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"));
800 /* just to make the compiler happy */
804 /** Symbol has a given register.
807 symHasReg (symbol * sym, regs * reg)
811 for (i = 0; i < sym->nRegs; i++)
812 if (sym->regs[i] == reg)
818 /** Check the live to and if they have registers & are not spilt then
819 free up the registers
822 deassignLRs (iCode * ic, eBBlock * ebp)
828 for (sym = hTabFirstItem (liveRanges, &k); sym;
829 sym = hTabNextItem (liveRanges, &k))
833 /* if it does not end here */
834 if (sym->liveTo > ic->seq)
837 /* if it was spilt on stack then we can
838 mark the stack spil location as free */
843 sym->usl.spillLoc->isFree = 1;
849 if (!bitVectBitValue (_G.regAssigned, sym->key))
852 /* special case check if this is an IFX &
853 the privious one was a pop and the
854 previous one was not spilt then keep track
856 if (ic->op == IFX && ic->prev &&
857 ic->prev->op == IPOP &&
858 !ic->prev->parmPush &&
859 !OP_SYMBOL (IC_LEFT (ic->prev))->isspilt)
860 psym = OP_SYMBOL (IC_LEFT (ic->prev));
862 D (D_ALLOC, ("deassignLRs: in loop on sym %p nregs %u\n", sym, sym->nRegs));
868 bitVectUnSetBit (_G.regAssigned, sym->key);
870 /* if the result of this one needs registers
871 and does not have it then assign it right
873 if (IC_RESULT (ic) &&
874 !(SKIP_IC2 (ic) || /* not a special icode */
875 ic->op == JUMPTABLE ||
880 (result = OP_SYMBOL (IC_RESULT (ic))) && /* has a result */
881 result->liveTo > ic->seq && /* and will live beyond this */
882 result->liveTo <= ebp->lSeq && /* does not go beyond this block */
883 result->regType == sym->regType && /* same register types */
884 result->nRegs && /* which needs registers */
885 !result->isspilt && /* and does not already have them */
887 !bitVectBitValue (_G.regAssigned, result->key) &&
888 /* the number of free regs + number of regs in this LR
889 can accomodate the what result Needs */
890 ((nfreeRegsType (result->regType) +
891 sym->nRegs) >= result->nRegs)
894 for (i = 0; i < result->nRegs; i++)
897 result->regs[i] = sym->regs[i];
899 result->regs[i] = getRegGpr (ic, ebp, result);
901 /* if the allocation falied which means
902 this was spilt then break */
903 if (!result->regs[i])
911 _G.regAssigned = bitVectSetBit (_G.regAssigned, result->key);
912 _G.totRegAssigned = bitVectSetBit (_G.totRegAssigned, result->key);
915 /* free the remaining */
916 for (; i < sym->nRegs; i++)
920 if (!symHasReg (psym, sym->regs[i]))
921 freeReg (sym->regs[i]);
924 freeReg (sym->regs[i]);
925 // sym->regs[i] = NULL;
932 /** Reassign this to registers.
935 reassignLR (operand * op)
937 symbol *sym = OP_SYMBOL (op);
940 D (D_ALLOC, ("reassingLR: on sym %p\n", sym));
942 /* not spilt any more */
943 sym->isspilt = sym->spillA = sym->blockSpil = sym->remainSpil = 0;
944 bitVectUnSetBit (_G.spiltSet, sym->key);
946 _G.regAssigned = bitVectSetBit (_G.regAssigned, sym->key);
947 _G.totRegAssigned = bitVectSetBit (_G.totRegAssigned, sym->key);
951 for (i = 0; i < sym->nRegs; i++)
952 sym->regs[i]->isFree = 0;
955 /** Determines if allocating will cause a spill.
958 willCauseSpill (int nr, int rt)
960 /* first check if there are any avlb registers
961 of te type required */
962 if (nFreeRegs (0) >= nr)
965 /* it will cause a spil */
969 /** The allocator can allocate same registers to result and operand,
970 if this happens make sure they are in the same position as the operand
971 otherwise chaos results.
974 positionRegs (symbol * result, symbol * opsym)
976 int count = min (result->nRegs, opsym->nRegs);
977 int i, j = 0, shared = 0;
980 D (D_ALLOC, ("positionRegs: on result %p opsum %p line %u\n", result, opsym, lineno));
982 /* if the result has been spilt then cannot share */
987 /* first make sure that they actually share */
988 for (i = 0; i < count; i++)
990 for (j = 0; j < count; j++)
992 if (result->regs[i] == opsym->regs[j] && i != j)
1002 regs *tmp = result->regs[i];
1003 result->regs[i] = result->regs[j];
1004 result->regs[j] = tmp;
1011 /** Try to allocate a pair of registers to the symbol.
1014 tryAllocatingRegPair (symbol * sym)
1017 wassert (sym->nRegs == 2);
1018 for (i = 0; i < _G.nRegs; i += 2)
1020 if ((regsZ80[i].isFree) && (regsZ80[i + 1].isFree))
1022 regsZ80[i].isFree = 0;
1023 sym->regs[0] = ®sZ80[i];
1024 regsZ80[i + 1].isFree = 0;
1025 sym->regs[1] = ®sZ80[i + 1];
1026 sym->regType = REG_PAIR;
1030 currFunc->regsUsed =
1031 bitVectSetBit (currFunc->regsUsed, i);
1032 currFunc->regsUsed =
1033 bitVectSetBit (currFunc->regsUsed, i + 1);
1035 D (D_ALLOC, ("tryAllocRegPair: succeded for sym %p\n", sym));
1039 D (D_ALLOC, ("tryAllocRegPair: failed on sym %p\n", sym));
1043 /** Serially allocate registers to the variables.
1044 This is the main register allocation function. It is called after
1048 serialRegAssign (eBBlock ** ebbs, int count)
1052 /* for all blocks */
1053 for (i = 0; i < count; i++)
1058 if (ebbs[i]->noPath &&
1059 (ebbs[i]->entryLabel != entryLabel &&
1060 ebbs[i]->entryLabel != returnLabel))
1063 /* of all instructions do */
1064 for (ic = ebbs[i]->sch; ic; ic = ic->next)
1067 /* if this is an ipop that means some live
1068 range will have to be assigned again */
1072 reassignLR (IC_LEFT (ic));
1075 /* if result is present && is a true symbol */
1076 if (IC_RESULT (ic) && ic->op != IFX &&
1077 IS_TRUE_SYMOP (IC_RESULT (ic)))
1078 OP_SYMBOL (IC_RESULT (ic))->allocreq++;
1080 /* take away registers from live
1081 ranges that end at this instruction */
1082 deassignLRs (ic, ebbs[i]);
1084 /* some don't need registers */
1085 /* MLH: removed RESULT and POINTER_SET condition */
1086 if (SKIP_IC2 (ic) ||
1087 ic->op == JUMPTABLE ||
1093 /* now we need to allocate registers only for the result */
1096 symbol *sym = OP_SYMBOL (IC_RESULT (ic));
1101 D (D_ALLOC, ("serialRegAssign: in loop on result %p\n", sym));
1103 /* if it does not need or is spilt
1104 or is already assigned to registers
1105 or will not live beyond this instructions */
1108 bitVectBitValue (_G.regAssigned, sym->key) ||
1109 sym->liveTo <= ic->seq)
1111 D (D_ALLOC, ("serialRegAssign: wont live long enough.\n"));
1115 /* if some liverange has been spilt at the block level
1116 and this one live beyond this block then spil this
1118 if (_G.blockSpil && sym->liveTo > ebbs[i]->lSeq)
1120 D (D_ALLOC, ("serialRegAssign: \"spilling to be safe.\"\n"));
1124 /* if trying to allocate this will cause
1125 a spill and there is nothing to spill
1126 or this one is rematerializable then
1128 willCS = willCauseSpill (sym->nRegs, sym->regType);
1129 spillable = computeSpillable (ic);
1131 (willCS && bitVectIsZero (spillable)))
1134 D (D_ALLOC, ("serialRegAssign: \"remat spill\"\n"));
1140 /* if it has a spillocation & is used less than
1141 all other live ranges then spill this */
1143 if (sym->usl.spillLoc) {
1144 symbol *leastUsed = leastUsedLR (liveRangesWith (spillable,
1145 allLRs, ebbs[i], ic));
1146 if (leastUsed && leastUsed->used > sym->used) {
1151 /* if none of the liveRanges have a spillLocation then better
1152 to spill this one than anything else already assigned to registers */
1153 if (liveRangesWith(spillable,noSpilLoc,ebbs[i],ic)) {
1154 /* if this is local to this block then we might find a block spil */
1155 if (!(sym->liveFrom >= ebbs[i]->fSeq && sym->liveTo <= ebbs[i]->lSeq)) {
1163 /* else we assign registers to it */
1164 _G.regAssigned = bitVectSetBit (_G.regAssigned, sym->key);
1165 _G.totRegAssigned = bitVectSetBit (_G.totRegAssigned, sym->key);
1167 /* Special case: Try to fit into a reg pair if
1169 D (D_ALLOC, ("serialRegAssign: actually allocing regs!\n"));
1170 if ((sym->nRegs == 2) && tryAllocatingRegPair (sym))
1175 for (j = 0; j < sym->nRegs; j++)
1177 sym->regs[j] = getRegGpr (ic, ebbs[i], sym);
1179 /* if the allocation falied which means
1180 this was spilt then break */
1183 D (D_ALLOC, ("Couldnt alloc (spill)\n"))
1188 /* if it shares registers with operands make sure
1189 that they are in the same position */
1190 if (IC_LEFT (ic) && IS_SYMOP (IC_LEFT (ic)) &&
1191 OP_SYMBOL (IC_LEFT (ic))->nRegs && ic->op != '=')
1192 positionRegs (OP_SYMBOL (IC_RESULT (ic)),
1193 OP_SYMBOL (IC_LEFT (ic)));
1194 /* do the same for the right operand */
1195 if (IC_RIGHT (ic) && IS_SYMOP (IC_RIGHT (ic)) &&
1196 OP_SYMBOL (IC_RIGHT (ic))->nRegs)
1197 positionRegs (OP_SYMBOL (IC_RESULT (ic)),
1198 OP_SYMBOL (IC_RIGHT (ic)));
1205 /*-----------------------------------------------------------------*/
1206 /* fillGaps - Try to fill in the Gaps left by Pass1 */
1207 /*-----------------------------------------------------------------*/
1208 static void fillGaps()
1213 if (getenv("DISABLE_FILL_GAPS")) return;
1215 /* look for livernages that was spilt by the allocator */
1216 for (sym = hTabFirstItem(liveRanges,&key) ; sym ;
1217 sym = hTabNextItem(liveRanges,&key)) {
1222 if (!sym->spillA || !sym->clashes || sym->remat) continue ;
1224 /* find the liveRanges this one clashes with, that are
1225 still assigned to registers & mark the registers as used*/
1226 for ( i = 0 ; i < sym->clashes->size ; i ++) {
1230 if (bitVectBitValue(sym->clashes,i) == 0 || /* those that clash with this */
1231 bitVectBitValue(_G.totRegAssigned,i) == 0) /* and are still assigned to registers */
1234 clr = hTabItemWithKey(liveRanges,i);
1237 /* mark these registers as used */
1238 for (k = 0 ; k < clr->nRegs ; k++ )
1239 useReg(clr->regs[k]);
1242 if (willCauseSpill(sym->nRegs,sym->regType)) {
1243 /* NOPE :( clear all registers & and continue */
1248 /* THERE IS HOPE !!!! */
1249 for (i=0; i < sym->nRegs ; i++ ) {
1250 sym->regs[i] = getRegGprNoSpil ();
1253 /* for all its definitions check if the registers
1254 allocated needs positioning NOTE: we can position
1255 only ONCE if more than One positioning required
1258 for (i = 0 ; i < sym->defs->size ; i++ ) {
1259 if (bitVectBitValue(sym->defs,i)) {
1261 if (!(ic = hTabItemWithKey(iCodehTab,i))) continue ;
1262 if (SKIP_IC(ic)) continue;
1263 assert(isSymbolEqual(sym,OP_SYMBOL(IC_RESULT(ic)))); /* just making sure */
1264 /* if left is assigned to registers */
1265 if (IS_SYMOP(IC_LEFT(ic)) &&
1266 bitVectBitValue(_G.totRegAssigned,OP_SYMBOL(IC_LEFT(ic))->key)) {
1267 pdone += positionRegs(sym,OP_SYMBOL(IC_LEFT(ic)));
1269 if (IS_SYMOP(IC_RIGHT(ic)) &&
1270 bitVectBitValue(_G.totRegAssigned,OP_SYMBOL(IC_RIGHT(ic))->key)) {
1271 pdone += positionRegs(sym,OP_SYMBOL(IC_RIGHT(ic)));
1273 if (pdone > 1) break;
1276 for (i = 0 ; i < sym->uses->size ; i++ ) {
1277 if (bitVectBitValue(sym->uses,i)) {
1279 if (!(ic = hTabItemWithKey(iCodehTab,i))) continue ;
1280 if (SKIP_IC(ic)) continue;
1281 if (!IS_ASSIGN_ICODE(ic)) continue ;
1283 /* if result is assigned to registers */
1284 if (IS_SYMOP(IC_RESULT(ic)) &&
1285 bitVectBitValue(_G.totRegAssigned,OP_SYMBOL(IC_RESULT(ic))->key)) {
1286 pdone += positionRegs(sym,OP_SYMBOL(IC_RESULT(ic)));
1288 if (pdone > 1) break;
1291 /* had to position more than once GIVE UP */
1293 /* UNDO all the changes we made to try this */
1295 for (i=0; i < sym->nRegs ; i++ ) {
1296 sym->regs[i] = NULL;
1299 D(D_FILL_GAPS,("Fill Gap gave up due to positioning for %s in function %s\n",sym->name, currFunc ? currFunc->name : "UNKNOWN"));
1302 D(D_FILL_GAPS,("FILLED GAP for %s in function %s\n",sym->name, currFunc ? currFunc->name : "UNKNOWN"));
1303 _G.totRegAssigned = bitVectSetBit(_G.totRegAssigned,sym->key);
1304 sym->isspilt = sym->spillA = 0 ;
1305 sym->usl.spillLoc->allocreq--;
1310 /*-----------------------------------------------------------------*/
1311 /* rUmaskForOp :- returns register mask for an operand */
1312 /*-----------------------------------------------------------------*/
1314 rUmaskForOp (operand * op)
1320 /* only temporaries are assigned registers */
1324 sym = OP_SYMBOL (op);
1326 /* if spilt or no registers assigned to it
1328 if (sym->isspilt || !sym->nRegs)
1331 rumask = newBitVect (_G.nRegs);
1333 for (j = 0; j < sym->nRegs; j++)
1335 rumask = bitVectSetBit (rumask, sym->regs[j]->rIdx);
1342 z80_rUmaskForOp (operand * op)
1344 return rUmaskForOp (op);
1347 /** Returns bit vector of registers used in iCode.
1350 regsUsedIniCode (iCode * ic)
1352 bitVect *rmask = newBitVect (_G.nRegs);
1354 /* do the special cases first */
1357 rmask = bitVectUnion (rmask,
1358 rUmaskForOp (IC_COND (ic)));
1362 /* for the jumptable */
1363 if (ic->op == JUMPTABLE)
1365 rmask = bitVectUnion (rmask,
1366 rUmaskForOp (IC_JTCOND (ic)));
1371 /* of all other cases */
1373 rmask = bitVectUnion (rmask,
1374 rUmaskForOp (IC_LEFT (ic)));
1378 rmask = bitVectUnion (rmask,
1379 rUmaskForOp (IC_RIGHT (ic)));
1382 rmask = bitVectUnion (rmask,
1383 rUmaskForOp (IC_RESULT (ic)));
1389 /** For each instruction will determine the regsUsed.
1392 createRegMask (eBBlock ** ebbs, int count)
1396 /* for all blocks */
1397 for (i = 0; i < count; i++)
1401 if (ebbs[i]->noPath &&
1402 (ebbs[i]->entryLabel != entryLabel &&
1403 ebbs[i]->entryLabel != returnLabel))
1406 /* for all instructions */
1407 for (ic = ebbs[i]->sch; ic; ic = ic->next)
1412 if (SKIP_IC2 (ic) || !ic->rlive)
1415 /* first mark the registers used in this
1417 ic->rUsed = regsUsedIniCode (ic);
1418 _G.funcrUsed = bitVectUnion (_G.funcrUsed, ic->rUsed);
1420 /* now create the register mask for those
1421 registers that are in use : this is a
1422 super set of ic->rUsed */
1423 ic->rMask = newBitVect (_G.nRegs + 1);
1425 /* for all live Ranges alive at this point */
1426 for (j = 1; j < ic->rlive->size; j++)
1431 /* if not alive then continue */
1432 if (!bitVectBitValue (ic->rlive, j))
1435 /* find the live range we are interested in */
1436 if (!(sym = hTabItemWithKey (liveRanges, j)))
1438 werror (E_INTERNAL_ERROR, __FILE__, __LINE__,
1439 "createRegMask cannot find live range");
1443 /* if no register assigned to it */
1444 if (!sym->nRegs || sym->isspilt)
1447 /* for all the registers allocated to it */
1448 for (k = 0; k < sym->nRegs; k++)
1451 bitVectSetBit (ic->rMask, sym->regs[k]->rIdx);
1457 /** Returns the rematerialized string for a remat var.
1460 rematStr (symbol * sym)
1463 iCode *ic = sym->rematiCode;
1468 /* if plus or minus print the right hand side */
1469 if (ic->op == '+' || ic->op == '-')
1471 sprintf (s, "0x%04x %c ", (int) operandLitValue (IC_RIGHT (ic)),
1474 ic = OP_SYMBOL (IC_LEFT (ic))->rematiCode;
1477 /* we reached the end */
1478 sprintf (s, "%s", OP_SYMBOL (IC_LEFT (ic))->rname);
1485 /*-----------------------------------------------------------------*/
1486 /* regTypeNum - computes the type & number of registers required */
1487 /*-----------------------------------------------------------------*/
1494 /* for each live range do */
1495 for (sym = hTabFirstItem (liveRanges, &k); sym;
1496 sym = hTabNextItem (liveRanges, &k))
1499 /* if used zero times then no registers needed */
1500 if ((sym->liveTo - sym->liveFrom) == 0)
1503 D (D_ALLOC, ("regTypeNum: loop on sym %p\n", sym));
1505 /* if the live range is a temporary */
1509 /* if the type is marked as a conditional */
1510 if (sym->regType == REG_CND)
1513 /* if used in return only then we don't
1515 if (sym->ruonly || sym->accuse)
1517 if (IS_AGGREGATE (sym->type) || sym->isptr)
1518 sym->type = aggrToPtr (sym->type, FALSE);
1522 /* if not then we require registers */
1523 D (D_ALLOC, ("regTypeNum: isagg %u nRegs %u type %p\n", IS_AGGREGATE (sym->type) || sym->isptr, sym->nRegs, sym->type));
1524 sym->nRegs = ((IS_AGGREGATE (sym->type) || sym->isptr) ?
1525 getSize (sym->type = aggrToPtr (sym->type, FALSE)) :
1526 getSize (sym->type));
1527 D (D_ALLOC, ("regTypeNum: setting nRegs of %s (%p) to %u\n", sym->name, sym, sym->nRegs));
1529 D (D_ALLOC, ("regTypeNum: setup to assign regs sym %p\n", sym));
1533 fprintf (stderr, "allocated more than 4 or 0 registers for type ");
1534 printTypeChain (sym->type, stderr);
1535 fprintf (stderr, "\n");
1538 /* determine the type of register required */
1539 /* Always general purpose */
1540 sym->regType = REG_GPR;
1545 /* for the first run we don't provide */
1546 /* registers for true symbols we will */
1547 /* see how things go */
1548 D (D_ALLOC, ("regTypeNum: #2 setting num of %p to 0\n", sym));
1555 /** Mark all registers as free.
1562 D (D_ALLOC, ("freeAllRegs: running.\n"));
1564 for (i = 0; i < _G.nRegs; i++)
1565 regsZ80[i].isFree = 1;
1568 /*-----------------------------------------------------------------*/
1569 /* deallocStackSpil - this will set the stack pointer back */
1570 /*-----------------------------------------------------------------*/
1571 DEFSETFUNC (deallocStackSpil)
1579 /** Register reduction for assignment.
1582 packRegsForAssign (iCode * ic, eBBlock * ebp)
1586 D (D_ALLOC, ("packRegsForAssign: running on ic %p\n", ic));
1588 if (!IS_ITEMP (IC_RIGHT (ic)) ||
1589 OP_SYMBOL (IC_RIGHT (ic))->isind ||
1590 OP_LIVETO (IC_RIGHT (ic)) > ic->seq)
1595 /* find the definition of iTempNN scanning backwards if we find a
1596 a use of the true symbol in before we find the definition then
1598 for (dic = ic->prev; dic; dic = dic->prev)
1600 /* PENDING: Don't pack across function calls. */
1601 if (dic->op == CALL || dic->op == PCALL)
1610 if (IS_SYMOP (IC_RESULT (dic)) &&
1611 IC_RESULT (dic)->key == IC_RIGHT (ic)->key)
1616 if (IS_SYMOP (IC_RIGHT (dic)) &&
1617 (IC_RIGHT (dic)->key == IC_RESULT (ic)->key ||
1618 IC_RIGHT (dic)->key == IC_RIGHT (ic)->key))
1624 if (IS_SYMOP (IC_LEFT (dic)) &&
1625 (IC_LEFT (dic)->key == IC_RESULT (ic)->key ||
1626 IC_LEFT (dic)->key == IC_RIGHT (ic)->key))
1634 return 0; /* did not find */
1636 /* if the result is on stack or iaccess then it must be
1637 the same atleast one of the operands */
1638 if (OP_SYMBOL (IC_RESULT (ic))->onStack ||
1639 OP_SYMBOL (IC_RESULT (ic))->iaccess)
1641 /* the operation has only one symbol
1642 operator then we can pack */
1643 if ((IC_LEFT (dic) && !IS_SYMOP (IC_LEFT (dic))) ||
1644 (IC_RIGHT (dic) && !IS_SYMOP (IC_RIGHT (dic))))
1647 if (!((IC_LEFT (dic) &&
1648 IC_RESULT (ic)->key == IC_LEFT (dic)->key) ||
1650 IC_RESULT (ic)->key == IC_RIGHT (dic)->key)))
1654 /* found the definition */
1655 /* replace the result with the result of */
1656 /* this assignment and remove this assignment */
1657 bitVectUnSetBit(OP_SYMBOL(IC_RESULT(dic))->defs,dic->key);
1658 IC_RESULT (dic) = IC_RESULT (ic);
1660 if (IS_ITEMP (IC_RESULT (dic)) && OP_SYMBOL (IC_RESULT (dic))->liveFrom > dic->seq)
1662 OP_SYMBOL (IC_RESULT (dic))->liveFrom = dic->seq;
1664 /* delete from liverange table also
1665 delete from all the points inbetween and the new
1667 for (sic = dic; sic != ic; sic = sic->next)
1669 bitVectUnSetBit (sic->rlive, IC_RESULT (ic)->key);
1670 if (IS_ITEMP (IC_RESULT (dic)))
1671 bitVectSetBit (sic->rlive, IC_RESULT (dic)->key);
1674 remiCodeFromeBBlock (ebp, ic);
1675 // PENDING: Check vs mcs51
1676 bitVectUnSetBit(OP_SYMBOL(IC_RESULT(ic))->defs,ic->key);
1677 hTabDeleteItem (&iCodehTab, ic->key, ic, DELETE_ITEM, NULL);
1678 OP_DEFS(IC_RESULT (dic))=bitVectSetBit (OP_DEFS (IC_RESULT (dic)), dic->key);
1682 /** Scanning backwards looks for first assig found.
1685 findAssignToSym (operand * op, iCode * ic)
1689 for (dic = ic->prev; dic; dic = dic->prev)
1692 /* if definition by assignment */
1693 if (dic->op == '=' &&
1694 !POINTER_SET (dic) &&
1695 IC_RESULT (dic)->key == op->key)
1696 /* && IS_TRUE_SYMOP(IC_RIGHT(dic)) */
1699 /* we are interested only if defined in far space */
1700 /* or in stack space in case of + & - */
1702 /* if assigned to a non-symbol then return
1704 if (!IS_SYMOP (IC_RIGHT (dic)))
1707 /* if the symbol is in far space then
1709 if (isOperandInFarSpace (IC_RIGHT (dic)))
1712 /* for + & - operations make sure that
1713 if it is on the stack it is the same
1714 as one of the three operands */
1715 if ((ic->op == '+' || ic->op == '-') &&
1716 OP_SYMBOL (IC_RIGHT (dic))->onStack)
1719 if (IC_RESULT (ic)->key != IC_RIGHT (dic)->key &&
1720 IC_LEFT (ic)->key != IC_RIGHT (dic)->key &&
1721 IC_RIGHT (ic)->key != IC_RIGHT (dic)->key)
1729 /* if we find an usage then we cannot delete it */
1730 if (IC_LEFT (dic) && IC_LEFT (dic)->key == op->key)
1733 if (IC_RIGHT (dic) && IC_RIGHT (dic)->key == op->key)
1736 if (POINTER_SET (dic) && IC_RESULT (dic)->key == op->key)
1740 /* now make sure that the right side of dic
1741 is not defined between ic & dic */
1744 iCode *sic = dic->next;
1746 for (; sic != ic; sic = sic->next)
1747 if (IC_RESULT (sic) &&
1748 IC_RESULT (sic)->key == IC_RIGHT (dic)->key)
1757 #if !DISABLE_PACKREGSFORSUPPORT
1760 /*-----------------------------------------------------------------*/
1761 /* packRegsForSupport :- reduce some registers for support calls */
1762 /*-----------------------------------------------------------------*/
1764 packRegsForSupport (iCode * ic, eBBlock * ebp)
1767 /* for the left & right operand :- look to see if the
1768 left was assigned a true symbol in far space in that
1769 case replace them */
1770 D (D_ALLOC, ("packRegsForSupport: running on ic %p\n", ic));
1772 if (IS_ITEMP (IC_LEFT (ic)) &&
1773 OP_SYMBOL (IC_LEFT (ic))->liveTo <= ic->seq)
1775 iCode *dic = findAssignToSym (IC_LEFT (ic), ic);
1781 /* found it we need to remove it from the
1783 for (sic = dic; sic != ic; sic = sic->next)
1784 bitVectUnSetBit (sic->rlive, IC_LEFT (ic)->key);
1786 IC_LEFT (ic)->operand.symOperand =
1787 IC_RIGHT (dic)->operand.symOperand;
1788 IC_LEFT (ic)->key = IC_RIGHT (dic)->operand.symOperand->key;
1789 remiCodeFromeBBlock (ebp, dic);
1790 bitVectUnSetBit(OP_SYMBOL(IC_RESULT(dic))->defs,dic->key);
1791 hTabDeleteItem (&iCodehTab, dic->key, dic, DELETE_ITEM, NULL);
1792 // PENDING: Check vs mcs51
1796 /* do the same for the right operand */
1799 IS_ITEMP (IC_RIGHT (ic)) &&
1800 OP_SYMBOL (IC_RIGHT (ic))->liveTo <= ic->seq)
1802 iCode *dic = findAssignToSym (IC_RIGHT (ic), ic);
1808 /* found it we need to remove it from the block */
1809 for (sic = dic; sic != ic; sic = sic->next)
1810 bitVectUnSetBit (sic->rlive, IC_RIGHT (ic)->key);
1812 IC_RIGHT (ic)->operand.symOperand =
1813 IC_RIGHT (dic)->operand.symOperand;
1814 IC_RIGHT (ic)->key = IC_RIGHT (dic)->operand.symOperand->key;
1816 remiCodeFromeBBlock (ebp, dic);
1817 bitVectUnSetBit(OP_SYMBOL(IC_RESULT(dic))->defs,dic->key);
1818 hTabDeleteItem (&iCodehTab, dic->key, dic, DELETE_ITEM, NULL);
1819 // PENDING: vs mcs51
1827 #define IS_OP_RUONLY(x) (x && IS_SYMOP(x) && OP_SYMBOL(x)->ruonly)
1829 /** Will reduce some registers for single use.
1832 packRegsForOneuse (iCode * ic, operand * op, eBBlock * ebp)
1838 D (D_ALLOC, ("packRegsForOneUse: running on ic %p\n", ic));
1840 /* if returning a literal then do nothing */
1844 /* only upto 2 bytes since we cannot predict
1845 the usage of b, & acc */
1846 if (getSize (operandType (op)) > 2)
1849 if (ic->op != RETURN &&
1853 /* this routine will mark the a symbol as used in one
1854 instruction use only && if the defintion is local
1855 (ie. within the basic block) && has only one definition &&
1856 that definiion is either a return value from a
1857 function or does not contain any variables in
1859 uses = bitVectCopy (OP_USES (op));
1860 bitVectUnSetBit (uses, ic->key); /* take away this iCode */
1861 if (!bitVectIsZero (uses)) /* has other uses */
1864 /* if it has only one defintion */
1865 if (bitVectnBitsOn (OP_DEFS (op)) > 1)
1866 return NULL; /* has more than one definition */
1868 /* get the that definition */
1870 hTabItemWithKey (iCodehTab,
1871 bitVectFirstBit (OP_DEFS (op)))))
1874 /* found the definition now check if it is local */
1875 if (dic->seq < ebp->fSeq ||
1876 dic->seq > ebp->lSeq)
1877 return NULL; /* non-local */
1879 /* now check if it is the return from a function call */
1880 if (dic->op == CALL || dic->op == PCALL)
1882 if (ic->op != SEND && ic->op != RETURN &&
1883 !POINTER_SET(ic) && !POINTER_GET(ic))
1885 OP_SYMBOL (op)->ruonly = 1;
1891 /* otherwise check that the definition does
1892 not contain any symbols in far space */
1893 if (isOperandInFarSpace (IC_LEFT (dic)) ||
1894 isOperandInFarSpace (IC_RIGHT (dic)) ||
1895 IS_OP_RUONLY (IC_LEFT (ic)) ||
1896 IS_OP_RUONLY (IC_RIGHT (ic)))
1901 /* if pointer set then make sure the pointer is one byte */
1902 if (POINTER_SET (dic))
1905 if (POINTER_GET (dic))
1910 /* also make sure the intervenening instructions
1911 don't have any thing in far space */
1912 for (dic = dic->next; dic && dic != ic; dic = dic->next)
1914 /* if there is an intervening function call then no */
1915 if (dic->op == CALL || dic->op == PCALL)
1917 /* if pointer set then make sure the pointer
1919 if (POINTER_SET (dic))
1922 if (POINTER_GET (dic))
1925 /* if address of & the result is remat the okay */
1926 if (dic->op == ADDRESS_OF &&
1927 OP_SYMBOL (IC_RESULT (dic))->remat)
1930 /* if left or right or result is in far space */
1931 if (isOperandInFarSpace (IC_LEFT (dic)) ||
1932 isOperandInFarSpace (IC_RIGHT (dic)) ||
1933 isOperandInFarSpace (IC_RESULT (dic)) ||
1934 IS_OP_RUONLY (IC_LEFT (dic)) ||
1935 IS_OP_RUONLY (IC_RIGHT (dic)) ||
1936 IS_OP_RUONLY (IC_RESULT (dic)))
1942 OP_SYMBOL (op)->ruonly = 1;
1946 /*-----------------------------------------------------------------*/
1947 /* isBitwiseOptimizable - requirements of JEAN LOUIS VERN */
1948 /*-----------------------------------------------------------------*/
1950 isBitwiseOptimizable (iCode * ic)
1952 sym_link *rtype = getSpec (operandType (IC_RIGHT (ic)));
1954 /* bitwise operations are considered optimizable
1955 under the following conditions (Jean-Louis VERN)
1967 if (IS_LITERAL (rtype))
1973 Certian assignments involving pointers can be temporarly stored
1984 #if !DISABLE_PACKREGSFORACCUSE
1987 /** Pack registers for acc use.
1988 When the result of this operation is small and short lived it may
1989 be able to be stored in the accumelator.
1992 packRegsForAccUse (iCode * ic)
1996 /* if this is an aggregate, e.g. a one byte char array */
1997 if (IS_AGGREGATE(operandType(IC_RESULT(ic)))) {
2001 /* if + or - then it has to be one byte result */
2002 if ((ic->op == '+' || ic->op == '-')
2003 && getSize (operandType (IC_RESULT (ic))) > 1)
2006 /* if shift operation make sure right side is not a literal */
2007 if (ic->op == RIGHT_OP &&
2008 (isOperandLiteral (IC_RIGHT (ic)) ||
2009 getSize (operandType (IC_RESULT (ic))) > 1))
2012 if (ic->op == LEFT_OP &&
2013 (isOperandLiteral (IC_RIGHT (ic)) ||
2014 getSize (operandType (IC_RESULT (ic))) > 1))
2017 /* has only one definition */
2018 if (bitVectnBitsOn (OP_DEFS (IC_RESULT (ic))) > 1)
2021 /* has only one use */
2022 if (bitVectnBitsOn (OP_USES (IC_RESULT (ic))) > 1)
2025 /* and the usage immediately follows this iCode */
2026 if (!(uic = hTabItemWithKey (iCodehTab,
2027 bitVectFirstBit (OP_USES (IC_RESULT (ic))))))
2030 if (ic->next != uic)
2033 /* if it is a conditional branch then we definitely can */
2037 if (uic->op == JUMPTABLE)
2041 /* if the usage is not is an assignment or an
2042 arithmetic / bitwise / shift operation then not */
2043 if (POINTER_SET (uic) &&
2044 getSize (aggrToPtr (operandType (IC_RESULT (uic)), FALSE)) > 1)
2048 if (uic->op != '=' &&
2049 !IS_ARITHMETIC_OP (uic) &&
2050 !IS_BITWISE_OP (uic) &&
2051 uic->op != LEFT_OP &&
2052 uic->op != RIGHT_OP)
2055 /* if used in ^ operation then make sure right is not a
2057 if (uic->op == '^' && isOperandLiteral (IC_RIGHT (uic)))
2060 /* if shift operation make sure right side is not a literal */
2061 if (uic->op == RIGHT_OP &&
2062 (isOperandLiteral (IC_RIGHT (uic)) ||
2063 getSize (operandType (IC_RESULT (uic))) > 1))
2066 if (uic->op == LEFT_OP &&
2067 (isOperandLiteral (IC_RIGHT (uic)) ||
2068 getSize (operandType (IC_RESULT (uic))) > 1))
2072 /* make sure that the result of this icode is not on the
2073 stack, since acc is used to compute stack offset */
2074 if (IS_TRUE_SYMOP (IC_RESULT (uic)) &&
2075 OP_SYMBOL (IC_RESULT (uic))->onStack)
2080 /* if either one of them in far space then we cannot */
2081 if ((IS_TRUE_SYMOP (IC_LEFT (uic)) &&
2082 isOperandInFarSpace (IC_LEFT (uic))) ||
2083 (IS_TRUE_SYMOP (IC_RIGHT (uic)) &&
2084 isOperandInFarSpace (IC_RIGHT (uic))))
2088 /* if the usage has only one operand then we can */
2089 if (IC_LEFT (uic) == NULL ||
2090 IC_RIGHT (uic) == NULL)
2093 /* make sure this is on the left side if not
2094 a '+' since '+' is commutative */
2095 if (ic->op != '+' &&
2096 IC_LEFT (uic)->key != IC_RESULT (ic)->key)
2099 // See mcs51 ralloc for reasoning
2101 /* if one of them is a literal then we can */
2102 if ((IC_LEFT (uic) && IS_OP_LITERAL (IC_LEFT (uic))) ||
2103 (IC_RIGHT (uic) && IS_OP_LITERAL (IC_RIGHT (uic))))
2110 /** This is confusing :) Guess for now */
2111 if (IC_LEFT (uic)->key == IC_RESULT (ic)->key &&
2112 (IS_ITEMP (IC_RIGHT (uic)) ||
2113 (IS_TRUE_SYMOP (IC_RIGHT (uic)))))
2116 if (IC_RIGHT (uic)->key == IC_RESULT (ic)->key &&
2117 (IS_ITEMP (IC_LEFT (uic)) ||
2118 (IS_TRUE_SYMOP (IC_LEFT (uic)))))
2122 OP_SYMBOL (IC_RESULT (ic))->accuse = ACCUSE_A;
2127 packRegsForHLUse (iCode * ic)
2131 /* PENDING: Could do IFX */
2137 /* has only one definition */
2138 if (bitVectnBitsOn (OP_DEFS (IC_RESULT (ic))) > 1)
2140 D (D_HLUSE, (" + Dropping as has more than one def\n"));
2144 /* has only one use */
2145 if (bitVectnBitsOn (OP_USES (IC_RESULT (ic))) > 1)
2147 D (D_HLUSE, (" + Dropping as has more than one use\n"));
2151 /* and the usage immediately follows this iCode */
2152 if (!(uic = hTabItemWithKey (iCodehTab,
2153 bitVectFirstBit (OP_USES (IC_RESULT (ic))))))
2155 D (D_HLUSE, (" + Dropping as usage isn't in this block\n"));
2159 if (ic->next != uic)
2161 D (D_HLUSE, (" + Dropping as usage doesn't follow this\n"));
2170 if (getSize (operandType (IC_RESULT (ic))) != 2 ||
2171 (IC_LEFT(uic) && getSize (operandType (IC_LEFT (uic))) != 2) ||
2172 (IC_RIGHT(uic) && getSize (operandType (IC_RIGHT (uic))) != 2))
2174 D (D_HLUSE, (" + Dropping as the result size is not 2\n"));
2180 if (ic->op == CAST && uic->op == IPUSH)
2182 if (ic->op == ADDRESS_OF && uic->op == IPUSH)
2184 if (ic->op == ADDRESS_OF && POINTER_GET (uic) && IS_ITEMP( IC_RESULT (uic)))
2186 if (ic->op == CALL && ic->parmBytes == 0 && (uic->op == '-' || uic->op == '+'))
2191 /* Case of assign a constant to offset in a static array. */
2192 if (ic->op == '+' && IS_VALOP (IC_RIGHT (ic)))
2194 if (uic->op == '=' && POINTER_SET (uic))
2198 else if (uic->op == IPUSH && getSize (operandType (IC_LEFT (uic))) == 2)
2205 D (D_HLUSE, (" + Dropping as it's a bad op\n"));
2208 OP_SYMBOL (IC_RESULT (ic))->accuse = ACCUSE_SCRATCH;
2212 packRegsForHLUse3 (iCode * lic, operand * op, eBBlock * ebp)
2217 bool isFirst = TRUE;
2219 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));
2223 if ( OP_SYMBOL(op)->accuse)
2228 if (OP_SYMBOL(op)->remat)
2233 /* Only defined once */
2234 if (bitVectnBitsOn (OP_DEFS (op)) > 1)
2237 if (getSize (operandType (op)) > 2)
2240 /* And this is the definition */
2241 if (bitVectFirstBit (OP_DEFS (op)) != lic->key)
2244 /* first check if any overlapping liverange has already been
2246 if (OP_SYMBOL(op)->clashes)
2248 for (i = 0 ; i < OP_SYMBOL(op)->clashes->size ; i++ )
2250 if (bitVectBitValue(OP_SYMBOL(op)->clashes,i))
2252 sym = hTabItemWithKey(liveRanges,i);
2253 if (sym->accuse == ACCUSE_SCRATCH)
2261 /* Nothing else that clashes with this is using the scratch
2262 register. Scan through all of the intermediate instructions and
2263 see if any of them could nuke HL.
2265 dic = ic = hTabFirstItemWK(iCodeSeqhTab,OP_SYMBOL(op)->liveFrom);
2267 for (; ic && ic->seq <= OP_SYMBOL(op)->liveTo;
2268 ic = hTabNextItem(iCodeSeqhTab, &key))
2272 D (D_PACK_HLUSE3, ("(On %p: op: %u next: %p)\n", ic, ic->op, ic->next));
2277 if (ic->op == ADDRESS_OF)
2279 if (POINTER_GET (ic))
2281 if (ic->op == '=' && !POINTER_SET(ic))
2285 if (IC_RESULT(ic) && IS_SYMOP(IC_RESULT(ic))
2286 && isOperandInDirSpace (IC_RESULT (ic)))
2289 if (IC_LEFT(ic) && IS_SYMOP(IC_LEFT(ic))
2290 && isOperandInDirSpace (IC_LEFT (ic)))
2293 if (IC_RIGHT(ic) && IS_SYMOP(IC_RIGHT(ic))
2294 && isOperandInDirSpace (IC_RIGHT (ic)))
2297 /* Handle the non left/right/result ones first */
2300 if (ic->op == JUMPTABLE)
2309 if (ic->op == IPUSH && isOperandEqual (op, IC_LEFT (ic)))
2312 if (ic->op == SEND && isOperandEqual (op, IC_LEFT (ic)))
2315 if (ic->op == CALL && isOperandEqual (op, IC_RESULT (ic)))
2318 if (ic->op == LEFT_OP && isOperandLiteral (IC_RIGHT (ic)))
2321 if ((ic->op == '=' && !POINTER_SET(ic)) ||
2322 ic->op == UNARYMINUS ||
2331 if (ic->op == '*' && isOperandEqual (op, IC_LEFT (ic)))
2334 if (POINTER_SET (ic) && isOperandEqual (op, IC_RESULT (ic)))
2337 if (POINTER_GET (ic) && isOperandEqual (op, IC_LEFT (ic)))
2340 if (IS_VALOP (IC_RIGHT (ic)) &&
2347 /* By default give up */
2351 D (D_PACK_HLUSE3, ("Succeeded!\n"))
2353 OP_SYMBOL (op)->accuse = ACCUSE_SCRATCH;
2358 packRegsForIYUse (iCode * lic, operand * op, eBBlock * ebp)
2365 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));
2369 if ( OP_SYMBOL(op)->accuse)
2374 if (OP_SYMBOL(op)->remat)
2379 /* Only defined once */
2380 if (bitVectnBitsOn (OP_DEFS (op)) > 1)
2383 /* And this is the definition */
2384 if (bitVectFirstBit (OP_DEFS (op)) != lic->key)
2387 /* first check if any overlapping liverange has already been
2389 if (OP_SYMBOL(op)->clashes)
2391 for (i = 0 ; i < OP_SYMBOL(op)->clashes->size ; i++ )
2393 if (bitVectBitValue(OP_SYMBOL(op)->clashes,i))
2395 sym = hTabItemWithKey(liveRanges,i);
2396 if (sym->accuse == ACCUSE_IY)
2404 /* Only a few instructions can load into IY */
2410 if (getSize (operandType (op)) != 2)
2412 D (D_ACCUSE2, (" + Dropping as operation has size is too big\n"));
2416 /* Nothing else that clashes with this is using the scratch
2417 register. Scan through all of the intermediate instructions and
2418 see if any of them could nuke HL.
2420 dic = ic = hTabFirstItemWK(iCodeSeqhTab,OP_SYMBOL(op)->liveFrom);
2423 for (; ic && ic->seq <= OP_SYMBOL(op)->liveTo;
2424 ic = hTabNextItem(iCodeSeqhTab,&key))
2429 if (ic->op == PCALL ||
2438 /* Be pessamistic. */
2442 D (D_PACK_IY, (" op: %u uses %u result: %d left: %d right: %d\n", ic->op, bitVectBitValue(uses, ic->key),
2443 IC_RESULT(ic) && IS_SYMOP(IC_RESULT(ic)) ? isOperandInDirSpace(IC_RESULT(ic)) : -1,
2444 IC_LEFT(ic) && IS_SYMOP(IC_LEFT(ic)) ? isOperandInDirSpace(IC_LEFT(ic)) : -1,
2445 IC_RIGHT(ic) && IS_SYMOP(IC_RIGHT(ic)) ? isOperandInDirSpace(IC_RIGHT(ic)) : -1
2448 if (IC_RESULT(ic) && IS_SYMOP(IC_RESULT(ic)) &&
2449 isOperandInDirSpace(IC_RESULT(ic)))
2452 if (IC_RIGHT(ic) && IS_SYMOP(IC_RIGHT(ic)) &&
2453 isOperandInDirSpace(IC_RIGHT(ic)))
2456 if (IC_LEFT(ic) && IS_SYMOP(IC_LEFT(ic)) &&
2457 isOperandInDirSpace(IC_LEFT(ic)))
2460 /* Only certain rules will work against IY. Check if this iCode uses
2462 if (bitVectBitValue(uses, ic->key) != 0)
2464 if (ic->op == '=' &&
2465 isOperandEqual(IC_RESULT(ic), op))
2468 if (ic->op == GET_VALUE_AT_ADDRESS &&
2469 isOperandEqual(IC_LEFT(ic), op))
2472 if (isOperandEqual(IC_RESULT(ic), IC_LEFT(ic)) == FALSE)
2475 if (IC_RIGHT (ic) && IS_VALOP (IC_RIGHT (ic)))
2477 if (ic->op == '+' ||
2480 /* Only works if the constant is small */
2481 if (operandLitValue (IC_RIGHT (ic)) < 4)
2490 /* This iCode doesn't use the sym. See if this iCode preserves IY.
2495 /* By default give up */
2499 D (D_PACK_IY, ("Succeeded IY!\n"));
2501 OP_SYMBOL (op)->accuse = ACCUSE_IY;
2505 /** Returns TRUE if this operation can use acc and if it preserves the value.
2508 opPreservesA (iCode * uic)
2512 /* If we've gotten this far then the thing to compare must be
2513 small enough and must be in A.
2518 if (uic->op == JUMPTABLE)
2520 D (D_ACCUSE2, (" + Dropping as operation is a Jumptable\n"));
2524 /* A pointer assign preserves A if A is the left value. */
2525 if (uic->op == '=' && POINTER_SET (uic))
2530 /* if the usage has only one operand then we can */
2531 /* PENDING: check */
2532 if (IC_LEFT (uic) == NULL ||
2533 IC_RIGHT (uic) == NULL)
2535 D (D_ACCUSE2, (" + Dropping as operation has only one operand\n"));
2539 /* PENDING: check this rule */
2540 if (getSize (operandType (IC_RESULT (uic))) > 1)
2542 D (D_ACCUSE2, (" + Dropping as operation has size is too big\n"));
2547 /* Disabled all of the old rules as they weren't verified and have
2548 caused at least one problem.
2553 /** Returns true if this operand preserves the value of A.
2556 opIgnoresA (iCode * ic, iCode * uic)
2558 /* A increment of an iTemp by a constant is OK. */
2559 if ( uic->op == '+' &&
2560 IS_ITEMP (IC_LEFT (uic)) &&
2561 IS_ITEMP (IC_RESULT (uic)) &&
2562 IS_OP_LITERAL (IC_RIGHT (uic)))
2564 unsigned int icount = (unsigned int) floatFromVal (IC_RIGHT (uic)->operand.valOperand);
2566 /* Being an ITEMP means that we're already a symbol. */
2568 IC_RESULT (uic)->operand.symOperand->key == IC_LEFT (uic)->operand.symOperand->key
2574 else if (uic->op == '=' && !POINTER_SET (uic))
2576 /* If they are equal and get optimised out then things are OK. */
2577 if (isOperandEqual (IC_RESULT (uic), IC_RIGHT (uic)))
2579 /* Straight assign is OK. */
2588 /* Some optimisation cases:
2600 ; genAssign (pointer)
2604 want to optimise down to:
2610 So genPointer get is OK
2611 genPlus where the right is constant, left is iTemp, and result is same as left
2612 genAssign (pointer) is OK
2623 ; genAssign (pointer)
2624 ; AOP_STK for _strcpy_to_1_1
2629 want to optimise down to:
2635 So genIfx where IC_COND has size of 1 and is a constant.
2638 /** Pack registers for acc use.
2639 When the result of this operation is small and short lived it may
2640 be able to be stored in the accumulator.
2642 Note that the 'A preserving' list is currently emperical :)
2645 packRegsForAccUse2 (iCode * ic)
2649 D (D_ACCUSE2, ("packRegsForAccUse2: running on ic %p line %u\n", ic, ic->lineno));
2653 /* Filter out all but those 'good' commands */
2655 !POINTER_GET (ic) &&
2658 !IS_BITWISE_OP (ic) &&
2664 ic->op != GETHBIT &&
2667 D (D_ACCUSE2, (" + Dropping as not a 'good' source command\n"));
2671 /* if + or - then it has to be one byte result.
2674 if ((ic->op == '+' || ic->op == '-')
2675 && getSize (operandType (IC_RESULT (ic))) > 1)
2677 D (D_ACCUSE2, (" + Dropping as it's a big + or -\n"));
2681 /* has only one definition */
2682 if (bitVectnBitsOn (OP_DEFS (IC_RESULT (ic))) > 1)
2684 D (D_ACCUSE2, (" + Dropping as it has more than one definition\n"));
2688 /* Right. We may be able to propagate it through if:
2689 For each in the chain of uses the intermediate is OK.
2691 /* Get next with 'uses result' bit on
2692 If this->next == next
2693 Validate use of next
2694 If OK, increase count
2696 /* and the usage immediately follows this iCode */
2697 if (!(uic = hTabItemWithKey (iCodehTab,
2698 bitVectFirstBit (OP_USES (IC_RESULT (ic))))))
2700 D (D_ACCUSE2, (" + Dropping as usage does not follow first\n"));
2705 /* Create a copy of the OP_USES bit vect */
2706 bitVect *uses = bitVectCopy (OP_USES (IC_RESULT (ic)));
2708 iCode *scan = ic, *next;
2712 setBit = bitVectFirstBit (uses);
2713 next = hTabItemWithKey (iCodehTab, setBit);
2714 if (scan->next == next)
2716 D (D_ACCUSE2_VERBOSE, (" ! Is next in line\n"));
2718 bitVectUnSetBit (uses, setBit);
2719 /* Still contigous. */
2720 if (!opPreservesA (next))
2722 D (D_ACCUSE2, (" + Dropping as operation doesn't preserve A\n"));
2725 D (D_ACCUSE2_VERBOSE, (" ! Preserves A, so continue scanning\n"));
2728 else if (scan->next == NULL && bitVectnBitsOn (uses) == 1 && next != NULL)
2730 if (next->prev == NULL)
2732 if (!opPreservesA (next))
2734 D (D_ACCUSE2, (" + Dropping as operation doesn't preserve A #2\n"));
2737 bitVectUnSetBit (uses, setBit);
2742 D (D_ACCUSE2, (" + Dropping as last in list and next doesn't start a block\n"));
2746 else if (scan->next == NULL)
2748 D (D_ACCUSE2, (" + Dropping as hit the end of the list\n"));
2749 D (D_ACCUSE2, (" + Next in htab: %p\n", next));
2754 if (opIgnoresA (ic, scan->next))
2758 D (D_ACCUSE2_VERBOSE, (" ! Op ignores A, so continue scanning\n"));
2762 D (D_ACCUSE2, (" + Dropping as parts are not consecuitive and intermediate might use A\n"));
2767 while (!bitVectIsZero (uses));
2769 OP_SYMBOL (IC_RESULT (ic))->accuse = ACCUSE_A;
2774 /** Does some transformations to reduce register pressure.
2777 packRegisters (eBBlock * ebp)
2782 D (D_ALLOC, ("packRegisters: entered.\n"));
2784 while (1 && !DISABLE_PACK_ASSIGN)
2787 /* look for assignments of the form */
2788 /* iTempNN = TRueSym (someoperation) SomeOperand */
2790 /* TrueSym := iTempNN:1 */
2791 for (ic = ebp->sch; ic; ic = ic->next)
2793 /* find assignment of the form TrueSym := iTempNN:1 */
2794 if (ic->op == '=' && !POINTER_SET (ic))
2795 change += packRegsForAssign (ic, ebp);
2801 for (ic = ebp->sch; ic; ic = ic->next)
2803 /* Safe: address of a true sym is always constant. */
2804 /* if this is an itemp & result of a address of a true sym
2805 then mark this as rematerialisable */
2806 D (D_ALLOC, ("packRegisters: looping on ic %p\n", ic));
2808 if (ic->op == ADDRESS_OF &&
2809 IS_ITEMP (IC_RESULT (ic)) &&
2810 IS_TRUE_SYMOP (IC_LEFT (ic)) &&
2811 bitVectnBitsOn (OP_DEFS (IC_RESULT (ic))) == 1 &&
2812 !OP_SYMBOL (IC_LEFT (ic))->onStack)
2815 OP_SYMBOL (IC_RESULT (ic))->remat = 1;
2816 OP_SYMBOL (IC_RESULT (ic))->rematiCode = ic;
2817 OP_SYMBOL (IC_RESULT (ic))->usl.spillLoc = NULL;
2820 /* Safe: just propagates the remat flag */
2821 /* if straight assignment then carry remat flag if this is the
2823 if (ic->op == '=' &&
2824 !POINTER_SET (ic) &&
2825 IS_SYMOP (IC_RIGHT (ic)) &&
2826 OP_SYMBOL (IC_RIGHT (ic))->remat &&
2827 bitVectnBitsOn (OP_SYMBOL (IC_RESULT (ic))->defs) <= 1)
2830 OP_SYMBOL (IC_RESULT (ic))->remat =
2831 OP_SYMBOL (IC_RIGHT (ic))->remat;
2832 OP_SYMBOL (IC_RESULT (ic))->rematiCode =
2833 OP_SYMBOL (IC_RIGHT (ic))->rematiCode;
2836 /* if the condition of an if instruction is defined in the
2837 previous instruction then mark the itemp as a conditional */
2838 if ((IS_CONDITIONAL (ic) ||
2839 ((ic->op == BITWISEAND ||
2842 isBitwiseOptimizable (ic))) &&
2843 ic->next && ic->next->op == IFX &&
2844 bitVectnBitsOn (OP_USES(IC_RESULT(ic)))==1 &&
2845 isOperandEqual (IC_RESULT (ic), IC_COND (ic->next)) &&
2846 OP_SYMBOL (IC_RESULT (ic))->liveTo <= ic->next->seq)
2849 OP_SYMBOL (IC_RESULT (ic))->regType = REG_CND;
2854 /* reduce for support function calls */
2855 if (ic->supportRtn || ic->op == '+' || ic->op == '-')
2856 packRegsForSupport (ic, ebp);
2859 /* some cases the redundant moves can
2860 can be eliminated for return statements */
2861 if (ic->op == RETURN || ic->op == SEND)
2863 packRegsForOneuse (ic, IC_LEFT (ic), ebp);
2866 /* if pointer set & left has a size more than
2867 one and right is not in far space */
2868 if (!DISABLE_PACK_ONE_USE &&
2870 /* MLH: no such thing.
2871 !isOperandInFarSpace(IC_RIGHT(ic)) && */
2872 !OP_SYMBOL (IC_RESULT (ic))->remat &&
2873 !IS_OP_RUONLY (IC_RIGHT (ic)) &&
2874 getSize (aggrToPtr (operandType (IC_RESULT (ic)), FALSE)) > 1)
2877 packRegsForOneuse (ic, IC_RESULT (ic), ebp);
2880 /* if pointer get */
2881 if (!DISABLE_PACK_ONE_USE &&
2883 IS_SYMOP (IC_LEFT (ic)) &&
2884 /* MLH: dont have far space
2885 !isOperandInFarSpace(IC_RESULT(ic))&& */
2886 !OP_SYMBOL (IC_LEFT (ic))->remat &&
2887 !IS_OP_RUONLY (IC_RESULT (ic)) &&
2888 getSize (aggrToPtr (operandType (IC_LEFT (ic)), FALSE)) > 1)
2891 packRegsForOneuse (ic, IC_LEFT (ic), ebp);
2894 /* pack registers for accumulator use, when the result of an
2895 arithmetic or bit wise operation has only one use, that use is
2896 immediately following the defintion and the using iCode has
2897 only one operand or has two operands but one is literal & the
2898 result of that operation is not on stack then we can leave the
2899 result of this operation in acc:b combination */
2901 if (!DISABLE_PACK_HL && IS_ITEMP (IC_RESULT (ic)))
2907 packRegsForHLUse (ic);
2911 packRegsForHLUse3 (ic, IC_RESULT (ic), ebp);
2915 if (!DISABLE_PACK_IY && IS_ITEMP (IC_RESULT (ic)) && IS_Z80)
2917 packRegsForIYUse (ic, IC_RESULT (ic), ebp);
2920 if (!DISABLE_PACK_ACC && IS_ITEMP (IC_RESULT (ic)) &&
2921 getSize (operandType (IC_RESULT (ic))) == 1)
2923 packRegsForAccUse2 (ic);
2928 /** Joins together two byte constant pushes into one word push.
2931 joinPushes (iCode *lic)
2935 for (ic = lic; ic; ic = ic->next)
2942 /* Anything past this? */
2947 /* This and the next pushes? */
2948 if (ic->op != IPUSH || uic->op != IPUSH)
2952 /* Both literals? */
2953 if ( !IS_OP_LITERAL (IC_LEFT (ic)) || !IS_OP_LITERAL (IC_LEFT (uic)))
2957 /* Both characters? */
2958 if ( getSize (operandType (IC_LEFT (ic))) != 1 || getSize (operandType (IC_LEFT (uic))) != 1)
2962 /* Pull out the values, make a new type, and create the new iCode for it.
2964 first = (int)operandLitValue ( IC_LEFT (ic));
2965 second = (int)operandLitValue ( IC_LEFT (uic));
2967 sprintf (buffer, "%uu", ((first << 8) | (second & 0xFF)) & 0xFFFFU);
2968 val = constVal (buffer);
2969 SPEC_NOUN (val->type) = V_INT;
2970 IC_LEFT (ic)->operand.valOperand = val;
2972 /* Now remove the second one from the list. */
2973 ic->next = uic->next;
2976 /* Patch up the reverse link */
2977 uic->next->prev = ic;
2984 /*-----------------------------------------------------------------*/
2985 /* assignRegisters - assigns registers to each live range as need */
2986 /*-----------------------------------------------------------------*/
2988 z80_assignRegisters (eBBlock ** ebbs, int count)
2993 D (D_ALLOC, ("\n-> z80_assignRegisters: entered.\n"));
2995 setToNull ((void *) &_G.funcrUsed);
2996 setToNull ((void *) &_G.totRegAssigned);
2997 _G.stackExtend = _G.dataExtend = 0;
3001 /* DE is required for the code gen. */
3002 _G.nRegs = GBZ80_MAX_REGS;
3003 regsZ80 = _gbz80_regs;
3007 _G.nRegs = Z80_MAX_REGS;
3008 regsZ80 = _z80_regs;
3011 /* change assignments this will remove some
3012 live ranges reducing some register pressure */
3013 for (i = 0; i < count; i++)
3014 packRegisters (ebbs[i]);
3016 if (options.dump_pack)
3017 dumpEbbsToFileExt (DUMP_PACK, ebbs, count);
3019 /* first determine for each live range the number of
3020 registers & the type of registers required for each */
3023 /* and serially allocate registers */
3024 serialRegAssign (ebbs, count);
3029 /* if stack was extended then tell the user */
3032 /* werror(W_TOOMANY_SPILS,"stack", */
3033 /* _G.stackExtend,currFunc->name,""); */
3039 /* werror(W_TOOMANY_SPILS,"data space", */
3040 /* _G.dataExtend,currFunc->name,""); */
3044 if (options.dump_rassgn) {
3045 dumpEbbsToFileExt (DUMP_RASSGN, ebbs, count);
3046 dumpLiveRanges (DUMP_LRANGE, liveRanges);
3049 /* after that create the register mask
3050 for each of the instruction */
3051 createRegMask (ebbs, count);
3053 /* now get back the chain */
3054 ic = iCodeLabelOptimize (iCodeFromeBBlock (ebbs, count));
3056 ic = joinPushes (ic);
3058 /* redo that offsets for stacked automatic variables */
3059 redoStackOffsets ();
3063 /* free up any stackSpil locations allocated */
3064 applyToSet (_G.stackSpil, deallocStackSpil);
3066 setToNull ((void *) &_G.stackSpil);
3067 setToNull ((void *) &_G.spiltSet);
3068 /* mark all registers as free */