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->regType == sym->regType && /* same register types */
985 result->nRegs && /* which needs registers */
986 !result->isspilt && /* and does not already have them */
988 !bitVectBitValue (_G.regAssigned, result->key) &&
989 /* the number of free regs + number of regs in this LR
990 can accomodate the what result Needs */
991 ((nfreeRegsType (result->regType) +
992 sym->nRegs) >= result->nRegs)
996 for (i = 0; i < result->nRegs; i++)
998 result->regs[i] = sym->regs[i];
1000 result->regs[i] = getRegGpr (ic, ebp, result);
1002 _G.regAssigned = bitVectSetBit (_G.regAssigned, result->key);
1003 _G.totRegAssigned = bitVectSetBit (_G.totRegAssigned, result->key);
1007 /* free the remaining */
1008 for (; i < sym->nRegs; i++)
1012 if (!symHasReg (psym, sym->regs[i]))
1013 freeReg (sym->regs[i]);
1016 freeReg (sym->regs[i]);
1023 /*-----------------------------------------------------------------*/
1024 /* reassignLR - reassign this to registers */
1025 /*-----------------------------------------------------------------*/
1027 reassignLR (operand * op)
1029 symbol *sym = OP_SYMBOL (op);
1032 /* not spilt any more */
1033 sym->isspilt = sym->spillA = sym->blockSpil = sym->remainSpil = 0;
1034 bitVectUnSetBit (_G.spiltSet, sym->key);
1036 _G.regAssigned = bitVectSetBit (_G.regAssigned, sym->key);
1037 _G.totRegAssigned = bitVectSetBit (_G.totRegAssigned, sym->key);
1041 for (i = 0; i < sym->nRegs; i++)
1042 sym->regs[i]->isFree = 0;
1045 /*-----------------------------------------------------------------*/
1046 /* willCauseSpill - determines if allocating will cause a spill */
1047 /*-----------------------------------------------------------------*/
1049 willCauseSpill (int nr, int rt)
1051 /* first check if there are any avlb registers
1052 of te type required */
1055 /* special case for pointer type
1056 if pointer type not avlb then
1057 check for type gpr */
1058 if (nFreeRegs (rt) >= nr)
1060 if (nFreeRegs (REG_GPR) >= nr)
1065 if (mcs51_ptrRegReq)
1067 if (nFreeRegs (rt) >= nr)
1072 if (nFreeRegs (REG_PTR) +
1073 nFreeRegs (REG_GPR) >= nr)
1078 /* it will cause a spil */
1082 /*-----------------------------------------------------------------*/
1083 /* positionRegs - the allocator can allocate same registers to res- */
1084 /* ult and operand, if this happens make sure they are in the same */
1085 /* position as the operand otherwise chaos results */
1086 /*-----------------------------------------------------------------*/
1088 positionRegs (symbol * result, symbol * opsym)
1090 int count = min (result->nRegs, opsym->nRegs);
1091 int i, j = 0, shared = 0;
1094 /* if the result has been spilt then cannot share */
1099 /* first make sure that they actually share */
1100 for (i = 0; i < count; i++)
1102 for (j = 0; j < count; j++)
1104 if (result->regs[i] == opsym->regs[j] && i != j)
1114 regs *tmp = result->regs[i];
1115 result->regs[i] = result->regs[j];
1116 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);
1150 /*-----------------------------------------------------------------*/
1151 /* serialRegAssign - serially allocate registers to the variables */
1152 /*-----------------------------------------------------------------*/
1154 serialRegAssign (eBBlock ** ebbs, int count)
1158 /* for all blocks */
1159 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) {
1173 // update the registers in use at the start of this icode
1174 for (reg=0; reg<mcs51_nRegs; reg++) {
1175 if (regs8051[reg].isFree) {
1176 ic->riu &= ~(1<<regs8051[reg].offset);
1178 ic->riu |= (1<<regs8051[reg].offset);
1182 /* if this is an ipop that means some live
1183 range will have to be assigned again */
1185 reassignLR (IC_LEFT (ic));
1187 /* if result is present && is a true symbol */
1188 if (IC_RESULT (ic) && ic->op != IFX &&
1189 IS_TRUE_SYMOP (IC_RESULT (ic)))
1190 OP_SYMBOL (IC_RESULT (ic))->allocreq++;
1192 /* take away registers from live
1193 ranges that end at this instruction */
1194 deassignLRs (ic, ebbs[i]);
1196 /* some don't need registers */
1197 if (SKIP_IC2 (ic) ||
1198 ic->op == JUMPTABLE ||
1202 (IC_RESULT (ic) && POINTER_SET (ic)))
1205 /* now we need to allocate registers
1206 only for the result */
1207 if (IC_RESULT (ic)) {
1208 symbol *sym = OP_SYMBOL (IC_RESULT (ic));
1214 /* if it does not need or is spilt
1215 or is already assigned to registers
1216 or will not live beyond this instructions */
1219 bitVectBitValue (_G.regAssigned, sym->key) ||
1220 sym->liveTo <= ic->seq)
1223 /* if some liverange has been spilt at the block level
1224 and this one live beyond this block then spil this
1226 if (_G.blockSpil && sym->liveTo > ebbs[i]->lSeq) {
1230 /* if trying to allocate this will cause
1231 a spill and there is nothing to spill
1232 or this one is rematerializable then
1234 willCS = willCauseSpill (sym->nRegs, sym->regType);
1235 spillable = computeSpillable (ic);
1236 if (sym->remat || (willCS && bitVectIsZero (spillable))) {
1241 /* If the live range preceeds the point of definition
1242 then ideally we must take into account registers that
1243 have been allocated after sym->liveFrom but freed
1244 before ic->seq. This is complicated, so spill this
1245 symbol instead and let fillGaps handle the allocation. */
1246 if (sym->liveFrom < ic->seq) {
1251 /* if it has a spillocation & is used less than
1252 all other live ranges then spill this */
1254 if (sym->usl.spillLoc) {
1255 symbol *leastUsed = leastUsedLR (liveRangesWith (spillable,
1256 allLRs, ebbs[i], ic));
1257 if (leastUsed && leastUsed->used > sym->used) {
1262 /* if none of the liveRanges have a spillLocation then better
1263 to spill this one than anything else already assigned to registers */
1264 if (liveRangesWith(spillable,noSpilLoc,ebbs[i],ic)) {
1265 /* if this is local to this block then we might find a block spil */
1266 if (!(sym->liveFrom >= ebbs[i]->fSeq && sym->liveTo <= ebbs[i]->lSeq)) {
1273 /* if we need ptr regs for the right side
1275 if (POINTER_GET (ic) && IS_SYMOP (IC_LEFT (ic))
1276 && getSize (OP_SYMBOL (IC_LEFT (ic))->type) <= (unsigned int) PTRSIZE) {
1280 if (IC_LEFT (ic) && IS_SYMOP (IC_LEFT (ic))
1281 && SPEC_OCLS(OP_SYMBOL (IC_LEFT (ic))->etype) == idata) {
1285 if (IC_RIGHT (ic) && IS_SYMOP (IC_RIGHT (ic))
1286 && SPEC_OCLS(OP_SYMBOL (IC_RIGHT (ic))->etype) == idata) {
1291 /* else we assign registers to it */
1292 _G.regAssigned = bitVectSetBit (_G.regAssigned, sym->key);
1293 _G.totRegAssigned = bitVectSetBit (_G.totRegAssigned, sym->key);
1295 for (j = 0; j < sym->nRegs; j++) {
1296 sym->regs[j] = NULL;
1297 if (sym->regType == REG_PTR)
1298 sym->regs[j] = getRegPtr (ic, ebbs[i], sym);
1301 if (ic->op == CAST && IS_SYMOP (IC_RIGHT (ic)))
1303 symbol * right = OP_SYMBOL (IC_RIGHT (ic));
1306 sym->regs[j] = allocThisReg (right->regs[j]);
1309 sym->regs[j] = getRegGpr (ic, ebbs[i], sym);
1312 /* if the allocation failed which means
1313 this was spilt then break */
1316 for (i=0; i < sym->nRegs ; i++ )
1317 sym->regs[i] = NULL;
1322 if (!POINTER_SET(ic) && !POINTER_GET(ic)) {
1323 /* if it shares registers with operands make sure
1324 that they are in the same position */
1325 if (IC_LEFT (ic) && IS_SYMOP (IC_LEFT (ic)) &&
1326 OP_SYMBOL (IC_LEFT (ic))->nRegs) {
1327 positionRegs (OP_SYMBOL (IC_RESULT (ic)),
1328 OP_SYMBOL (IC_LEFT (ic)));
1330 /* do the same for the right operand */
1331 if (IC_RIGHT (ic) && IS_SYMOP (IC_RIGHT (ic)) &&
1332 OP_SYMBOL (IC_RIGHT (ic))->nRegs) {
1333 positionRegs (OP_SYMBOL (IC_RESULT (ic)),
1334 OP_SYMBOL (IC_RIGHT (ic)));
1347 /* Check for and fix any problems with uninitialized operands */
1348 for (i = 0; i < count; i++)
1352 if (ebbs[i]->noPath &&
1353 (ebbs[i]->entryLabel != entryLabel &&
1354 ebbs[i]->entryLabel != returnLabel))
1357 for (ic = ebbs[i]->sch; ic; ic = ic->next)
1364 verifyRegsAssigned (IC_COND (ic), ic);
1368 if (ic->op == JUMPTABLE)
1370 verifyRegsAssigned (IC_JTCOND (ic), ic);
1374 verifyRegsAssigned (IC_RESULT (ic), ic);
1375 verifyRegsAssigned (IC_LEFT (ic), ic);
1376 verifyRegsAssigned (IC_RIGHT (ic), ic);
1381 /*-----------------------------------------------------------------*/
1382 /* fillGaps - Try to fill in the Gaps left by Pass1 */
1383 /*-----------------------------------------------------------------*/
1384 static void fillGaps()
1391 if (getenv("DISABLE_FILL_GAPS")) return;
1393 /* look for livernages that was spilt by the allocator */
1394 for (sym = hTabFirstItem(liveRanges,&key) ; sym ;
1395 sym = hTabNextItem(liveRanges,&key)) {
1400 if (!sym->spillA || !sym->clashes || sym->remat) continue ;
1402 /* find the liveRanges this one clashes with, that are
1403 still assigned to registers & mark the registers as used*/
1404 for ( i = 0 ; i < sym->clashes->size ; i ++) {
1408 if (bitVectBitValue(sym->clashes,i) == 0 || /* those that clash with this */
1409 bitVectBitValue(_G.totRegAssigned,i) == 0) /* and are still assigned to registers */
1412 clr = hTabItemWithKey(liveRanges,i);
1415 /* mark these registers as used */
1416 for (k = 0 ; k < clr->nRegs ; k++ )
1417 useReg(clr->regs[k]);
1420 if (willCauseSpill(sym->nRegs,sym->regType)) {
1421 /* NOPE :( clear all registers & and continue */
1427 for (i = 0 ; i < sym->defs->size ; i++ )
1429 if (bitVectBitValue(sym->defs,i))
1431 if (!(ic = hTabItemWithKey(iCodehTab,i)))
1438 D(printf("Atemping fillGaps on %s: [",sym->name));
1439 /* THERE IS HOPE !!!! */
1440 for (i=0; i < sym->nRegs ; i++ ) {
1441 if (sym->regType == REG_PTR)
1442 sym->regs[i] = getRegPtrNoSpil ();
1445 sym->regs[i] = NULL;
1446 if (ic && ic->op == CAST && IS_SYMOP (IC_RIGHT (ic)))
1448 symbol * right = OP_SYMBOL (IC_RIGHT (ic));
1451 sym->regs[i] = allocThisReg (right->regs[i]);
1454 sym->regs[i] = getRegGprNoSpil ();
1456 D(printf("%s ", sym->regs[i]->name));
1460 /* For all its definitions check if the registers
1461 allocated needs positioning NOTE: we can position
1462 only ONCE if more than One positioning required
1464 We may need to perform the checks twice; once to
1465 position the registers as needed, the second to
1466 verify any register repositioning is still
1470 for (pass=0; pass<2; pass++) {
1471 D(printf(" checking definitions\n"));
1472 for (i = 0 ; i < sym->defs->size ; i++ ) {
1473 if (bitVectBitValue(sym->defs,i)) {
1474 if (!(ic = hTabItemWithKey(iCodehTab,i))) continue ;
1475 D(printf(" ic->seq = %d\n", ic->seq));
1476 if (SKIP_IC(ic)) continue;
1477 assert(isSymbolEqual(sym,OP_SYMBOL(IC_RESULT(ic)))); /* just making sure */
1478 /* if left is assigned to registers */
1479 if (IS_SYMOP(IC_LEFT(ic)))
1481 D(printf(" left = "));
1482 D(printOperand(IC_LEFT(ic),NULL));
1484 if (IS_SYMOP(IC_LEFT(ic)) &&
1485 bitVectBitValue(_G.totRegAssigned,OP_SYMBOL(IC_LEFT(ic))->key)) {
1486 pdone += (positionRegs(sym,OP_SYMBOL(IC_LEFT(ic)))>0);
1488 if (IS_SYMOP(IC_RIGHT(ic)))
1490 D(printf(" right = "));
1491 D(printOperand(IC_RIGHT(ic),NULL));
1493 if (IS_SYMOP(IC_RIGHT(ic)) &&
1494 bitVectBitValue(_G.totRegAssigned,OP_SYMBOL(IC_RIGHT(ic))->key)) {
1495 pdone += (positionRegs(sym,OP_SYMBOL(IC_RIGHT(ic)))>0);
1497 D(printf(" pdone = %d\n", pdone));
1498 if (pdone > 1) break;
1501 D(printf(" checking uses\n"));
1502 for (i = 0 ; i < sym->uses->size ; i++ ) {
1503 if (bitVectBitValue(sym->uses,i)) {
1505 if (!(ic = hTabItemWithKey(iCodehTab,i))) continue ;
1506 D(printf(" ic->seq = %d\n", ic->seq));
1507 if (SKIP_IC(ic)) continue;
1508 if (POINTER_SET(ic) || POINTER_GET(ic)) continue ;
1510 /* if result is assigned to registers */
1511 if (IS_SYMOP(IC_RESULT(ic)))
1513 D(printf(" result = "));
1514 D(printOperand(IC_RESULT(ic),NULL));
1516 if (IS_SYMOP(IC_RESULT(ic)) &&
1517 bitVectBitValue(_G.totRegAssigned,OP_SYMBOL(IC_RESULT(ic))->key)) {
1518 pdone += (positionRegs(sym,OP_SYMBOL(IC_RESULT(ic)))>0);
1520 D(printf(" pdone = %d\n", pdone));
1521 if (pdone > 1) break;
1524 if (pdone == 0) break; /* second pass only if regs repositioned */
1525 if (pdone > 1) break;
1527 D(printf(" sym->regs = ["));
1528 for (i=0; i < sym->nRegs ; i++ )
1529 D(printf("%s ", sym->regs[i]->name));
1531 /* had to position more than once GIVE UP */
1533 /* UNDO all the changes we made to try this */
1535 for (i=0; i < sym->nRegs ; i++ ) {
1536 sym->regs[i] = NULL;
1539 D(printf ("Fill Gap gave up due to positioning for %s in function %s\n",sym->name, currFunc ? currFunc->name : "UNKNOWN"));
1542 D(printf ("FILLED GAP for %s in function %s\n",sym->name, currFunc ? currFunc->name : "UNKNOWN"));
1544 _G.totRegAssigned = bitVectSetBit(_G.totRegAssigned,sym->key);
1545 sym->isspilt = sym->spillA = 0 ;
1546 sym->usl.spillLoc->allocreq--;
1551 /*-----------------------------------------------------------------*/
1552 /* rUmaskForOp :- returns register mask for an operand */
1553 /*-----------------------------------------------------------------*/
1555 mcs51_rUmaskForOp (operand * op)
1561 /* only temporaries are assigned registers */
1565 sym = OP_SYMBOL (op);
1567 /* if spilt or no registers assigned to it
1569 if (sym->isspilt || !sym->nRegs)
1572 rumask = newBitVect (mcs51_nRegs);
1574 for (j = 0; j < sym->nRegs; j++)
1576 if (sym->regs[j]) /* EEP - debug */
1577 rumask = bitVectSetBit (rumask,
1578 sym->regs[j]->rIdx);
1584 /*-----------------------------------------------------------------*/
1585 /* regsUsedIniCode :- returns bit vector of registers used in iCode */
1586 /*-----------------------------------------------------------------*/
1588 regsUsedIniCode (iCode * ic)
1590 bitVect *rmask = newBitVect (mcs51_nRegs);
1592 /* do the special cases first */
1595 rmask = bitVectUnion (rmask,
1596 mcs51_rUmaskForOp (IC_COND (ic)));
1600 /* for the jumptable */
1601 if (ic->op == JUMPTABLE)
1603 rmask = bitVectUnion (rmask,
1604 mcs51_rUmaskForOp (IC_JTCOND (ic)));
1609 /* of all other cases */
1611 rmask = bitVectUnion (rmask,
1612 mcs51_rUmaskForOp (IC_LEFT (ic)));
1616 rmask = bitVectUnion (rmask,
1617 mcs51_rUmaskForOp (IC_RIGHT (ic)));
1620 rmask = bitVectUnion (rmask,
1621 mcs51_rUmaskForOp (IC_RESULT (ic)));
1627 /*-----------------------------------------------------------------*/
1628 /* createRegMask - for each instruction will determine the regsUsed */
1629 /*-----------------------------------------------------------------*/
1631 createRegMask (eBBlock ** ebbs, int count)
1635 /* for all blocks */
1636 for (i = 0; i < count; i++)
1640 if (ebbs[i]->noPath &&
1641 (ebbs[i]->entryLabel != entryLabel &&
1642 ebbs[i]->entryLabel != returnLabel))
1645 /* for all instructions */
1646 for (ic = ebbs[i]->sch; ic; ic = ic->next)
1651 if (SKIP_IC2 (ic) || !ic->rlive)
1654 /* first mark the registers used in this
1656 ic->rUsed = regsUsedIniCode (ic);
1657 _G.funcrUsed = bitVectUnion (_G.funcrUsed, ic->rUsed);
1659 /* now create the register mask for those
1660 registers that are in use : this is a
1661 super set of ic->rUsed */
1662 ic->rMask = newBitVect (mcs51_nRegs + 1);
1664 /* for all live Ranges alive at this point */
1665 for (j = 1; j < ic->rlive->size; j++)
1670 /* if not alive then continue */
1671 if (!bitVectBitValue (ic->rlive, j))
1674 /* find the live range we are interested in */
1675 if (!(sym = hTabItemWithKey (liveRanges, j)))
1677 werror (E_INTERNAL_ERROR, __FILE__, __LINE__,
1678 "createRegMask cannot find live range");
1679 fprintf(stderr, "\tmissing live range: key=%d\n", j);
1683 /* if no register assigned to it */
1684 if (!sym->nRegs || sym->isspilt)
1687 /* for all the registers allocated to it */
1688 for (k = 0; k < sym->nRegs; k++)
1691 bitVectSetBit (ic->rMask, sym->regs[k]->rIdx);
1697 /*-----------------------------------------------------------------*/
1698 /* rematStr - returns the rematerialized string for a remat var */
1699 /*-----------------------------------------------------------------*/
1701 rematStr (symbol * sym)
1704 iCode *ic = sym->rematiCode;
1709 /* if plus or minus print the right hand side */
1710 if (ic->op == '+' || ic->op == '-')
1712 sprintf (s, "0x%04x %c ", (int) operandLitValue (IC_RIGHT (ic)),
1715 ic = OP_SYMBOL (IC_LEFT (ic))->rematiCode;
1719 /* cast then continue */
1720 if (IS_CAST_ICODE(ic)) {
1721 ic = OP_SYMBOL (IC_RIGHT (ic))->rematiCode;
1724 /* we reached the end */
1725 sprintf (s, "%s", OP_SYMBOL (IC_LEFT (ic))->rname);
1732 /*-----------------------------------------------------------------*/
1733 /* regTypeNum - computes the type & number of registers required */
1734 /*-----------------------------------------------------------------*/
1736 regTypeNum (eBBlock *ebbs)
1742 /* for each live range do */
1743 for (sym = hTabFirstItem (liveRanges, &k); sym;
1744 sym = hTabNextItem (liveRanges, &k))
1747 /* if used zero times then no registers needed */
1748 if ((sym->liveTo - sym->liveFrom) == 0)
1752 /* if the live range is a temporary */
1756 /* if the type is marked as a conditional */
1757 if (sym->regType == REG_CND)
1760 /* if used in return only then we don't
1762 if (sym->ruonly || sym->accuse)
1764 if (IS_AGGREGATE (sym->type) || sym->isptr)
1765 sym->type = aggrToPtr (sym->type, FALSE);
1769 /* if the symbol has only one definition &
1770 that definition is a get_pointer */
1771 if (bitVectnBitsOn (sym->defs) == 1 &&
1772 (ic = hTabItemWithKey (iCodehTab,
1773 bitVectFirstBit (sym->defs))) &&
1775 !IS_BITVAR (sym->etype) &&
1776 (aggrToPtrDclType (operandType (IC_LEFT (ic)), FALSE) == POINTER))
1779 if (ptrPseudoSymSafe (sym, ic))
1781 ptrPseudoSymConvert (sym, ic, rematStr (OP_SYMBOL (IC_LEFT (ic))));
1785 /* if in data space or idata space then try to
1786 allocate pointer register */
1790 /* if not then we require registers */
1791 sym->nRegs = ((IS_AGGREGATE (sym->type) || sym->isptr) ?
1792 getSize (sym->type = aggrToPtr (sym->type, FALSE)) :
1793 getSize (sym->type));
1797 fprintf (stderr, "allocated more than 4 or 0 registers for type ");
1798 printTypeChain (sym->type, stderr);
1799 fprintf (stderr, "\n");
1802 /* determine the type of register required */
1803 if (sym->nRegs == 1 &&
1804 IS_PTR (sym->type) &&
1806 sym->regType = REG_PTR;
1808 sym->regType = REG_GPR;
1812 /* for the first run we don't provide */
1813 /* registers for true symbols we will */
1814 /* see how things go */
1820 /*-----------------------------------------------------------------*/
1821 /* freeAllRegs - mark all registers as free */
1822 /*-----------------------------------------------------------------*/
1828 for (i = 0; i < mcs51_nRegs; i++)
1829 regs8051[i].isFree = 1;
1832 /*-----------------------------------------------------------------*/
1833 /* deallocStackSpil - this will set the stack pointer back */
1834 /*-----------------------------------------------------------------*/
1836 DEFSETFUNC (deallocStackSpil)
1844 /*-----------------------------------------------------------------*/
1845 /* farSpacePackable - returns the packable icode for far variables */
1846 /*-----------------------------------------------------------------*/
1848 farSpacePackable (iCode * ic)
1852 /* go thru till we find a definition for the
1853 symbol on the right */
1854 for (dic = ic->prev; dic; dic = dic->prev)
1856 /* if the definition is a call then no */
1857 if ((dic->op == CALL || dic->op == PCALL) &&
1858 IC_RESULT (dic)->key == IC_RIGHT (ic)->key)
1863 /* if shift by unknown amount then not */
1864 if ((dic->op == LEFT_OP || dic->op == RIGHT_OP) &&
1865 IC_RESULT (dic)->key == IC_RIGHT (ic)->key)
1868 /* if pointer get and size > 1 */
1869 if (POINTER_GET (dic) &&
1870 getSize (aggrToPtr (operandType (IC_LEFT (dic)), FALSE)) > 1)
1873 if (POINTER_SET (dic) &&
1874 getSize (aggrToPtr (operandType (IC_RESULT (dic)), FALSE)) > 1)
1879 if (IC_COND (dic) &&
1880 IS_TRUE_SYMOP (IC_COND (dic)) &&
1881 isOperandInFarSpace (IC_COND (dic)))
1884 else if (dic->op == JUMPTABLE)
1886 if (IC_JTCOND (dic) &&
1887 IS_TRUE_SYMOP (IC_JTCOND (dic)) &&
1888 isOperandInFarSpace (IC_JTCOND (dic)))
1893 /* if any three is a true symbol in far space */
1894 if (IC_RESULT (dic) &&
1895 IS_TRUE_SYMOP (IC_RESULT (dic)) &&
1896 isOperandInFarSpace (IC_RESULT (dic)))
1899 if (IC_RIGHT (dic) &&
1900 IS_TRUE_SYMOP (IC_RIGHT (dic)) &&
1901 isOperandInFarSpace (IC_RIGHT (dic)) &&
1902 !isOperandEqual (IC_RIGHT (dic), IC_RESULT (ic)))
1905 if (IC_LEFT (dic) &&
1906 IS_TRUE_SYMOP (IC_LEFT (dic)) &&
1907 isOperandInFarSpace (IC_LEFT (dic)) &&
1908 !isOperandEqual (IC_LEFT (dic), IC_RESULT (ic)))
1912 if (isOperandEqual (IC_RIGHT (ic), IC_RESULT (dic)))
1914 if ((dic->op == LEFT_OP ||
1915 dic->op == RIGHT_OP ||
1917 IS_OP_LITERAL (IC_RIGHT (dic)))
1927 /*-----------------------------------------------------------------*/
1928 /* packRegsForAssign - register reduction for assignment */
1929 /*-----------------------------------------------------------------*/
1931 packRegsForAssign (iCode * ic, eBBlock * ebp)
1935 if (!IS_ITEMP (IC_RIGHT (ic)) ||
1936 OP_SYMBOL (IC_RIGHT (ic))->isind ||
1937 OP_LIVETO (IC_RIGHT (ic)) > ic->seq)
1942 /* if the true symbol is defined in far space or on stack
1943 then we should not since this will increase register pressure */
1944 if (isOperandInFarSpace(IC_RESULT(ic)) && !farSpacePackable(ic)) {
1948 /* find the definition of iTempNN scanning backwards if we find a
1949 a use of the true symbol in before we find the definition then
1951 for (dic = ic->prev; dic; dic = dic->prev)
1953 int crossedCall = 0;
1955 /* We can pack across a function call only if it's a local */
1956 /* variable or our parameter. Never pack global variables */
1957 /* or parameters to a function we call. */
1958 if ((dic->op == CALL || dic->op == PCALL))
1960 if (!OP_SYMBOL (IC_RESULT (ic))->ismyparm
1961 && !OP_SYMBOL (IC_RESULT (ic))->islocal)
1972 if (IS_SYMOP (IC_COND (dic)) &&
1973 (IC_COND (dic)->key == IC_RESULT (ic)->key ||
1974 IC_COND (dic)->key == IC_RIGHT (ic)->key))
1982 if (IS_TRUE_SYMOP (IC_RESULT (dic)) &&
1983 IS_OP_VOLATILE (IC_RESULT (dic)))
1989 if (IS_SYMOP (IC_RESULT (dic)) &&
1990 IC_RESULT (dic)->key == IC_RIGHT (ic)->key)
1992 if (POINTER_SET (dic))
1998 if (IS_SYMOP (IC_RIGHT (dic)) &&
1999 (IC_RIGHT (dic)->key == IC_RESULT (ic)->key ||
2000 IC_RIGHT (dic)->key == IC_RIGHT (ic)->key))
2006 if (IS_SYMOP (IC_LEFT (dic)) &&
2007 (IC_LEFT (dic)->key == IC_RESULT (ic)->key ||
2008 IC_LEFT (dic)->key == IC_RIGHT (ic)->key))
2014 if (IS_SYMOP (IC_RESULT (dic)) &&
2015 IC_RESULT (dic)->key == IC_RESULT (ic)->key)
2031 return 0; /* did not find */
2033 /* if assignment then check that right is not a bit */
2034 if (ASSIGNMENT (ic) && !POINTER_SET (ic))
2036 sym_link *etype = operandType (IC_RESULT (dic));
2037 if (IS_BITFIELD (etype))
2039 /* if result is a bit too then it's ok */
2040 etype = operandType (IC_RESULT (ic));
2041 if (!IS_BITFIELD (etype))
2048 /* if assignment then check that right is not a bit */
2049 if (ASSIGNMENT (dic) && !POINTER_SET (dic))
2051 sym_link *etype = operandType (IC_RIGHT (dic));
2052 if (IS_BITFIELD (etype))
2054 /* if result is a bit too then it's ok */
2055 etype = operandType (IC_RESULT (dic));
2056 if (!IS_BITFIELD (etype))
2061 /* if the result is on stack or iaccess then it must be
2062 the same atleast one of the operands */
2063 if (OP_SYMBOL (IC_RESULT (ic))->onStack ||
2064 OP_SYMBOL (IC_RESULT (ic))->iaccess)
2067 /* the operation has only one symbol
2068 operator then we can pack */
2069 if ((IC_LEFT (dic) && !IS_SYMOP (IC_LEFT (dic))) ||
2070 (IC_RIGHT (dic) && !IS_SYMOP (IC_RIGHT (dic))))
2073 if (!((IC_LEFT (dic) &&
2074 IC_RESULT (ic)->key == IC_LEFT (dic)->key) ||
2076 IC_RESULT (ic)->key == IC_RIGHT (dic)->key)))
2080 /* found the definition */
2081 /* replace the result with the result of */
2082 /* this assignment and remove this assignment */
2083 bitVectUnSetBit(OP_SYMBOL(IC_RESULT(dic))->defs,dic->key);
2084 ReplaceOpWithCheaperOp(&IC_RESULT (dic), IC_RESULT (ic));
2086 if (IS_ITEMP (IC_RESULT (dic)) && OP_SYMBOL (IC_RESULT (dic))->liveFrom > dic->seq)
2088 OP_SYMBOL (IC_RESULT (dic))->liveFrom = dic->seq;
2090 // TODO: and the otherway around?
2092 /* delete from liverange table also
2093 delete from all the points inbetween and the new
2095 for (sic = dic; sic != ic; sic = sic->next)
2097 bitVectUnSetBit (sic->rlive, IC_RESULT (ic)->key);
2098 if (IS_ITEMP (IC_RESULT (dic)))
2099 bitVectSetBit (sic->rlive, IC_RESULT (dic)->key);
2102 remiCodeFromeBBlock (ebp, ic);
2103 bitVectUnSetBit(OP_SYMBOL(IC_RESULT(ic))->defs,ic->key);
2104 hTabDeleteItem (&iCodehTab, ic->key, ic, DELETE_ITEM, NULL);
2105 OP_DEFS(IC_RESULT (dic))=bitVectSetBit (OP_DEFS (IC_RESULT (dic)), dic->key);
2109 /*------------------------------------------------------------------*/
2110 /* findAssignToSym : scanning backwards looks for first assig found */
2111 /*------------------------------------------------------------------*/
2113 findAssignToSym (operand * op, iCode * ic)
2117 /* This routine is used to find sequences like
2119 ...; (intervening ops don't use iTempAA or modify FOO)
2120 blah = blah + iTempAA;
2122 and eliminate the use of iTempAA, freeing up its register for
2126 for (dic = ic->prev; dic; dic = dic->prev)
2129 /* if definition by assignment */
2130 if (dic->op == '=' &&
2131 !POINTER_SET (dic) &&
2132 IC_RESULT (dic)->key == op->key
2133 /* && IS_TRUE_SYMOP(IC_RIGHT(dic)) */
2135 break; /* found where this temp was defined */
2137 /* if we find an usage then we cannot delete it */
2141 if (IC_COND (dic) && IC_COND (dic)->key == op->key)
2144 else if (dic->op == JUMPTABLE)
2146 if (IC_JTCOND (dic) && IC_JTCOND (dic)->key == op->key)
2151 if (IC_LEFT (dic) && IC_LEFT (dic)->key == op->key)
2154 if (IC_RIGHT (dic) && IC_RIGHT (dic)->key == op->key)
2157 if (POINTER_SET (dic) && IC_RESULT (dic)->key == op->key)
2163 return NULL; /* didn't find any assignment to op */
2165 /* we are interested only if defined in far space */
2166 /* or in stack space in case of + & - */
2168 /* if assigned to a non-symbol then don't repack regs */
2169 if (!IS_SYMOP (IC_RIGHT (dic)))
2172 /* if the symbol is volatile then we should not */
2173 if (isOperandVolatile (IC_RIGHT (dic), TRUE))
2175 /* XXX TODO --- should we be passing FALSE to isOperandVolatile()?
2176 What does it mean for an iTemp to be volatile, anyway? Passing
2177 TRUE is more cautious but may prevent possible optimizations */
2179 /* if the symbol is in far space then we should not */
2180 if (isOperandInFarSpace (IC_RIGHT (dic)))
2183 /* for + & - operations make sure that
2184 if it is on the stack it is the same
2185 as one of the three operands */
2186 if ((ic->op == '+' || ic->op == '-') &&
2187 OP_SYMBOL (IC_RIGHT (dic))->onStack)
2190 if (IC_RESULT (ic)->key != IC_RIGHT (dic)->key &&
2191 IC_LEFT (ic)->key != IC_RIGHT (dic)->key &&
2192 IC_RIGHT (ic)->key != IC_RIGHT (dic)->key)
2196 /* now make sure that the right side of dic
2197 is not defined between ic & dic */
2200 iCode *sic = dic->next;
2202 for (; sic != ic; sic = sic->next)
2203 if (IC_RESULT (sic) &&
2204 IC_RESULT (sic)->key == IC_RIGHT (dic)->key)
2211 /*-----------------------------------------------------------------*/
2212 /* reassignAliasedSym - used by packRegsForSupport to replace */
2213 /* redundant iTemp with equivalent symbol */
2214 /*-----------------------------------------------------------------*/
2216 reassignAliasedSym (eBBlock *ebp, iCode *assignment, iCode *use, operand *op)
2219 unsigned oldSymKey, newSymKey;
2221 oldSymKey = op->key;
2222 newSymKey = IC_RIGHT(assignment)->key;
2224 /* only track live ranges of compiler-generated temporaries */
2225 if (!IS_ITEMP(IC_RIGHT(assignment)))
2228 /* update the live-value bitmaps */
2229 for (ic = assignment; ic != use; ic = ic->next) {
2230 bitVectUnSetBit (ic->rlive, oldSymKey);
2232 ic->rlive = bitVectSetBit (ic->rlive, newSymKey);
2235 /* update the sym of the used operand */
2236 OP_SYMBOL(op) = OP_SYMBOL(IC_RIGHT(assignment));
2237 op->key = OP_SYMBOL(op)->key;
2238 OP_SYMBOL(op)->accuse = 0;
2240 /* update the sym's liverange */
2241 if ( OP_LIVETO(op) < ic->seq )
2242 setToRange(op, ic->seq, FALSE);
2244 /* remove the assignment iCode now that its result is unused */
2245 remiCodeFromeBBlock (ebp, assignment);
2246 bitVectUnSetBit(OP_SYMBOL(IC_RESULT(assignment))->defs, assignment->key);
2247 hTabDeleteItem (&iCodehTab, assignment->key, assignment, DELETE_ITEM, NULL);
2251 /*-----------------------------------------------------------------*/
2252 /* packRegsForSupport :- reduce some registers for support calls */
2253 /*-----------------------------------------------------------------*/
2255 packRegsForSupport (iCode * ic, eBBlock * ebp)
2259 /* for the left & right operand :- look to see if the
2260 left was assigned a true symbol in far space in that
2261 case replace them */
2263 if (IS_ITEMP (IC_LEFT (ic)) &&
2264 OP_SYMBOL (IC_LEFT (ic))->liveTo <= ic->seq)
2266 dic = findAssignToSym (IC_LEFT (ic), ic);
2270 /* found it we need to remove it from the block */
2271 reassignAliasedSym (ebp, dic, ic, IC_LEFT(ic));
2276 /* do the same for the right operand */
2277 if (IS_ITEMP (IC_RIGHT (ic)) &&
2278 OP_SYMBOL (IC_RIGHT (ic))->liveTo <= ic->seq)
2280 iCode *dic = findAssignToSym (IC_RIGHT (ic), ic);
2284 /* if this is a subtraction & the result
2285 is a true symbol in far space then don't pack */
2286 if (ic->op == '-' && IS_TRUE_SYMOP (IC_RESULT (dic)))
2288 sym_link *etype = getSpec (operandType (IC_RESULT (dic)));
2289 if (IN_FARSPACE (SPEC_OCLS (etype)))
2292 /* found it we need to remove it from the
2294 reassignAliasedSym (ebp, dic, ic, IC_RIGHT(ic));
2303 #define IS_OP_RUONLY(x) (x && IS_SYMOP(x) && OP_SYMBOL(x)->ruonly)
2306 /*-----------------------------------------------------------------*/
2307 /* packRegsForOneuse : - will reduce some registers for single Use */
2308 /*-----------------------------------------------------------------*/
2310 packRegsForOneuse (iCode * ic, operand * op, eBBlock * ebp)
2315 /* if returning a literal then do nothing */
2319 /* only upto 2 bytes since we cannot predict
2320 the usage of b, & acc */
2321 if (getSize (operandType (op)) > (fReturnSizeMCS51 - 2))
2324 if (ic->op != RETURN &&
2326 !POINTER_SET (ic) &&
2330 if (ic->op == SEND && ic->argreg != 1) return NULL;
2332 /* this routine will mark the a symbol as used in one
2333 instruction use only && if the defintion is local
2334 (ie. within the basic block) && has only one definition &&
2335 that definiion is either a return value from a
2336 function or does not contain any variables in
2338 uses = bitVectCopy (OP_USES (op));
2339 bitVectUnSetBit (uses, ic->key); /* take away this iCode */
2340 if (!bitVectIsZero (uses)) /* has other uses */
2343 /* if it has only one defintion */
2344 if (bitVectnBitsOn (OP_DEFS (op)) > 1)
2345 return NULL; /* has more than one definition */
2347 /* get that definition */
2349 hTabItemWithKey (iCodehTab,
2350 bitVectFirstBit (OP_DEFS (op)))))
2353 /* if that only usage is a cast */
2354 if (dic->op == CAST) {
2355 /* to a bigger type */
2356 if (getSize(OP_SYM_TYPE(IC_RESULT(dic))) >
2357 getSize(OP_SYM_TYPE(IC_RIGHT(dic)))) {
2358 /* than we can not, since we cannot predict the usage of b & acc */
2363 /* found the definition now check if it is local */
2364 if (dic->seq < ebp->fSeq ||
2365 dic->seq > ebp->lSeq)
2366 return NULL; /* non-local */
2368 /* now check if it is the return from
2370 if (dic->op == CALL || dic->op == PCALL)
2372 if (ic->op != SEND && ic->op != RETURN &&
2373 !POINTER_SET(ic) && !POINTER_GET(ic))
2375 OP_SYMBOL (op)->ruonly = 1;
2382 /* otherwise check that the definition does
2383 not contain any symbols in far space */
2384 if (isOperandInFarSpace (IC_LEFT (dic)) ||
2385 isOperandInFarSpace (IC_RIGHT (dic)) ||
2386 IS_OP_RUONLY (IC_LEFT (ic)) ||
2387 IS_OP_RUONLY (IC_RIGHT (ic)))
2392 /* if pointer set then make sure the pointer
2394 if (POINTER_SET (dic) &&
2395 !IS_DATA_PTR (aggrToPtr (operandType (IC_RESULT (dic)), FALSE)))
2398 if (POINTER_GET (dic) &&
2399 !IS_DATA_PTR (aggrToPtr (operandType (IC_LEFT (dic)), FALSE)))
2404 /* also make sure the intervenening instructions
2405 don't have any thing in far space */
2406 for (dic = dic->next; dic && dic != ic && sic != ic; dic = dic->next)
2409 /* if there is an intervening function call then no */
2410 if (dic->op == CALL || dic->op == PCALL)
2412 /* if pointer set then make sure the pointer
2414 if (POINTER_SET (dic) &&
2415 !IS_DATA_PTR (aggrToPtr (operandType (IC_RESULT (dic)), FALSE)))
2418 if (POINTER_GET (dic) &&
2419 !IS_DATA_PTR (aggrToPtr (operandType (IC_LEFT (dic)), FALSE)))
2422 /* if address of & the result is remat the okay */
2423 if (dic->op == ADDRESS_OF &&
2424 OP_SYMBOL (IC_RESULT (dic))->remat)
2427 /* if operand has size of three or more & this
2428 operation is a '*','/' or '%' then 'b' may
2430 if ((dic->op == '%' || dic->op == '/' || dic->op == '*') &&
2431 getSize (operandType (op)) >= 3)
2434 /* if left or right or result is in far space */
2435 if (isOperandInFarSpace (IC_LEFT (dic)) ||
2436 isOperandInFarSpace (IC_RIGHT (dic)) ||
2437 isOperandInFarSpace (IC_RESULT (dic)) ||
2438 IS_OP_RUONLY (IC_LEFT (dic)) ||
2439 IS_OP_RUONLY (IC_RIGHT (dic)) ||
2440 IS_OP_RUONLY (IC_RESULT (dic)))
2444 /* if left or right or result is on stack */
2445 if (isOperandOnStack(IC_LEFT(dic)) ||
2446 isOperandOnStack(IC_RIGHT(dic)) ||
2447 isOperandOnStack(IC_RESULT(dic))) {
2452 OP_SYMBOL (op)->ruonly = 1;
2456 /*-----------------------------------------------------------------*/
2457 /* isBitwiseOptimizable - requirements of JEAN LOUIS VERN */
2458 /*-----------------------------------------------------------------*/
2460 isBitwiseOptimizable (iCode * ic)
2462 sym_link *ltype = getSpec (operandType (IC_LEFT (ic)));
2463 sym_link *rtype = getSpec (operandType (IC_RIGHT (ic)));
2465 /* bitwise operations are considered optimizable
2466 under the following conditions (Jean-Louis VERN)
2478 if (IS_LITERAL(rtype) ||
2479 (IS_BITVAR (ltype) && IN_BITSPACE (SPEC_OCLS (ltype))))
2485 /*-----------------------------------------------------------------*/
2486 /* isCommutativeOp - tests whether this op cares what order its */
2487 /* operands are in */
2488 /*-----------------------------------------------------------------*/
2489 bool isCommutativeOp(unsigned int op)
2491 if (op == '+' || op == '*' || op == EQ_OP ||
2492 op == '^' || op == '|' || op == BITWISEAND)
2498 /*-----------------------------------------------------------------*/
2499 /* operandUsesAcc - determines whether the code generated for this */
2500 /* operand will have to use the accumulator */
2501 /*-----------------------------------------------------------------*/
2502 bool operandUsesAcc(operand *op)
2508 symbol *sym = OP_SYMBOL(op);
2512 return TRUE; /* duh! */
2514 if (IN_STACK(sym->etype) || sym->onStack ||
2515 (SPIL_LOC(op) && SPIL_LOC(op)->onStack))
2516 return TRUE; /* acc is used to calc stack offset */
2521 sym = SPIL_LOC(op); /* if spilled, look at spill location */
2523 return FALSE; /* more checks? */
2527 symspace = SPEC_OCLS(sym->etype);
2529 if (sym->iaccess && symspace->paged)
2530 return TRUE; /* must fetch paged indirect sym via accumulator */
2532 if (IN_BITSPACE(symspace))
2533 return TRUE; /* fetching bit vars uses the accumulator */
2535 if (IN_FARSPACE(symspace) || IN_CODESPACE(symspace))
2536 return TRUE; /* fetched via accumulator and dptr */
2542 /*-----------------------------------------------------------------*/
2543 /* packRegsForAccUse - pack registers for acc use */
2544 /*-----------------------------------------------------------------*/
2546 packRegsForAccUse (iCode * ic)
2550 /* if this is an aggregate, e.g. a one byte char array */
2551 if (IS_AGGREGATE(operandType(IC_RESULT(ic)))) {
2555 /* if we are calling a reentrant function that has stack parameters */
2556 if (ic->op == CALL &&
2557 IFFUNC_ISREENT(operandType(IC_LEFT(ic))) &&
2558 FUNC_HASSTACKPARM(operandType(IC_LEFT(ic))))
2561 if (ic->op == PCALL &&
2562 IFFUNC_ISREENT(operandType(IC_LEFT(ic))->next) &&
2563 FUNC_HASSTACKPARM(operandType(IC_LEFT(ic))->next))
2566 /* if + or - then it has to be one byte result */
2567 if ((ic->op == '+' || ic->op == '-')
2568 && getSize (operandType (IC_RESULT (ic))) > 1)
2571 /* if shift operation make sure right side is not a literal */
2572 if (ic->op == RIGHT_OP &&
2573 (isOperandLiteral (IC_RIGHT (ic)) ||
2574 getSize (operandType (IC_RESULT (ic))) > 1))
2577 if (ic->op == LEFT_OP &&
2578 (isOperandLiteral (IC_RIGHT (ic)) ||
2579 getSize (operandType (IC_RESULT (ic))) > 1))
2582 if (IS_BITWISE_OP (ic) &&
2583 getSize (operandType (IC_RESULT (ic))) > 1)
2587 /* has only one definition */
2588 if (bitVectnBitsOn (OP_DEFS (IC_RESULT (ic))) > 1)
2591 /* has only one use */
2592 if (bitVectnBitsOn (OP_USES (IC_RESULT (ic))) > 1)
2595 /* and the usage immediately follows this iCode */
2596 if (!(uic = hTabItemWithKey (iCodehTab,
2597 bitVectFirstBit (OP_USES (IC_RESULT (ic))))))
2600 if (ic->next != uic)
2603 /* if it is a conditional branch then we definitely can */
2607 if (uic->op == JUMPTABLE)
2610 if (POINTER_SET (uic) &&
2611 getSize (aggrToPtr (operandType (IC_RESULT (uic)), FALSE)) > 1)
2614 /* if the usage is not is an assignment
2615 or an arithmetic / bitwise / shift operation then not */
2616 if (uic->op != '=' &&
2617 !IS_ARITHMETIC_OP (uic) &&
2618 !IS_BITWISE_OP (uic) &&
2619 uic->op != LEFT_OP &&
2620 uic->op != RIGHT_OP)
2623 /* if used in ^ operation then make sure right is not a
2624 literal (WIML: Why is this?) */
2625 if (uic->op == '^' && isOperandLiteral (IC_RIGHT (uic)))
2628 /* if shift operation make sure right side is not a literal */
2629 /* WIML: Why is this? */
2630 if (uic->op == RIGHT_OP &&
2631 (isOperandLiteral (IC_RIGHT (uic)) ||
2632 getSize (operandType (IC_RESULT (uic))) > 1))
2634 if (uic->op == LEFT_OP &&
2635 (isOperandLiteral (IC_RIGHT (uic)) ||
2636 getSize (operandType (IC_RESULT (uic))) > 1))
2639 /* make sure that the result of this icode is not on the
2640 stack, since acc is used to compute stack offset */
2642 if (IS_TRUE_SYMOP (IC_RESULT (uic)) &&
2643 OP_SYMBOL (IC_RESULT (uic))->onStack)
2646 if (isOperandOnStack(IC_RESULT(uic)))
2650 /* if the usage has only one operand then we can */
2651 if (IC_LEFT (uic) == NULL ||
2652 IC_RIGHT (uic) == NULL)
2655 /* if the other operand uses the accumulator then we cannot */
2656 if ( (IC_LEFT(uic)->key == IC_RESULT(ic)->key &&
2657 operandUsesAcc(IC_RIGHT(uic))) ||
2658 (IC_RIGHT(uic)->key == IC_RESULT(ic)->key &&
2659 operandUsesAcc(IC_LEFT(uic))) )
2662 /* make sure this is on the left side if not commutative */
2663 /* except for '-', which has been written to be able to
2664 handle reversed operands */
2665 if (!(isCommutativeOp(ic->op) || ic->op == '-') &&
2666 IC_LEFT (uic)->key != IC_RESULT (ic)->key)
2670 // this is too dangerous and need further restrictions
2673 /* if one of them is a literal then we can */
2674 if ((IC_LEFT (uic) && IS_OP_LITERAL (IC_LEFT (uic))) ||
2675 (IC_RIGHT (uic) && IS_OP_LITERAL (IC_RIGHT (uic))))
2677 OP_SYMBOL (IC_RESULT (ic))->accuse = 1;
2683 OP_SYMBOL (IC_RESULT (ic))->accuse = 1;
2687 /*-----------------------------------------------------------------*/
2688 /* packForPush - hueristics to reduce iCode for pushing */
2689 /*-----------------------------------------------------------------*/
2691 packForPush (iCode * ic, eBBlock ** ebpp, int blockno)
2695 struct eBBlock * ebp=ebpp[blockno];
2697 if (ic->op != IPUSH || !IS_ITEMP (IC_LEFT (ic)))
2700 /* must have only definition & one usage */
2701 if (bitVectnBitsOn (OP_DEFS (IC_LEFT (ic))) != 1 ||
2702 bitVectnBitsOn (OP_USES (IC_LEFT (ic))) != 1)
2705 /* find the definition */
2706 if (!(dic = hTabItemWithKey (iCodehTab,
2707 bitVectFirstBit (OP_DEFS (IC_LEFT (ic))))))
2710 if (dic->op != '=' || POINTER_SET (dic))
2713 if (dic->seq < ebp->fSeq) { // Evelyn did this
2715 for (i=0; i<blockno; i++) {
2716 if (dic->seq >= ebpp[i]->fSeq && dic->seq <= ebpp[i]->lSeq) {
2721 wassert (i!=blockno); // no way to recover from here
2724 if (IS_SYMOP(IC_RIGHT(dic))) {
2725 /* make sure the right side does not have any definitions
2727 dbv = OP_DEFS(IC_RIGHT(dic));
2728 for (lic = ic; lic && lic != dic ; lic = lic->prev) {
2729 if (bitVectBitValue(dbv,lic->key))
2732 /* make sure they have the same type */
2733 if (IS_SPEC(operandType(IC_LEFT(ic))))
2735 sym_link *itype=operandType(IC_LEFT(ic));
2736 sym_link *ditype=operandType(IC_RIGHT(dic));
2738 if (SPEC_USIGN(itype)!=SPEC_USIGN(ditype) ||
2739 SPEC_LONG(itype)!=SPEC_LONG(ditype))
2742 /* extend the live range of replaced operand if needed */
2743 if (OP_SYMBOL(IC_RIGHT(dic))->liveTo < ic->seq) {
2744 OP_SYMBOL(IC_RIGHT(dic))->liveTo = ic->seq;
2746 bitVectUnSetBit(OP_SYMBOL(IC_RESULT(dic))->defs,dic->key);
2749 /* we now we know that it has one & only one def & use
2750 and the that the definition is an assignment */
2751 ReplaceOpWithCheaperOp(&IC_LEFT (ic), IC_RIGHT (dic));
2752 remiCodeFromeBBlock (ebp, dic);
2753 hTabDeleteItem (&iCodehTab, dic->key, dic, DELETE_ITEM, NULL);
2756 /*-----------------------------------------------------------------*/
2757 /* packRegisters - does some transformations to reduce register */
2759 /*-----------------------------------------------------------------*/
2761 packRegisters (eBBlock ** ebpp, int blockno)
2765 eBBlock *ebp=ebpp[blockno];
2772 /* look for assignments of the form */
2773 /* iTempNN = TRueSym (someoperation) SomeOperand */
2775 /* TrueSym := iTempNN:1 */
2776 for (ic = ebp->sch; ic; ic = ic->next)
2778 /* find assignment of the form TrueSym := iTempNN:1 */
2779 if (ic->op == '=' && !POINTER_SET (ic))
2780 change += packRegsForAssign (ic, ebp);
2787 for (ic = ebp->sch; ic; ic = ic->next)
2789 /* if this is an itemp & result of an address of a true sym
2790 then mark this as rematerialisable */
2791 if (ic->op == ADDRESS_OF &&
2792 IS_ITEMP (IC_RESULT (ic)) &&
2793 IS_TRUE_SYMOP (IC_LEFT (ic)) &&
2794 bitVectnBitsOn (OP_DEFS (IC_RESULT (ic))) == 1 &&
2795 !OP_SYMBOL (IC_LEFT (ic))->onStack)
2798 OP_SYMBOL (IC_RESULT (ic))->remat = 1;
2799 OP_SYMBOL (IC_RESULT (ic))->rematiCode = ic;
2800 OP_SYMBOL (IC_RESULT (ic))->usl.spillLoc = NULL;
2804 /* if straight assignment then carry remat flag if
2805 this is the only definition */
2806 if (ic->op == '=' &&
2807 !POINTER_SET (ic) &&
2808 IS_SYMOP (IC_RIGHT (ic)) &&
2809 OP_SYMBOL (IC_RIGHT (ic))->remat &&
2810 !IS_CAST_ICODE(OP_SYMBOL (IC_RIGHT (ic))->rematiCode) &&
2811 bitVectnBitsOn (OP_SYMBOL (IC_RESULT (ic))->defs) <= 1)
2814 OP_SYMBOL (IC_RESULT (ic))->remat =
2815 OP_SYMBOL (IC_RIGHT (ic))->remat;
2816 OP_SYMBOL (IC_RESULT (ic))->rematiCode =
2817 OP_SYMBOL (IC_RIGHT (ic))->rematiCode;
2820 /* if cast to a generic pointer & the pointer being
2821 cast is remat, then we can remat this cast as well */
2822 if (ic->op == CAST &&
2823 IS_SYMOP(IC_RIGHT(ic)) &&
2824 OP_SYMBOL(IC_RIGHT(ic))->remat &&
2825 bitVectnBitsOn (OP_DEFS (IC_RESULT (ic))) == 1) {
2826 sym_link *to_type = operandType(IC_LEFT(ic));
2827 sym_link *from_type = operandType(IC_RIGHT(ic));
2828 if (IS_GENPTR(to_type) && IS_PTR(from_type)) {
2829 OP_SYMBOL (IC_RESULT (ic))->remat = 1;
2830 OP_SYMBOL (IC_RESULT (ic))->rematiCode = ic;
2831 OP_SYMBOL (IC_RESULT (ic))->usl.spillLoc = NULL;
2835 /* if this is a +/- operation with a rematerizable
2836 then mark this as rematerializable as well */
2837 if ((ic->op == '+' || ic->op == '-') &&
2838 (IS_SYMOP (IC_LEFT (ic)) &&
2839 IS_ITEMP (IC_RESULT (ic)) &&
2840 IS_OP_LITERAL (IC_RIGHT (ic))) &&
2841 OP_SYMBOL (IC_LEFT (ic))->remat &&
2842 (!IS_SYMOP (IC_RIGHT (ic)) || !IS_CAST_ICODE(OP_SYMBOL (IC_RIGHT (ic))->rematiCode)) &&
2843 bitVectnBitsOn (OP_DEFS (IC_RESULT (ic))) == 1)
2845 OP_SYMBOL (IC_RESULT (ic))->remat = 1;
2846 OP_SYMBOL (IC_RESULT (ic))->rematiCode = ic;
2847 OP_SYMBOL (IC_RESULT (ic))->usl.spillLoc = NULL;
2850 /* mark the pointer usages */
2851 if (POINTER_SET (ic))
2852 OP_SYMBOL (IC_RESULT (ic))->uptr = 1;
2854 if (POINTER_GET (ic) &&
2855 IS_SYMOP(IC_LEFT (ic)))
2856 OP_SYMBOL (IC_LEFT (ic))->uptr = 1;
2860 /* if we are using a symbol on the stack
2861 then we should say mcs51_ptrRegReq */
2862 if (options.useXstack && ic->parmPush
2863 && (ic->op == IPUSH || ic->op == IPOP))
2865 if (ic->op == IFX && IS_SYMOP (IC_COND (ic)))
2866 mcs51_ptrRegReq += ((OP_SYMBOL (IC_COND (ic))->onStack ||
2867 OP_SYMBOL (IC_COND (ic))->iaccess ||
2868 SPEC_OCLS(OP_SYMBOL (IC_COND (ic))->etype) == idata) ? 1 : 0);
2869 else if (ic->op == JUMPTABLE && IS_SYMOP (IC_JTCOND (ic)))
2870 mcs51_ptrRegReq += ((OP_SYMBOL (IC_JTCOND (ic))->onStack ||
2871 OP_SYMBOL (IC_JTCOND (ic))->iaccess ||
2872 SPEC_OCLS(OP_SYMBOL (IC_JTCOND (ic))->etype) == idata) ? 1 : 0);
2875 if (IS_SYMOP (IC_LEFT (ic)))
2876 mcs51_ptrRegReq += ((OP_SYMBOL (IC_LEFT (ic))->onStack ||
2877 OP_SYMBOL (IC_LEFT (ic))->iaccess ||
2878 SPEC_OCLS(OP_SYMBOL (IC_LEFT (ic))->etype) == idata) ? 1 : 0);
2879 if (IS_SYMOP (IC_RIGHT (ic)))
2880 mcs51_ptrRegReq += ((OP_SYMBOL (IC_RIGHT (ic))->onStack ||
2881 OP_SYMBOL (IC_RIGHT (ic))->iaccess ||
2882 SPEC_OCLS(OP_SYMBOL (IC_RIGHT (ic))->etype) == idata) ? 1 : 0);
2883 if (IS_SYMOP (IC_RESULT (ic)))
2884 mcs51_ptrRegReq += ((OP_SYMBOL (IC_RESULT (ic))->onStack ||
2885 OP_SYMBOL (IC_RESULT (ic))->iaccess ||
2886 SPEC_OCLS(OP_SYMBOL (IC_RESULT (ic))->etype) == idata) ? 1 : 0);
2887 if (POINTER_GET (ic) && IS_SYMOP (IC_LEFT (ic))
2888 && getSize (OP_SYMBOL (IC_LEFT (ic))->type) <= (unsigned int) PTRSIZE)
2890 if (POINTER_SET (ic) && IS_SYMOP (IC_RESULT (ic))
2891 && getSize (OP_SYMBOL (IC_RESULT (ic))->type) <= (unsigned int) PTRSIZE)
2896 /* if the condition of an if instruction
2897 is defined in the previous instruction and
2898 this is the only usage then
2899 mark the itemp as a conditional */
2900 if ((IS_CONDITIONAL (ic) ||
2901 (IS_BITWISE_OP(ic) && isBitwiseOptimizable (ic))) &&
2902 ic->next && ic->next->op == IFX &&
2903 bitVectnBitsOn (OP_USES(IC_RESULT(ic)))==1 &&
2904 isOperandEqual (IC_RESULT (ic), IC_COND (ic->next)) &&
2905 OP_SYMBOL (IC_RESULT (ic))->liveTo <= ic->next->seq)
2907 OP_SYMBOL (IC_RESULT (ic))->regType = REG_CND;
2911 /* reduce for support function calls */
2912 if (ic->supportRtn || ic->op == '+' || ic->op == '-')
2913 packRegsForSupport (ic, ebp);
2915 /* some cases the redundant moves can
2916 can be eliminated for return statements */
2917 if ((ic->op == RETURN || (ic->op == SEND && ic->argreg == 1)) &&
2918 !isOperandInFarSpace (IC_LEFT (ic)) &&
2919 options.model == MODEL_SMALL) {
2920 packRegsForOneuse (ic, IC_LEFT (ic), ebp);
2923 /* if pointer set & left has a size more than
2924 one and right is not in far space */
2925 if (POINTER_SET (ic) &&
2926 !isOperandInFarSpace (IC_RIGHT (ic)) &&
2927 !OP_SYMBOL (IC_RESULT (ic))->remat &&
2928 !IS_OP_RUONLY (IC_RIGHT (ic)) &&
2929 getSize (aggrToPtr (operandType (IC_RESULT (ic)), FALSE)) > 1)
2930 packRegsForOneuse (ic, IC_RESULT (ic), ebp);
2932 /* if pointer get */
2933 if (POINTER_GET (ic) &&
2934 IS_SYMOP (IC_LEFT (ic)) &&
2935 !isOperandInFarSpace (IC_RESULT (ic)) &&
2936 !OP_SYMBOL (IC_LEFT (ic))->remat &&
2937 !IS_OP_RUONLY (IC_RESULT (ic)) &&
2938 getSize (aggrToPtr (operandType (IC_LEFT (ic)), FALSE)) > 1)
2939 packRegsForOneuse (ic, IC_LEFT (ic), ebp);
2942 /* if this is cast for intergral promotion then
2943 check if only use of the definition of the
2944 operand being casted/ if yes then replace
2945 the result of that arithmetic operation with
2946 this result and get rid of the cast */
2949 sym_link *fromType = operandType (IC_RIGHT (ic));
2950 sym_link *toType = operandType (IC_LEFT (ic));
2952 if (IS_INTEGRAL (fromType) && IS_INTEGRAL (toType) &&
2953 getSize (fromType) != getSize (toType) &&
2954 SPEC_USIGN (fromType) == SPEC_USIGN (toType))
2957 iCode *dic = packRegsForOneuse (ic, IC_RIGHT (ic), ebp);
2960 if (IS_ARITHMETIC_OP (dic))
2962 bitVectUnSetBit(OP_SYMBOL(IC_RESULT(dic))->defs,dic->key);
2963 ReplaceOpWithCheaperOp(&IC_RESULT (dic), IC_RESULT (ic));
2964 remiCodeFromeBBlock (ebp, ic);
2965 bitVectUnSetBit(OP_SYMBOL(IC_RESULT(ic))->defs,ic->key);
2966 hTabDeleteItem (&iCodehTab, ic->key, ic, DELETE_ITEM, NULL);
2967 OP_DEFS(IC_RESULT (dic))=bitVectSetBit (OP_DEFS (IC_RESULT (dic)), dic->key);
2971 OP_SYMBOL (IC_RIGHT (ic))->ruonly = 0;
2977 /* if the type from and type to are the same
2978 then if this is the only use then packit */
2979 if (compareType (operandType (IC_RIGHT (ic)),
2980 operandType (IC_LEFT (ic))) == 1)
2982 iCode *dic = packRegsForOneuse (ic, IC_RIGHT (ic), ebp);
2985 bitVectUnSetBit(OP_SYMBOL(IC_RESULT(dic))->defs,dic->key);
2986 ReplaceOpWithCheaperOp(&IC_RESULT (dic), IC_RESULT (ic));
2987 remiCodeFromeBBlock (ebp, ic);
2988 bitVectUnSetBit(OP_SYMBOL(IC_RESULT(ic))->defs,ic->key);
2989 hTabDeleteItem (&iCodehTab, ic->key, ic, DELETE_ITEM, NULL);
2990 OP_DEFS(IC_RESULT (dic))=bitVectSetBit (OP_DEFS (IC_RESULT (dic)), dic->key);
2998 iTempNN := (some variable in farspace) V1
3003 if (ic->op == IPUSH)
3005 packForPush (ic, ebpp, blockno);
3009 /* pack registers for accumulator use, when the
3010 result of an arithmetic or bit wise operation
3011 has only one use, that use is immediately following
3012 the defintion and the using iCode has only one
3013 operand or has two operands but one is literal &
3014 the result of that operation is not on stack then
3015 we can leave the result of this operation in acc:b
3017 if ((IS_ARITHMETIC_OP (ic)
3018 || IS_CONDITIONAL(ic)
3019 || IS_BITWISE_OP (ic)
3020 || ic->op == LEFT_OP || ic->op == RIGHT_OP || ic->op == CALL
3021 || (ic->op == ADDRESS_OF && isOperandOnStack (IC_LEFT (ic)))
3023 IS_ITEMP (IC_RESULT (ic)) &&
3024 getSize (operandType (IC_RESULT (ic))) <= 2)
3026 packRegsForAccUse (ic);
3030 /*-----------------------------------------------------------------*/
3031 /* assignRegisters - assigns registers to each live range as need */
3032 /*-----------------------------------------------------------------*/
3034 mcs51_assignRegisters (eBBlock ** ebbs, int count)
3039 setToNull ((void *) &_G.funcrUsed);
3040 setToNull ((void *) &_G.regAssigned);
3041 setToNull ((void *) &_G.totRegAssigned);
3042 mcs51_ptrRegReq = _G.stackExtend = _G.dataExtend = 0;
3045 /* change assignments this will remove some
3046 live ranges reducing some register pressure */
3048 for (i = 0; i < count; i++)
3049 packRegisters (ebbs, i);
3051 /* liveranges probably changed by register packing
3052 so we compute them again */
3053 recomputeLiveRanges (ebbs, count);
3055 if (options.dump_pack)
3056 dumpEbbsToFileExt (DUMP_PACK, ebbs, count);
3058 /* first determine for each live range the number of
3059 registers & the type of registers required for each */
3062 /* and serially allocate registers */
3063 serialRegAssign (ebbs, count);
3066 //setToNull ((void *) &_G.regAssigned);
3067 //setToNull ((void *) &_G.totRegAssigned);
3070 /* if stack was extended then tell the user */
3073 /* werror(W_TOOMANY_SPILS,"stack", */
3074 /* _G.stackExtend,currFunc->name,""); */
3080 /* werror(W_TOOMANY_SPILS,"data space", */
3081 /* _G.dataExtend,currFunc->name,""); */
3085 /* after that create the register mask
3086 for each of the instruction */
3087 createRegMask (ebbs, count);
3089 /* redo that offsets for stacked automatic variables */
3091 redoStackOffsets ();
3094 /* make sure r0 & r1 are flagged as used if they might be used */
3096 if (currFunc && mcs51_ptrRegReq)
3098 currFunc->regsUsed = bitVectSetBit (currFunc->regsUsed, R0_IDX);
3099 currFunc->regsUsed = bitVectSetBit (currFunc->regsUsed, R1_IDX);
3102 if (options.dump_rassgn)
3104 dumpEbbsToFileExt (DUMP_RASSGN, ebbs, count);
3105 dumpLiveRanges (DUMP_LRANGE, liveRanges);
3108 /* do the overlaysegment stuff SDCCmem.c */
3109 doOverlays (ebbs, count);
3111 /* now get back the chain */
3112 ic = iCodeLabelOptimize (iCodeFromeBBlock (ebbs, count));
3116 /* free up any _G.stackSpil locations allocated */
3117 applyToSet (_G.stackSpil, deallocStackSpil);
3119 setToNull ((void *) &_G.stackSpil);
3120 setToNull ((void *) &_G.spiltSet);
3121 /* mark all registers as free */