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)
768 D (D_ALLOC, ("getRegGpr: on ic %p\n", ic));
770 /* try for gpr type */
771 if ((reg = allocReg (REG_GPR)))
773 D (D_ALLOC, ("getRegGpr: got a reg.\n"));
777 /* we have to spil */
778 if (!spilSomething (ic, ebp, sym))
780 D (D_ALLOC, ("getRegGpr: have to spill.\n"));
784 /* make sure partially assigned registers aren't reused */
785 for (j=0; j<=sym->nRegs; j++)
787 sym->regs[j]->isFree = 0;
789 /* this looks like an infinite loop but
790 in really selectSpil will abort */
794 static regs *getRegGprNoSpil()
798 /* try for gpr type */
799 if ((reg = allocReg (REG_GPR)))
801 D (D_ALLOC, ("getRegGprNoSpil: got a reg.\n"));
806 /* just to make the compiler happy */
810 /** Symbol has a given register.
813 symHasReg (symbol * sym, regs * reg)
817 for (i = 0; i < sym->nRegs; i++)
818 if (sym->regs[i] == reg)
824 /** Check the live to and if they have registers & are not spilt then
825 free up the registers
828 deassignLRs (iCode * ic, eBBlock * ebp)
834 for (sym = hTabFirstItem (liveRanges, &k); sym;
835 sym = hTabNextItem (liveRanges, &k))
839 /* if it does not end here */
840 if (sym->liveTo > ic->seq)
843 /* if it was spilt on stack then we can
844 mark the stack spil location as free */
849 sym->usl.spillLoc->isFree = 1;
855 if (!bitVectBitValue (_G.regAssigned, sym->key))
858 /* special case check if this is an IFX &
859 the privious one was a pop and the
860 previous one was not spilt then keep track
862 if (ic->op == IFX && ic->prev &&
863 ic->prev->op == IPOP &&
864 !ic->prev->parmPush &&
865 !OP_SYMBOL (IC_LEFT (ic->prev))->isspilt)
866 psym = OP_SYMBOL (IC_LEFT (ic->prev));
868 D (D_ALLOC, ("deassignLRs: in loop on sym %p nregs %u\n", sym, sym->nRegs));
874 bitVectUnSetBit (_G.regAssigned, sym->key);
876 /* if the result of this one needs registers
877 and does not have it then assign it right
879 if (IC_RESULT (ic) &&
880 !(SKIP_IC2 (ic) || /* not a special icode */
881 ic->op == JUMPTABLE ||
886 (result = OP_SYMBOL (IC_RESULT (ic))) && /* has a result */
887 result->liveTo > ic->seq && /* and will live beyond this */
888 result->liveTo <= ebp->lSeq && /* does not go beyond this block */
889 result->regType == sym->regType && /* same register types */
890 result->nRegs && /* which needs registers */
891 !result->isspilt && /* and does not already have them */
893 !bitVectBitValue (_G.regAssigned, result->key) &&
894 /* the number of free regs + number of regs in this LR
895 can accomodate the what result Needs */
896 ((nfreeRegsType (result->regType) +
897 sym->nRegs) >= result->nRegs)
900 for (i = 0; i < result->nRegs; i++)
903 result->regs[i] = sym->regs[i];
905 result->regs[i] = getRegGpr (ic, ebp, result);
907 /* if the allocation falied which means
908 this was spilt then break */
909 if (!result->regs[i])
917 _G.regAssigned = bitVectSetBit (_G.regAssigned, result->key);
918 _G.totRegAssigned = bitVectSetBit (_G.totRegAssigned, result->key);
921 /* free the remaining */
922 for (; i < sym->nRegs; i++)
926 if (!symHasReg (psym, sym->regs[i]))
927 freeReg (sym->regs[i]);
930 freeReg (sym->regs[i]);
931 // sym->regs[i] = NULL;
938 /** Reassign this to registers.
941 reassignLR (operand * op)
943 symbol *sym = OP_SYMBOL (op);
946 D (D_ALLOC, ("reassingLR: on sym %p\n", sym));
948 /* not spilt any more */
949 sym->isspilt = sym->spillA = sym->blockSpil = sym->remainSpil = 0;
950 bitVectUnSetBit (_G.spiltSet, sym->key);
952 _G.regAssigned = bitVectSetBit (_G.regAssigned, sym->key);
953 _G.totRegAssigned = bitVectSetBit (_G.totRegAssigned, sym->key);
957 for (i = 0; i < sym->nRegs; i++)
958 sym->regs[i]->isFree = 0;
961 /** Determines if allocating will cause a spill.
964 willCauseSpill (int nr, int rt)
966 /* first check if there are any avlb registers
967 of te type required */
968 if (nFreeRegs (0) >= nr)
971 /* it will cause a spil */
975 /** The allocator can allocate same registers to result and operand,
976 if this happens make sure they are in the same position as the operand
977 otherwise chaos results.
980 positionRegs (symbol * result, symbol * opsym)
982 int count = min (result->nRegs, opsym->nRegs);
983 int i, j = 0, shared = 0;
986 D (D_ALLOC, ("positionRegs: on result %p opsum %p line %u\n", result, opsym, lineno));
988 /* if the result has been spilt then cannot share */
993 /* first make sure that they actually share */
994 for (i = 0; i < count; i++)
996 for (j = 0; j < count; j++)
998 if (result->regs[i] == opsym->regs[j] && i != j)
1008 regs *tmp = result->regs[i];
1009 result->regs[i] = result->regs[j];
1010 result->regs[j] = tmp;
1017 /** Try to allocate a pair of registers to the symbol.
1020 tryAllocatingRegPair (symbol * sym)
1023 wassert (sym->nRegs == 2);
1024 for (i = 0; i < _G.nRegs; i += 2)
1026 if ((regsZ80[i].isFree) && (regsZ80[i + 1].isFree))
1028 regsZ80[i].isFree = 0;
1029 sym->regs[0] = ®sZ80[i];
1030 regsZ80[i + 1].isFree = 0;
1031 sym->regs[1] = ®sZ80[i + 1];
1032 sym->regType = REG_PAIR;
1036 currFunc->regsUsed =
1037 bitVectSetBit (currFunc->regsUsed, i);
1038 currFunc->regsUsed =
1039 bitVectSetBit (currFunc->regsUsed, i + 1);
1041 D (D_ALLOC, ("tryAllocRegPair: succeded for sym %p\n", sym));
1045 D (D_ALLOC, ("tryAllocRegPair: failed on sym %p\n", sym));
1049 /** Serially allocate registers to the variables.
1050 This is the main register allocation function. It is called after
1054 serialRegAssign (eBBlock ** ebbs, int count)
1058 /* for all blocks */
1059 for (i = 0; i < count; i++)
1064 if (ebbs[i]->noPath &&
1065 (ebbs[i]->entryLabel != entryLabel &&
1066 ebbs[i]->entryLabel != returnLabel))
1069 /* of all instructions do */
1070 for (ic = ebbs[i]->sch; ic; ic = ic->next)
1073 /* if this is an ipop that means some live
1074 range will have to be assigned again */
1078 reassignLR (IC_LEFT (ic));
1081 /* if result is present && is a true symbol */
1082 if (IC_RESULT (ic) && ic->op != IFX &&
1083 IS_TRUE_SYMOP (IC_RESULT (ic)))
1084 OP_SYMBOL (IC_RESULT (ic))->allocreq++;
1086 /* take away registers from live
1087 ranges that end at this instruction */
1088 deassignLRs (ic, ebbs[i]);
1090 /* some don't need registers */
1091 /* MLH: removed RESULT and POINTER_SET condition */
1092 if (SKIP_IC2 (ic) ||
1093 ic->op == JUMPTABLE ||
1099 /* now we need to allocate registers only for the result */
1102 symbol *sym = OP_SYMBOL (IC_RESULT (ic));
1107 D (D_ALLOC, ("serialRegAssign: in loop on result %p\n", sym));
1109 /* if it does not need or is spilt
1110 or is already assigned to registers
1111 or will not live beyond this instructions */
1114 bitVectBitValue (_G.regAssigned, sym->key) ||
1115 sym->liveTo <= ic->seq)
1117 D (D_ALLOC, ("serialRegAssign: wont live long enough.\n"));
1121 /* if some liverange has been spilt at the block level
1122 and this one live beyond this block then spil this
1124 if (_G.blockSpil && sym->liveTo > ebbs[i]->lSeq)
1126 D (D_ALLOC, ("serialRegAssign: \"spilling to be safe.\"\n"));
1130 /* if trying to allocate this will cause
1131 a spill and there is nothing to spill
1132 or this one is rematerializable then
1134 willCS = willCauseSpill (sym->nRegs, sym->regType);
1135 spillable = computeSpillable (ic);
1137 (willCS && bitVectIsZero (spillable)))
1140 D (D_ALLOC, ("serialRegAssign: \"remat spill\"\n"));
1146 /* if it has a spillocation & is used less than
1147 all other live ranges then spill this */
1149 if (sym->usl.spillLoc) {
1150 symbol *leastUsed = leastUsedLR (liveRangesWith (spillable,
1151 allLRs, ebbs[i], ic));
1152 if (leastUsed && leastUsed->used > sym->used) {
1157 /* if none of the liveRanges have a spillLocation then better
1158 to spill this one than anything else already assigned to registers */
1159 if (liveRangesWith(spillable,noSpilLoc,ebbs[i],ic)) {
1160 /* if this is local to this block then we might find a block spil */
1161 if (!(sym->liveFrom >= ebbs[i]->fSeq && sym->liveTo <= ebbs[i]->lSeq)) {
1169 /* else we assign registers to it */
1170 _G.regAssigned = bitVectSetBit (_G.regAssigned, sym->key);
1171 _G.totRegAssigned = bitVectSetBit (_G.totRegAssigned, sym->key);
1173 /* Special case: Try to fit into a reg pair if
1175 D (D_ALLOC, ("serialRegAssign: actually allocing regs!\n"));
1176 if ((sym->nRegs == 2) && tryAllocatingRegPair (sym))
1181 for (j = 0; j < sym->nRegs; j++)
1183 sym->regs[j] = getRegGpr (ic, ebbs[i], sym);
1185 /* if the allocation falied which means
1186 this was spilt then break */
1189 D (D_ALLOC, ("Couldnt alloc (spill)\n"))
1194 /* if it shares registers with operands make sure
1195 that they are in the same position */
1196 if (IC_LEFT (ic) && IS_SYMOP (IC_LEFT (ic)) &&
1197 OP_SYMBOL (IC_LEFT (ic))->nRegs && ic->op != '=')
1198 positionRegs (OP_SYMBOL (IC_RESULT (ic)),
1199 OP_SYMBOL (IC_LEFT (ic)));
1200 /* do the same for the right operand */
1201 if (IC_RIGHT (ic) && IS_SYMOP (IC_RIGHT (ic)) &&
1202 OP_SYMBOL (IC_RIGHT (ic))->nRegs)
1203 positionRegs (OP_SYMBOL (IC_RESULT (ic)),
1204 OP_SYMBOL (IC_RIGHT (ic)));
1211 /*-----------------------------------------------------------------*/
1212 /* fillGaps - Try to fill in the Gaps left by Pass1 */
1213 /*-----------------------------------------------------------------*/
1214 static void fillGaps()
1219 if (getenv("DISABLE_FILL_GAPS")) return;
1221 /* look for livernages that was spilt by the allocator */
1222 for (sym = hTabFirstItem(liveRanges,&key) ; sym ;
1223 sym = hTabNextItem(liveRanges,&key)) {
1228 if (!sym->spillA || !sym->clashes || sym->remat) continue ;
1230 /* find the liveRanges this one clashes with, that are
1231 still assigned to registers & mark the registers as used*/
1232 for ( i = 0 ; i < sym->clashes->size ; i ++) {
1236 if (bitVectBitValue(sym->clashes,i) == 0 || /* those that clash with this */
1237 bitVectBitValue(_G.totRegAssigned,i) == 0) /* and are still assigned to registers */
1240 clr = hTabItemWithKey(liveRanges,i);
1243 /* mark these registers as used */
1244 for (k = 0 ; k < clr->nRegs ; k++ )
1245 useReg(clr->regs[k]);
1248 if (willCauseSpill(sym->nRegs,sym->regType)) {
1249 /* NOPE :( clear all registers & and continue */
1254 /* THERE IS HOPE !!!! */
1255 for (i=0; i < sym->nRegs ; i++ ) {
1256 sym->regs[i] = getRegGprNoSpil ();
1259 /* for all its definitions check if the registers
1260 allocated needs positioning NOTE: we can position
1261 only ONCE if more than One positioning required
1264 for (i = 0 ; i < sym->defs->size ; i++ ) {
1265 if (bitVectBitValue(sym->defs,i)) {
1267 if (!(ic = hTabItemWithKey(iCodehTab,i))) continue ;
1268 if (SKIP_IC(ic)) continue;
1269 assert(isSymbolEqual(sym,OP_SYMBOL(IC_RESULT(ic)))); /* just making sure */
1270 /* if left is assigned to registers */
1271 if (IS_SYMOP(IC_LEFT(ic)) &&
1272 bitVectBitValue(_G.totRegAssigned,OP_SYMBOL(IC_LEFT(ic))->key)) {
1273 pdone += positionRegs(sym,OP_SYMBOL(IC_LEFT(ic)));
1275 if (IS_SYMOP(IC_RIGHT(ic)) &&
1276 bitVectBitValue(_G.totRegAssigned,OP_SYMBOL(IC_RIGHT(ic))->key)) {
1277 pdone += positionRegs(sym,OP_SYMBOL(IC_RIGHT(ic)));
1279 if (pdone > 1) break;
1282 for (i = 0 ; i < sym->uses->size ; i++ ) {
1283 if (bitVectBitValue(sym->uses,i)) {
1285 if (!(ic = hTabItemWithKey(iCodehTab,i))) continue ;
1286 if (SKIP_IC(ic)) continue;
1287 if (!IS_ASSIGN_ICODE(ic)) continue ;
1289 /* if result is assigned to registers */
1290 if (IS_SYMOP(IC_RESULT(ic)) &&
1291 bitVectBitValue(_G.totRegAssigned,OP_SYMBOL(IC_RESULT(ic))->key)) {
1292 pdone += positionRegs(sym,OP_SYMBOL(IC_RESULT(ic)));
1294 if (pdone > 1) break;
1297 /* had to position more than once GIVE UP */
1299 /* UNDO all the changes we made to try this */
1301 for (i=0; i < sym->nRegs ; i++ ) {
1302 sym->regs[i] = NULL;
1305 D(D_FILL_GAPS,("Fill Gap gave up due to positioning for %s in function %s\n",sym->name, currFunc ? currFunc->name : "UNKNOWN"));
1308 D(D_FILL_GAPS,("FILLED GAP for %s in function %s\n",sym->name, currFunc ? currFunc->name : "UNKNOWN"));
1309 _G.totRegAssigned = bitVectSetBit(_G.totRegAssigned,sym->key);
1310 sym->isspilt = sym->spillA = 0 ;
1311 sym->usl.spillLoc->allocreq--;
1316 /*-----------------------------------------------------------------*/
1317 /* rUmaskForOp :- returns register mask for an operand */
1318 /*-----------------------------------------------------------------*/
1320 rUmaskForOp (operand * op)
1326 /* only temporaries are assigned registers */
1330 sym = OP_SYMBOL (op);
1332 /* if spilt or no registers assigned to it
1334 if (sym->isspilt || !sym->nRegs)
1337 rumask = newBitVect (_G.nRegs);
1339 for (j = 0; j < sym->nRegs; j++)
1341 rumask = bitVectSetBit (rumask, sym->regs[j]->rIdx);
1348 z80_rUmaskForOp (operand * op)
1350 return rUmaskForOp (op);
1353 /** Returns bit vector of registers used in iCode.
1356 regsUsedIniCode (iCode * ic)
1358 bitVect *rmask = newBitVect (_G.nRegs);
1360 /* do the special cases first */
1363 rmask = bitVectUnion (rmask,
1364 rUmaskForOp (IC_COND (ic)));
1368 /* for the jumptable */
1369 if (ic->op == JUMPTABLE)
1371 rmask = bitVectUnion (rmask,
1372 rUmaskForOp (IC_JTCOND (ic)));
1377 /* of all other cases */
1379 rmask = bitVectUnion (rmask,
1380 rUmaskForOp (IC_LEFT (ic)));
1384 rmask = bitVectUnion (rmask,
1385 rUmaskForOp (IC_RIGHT (ic)));
1388 rmask = bitVectUnion (rmask,
1389 rUmaskForOp (IC_RESULT (ic)));
1395 /** For each instruction will determine the regsUsed.
1398 createRegMask (eBBlock ** ebbs, int count)
1402 /* for all blocks */
1403 for (i = 0; i < count; i++)
1407 if (ebbs[i]->noPath &&
1408 (ebbs[i]->entryLabel != entryLabel &&
1409 ebbs[i]->entryLabel != returnLabel))
1412 /* for all instructions */
1413 for (ic = ebbs[i]->sch; ic; ic = ic->next)
1418 if (SKIP_IC2 (ic) || !ic->rlive)
1421 /* first mark the registers used in this
1423 ic->rUsed = regsUsedIniCode (ic);
1424 _G.funcrUsed = bitVectUnion (_G.funcrUsed, ic->rUsed);
1426 /* now create the register mask for those
1427 registers that are in use : this is a
1428 super set of ic->rUsed */
1429 ic->rMask = newBitVect (_G.nRegs + 1);
1431 /* for all live Ranges alive at this point */
1432 for (j = 1; j < ic->rlive->size; j++)
1437 /* if not alive then continue */
1438 if (!bitVectBitValue (ic->rlive, j))
1441 /* find the live range we are interested in */
1442 if (!(sym = hTabItemWithKey (liveRanges, j)))
1444 werror (E_INTERNAL_ERROR, __FILE__, __LINE__,
1445 "createRegMask cannot find live range");
1449 /* if no register assigned to it */
1450 if (!sym->nRegs || sym->isspilt)
1453 /* for all the registers allocated to it */
1454 for (k = 0; k < sym->nRegs; k++)
1457 bitVectSetBit (ic->rMask, sym->regs[k]->rIdx);
1463 /** Returns the rematerialized string for a remat var.
1466 rematStr (symbol * sym)
1469 iCode *ic = sym->rematiCode;
1474 /* if plus or minus print the right hand side */
1475 if (ic->op == '+' || ic->op == '-')
1477 sprintf (s, "0x%04x %c ", (int) operandLitValue (IC_RIGHT (ic)),
1480 ic = OP_SYMBOL (IC_LEFT (ic))->rematiCode;
1483 /* we reached the end */
1484 sprintf (s, "%s", OP_SYMBOL (IC_LEFT (ic))->rname);
1491 /*-----------------------------------------------------------------*/
1492 /* regTypeNum - computes the type & number of registers required */
1493 /*-----------------------------------------------------------------*/
1500 /* for each live range do */
1501 for (sym = hTabFirstItem (liveRanges, &k); sym;
1502 sym = hTabNextItem (liveRanges, &k))
1505 /* if used zero times then no registers needed */
1506 if ((sym->liveTo - sym->liveFrom) == 0)
1509 D (D_ALLOC, ("regTypeNum: loop on sym %p\n", sym));
1511 /* if the live range is a temporary */
1515 /* if the type is marked as a conditional */
1516 if (sym->regType == REG_CND)
1519 /* if used in return only then we don't
1521 if (sym->ruonly || sym->accuse)
1523 if (IS_AGGREGATE (sym->type) || sym->isptr)
1524 sym->type = aggrToPtr (sym->type, FALSE);
1528 /* if not then we require registers */
1529 D (D_ALLOC, ("regTypeNum: isagg %u nRegs %u type %p\n", IS_AGGREGATE (sym->type) || sym->isptr, sym->nRegs, sym->type));
1530 sym->nRegs = ((IS_AGGREGATE (sym->type) || sym->isptr) ?
1531 getSize (sym->type = aggrToPtr (sym->type, FALSE)) :
1532 getSize (sym->type));
1533 D (D_ALLOC, ("regTypeNum: setting nRegs of %s (%p) to %u\n", sym->name, sym, sym->nRegs));
1535 D (D_ALLOC, ("regTypeNum: setup to assign regs sym %p\n", sym));
1539 fprintf (stderr, "allocated more than 4 or 0 registers for type ");
1540 printTypeChain (sym->type, stderr);
1541 fprintf (stderr, "\n");
1544 /* determine the type of register required */
1545 /* Always general purpose */
1546 sym->regType = REG_GPR;
1551 /* for the first run we don't provide */
1552 /* registers for true symbols we will */
1553 /* see how things go */
1554 D (D_ALLOC, ("regTypeNum: #2 setting num of %p to 0\n", sym));
1561 /** Mark all registers as free.
1568 D (D_ALLOC, ("freeAllRegs: running.\n"));
1570 for (i = 0; i < _G.nRegs; i++)
1571 regsZ80[i].isFree = 1;
1574 /*-----------------------------------------------------------------*/
1575 /* deallocStackSpil - this will set the stack pointer back */
1576 /*-----------------------------------------------------------------*/
1577 DEFSETFUNC (deallocStackSpil)
1585 /** Register reduction for assignment.
1588 packRegsForAssign (iCode * ic, eBBlock * ebp)
1592 D (D_ALLOC, ("packRegsForAssign: running on ic %p\n", ic));
1594 if (!IS_ITEMP (IC_RIGHT (ic)) ||
1595 OP_SYMBOL (IC_RIGHT (ic))->isind ||
1596 OP_LIVETO (IC_RIGHT (ic)) > ic->seq)
1601 /* find the definition of iTempNN scanning backwards if we find a
1602 a use of the true symbol in before we find the definition then
1604 for (dic = ic->prev; dic; dic = dic->prev)
1606 /* PENDING: Don't pack across function calls. */
1607 if (dic->op == CALL || dic->op == PCALL)
1616 if (IS_SYMOP (IC_RESULT (dic)) &&
1617 IC_RESULT (dic)->key == IC_RIGHT (ic)->key)
1622 if (IS_SYMOP (IC_RIGHT (dic)) &&
1623 (IC_RIGHT (dic)->key == IC_RESULT (ic)->key ||
1624 IC_RIGHT (dic)->key == IC_RIGHT (ic)->key))
1630 if (IS_SYMOP (IC_LEFT (dic)) &&
1631 (IC_LEFT (dic)->key == IC_RESULT (ic)->key ||
1632 IC_LEFT (dic)->key == IC_RIGHT (ic)->key))
1640 return 0; /* did not find */
1642 /* if the result is on stack or iaccess then it must be
1643 the same atleast one of the operands */
1644 if (OP_SYMBOL (IC_RESULT (ic))->onStack ||
1645 OP_SYMBOL (IC_RESULT (ic))->iaccess)
1647 /* the operation has only one symbol
1648 operator then we can pack */
1649 if ((IC_LEFT (dic) && !IS_SYMOP (IC_LEFT (dic))) ||
1650 (IC_RIGHT (dic) && !IS_SYMOP (IC_RIGHT (dic))))
1653 if (!((IC_LEFT (dic) &&
1654 IC_RESULT (ic)->key == IC_LEFT (dic)->key) ||
1656 IC_RESULT (ic)->key == IC_RIGHT (dic)->key)))
1660 /* found the definition */
1661 /* replace the result with the result of */
1662 /* this assignment and remove this assignment */
1663 bitVectUnSetBit(OP_SYMBOL(IC_RESULT(dic))->defs,dic->key);
1664 IC_RESULT (dic) = IC_RESULT (ic);
1666 if (IS_ITEMP (IC_RESULT (dic)) && OP_SYMBOL (IC_RESULT (dic))->liveFrom > dic->seq)
1668 OP_SYMBOL (IC_RESULT (dic))->liveFrom = dic->seq;
1670 /* delete from liverange table also
1671 delete from all the points inbetween and the new
1673 for (sic = dic; sic != ic; sic = sic->next)
1675 bitVectUnSetBit (sic->rlive, IC_RESULT (ic)->key);
1676 if (IS_ITEMP (IC_RESULT (dic)))
1677 bitVectSetBit (sic->rlive, IC_RESULT (dic)->key);
1680 remiCodeFromeBBlock (ebp, ic);
1681 // PENDING: Check vs mcs51
1682 bitVectUnSetBit(OP_SYMBOL(IC_RESULT(ic))->defs,ic->key);
1683 hTabDeleteItem (&iCodehTab, ic->key, ic, DELETE_ITEM, NULL);
1684 OP_DEFS(IC_RESULT (dic))=bitVectSetBit (OP_DEFS (IC_RESULT (dic)), dic->key);
1688 /** Scanning backwards looks for first assig found.
1691 findAssignToSym (operand * op, iCode * ic)
1695 for (dic = ic->prev; dic; dic = dic->prev)
1698 /* if definition by assignment */
1699 if (dic->op == '=' &&
1700 !POINTER_SET (dic) &&
1701 IC_RESULT (dic)->key == op->key)
1702 /* && IS_TRUE_SYMOP(IC_RIGHT(dic)) */
1705 /* we are interested only if defined in far space */
1706 /* or in stack space in case of + & - */
1708 /* if assigned to a non-symbol then return
1710 if (!IS_SYMOP (IC_RIGHT (dic)))
1713 /* if the symbol is in far space then
1715 if (isOperandInFarSpace (IC_RIGHT (dic)))
1718 /* for + & - operations make sure that
1719 if it is on the stack it is the same
1720 as one of the three operands */
1721 if ((ic->op == '+' || ic->op == '-') &&
1722 OP_SYMBOL (IC_RIGHT (dic))->onStack)
1725 if (IC_RESULT (ic)->key != IC_RIGHT (dic)->key &&
1726 IC_LEFT (ic)->key != IC_RIGHT (dic)->key &&
1727 IC_RIGHT (ic)->key != IC_RIGHT (dic)->key)
1735 /* if we find an usage then we cannot delete it */
1736 if (IC_LEFT (dic) && IC_LEFT (dic)->key == op->key)
1739 if (IC_RIGHT (dic) && IC_RIGHT (dic)->key == op->key)
1742 if (POINTER_SET (dic) && IC_RESULT (dic)->key == op->key)
1746 /* now make sure that the right side of dic
1747 is not defined between ic & dic */
1750 iCode *sic = dic->next;
1752 for (; sic != ic; sic = sic->next)
1753 if (IC_RESULT (sic) &&
1754 IC_RESULT (sic)->key == IC_RIGHT (dic)->key)
1763 #if !DISABLE_PACKREGSFORSUPPORT
1766 /*-----------------------------------------------------------------*/
1767 /* packRegsForSupport :- reduce some registers for support calls */
1768 /*-----------------------------------------------------------------*/
1770 packRegsForSupport (iCode * ic, eBBlock * ebp)
1773 /* for the left & right operand :- look to see if the
1774 left was assigned a true symbol in far space in that
1775 case replace them */
1776 D (D_ALLOC, ("packRegsForSupport: running on ic %p\n", ic));
1778 if (IS_ITEMP (IC_LEFT (ic)) &&
1779 OP_SYMBOL (IC_LEFT (ic))->liveTo <= ic->seq)
1781 iCode *dic = findAssignToSym (IC_LEFT (ic), ic);
1787 /* found it we need to remove it from the
1789 for (sic = dic; sic != ic; sic = sic->next)
1790 bitVectUnSetBit (sic->rlive, IC_LEFT (ic)->key);
1792 IC_LEFT (ic)->operand.symOperand =
1793 IC_RIGHT (dic)->operand.symOperand;
1794 IC_LEFT (ic)->key = IC_RIGHT (dic)->operand.symOperand->key;
1795 remiCodeFromeBBlock (ebp, dic);
1796 bitVectUnSetBit(OP_SYMBOL(IC_RESULT(dic))->defs,dic->key);
1797 hTabDeleteItem (&iCodehTab, dic->key, dic, DELETE_ITEM, NULL);
1798 // PENDING: Check vs mcs51
1802 /* do the same for the right operand */
1805 IS_ITEMP (IC_RIGHT (ic)) &&
1806 OP_SYMBOL (IC_RIGHT (ic))->liveTo <= ic->seq)
1808 iCode *dic = findAssignToSym (IC_RIGHT (ic), ic);
1814 /* found it we need to remove it from the block */
1815 for (sic = dic; sic != ic; sic = sic->next)
1816 bitVectUnSetBit (sic->rlive, IC_RIGHT (ic)->key);
1818 IC_RIGHT (ic)->operand.symOperand =
1819 IC_RIGHT (dic)->operand.symOperand;
1820 IC_RIGHT (ic)->key = IC_RIGHT (dic)->operand.symOperand->key;
1822 remiCodeFromeBBlock (ebp, dic);
1823 bitVectUnSetBit(OP_SYMBOL(IC_RESULT(dic))->defs,dic->key);
1824 hTabDeleteItem (&iCodehTab, dic->key, dic, DELETE_ITEM, NULL);
1825 // PENDING: vs mcs51
1833 #define IS_OP_RUONLY(x) (x && IS_SYMOP(x) && OP_SYMBOL(x)->ruonly)
1835 /** Will reduce some registers for single use.
1838 packRegsForOneuse (iCode * ic, operand * op, eBBlock * ebp)
1844 D (D_ALLOC, ("packRegsForOneUse: running on ic %p\n", ic));
1846 /* if returning a literal then do nothing */
1850 /* only upto 2 bytes since we cannot predict
1851 the usage of b, & acc */
1852 if (getSize (operandType (op)) > 2)
1855 if (ic->op != RETURN &&
1859 /* this routine will mark the a symbol as used in one
1860 instruction use only && if the defintion is local
1861 (ie. within the basic block) && has only one definition &&
1862 that definiion is either a return value from a
1863 function or does not contain any variables in
1865 uses = bitVectCopy (OP_USES (op));
1866 bitVectUnSetBit (uses, ic->key); /* take away this iCode */
1867 if (!bitVectIsZero (uses)) /* has other uses */
1870 /* if it has only one defintion */
1871 if (bitVectnBitsOn (OP_DEFS (op)) > 1)
1872 return NULL; /* has more than one definition */
1874 /* get the that definition */
1876 hTabItemWithKey (iCodehTab,
1877 bitVectFirstBit (OP_DEFS (op)))))
1880 /* found the definition now check if it is local */
1881 if (dic->seq < ebp->fSeq ||
1882 dic->seq > ebp->lSeq)
1883 return NULL; /* non-local */
1885 /* now check if it is the return from a function call */
1886 if (dic->op == CALL || dic->op == PCALL)
1888 if (ic->op != SEND && ic->op != RETURN &&
1889 !POINTER_SET(ic) && !POINTER_GET(ic))
1891 OP_SYMBOL (op)->ruonly = 1;
1897 /* otherwise check that the definition does
1898 not contain any symbols in far space */
1899 if (isOperandInFarSpace (IC_LEFT (dic)) ||
1900 isOperandInFarSpace (IC_RIGHT (dic)) ||
1901 IS_OP_RUONLY (IC_LEFT (ic)) ||
1902 IS_OP_RUONLY (IC_RIGHT (ic)))
1907 /* if pointer set then make sure the pointer is one byte */
1908 if (POINTER_SET (dic))
1911 if (POINTER_GET (dic))
1916 /* also make sure the intervenening instructions
1917 don't have any thing in far space */
1918 for (dic = dic->next; dic && dic != ic; dic = dic->next)
1920 /* if there is an intervening function call then no */
1921 if (dic->op == CALL || dic->op == PCALL)
1923 /* if pointer set then make sure the pointer
1925 if (POINTER_SET (dic))
1928 if (POINTER_GET (dic))
1931 /* if address of & the result is remat the okay */
1932 if (dic->op == ADDRESS_OF &&
1933 OP_SYMBOL (IC_RESULT (dic))->remat)
1936 /* if left or right or result is in far space */
1937 if (isOperandInFarSpace (IC_LEFT (dic)) ||
1938 isOperandInFarSpace (IC_RIGHT (dic)) ||
1939 isOperandInFarSpace (IC_RESULT (dic)) ||
1940 IS_OP_RUONLY (IC_LEFT (dic)) ||
1941 IS_OP_RUONLY (IC_RIGHT (dic)) ||
1942 IS_OP_RUONLY (IC_RESULT (dic)))
1948 OP_SYMBOL (op)->ruonly = 1;
1952 /*-----------------------------------------------------------------*/
1953 /* isBitwiseOptimizable - requirements of JEAN LOUIS VERN */
1954 /*-----------------------------------------------------------------*/
1956 isBitwiseOptimizable (iCode * ic)
1958 sym_link *rtype = getSpec (operandType (IC_RIGHT (ic)));
1960 /* bitwise operations are considered optimizable
1961 under the following conditions (Jean-Louis VERN)
1973 if (IS_LITERAL (rtype))
1979 Certian assignments involving pointers can be temporarly stored
1990 #if !DISABLE_PACKREGSFORACCUSE
1993 /** Pack registers for acc use.
1994 When the result of this operation is small and short lived it may
1995 be able to be stored in the accumelator.
1998 packRegsForAccUse (iCode * ic)
2002 /* if this is an aggregate, e.g. a one byte char array */
2003 if (IS_AGGREGATE(operandType(IC_RESULT(ic)))) {
2007 /* if + or - then it has to be one byte result */
2008 if ((ic->op == '+' || ic->op == '-')
2009 && getSize (operandType (IC_RESULT (ic))) > 1)
2012 /* if shift operation make sure right side is not a literal */
2013 if (ic->op == RIGHT_OP &&
2014 (isOperandLiteral (IC_RIGHT (ic)) ||
2015 getSize (operandType (IC_RESULT (ic))) > 1))
2018 if (ic->op == LEFT_OP &&
2019 (isOperandLiteral (IC_RIGHT (ic)) ||
2020 getSize (operandType (IC_RESULT (ic))) > 1))
2023 /* has only one definition */
2024 if (bitVectnBitsOn (OP_DEFS (IC_RESULT (ic))) > 1)
2027 /* has only one use */
2028 if (bitVectnBitsOn (OP_USES (IC_RESULT (ic))) > 1)
2031 /* and the usage immediately follows this iCode */
2032 if (!(uic = hTabItemWithKey (iCodehTab,
2033 bitVectFirstBit (OP_USES (IC_RESULT (ic))))))
2036 if (ic->next != uic)
2039 /* if it is a conditional branch then we definitely can */
2043 if (uic->op == JUMPTABLE)
2047 /* if the usage is not is an assignment or an
2048 arithmetic / bitwise / shift operation then not */
2049 if (POINTER_SET (uic) &&
2050 getSize (aggrToPtr (operandType (IC_RESULT (uic)), FALSE)) > 1)
2054 if (uic->op != '=' &&
2055 !IS_ARITHMETIC_OP (uic) &&
2056 !IS_BITWISE_OP (uic) &&
2057 uic->op != LEFT_OP &&
2058 uic->op != RIGHT_OP)
2061 /* if used in ^ operation then make sure right is not a
2063 if (uic->op == '^' && isOperandLiteral (IC_RIGHT (uic)))
2066 /* if shift operation make sure right side is not a literal */
2067 if (uic->op == RIGHT_OP &&
2068 (isOperandLiteral (IC_RIGHT (uic)) ||
2069 getSize (operandType (IC_RESULT (uic))) > 1))
2072 if (uic->op == LEFT_OP &&
2073 (isOperandLiteral (IC_RIGHT (uic)) ||
2074 getSize (operandType (IC_RESULT (uic))) > 1))
2078 /* make sure that the result of this icode is not on the
2079 stack, since acc is used to compute stack offset */
2080 if (IS_TRUE_SYMOP (IC_RESULT (uic)) &&
2081 OP_SYMBOL (IC_RESULT (uic))->onStack)
2086 /* if either one of them in far space then we cannot */
2087 if ((IS_TRUE_SYMOP (IC_LEFT (uic)) &&
2088 isOperandInFarSpace (IC_LEFT (uic))) ||
2089 (IS_TRUE_SYMOP (IC_RIGHT (uic)) &&
2090 isOperandInFarSpace (IC_RIGHT (uic))))
2094 /* if the usage has only one operand then we can */
2095 if (IC_LEFT (uic) == NULL ||
2096 IC_RIGHT (uic) == NULL)
2099 /* make sure this is on the left side if not
2100 a '+' since '+' is commutative */
2101 if (ic->op != '+' &&
2102 IC_LEFT (uic)->key != IC_RESULT (ic)->key)
2105 // See mcs51 ralloc for reasoning
2107 /* if one of them is a literal then we can */
2108 if ((IC_LEFT (uic) && IS_OP_LITERAL (IC_LEFT (uic))) ||
2109 (IC_RIGHT (uic) && IS_OP_LITERAL (IC_RIGHT (uic))))
2116 /** This is confusing :) Guess for now */
2117 if (IC_LEFT (uic)->key == IC_RESULT (ic)->key &&
2118 (IS_ITEMP (IC_RIGHT (uic)) ||
2119 (IS_TRUE_SYMOP (IC_RIGHT (uic)))))
2122 if (IC_RIGHT (uic)->key == IC_RESULT (ic)->key &&
2123 (IS_ITEMP (IC_LEFT (uic)) ||
2124 (IS_TRUE_SYMOP (IC_LEFT (uic)))))
2128 OP_SYMBOL (IC_RESULT (ic))->accuse = ACCUSE_A;
2133 packRegsForHLUse (iCode * ic)
2137 /* PENDING: Could do IFX */
2143 /* has only one definition */
2144 if (bitVectnBitsOn (OP_DEFS (IC_RESULT (ic))) > 1)
2146 D (D_HLUSE, (" + Dropping as has more than one def\n"));
2150 /* has only one use */
2151 if (bitVectnBitsOn (OP_USES (IC_RESULT (ic))) > 1)
2153 D (D_HLUSE, (" + Dropping as has more than one use\n"));
2157 /* and the usage immediately follows this iCode */
2158 if (!(uic = hTabItemWithKey (iCodehTab,
2159 bitVectFirstBit (OP_USES (IC_RESULT (ic))))))
2161 D (D_HLUSE, (" + Dropping as usage isn't in this block\n"));
2165 if (ic->next != uic)
2167 D (D_HLUSE, (" + Dropping as usage doesn't follow this\n"));
2176 if (getSize (operandType (IC_RESULT (ic))) != 2 ||
2177 (IC_LEFT(uic) && getSize (operandType (IC_LEFT (uic))) != 2) ||
2178 (IC_RIGHT(uic) && getSize (operandType (IC_RIGHT (uic))) != 2))
2180 D (D_HLUSE, (" + Dropping as the result size is not 2\n"));
2186 if (ic->op == CAST && uic->op == IPUSH)
2188 if (ic->op == ADDRESS_OF && uic->op == IPUSH)
2190 if (ic->op == ADDRESS_OF && POINTER_GET (uic) && IS_ITEMP( IC_RESULT (uic)))
2192 if (ic->op == CALL && ic->parmBytes == 0 && (uic->op == '-' || uic->op == '+'))
2197 /* Case of assign a constant to offset in a static array. */
2198 if (ic->op == '+' && IS_VALOP (IC_RIGHT (ic)))
2200 if (uic->op == '=' && POINTER_SET (uic))
2204 else if (uic->op == IPUSH && getSize (operandType (IC_LEFT (uic))) == 2)
2211 D (D_HLUSE, (" + Dropping as it's a bad op\n"));
2214 OP_SYMBOL (IC_RESULT (ic))->accuse = ACCUSE_SCRATCH;
2218 packRegsForHLUse3 (iCode * lic, operand * op, eBBlock * ebp)
2223 bool isFirst = TRUE;
2225 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));
2229 if ( OP_SYMBOL(op)->accuse)
2234 if (OP_SYMBOL(op)->remat)
2239 /* Only defined once */
2240 if (bitVectnBitsOn (OP_DEFS (op)) > 1)
2243 if (getSize (operandType (op)) > 2)
2246 /* And this is the definition */
2247 if (bitVectFirstBit (OP_DEFS (op)) != lic->key)
2250 /* first check if any overlapping liverange has already been
2252 if (OP_SYMBOL(op)->clashes)
2254 for (i = 0 ; i < OP_SYMBOL(op)->clashes->size ; i++ )
2256 if (bitVectBitValue(OP_SYMBOL(op)->clashes,i))
2258 sym = hTabItemWithKey(liveRanges,i);
2259 if (sym->accuse == ACCUSE_SCRATCH)
2267 /* Nothing else that clashes with this is using the scratch
2268 register. Scan through all of the intermediate instructions and
2269 see if any of them could nuke HL.
2271 dic = ic = hTabFirstItemWK(iCodeSeqhTab,OP_SYMBOL(op)->liveFrom);
2273 for (; ic && ic->seq <= OP_SYMBOL(op)->liveTo;
2274 ic = hTabNextItem(iCodeSeqhTab, &key))
2278 D (D_PACK_HLUSE3, ("(On %p: op: %u next: %p)\n", ic, ic->op, ic->next));
2283 if (ic->op == ADDRESS_OF)
2285 if (POINTER_GET (ic))
2287 if (ic->op == '=' && !POINTER_SET(ic))
2291 if (IC_RESULT(ic) && IS_SYMOP(IC_RESULT(ic))
2292 && isOperandInDirSpace (IC_RESULT (ic)))
2295 if (IC_LEFT(ic) && IS_SYMOP(IC_LEFT(ic))
2296 && isOperandInDirSpace (IC_LEFT (ic)))
2299 if (IC_RIGHT(ic) && IS_SYMOP(IC_RIGHT(ic))
2300 && isOperandInDirSpace (IC_RIGHT (ic)))
2303 /* Handle the non left/right/result ones first */
2306 if (ic->op == JUMPTABLE)
2315 if (ic->op == IPUSH && isOperandEqual (op, IC_LEFT (ic)))
2318 if (ic->op == SEND && isOperandEqual (op, IC_LEFT (ic)))
2321 if (ic->op == CALL && isOperandEqual (op, IC_RESULT (ic)))
2324 if (ic->op == LEFT_OP && isOperandLiteral (IC_RIGHT (ic)))
2327 if ((ic->op == '=' && !POINTER_SET(ic)) ||
2328 ic->op == UNARYMINUS ||
2337 if (ic->op == '*' && isOperandEqual (op, IC_LEFT (ic)))
2340 if (POINTER_SET (ic) && isOperandEqual (op, IC_RESULT (ic)))
2343 if (POINTER_GET (ic) && isOperandEqual (op, IC_LEFT (ic)))
2346 if (IS_VALOP (IC_RIGHT (ic)) &&
2353 /* By default give up */
2357 D (D_PACK_HLUSE3, ("Succeeded!\n"))
2359 OP_SYMBOL (op)->accuse = ACCUSE_SCRATCH;
2364 packRegsForIYUse (iCode * lic, operand * op, eBBlock * ebp)
2371 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));
2375 if ( OP_SYMBOL(op)->accuse)
2380 if (OP_SYMBOL(op)->remat)
2385 /* Only defined once */
2386 if (bitVectnBitsOn (OP_DEFS (op)) > 1)
2389 /* And this is the definition */
2390 if (bitVectFirstBit (OP_DEFS (op)) != lic->key)
2393 /* first check if any overlapping liverange has already been
2395 if (OP_SYMBOL(op)->clashes)
2397 for (i = 0 ; i < OP_SYMBOL(op)->clashes->size ; i++ )
2399 if (bitVectBitValue(OP_SYMBOL(op)->clashes,i))
2401 sym = hTabItemWithKey(liveRanges,i);
2402 if (sym->accuse == ACCUSE_IY)
2410 /* Only a few instructions can load into IY */
2416 if (getSize (operandType (op)) != 2)
2418 D (D_ACCUSE2, (" + Dropping as operation has size is too big\n"));
2422 /* Nothing else that clashes with this is using the scratch
2423 register. Scan through all of the intermediate instructions and
2424 see if any of them could nuke HL.
2426 dic = ic = hTabFirstItemWK(iCodeSeqhTab,OP_SYMBOL(op)->liveFrom);
2429 for (; ic && ic->seq <= OP_SYMBOL(op)->liveTo;
2430 ic = hTabNextItem(iCodeSeqhTab,&key))
2435 if (ic->op == PCALL ||
2444 /* Be pessamistic. */
2448 D (D_PACK_IY, (" op: %u uses %u result: %d left: %d right: %d\n", ic->op, bitVectBitValue(uses, ic->key),
2449 IC_RESULT(ic) && IS_SYMOP(IC_RESULT(ic)) ? isOperandInDirSpace(IC_RESULT(ic)) : -1,
2450 IC_LEFT(ic) && IS_SYMOP(IC_LEFT(ic)) ? isOperandInDirSpace(IC_LEFT(ic)) : -1,
2451 IC_RIGHT(ic) && IS_SYMOP(IC_RIGHT(ic)) ? isOperandInDirSpace(IC_RIGHT(ic)) : -1
2454 if (IC_RESULT(ic) && IS_SYMOP(IC_RESULT(ic)) &&
2455 isOperandInDirSpace(IC_RESULT(ic)))
2458 if (IC_RIGHT(ic) && IS_SYMOP(IC_RIGHT(ic)) &&
2459 isOperandInDirSpace(IC_RIGHT(ic)))
2462 if (IC_LEFT(ic) && IS_SYMOP(IC_LEFT(ic)) &&
2463 isOperandInDirSpace(IC_LEFT(ic)))
2466 /* Only certain rules will work against IY. Check if this iCode uses
2468 if (bitVectBitValue(uses, ic->key) != 0)
2470 if (ic->op == '=' &&
2471 isOperandEqual(IC_RESULT(ic), op))
2474 if (ic->op == GET_VALUE_AT_ADDRESS &&
2475 isOperandEqual(IC_LEFT(ic), op))
2478 if (isOperandEqual(IC_RESULT(ic), IC_LEFT(ic)) == FALSE)
2481 if (IC_RIGHT (ic) && IS_VALOP (IC_RIGHT (ic)))
2483 if (ic->op == '+' ||
2486 /* Only works if the constant is small */
2487 if (operandLitValue (IC_RIGHT (ic)) < 4)
2496 /* This iCode doesn't use the sym. See if this iCode preserves IY.
2501 /* By default give up */
2505 D (D_PACK_IY, ("Succeeded IY!\n"));
2507 OP_SYMBOL (op)->accuse = ACCUSE_IY;
2511 /** Returns TRUE if this operation can use acc and if it preserves the value.
2514 opPreservesA (iCode * uic)
2518 /* If we've gotten this far then the thing to compare must be
2519 small enough and must be in A.
2524 if (uic->op == JUMPTABLE)
2526 D (D_ACCUSE2, (" + Dropping as operation is a Jumptable\n"));
2530 /* A pointer assign preserves A if A is the left value. */
2531 if (uic->op == '=' && POINTER_SET (uic))
2536 /* if the usage has only one operand then we can */
2537 /* PENDING: check */
2538 if (IC_LEFT (uic) == NULL ||
2539 IC_RIGHT (uic) == NULL)
2541 D (D_ACCUSE2, (" + Dropping as operation has only one operand\n"));
2545 /* PENDING: check this rule */
2546 if (getSize (operandType (IC_RESULT (uic))) > 1)
2548 D (D_ACCUSE2, (" + Dropping as operation has size is too big\n"));
2553 /* Disabled all of the old rules as they weren't verified and have
2554 caused at least one problem.
2559 /** Returns true if this operand preserves the value of A.
2562 opIgnoresA (iCode * ic, iCode * uic)
2564 /* A increment of an iTemp by a constant is OK. */
2565 if ( uic->op == '+' &&
2566 IS_ITEMP (IC_LEFT (uic)) &&
2567 IS_ITEMP (IC_RESULT (uic)) &&
2568 IS_OP_LITERAL (IC_RIGHT (uic)))
2570 unsigned int icount = (unsigned int) floatFromVal (IC_RIGHT (uic)->operand.valOperand);
2572 /* Being an ITEMP means that we're already a symbol. */
2574 IC_RESULT (uic)->operand.symOperand->key == IC_LEFT (uic)->operand.symOperand->key
2580 else if (uic->op == '=' && !POINTER_SET (uic))
2582 /* If they are equal and get optimised out then things are OK. */
2583 if (isOperandEqual (IC_RESULT (uic), IC_RIGHT (uic)))
2585 /* Straight assign is OK. */
2594 /* Some optimisation cases:
2606 ; genAssign (pointer)
2610 want to optimise down to:
2616 So genPointer get is OK
2617 genPlus where the right is constant, left is iTemp, and result is same as left
2618 genAssign (pointer) is OK
2629 ; genAssign (pointer)
2630 ; AOP_STK for _strcpy_to_1_1
2635 want to optimise down to:
2641 So genIfx where IC_COND has size of 1 and is a constant.
2644 /** Pack registers for acc use.
2645 When the result of this operation is small and short lived it may
2646 be able to be stored in the accumulator.
2648 Note that the 'A preserving' list is currently emperical :)
2651 packRegsForAccUse2 (iCode * ic)
2655 D (D_ACCUSE2, ("packRegsForAccUse2: running on ic %p line %u\n", ic, ic->lineno));
2659 /* Filter out all but those 'good' commands */
2661 !POINTER_GET (ic) &&
2664 !IS_BITWISE_OP (ic) &&
2670 ic->op != GETHBIT &&
2673 D (D_ACCUSE2, (" + Dropping as not a 'good' source command\n"));
2677 /* if + or - then it has to be one byte result.
2680 if ((ic->op == '+' || ic->op == '-')
2681 && getSize (operandType (IC_RESULT (ic))) > 1)
2683 D (D_ACCUSE2, (" + Dropping as it's a big + or -\n"));
2687 /* has only one definition */
2688 if (bitVectnBitsOn (OP_DEFS (IC_RESULT (ic))) > 1)
2690 D (D_ACCUSE2, (" + Dropping as it has more than one definition\n"));
2694 /* Right. We may be able to propagate it through if:
2695 For each in the chain of uses the intermediate is OK.
2697 /* Get next with 'uses result' bit on
2698 If this->next == next
2699 Validate use of next
2700 If OK, increase count
2702 /* and the usage immediately follows this iCode */
2703 if (!(uic = hTabItemWithKey (iCodehTab,
2704 bitVectFirstBit (OP_USES (IC_RESULT (ic))))))
2706 D (D_ACCUSE2, (" + Dropping as usage does not follow first\n"));
2711 /* Create a copy of the OP_USES bit vect */
2712 bitVect *uses = bitVectCopy (OP_USES (IC_RESULT (ic)));
2714 iCode *scan = ic, *next;
2718 setBit = bitVectFirstBit (uses);
2719 next = hTabItemWithKey (iCodehTab, setBit);
2720 if (scan->next == next)
2722 D (D_ACCUSE2_VERBOSE, (" ! Is next in line\n"));
2724 bitVectUnSetBit (uses, setBit);
2725 /* Still contigous. */
2726 if (!opPreservesA (next))
2728 D (D_ACCUSE2, (" + Dropping as operation doesn't preserve A\n"));
2731 D (D_ACCUSE2_VERBOSE, (" ! Preserves A, so continue scanning\n"));
2734 else if (scan->next == NULL && bitVectnBitsOn (uses) == 1 && next != NULL)
2736 if (next->prev == NULL)
2738 if (!opPreservesA (next))
2740 D (D_ACCUSE2, (" + Dropping as operation doesn't preserve A #2\n"));
2743 bitVectUnSetBit (uses, setBit);
2748 D (D_ACCUSE2, (" + Dropping as last in list and next doesn't start a block\n"));
2752 else if (scan->next == NULL)
2754 D (D_ACCUSE2, (" + Dropping as hit the end of the list\n"));
2755 D (D_ACCUSE2, (" + Next in htab: %p\n", next));
2760 if (opIgnoresA (ic, scan->next))
2764 D (D_ACCUSE2_VERBOSE, (" ! Op ignores A, so continue scanning\n"));
2768 D (D_ACCUSE2, (" + Dropping as parts are not consecuitive and intermediate might use A\n"));
2773 while (!bitVectIsZero (uses));
2775 OP_SYMBOL (IC_RESULT (ic))->accuse = ACCUSE_A;
2780 /** Does some transformations to reduce register pressure.
2783 packRegisters (eBBlock * ebp)
2788 D (D_ALLOC, ("packRegisters: entered.\n"));
2790 while (1 && !DISABLE_PACK_ASSIGN)
2793 /* look for assignments of the form */
2794 /* iTempNN = TRueSym (someoperation) SomeOperand */
2796 /* TrueSym := iTempNN:1 */
2797 for (ic = ebp->sch; ic; ic = ic->next)
2799 /* find assignment of the form TrueSym := iTempNN:1 */
2800 if (ic->op == '=' && !POINTER_SET (ic))
2801 change += packRegsForAssign (ic, ebp);
2807 for (ic = ebp->sch; ic; ic = ic->next)
2809 /* Safe: address of a true sym is always constant. */
2810 /* if this is an itemp & result of a address of a true sym
2811 then mark this as rematerialisable */
2812 D (D_ALLOC, ("packRegisters: looping on ic %p\n", ic));
2814 if (ic->op == ADDRESS_OF &&
2815 IS_ITEMP (IC_RESULT (ic)) &&
2816 IS_TRUE_SYMOP (IC_LEFT (ic)) &&
2817 bitVectnBitsOn (OP_DEFS (IC_RESULT (ic))) == 1 &&
2818 !OP_SYMBOL (IC_LEFT (ic))->onStack)
2821 OP_SYMBOL (IC_RESULT (ic))->remat = 1;
2822 OP_SYMBOL (IC_RESULT (ic))->rematiCode = ic;
2823 OP_SYMBOL (IC_RESULT (ic))->usl.spillLoc = NULL;
2826 /* Safe: just propagates the remat flag */
2827 /* if straight assignment then carry remat flag if this is the
2829 if (ic->op == '=' &&
2830 !POINTER_SET (ic) &&
2831 IS_SYMOP (IC_RIGHT (ic)) &&
2832 OP_SYMBOL (IC_RIGHT (ic))->remat &&
2833 bitVectnBitsOn (OP_SYMBOL (IC_RESULT (ic))->defs) <= 1)
2836 OP_SYMBOL (IC_RESULT (ic))->remat =
2837 OP_SYMBOL (IC_RIGHT (ic))->remat;
2838 OP_SYMBOL (IC_RESULT (ic))->rematiCode =
2839 OP_SYMBOL (IC_RIGHT (ic))->rematiCode;
2842 /* if the condition of an if instruction is defined in the
2843 previous instruction then mark the itemp as a conditional */
2844 if ((IS_CONDITIONAL (ic) ||
2845 ((ic->op == BITWISEAND ||
2848 isBitwiseOptimizable (ic))) &&
2849 ic->next && ic->next->op == IFX &&
2850 bitVectnBitsOn (OP_USES(IC_RESULT(ic)))==1 &&
2851 isOperandEqual (IC_RESULT (ic), IC_COND (ic->next)) &&
2852 OP_SYMBOL (IC_RESULT (ic))->liveTo <= ic->next->seq)
2855 OP_SYMBOL (IC_RESULT (ic))->regType = REG_CND;
2860 /* reduce for support function calls */
2861 if (ic->supportRtn || ic->op == '+' || ic->op == '-')
2862 packRegsForSupport (ic, ebp);
2865 /* some cases the redundant moves can
2866 can be eliminated for return statements */
2867 if (ic->op == RETURN || ic->op == SEND)
2869 packRegsForOneuse (ic, IC_LEFT (ic), ebp);
2872 /* if pointer set & left has a size more than
2873 one and right is not in far space */
2874 if (!DISABLE_PACK_ONE_USE &&
2876 /* MLH: no such thing.
2877 !isOperandInFarSpace(IC_RIGHT(ic)) && */
2878 !OP_SYMBOL (IC_RESULT (ic))->remat &&
2879 !IS_OP_RUONLY (IC_RIGHT (ic)) &&
2880 getSize (aggrToPtr (operandType (IC_RESULT (ic)), FALSE)) > 1)
2883 packRegsForOneuse (ic, IC_RESULT (ic), ebp);
2886 /* if pointer get */
2887 if (!DISABLE_PACK_ONE_USE &&
2889 IS_SYMOP (IC_LEFT (ic)) &&
2890 /* MLH: dont have far space
2891 !isOperandInFarSpace(IC_RESULT(ic))&& */
2892 !OP_SYMBOL (IC_LEFT (ic))->remat &&
2893 !IS_OP_RUONLY (IC_RESULT (ic)) &&
2894 getSize (aggrToPtr (operandType (IC_LEFT (ic)), FALSE)) > 1)
2897 packRegsForOneuse (ic, IC_LEFT (ic), ebp);
2900 /* pack registers for accumulator use, when the result of an
2901 arithmetic or bit wise operation has only one use, that use is
2902 immediately following the defintion and the using iCode has
2903 only one operand or has two operands but one is literal & the
2904 result of that operation is not on stack then we can leave the
2905 result of this operation in acc:b combination */
2907 if (!DISABLE_PACK_HL && IS_ITEMP (IC_RESULT (ic)))
2913 packRegsForHLUse (ic);
2917 packRegsForHLUse3 (ic, IC_RESULT (ic), ebp);
2921 if (!DISABLE_PACK_IY && IS_ITEMP (IC_RESULT (ic)) && IS_Z80)
2923 packRegsForIYUse (ic, IC_RESULT (ic), ebp);
2926 if (!DISABLE_PACK_ACC && IS_ITEMP (IC_RESULT (ic)) &&
2927 getSize (operandType (IC_RESULT (ic))) == 1)
2929 packRegsForAccUse2 (ic);
2934 /** Joins together two byte constant pushes into one word push.
2937 joinPushes (iCode *lic)
2941 for (ic = lic; ic; ic = ic->next)
2948 /* Anything past this? */
2953 /* This and the next pushes? */
2954 if (ic->op != IPUSH || uic->op != IPUSH)
2958 /* Both literals? */
2959 if ( !IS_OP_LITERAL (IC_LEFT (ic)) || !IS_OP_LITERAL (IC_LEFT (uic)))
2963 /* Both characters? */
2964 if ( getSize (operandType (IC_LEFT (ic))) != 1 || getSize (operandType (IC_LEFT (uic))) != 1)
2968 /* Pull out the values, make a new type, and create the new iCode for it.
2970 first = (int)operandLitValue ( IC_LEFT (ic));
2971 second = (int)operandLitValue ( IC_LEFT (uic));
2973 sprintf (buffer, "%uu", ((first << 8) | (second & 0xFF)) & 0xFFFFU);
2974 val = constVal (buffer);
2975 SPEC_NOUN (val->type) = V_INT;
2976 IC_LEFT (ic) = operandFromOperand (IC_LEFT (ic));
2977 IC_LEFT (ic)->operand.valOperand = val;
2979 /* Now remove the second one from the list. */
2980 ic->next = uic->next;
2983 /* Patch up the reverse link */
2984 uic->next->prev = ic;
2991 /*-----------------------------------------------------------------*/
2992 /* assignRegisters - assigns registers to each live range as need */
2993 /*-----------------------------------------------------------------*/
2995 z80_assignRegisters (eBBlock ** ebbs, int count)
3000 D (D_ALLOC, ("\n-> z80_assignRegisters: entered.\n"));
3002 setToNull ((void *) &_G.funcrUsed);
3003 setToNull ((void *) &_G.totRegAssigned);
3004 _G.stackExtend = _G.dataExtend = 0;
3008 /* DE is required for the code gen. */
3009 _G.nRegs = GBZ80_MAX_REGS;
3010 regsZ80 = _gbz80_regs;
3014 _G.nRegs = Z80_MAX_REGS;
3015 regsZ80 = _z80_regs;
3018 /* change assignments this will remove some
3019 live ranges reducing some register pressure */
3020 for (i = 0; i < count; i++)
3021 packRegisters (ebbs[i]);
3023 /* liveranges probably changed by register packing
3024 so we compute them again */
3025 recomputeLiveRanges (ebbs, count);
3027 if (options.dump_pack)
3028 dumpEbbsToFileExt (DUMP_PACK, ebbs, count);
3030 /* first determine for each live range the number of
3031 registers & the type of registers required for each */
3034 /* and serially allocate registers */
3035 serialRegAssign (ebbs, count);
3040 /* if stack was extended then tell the user */
3043 /* werror(W_TOOMANY_SPILS,"stack", */
3044 /* _G.stackExtend,currFunc->name,""); */
3050 /* werror(W_TOOMANY_SPILS,"data space", */
3051 /* _G.dataExtend,currFunc->name,""); */
3055 if (options.dump_rassgn) {
3056 dumpEbbsToFileExt (DUMP_RASSGN, ebbs, count);
3057 dumpLiveRanges (DUMP_LRANGE, liveRanges);
3060 /* after that create the register mask
3061 for each of the instruction */
3062 createRegMask (ebbs, count);
3064 /* now get back the chain */
3065 ic = iCodeLabelOptimize (iCodeFromeBBlock (ebbs, count));
3067 ic = joinPushes (ic);
3069 /* redo that offsets for stacked automatic variables */
3070 redoStackOffsets ();
3074 /* free up any stackSpil locations allocated */
3075 applyToSet (_G.stackSpil, deallocStackSpil);
3077 setToNull ((void *) &_G.stackSpil);
3078 setToNull ((void *) &_G.spiltSet);
3079 /* mark all registers as free */