1 /** @name Z80 Register allocation functions.
4 Note: much of this is ripped straight from Sandeep's mcs51 code.
6 This code maps the virtual symbols and code onto the real
7 hardware. It allocates based on usage and how long the varible
8 lives into registers or temporary memory on the stack.
10 On the Z80 hl and ix and a are reserved for the code generator,
11 leaving bc and de for allocation. iy is unusable due to currently
12 as it's only adressable as a pair. The extra register pressure
13 from reserving hl is made up for by how much easier the sub
14 operations become. You could swap hl for iy if the undocumented
15 iyl/iyh instructions are available.
17 The stack frame is the common ix-bp style. Basically:
22 ix+0: calling functions ix
25 sp: end of local varibles
27 There is currently no support for bit spaces or banked functions.
29 This program is free software; you can redistribute it and/or
30 modify it under the terms of the GNU General Public License as
31 published by the Free Software Foundation; either version 2, or (at
32 your option) any later version. This program is distributed in the
33 hope that it will be useful, but WITHOUT ANY WARRANTY; without even
34 the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR
35 PURPOSE. See the GNU General Public License for more details.
37 You should have received a copy of the GNU General Public License
38 along with this program; if not, write to the Free Software
39 Foundation, 59 Temple Place - Suite 330, Boston, MA 02111-1307,
40 USA. In other words, you are welcome to use, share and improve
41 this program. You are forbidden to forbid anyone else to use,
42 share and improve what you give them. Help stamp out
47 #include "SDCCicode.h"
49 /* Flags to turn off optimisations.
54 DISABLE_PACK_ASSIGN = 0,
55 DISABLE_PACK_ONE_USE = 0,
60 /* Flags to turn on debugging code.
67 D_ACCUSE2_VERBOSE = 0,
77 #define D(_a, _s) if (_a) { printf _s; fflush(stdout); }
82 #define DISABLE_PACKREGSFORSUPPORT 1
83 #define DISABLE_PACKREGSFORACCUSE 1
85 extern void genZ80Code (iCode *);
87 /** Local static variables */
93 bitVect *totRegAssigned; /* final set of LRs that got into registers */
96 /* registers used in a function */
103 static regs _gbz80_regs[] =
105 {REG_GPR, C_IDX, "c", 1},
106 {REG_GPR, B_IDX, "b", 1},
107 {REG_CND, CND_IDX, "c", 1}
110 static regs _z80_regs[] =
112 {REG_GPR, C_IDX, "c", 1},
113 {REG_GPR, B_IDX, "b", 1},
114 {REG_GPR, E_IDX, "e", 1},
115 {REG_GPR, D_IDX, "d", 1},
116 {REG_CND, CND_IDX, "c", 1}
121 /** Number of usable registers (all but C) */
122 #define Z80_MAX_REGS ((sizeof(_z80_regs)/sizeof(_z80_regs[0]))-1)
123 #define GBZ80_MAX_REGS ((sizeof(_gbz80_regs)/sizeof(_gbz80_regs[0]))-1)
125 static void spillThis (symbol *);
126 static void freeAllRegs ();
128 /** Allocates register of given type.
129 'type' is not used on the z80 version. It was used to select
130 between pointer and general purpose registers on the mcs51 version.
132 @return Pointer to the newly allocated register.
135 allocReg (short type)
139 for (i = 0; i < _G.nRegs; i++)
141 /* For now we allocate from any free */
142 if (regsZ80[i].isFree)
144 regsZ80[i].isFree = 0;
147 currFunc->regsUsed = bitVectSetBit (currFunc->regsUsed, i);
149 D (D_ALLOC, ("allocReg: alloced %p\n", ®sZ80[i]));
153 D (D_ALLOC, ("allocReg: No free.\n"));
157 /** Returns pointer to register wit index number
164 for (i = 0; i < _G.nRegs; i++)
166 if (regsZ80[i].rIdx == idx)
172 wassertl (0, "regWithIdx not found");
176 /** Frees a register.
181 wassert (!reg->isFree);
183 D (D_ALLOC, ("freeReg: freed %p\n", reg));
187 /** Returns number of free registers.
195 for (i = 0; i < _G.nRegs; i++)
197 /* For now only one reg type */
198 if (regsZ80[i].isFree)
206 /** Free registers with type.
209 nfreeRegsType (int type)
214 if ((nfr = nFreeRegs (type)) == 0)
216 return nFreeRegs (REG_GPR);
220 return nFreeRegs (type);
223 /*-----------------------------------------------------------------*/
224 /* useReg - marks a register as used */
225 /*-----------------------------------------------------------------*/
232 /*-----------------------------------------------------------------*/
233 /* computeSpillable - given a point find the spillable live ranges */
234 /*-----------------------------------------------------------------*/
236 computeSpillable (iCode * ic)
240 /* spillable live ranges are those that are live at this
241 point . the following categories need to be subtracted
243 a) - those that are already spilt
244 b) - if being used by this one
245 c) - defined by this one */
247 spillable = bitVectCopy (ic->rlive);
249 bitVectCplAnd (spillable, _G.spiltSet); /* those already spilt */
251 bitVectCplAnd (spillable, ic->uses); /* used in this one */
252 bitVectUnSetBit (spillable, ic->defKey);
253 spillable = bitVectIntersect (spillable, _G.regAssigned);
258 /*-----------------------------------------------------------------*/
259 /* noSpilLoc - return true if a variable has no spil location */
260 /*-----------------------------------------------------------------*/
262 noSpilLoc (symbol * sym, eBBlock * ebp, iCode * ic)
264 return (sym->usl.spillLoc ? 0 : 1);
267 /*-----------------------------------------------------------------*/
268 /* hasSpilLoc - will return 1 if the symbol has spil location */
269 /*-----------------------------------------------------------------*/
271 hasSpilLoc (symbol * sym, eBBlock * ebp, iCode * ic)
273 return (sym->usl.spillLoc ? 1 : 0);
276 /** Will return 1 if the remat flag is set.
277 A symbol is rematerialisable if it doesnt need to be allocated
278 into registers at creation as it can be re-created at any time -
279 i.e. it's constant in some way.
282 rematable (symbol * sym, eBBlock * ebp, iCode * ic)
287 /*-----------------------------------------------------------------*/
288 /* allLRs - return true for all */
289 /*-----------------------------------------------------------------*/
291 allLRs (symbol * sym, eBBlock * ebp, iCode * ic)
296 /** liveRangesWith - applies function to a given set of live range
299 liveRangesWith (bitVect * lrs, int (func) (symbol *, eBBlock *, iCode *),
300 eBBlock * ebp, iCode * ic)
305 if (!lrs || !lrs->size)
308 for (i = 1; i < lrs->size; i++)
311 if (!bitVectBitValue (lrs, i))
314 /* if we don't find it in the live range
315 hash table we are in serious trouble */
316 if (!(sym = hTabItemWithKey (liveRanges, i)))
318 wassertl (0, "liveRangesWith could not find liveRange");
322 if (func (sym, ebp, ic) && bitVectBitValue (_G.regAssigned, sym->key))
324 addSetHead (&rset, sym);
332 /** leastUsedLR - given a set determines which is the least used
335 leastUsedLR (set * sset)
337 symbol *sym = NULL, *lsym = NULL;
339 sym = lsym = setFirstItem (sset);
344 for (; lsym; lsym = setNextItem (sset))
347 /* if usage is the same then prefer
348 the spill the smaller of the two */
349 if (lsym->used == sym->used)
350 if (getSize (lsym->type) < getSize (sym->type))
354 if (lsym->used < sym->used)
359 setToNull ((void **) &sset);
364 /** noOverLap - will iterate through the list looking for over lap
367 noOverLap (set * itmpStack, symbol * fsym)
371 for (sym = setFirstItem (itmpStack); sym;
372 sym = setNextItem (itmpStack))
374 if (bitVectBitValue(sym->clashes,fsym->key))
377 // if sym starts before (or on) our end point
378 // and ends after (or on) our start point,
380 if (sym->liveFrom <= fsym->liveTo &&
381 sym->liveTo >= fsym->liveFrom)
390 /*-----------------------------------------------------------------*/
391 /* isFree - will return 1 if the a free spil location is found */
392 /*-----------------------------------------------------------------*/
396 V_ARG (symbol **, sloc);
397 V_ARG (symbol *, fsym);
399 /* if already found */
403 /* if it is free && and the itmp assigned to
404 this does not have any overlapping live ranges
405 with the one currently being assigned and
406 the size can be accomodated */
408 noOverLap (sym->usl.itmpStack, fsym) &&
409 getSize (sym->type) >= getSize (fsym->type))
418 /*-----------------------------------------------------------------*/
419 /* createStackSpil - create a location on the stack to spil */
420 /*-----------------------------------------------------------------*/
422 createStackSpil (symbol * sym)
426 D (D_ALLOC, ("createStackSpil: for sym %p\n", sym));
428 /* first go try and find a free one that is already
429 existing on the stack */
430 if (applyToSet (_G.stackSpil, isFree, &sloc, sym))
432 /* found a free one : just update & return */
433 sym->usl.spillLoc = sloc;
436 addSetHead (&sloc->usl.itmpStack, sym);
437 D (D_ALLOC, ("createStackSpil: found existing\n"));
441 /* could not then have to create one , this is the hard part
442 we need to allocate this on the stack : this is really a
443 hack!! but cannot think of anything better at this time */
445 sprintf (buffer, "sloc%d", _G.slocNum++);
446 sloc = newiTemp (buffer);
448 /* set the type to the spilling symbol */
449 sloc->type = copyLinkChain (sym->type);
450 sloc->etype = getSpec (sloc->type);
451 SPEC_SCLS (sloc->etype) = S_AUTO;
452 SPEC_EXTR (sloc->etype) = 0;
453 SPEC_STAT (sloc->etype) = 0;
454 SPEC_VOLATILE(sloc->etype) = 0;
458 sloc->isref = 1; /* to prevent compiler warning */
460 /* if it is on the stack then update the stack */
461 if (IN_STACK (sloc->etype))
463 currFunc->stack += getSize (sloc->type);
464 _G.stackExtend += getSize (sloc->type);
468 _G.dataExtend += getSize (sloc->type);
471 /* add it to the stackSpil set */
472 addSetHead (&_G.stackSpil, sloc);
473 sym->usl.spillLoc = sloc;
476 /* add it to the set of itempStack set
477 of the spill location */
478 addSetHead (&sloc->usl.itmpStack, sym);
480 D (D_ALLOC, ("createStackSpil: created new\n"));
484 /*-----------------------------------------------------------------*/
485 /* spillThis - spils a specific operand */
486 /*-----------------------------------------------------------------*/
488 spillThis (symbol * sym)
492 D (D_ALLOC, ("spillThis: spilling %p\n", sym));
494 /* if this is rematerializable or has a spillLocation
495 we are okay, else we need to create a spillLocation
497 if (!(sym->remat || sym->usl.spillLoc))
499 createStackSpil (sym);
502 /* mark it has spilt & put it in the spilt set */
503 sym->isspilt = sym->spillA = 1;
504 _G.spiltSet = bitVectSetBit (_G.spiltSet, sym->key);
506 bitVectUnSetBit (_G.regAssigned, sym->key);
507 bitVectUnSetBit (_G.totRegAssigned, sym->key);
509 for (i = 0; i < sym->nRegs; i++)
513 freeReg (sym->regs[i]);
518 if (sym->usl.spillLoc && !sym->remat)
520 sym->usl.spillLoc->allocreq++;
526 /*-----------------------------------------------------------------*/
527 /* allDefsOutOfRange - all definitions are out of a range */
528 /*-----------------------------------------------------------------*/
530 allDefsOutOfRange (bitVect * defs, int fseq, int toseq)
537 for (i = 0; i < defs->size; i++)
541 if (bitVectBitValue (defs, i) &&
542 (ic = hTabItemWithKey (iCodehTab, i)) &&
543 (ic->seq >= fseq && ic->seq <= toseq))
552 /*-----------------------------------------------------------------*/
553 /* hasSpilLocnoUptr - will return 1 if the symbol has spil location */
554 /* but is not used as a pointer */
555 /*-----------------------------------------------------------------*/
557 hasSpilLocnoUptr (symbol * sym, eBBlock * ebp, iCode * ic)
559 return ((sym->usl.spillLoc && !sym->uptr) ? 1 : 0);
562 /*-----------------------------------------------------------------*/
563 /* notUsedInRemaining - not used or defined in remain of the block */
564 /*-----------------------------------------------------------------*/
566 notUsedInRemaining (symbol * sym, eBBlock * ebp, iCode * ic)
568 return ((usedInRemaining (operandFromSymbol (sym), ic) ? 0 : 1) &&
569 allDefsOutOfRange (sym->defs, ebp->fSeq, ebp->lSeq));
573 /** Select a iTemp to spil : rather a simple procedure.
576 selectSpil (iCode * ic, eBBlock * ebp, symbol * forSym)
578 bitVect *lrcs = NULL;
582 D (D_ALLOC, ("selectSpil: finding spill for ic %p\n", ic));
583 /* get the spillable live ranges */
584 lrcs = computeSpillable (ic);
586 /* get all live ranges that are rematerizable */
587 if ((selectS = liveRangesWith (lrcs, rematable, ebp, ic)))
589 D (D_ALLOC, ("selectSpil: using remat.\n"));
590 /* return the least used of these */
591 return leastUsedLR (selectS);
595 /* get live ranges with spillLocations in direct space */
596 if ((selectS = liveRangesWith (lrcs, directSpilLoc, ebp, ic)))
598 sym = leastUsedLR (selectS);
599 strcpy (sym->rname, (sym->usl.spillLoc->rname[0] ?
600 sym->usl.spillLoc->rname :
601 sym->usl.spillLoc->name));
603 /* mark it as allocation required */
604 sym->usl.spillLoc->allocreq++;
608 /* if the symbol is local to the block then */
609 if (forSym->liveTo < ebp->lSeq)
612 /* check if there are any live ranges allocated
613 to registers that are not used in this block */
614 if (!_G.blockSpil && (selectS = liveRangesWith (lrcs, notUsedInBlock, ebp, ic)))
616 sym = leastUsedLR (selectS);
617 /* if this is not rematerializable */
621 wassertl (0, "Attempted to do an unsupported block spill");
627 /* check if there are any live ranges that not
628 used in the remainder of the block */
629 if (!_G.blockSpil && (selectS = liveRangesWith (lrcs, notUsedInRemaining, ebp, ic)))
631 sym = leastUsedLR (selectS);
636 wassertl (0, "Attempted to do an unsupported remain spill");
644 /* find live ranges with spillocation && not used as pointers */
645 if ((selectS = liveRangesWith (lrcs, hasSpilLocnoUptr, ebp, ic)))
648 sym = leastUsedLR (selectS);
649 /* mark this as allocation required */
650 sym->usl.spillLoc->allocreq++;
655 /* find live ranges with spillocation */
656 if ((selectS = liveRangesWith (lrcs, hasSpilLoc, ebp, ic)))
658 D (D_ALLOC, ("selectSpil: using with spill.\n"));
659 sym = leastUsedLR (selectS);
660 sym->usl.spillLoc->allocreq++;
664 /* couldn't find then we need to create a spil
665 location on the stack , for which one? the least
667 if ((selectS = liveRangesWith (lrcs, noSpilLoc, ebp, ic)))
669 D (D_ALLOC, ("selectSpil: creating new spill.\n"));
670 /* return a created spil location */
671 sym = createStackSpil (leastUsedLR (selectS));
672 sym->usl.spillLoc->allocreq++;
676 /* this is an extreme situation we will spill
677 this one : happens very rarely but it does happen */
678 D (D_ALLOC, ("selectSpil: using spillThis.\n"));
684 /** Spil some variable & mark registers as free.
685 A spill occurs when an iTemp wont fit into the available registers.
688 spilSomething (iCode * ic, eBBlock * ebp, symbol * forSym)
693 D (D_ALLOC, ("spilSomething: spilling on ic %p\n", ic));
695 /* get something we can spil */
696 ssym = selectSpil (ic, ebp, forSym);
698 /* mark it as spilt */
699 ssym->isspilt = ssym->spillA = 1;
700 _G.spiltSet = bitVectSetBit (_G.spiltSet, ssym->key);
702 /* mark it as not register assigned &
703 take it away from the set */
704 bitVectUnSetBit (_G.regAssigned, ssym->key);
705 bitVectUnSetBit (_G.totRegAssigned, ssym->key);
707 /* mark the registers as free */
708 for (i = 0; i < ssym->nRegs; i++)
710 freeReg (ssym->regs[i]);
712 wassertl (ssym->blockSpil == 0, "Encountered a sym with a block spill");
713 wassertl (ssym->remainSpil == 0, "Encountered a sym with a remain spill");
715 /* if spilt on stack then free up r0 & r1
716 if they could have been assigned to as gprs */
717 if (!ptrRegReq && isSpiltOnStack (ssym))
720 spillLRWithPtrReg (ssym);
723 /* if this was a block level spil then insert push & pop
724 at the start & end of block respectively */
727 iCode *nic = newiCode (IPUSH, operandFromSymbol (ssym), NULL);
728 /* add push to the start of the block */
729 addiCodeToeBBlock (ebp, nic, (ebp->sch->op == LABEL ?
730 ebp->sch->next : ebp->sch));
731 nic = newiCode (IPOP, operandFromSymbol (ssym), NULL);
732 /* add pop to the end of the block */
733 addiCodeToeBBlock (ebp, nic, NULL);
736 /* if spilt because not used in the remainder of the
737 block then add a push before this instruction and
738 a pop at the end of the block */
739 if (ssym->remainSpil)
742 iCode *nic = newiCode (IPUSH, operandFromSymbol (ssym), NULL);
743 /* add push just before this instruction */
744 addiCodeToeBBlock (ebp, nic, ic);
746 nic = newiCode (IPOP, operandFromSymbol (ssym), NULL);
747 /* add pop to the end of the block */
748 addiCodeToeBBlock (ebp, nic, NULL);
752 D (D_ALLOC, ("spilSomething: done.\n"));
760 /** Will try for GPR if not spil.
763 getRegGpr (iCode * ic, eBBlock * ebp, symbol * sym)
767 D (D_ALLOC, ("getRegGpr: on ic %p\n", ic));
769 /* try for gpr type */
770 if ((reg = allocReg (REG_GPR)))
772 D (D_ALLOC, ("getRegGpr: got a reg.\n"));
776 /* we have to spil */
777 if (!spilSomething (ic, ebp, sym))
779 D (D_ALLOC, ("getRegGpr: have to spill.\n"));
783 /* this looks like an infinite loop but
784 in really selectSpil will abort */
788 static regs *getRegGprNoSpil()
792 /* try for gpr type */
793 if ((reg = allocReg (REG_GPR)))
795 D (D_ALLOC, ("getRegGprNoSpil: got a reg.\n"));
801 /** Symbol has a given register.
804 symHasReg (symbol * sym, regs * reg)
808 for (i = 0; i < sym->nRegs; i++)
809 if (sym->regs[i] == reg)
815 /** Check the live to and if they have registers & are not spilt then
816 free up the registers
819 deassignLRs (iCode * ic, eBBlock * ebp)
825 for (sym = hTabFirstItem (liveRanges, &k); sym;
826 sym = hTabNextItem (liveRanges, &k))
830 /* if it does not end here */
831 if (sym->liveTo > ic->seq)
834 /* if it was spilt on stack then we can
835 mark the stack spil location as free */
840 sym->usl.spillLoc->isFree = 1;
846 if (!bitVectBitValue (_G.regAssigned, sym->key))
849 /* special case check if this is an IFX &
850 the privious one was a pop and the
851 previous one was not spilt then keep track
853 if (ic->op == IFX && ic->prev &&
854 ic->prev->op == IPOP &&
855 !ic->prev->parmPush &&
856 !OP_SYMBOL (IC_LEFT (ic->prev))->isspilt)
857 psym = OP_SYMBOL (IC_LEFT (ic->prev));
859 D (D_ALLOC, ("deassignLRs: in loop on sym %p nregs %u\n", sym, sym->nRegs));
865 bitVectUnSetBit (_G.regAssigned, sym->key);
867 /* if the result of this one needs registers
868 and does not have it then assign it right
870 if (IC_RESULT (ic) &&
871 !(SKIP_IC2 (ic) || /* not a special icode */
872 ic->op == JUMPTABLE ||
877 (result = OP_SYMBOL (IC_RESULT (ic))) && /* has a result */
878 result->liveTo > ic->seq && /* and will live beyond this */
879 result->liveTo <= ebp->lSeq && /* does not go beyond this block */
880 result->regType == sym->regType && /* same register types */
881 result->nRegs && /* which needs registers */
882 !result->isspilt && /* and does not already have them */
884 !bitVectBitValue (_G.regAssigned, result->key) &&
885 /* the number of free regs + number of regs in this LR
886 can accomodate the what result Needs */
887 ((nfreeRegsType (result->regType) +
888 sym->nRegs) >= result->nRegs)
891 for (i = 0; i < result->nRegs; i++)
894 result->regs[i] = sym->regs[i];
896 result->regs[i] = getRegGpr (ic, ebp, result);
898 /* if the allocation falied which means
899 this was spilt then break */
900 if (!result->regs[i])
908 _G.regAssigned = bitVectSetBit (_G.regAssigned, result->key);
909 _G.totRegAssigned = bitVectSetBit (_G.totRegAssigned, result->key);
912 /* free the remaining */
913 for (; i < sym->nRegs; i++)
917 if (!symHasReg (psym, sym->regs[i]))
918 freeReg (sym->regs[i]);
921 freeReg (sym->regs[i]);
922 // sym->regs[i] = NULL;
929 /** Reassign this to registers.
932 reassignLR (operand * op)
934 symbol *sym = OP_SYMBOL (op);
937 D (D_ALLOC, ("reassingLR: on sym %p\n", sym));
939 /* not spilt any more */
940 sym->isspilt = sym->spillA = sym->blockSpil = sym->remainSpil = 0;
941 bitVectUnSetBit (_G.spiltSet, sym->key);
943 _G.regAssigned = bitVectSetBit (_G.regAssigned, sym->key);
944 _G.totRegAssigned = bitVectSetBit (_G.totRegAssigned, sym->key);
948 for (i = 0; i < sym->nRegs; i++)
949 sym->regs[i]->isFree = 0;
952 /** Determines if allocating will cause a spill.
955 willCauseSpill (int nr, int rt)
957 /* first check if there are any avlb registers
958 of te type required */
959 if (nFreeRegs (0) >= nr)
962 /* it will cause a spil */
966 /** The allocator can allocate same registers to result and operand,
967 if this happens make sure they are in the same position as the operand
968 otherwise chaos results.
971 positionRegs (symbol * result, symbol * opsym)
973 int count = min (result->nRegs, opsym->nRegs);
974 int i, j = 0, shared = 0;
977 D (D_ALLOC, ("positionRegs: on result %p opsum %p line %u\n", result, opsym, lineno));
979 /* if the result has been spilt then cannot share */
984 /* first make sure that they actually share */
985 for (i = 0; i < count; i++)
987 for (j = 0; j < count; j++)
989 if (result->regs[i] == opsym->regs[j] && i != j)
999 regs *tmp = result->regs[i];
1000 result->regs[i] = result->regs[j];
1001 result->regs[j] = tmp;
1008 /** Try to allocate a pair of registers to the symbol.
1011 tryAllocatingRegPair (symbol * sym)
1014 wassert (sym->nRegs == 2);
1015 for (i = 0; i < _G.nRegs; i += 2)
1017 if ((regsZ80[i].isFree) && (regsZ80[i + 1].isFree))
1019 regsZ80[i].isFree = 0;
1020 sym->regs[0] = ®sZ80[i];
1021 regsZ80[i + 1].isFree = 0;
1022 sym->regs[1] = ®sZ80[i + 1];
1023 sym->regType = REG_PAIR;
1027 currFunc->regsUsed =
1028 bitVectSetBit (currFunc->regsUsed, i);
1029 currFunc->regsUsed =
1030 bitVectSetBit (currFunc->regsUsed, i + 1);
1032 D (D_ALLOC, ("tryAllocRegPair: succeded for sym %p\n", sym));
1036 D (D_ALLOC, ("tryAllocRegPair: failed on sym %p\n", sym));
1040 /** Serially allocate registers to the variables.
1041 This is the main register allocation function. It is called after
1045 serialRegAssign (eBBlock ** ebbs, int count)
1049 /* for all blocks */
1050 for (i = 0; i < count; i++)
1055 if (ebbs[i]->noPath &&
1056 (ebbs[i]->entryLabel != entryLabel &&
1057 ebbs[i]->entryLabel != returnLabel))
1060 /* of all instructions do */
1061 for (ic = ebbs[i]->sch; ic; ic = ic->next)
1064 /* if this is an ipop that means some live
1065 range will have to be assigned again */
1069 reassignLR (IC_LEFT (ic));
1072 /* if result is present && is a true symbol */
1073 if (IC_RESULT (ic) && ic->op != IFX &&
1074 IS_TRUE_SYMOP (IC_RESULT (ic)))
1075 OP_SYMBOL (IC_RESULT (ic))->allocreq++;
1077 /* take away registers from live
1078 ranges that end at this instruction */
1079 deassignLRs (ic, ebbs[i]);
1081 /* some don't need registers */
1082 /* MLH: removed RESULT and POINTER_SET condition */
1083 if (SKIP_IC2 (ic) ||
1084 ic->op == JUMPTABLE ||
1090 /* now we need to allocate registers only for the result */
1093 symbol *sym = OP_SYMBOL (IC_RESULT (ic));
1098 D (D_ALLOC, ("serialRegAssign: in loop on result %p\n", sym));
1100 /* if it does not need or is spilt
1101 or is already assigned to registers
1102 or will not live beyond this instructions */
1105 bitVectBitValue (_G.regAssigned, sym->key) ||
1106 sym->liveTo <= ic->seq)
1108 D (D_ALLOC, ("serialRegAssign: wont live long enough.\n"));
1112 /* if some liverange has been spilt at the block level
1113 and this one live beyond this block then spil this
1115 if (_G.blockSpil && sym->liveTo > ebbs[i]->lSeq)
1117 D (D_ALLOC, ("serialRegAssign: \"spilling to be safe.\"\n"));
1121 /* if trying to allocate this will cause
1122 a spill and there is nothing to spill
1123 or this one is rematerializable then
1125 willCS = willCauseSpill (sym->nRegs, sym->regType);
1126 spillable = computeSpillable (ic);
1128 (willCS && bitVectIsZero (spillable)))
1131 D (D_ALLOC, ("serialRegAssign: \"remat spill\"\n"));
1137 /* if it has a spillocation & is used less than
1138 all other live ranges then spill this */
1140 if (sym->usl.spillLoc) {
1141 symbol *leastUsed = leastUsedLR (liveRangesWith (spillable,
1142 allLRs, ebbs[i], ic));
1143 if (leastUsed && leastUsed->used > sym->used) {
1148 /* if none of the liveRanges have a spillLocation then better
1149 to spill this one than anything else already assigned to registers */
1150 if (liveRangesWith(spillable,noSpilLoc,ebbs[i],ic)) {
1151 /* if this is local to this block then we might find a block spil */
1152 if (!(sym->liveFrom >= ebbs[i]->fSeq && sym->liveTo <= ebbs[i]->lSeq)) {
1160 /* else we assign registers to it */
1161 _G.regAssigned = bitVectSetBit (_G.regAssigned, sym->key);
1162 _G.totRegAssigned = bitVectSetBit (_G.totRegAssigned, sym->key);
1164 /* Special case: Try to fit into a reg pair if
1166 D (D_ALLOC, ("serialRegAssign: actually allocing regs!\n"));
1167 if ((sym->nRegs == 2) && tryAllocatingRegPair (sym))
1172 for (j = 0; j < sym->nRegs; j++)
1174 sym->regs[j] = getRegGpr (ic, ebbs[i], sym);
1176 /* if the allocation falied which means
1177 this was spilt then break */
1180 D (D_ALLOC, ("Couldnt alloc (spill)\n"))
1185 /* if it shares registers with operands make sure
1186 that they are in the same position */
1187 if (IC_LEFT (ic) && IS_SYMOP (IC_LEFT (ic)) &&
1188 OP_SYMBOL (IC_LEFT (ic))->nRegs && ic->op != '=')
1189 positionRegs (OP_SYMBOL (IC_RESULT (ic)),
1190 OP_SYMBOL (IC_LEFT (ic)));
1191 /* do the same for the right operand */
1192 if (IC_RIGHT (ic) && IS_SYMOP (IC_RIGHT (ic)) &&
1193 OP_SYMBOL (IC_RIGHT (ic))->nRegs)
1194 positionRegs (OP_SYMBOL (IC_RESULT (ic)),
1195 OP_SYMBOL (IC_RIGHT (ic)));
1202 /*-----------------------------------------------------------------*/
1203 /* fillGaps - Try to fill in the Gaps left by Pass1 */
1204 /*-----------------------------------------------------------------*/
1205 static void fillGaps()
1210 if (getenv("DISABLE_FILL_GAPS")) return;
1212 /* look for livernages that was spilt by the allocator */
1213 for (sym = hTabFirstItem(liveRanges,&key) ; sym ;
1214 sym = hTabNextItem(liveRanges,&key)) {
1219 if (!sym->spillA || !sym->clashes || sym->remat) continue ;
1221 /* find the liveRanges this one clashes with, that are
1222 still assigned to registers & mark the registers as used*/
1223 for ( i = 0 ; i < sym->clashes->size ; i ++) {
1227 if (bitVectBitValue(sym->clashes,i) == 0 || /* those that clash with this */
1228 bitVectBitValue(_G.totRegAssigned,i) == 0) /* and are still assigned to registers */
1231 assert (clr = hTabItemWithKey(liveRanges,i));
1233 /* mark these registers as used */
1234 for (k = 0 ; k < clr->nRegs ; k++ )
1235 useReg(clr->regs[k]);
1238 if (willCauseSpill(sym->nRegs,sym->regType)) {
1239 /* NOPE :( clear all registers & and continue */
1244 /* THERE IS HOPE !!!! */
1245 for (i=0; i < sym->nRegs ; i++ ) {
1246 sym->regs[i] = getRegGprNoSpil ();
1249 /* for all its definitions check if the registers
1250 allocated needs positioning NOTE: we can position
1251 only ONCE if more than One positioning required
1254 for (i = 0 ; i < sym->defs->size ; i++ ) {
1255 if (bitVectBitValue(sym->defs,i)) {
1257 if (!(ic = hTabItemWithKey(iCodehTab,i))) continue ;
1258 if (SKIP_IC(ic)) continue;
1259 assert(isSymbolEqual(sym,OP_SYMBOL(IC_RESULT(ic)))); /* just making sure */
1260 /* if left is assigned to registers */
1261 if (IS_SYMOP(IC_LEFT(ic)) &&
1262 bitVectBitValue(_G.totRegAssigned,OP_SYMBOL(IC_LEFT(ic))->key)) {
1263 pdone += positionRegs(sym,OP_SYMBOL(IC_LEFT(ic)));
1265 if (IS_SYMOP(IC_RIGHT(ic)) &&
1266 bitVectBitValue(_G.totRegAssigned,OP_SYMBOL(IC_RIGHT(ic))->key)) {
1267 pdone += positionRegs(sym,OP_SYMBOL(IC_RIGHT(ic)));
1269 if (pdone > 1) break;
1272 for (i = 0 ; i < sym->uses->size ; i++ ) {
1273 if (bitVectBitValue(sym->uses,i)) {
1275 if (!(ic = hTabItemWithKey(iCodehTab,i))) continue ;
1276 if (SKIP_IC(ic)) continue;
1277 if (!IS_ASSIGN_ICODE(ic)) continue ;
1279 /* if result is assigned to registers */
1280 if (IS_SYMOP(IC_RESULT(ic)) &&
1281 bitVectBitValue(_G.totRegAssigned,OP_SYMBOL(IC_RESULT(ic))->key)) {
1282 pdone += positionRegs(sym,OP_SYMBOL(IC_RESULT(ic)));
1284 if (pdone > 1) break;
1287 /* had to position more than once GIVE UP */
1289 /* UNDO all the changes we made to try this */
1291 for (i=0; i < sym->nRegs ; i++ ) {
1292 sym->regs[i] = NULL;
1295 D(D_FILL_GAPS,("Fill Gap gave up due to positioning for %s in function %s\n",sym->name, currFunc ? currFunc->name : "UNKNOWN"));
1298 D(D_FILL_GAPS,("FILLED GAP for %s in function %s\n",sym->name, currFunc ? currFunc->name : "UNKNOWN"));
1299 _G.totRegAssigned = bitVectSetBit(_G.totRegAssigned,sym->key);
1300 sym->isspilt = sym->spillA = 0 ;
1301 sym->usl.spillLoc->allocreq--;
1306 /*-----------------------------------------------------------------*/
1307 /* rUmaskForOp :- returns register mask for an operand */
1308 /*-----------------------------------------------------------------*/
1310 rUmaskForOp (operand * op)
1316 /* only temporaries are assigned registers */
1320 sym = OP_SYMBOL (op);
1322 /* if spilt or no registers assigned to it
1324 if (sym->isspilt || !sym->nRegs)
1327 rumask = newBitVect (_G.nRegs);
1329 for (j = 0; j < sym->nRegs; j++)
1331 rumask = bitVectSetBit (rumask, sym->regs[j]->rIdx);
1338 z80_rUmaskForOp (operand * op)
1340 return rUmaskForOp (op);
1343 /** Returns bit vector of registers used in iCode.
1346 regsUsedIniCode (iCode * ic)
1348 bitVect *rmask = newBitVect (_G.nRegs);
1350 /* do the special cases first */
1353 rmask = bitVectUnion (rmask,
1354 rUmaskForOp (IC_COND (ic)));
1358 /* for the jumptable */
1359 if (ic->op == JUMPTABLE)
1361 rmask = bitVectUnion (rmask,
1362 rUmaskForOp (IC_JTCOND (ic)));
1367 /* of all other cases */
1369 rmask = bitVectUnion (rmask,
1370 rUmaskForOp (IC_LEFT (ic)));
1374 rmask = bitVectUnion (rmask,
1375 rUmaskForOp (IC_RIGHT (ic)));
1378 rmask = bitVectUnion (rmask,
1379 rUmaskForOp (IC_RESULT (ic)));
1385 /** For each instruction will determine the regsUsed.
1388 createRegMask (eBBlock ** ebbs, int count)
1392 /* for all blocks */
1393 for (i = 0; i < count; i++)
1397 if (ebbs[i]->noPath &&
1398 (ebbs[i]->entryLabel != entryLabel &&
1399 ebbs[i]->entryLabel != returnLabel))
1402 /* for all instructions */
1403 for (ic = ebbs[i]->sch; ic; ic = ic->next)
1408 if (SKIP_IC2 (ic) || !ic->rlive)
1411 /* first mark the registers used in this
1413 ic->rUsed = regsUsedIniCode (ic);
1414 _G.funcrUsed = bitVectUnion (_G.funcrUsed, ic->rUsed);
1416 /* now create the register mask for those
1417 registers that are in use : this is a
1418 super set of ic->rUsed */
1419 ic->rMask = newBitVect (_G.nRegs + 1);
1421 /* for all live Ranges alive at this point */
1422 for (j = 1; j < ic->rlive->size; j++)
1427 /* if not alive then continue */
1428 if (!bitVectBitValue (ic->rlive, j))
1431 /* find the live range we are interested in */
1432 if (!(sym = hTabItemWithKey (liveRanges, j)))
1434 werror (E_INTERNAL_ERROR, __FILE__, __LINE__,
1435 "createRegMask cannot find live range");
1439 /* if no register assigned to it */
1440 if (!sym->nRegs || sym->isspilt)
1443 /* for all the registers allocated to it */
1444 for (k = 0; k < sym->nRegs; k++)
1447 bitVectSetBit (ic->rMask, sym->regs[k]->rIdx);
1453 /** Returns the rematerialized string for a remat var.
1456 rematStr (symbol * sym)
1459 iCode *ic = sym->rematiCode;
1464 /* if plus or minus print the right hand side */
1465 if (ic->op == '+' || ic->op == '-')
1467 sprintf (s, "0x%04x %c ", (int) operandLitValue (IC_RIGHT (ic)),
1470 ic = OP_SYMBOL (IC_LEFT (ic))->rematiCode;
1473 /* we reached the end */
1474 sprintf (s, "%s", OP_SYMBOL (IC_LEFT (ic))->rname);
1481 /*-----------------------------------------------------------------*/
1482 /* regTypeNum - computes the type & number of registers required */
1483 /*-----------------------------------------------------------------*/
1490 /* for each live range do */
1491 for (sym = hTabFirstItem (liveRanges, &k); sym;
1492 sym = hTabNextItem (liveRanges, &k))
1495 /* if used zero times then no registers needed */
1496 if ((sym->liveTo - sym->liveFrom) == 0)
1499 D (D_ALLOC, ("regTypeNum: loop on sym %p\n", sym));
1501 /* if the live range is a temporary */
1505 /* if the type is marked as a conditional */
1506 if (sym->regType == REG_CND)
1509 /* if used in return only then we don't
1511 if (sym->ruonly || sym->accuse)
1513 if (IS_AGGREGATE (sym->type) || sym->isptr)
1514 sym->type = aggrToPtr (sym->type, FALSE);
1518 /* if not then we require registers */
1519 D (D_ALLOC, ("regTypeNum: isagg %u nRegs %u type %p\n", IS_AGGREGATE (sym->type) || sym->isptr, sym->nRegs, sym->type));
1520 sym->nRegs = ((IS_AGGREGATE (sym->type) || sym->isptr) ?
1521 getSize (sym->type = aggrToPtr (sym->type, FALSE)) :
1522 getSize (sym->type));
1523 D (D_ALLOC, ("regTypeNum: setting nRegs of %s (%p) to %u\n", sym->name, sym, sym->nRegs));
1525 D (D_ALLOC, ("regTypeNum: setup to assign regs sym %p\n", sym));
1529 fprintf (stderr, "allocated more than 4 or 0 registers for type ");
1530 printTypeChain (sym->type, stderr);
1531 fprintf (stderr, "\n");
1534 /* determine the type of register required */
1535 /* Always general purpose */
1536 sym->regType = REG_GPR;
1541 /* for the first run we don't provide */
1542 /* registers for true symbols we will */
1543 /* see how things go */
1544 D (D_ALLOC, ("regTypeNum: #2 setting num of %p to 0\n", sym));
1551 /** Mark all registers as free.
1558 D (D_ALLOC, ("freeAllRegs: running.\n"));
1560 for (i = 0; i < _G.nRegs; i++)
1561 regsZ80[i].isFree = 1;
1564 /*-----------------------------------------------------------------*/
1565 /* deallocStackSpil - this will set the stack pointer back */
1566 /*-----------------------------------------------------------------*/
1567 DEFSETFUNC (deallocStackSpil)
1575 /** Register reduction for assignment.
1578 packRegsForAssign (iCode * ic, eBBlock * ebp)
1582 D (D_ALLOC, ("packRegsForAssign: running on ic %p\n", ic));
1584 if (!IS_ITEMP (IC_RIGHT (ic)) ||
1585 OP_SYMBOL (IC_RIGHT (ic))->isind ||
1586 OP_LIVETO (IC_RIGHT (ic)) > ic->seq)
1591 /* find the definition of iTempNN scanning backwards if we find a
1592 a use of the true symbol in before we find the definition then
1594 for (dic = ic->prev; dic; dic = dic->prev)
1596 /* PENDING: Don't pack across function calls. */
1597 if (dic->op == CALL || dic->op == PCALL)
1606 if (IS_SYMOP (IC_RESULT (dic)) &&
1607 IC_RESULT (dic)->key == IC_RIGHT (ic)->key)
1612 if (IS_SYMOP (IC_RIGHT (dic)) &&
1613 (IC_RIGHT (dic)->key == IC_RESULT (ic)->key ||
1614 IC_RIGHT (dic)->key == IC_RIGHT (ic)->key))
1620 if (IS_SYMOP (IC_LEFT (dic)) &&
1621 (IC_LEFT (dic)->key == IC_RESULT (ic)->key ||
1622 IC_LEFT (dic)->key == IC_RIGHT (ic)->key))
1630 return 0; /* did not find */
1632 /* if the result is on stack or iaccess then it must be
1633 the same atleast one of the operands */
1634 if (OP_SYMBOL (IC_RESULT (ic))->onStack ||
1635 OP_SYMBOL (IC_RESULT (ic))->iaccess)
1637 /* the operation has only one symbol
1638 operator then we can pack */
1639 if ((IC_LEFT (dic) && !IS_SYMOP (IC_LEFT (dic))) ||
1640 (IC_RIGHT (dic) && !IS_SYMOP (IC_RIGHT (dic))))
1643 if (!((IC_LEFT (dic) &&
1644 IC_RESULT (ic)->key == IC_LEFT (dic)->key) ||
1646 IC_RESULT (ic)->key == IC_RIGHT (dic)->key)))
1650 /* found the definition */
1651 /* replace the result with the result of */
1652 /* this assignment and remove this assignment */
1653 bitVectUnSetBit(OP_SYMBOL(IC_RESULT(dic))->defs,dic->key);
1654 IC_RESULT (dic) = IC_RESULT (ic);
1656 if (IS_ITEMP (IC_RESULT (dic)) && OP_SYMBOL (IC_RESULT (dic))->liveFrom > dic->seq)
1658 OP_SYMBOL (IC_RESULT (dic))->liveFrom = dic->seq;
1660 /* delete from liverange table also
1661 delete from all the points inbetween and the new
1663 for (sic = dic; sic != ic; sic = sic->next)
1665 bitVectUnSetBit (sic->rlive, IC_RESULT (ic)->key);
1666 if (IS_ITEMP (IC_RESULT (dic)))
1667 bitVectSetBit (sic->rlive, IC_RESULT (dic)->key);
1670 remiCodeFromeBBlock (ebp, ic);
1671 // PENDING: Check vs mcs51
1672 bitVectUnSetBit(OP_SYMBOL(IC_RESULT(ic))->defs,ic->key);
1673 hTabDeleteItem (&iCodehTab, ic->key, ic, DELETE_ITEM, NULL);
1674 OP_DEFS (IC_RESULT (dic)) = bitVectSetBit (OP_DEFS (IC_RESULT (dic)), dic->key);
1678 /** Scanning backwards looks for first assig found.
1681 findAssignToSym (operand * op, iCode * ic)
1685 for (dic = ic->prev; dic; dic = dic->prev)
1688 /* if definition by assignment */
1689 if (dic->op == '=' &&
1690 !POINTER_SET (dic) &&
1691 IC_RESULT (dic)->key == op->key)
1692 /* && IS_TRUE_SYMOP(IC_RIGHT(dic)) */
1695 /* we are interested only if defined in far space */
1696 /* or in stack space in case of + & - */
1698 /* if assigned to a non-symbol then return
1700 if (!IS_SYMOP (IC_RIGHT (dic)))
1703 /* if the symbol is in far space then
1705 if (isOperandInFarSpace (IC_RIGHT (dic)))
1708 /* for + & - operations make sure that
1709 if it is on the stack it is the same
1710 as one of the three operands */
1711 if ((ic->op == '+' || ic->op == '-') &&
1712 OP_SYMBOL (IC_RIGHT (dic))->onStack)
1715 if (IC_RESULT (ic)->key != IC_RIGHT (dic)->key &&
1716 IC_LEFT (ic)->key != IC_RIGHT (dic)->key &&
1717 IC_RIGHT (ic)->key != IC_RIGHT (dic)->key)
1725 /* if we find an usage then we cannot delete it */
1726 if (IC_LEFT (dic) && IC_LEFT (dic)->key == op->key)
1729 if (IC_RIGHT (dic) && IC_RIGHT (dic)->key == op->key)
1732 if (POINTER_SET (dic) && IC_RESULT (dic)->key == op->key)
1736 /* now make sure that the right side of dic
1737 is not defined between ic & dic */
1740 iCode *sic = dic->next;
1742 for (; sic != ic; sic = sic->next)
1743 if (IC_RESULT (sic) &&
1744 IC_RESULT (sic)->key == IC_RIGHT (dic)->key)
1753 #if !DISABLE_PACKREGSFORSUPPORT
1756 /*-----------------------------------------------------------------*/
1757 /* packRegsForSupport :- reduce some registers for support calls */
1758 /*-----------------------------------------------------------------*/
1760 packRegsForSupport (iCode * ic, eBBlock * ebp)
1763 /* for the left & right operand :- look to see if the
1764 left was assigned a true symbol in far space in that
1765 case replace them */
1766 D (D_ALLOC, ("packRegsForSupport: running on ic %p\n", ic));
1768 if (IS_ITEMP (IC_LEFT (ic)) &&
1769 OP_SYMBOL (IC_LEFT (ic))->liveTo <= ic->seq)
1771 iCode *dic = findAssignToSym (IC_LEFT (ic), ic);
1777 /* found it we need to remove it from the
1779 for (sic = dic; sic != ic; sic = sic->next)
1780 bitVectUnSetBit (sic->rlive, IC_LEFT (ic)->key);
1782 IC_LEFT (ic)->operand.symOperand =
1783 IC_RIGHT (dic)->operand.symOperand;
1784 IC_LEFT (ic)->key = IC_RIGHT (dic)->operand.symOperand->key;
1785 remiCodeFromeBBlock (ebp, dic);
1786 bitVectUnSetBit(OP_SYMBOL(IC_RESULT(dic))->defs,dic->key);
1787 hTabDeleteItem (&iCodehTab, dic->key, dic, DELETE_ITEM, NULL);
1788 // PENDING: Check vs mcs51
1792 /* do the same for the right operand */
1795 IS_ITEMP (IC_RIGHT (ic)) &&
1796 OP_SYMBOL (IC_RIGHT (ic))->liveTo <= ic->seq)
1798 iCode *dic = findAssignToSym (IC_RIGHT (ic), ic);
1804 /* found it we need to remove it from the block */
1805 for (sic = dic; sic != ic; sic = sic->next)
1806 bitVectUnSetBit (sic->rlive, IC_RIGHT (ic)->key);
1808 IC_RIGHT (ic)->operand.symOperand =
1809 IC_RIGHT (dic)->operand.symOperand;
1810 IC_RIGHT (ic)->key = IC_RIGHT (dic)->operand.symOperand->key;
1812 remiCodeFromeBBlock (ebp, dic);
1813 bitVectUnSetBit(OP_SYMBOL(IC_RESULT(dic))->defs,dic->key);
1814 hTabDeleteItem (&iCodehTab, dic->key, dic, DELETE_ITEM, NULL);
1815 // PENDING: vs mcs51
1823 #define IS_OP_RUONLY(x) (x && IS_SYMOP(x) && OP_SYMBOL(x)->ruonly)
1825 /** Will reduce some registers for single use.
1828 packRegsForOneuse (iCode * ic, operand * op, eBBlock * ebp)
1834 D (D_ALLOC, ("packRegsForOneUse: running on ic %p\n", ic));
1836 /* if returning a literal then do nothing */
1840 /* only upto 2 bytes since we cannot predict
1841 the usage of b, & acc */
1842 if (getSize (operandType (op)) > 2)
1845 if (ic->op != RETURN &&
1849 /* this routine will mark the a symbol as used in one
1850 instruction use only && if the defintion is local
1851 (ie. within the basic block) && has only one definition &&
1852 that definiion is either a return value from a
1853 function or does not contain any variables in
1855 uses = bitVectCopy (OP_USES (op));
1856 bitVectUnSetBit (uses, ic->key); /* take away this iCode */
1857 if (!bitVectIsZero (uses)) /* has other uses */
1860 /* if it has only one defintion */
1861 if (bitVectnBitsOn (OP_DEFS (op)) > 1)
1862 return NULL; /* has more than one definition */
1864 /* get the that definition */
1866 hTabItemWithKey (iCodehTab,
1867 bitVectFirstBit (OP_DEFS (op)))))
1870 /* found the definition now check if it is local */
1871 if (dic->seq < ebp->fSeq ||
1872 dic->seq > ebp->lSeq)
1873 return NULL; /* non-local */
1875 /* now check if it is the return from a function call */
1876 if (dic->op == CALL || dic->op == PCALL)
1878 if (ic->op != SEND && ic->op != RETURN &&
1879 !POINTER_SET(ic) && !POINTER_GET(ic))
1881 OP_SYMBOL (op)->ruonly = 1;
1887 /* otherwise check that the definition does
1888 not contain any symbols in far space */
1889 if (isOperandInFarSpace (IC_LEFT (dic)) ||
1890 isOperandInFarSpace (IC_RIGHT (dic)) ||
1891 IS_OP_RUONLY (IC_LEFT (ic)) ||
1892 IS_OP_RUONLY (IC_RIGHT (ic)))
1897 /* if pointer set then make sure the pointer is one byte */
1898 if (POINTER_SET (dic))
1901 if (POINTER_GET (dic))
1906 /* also make sure the intervenening instructions
1907 don't have any thing in far space */
1908 for (dic = dic->next; dic && dic != ic; dic = dic->next)
1910 /* if there is an intervening function call then no */
1911 if (dic->op == CALL || dic->op == PCALL)
1913 /* if pointer set then make sure the pointer
1915 if (POINTER_SET (dic))
1918 if (POINTER_GET (dic))
1921 /* if address of & the result is remat the okay */
1922 if (dic->op == ADDRESS_OF &&
1923 OP_SYMBOL (IC_RESULT (dic))->remat)
1926 /* if left or right or result is in far space */
1927 if (isOperandInFarSpace (IC_LEFT (dic)) ||
1928 isOperandInFarSpace (IC_RIGHT (dic)) ||
1929 isOperandInFarSpace (IC_RESULT (dic)) ||
1930 IS_OP_RUONLY (IC_LEFT (dic)) ||
1931 IS_OP_RUONLY (IC_RIGHT (dic)) ||
1932 IS_OP_RUONLY (IC_RESULT (dic)))
1938 OP_SYMBOL (op)->ruonly = 1;
1942 /*-----------------------------------------------------------------*/
1943 /* isBitwiseOptimizable - requirements of JEAN LOUIS VERN */
1944 /*-----------------------------------------------------------------*/
1946 isBitwiseOptimizable (iCode * ic)
1948 sym_link *rtype = getSpec (operandType (IC_RIGHT (ic)));
1950 /* bitwise operations are considered optimizable
1951 under the following conditions (Jean-Louis VERN)
1963 if (IS_LITERAL (rtype))
1969 Certian assignments involving pointers can be temporarly stored
1980 #if !DISABLE_PACKREGSFORACCUSE
1983 /** Pack registers for acc use.
1984 When the result of this operation is small and short lived it may
1985 be able to be stored in the accumelator.
1988 packRegsForAccUse (iCode * ic)
1992 /* if this is an aggregate, e.g. a one byte char array */
1993 if (IS_AGGREGATE(operandType(IC_RESULT(ic)))) {
1997 /* if + or - then it has to be one byte result */
1998 if ((ic->op == '+' || ic->op == '-')
1999 && getSize (operandType (IC_RESULT (ic))) > 1)
2002 /* if shift operation make sure right side is not a literal */
2003 if (ic->op == RIGHT_OP &&
2004 (isOperandLiteral (IC_RIGHT (ic)) ||
2005 getSize (operandType (IC_RESULT (ic))) > 1))
2008 if (ic->op == LEFT_OP &&
2009 (isOperandLiteral (IC_RIGHT (ic)) ||
2010 getSize (operandType (IC_RESULT (ic))) > 1))
2013 /* has only one definition */
2014 if (bitVectnBitsOn (OP_DEFS (IC_RESULT (ic))) > 1)
2017 /* has only one use */
2018 if (bitVectnBitsOn (OP_USES (IC_RESULT (ic))) > 1)
2021 /* and the usage immediately follows this iCode */
2022 if (!(uic = hTabItemWithKey (iCodehTab,
2023 bitVectFirstBit (OP_USES (IC_RESULT (ic))))))
2026 if (ic->next != uic)
2029 /* if it is a conditional branch then we definitely can */
2033 if (uic->op == JUMPTABLE)
2037 /* if the usage is not is an assignment or an
2038 arithmetic / bitwise / shift operation then not */
2039 if (POINTER_SET (uic) &&
2040 getSize (aggrToPtr (operandType (IC_RESULT (uic)), FALSE)) > 1)
2044 if (uic->op != '=' &&
2045 !IS_ARITHMETIC_OP (uic) &&
2046 !IS_BITWISE_OP (uic) &&
2047 uic->op != LEFT_OP &&
2048 uic->op != RIGHT_OP)
2051 /* if used in ^ operation then make sure right is not a
2053 if (uic->op == '^' && isOperandLiteral (IC_RIGHT (uic)))
2056 /* if shift operation make sure right side is not a literal */
2057 if (uic->op == RIGHT_OP &&
2058 (isOperandLiteral (IC_RIGHT (uic)) ||
2059 getSize (operandType (IC_RESULT (uic))) > 1))
2062 if (uic->op == LEFT_OP &&
2063 (isOperandLiteral (IC_RIGHT (uic)) ||
2064 getSize (operandType (IC_RESULT (uic))) > 1))
2068 /* make sure that the result of this icode is not on the
2069 stack, since acc is used to compute stack offset */
2070 if (IS_TRUE_SYMOP (IC_RESULT (uic)) &&
2071 OP_SYMBOL (IC_RESULT (uic))->onStack)
2076 /* if either one of them in far space then we cannot */
2077 if ((IS_TRUE_SYMOP (IC_LEFT (uic)) &&
2078 isOperandInFarSpace (IC_LEFT (uic))) ||
2079 (IS_TRUE_SYMOP (IC_RIGHT (uic)) &&
2080 isOperandInFarSpace (IC_RIGHT (uic))))
2084 /* if the usage has only one operand then we can */
2085 if (IC_LEFT (uic) == NULL ||
2086 IC_RIGHT (uic) == NULL)
2089 /* make sure this is on the left side if not
2090 a '+' since '+' is commutative */
2091 if (ic->op != '+' &&
2092 IC_LEFT (uic)->key != IC_RESULT (ic)->key)
2095 // See mcs51 ralloc for reasoning
2097 /* if one of them is a literal then we can */
2098 if ((IC_LEFT (uic) && IS_OP_LITERAL (IC_LEFT (uic))) ||
2099 (IC_RIGHT (uic) && IS_OP_LITERAL (IC_RIGHT (uic))))
2106 /** This is confusing :) Guess for now */
2107 if (IC_LEFT (uic)->key == IC_RESULT (ic)->key &&
2108 (IS_ITEMP (IC_RIGHT (uic)) ||
2109 (IS_TRUE_SYMOP (IC_RIGHT (uic)))))
2112 if (IC_RIGHT (uic)->key == IC_RESULT (ic)->key &&
2113 (IS_ITEMP (IC_LEFT (uic)) ||
2114 (IS_TRUE_SYMOP (IC_LEFT (uic)))))
2118 OP_SYMBOL (IC_RESULT (ic))->accuse = ACCUSE_A;
2123 packRegsForHLUse (iCode * ic)
2127 /* PENDING: Could do IFX */
2133 /* has only one definition */
2134 if (bitVectnBitsOn (OP_DEFS (IC_RESULT (ic))) > 1)
2136 D (D_HLUSE, (" + Dropping as has more than one def\n"));
2140 /* has only one use */
2141 if (bitVectnBitsOn (OP_USES (IC_RESULT (ic))) > 1)
2143 D (D_HLUSE, (" + Dropping as has more than one use\n"));
2147 /* and the usage immediately follows this iCode */
2148 if (!(uic = hTabItemWithKey (iCodehTab,
2149 bitVectFirstBit (OP_USES (IC_RESULT (ic))))))
2151 D (D_HLUSE, (" + Dropping as usage isn't in this block\n"));
2155 if (ic->next != uic)
2157 D (D_HLUSE, (" + Dropping as usage doesn't follow this\n"));
2166 if (getSize (operandType (IC_RESULT (ic))) != 2 ||
2167 (IC_LEFT(uic) && getSize (operandType (IC_LEFT (uic))) != 2) ||
2168 (IC_RIGHT(uic) && getSize (operandType (IC_RIGHT (uic))) != 2))
2170 D (D_HLUSE, (" + Dropping as the result size is not 2\n"));
2176 if (ic->op == CAST && uic->op == IPUSH)
2178 if (ic->op == ADDRESS_OF && uic->op == IPUSH)
2180 if (ic->op == ADDRESS_OF && POINTER_GET (uic) && IS_ITEMP( IC_RESULT (uic)))
2182 if (ic->op == CALL && ic->parmBytes == 0 && (uic->op == '-' || uic->op == '+'))
2187 /* Case of assign a constant to offset in a static array. */
2188 if (ic->op == '+' && IS_VALOP (IC_RIGHT (ic)))
2190 if (uic->op == '=' && POINTER_SET (uic))
2194 else if (uic->op == IPUSH && getSize (operandType (IC_LEFT (uic))) == 2)
2201 D (D_HLUSE, (" + Dropping as it's a bad op\n"));
2204 OP_SYMBOL (IC_RESULT (ic))->accuse = ACCUSE_SCRATCH;
2208 packRegsForHLUse3 (iCode * lic, operand * op, eBBlock * ebp)
2213 bool isFirst = TRUE;
2215 D (D_PACK_HLUSE3, ("Checking HL on %p lic key %u first def %u line %u:\n", OP_SYMBOL(op), lic->key, bitVectFirstBit(OP_DEFS(op)), lic->lineno));
2219 if ( OP_SYMBOL(op)->accuse)
2224 if (OP_SYMBOL(op)->remat)
2229 /* Only defined once */
2230 if (bitVectnBitsOn (OP_DEFS (op)) > 1)
2233 if (getSize (operandType (op)) > 2)
2236 /* And this is the definition */
2237 if (bitVectFirstBit (OP_DEFS (op)) != lic->key)
2240 /* first check if any overlapping liverange has already been
2242 if (OP_SYMBOL(op)->clashes)
2244 for (i = 0 ; i < OP_SYMBOL(op)->clashes->size ; i++ )
2246 if (bitVectBitValue(OP_SYMBOL(op)->clashes,i))
2248 sym = hTabItemWithKey(liveRanges,i);
2249 if (sym->accuse == ACCUSE_SCRATCH)
2257 /* Nothing else that clashes with this is using the scratch
2258 register. Scan through all of the intermediate instructions and
2259 see if any of them could nuke HL.
2261 dic = ic = hTabFirstItemWK(iCodeSeqhTab,OP_SYMBOL(op)->liveFrom);
2263 for (; ic && ic->seq <= OP_SYMBOL(op)->liveTo;
2264 ic = hTabNextItem(iCodeSeqhTab, &key))
2268 D (D_PACK_HLUSE3, ("(On %p: op: %u next: %p)\n", ic, ic->op, ic->next));
2273 if (ic->op == ADDRESS_OF)
2275 if (POINTER_GET (ic))
2277 if (ic->op == '=' && !POINTER_SET(ic))
2281 if (IC_RESULT(ic) && IS_SYMOP(IC_RESULT(ic))
2282 && isOperandInDirSpace (IC_RESULT (ic)))
2285 if (IC_LEFT(ic) && IS_SYMOP(IC_LEFT(ic))
2286 && isOperandInDirSpace (IC_LEFT (ic)))
2289 if (IC_RIGHT(ic) && IS_SYMOP(IC_RIGHT(ic))
2290 && isOperandInDirSpace (IC_RIGHT (ic)))
2293 /* Handle the non left/right/result ones first */
2296 if (ic->op == JUMPTABLE)
2305 if (ic->op == IPUSH && isOperandEqual (op, IC_LEFT (ic)))
2308 if (ic->op == SEND && isOperandEqual (op, IC_LEFT (ic)))
2311 if (ic->op == CALL && isOperandEqual (op, IC_RESULT (ic)))
2314 if (ic->op == LEFT_OP && isOperandLiteral (IC_RIGHT (ic)))
2317 if ((ic->op == '=' && !POINTER_SET(ic)) ||
2318 ic->op == UNARYMINUS ||
2327 if (ic->op == '*' && isOperandEqual (op, IC_LEFT (ic)))
2330 if (POINTER_SET (ic) && isOperandEqual (op, IC_RESULT (ic)))
2333 if (POINTER_GET (ic) && isOperandEqual (op, IC_LEFT (ic)))
2336 if (IS_VALOP (IC_RIGHT (ic)) &&
2343 /* By default give up */
2347 D (D_PACK_HLUSE3, ("Succeeded!\n"))
2349 OP_SYMBOL (op)->accuse = ACCUSE_SCRATCH;
2354 packRegsForIYUse (iCode * lic, operand * op, eBBlock * ebp)
2361 D (D_PACK_IY, ("Checking IY on %p lic key %u first def %u line %u:\n", OP_SYMBOL(op), lic->key, bitVectFirstBit(OP_DEFS(op)), lic->lineno));
2365 if ( OP_SYMBOL(op)->accuse)
2370 if (OP_SYMBOL(op)->remat)
2375 /* Only defined once */
2376 if (bitVectnBitsOn (OP_DEFS (op)) > 1)
2379 /* And this is the definition */
2380 if (bitVectFirstBit (OP_DEFS (op)) != lic->key)
2383 /* first check if any overlapping liverange has already been
2385 if (OP_SYMBOL(op)->clashes)
2387 for (i = 0 ; i < OP_SYMBOL(op)->clashes->size ; i++ )
2389 if (bitVectBitValue(OP_SYMBOL(op)->clashes,i))
2391 sym = hTabItemWithKey(liveRanges,i);
2392 if (sym->accuse == ACCUSE_IY)
2400 /* Only a few instructions can load into IY */
2406 if (getSize (operandType (op)) != 2)
2408 D (D_ACCUSE2, (" + Dropping as operation has size is too big\n"));
2412 /* Nothing else that clashes with this is using the scratch
2413 register. Scan through all of the intermediate instructions and
2414 see if any of them could nuke HL.
2416 dic = ic = hTabFirstItemWK(iCodeSeqhTab,OP_SYMBOL(op)->liveFrom);
2419 for (; ic && ic->seq <= OP_SYMBOL(op)->liveTo;
2420 ic = hTabNextItem(iCodeSeqhTab,&key))
2425 if (ic->op == PCALL ||
2434 /* Be pessamistic. */
2438 D (D_PACK_IY, (" op: %u uses %u result: %d left: %d right: %d\n", ic->op, bitVectBitValue(uses, ic->key),
2439 IC_RESULT(ic) && IS_SYMOP(IC_RESULT(ic)) ? isOperandInDirSpace(IC_RESULT(ic)) : -1,
2440 IC_LEFT(ic) && IS_SYMOP(IC_LEFT(ic)) ? isOperandInDirSpace(IC_LEFT(ic)) : -1,
2441 IC_RIGHT(ic) && IS_SYMOP(IC_RIGHT(ic)) ? isOperandInDirSpace(IC_RIGHT(ic)) : -1
2444 if (IC_RESULT(ic) && IS_SYMOP(IC_RESULT(ic)) &&
2445 isOperandInDirSpace(IC_RESULT(ic)))
2448 if (IC_RIGHT(ic) && IS_SYMOP(IC_RIGHT(ic)) &&
2449 isOperandInDirSpace(IC_RIGHT(ic)))
2452 if (IC_LEFT(ic) && IS_SYMOP(IC_LEFT(ic)) &&
2453 isOperandInDirSpace(IC_LEFT(ic)))
2456 /* Only certain rules will work against IY. Check if this iCode uses
2458 if (bitVectBitValue(uses, ic->key) != 0)
2460 if (ic->op == '=' &&
2461 isOperandEqual(IC_RESULT(ic), op))
2464 if (ic->op == GET_VALUE_AT_ADDRESS &&
2465 isOperandEqual(IC_LEFT(ic), op))
2468 if (isOperandEqual(IC_RESULT(ic), IC_LEFT(ic)) == FALSE)
2471 if (IC_RIGHT (ic) && IS_VALOP (IC_RIGHT (ic)))
2473 if (ic->op == '+' ||
2476 /* Only works if the constant is small */
2477 if (operandLitValue (IC_RIGHT (ic)) < 4)
2486 /* This iCode doesn't use the sym. See if this iCode preserves IY.
2491 /* By default give up */
2495 D (D_PACK_IY, ("Succeeded IY!\n"));
2497 OP_SYMBOL (op)->accuse = ACCUSE_IY;
2501 /** Returns TRUE if this operation can use acc and if it preserves the value.
2504 opPreservesA (iCode * uic)
2508 /* If we've gotten this far then the thing to compare must be
2509 small enough and must be in A.
2514 if (uic->op == JUMPTABLE)
2516 D (D_ACCUSE2, (" + Dropping as operation is a Jumptable\n"));
2520 /* A pointer assign preserves A if A is the left value. */
2521 if (uic->op == '=' && POINTER_SET (uic))
2526 /* if the usage has only one operand then we can */
2527 /* PENDING: check */
2528 if (IC_LEFT (uic) == NULL ||
2529 IC_RIGHT (uic) == NULL)
2531 D (D_ACCUSE2, (" + Dropping as operation has only one operand\n"));
2535 /* PENDING: check this rule */
2536 if (getSize (operandType (IC_RESULT (uic))) > 1)
2538 D (D_ACCUSE2, (" + Dropping as operation has size is too big\n"));
2543 /* Disabled all of the old rules as they weren't verified and have
2544 caused at least one problem.
2549 /** Returns true if this operand preserves the value of A.
2552 opIgnoresA (iCode * ic, iCode * uic)
2554 /* A increment of an iTemp by a constant is OK. */
2555 if ( uic->op == '+' &&
2556 IS_ITEMP (IC_LEFT (uic)) &&
2557 IS_ITEMP (IC_RESULT (uic)) &&
2558 IS_OP_LITERAL (IC_RIGHT (uic)))
2560 unsigned int icount = (unsigned int) floatFromVal (IC_RIGHT (uic)->operand.valOperand);
2562 /* Being an ITEMP means that we're already a symbol. */
2564 IC_RESULT (uic)->operand.symOperand->key == IC_LEFT (uic)->operand.symOperand->key
2570 else if (uic->op == '=' && !POINTER_SET (uic))
2572 /* If they are equal and get optimised out then things are OK. */
2573 if (isOperandEqual (IC_RESULT (uic), IC_RIGHT (uic)))
2575 /* Straight assign is OK. */
2584 /* Some optimisation cases:
2596 ; genAssign (pointer)
2600 want to optimise down to:
2606 So genPointer get is OK
2607 genPlus where the right is constant, left is iTemp, and result is same as left
2608 genAssign (pointer) is OK
2619 ; genAssign (pointer)
2620 ; AOP_STK for _strcpy_to_1_1
2625 want to optimise down to:
2631 So genIfx where IC_COND has size of 1 and is a constant.
2634 /** Pack registers for acc use.
2635 When the result of this operation is small and short lived it may
2636 be able to be stored in the accumulator.
2638 Note that the 'A preserving' list is currently emperical :)
2641 packRegsForAccUse2 (iCode * ic)
2645 D (D_ACCUSE2, ("packRegsForAccUse2: running on ic %p line %u\n", ic, ic->lineno));
2649 /* Filter out all but those 'good' commands */
2651 !POINTER_GET (ic) &&
2654 !IS_BITWISE_OP (ic) &&
2660 ic->op != GETHBIT &&
2663 D (D_ACCUSE2, (" + Dropping as not a 'good' source command\n"));
2667 /* if + or - then it has to be one byte result.
2670 if ((ic->op == '+' || ic->op == '-')
2671 && getSize (operandType (IC_RESULT (ic))) > 1)
2673 D (D_ACCUSE2, (" + Dropping as it's a big + or -\n"));
2677 /* has only one definition */
2678 if (bitVectnBitsOn (OP_DEFS (IC_RESULT (ic))) > 1)
2680 D (D_ACCUSE2, (" + Dropping as it has more than one definition\n"));
2684 /* Right. We may be able to propagate it through if:
2685 For each in the chain of uses the intermediate is OK.
2687 /* Get next with 'uses result' bit on
2688 If this->next == next
2689 Validate use of next
2690 If OK, increase count
2692 /* and the usage immediately follows this iCode */
2693 if (!(uic = hTabItemWithKey (iCodehTab,
2694 bitVectFirstBit (OP_USES (IC_RESULT (ic))))))
2696 D (D_ACCUSE2, (" + Dropping as usage does not follow first\n"));
2701 /* Create a copy of the OP_USES bit vect */
2702 bitVect *uses = bitVectCopy (OP_USES (IC_RESULT (ic)));
2704 iCode *scan = ic, *next;
2708 setBit = bitVectFirstBit (uses);
2709 next = hTabItemWithKey (iCodehTab, setBit);
2710 if (scan->next == next)
2712 D (D_ACCUSE2_VERBOSE, (" ! Is next in line\n"));
2714 bitVectUnSetBit (uses, setBit);
2715 /* Still contigous. */
2716 if (!opPreservesA (next))
2718 D (D_ACCUSE2, (" + Dropping as operation doesn't preserve A\n"));
2721 D (D_ACCUSE2_VERBOSE, (" ! Preserves A, so continue scanning\n"));
2724 else if (scan->next == NULL && bitVectnBitsOn (uses) == 1 && next != NULL)
2726 if (next->prev == NULL)
2728 if (!opPreservesA (next))
2730 D (D_ACCUSE2, (" + Dropping as operation doesn't preserve A #2\n"));
2733 bitVectUnSetBit (uses, setBit);
2738 D (D_ACCUSE2, (" + Dropping as last in list and next doesn't start a block\n"));
2742 else if (scan->next == NULL)
2744 D (D_ACCUSE2, (" + Dropping as hit the end of the list\n"));
2745 D (D_ACCUSE2, (" + Next in htab: %p\n", next));
2750 if (opIgnoresA (ic, scan->next))
2754 D (D_ACCUSE2_VERBOSE, (" ! Op ignores A, so continue scanning\n"));
2758 D (D_ACCUSE2, (" + Dropping as parts are not consecuitive and intermediate might use A\n"));
2763 while (!bitVectIsZero (uses));
2765 OP_SYMBOL (IC_RESULT (ic))->accuse = ACCUSE_A;
2770 /** Does some transformations to reduce register pressure.
2773 packRegisters (eBBlock * ebp)
2778 D (D_ALLOC, ("packRegisters: entered.\n"));
2780 while (1 && !DISABLE_PACK_ASSIGN)
2783 /* look for assignments of the form */
2784 /* iTempNN = TRueSym (someoperation) SomeOperand */
2786 /* TrueSym := iTempNN:1 */
2787 for (ic = ebp->sch; ic; ic = ic->next)
2789 /* find assignment of the form TrueSym := iTempNN:1 */
2790 if (ic->op == '=' && !POINTER_SET (ic))
2791 change += packRegsForAssign (ic, ebp);
2797 for (ic = ebp->sch; ic; ic = ic->next)
2799 /* Safe: address of a true sym is always constant. */
2800 /* if this is an itemp & result of a address of a true sym
2801 then mark this as rematerialisable */
2802 D (D_ALLOC, ("packRegisters: looping on ic %p\n", ic));
2804 if (ic->op == ADDRESS_OF &&
2805 IS_ITEMP (IC_RESULT (ic)) &&
2806 IS_TRUE_SYMOP (IC_LEFT (ic)) &&
2807 bitVectnBitsOn (OP_DEFS (IC_RESULT (ic))) == 1 &&
2808 !OP_SYMBOL (IC_LEFT (ic))->onStack)
2811 OP_SYMBOL (IC_RESULT (ic))->remat = 1;
2812 OP_SYMBOL (IC_RESULT (ic))->rematiCode = ic;
2813 OP_SYMBOL (IC_RESULT (ic))->usl.spillLoc = NULL;
2816 /* Safe: just propagates the remat flag */
2817 /* if straight assignment then carry remat flag if this is the
2819 if (ic->op == '=' &&
2820 !POINTER_SET (ic) &&
2821 IS_SYMOP (IC_RIGHT (ic)) &&
2822 OP_SYMBOL (IC_RIGHT (ic))->remat &&
2823 bitVectnBitsOn (OP_SYMBOL (IC_RESULT (ic))->defs) <= 1)
2826 OP_SYMBOL (IC_RESULT (ic))->remat =
2827 OP_SYMBOL (IC_RIGHT (ic))->remat;
2828 OP_SYMBOL (IC_RESULT (ic))->rematiCode =
2829 OP_SYMBOL (IC_RIGHT (ic))->rematiCode;
2832 /* if the condition of an if instruction is defined in the
2833 previous instruction then mark the itemp as a conditional */
2834 if ((IS_CONDITIONAL (ic) ||
2835 ((ic->op == BITWISEAND ||
2838 isBitwiseOptimizable (ic))) &&
2839 ic->next && ic->next->op == IFX &&
2840 bitVectnBitsOn (OP_USES(IC_RESULT(ic)))==1 &&
2841 isOperandEqual (IC_RESULT (ic), IC_COND (ic->next)) &&
2842 OP_SYMBOL (IC_RESULT (ic))->liveTo <= ic->next->seq)
2845 OP_SYMBOL (IC_RESULT (ic))->regType = REG_CND;
2850 /* reduce for support function calls */
2851 if (ic->supportRtn || ic->op == '+' || ic->op == '-')
2852 packRegsForSupport (ic, ebp);
2855 /* some cases the redundant moves can
2856 can be eliminated for return statements */
2857 if (ic->op == RETURN || ic->op == SEND)
2859 packRegsForOneuse (ic, IC_LEFT (ic), ebp);
2862 /* if pointer set & left has a size more than
2863 one and right is not in far space */
2864 if (!DISABLE_PACK_ONE_USE &&
2866 /* MLH: no such thing.
2867 !isOperandInFarSpace(IC_RIGHT(ic)) && */
2868 !OP_SYMBOL (IC_RESULT (ic))->remat &&
2869 !IS_OP_RUONLY (IC_RIGHT (ic)) &&
2870 getSize (aggrToPtr (operandType (IC_RESULT (ic)), FALSE)) > 1)
2873 packRegsForOneuse (ic, IC_RESULT (ic), ebp);
2876 /* if pointer get */
2877 if (!DISABLE_PACK_ONE_USE &&
2879 /* MLH: dont have far space
2880 !isOperandInFarSpace(IC_RESULT(ic))&& */
2881 !OP_SYMBOL (IC_LEFT (ic))->remat &&
2882 !IS_OP_RUONLY (IC_RESULT (ic)) &&
2883 getSize (aggrToPtr (operandType (IC_LEFT (ic)), FALSE)) > 1)
2886 packRegsForOneuse (ic, IC_LEFT (ic), ebp);
2889 /* pack registers for accumulator use, when the result of an
2890 arithmetic or bit wise operation has only one use, that use is
2891 immediately following the defintion and the using iCode has
2892 only one operand or has two operands but one is literal & the
2893 result of that operation is not on stack then we can leave the
2894 result of this operation in acc:b combination */
2896 if (!DISABLE_PACK_HL && IS_ITEMP (IC_RESULT (ic)))
2899 packRegsForHLUse (ic);
2901 packRegsForHLUse3 (ic, IC_RESULT (ic), ebp);
2904 if (!DISABLE_PACK_IY && IS_ITEMP (IC_RESULT (ic)) && IS_Z80)
2906 packRegsForIYUse (ic, IC_RESULT (ic), ebp);
2909 if (!DISABLE_PACK_ACC && IS_ITEMP (IC_RESULT (ic)) &&
2910 getSize (operandType (IC_RESULT (ic))) == 1)
2912 packRegsForAccUse2 (ic);
2917 /** Joins together two byte constant pushes into one word push.
2920 joinPushes (iCode *lic)
2924 for (ic = lic; ic; ic = ic->next)
2931 /* Anything past this? */
2936 /* This and the next pushes? */
2937 if (ic->op != IPUSH || uic->op != IPUSH)
2941 /* Both literals? */
2942 if ( !IS_OP_LITERAL (IC_LEFT (ic)) || !IS_OP_LITERAL (IC_LEFT (uic)))
2946 /* Both characters? */
2947 if ( getSize (operandType (IC_LEFT (ic))) != 1 || getSize (operandType (IC_LEFT (uic))) != 1)
2951 /* Pull out the values, make a new type, and create the new iCode for it.
2953 first = (int)operandLitValue ( IC_LEFT (ic));
2954 second = (int)operandLitValue ( IC_LEFT (uic));
2956 sprintf (buffer, "%u", ((first << 8) | (second & 0xFF)) & 0xFFFFU);
2957 val = constVal (buffer);
2958 SPEC_NOUN (val->type) = V_INT;
2959 IC_LEFT (ic)->operand.valOperand = val;
2961 /* Now remove the second one from the list. */
2962 ic->next = uic->next;
2965 /* Patch up the reverse link */
2966 uic->next->prev = ic;
2973 /*-----------------------------------------------------------------*/
2974 /* assignRegisters - assigns registers to each live range as need */
2975 /*-----------------------------------------------------------------*/
2977 z80_assignRegisters (eBBlock ** ebbs, int count)
2982 D (D_ALLOC, ("\n-> z80_assignRegisters: entered.\n"));
2984 setToNull ((void *) &_G.funcrUsed);
2985 setToNull ((void *) &_G.totRegAssigned);
2986 _G.stackExtend = _G.dataExtend = 0;
2990 /* DE is required for the code gen. */
2991 _G.nRegs = GBZ80_MAX_REGS;
2992 regsZ80 = _gbz80_regs;
2996 _G.nRegs = Z80_MAX_REGS;
2997 regsZ80 = _z80_regs;
3000 /* change assignments this will remove some
3001 live ranges reducing some register pressure */
3002 for (i = 0; i < count; i++)
3003 packRegisters (ebbs[i]);
3005 if (options.dump_pack)
3006 dumpEbbsToFileExt (DUMP_PACK, ebbs, count);
3008 /* first determine for each live range the number of
3009 registers & the type of registers required for each */
3012 /* and serially allocate registers */
3013 serialRegAssign (ebbs, count);
3018 /* if stack was extended then tell the user */
3021 /* werror(W_TOOMANY_SPILS,"stack", */
3022 /* _G.stackExtend,currFunc->name,""); */
3028 /* werror(W_TOOMANY_SPILS,"data space", */
3029 /* _G.dataExtend,currFunc->name,""); */
3033 if (options.dump_rassgn) {
3034 dumpEbbsToFileExt (DUMP_RASSGN, ebbs, count);
3035 dumpLiveRanges (DUMP_LRANGE, liveRanges);
3038 /* after that create the register mask
3039 for each of the instruction */
3040 createRegMask (ebbs, count);
3042 /* now get back the chain */
3043 ic = iCodeLabelOptimize (iCodeFromeBBlock (ebbs, count));
3045 ic = joinPushes (ic);
3047 /* redo that offsets for stacked automatic variables */
3048 redoStackOffsets ();
3052 /* free up any stackSpil locations allocated */
3053 applyToSet (_G.stackSpil, deallocStackSpil);
3055 setToNull ((void **) &_G.stackSpil);
3056 setToNull ((void **) &_G.spiltSet);
3057 /* mark all registers as free */