto the external stack since : so we
516 temporarily turn it off ; we also
517 turn off memory model to prevent
518 the spil from going to the external storage
521 useXstack = options.useXstack;
522 model = options.model;
523 /* noOverlay = options.noOverlay; */
524 /* options.noOverlay = 1; */
525 options.model = options.useXstack = 0;
529 options.useXstack = useXstack;
530 options.model = model;
531 /* options.noOverlay = noOverlay; */
532 sloc->isref = 1; /* to prevent compiler warning */
534 /* if it is on the stack then update the stack */
535 if (IN_STACK (sloc->etype))
537 currFunc->stack += getSize (sloc->type);
538 _G.stackExtend += getSize (sloc->type);
541 _G.dataExtend += getSize (sloc->type);
543 /* add it to the _G.stackSpil set */
544 addSetHead (&_G.stackSpil, sloc);
545 sym->usl.spillLoc = sloc;
548 /* add it to the set of itempStack set
549 of the spill location */
550 addSetHead (&sloc->usl.itmpStack, sym);
554 /*-----------------------------------------------------------------*/
555 /* isSpiltOnStack - returns true if the spil location is on stack */
556 /*-----------------------------------------------------------------*/
558 isSpiltOnStack (symbol * sym)
568 /* if (sym->_G.stackSpil) */
571 if (!sym->usl.spillLoc)
574 etype = getSpec (sym->usl.spillLoc->type);
575 if (IN_STACK (etype))
581 /*-----------------------------------------------------------------*/
582 /* spillThis - spils a specific operand */
583 /*-----------------------------------------------------------------*/
585 spillThis (symbol * sym)
588 /* if this is rematerializable or has a spillLocation
589 we are okay, else we need to create a spillLocation
591 if (!(sym->remat || sym->usl.spillLoc))
592 createStackSpil (sym);
594 /* mark it has spilt & put it in the spilt set */
595 sym->isspilt = sym->spillA = 1;
596 _G.spiltSet = bitVectSetBit (_G.spiltSet, sym->key);
598 bitVectUnSetBit (_G.regAssigned, sym->key);
599 bitVectUnSetBit (_G.totRegAssigned, sym->key);
601 for (i = 0; i < sym->nRegs; i++)
605 freeReg (sym->regs[i]);
609 /* if spilt on stack then free up r0 & r1
610 if they could have been assigned to some
612 if (!mcs51_ptrRegReq && isSpiltOnStack (sym))
615 spillLRWithPtrReg (sym);
618 if (sym->usl.spillLoc && !sym->remat)
619 sym->usl.spillLoc->allocreq++;
623 /*-----------------------------------------------------------------*/
624 /* selectSpil - select a iTemp to spil : rather a simple procedure */
625 /*-----------------------------------------------------------------*/
627 selectSpil (iCode * ic, eBBlock * ebp, symbol * forSym)
629 bitVect *lrcs = NULL;
633 /* get the spillable live ranges */
634 lrcs = computeSpillable (ic);
636 /* get all live ranges that are rematerizable */
637 if ((selectS = liveRangesWith (lrcs, rematable, ebp, ic)))
640 /* return the least used of these */
641 return leastUsedLR (selectS);
644 /* get live ranges with spillLocations in direct space */
645 if ((selectS = liveRangesWith (lrcs, directSpilLoc, ebp, ic)))
647 sym = leastUsedLR (selectS);
648 strncpyz (sym->rname,
649 sym->usl.spillLoc->rname[0] ?
650 sym->usl.spillLoc->rname : 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;
1124 /*------------------------------------------------------------------*/
1125 /* verifyRegsAssigned - make sure an iTemp is properly initialized; */
1126 /* it should either have registers or have beed spilled. Otherwise, */
1127 /* there was an uninitialized variable, so just spill this to get */
1128 /* the operand in a valid state. */
1129 /*------------------------------------------------------------------*/
1131 verifyRegsAssigned (operand *op, iCode * ic)
1136 if (!IS_ITEMP (op)) return;
1138 sym = OP_SYMBOL (op);
1139 if (sym->isspilt) return;
1140 if (!sym->nRegs) return;
1141 if (sym->regs[0]) return;
1143 werrorfl (ic->filename, ic->lineno, W_LOCAL_NOINIT,
1144 sym->prereqv ? sym->prereqv->name : sym->name);
1149 /*-----------------------------------------------------------------*/
1150 /* serialRegAssign - serially allocate registers to the variables */
1151 /*-----------------------------------------------------------------*/
1153 serialRegAssign (eBBlock ** ebbs, int count)
1157 /* for all blocks */
1158 for (i = 0; i < count; i++)
1163 if (ebbs[i]->noPath &&
1164 (ebbs[i]->entryLabel != entryLabel &&
1165 ebbs[i]->entryLabel != returnLabel))
1168 /* of all instructions do */
1169 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 liveranges that were 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;
1712 /* if plus or minus print the right hand side */
1713 if (ic->op == '+' || ic->op == '-')
1715 SNPRINTF (s, sizeof(buffer) - strlen(buffer),
1716 "0x%04x %c ", (int) operandLitValue (IC_RIGHT (ic)),
1719 ic = OP_SYMBOL (IC_LEFT (ic))->rematiCode;
1723 /* cast then continue */
1724 if (IS_CAST_ICODE(ic)) {
1725 ic = OP_SYMBOL (IC_RIGHT (ic))->rematiCode;
1728 /* we reached the end */
1729 SNPRINTF (s, sizeof(buffer) - strlen(buffer),
1730 "%s", OP_SYMBOL (IC_LEFT (ic))->rname);
1737 /*-----------------------------------------------------------------*/
1738 /* regTypeNum - computes the type & number of registers required */
1739 /*-----------------------------------------------------------------*/
1741 regTypeNum (eBBlock *ebbs)
1747 /* for each live range do */
1748 for (sym = hTabFirstItem (liveRanges, &k); sym;
1749 sym = hTabNextItem (liveRanges, &k))
1752 /* if used zero times then no registers needed */
1753 if ((sym->liveTo - sym->liveFrom) == 0)
1757 /* if the live range is a temporary */
1761 /* if the type is marked as a conditional */
1762 if (sym->regType == REG_CND)
1765 /* if used in return only then we don't
1767 if (sym->ruonly || sym->accuse)
1769 if (IS_AGGREGATE (sym->type) || sym->isptr)
1770 sym->type = aggrToPtr (sym->type, FALSE);
1774 /* if the symbol has only one definition &
1775 that definition is a get_pointer */
1776 if (bitVectnBitsOn (sym->defs) == 1 &&
1777 (ic = hTabItemWithKey (iCodehTab,
1778 bitVectFirstBit (sym->defs))) &&
1780 !IS_BITVAR (sym->etype) &&
1781 (aggrToPtrDclType (operandType (IC_LEFT (ic)), FALSE) == POINTER))
1784 if (ptrPseudoSymSafe (sym, ic))
1786 ptrPseudoSymConvert (sym, ic, rematStr (OP_SYMBOL (IC_LEFT (ic))));
1790 /* if in data space or idata space then try to
1791 allocate pointer register */
1795 /* if not then we require registers */
1796 sym->nRegs = ((IS_AGGREGATE (sym->type) || sym->isptr) ?
1797 getSize (sym->type = aggrToPtr (sym->type, FALSE)) :
1798 getSize (sym->type));
1802 fprintf (stderr, "allocated more than 4 or 0 registers for type ");
1803 printTypeChain (sym->type, stderr);
1804 fprintf (stderr, "\n");
1807 /* determine the type of register required */
1808 if (sym->nRegs == 1 &&
1809 IS_PTR (sym->type) &&
1811 sym->regType = REG_PTR;
1813 sym->regType = REG_GPR;
1817 /* for the first run we don't provide */
1818 /* registers for true symbols we will */
1819 /* see how things go */
1825 /*-----------------------------------------------------------------*/
1826 /* freeAllRegs - mark all registers as free */
1827 /*-----------------------------------------------------------------*/
1833 for (i = 0; i < mcs51_nRegs; i++)
1834 regs8051[i].isFree = 1;
1837 /*-----------------------------------------------------------------*/
1838 /* deallocStackSpil - this will set the stack pointer back */
1839 /*-----------------------------------------------------------------*/
1841 DEFSETFUNC (deallocStackSpil)
1849 /*-----------------------------------------------------------------*/
1850 /* farSpacePackable - returns the packable icode for far variables */
1851 /*-----------------------------------------------------------------*/
1853 farSpacePackable (iCode * ic)
1857 /* go thru till we find a definition for the
1858 symbol on the right */
1859 for (dic = ic->prev; dic; dic = dic->prev)
1861 /* if the definition is a call then no */
1862 if ((dic->op == CALL || dic->op == PCALL) &&
1863 IC_RESULT (dic)->key == IC_RIGHT (ic)->key)
1868 /* if shift by unknown amount then not */
1869 if ((dic->op == LEFT_OP || dic->op == RIGHT_OP) &&
1870 IC_RESULT (dic)->key == IC_RIGHT (ic)->key)
1873 /* if pointer get and size > 1 */
1874 if (POINTER_GET (dic) &&
1875 getSize (aggrToPtr (operandType (IC_LEFT (dic)), FALSE)) > 1)
1878 if (POINTER_SET (dic) &&
1879 getSize (aggrToPtr (operandType (IC_RESULT (dic)), FALSE)) > 1)
1884 if (IC_COND (dic) &&
1885 IS_TRUE_SYMOP (IC_COND (dic)) &&
1886 isOperandInFarSpace (IC_COND (dic)))
1889 else if (dic->op == JUMPTABLE)
1891 if (IC_JTCOND (dic) &&
1892 IS_TRUE_SYMOP (IC_JTCOND (dic)) &&
1893 isOperandInFarSpace (IC_JTCOND (dic)))
1898 /* if any tree is a true symbol in far space */
1899 if (IC_RESULT (dic) &&
1900 IS_TRUE_SYMOP (IC_RESULT (dic)) &&
1901 isOperandInFarSpace (IC_RESULT (dic)))
1904 if (IC_RIGHT (dic) &&
1905 IS_TRUE_SYMOP (IC_RIGHT (dic)) &&
1906 isOperandInFarSpace (IC_RIGHT (dic)) &&
1907 !isOperandEqual (IC_RIGHT (dic), IC_RESULT (ic)))
1910 if (IC_LEFT (dic) &&
1911 IS_TRUE_SYMOP (IC_LEFT (dic)) &&
1912 isOperandInFarSpace (IC_LEFT (dic)) &&
1913 !isOperandEqual (IC_LEFT (dic), IC_RESULT (ic)))
1917 if (isOperandEqual (IC_RIGHT (ic), IC_RESULT (dic)))
1919 if ((dic->op == LEFT_OP ||
1920 dic->op == RIGHT_OP ||
1922 IS_OP_LITERAL (IC_RIGHT (dic)))
1932 /*-----------------------------------------------------------------*/
1933 /* packRegsForAssign - register reduction for assignment */
1934 /*-----------------------------------------------------------------*/
1936 packRegsForAssign (iCode * ic, eBBlock * ebp)
1940 if (!IS_ITEMP (IC_RIGHT (ic)) ||
1941 OP_SYMBOL (IC_RIGHT (ic))->isind ||
1942 OP_LIVETO (IC_RIGHT (ic)) > ic->seq)
1947 /* if the true symbol is defined in far space or on stack
1948 then we should not since this will increase register pressure */
1949 if (isOperandInFarSpace(IC_RESULT(ic)) && !farSpacePackable(ic)) {
1953 /* find the definition of iTempNN scanning backwards if we find a
1954 a use of the true symbol in before we find the definition then
1956 for (dic = ic->prev; dic; dic = dic->prev)
1958 int crossedCall = 0;
1960 /* We can pack across a function call only if it's a local */
1961 /* variable or our parameter. Never pack global variables */
1962 /* or parameters to a function we call. */
1963 if ((dic->op == CALL || dic->op == PCALL))
1965 if (!OP_SYMBOL (IC_RESULT (ic))->ismyparm
1966 && !OP_SYMBOL (IC_RESULT (ic))->islocal)
1977 if (IS_SYMOP (IC_COND (dic)) &&
1978 (IC_COND (dic)->key == IC_RESULT (ic)->key ||
1979 IC_COND (dic)->key == IC_RIGHT (ic)->key))
1987 if (IS_TRUE_SYMOP (IC_RESULT (dic)) &&
1988 IS_OP_VOLATILE (IC_RESULT (dic)))
1994 if (IS_SYMOP (IC_RESULT (dic)) &&
1995 IC_RESULT (dic)->key == IC_RIGHT (ic)->key)
1997 if (POINTER_SET (dic))
2003 if (IS_SYMOP (IC_RIGHT (dic)) &&
2004 (IC_RIGHT (dic)->key == IC_RESULT (ic)->key ||
2005 IC_RIGHT (dic)->key == IC_RIGHT (ic)->key))
2011 if (IS_SYMOP (IC_LEFT (dic)) &&
2012 (IC_LEFT (dic)->key == IC_RESULT (ic)->key ||
2013 IC_LEFT (dic)->key == IC_RIGHT (ic)->key))
2019 if (IS_SYMOP (IC_RESULT (dic)) &&
2020 IC_RESULT (dic)->key == IC_RESULT (ic)->key)
2036 return 0; /* did not find */
2038 /* if assignment then check that right is not a bit */
2039 if (ASSIGNMENT (ic) && !POINTER_SET (ic))
2041 sym_link *etype = operandType (IC_RESULT (dic));
2042 if (IS_BITFIELD (etype))
2044 /* if result is a bit too then it's ok */
2045 etype = operandType (IC_RESULT (ic));
2046 if (!IS_BITFIELD (etype))
2053 /* if assignment then check that right is not a bit */
2054 if (ASSIGNMENT (dic) && !POINTER_SET (dic))
2056 sym_link *etype = operandType (IC_RIGHT (dic));
2057 if (IS_BITFIELD (etype))
2059 /* if result is a bit too then it's ok */
2060 etype = operandType (IC_RESULT (dic));
2061 if (!IS_BITFIELD (etype))
2066 /* if the result is on stack or iaccess then it must be
2067 the same atleast one of the operands */
2068 if (OP_SYMBOL (IC_RESULT (ic))->onStack ||
2069 OP_SYMBOL (IC_RESULT (ic))->iaccess)
2072 /* the operation has only one symbol
2073 operator then we can pack */
2074 if ((IC_LEFT (dic) && !IS_SYMOP (IC_LEFT (dic))) ||
2075 (IC_RIGHT (dic) && !IS_SYMOP (IC_RIGHT (dic))))
2078 if (!((IC_LEFT (dic) &&
2079 IC_RESULT (ic)->key == IC_LEFT (dic)->key) ||
2081 IC_RESULT (ic)->key == IC_RIGHT (dic)->key)))
2085 /* found the definition */
2086 /* replace the result with the result of */
2087 /* this assignment and remove this assignment */
2088 bitVectUnSetBit(OP_SYMBOL(IC_RESULT(dic))->defs,dic->key);
2089 ReplaceOpWithCheaperOp(&IC_RESULT (dic), IC_RESULT (ic));
2091 if (IS_ITEMP (IC_RESULT (dic)) && OP_SYMBOL (IC_RESULT (dic))->liveFrom > dic->seq)
2093 OP_SYMBOL (IC_RESULT (dic))->liveFrom = dic->seq;
2095 // TODO: and the otherway around?
2097 /* delete from liverange table also
2098 delete from all the points inbetween and the new
2100 for (sic = dic; sic != ic; sic = sic->next)
2102 bitVectUnSetBit (sic->rlive, IC_RESULT (ic)->key);
2103 if (IS_ITEMP (IC_RESULT (dic)))
2104 bitVectSetBit (sic->rlive, IC_RESULT (dic)->key);
2107 remiCodeFromeBBlock (ebp, ic);
2108 bitVectUnSetBit(OP_SYMBOL(IC_RESULT(ic))->defs,ic->key);
2109 hTabDeleteItem (&iCodehTab, ic->key, ic, DELETE_ITEM, NULL);
2110 OP_DEFS(IC_RESULT (dic))=bitVectSetBit (OP_DEFS (IC_RESULT (dic)), dic->key);
2114 /*------------------------------------------------------------------*/
2115 /* findAssignToSym : scanning backwards looks for first assig found */
2116 /*------------------------------------------------------------------*/
2118 findAssignToSym (operand * op, iCode * ic)
2122 /* This routine is used to find sequences like
2124 ...; (intervening ops don't use iTempAA or modify FOO)
2125 blah = blah + iTempAA;
2127 and eliminate the use of iTempAA, freeing up its register for
2131 for (dic = ic->prev; dic; dic = dic->prev)
2134 /* if definition by assignment */
2135 if (dic->op == '=' &&
2136 !POINTER_SET (dic) &&
2137 IC_RESULT (dic)->key == op->key
2138 /* && IS_TRUE_SYMOP(IC_RIGHT(dic)) */
2140 break; /* found where this temp was defined */
2142 /* if we find an usage then we cannot delete it */
2146 if (IC_COND (dic) && IC_COND (dic)->key == op->key)
2149 else if (dic->op == JUMPTABLE)
2151 if (IC_JTCOND (dic) && IC_JTCOND (dic)->key == op->key)
2156 if (IC_LEFT (dic) && IC_LEFT (dic)->key == op->key)
2159 if (IC_RIGHT (dic) && IC_RIGHT (dic)->key == op->key)
2162 if (POINTER_SET (dic) && IC_RESULT (dic)->key == op->key)
2168 return NULL; /* didn't find any assignment to op */
2170 /* we are interested only if defined in far space */
2171 /* or in stack space in case of + & - */
2173 /* if assigned to a non-symbol then don't repack regs */
2174 if (!IS_SYMOP (IC_RIGHT (dic)))
2177 /* if the symbol is volatile then we should not */
2178 if (isOperandVolatile (IC_RIGHT (dic), TRUE))
2180 /* XXX TODO --- should we be passing FALSE to isOperandVolatile()?
2181 What does it mean for an iTemp to be volatile, anyway? Passing
2182 TRUE is more cautious but may prevent possible optimizations */
2184 /* if the symbol is in far space then we should not */
2185 if (isOperandInFarSpace (IC_RIGHT (dic)))
2188 /* for + & - operations make sure that
2189 if it is on the stack it is the same
2190 as one of the three operands */
2191 if ((ic->op == '+' || ic->op == '-') &&
2192 OP_SYMBOL (IC_RIGHT (dic))->onStack)
2195 if (IC_RESULT (ic)->key != IC_RIGHT (dic)->key &&
2196 IC_LEFT (ic)->key != IC_RIGHT (dic)->key &&
2197 IC_RIGHT (ic)->key != IC_RIGHT (dic)->key)
2201 /* now make sure that the right side of dic
2202 is not defined between ic & dic */
2205 iCode *sic = dic->next;
2207 for (; sic != ic; sic = sic->next)
2208 if (IC_RESULT (sic) &&
2209 IC_RESULT (sic)->key == IC_RIGHT (dic)->key)
2216 /*-----------------------------------------------------------------*/
2217 /* reassignAliasedSym - used by packRegsForSupport to replace */
2218 /* redundant iTemp with equivalent symbol */
2219 /*-----------------------------------------------------------------*/
2221 reassignAliasedSym (eBBlock *ebp, iCode *assignment, iCode *use, operand *op)
2224 unsigned oldSymKey, newSymKey;
2226 oldSymKey = op->key;
2227 newSymKey = IC_RIGHT(assignment)->key;
2229 /* only track live ranges of compiler-generated temporaries */
2230 if (!IS_ITEMP(IC_RIGHT(assignment)))
2233 /* update the live-value bitmaps */
2234 for (ic = assignment; ic != use; ic = ic->next) {
2235 bitVectUnSetBit (ic->rlive, oldSymKey);
2237 ic->rlive = bitVectSetBit (ic->rlive, newSymKey);
2240 /* update the sym of the used operand */
2241 OP_SYMBOL(op) = OP_SYMBOL(IC_RIGHT(assignment));
2242 op->key = OP_SYMBOL(op)->key;
2243 OP_SYMBOL(op)->accuse = 0;
2245 /* update the sym's liverange */
2246 if ( OP_LIVETO(op) < ic->seq )
2247 setToRange(op, ic->seq, FALSE);
2249 /* remove the assignment iCode now that its result is unused */
2250 remiCodeFromeBBlock (ebp, assignment);
2251 bitVectUnSetBit(OP_SYMBOL(IC_RESULT(assignment))->defs, assignment->key);
2252 hTabDeleteItem (&iCodehTab, assignment->key, assignment, DELETE_ITEM, NULL);
2256 /*-----------------------------------------------------------------*/
2257 /* packRegsForSupport :- reduce some registers for support calls */
2258 /*-----------------------------------------------------------------*/
2260 packRegsForSupport (iCode * ic, eBBlock * ebp)
2264 /* for the left & right operand :- look to see if the
2265 left was assigned a true symbol in far space in that
2266 case replace them */
2268 if (IS_ITEMP (IC_LEFT (ic)) &&
2269 OP_SYMBOL (IC_LEFT (ic))->liveTo <= ic->seq)
2271 dic = findAssignToSym (IC_LEFT (ic), ic);
2275 /* found it we need to remove it from the block */
2276 reassignAliasedSym (ebp, dic, ic, IC_LEFT(ic));
2281 /* do the same for the right operand */
2282 if (IS_ITEMP (IC_RIGHT (ic)) &&
2283 OP_SYMBOL (IC_RIGHT (ic))->liveTo <= ic->seq)
2285 iCode *dic = findAssignToSym (IC_RIGHT (ic), ic);
2289 /* if this is a subtraction & the result
2290 is a true symbol in far space then don't pack */
2291 if (ic->op == '-' && IS_TRUE_SYMOP (IC_RESULT (dic)))
2293 sym_link *etype = getSpec (operandType (IC_RESULT (dic)));
2294 if (IN_FARSPACE (SPEC_OCLS (etype)))
2297 /* found it we need to remove it from the
2299 reassignAliasedSym (ebp, dic, ic, IC_RIGHT(ic));
2308 #define IS_OP_RUONLY(x) (x && IS_SYMOP(x) && OP_SYMBOL(x)->ruonly)
2311 /*-----------------------------------------------------------------*/
2312 /* packRegsForOneuse : - will reduce some registers for single Use */
2313 /*-----------------------------------------------------------------*/
2315 packRegsForOneuse (iCode * ic, operand * op, eBBlock * ebp)
2319 /* if returning a literal then do nothing */
2323 /* if rematerializable or already return use then do nothing */
2324 if (OP_SYMBOL(op)->remat || OP_SYMBOL(op)->ruonly)
2327 /* only upto 2 bytes since we cannot predict
2328 the usage of b, & acc */
2329 if (getSize (operandType (op)) > (fReturnSizeMCS51 - 2))
2332 if (ic->op != RETURN &&
2334 !POINTER_SET (ic) &&
2338 if (ic->op == SEND && ic->argreg != 1) return NULL;
2340 /* this routine will mark the a symbol as used in one
2341 instruction use only && if the defintion is local
2342 (ie. within the basic block) && has only one definition &&
2343 that definiion is either a return value from a
2344 function or does not contain any variables in
2346 if (bitVectnBitsOn (OP_USES (op)) > 1)
2349 /* if it has only one defintion */
2350 if (bitVectnBitsOn (OP_DEFS (op)) > 1)
2351 return NULL; /* has more than one definition */
2353 /* get that definition */
2355 hTabItemWithKey (iCodehTab,
2356 bitVectFirstBit (OP_DEFS (op)))))
2359 /* if that only usage is a cast */
2360 if (dic->op == CAST) {
2361 /* to a bigger type */
2362 if (getSize(OP_SYM_TYPE(IC_RESULT(dic))) >
2363 getSize(OP_SYM_TYPE(IC_RIGHT(dic)))) {
2364 /* than we can not, since we cannot predict the usage of b & acc */
2369 /* found the definition now check if it is local */
2370 if (dic->seq < ebp->fSeq ||
2371 dic->seq > ebp->lSeq)
2372 return NULL; /* non-local */
2374 /* now check if it is the return from
2376 if (dic->op == CALL || dic->op == PCALL)
2378 if (ic->op != SEND && ic->op != RETURN &&
2379 !POINTER_SET(ic) && !POINTER_GET(ic))
2381 OP_SYMBOL (op)->ruonly = 1;
2387 /* otherwise check that the definition does
2388 not contain any symbols in far space */
2389 if (isOperandInFarSpace (IC_LEFT (dic)) ||
2390 isOperandInFarSpace (IC_RIGHT (dic)) ||
2391 IS_OP_RUONLY (IC_LEFT (ic)) ||
2392 IS_OP_RUONLY (IC_RIGHT (ic)))
2397 /* if pointer set then make sure the pointer
2399 if (POINTER_SET (dic) &&
2400 !IS_DATA_PTR (aggrToPtr (operandType (IC_RESULT (dic)), FALSE)))
2403 if (POINTER_GET (dic) &&
2404 !IS_DATA_PTR (aggrToPtr (operandType (IC_LEFT (dic)), FALSE)))
2408 /* Make sure no overlapping liverange is already assigned to DPTR */
2409 if (OP_SYMBOL(op)->clashes)
2414 for (i = 0 ; i < OP_SYMBOL(op)->clashes->size ; i++ )
2416 if (bitVectBitValue(OP_SYMBOL(op)->clashes,i))
2418 sym = hTabItemWithKey(liveRanges,i);
2427 /* also make sure the intervenening instructions
2428 don't have any thing in far space */
2429 for (dic = dic->next; dic && dic != ic && sic != ic; dic = dic->next)
2432 /* if there is an intervening function call then no */
2433 if (dic->op == CALL || dic->op == PCALL)
2435 /* if pointer set then make sure the pointer
2437 if (POINTER_SET (dic) &&
2438 !IS_DATA_PTR (aggrToPtr (operandType (IC_RESULT (dic)), FALSE)))
2441 if (POINTER_GET (dic) &&
2442 !IS_DATA_PTR (aggrToPtr (operandType (IC_LEFT (dic)), FALSE)))
2445 /* if address of & the result is remat the okay */
2446 if (dic->op == ADDRESS_OF &&
2447 OP_SYMBOL (IC_RESULT (dic))->remat)
2450 /* if operand has size of three or more & this
2451 operation is a '*','/' or '%' then 'b' may
2453 if ((dic->op == '%' || dic->op == '/' || dic->op == '*') &&
2454 getSize (operandType (op)) >= 3)
2457 /* if left or right or result is in far space */
2458 if (isOperandInFarSpace (IC_LEFT (dic)) ||
2459 isOperandInFarSpace (IC_RIGHT (dic)) ||
2460 isOperandInFarSpace (IC_RESULT (dic)) ||
2461 IS_OP_RUONLY (IC_LEFT (dic)) ||
2462 IS_OP_RUONLY (IC_RIGHT (dic)) ||
2463 IS_OP_RUONLY (IC_RESULT (dic)))
2467 /* if left or right or result is on stack */
2468 if (isOperandOnStack(IC_LEFT(dic)) ||
2469 isOperandOnStack(IC_RIGHT(dic)) ||
2470 isOperandOnStack(IC_RESULT(dic))) {
2475 OP_SYMBOL (op)->ruonly = 1;
2479 /*-----------------------------------------------------------------*/
2480 /* isBitwiseOptimizable - requirements of JEAN LOUIS VERN */
2481 /*-----------------------------------------------------------------*/
2483 isBitwiseOptimizable (iCode * ic)
2485 sym_link *ltype = getSpec (operandType (IC_LEFT (ic)));
2486 sym_link *rtype = getSpec (operandType (IC_RIGHT (ic)));
2488 /* bitwise operations are considered optimizable
2489 under the following conditions (Jean-Louis VERN)
2501 if (IS_LITERAL(rtype) ||
2502 (IS_BITVAR (ltype) && IN_BITSPACE (SPEC_OCLS (ltype))))
2508 /*-----------------------------------------------------------------*/
2509 /* isCommutativeOp - tests whether this op cares what order its */
2510 /* operands are in */
2511 /*-----------------------------------------------------------------*/
2512 bool isCommutativeOp(unsigned int op)
2514 if (op == '+' || op == '*' || op == EQ_OP ||
2515 op == '^' || op == '|' || op == BITWISEAND)
2521 /*-----------------------------------------------------------------*/
2522 /* operandUsesAcc - determines whether the code generated for this */
2523 /* operand will have to use the accumulator */
2524 /*-----------------------------------------------------------------*/
2525 bool operandUsesAcc(operand *op)
2531 symbol *sym = OP_SYMBOL(op);
2535 return TRUE; /* duh! */
2537 if (IN_STACK(sym->etype) || sym->onStack ||
2538 (SPIL_LOC(op) && SPIL_LOC(op)->onStack))
2539 return TRUE; /* acc is used to calc stack offset */
2544 sym = SPIL_LOC(op); /* if spilled, look at spill location */
2546 return FALSE; /* more checks? */
2550 symspace = SPEC_OCLS(sym->etype);
2552 if (sym->iaccess && symspace->paged)
2553 return TRUE; /* must fetch paged indirect sym via accumulator */
2555 if (IN_BITSPACE(symspace))
2556 return TRUE; /* fetching bit vars uses the accumulator */
2558 if (IN_FARSPACE(symspace) || IN_CODESPACE(symspace))
2559 return TRUE; /* fetched via accumulator and dptr */
2565 /*-----------------------------------------------------------------*/
2566 /* packRegsForAccUse - pack registers for acc use */
2567 /*-----------------------------------------------------------------*/
2569 packRegsForAccUse (iCode * ic)
2573 /* if this is an aggregate, e.g. a one byte char array */
2574 if (IS_AGGREGATE(operandType(IC_RESULT(ic)))) {
2578 /* if we are calling a reentrant function that has stack parameters */
2579 if (ic->op == CALL &&
2580 IFFUNC_ISREENT(operandType(IC_LEFT(ic))) &&
2581 FUNC_HASSTACKPARM(operandType(IC_LEFT(ic))))
2584 if (ic->op == PCALL &&
2585 IFFUNC_ISREENT(operandType(IC_LEFT(ic))->next) &&
2586 FUNC_HASSTACKPARM(operandType(IC_LEFT(ic))->next))
2589 /* if + or - then it has to be one byte result */
2590 if ((ic->op == '+' || ic->op == '-')
2591 && getSize (operandType (IC_RESULT (ic))) > 1)
2594 /* if shift operation make sure right side is not a literal */
2595 if (ic->op == RIGHT_OP &&
2596 (isOperandLiteral (IC_RIGHT (ic)) ||
2597 getSize (operandType (IC_RESULT (ic))) > 1))
2600 if (ic->op == LEFT_OP &&
2601 (isOperandLiteral (IC_RIGHT (ic)) ||
2602 getSize (operandType (IC_RESULT (ic))) > 1))
2605 if (IS_BITWISE_OP (ic) &&
2606 getSize (operandType (IC_RESULT (ic))) > 1)
2610 /* has only one definition */
2611 if (bitVectnBitsOn (OP_DEFS (IC_RESULT (ic))) > 1)
2614 /* has only one use */
2615 if (bitVectnBitsOn (OP_USES (IC_RESULT (ic))) > 1)
2618 /* and the usage immediately follows this iCode */
2619 if (!(uic = hTabItemWithKey (iCodehTab,
2620 bitVectFirstBit (OP_USES (IC_RESULT (ic))))))
2623 if (ic->next != uic)
2626 /* if it is a conditional branch then we definitely can */
2630 if (uic->op == JUMPTABLE)
2633 if (POINTER_SET (uic) &&
2634 getSize (aggrToPtr (operandType (IC_RESULT (uic)), FALSE)) > 1)
2637 /* if the usage is not is an assignment
2638 or an arithmetic / bitwise / shift operation then not */
2639 if (uic->op != '=' &&
2640 !IS_ARITHMETIC_OP (uic) &&
2641 !IS_BITWISE_OP (uic) &&
2642 uic->op != LEFT_OP &&
2643 uic->op != RIGHT_OP)
2646 /* if used in ^ operation then make sure right is not a
2647 literal (WIML: Why is this?) */
2648 if (uic->op == '^' && isOperandLiteral (IC_RIGHT (uic)))
2651 /* if shift operation make sure right side is not a literal */
2652 /* WIML: Why is this? */
2653 if (uic->op == RIGHT_OP &&
2654 (isOperandLiteral (IC_RIGHT (uic)) ||
2655 getSize (operandType (IC_RESULT (uic))) > 1))
2657 if (uic->op == LEFT_OP &&
2658 (isOperandLiteral (IC_RIGHT (uic)) ||
2659 getSize (operandType (IC_RESULT (uic))) > 1))
2662 /* make sure that the result of this icode is not on the
2663 stack, since acc is used to compute stack offset */
2665 if (IS_TRUE_SYMOP (IC_RESULT (uic)) &&
2666 OP_SYMBOL (IC_RESULT (uic))->onStack)
2669 if (isOperandOnStack(IC_RESULT(uic)))
2673 /* if the usage has only one operand then we can */
2674 if (IC_LEFT (uic) == NULL ||
2675 IC_RIGHT (uic) == NULL)
2678 /* if the other operand uses the accumulator then we cannot */
2679 if ( (IC_LEFT(uic)->key == IC_RESULT(ic)->key &&
2680 operandUsesAcc(IC_RIGHT(uic))) ||
2681 (IC_RIGHT(uic)->key == IC_RESULT(ic)->key &&
2682 operandUsesAcc(IC_LEFT(uic))) )
2685 /* make sure this is on the left side if not commutative */
2686 /* except for '-', which has been written to be able to
2687 handle reversed operands */
2688 if (!(isCommutativeOp(ic->op) || ic->op == '-') &&
2689 IC_LEFT (uic)->key != IC_RESULT (ic)->key)
2693 // this is too dangerous and need further restrictions
2696 /* if one of them is a literal then we can */
2697 if ((IC_LEFT (uic) && IS_OP_LITERAL (IC_LEFT (uic))) ||
2698 (IC_RIGHT (uic) && IS_OP_LITERAL (IC_RIGHT (uic))))
2700 OP_SYMBOL (IC_RESULT (ic))->accuse = 1;
2706 OP_SYMBOL (IC_RESULT (ic))->accuse = 1;
2710 /*-----------------------------------------------------------------*/
2711 /* packForPush - hueristics to reduce iCode for pushing */
2712 /*-----------------------------------------------------------------*/
2714 packForPush (iCode * ic, eBBlock ** ebpp, int blockno)
2718 struct eBBlock * ebp=ebpp[blockno];
2720 if (ic->op != IPUSH || !IS_ITEMP (IC_LEFT (ic)))
2723 /* must have only definition & one usage */
2724 if (bitVectnBitsOn (OP_DEFS (IC_LEFT (ic))) != 1 ||
2725 bitVectnBitsOn (OP_USES (IC_LEFT (ic))) != 1)
2728 /* find the definition */
2729 if (!(dic = hTabItemWithKey (iCodehTab,
2730 bitVectFirstBit (OP_DEFS (IC_LEFT (ic))))))
2733 if (dic->op != '=' || POINTER_SET (dic))
2736 if (dic->seq < ebp->fSeq) { // Evelyn did this
2738 for (i=0; i<blockno; i++) {
2739 if (dic->seq >= ebpp[i]->fSeq && dic->seq <= ebpp[i]->lSeq) {
2744 wassert (i!=blockno); // no way to recover from here
2747 if (IS_SYMOP(IC_RIGHT(dic))) {
2748 /* make sure the right side does not have any definitions
2750 dbv = OP_DEFS(IC_RIGHT(dic));
2751 for (lic = ic; lic && lic != dic ; lic = lic->prev) {
2752 if (bitVectBitValue(dbv,lic->key))
2755 /* make sure they have the same type */
2756 if (IS_SPEC(operandType(IC_LEFT(ic))))
2758 sym_link *itype=operandType(IC_LEFT(ic));
2759 sym_link *ditype=operandType(IC_RIGHT(dic));
2761 if (SPEC_USIGN(itype)!=SPEC_USIGN(ditype) ||
2762 SPEC_LONG(itype)!=SPEC_LONG(ditype))
2765 /* extend the live range of replaced operand if needed */
2766 if (OP_SYMBOL(IC_RIGHT(dic))->liveTo < ic->seq) {
2767 OP_SYMBOL(IC_RIGHT(dic))->liveTo = ic->seq;
2769 bitVectUnSetBit(OP_SYMBOL(IC_RESULT(dic))->defs,dic->key);
2772 /* we now we know that it has one & only one def & use
2773 and the that the definition is an assignment */
2774 ReplaceOpWithCheaperOp(&IC_LEFT (ic), IC_RIGHT (dic));
2775 remiCodeFromeBBlock (ebp, dic);
2776 hTabDeleteItem (&iCodehTab, dic->key, dic, DELETE_ITEM, NULL);
2779 /*-----------------------------------------------------------------*/
2780 /* packRegisters - does some transformations to reduce register */
2782 /*-----------------------------------------------------------------*/
2784 packRegisters (eBBlock ** ebpp, int blockno)
2788 eBBlock *ebp=ebpp[blockno];
2794 /* look for assignments of the form */
2795 /* iTempNN = TRueSym (someoperation) SomeOperand */
2797 /* TrueSym := iTempNN:1 */
2798 for (ic = ebp->sch; ic; ic = ic->next)
2800 /* find assignment of the form TrueSym := iTempNN:1 */
2801 if (ic->op == '=' && !POINTER_SET (ic))
2802 change += packRegsForAssign (ic, ebp);
2809 for (ic = ebp->sch; ic; ic = ic->next)
2811 /* Fix for bug #979599: */
2814 /* Look for two subsequent iCodes with */
2816 /* _c = iTemp & op; */
2817 /* and replace them by */
2819 if ((ic->op == BITWISEAND || ic->op == '|' || ic->op == '^') &&
2820 /* avoid trouble with unary '&' */
2823 ic->prev->op == '=' &&
2824 IS_ITEMP (IC_LEFT (ic)) &&
2825 IC_LEFT (ic) == IC_RESULT (ic->prev) &&
2826 isOperandEqual (IC_RESULT(ic), IC_RIGHT(ic->prev)))
2828 int key = ic->prev->key;
2830 bitVectUnSetBit (OP_SYMBOL (IC_RESULT (ic->prev))->defs, key);
2831 ReplaceOpWithCheaperOp (&IC_LEFT (ic), IC_RESULT (ic));
2832 if (/*IS_ITEMP (IC_RESULT (ic->prev)) && */
2833 OP_SYMBOL (IC_RESULT (ic->prev))->liveFrom > ic->seq)
2835 OP_SYMBOL (IC_RESULT (ic->prev))->liveFrom = ic->seq;
2837 // TODO: and the other way round?
2839 /* delete from liverange table also
2840 delete from all the points in between and the new one */
2841 bitVectUnSetBit (ic->prev->rlive, IC_RESULT (ic->prev)->key);
2842 bitVectSetBit (ic->prev->rlive, IC_RESULT (ic)->key);
2843 bitVectUnSetBit (ic->rlive, IC_RESULT (ic->prev)->key);
2844 bitVectSetBit (ic->rlive, IC_RESULT (ic)->key);
2846 remiCodeFromeBBlock (ebp, ic->prev);
2847 // bitVectUnSetBit (OP_SYMBOL (IC_RESULT (ic))->defs, ic->key);
2848 hTabDeleteItem (&iCodehTab, key, ic->prev, DELETE_ITEM, NULL);
2849 // OP_DEFS (IC_RESULT (ic->prev)) = bitVectSetBit (OP_DEFS (IC_RESULT (ic->prev)), ic->prev->key);
2852 /* if this is an itemp & result of an address of a true sym
2853 then mark this as rematerialisable */
2854 if (ic->op == ADDRESS_OF &&
2855 IS_ITEMP (IC_RESULT (ic)) &&
2856 IS_TRUE_SYMOP (IC_LEFT (ic)) &&
2857 bitVectnBitsOn (OP_DEFS (IC_RESULT (ic))) == 1 &&
2858 !OP_SYMBOL (IC_LEFT (ic))->onStack)
2860 OP_SYMBOL (IC_RESULT (ic))->remat = 1;
2861 OP_SYMBOL (IC_RESULT (ic))->rematiCode = ic;
2862 OP_SYMBOL (IC_RESULT (ic))->usl.spillLoc = NULL;
2865 /* if straight assignment then carry remat flag if
2866 this is the only definition */
2867 if (ic->op == '=' &&
2868 !POINTER_SET (ic) &&
2869 IS_SYMOP (IC_RIGHT (ic)) &&
2870 OP_SYMBOL (IC_RIGHT (ic))->remat &&
2871 !IS_CAST_ICODE(OP_SYMBOL (IC_RIGHT (ic))->rematiCode) &&
2872 bitVectnBitsOn (OP_SYMBOL (IC_RESULT (ic))->defs) <= 1)
2874 OP_SYMBOL (IC_RESULT (ic))->remat =
2875 OP_SYMBOL (IC_RIGHT (ic))->remat;
2876 OP_SYMBOL (IC_RESULT (ic))->rematiCode =
2877 OP_SYMBOL (IC_RIGHT (ic))->rematiCode;
2880 /* if cast to a generic pointer & the pointer being
2881 cast is remat, then we can remat this cast as well */
2882 if (ic->op == CAST &&
2883 IS_SYMOP(IC_RIGHT(ic)) &&
2884 OP_SYMBOL(IC_RIGHT(ic))->remat &&
2885 bitVectnBitsOn (OP_DEFS (IC_RESULT (ic))) == 1)
2887 sym_link *to_type = operandType(IC_LEFT(ic));
2888 sym_link *from_type = operandType(IC_RIGHT(ic));
2889 if (IS_GENPTR(to_type) && IS_PTR(from_type))
2891 OP_SYMBOL (IC_RESULT (ic))->remat = 1;
2892 OP_SYMBOL (IC_RESULT (ic))->rematiCode = ic;
2893 OP_SYMBOL (IC_RESULT (ic))->usl.spillLoc = NULL;
2897 /* if this is a +/- operation with a rematerizable
2898 then mark this as rematerializable as well */
2899 if ((ic->op == '+' || ic->op == '-') &&
2900 (IS_SYMOP (IC_LEFT (ic)) &&
2901 IS_ITEMP (IC_RESULT (ic)) &&
2902 IS_OP_LITERAL (IC_RIGHT (ic))) &&
2903 OP_SYMBOL (IC_LEFT (ic))->remat &&
2904 (!IS_SYMOP (IC_RIGHT (ic)) || !IS_CAST_ICODE(OP_SYMBOL (IC_RIGHT (ic))->rematiCode)) &&
2905 bitVectnBitsOn (OP_DEFS (IC_RESULT (ic))) == 1)
2907 OP_SYMBOL (IC_RESULT (ic))->remat = 1;
2908 OP_SYMBOL (IC_RESULT (ic))->rematiCode = ic;
2909 OP_SYMBOL (IC_RESULT (ic))->usl.spillLoc = NULL;
2912 /* mark the pointer usages */
2913 if (POINTER_SET (ic))
2914 OP_SYMBOL (IC_RESULT (ic))->uptr = 1;
2916 if (POINTER_GET (ic) &&
2917 IS_SYMOP(IC_LEFT (ic)))
2918 OP_SYMBOL (IC_LEFT (ic))->uptr = 1;
2922 /* if we are using a symbol on the stack
2923 then we should say mcs51_ptrRegReq */
2924 if (options.useXstack && ic->parmPush
2925 && (ic->op == IPUSH || ic->op == IPOP))
2927 if (ic->op == IFX && IS_SYMOP (IC_COND (ic)))
2928 mcs51_ptrRegReq += ((OP_SYMBOL (IC_COND (ic))->onStack ||
2929 OP_SYMBOL (IC_COND (ic))->iaccess ||
2930 SPEC_OCLS(OP_SYMBOL (IC_COND (ic))->etype) == idata) ? 1 : 0);
2931 else if (ic->op == JUMPTABLE && IS_SYMOP (IC_JTCOND (ic)))
2932 mcs51_ptrRegReq += ((OP_SYMBOL (IC_JTCOND (ic))->onStack ||
2933 OP_SYMBOL (IC_JTCOND (ic))->iaccess ||
2934 SPEC_OCLS(OP_SYMBOL (IC_JTCOND (ic))->etype) == idata) ? 1 : 0);
2937 if (IS_SYMOP (IC_LEFT (ic)))
2938 mcs51_ptrRegReq += ((OP_SYMBOL (IC_LEFT (ic))->onStack ||
2939 OP_SYMBOL (IC_LEFT (ic))->iaccess ||
2940 SPEC_OCLS(OP_SYMBOL (IC_LEFT (ic))->etype) == idata) ? 1 : 0);
2941 if (IS_SYMOP (IC_RIGHT (ic)))
2942 mcs51_ptrRegReq += ((OP_SYMBOL (IC_RIGHT (ic))->onStack ||
2943 OP_SYMBOL (IC_RIGHT (ic))->iaccess ||
2944 SPEC_OCLS(OP_SYMBOL (IC_RIGHT (ic))->etype) == idata) ? 1 : 0);
2945 if (IS_SYMOP (IC_RESULT (ic)))
2946 mcs51_ptrRegReq += ((OP_SYMBOL (IC_RESULT (ic))->onStack ||
2947 OP_SYMBOL (IC_RESULT (ic))->iaccess ||
2948 SPEC_OCLS(OP_SYMBOL (IC_RESULT (ic))->etype) == idata) ? 1 : 0);
2949 if (POINTER_GET (ic) && IS_SYMOP (IC_LEFT (ic))
2950 && getSize (OP_SYMBOL (IC_LEFT (ic))->type) <= (unsigned int) PTRSIZE)
2952 if (POINTER_SET (ic) && IS_SYMOP (IC_RESULT (ic))
2953 && getSize (OP_SYMBOL (IC_RESULT (ic))->type) <= (unsigned int) PTRSIZE)
2958 /* if the condition of an if instruction
2959 is defined in the previous instruction and
2960 this is the only usage then
2961 mark the itemp as a conditional */
2962 if ((IS_CONDITIONAL (ic) ||
2963 (IS_BITWISE_OP(ic) && isBitwiseOptimizable (ic)) ||
2964 (POINTER_GET (ic) && getSize (operandType (IC_RESULT (ic))) <=1)) &&
2965 ic->next && ic->next->op == IFX &&
2966 bitVectnBitsOn (OP_USES(IC_RESULT(ic)))==1 &&
2967 isOperandEqual (IC_RESULT (ic), IC_COND (ic->next)) &&
2968 OP_SYMBOL (IC_RESULT (ic))->liveTo <= ic->next->seq)
2970 OP_SYMBOL (IC_RESULT (ic))->regType = REG_CND;
2974 /* if the condition of an if instruction
2975 is defined in the previous GET_POINTER instruction and
2976 this is the only usage then
2977 mark the itemp as accumulator use */
2978 if ((POINTER_GET (ic) && getSize (operandType (IC_RESULT (ic))) <=1) &&
2979 ic->next && ic->next->op == IFX &&
2980 bitVectnBitsOn (OP_USES(IC_RESULT(ic)))==1 &&
2981 isOperandEqual (IC_RESULT (ic), IC_COND (ic->next)) &&
2982 OP_SYMBOL (IC_RESULT (ic))->liveTo <= ic->next->seq)
2984 OP_SYMBOL (IC_RESULT (ic))->accuse = 1;
2988 /* reduce for support function calls */
2989 if (ic->supportRtn || ic->op == '+' || ic->op == '-')
2990 packRegsForSupport (ic, ebp);
2992 /* some cases the redundant moves can
2993 can be eliminated for return statements */
2994 if ((ic->op == RETURN || (ic->op == SEND && ic->argreg == 1)) &&
2995 !isOperandInFarSpace (IC_LEFT (ic)) &&
2996 options.model == MODEL_SMALL) {
2997 packRegsForOneuse (ic, IC_LEFT (ic), ebp);
3000 /* if pointer set & left has a size more than
3001 one and right is not in far space */
3002 if (POINTER_SET (ic) &&
3003 !isOperandInFarSpace (IC_RIGHT (ic)) &&
3004 !OP_SYMBOL (IC_RESULT (ic))->remat &&
3005 !IS_OP_RUONLY (IC_RIGHT (ic)) &&
3006 getSize (aggrToPtr (operandType (IC_RESULT (ic)), FALSE)) > 1)
3007 packRegsForOneuse (ic, IC_RESULT (ic), ebp);
3009 /* if pointer get */
3010 if (POINTER_GET (ic) &&
3011 IS_SYMOP (IC_LEFT (ic)) &&
3012 !isOperandInFarSpace (IC_RESULT (ic)) &&
3013 !OP_SYMBOL (IC_LEFT (ic))->remat &&
3014 !IS_OP_RUONLY (IC_RESULT (ic)) &&
3015 getSize (aggrToPtr (operandType (IC_LEFT (ic)), FALSE)) > 1)
3016 packRegsForOneuse (ic, IC_LEFT (ic), ebp);
3019 /* if this is cast for intergral promotion then
3020 check if only use of the definition of the
3021 operand being casted/ if yes then replace
3022 the result of that arithmetic operation with
3023 this result and get rid of the cast */
3026 sym_link *fromType = operandType (IC_RIGHT (ic));
3027 sym_link *toType = operandType (IC_LEFT (ic));
3029 if (IS_INTEGRAL (fromType) && IS_INTEGRAL (toType) &&
3030 getSize (fromType) != getSize (toType) &&
3031 SPEC_USIGN (fromType) == SPEC_USIGN (toType))
3034 iCode *dic = packRegsForOneuse (ic, IC_RIGHT (ic), ebp);
3037 if (IS_ARITHMETIC_OP (dic))
3039 bitVectUnSetBit(OP_SYMBOL(IC_RESULT(dic))->defs,dic->key);
3040 ReplaceOpWithCheaperOp(&IC_RESULT (dic), IC_RESULT (ic));
3041 remiCodeFromeBBlock (ebp, ic);
3042 bitVectUnSetBit(OP_SYMBOL(IC_RESULT(ic))->defs,ic->key);
3043 hTabDeleteItem (&iCodehTab, ic->key, ic, DELETE_ITEM, NULL);
3044 OP_DEFS(IC_RESULT (dic))=bitVectSetBit (OP_DEFS (IC_RESULT (dic)), dic->key);
3048 OP_SYMBOL (IC_RIGHT (ic))->ruonly = 0;
3054 /* if the type from and type to are the same
3055 then if this is the only use then packit */
3056 if (compareType (operandType (IC_RIGHT (ic)),
3057 operandType (IC_LEFT (ic))) == 1)
3059 iCode *dic = packRegsForOneuse (ic, IC_RIGHT (ic), ebp);
3062 bitVectUnSetBit(OP_SYMBOL(IC_RESULT(dic))->defs,dic->key);
3063 ReplaceOpWithCheaperOp(&IC_RESULT (dic), IC_RESULT (ic));
3064 remiCodeFromeBBlock (ebp, ic);
3065 bitVectUnSetBit(OP_SYMBOL(IC_RESULT(ic))->defs,ic->key);
3066 hTabDeleteItem (&iCodehTab, ic->key, ic, DELETE_ITEM, NULL);
3067 OP_DEFS(IC_RESULT (dic))=bitVectSetBit (OP_DEFS (IC_RESULT (dic)), dic->key);
3075 iTempNN := (some variable in farspace) V1
3080 if (ic->op == IPUSH)
3082 packForPush (ic, ebpp, blockno);
3086 /* pack registers for accumulator use, when the
3087 result of an arithmetic or bit wise operation
3088 has only one use, that use is immediately following
3089 the defintion and the using iCode has only one
3090 operand or has two operands but one is literal &
3091 the result of that operation is not on stack then
3092 we can leave the result of this operation in acc:b
3094 if ((IS_ARITHMETIC_OP (ic)
3095 || IS_CONDITIONAL(ic)
3096 || IS_BITWISE_OP (ic)
3097 || ic->op == LEFT_OP || ic->op == RIGHT_OP || ic->op == CALL
3098 || (ic->op == ADDRESS_OF && isOperandOnStack (IC_LEFT (ic)))
3100 IS_ITEMP (IC_RESULT (ic)) &&
3101 getSize (operandType (IC_RESULT (ic))) <= 2)
3103 packRegsForAccUse (ic);
3107 /*-----------------------------------------------------------------*/
3108 /* assignRegisters - assigns registers to each live range as need */
3109 /*-----------------------------------------------------------------*/
3111 mcs51_assignRegisters (eBBlock ** ebbs, int count)
3116 setToNull ((void *) &_G.funcrUsed);
3117 setToNull ((void *) &_G.regAssigned);
3118 setToNull ((void *) &_G.totRegAssigned);
3119 mcs51_ptrRegReq = _G.stackExtend = _G.dataExtend = 0;
3122 /* change assignments this will remove some
3123 live ranges reducing some register pressure */
3125 for (i = 0; i < count; i++)
3126 packRegisters (ebbs, i);
3128 /* liveranges probably changed by register packing
3129 so we compute them again */
3130 recomputeLiveRanges (ebbs, count);
3132 if (options.dump_pack)
3133 dumpEbbsToFileExt (DUMP_PACK, ebbs, count);
3135 /* first determine for each live range the number of
3136 registers & the type of registers required for each */
3139 /* and serially allocate registers */
3140 serialRegAssign (ebbs, count);
3143 //setToNull ((void *) &_G.regAssigned);
3144 //setToNull ((void *) &_G.totRegAssigned);
3147 /* if stack was extended then tell the user */
3150 /* werror(W_TOOMANY_SPILS,"stack", */
3151 /* _G.stackExtend,currFunc->name,""); */
3157 /* werror(W_TOOMANY_SPILS,"data space", */
3158 /* _G.dataExtend,currFunc->name,""); */
3162 /* after that create the register mask
3163 for each of the instruction */
3164 createRegMask (ebbs, count);
3166 /* redo that offsets for stacked automatic variables */
3168 redoStackOffsets ();
3171 /* make sure r0 & r1 are flagged as used if they might be used */
3173 if (currFunc && mcs51_ptrRegReq)
3175 currFunc->regsUsed = bitVectSetBit (currFunc->regsUsed, R0_IDX);
3176 currFunc->regsUsed = bitVectSetBit (currFunc->regsUsed, R1_IDX);
3179 if (options.dump_rassgn)
3181 dumpEbbsToFileExt (DUMP_RASSGN, ebbs, count);
3182 dumpLiveRanges (DUMP_LRANGE, liveRanges);
3185 /* do the overlaysegment stuff SDCCmem.c */
3186 doOverlays (ebbs, count);
3188 /* now get back the chain */
3189 ic = iCodeLabelOptimize (iCodeFromeBBlock (ebbs, count));
3193 /* free up any _G.stackSpil locations allocated */
3194 applyToSet (_G.stackSpil, deallocStackSpil);
3196 setToNull ((void *) &_G.stackSpil);
3197 setToNull ((void *) &_G.spiltSet);
3198 /* mark all registers as free */