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 /*------------------------------------------------------------------*/
1050 /* verifyRegsAssigned - make sure an iTemp is properly initialized; */
1051 /* it should either have registers or have beed spilled. Otherwise, */
1052 /* there was an uninitialized variable, so just spill this to get */
1053 /* the operand in a valid state. */
1054 /*------------------------------------------------------------------*/
1056 verifyRegsAssigned (operand *op, iCode * ic)
1061 if (!IS_ITEMP (op)) return;
1063 sym = OP_SYMBOL (op);
1064 if (sym->isspilt) return;
1065 if (!sym->nRegs) return;
1066 if (sym->regs[0]) return;
1068 werrorfl (ic->filename, ic->lineno, W_LOCAL_NOINIT,
1069 sym->prereqv ? sym->prereqv->name : sym->name);
1074 /** Serially allocate registers to the variables.
1075 This is the main register allocation function. It is called after
1079 serialRegAssign (eBBlock ** ebbs, int count)
1083 /* for all blocks */
1084 for (i = 0; i < count; i++)
1089 if (ebbs[i]->noPath &&
1090 (ebbs[i]->entryLabel != entryLabel &&
1091 ebbs[i]->entryLabel != returnLabel))
1094 /* of all instructions do */
1095 for (ic = ebbs[i]->sch; ic; ic = ic->next)
1098 /* if this is an ipop that means some live
1099 range will have to be assigned again */
1103 reassignLR (IC_LEFT (ic));
1106 /* if result is present && is a true symbol */
1107 if (IC_RESULT (ic) && ic->op != IFX &&
1108 IS_TRUE_SYMOP (IC_RESULT (ic)))
1109 OP_SYMBOL (IC_RESULT (ic))->allocreq++;
1111 /* take away registers from live
1112 ranges that end at this instruction */
1113 deassignLRs (ic, ebbs[i]);
1115 /* some don't need registers */
1116 /* MLH: removed RESULT and POINTER_SET condition */
1117 if (SKIP_IC2 (ic) ||
1118 ic->op == JUMPTABLE ||
1124 /* now we need to allocate registers only for the result */
1127 symbol *sym = OP_SYMBOL (IC_RESULT (ic));
1132 D (D_ALLOC, ("serialRegAssign: in loop on result %p\n", sym));
1134 /* if it does not need or is spilt
1135 or is already assigned to registers
1136 or will not live beyond this instructions */
1139 bitVectBitValue (_G.regAssigned, sym->key) ||
1140 sym->liveTo <= ic->seq)
1142 D (D_ALLOC, ("serialRegAssign: wont live long enough.\n"));
1146 /* if some liverange has been spilt at the block level
1147 and this one live beyond this block then spil this
1149 if (_G.blockSpil && sym->liveTo > ebbs[i]->lSeq)
1151 D (D_ALLOC, ("serialRegAssign: \"spilling to be safe.\"\n"));
1155 /* if trying to allocate this will cause
1156 a spill and there is nothing to spill
1157 or this one is rematerializable then
1159 willCS = willCauseSpill (sym->nRegs, sym->regType);
1160 spillable = computeSpillable (ic);
1162 (willCS && bitVectIsZero (spillable)))
1165 D (D_ALLOC, ("serialRegAssign: \"remat spill\"\n"));
1171 /* if it has a spillocation & is used less than
1172 all other live ranges then spill this */
1174 if (sym->usl.spillLoc) {
1175 symbol *leastUsed = leastUsedLR (liveRangesWith (spillable,
1176 allLRs, ebbs[i], ic));
1177 if (leastUsed && leastUsed->used > sym->used) {
1182 /* if none of the liveRanges have a spillLocation then better
1183 to spill this one than anything else already assigned to registers */
1184 if (liveRangesWith(spillable,noSpilLoc,ebbs[i],ic)) {
1185 /* if this is local to this block then we might find a block spil */
1186 if (!(sym->liveFrom >= ebbs[i]->fSeq && sym->liveTo <= ebbs[i]->lSeq)) {
1194 /* else we assign registers to it */
1195 _G.regAssigned = bitVectSetBit (_G.regAssigned, sym->key);
1196 _G.totRegAssigned = bitVectSetBit (_G.totRegAssigned, sym->key);
1198 /* Special case: Try to fit into a reg pair if
1200 D (D_ALLOC, ("serialRegAssign: actually allocing regs!\n"));
1201 if ((sym->nRegs == 2) && tryAllocatingRegPair (sym))
1206 for (j = 0; j < sym->nRegs; j++)
1208 sym->regs[j] = getRegGpr (ic, ebbs[i], sym);
1210 /* if the allocation falied which means
1211 this was spilt then break */
1214 D (D_ALLOC, ("Couldnt alloc (spill)\n"))
1219 /* if it shares registers with operands make sure
1220 that they are in the same position */
1221 if (IC_LEFT (ic) && IS_SYMOP (IC_LEFT (ic)) &&
1222 OP_SYMBOL (IC_LEFT (ic))->nRegs && ic->op != '=')
1223 positionRegs (OP_SYMBOL (IC_RESULT (ic)),
1224 OP_SYMBOL (IC_LEFT (ic)));
1225 /* do the same for the right operand */
1226 if (IC_RIGHT (ic) && IS_SYMOP (IC_RIGHT (ic)) &&
1227 OP_SYMBOL (IC_RIGHT (ic))->nRegs)
1228 positionRegs (OP_SYMBOL (IC_RESULT (ic)),
1229 OP_SYMBOL (IC_RIGHT (ic)));
1235 /* Check for and fix any problems with uninitialized operands */
1236 for (i = 0; i < count; i++)
1240 if (ebbs[i]->noPath &&
1241 (ebbs[i]->entryLabel != entryLabel &&
1242 ebbs[i]->entryLabel != returnLabel))
1245 for (ic = ebbs[i]->sch; ic; ic = ic->next)
1252 verifyRegsAssigned (IC_COND (ic), ic);
1256 if (ic->op == JUMPTABLE)
1258 verifyRegsAssigned (IC_JTCOND (ic), ic);
1262 verifyRegsAssigned (IC_RESULT (ic), ic);
1263 verifyRegsAssigned (IC_LEFT (ic), ic);
1264 verifyRegsAssigned (IC_RIGHT (ic), ic);
1270 /*-----------------------------------------------------------------*/
1271 /* fillGaps - Try to fill in the Gaps left by Pass1 */
1272 /*-----------------------------------------------------------------*/
1273 static void fillGaps()
1278 if (getenv("DISABLE_FILL_GAPS")) return;
1280 /* look for livernages that was spilt by the allocator */
1281 for (sym = hTabFirstItem(liveRanges,&key) ; sym ;
1282 sym = hTabNextItem(liveRanges,&key)) {
1287 if (!sym->spillA || !sym->clashes || sym->remat) continue ;
1289 /* find the liveRanges this one clashes with, that are
1290 still assigned to registers & mark the registers as used*/
1291 for ( i = 0 ; i < sym->clashes->size ; i ++) {
1295 if (bitVectBitValue(sym->clashes,i) == 0 || /* those that clash with this */
1296 bitVectBitValue(_G.totRegAssigned,i) == 0) /* and are still assigned to registers */
1299 clr = hTabItemWithKey(liveRanges,i);
1302 /* mark these registers as used */
1303 for (k = 0 ; k < clr->nRegs ; k++ )
1304 useReg(clr->regs[k]);
1307 if (willCauseSpill(sym->nRegs,sym->regType)) {
1308 /* NOPE :( clear all registers & and continue */
1313 /* THERE IS HOPE !!!! */
1314 for (i=0; i < sym->nRegs ; i++ ) {
1315 sym->regs[i] = getRegGprNoSpil ();
1318 /* for all its definitions check if the registers
1319 allocated needs positioning NOTE: we can position
1320 only ONCE if more than One positioning required
1323 for (i = 0 ; i < sym->defs->size ; i++ ) {
1324 if (bitVectBitValue(sym->defs,i)) {
1326 if (!(ic = hTabItemWithKey(iCodehTab,i))) continue ;
1327 if (SKIP_IC(ic)) continue;
1328 assert(isSymbolEqual(sym,OP_SYMBOL(IC_RESULT(ic)))); /* just making sure */
1329 /* if left is assigned to registers */
1330 if (IS_SYMOP(IC_LEFT(ic)) &&
1331 bitVectBitValue(_G.totRegAssigned,OP_SYMBOL(IC_LEFT(ic))->key)) {
1332 pdone += positionRegs(sym,OP_SYMBOL(IC_LEFT(ic)));
1334 if (IS_SYMOP(IC_RIGHT(ic)) &&
1335 bitVectBitValue(_G.totRegAssigned,OP_SYMBOL(IC_RIGHT(ic))->key)) {
1336 pdone += positionRegs(sym,OP_SYMBOL(IC_RIGHT(ic)));
1338 if (pdone > 1) break;
1341 for (i = 0 ; i < sym->uses->size ; i++ ) {
1342 if (bitVectBitValue(sym->uses,i)) {
1344 if (!(ic = hTabItemWithKey(iCodehTab,i))) continue ;
1345 if (SKIP_IC(ic)) continue;
1346 if (!IS_ASSIGN_ICODE(ic)) continue ;
1348 /* if result is assigned to registers */
1349 if (IS_SYMOP(IC_RESULT(ic)) &&
1350 bitVectBitValue(_G.totRegAssigned,OP_SYMBOL(IC_RESULT(ic))->key)) {
1351 pdone += positionRegs(sym,OP_SYMBOL(IC_RESULT(ic)));
1353 if (pdone > 1) break;
1356 /* had to position more than once GIVE UP */
1358 /* UNDO all the changes we made to try this */
1360 for (i=0; i < sym->nRegs ; i++ ) {
1361 sym->regs[i] = NULL;
1364 D(D_FILL_GAPS,("Fill Gap gave up due to positioning for %s in function %s\n",sym->name, currFunc ? currFunc->name : "UNKNOWN"));
1367 D(D_FILL_GAPS,("FILLED GAP for %s in function %s\n",sym->name, currFunc ? currFunc->name : "UNKNOWN"));
1368 _G.totRegAssigned = bitVectSetBit(_G.totRegAssigned,sym->key);
1369 sym->isspilt = sym->spillA = 0 ;
1370 sym->usl.spillLoc->allocreq--;
1375 /*-----------------------------------------------------------------*/
1376 /* rUmaskForOp :- returns register mask for an operand */
1377 /*-----------------------------------------------------------------*/
1379 rUmaskForOp (operand * op)
1385 /* only temporaries are assigned registers */
1389 sym = OP_SYMBOL (op);
1391 /* if spilt or no registers assigned to it
1393 if (sym->isspilt || !sym->nRegs)
1396 rumask = newBitVect (_G.nRegs);
1398 for (j = 0; j < sym->nRegs; j++)
1400 rumask = bitVectSetBit (rumask, sym->regs[j]->rIdx);
1407 z80_rUmaskForOp (operand * op)
1409 return rUmaskForOp (op);
1412 /** Returns bit vector of registers used in iCode.
1415 regsUsedIniCode (iCode * ic)
1417 bitVect *rmask = newBitVect (_G.nRegs);
1419 /* do the special cases first */
1422 rmask = bitVectUnion (rmask,
1423 rUmaskForOp (IC_COND (ic)));
1427 /* for the jumptable */
1428 if (ic->op == JUMPTABLE)
1430 rmask = bitVectUnion (rmask,
1431 rUmaskForOp (IC_JTCOND (ic)));
1436 /* of all other cases */
1438 rmask = bitVectUnion (rmask,
1439 rUmaskForOp (IC_LEFT (ic)));
1443 rmask = bitVectUnion (rmask,
1444 rUmaskForOp (IC_RIGHT (ic)));
1447 rmask = bitVectUnion (rmask,
1448 rUmaskForOp (IC_RESULT (ic)));
1454 /** For each instruction will determine the regsUsed.
1457 createRegMask (eBBlock ** ebbs, int count)
1461 /* for all blocks */
1462 for (i = 0; i < count; i++)
1466 if (ebbs[i]->noPath &&
1467 (ebbs[i]->entryLabel != entryLabel &&
1468 ebbs[i]->entryLabel != returnLabel))
1471 /* for all instructions */
1472 for (ic = ebbs[i]->sch; ic; ic = ic->next)
1477 if (SKIP_IC2 (ic) || !ic->rlive)
1480 /* first mark the registers used in this
1482 ic->rUsed = regsUsedIniCode (ic);
1483 _G.funcrUsed = bitVectUnion (_G.funcrUsed, ic->rUsed);
1485 /* now create the register mask for those
1486 registers that are in use : this is a
1487 super set of ic->rUsed */
1488 ic->rMask = newBitVect (_G.nRegs + 1);
1490 /* for all live Ranges alive at this point */
1491 for (j = 1; j < ic->rlive->size; j++)
1496 /* if not alive then continue */
1497 if (!bitVectBitValue (ic->rlive, j))
1500 /* find the live range we are interested in */
1501 if (!(sym = hTabItemWithKey (liveRanges, j)))
1503 werror (E_INTERNAL_ERROR, __FILE__, __LINE__,
1504 "createRegMask cannot find live range");
1508 /* if no register assigned to it */
1509 if (!sym->nRegs || sym->isspilt)
1512 /* for all the registers allocated to it */
1513 for (k = 0; k < sym->nRegs; k++)
1516 bitVectSetBit (ic->rMask, sym->regs[k]->rIdx);
1522 /** Returns the rematerialized string for a remat var.
1525 rematStr (symbol * sym)
1528 iCode *ic = sym->rematiCode;
1533 /* if plus or minus print the right hand side */
1534 if (ic->op == '+' || ic->op == '-')
1536 sprintf (s, "0x%04x %c ", (int) operandLitValue (IC_RIGHT (ic)),
1539 ic = OP_SYMBOL (IC_LEFT (ic))->rematiCode;
1542 /* we reached the end */
1543 sprintf (s, "%s", OP_SYMBOL (IC_LEFT (ic))->rname);
1550 /*-----------------------------------------------------------------*/
1551 /* regTypeNum - computes the type & number of registers required */
1552 /*-----------------------------------------------------------------*/
1559 /* for each live range do */
1560 for (sym = hTabFirstItem (liveRanges, &k); sym;
1561 sym = hTabNextItem (liveRanges, &k))
1564 /* if used zero times then no registers needed */
1565 if ((sym->liveTo - sym->liveFrom) == 0)
1568 D (D_ALLOC, ("regTypeNum: loop on sym %p\n", sym));
1570 /* if the live range is a temporary */
1574 /* if the type is marked as a conditional */
1575 if (sym->regType == REG_CND)
1578 /* if used in return only then we don't
1580 if (sym->ruonly || sym->accuse)
1582 if (IS_AGGREGATE (sym->type) || sym->isptr)
1583 sym->type = aggrToPtr (sym->type, FALSE);
1587 /* if not then we require registers */
1588 D (D_ALLOC, ("regTypeNum: isagg %u nRegs %u type %p\n", IS_AGGREGATE (sym->type) || sym->isptr, sym->nRegs, sym->type));
1589 sym->nRegs = ((IS_AGGREGATE (sym->type) || sym->isptr) ?
1590 getSize (sym->type = aggrToPtr (sym->type, FALSE)) :
1591 getSize (sym->type));
1592 D (D_ALLOC, ("regTypeNum: setting nRegs of %s (%p) to %u\n", sym->name, sym, sym->nRegs));
1594 D (D_ALLOC, ("regTypeNum: setup to assign regs sym %p\n", sym));
1598 fprintf (stderr, "allocated more than 4 or 0 registers for type ");
1599 printTypeChain (sym->type, stderr);
1600 fprintf (stderr, "\n");
1603 /* determine the type of register required */
1604 /* Always general purpose */
1605 sym->regType = REG_GPR;
1610 /* for the first run we don't provide */
1611 /* registers for true symbols we will */
1612 /* see how things go */
1613 D (D_ALLOC, ("regTypeNum: #2 setting num of %p to 0\n", sym));
1620 /** Mark all registers as free.
1627 D (D_ALLOC, ("freeAllRegs: running.\n"));
1629 for (i = 0; i < _G.nRegs; i++)
1630 regsZ80[i].isFree = 1;
1633 /*-----------------------------------------------------------------*/
1634 /* deallocStackSpil - this will set the stack pointer back */
1635 /*-----------------------------------------------------------------*/
1636 DEFSETFUNC (deallocStackSpil)
1644 /** Register reduction for assignment.
1647 packRegsForAssign (iCode * ic, eBBlock * ebp)
1651 D (D_ALLOC, ("packRegsForAssign: running on ic %p\n", ic));
1653 if (!IS_ITEMP (IC_RIGHT (ic)) ||
1654 OP_SYMBOL (IC_RIGHT (ic))->isind ||
1655 OP_LIVETO (IC_RIGHT (ic)) > ic->seq)
1660 /* find the definition of iTempNN scanning backwards if we find a
1661 a use of the true symbol in before we find the definition then
1663 for (dic = ic->prev; dic; dic = dic->prev)
1665 /* PENDING: Don't pack across function calls. */
1666 if (dic->op == CALL || dic->op == PCALL)
1675 if (IS_SYMOP (IC_RESULT (dic)) &&
1676 IC_RESULT (dic)->key == IC_RIGHT (ic)->key)
1681 if (IS_SYMOP (IC_RIGHT (dic)) &&
1682 (IC_RIGHT (dic)->key == IC_RESULT (ic)->key ||
1683 IC_RIGHT (dic)->key == IC_RIGHT (ic)->key))
1689 if (IS_SYMOP (IC_LEFT (dic)) &&
1690 (IC_LEFT (dic)->key == IC_RESULT (ic)->key ||
1691 IC_LEFT (dic)->key == IC_RIGHT (ic)->key))
1699 return 0; /* did not find */
1701 /* if the result is on stack or iaccess then it must be
1702 the same atleast one of the operands */
1703 if (OP_SYMBOL (IC_RESULT (ic))->onStack ||
1704 OP_SYMBOL (IC_RESULT (ic))->iaccess)
1706 /* the operation has only one symbol
1707 operator then we can pack */
1708 if ((IC_LEFT (dic) && !IS_SYMOP (IC_LEFT (dic))) ||
1709 (IC_RIGHT (dic) && !IS_SYMOP (IC_RIGHT (dic))))
1712 if (!((IC_LEFT (dic) &&
1713 IC_RESULT (ic)->key == IC_LEFT (dic)->key) ||
1715 IC_RESULT (ic)->key == IC_RIGHT (dic)->key)))
1719 /* found the definition */
1720 /* replace the result with the result of */
1721 /* this assignment and remove this assignment */
1722 bitVectUnSetBit(OP_SYMBOL(IC_RESULT(dic))->defs,dic->key);
1723 IC_RESULT (dic) = IC_RESULT (ic);
1725 if (IS_ITEMP (IC_RESULT (dic)) && OP_SYMBOL (IC_RESULT (dic))->liveFrom > dic->seq)
1727 OP_SYMBOL (IC_RESULT (dic))->liveFrom = dic->seq;
1729 /* delete from liverange table also
1730 delete from all the points inbetween and the new
1732 for (sic = dic; sic != ic; sic = sic->next)
1734 bitVectUnSetBit (sic->rlive, IC_RESULT (ic)->key);
1735 if (IS_ITEMP (IC_RESULT (dic)))
1736 bitVectSetBit (sic->rlive, IC_RESULT (dic)->key);
1739 remiCodeFromeBBlock (ebp, ic);
1740 // PENDING: Check vs mcs51
1741 bitVectUnSetBit(OP_SYMBOL(IC_RESULT(ic))->defs,ic->key);
1742 hTabDeleteItem (&iCodehTab, ic->key, ic, DELETE_ITEM, NULL);
1743 OP_DEFS(IC_RESULT (dic))=bitVectSetBit (OP_DEFS (IC_RESULT (dic)), dic->key);
1747 /** Scanning backwards looks for first assig found.
1750 findAssignToSym (operand * op, iCode * ic)
1754 for (dic = ic->prev; dic; dic = dic->prev)
1757 /* if definition by assignment */
1758 if (dic->op == '=' &&
1759 !POINTER_SET (dic) &&
1760 IC_RESULT (dic)->key == op->key)
1761 /* && IS_TRUE_SYMOP(IC_RIGHT(dic)) */
1764 /* we are interested only if defined in far space */
1765 /* or in stack space in case of + & - */
1767 /* if assigned to a non-symbol then return
1769 if (!IS_SYMOP (IC_RIGHT (dic)))
1772 /* if the symbol is in far space then
1774 if (isOperandInFarSpace (IC_RIGHT (dic)))
1777 /* for + & - operations make sure that
1778 if it is on the stack it is the same
1779 as one of the three operands */
1780 if ((ic->op == '+' || ic->op == '-') &&
1781 OP_SYMBOL (IC_RIGHT (dic))->onStack)
1784 if (IC_RESULT (ic)->key != IC_RIGHT (dic)->key &&
1785 IC_LEFT (ic)->key != IC_RIGHT (dic)->key &&
1786 IC_RIGHT (ic)->key != IC_RIGHT (dic)->key)
1794 /* if we find an usage then we cannot delete it */
1795 if (IC_LEFT (dic) && IC_LEFT (dic)->key == op->key)
1798 if (IC_RIGHT (dic) && IC_RIGHT (dic)->key == op->key)
1801 if (POINTER_SET (dic) && IC_RESULT (dic)->key == op->key)
1805 /* now make sure that the right side of dic
1806 is not defined between ic & dic */
1809 iCode *sic = dic->next;
1811 for (; sic != ic; sic = sic->next)
1812 if (IC_RESULT (sic) &&
1813 IC_RESULT (sic)->key == IC_RIGHT (dic)->key)
1822 #if !DISABLE_PACKREGSFORSUPPORT
1825 /*-----------------------------------------------------------------*/
1826 /* packRegsForSupport :- reduce some registers for support calls */
1827 /*-----------------------------------------------------------------*/
1829 packRegsForSupport (iCode * ic, eBBlock * ebp)
1832 /* for the left & right operand :- look to see if the
1833 left was assigned a true symbol in far space in that
1834 case replace them */
1835 D (D_ALLOC, ("packRegsForSupport: running on ic %p\n", ic));
1837 if (IS_ITEMP (IC_LEFT (ic)) &&
1838 OP_SYMBOL (IC_LEFT (ic))->liveTo <= ic->seq)
1840 iCode *dic = findAssignToSym (IC_LEFT (ic), ic);
1846 /* found it we need to remove it from the
1848 for (sic = dic; sic != ic; sic = sic->next)
1849 bitVectUnSetBit (sic->rlive, IC_LEFT (ic)->key);
1851 IC_LEFT (ic)->operand.symOperand =
1852 IC_RIGHT (dic)->operand.symOperand;
1853 IC_LEFT (ic)->key = IC_RIGHT (dic)->operand.symOperand->key;
1854 remiCodeFromeBBlock (ebp, dic);
1855 bitVectUnSetBit(OP_SYMBOL(IC_RESULT(dic))->defs,dic->key);
1856 hTabDeleteItem (&iCodehTab, dic->key, dic, DELETE_ITEM, NULL);
1857 // PENDING: Check vs mcs51
1861 /* do the same for the right operand */
1864 IS_ITEMP (IC_RIGHT (ic)) &&
1865 OP_SYMBOL (IC_RIGHT (ic))->liveTo <= ic->seq)
1867 iCode *dic = findAssignToSym (IC_RIGHT (ic), ic);
1873 /* found it we need to remove it from the block */
1874 for (sic = dic; sic != ic; sic = sic->next)
1875 bitVectUnSetBit (sic->rlive, IC_RIGHT (ic)->key);
1877 IC_RIGHT (ic)->operand.symOperand =
1878 IC_RIGHT (dic)->operand.symOperand;
1879 IC_RIGHT (ic)->key = IC_RIGHT (dic)->operand.symOperand->key;
1881 remiCodeFromeBBlock (ebp, dic);
1882 bitVectUnSetBit(OP_SYMBOL(IC_RESULT(dic))->defs,dic->key);
1883 hTabDeleteItem (&iCodehTab, dic->key, dic, DELETE_ITEM, NULL);
1884 // PENDING: vs mcs51
1892 #define IS_OP_RUONLY(x) (x && IS_SYMOP(x) && OP_SYMBOL(x)->ruonly)
1894 /** Will reduce some registers for single use.
1897 packRegsForOneuse (iCode * ic, operand * op, eBBlock * ebp)
1903 D (D_ALLOC, ("packRegsForOneUse: running on ic %p\n", ic));
1905 /* if returning a literal then do nothing */
1909 /* only upto 2 bytes since we cannot predict
1910 the usage of b, & acc */
1911 if (getSize (operandType (op)) > 2)
1914 if (ic->op != RETURN &&
1918 /* this routine will mark the a symbol as used in one
1919 instruction use only && if the defintion is local
1920 (ie. within the basic block) && has only one definition &&
1921 that definiion is either a return value from a
1922 function or does not contain any variables in
1924 uses = bitVectCopy (OP_USES (op));
1925 bitVectUnSetBit (uses, ic->key); /* take away this iCode */
1926 if (!bitVectIsZero (uses)) /* has other uses */
1929 /* if it has only one defintion */
1930 if (bitVectnBitsOn (OP_DEFS (op)) > 1)
1931 return NULL; /* has more than one definition */
1933 /* get the that definition */
1935 hTabItemWithKey (iCodehTab,
1936 bitVectFirstBit (OP_DEFS (op)))))
1939 /* found the definition now check if it is local */
1940 if (dic->seq < ebp->fSeq ||
1941 dic->seq > ebp->lSeq)
1942 return NULL; /* non-local */
1944 /* now check if it is the return from a function call */
1945 if (dic->op == CALL || dic->op == PCALL)
1947 if (ic->op != SEND && ic->op != RETURN &&
1948 !POINTER_SET(ic) && !POINTER_GET(ic))
1950 OP_SYMBOL (op)->ruonly = 1;
1956 /* otherwise check that the definition does
1957 not contain any symbols in far space */
1958 if (isOperandInFarSpace (IC_LEFT (dic)) ||
1959 isOperandInFarSpace (IC_RIGHT (dic)) ||
1960 IS_OP_RUONLY (IC_LEFT (ic)) ||
1961 IS_OP_RUONLY (IC_RIGHT (ic)))
1966 /* if pointer set then make sure the pointer is one byte */
1967 if (POINTER_SET (dic))
1970 if (POINTER_GET (dic))
1975 /* also make sure the intervenening instructions
1976 don't have any thing in far space */
1977 for (dic = dic->next; dic && dic != ic; dic = dic->next)
1979 /* if there is an intervening function call then no */
1980 if (dic->op == CALL || dic->op == PCALL)
1982 /* if pointer set then make sure the pointer
1984 if (POINTER_SET (dic))
1987 if (POINTER_GET (dic))
1990 /* if address of & the result is remat the okay */
1991 if (dic->op == ADDRESS_OF &&
1992 OP_SYMBOL (IC_RESULT (dic))->remat)
1995 /* if left or right or result is in far space */
1996 if (isOperandInFarSpace (IC_LEFT (dic)) ||
1997 isOperandInFarSpace (IC_RIGHT (dic)) ||
1998 isOperandInFarSpace (IC_RESULT (dic)) ||
1999 IS_OP_RUONLY (IC_LEFT (dic)) ||
2000 IS_OP_RUONLY (IC_RIGHT (dic)) ||
2001 IS_OP_RUONLY (IC_RESULT (dic)))
2007 OP_SYMBOL (op)->ruonly = 1;
2011 /*-----------------------------------------------------------------*/
2012 /* isBitwiseOptimizable - requirements of JEAN LOUIS VERN */
2013 /*-----------------------------------------------------------------*/
2015 isBitwiseOptimizable (iCode * ic)
2017 sym_link *rtype = getSpec (operandType (IC_RIGHT (ic)));
2019 /* bitwise operations are considered optimizable
2020 under the following conditions (Jean-Louis VERN)
2032 if (IS_LITERAL (rtype))
2038 Certian assignments involving pointers can be temporarly stored
2049 #if !DISABLE_PACKREGSFORACCUSE
2052 /** Pack registers for acc use.
2053 When the result of this operation is small and short lived it may
2054 be able to be stored in the accumelator.
2057 packRegsForAccUse (iCode * ic)
2061 /* if this is an aggregate, e.g. a one byte char array */
2062 if (IS_AGGREGATE(operandType(IC_RESULT(ic)))) {
2066 /* if + or - then it has to be one byte result */
2067 if ((ic->op == '+' || ic->op == '-')
2068 && getSize (operandType (IC_RESULT (ic))) > 1)
2071 /* if shift operation make sure right side is not a literal */
2072 if (ic->op == RIGHT_OP &&
2073 (isOperandLiteral (IC_RIGHT (ic)) ||
2074 getSize (operandType (IC_RESULT (ic))) > 1))
2077 if (ic->op == LEFT_OP &&
2078 (isOperandLiteral (IC_RIGHT (ic)) ||
2079 getSize (operandType (IC_RESULT (ic))) > 1))
2082 /* has only one definition */
2083 if (bitVectnBitsOn (OP_DEFS (IC_RESULT (ic))) > 1)
2086 /* has only one use */
2087 if (bitVectnBitsOn (OP_USES (IC_RESULT (ic))) > 1)
2090 /* and the usage immediately follows this iCode */
2091 if (!(uic = hTabItemWithKey (iCodehTab,
2092 bitVectFirstBit (OP_USES (IC_RESULT (ic))))))
2095 if (ic->next != uic)
2098 /* if it is a conditional branch then we definitely can */
2102 if (uic->op == JUMPTABLE)
2106 /* if the usage is not is an assignment or an
2107 arithmetic / bitwise / shift operation then not */
2108 if (POINTER_SET (uic) &&
2109 getSize (aggrToPtr (operandType (IC_RESULT (uic)), FALSE)) > 1)
2113 if (uic->op != '=' &&
2114 !IS_ARITHMETIC_OP (uic) &&
2115 !IS_BITWISE_OP (uic) &&
2116 uic->op != LEFT_OP &&
2117 uic->op != RIGHT_OP)
2120 /* if used in ^ operation then make sure right is not a
2122 if (uic->op == '^' && isOperandLiteral (IC_RIGHT (uic)))
2125 /* if shift operation make sure right side is not a literal */
2126 if (uic->op == RIGHT_OP &&
2127 (isOperandLiteral (IC_RIGHT (uic)) ||
2128 getSize (operandType (IC_RESULT (uic))) > 1))
2131 if (uic->op == LEFT_OP &&
2132 (isOperandLiteral (IC_RIGHT (uic)) ||
2133 getSize (operandType (IC_RESULT (uic))) > 1))
2137 /* make sure that the result of this icode is not on the
2138 stack, since acc is used to compute stack offset */
2139 if (IS_TRUE_SYMOP (IC_RESULT (uic)) &&
2140 OP_SYMBOL (IC_RESULT (uic))->onStack)
2145 /* if either one of them in far space then we cannot */
2146 if ((IS_TRUE_SYMOP (IC_LEFT (uic)) &&
2147 isOperandInFarSpace (IC_LEFT (uic))) ||
2148 (IS_TRUE_SYMOP (IC_RIGHT (uic)) &&
2149 isOperandInFarSpace (IC_RIGHT (uic))))
2153 /* if the usage has only one operand then we can */
2154 if (IC_LEFT (uic) == NULL ||
2155 IC_RIGHT (uic) == NULL)
2158 /* make sure this is on the left side if not
2159 a '+' since '+' is commutative */
2160 if (ic->op != '+' &&
2161 IC_LEFT (uic)->key != IC_RESULT (ic)->key)
2164 // See mcs51 ralloc for reasoning
2166 /* if one of them is a literal then we can */
2167 if ((IC_LEFT (uic) && IS_OP_LITERAL (IC_LEFT (uic))) ||
2168 (IC_RIGHT (uic) && IS_OP_LITERAL (IC_RIGHT (uic))))
2175 /** This is confusing :) Guess for now */
2176 if (IC_LEFT (uic)->key == IC_RESULT (ic)->key &&
2177 (IS_ITEMP (IC_RIGHT (uic)) ||
2178 (IS_TRUE_SYMOP (IC_RIGHT (uic)))))
2181 if (IC_RIGHT (uic)->key == IC_RESULT (ic)->key &&
2182 (IS_ITEMP (IC_LEFT (uic)) ||
2183 (IS_TRUE_SYMOP (IC_LEFT (uic)))))
2187 OP_SYMBOL (IC_RESULT (ic))->accuse = ACCUSE_A;
2192 packRegsForHLUse (iCode * ic)
2196 /* PENDING: Could do IFX */
2202 /* has only one definition */
2203 if (bitVectnBitsOn (OP_DEFS (IC_RESULT (ic))) > 1)
2205 D (D_HLUSE, (" + Dropping as has more than one def\n"));
2209 /* has only one use */
2210 if (bitVectnBitsOn (OP_USES (IC_RESULT (ic))) > 1)
2212 D (D_HLUSE, (" + Dropping as has more than one use\n"));
2216 /* and the usage immediately follows this iCode */
2217 if (!(uic = hTabItemWithKey (iCodehTab,
2218 bitVectFirstBit (OP_USES (IC_RESULT (ic))))))
2220 D (D_HLUSE, (" + Dropping as usage isn't in this block\n"));
2224 if (ic->next != uic)
2226 D (D_HLUSE, (" + Dropping as usage doesn't follow this\n"));
2235 if (getSize (operandType (IC_RESULT (ic))) != 2 ||
2236 (IC_LEFT(uic) && getSize (operandType (IC_LEFT (uic))) != 2) ||
2237 (IC_RIGHT(uic) && getSize (operandType (IC_RIGHT (uic))) != 2))
2239 D (D_HLUSE, (" + Dropping as the result size is not 2\n"));
2245 if (ic->op == CAST && uic->op == IPUSH)
2247 if (ic->op == ADDRESS_OF && uic->op == IPUSH)
2249 if (ic->op == ADDRESS_OF && POINTER_GET (uic) && IS_ITEMP( IC_RESULT (uic)))
2251 if (ic->op == CALL && ic->parmBytes == 0 && (uic->op == '-' || uic->op == '+'))
2256 /* Case of assign a constant to offset in a static array. */
2257 if (ic->op == '+' && IS_VALOP (IC_RIGHT (ic)))
2259 if (uic->op == '=' && POINTER_SET (uic))
2263 else if (uic->op == IPUSH && getSize (operandType (IC_LEFT (uic))) == 2)
2270 D (D_HLUSE, (" + Dropping as it's a bad op\n"));
2273 OP_SYMBOL (IC_RESULT (ic))->accuse = ACCUSE_SCRATCH;
2277 packRegsForHLUse3 (iCode * lic, operand * op, eBBlock * ebp)
2282 bool isFirst = TRUE;
2284 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));
2288 if ( OP_SYMBOL(op)->accuse)
2293 if (OP_SYMBOL(op)->remat)
2298 /* Only defined once */
2299 if (bitVectnBitsOn (OP_DEFS (op)) > 1)
2302 if (getSize (operandType (op)) > 2)
2305 /* And this is the definition */
2306 if (bitVectFirstBit (OP_DEFS (op)) != lic->key)
2309 /* first check if any overlapping liverange has already been
2311 if (OP_SYMBOL(op)->clashes)
2313 for (i = 0 ; i < OP_SYMBOL(op)->clashes->size ; i++ )
2315 if (bitVectBitValue(OP_SYMBOL(op)->clashes,i))
2317 sym = hTabItemWithKey(liveRanges,i);
2318 if (sym->accuse == ACCUSE_SCRATCH)
2326 /* Nothing else that clashes with this is using the scratch
2327 register. Scan through all of the intermediate instructions and
2328 see if any of them could nuke HL.
2330 dic = ic = hTabFirstItemWK(iCodeSeqhTab,OP_SYMBOL(op)->liveFrom);
2332 for (; ic && ic->seq <= OP_SYMBOL(op)->liveTo;
2333 ic = hTabNextItem(iCodeSeqhTab, &key))
2337 D (D_PACK_HLUSE3, ("(On %p: op: %u next: %p)\n", ic, ic->op, ic->next));
2342 if (ic->op == ADDRESS_OF)
2344 if (POINTER_GET (ic))
2346 if (ic->op == '=' && !POINTER_SET(ic))
2350 if (IC_RESULT(ic) && IS_SYMOP(IC_RESULT(ic))
2351 && isOperandInDirSpace (IC_RESULT (ic)))
2354 if (IC_LEFT(ic) && IS_SYMOP(IC_LEFT(ic))
2355 && isOperandInDirSpace (IC_LEFT (ic)))
2358 if (IC_RIGHT(ic) && IS_SYMOP(IC_RIGHT(ic))
2359 && isOperandInDirSpace (IC_RIGHT (ic)))
2362 /* Handle the non left/right/result ones first */
2365 if (ic->op == JUMPTABLE)
2374 if (ic->op == IPUSH && isOperandEqual (op, IC_LEFT (ic)))
2377 if (ic->op == SEND && isOperandEqual (op, IC_LEFT (ic)))
2380 if (ic->op == CALL && isOperandEqual (op, IC_RESULT (ic)))
2383 if (ic->op == LEFT_OP && isOperandLiteral (IC_RIGHT (ic)))
2386 if ((ic->op == '=' && !POINTER_SET(ic)) ||
2387 ic->op == UNARYMINUS ||
2396 if (ic->op == '*' && isOperandEqual (op, IC_LEFT (ic)))
2399 if (POINTER_SET (ic) && isOperandEqual (op, IC_RESULT (ic)))
2402 if (POINTER_GET (ic) && isOperandEqual (op, IC_LEFT (ic)))
2405 if (IS_VALOP (IC_RIGHT (ic)) &&
2412 /* By default give up */
2416 D (D_PACK_HLUSE3, ("Succeeded!\n"))
2418 OP_SYMBOL (op)->accuse = ACCUSE_SCRATCH;
2423 packRegsForIYUse (iCode * lic, operand * op, eBBlock * ebp)
2430 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));
2434 if ( OP_SYMBOL(op)->accuse)
2439 if (OP_SYMBOL(op)->remat)
2444 /* Only defined once */
2445 if (bitVectnBitsOn (OP_DEFS (op)) > 1)
2448 /* And this is the definition */
2449 if (bitVectFirstBit (OP_DEFS (op)) != lic->key)
2452 /* first check if any overlapping liverange has already been
2454 if (OP_SYMBOL(op)->clashes)
2456 for (i = 0 ; i < OP_SYMBOL(op)->clashes->size ; i++ )
2458 if (bitVectBitValue(OP_SYMBOL(op)->clashes,i))
2460 sym = hTabItemWithKey(liveRanges,i);
2461 if (sym->accuse == ACCUSE_IY)
2469 /* Only a few instructions can load into IY */
2475 if (getSize (operandType (op)) != 2)
2477 D (D_ACCUSE2, (" + Dropping as operation has size is too big\n"));
2481 /* Nothing else that clashes with this is using the scratch
2482 register. Scan through all of the intermediate instructions and
2483 see if any of them could nuke HL.
2485 dic = ic = hTabFirstItemWK(iCodeSeqhTab,OP_SYMBOL(op)->liveFrom);
2488 for (; ic && ic->seq <= OP_SYMBOL(op)->liveTo;
2489 ic = hTabNextItem(iCodeSeqhTab,&key))
2494 if (ic->op == PCALL ||
2503 /* Be pessamistic. */
2507 D (D_PACK_IY, (" op: %u uses %u result: %d left: %d right: %d\n", ic->op, bitVectBitValue(uses, ic->key),
2508 IC_RESULT(ic) && IS_SYMOP(IC_RESULT(ic)) ? isOperandInDirSpace(IC_RESULT(ic)) : -1,
2509 IC_LEFT(ic) && IS_SYMOP(IC_LEFT(ic)) ? isOperandInDirSpace(IC_LEFT(ic)) : -1,
2510 IC_RIGHT(ic) && IS_SYMOP(IC_RIGHT(ic)) ? isOperandInDirSpace(IC_RIGHT(ic)) : -1
2513 if (IC_RESULT(ic) && IS_SYMOP(IC_RESULT(ic)) &&
2514 isOperandInDirSpace(IC_RESULT(ic)))
2517 if (IC_RIGHT(ic) && IS_SYMOP(IC_RIGHT(ic)) &&
2518 isOperandInDirSpace(IC_RIGHT(ic)))
2521 if (IC_LEFT(ic) && IS_SYMOP(IC_LEFT(ic)) &&
2522 isOperandInDirSpace(IC_LEFT(ic)))
2525 /* Only certain rules will work against IY. Check if this iCode uses
2527 if (bitVectBitValue(uses, ic->key) != 0)
2529 if (ic->op == '=' &&
2530 isOperandEqual(IC_RESULT(ic), op))
2533 if (ic->op == GET_VALUE_AT_ADDRESS &&
2534 isOperandEqual(IC_LEFT(ic), op))
2537 if (isOperandEqual(IC_RESULT(ic), IC_LEFT(ic)) == FALSE)
2540 if (IC_RIGHT (ic) && IS_VALOP (IC_RIGHT (ic)))
2542 if (ic->op == '+' ||
2545 /* Only works if the constant is small */
2546 if (operandLitValue (IC_RIGHT (ic)) < 4)
2555 /* This iCode doesn't use the sym. See if this iCode preserves IY.
2560 /* By default give up */
2564 D (D_PACK_IY, ("Succeeded IY!\n"));
2566 OP_SYMBOL (op)->accuse = ACCUSE_IY;
2570 /** Returns TRUE if this operation can use acc and if it preserves the value.
2573 opPreservesA (iCode * uic)
2577 /* If we've gotten this far then the thing to compare must be
2578 small enough and must be in A.
2583 if (uic->op == JUMPTABLE)
2585 D (D_ACCUSE2, (" + Dropping as operation is a Jumptable\n"));
2589 /* A pointer assign preserves A if A is the left value. */
2590 if (uic->op == '=' && POINTER_SET (uic))
2595 /* if the usage has only one operand then we can */
2596 /* PENDING: check */
2597 if (IC_LEFT (uic) == NULL ||
2598 IC_RIGHT (uic) == NULL)
2600 D (D_ACCUSE2, (" + Dropping as operation has only one operand\n"));
2604 /* PENDING: check this rule */
2605 if (getSize (operandType (IC_RESULT (uic))) > 1)
2607 D (D_ACCUSE2, (" + Dropping as operation has size is too big\n"));
2612 /* Disabled all of the old rules as they weren't verified and have
2613 caused at least one problem.
2618 /** Returns true if this operand preserves the value of A.
2621 opIgnoresA (iCode * ic, iCode * uic)
2623 /* A increment of an iTemp by a constant is OK. */
2624 if ( uic->op == '+' &&
2625 IS_ITEMP (IC_LEFT (uic)) &&
2626 IS_ITEMP (IC_RESULT (uic)) &&
2627 IS_OP_LITERAL (IC_RIGHT (uic)))
2629 unsigned int icount = (unsigned int) floatFromVal (IC_RIGHT (uic)->operand.valOperand);
2631 /* Being an ITEMP means that we're already a symbol. */
2633 IC_RESULT (uic)->operand.symOperand->key == IC_LEFT (uic)->operand.symOperand->key
2639 else if (uic->op == '=' && !POINTER_SET (uic))
2641 /* If they are equal and get optimised out then things are OK. */
2642 if (isOperandEqual (IC_RESULT (uic), IC_RIGHT (uic)))
2644 /* Straight assign is OK. */
2653 /* Some optimisation cases:
2665 ; genAssign (pointer)
2669 want to optimise down to:
2675 So genPointer get is OK
2676 genPlus where the right is constant, left is iTemp, and result is same as left
2677 genAssign (pointer) is OK
2688 ; genAssign (pointer)
2689 ; AOP_STK for _strcpy_to_1_1
2694 want to optimise down to:
2700 So genIfx where IC_COND has size of 1 and is a constant.
2703 /** Pack registers for acc use.
2704 When the result of this operation is small and short lived it may
2705 be able to be stored in the accumulator.
2707 Note that the 'A preserving' list is currently emperical :)
2710 packRegsForAccUse2 (iCode * ic)
2714 D (D_ACCUSE2, ("packRegsForAccUse2: running on ic %p line %u\n", ic, ic->lineno));
2718 /* Filter out all but those 'good' commands */
2720 !POINTER_GET (ic) &&
2723 !IS_BITWISE_OP (ic) &&
2729 ic->op != GETHBIT &&
2732 D (D_ACCUSE2, (" + Dropping as not a 'good' source command\n"));
2736 /* if + or - then it has to be one byte result.
2739 if ((ic->op == '+' || ic->op == '-')
2740 && getSize (operandType (IC_RESULT (ic))) > 1)
2742 D (D_ACCUSE2, (" + Dropping as it's a big + or -\n"));
2746 /* has only one definition */
2747 if (bitVectnBitsOn (OP_DEFS (IC_RESULT (ic))) > 1)
2749 D (D_ACCUSE2, (" + Dropping as it has more than one definition\n"));
2753 /* Right. We may be able to propagate it through if:
2754 For each in the chain of uses the intermediate is OK.
2756 /* Get next with 'uses result' bit on
2757 If this->next == next
2758 Validate use of next
2759 If OK, increase count
2761 /* and the usage immediately follows this iCode */
2762 if (!(uic = hTabItemWithKey (iCodehTab,
2763 bitVectFirstBit (OP_USES (IC_RESULT (ic))))))
2765 D (D_ACCUSE2, (" + Dropping as usage does not follow first\n"));
2770 /* Create a copy of the OP_USES bit vect */
2771 bitVect *uses = bitVectCopy (OP_USES (IC_RESULT (ic)));
2773 iCode *scan = ic, *next;
2777 setBit = bitVectFirstBit (uses);
2778 next = hTabItemWithKey (iCodehTab, setBit);
2779 if (scan->next == next)
2781 D (D_ACCUSE2_VERBOSE, (" ! Is next in line\n"));
2783 bitVectUnSetBit (uses, setBit);
2784 /* Still contigous. */
2785 if (!opPreservesA (next))
2787 D (D_ACCUSE2, (" + Dropping as operation doesn't preserve A\n"));
2790 D (D_ACCUSE2_VERBOSE, (" ! Preserves A, so continue scanning\n"));
2793 else if (scan->next == NULL && bitVectnBitsOn (uses) == 1 && next != NULL)
2795 if (next->prev == NULL)
2797 if (!opPreservesA (next))
2799 D (D_ACCUSE2, (" + Dropping as operation doesn't preserve A #2\n"));
2802 bitVectUnSetBit (uses, setBit);
2807 D (D_ACCUSE2, (" + Dropping as last in list and next doesn't start a block\n"));
2811 else if (scan->next == NULL)
2813 D (D_ACCUSE2, (" + Dropping as hit the end of the list\n"));
2814 D (D_ACCUSE2, (" + Next in htab: %p\n", next));
2819 if (opIgnoresA (ic, scan->next))
2823 D (D_ACCUSE2_VERBOSE, (" ! Op ignores A, so continue scanning\n"));
2827 D (D_ACCUSE2, (" + Dropping as parts are not consecuitive and intermediate might use A\n"));
2832 while (!bitVectIsZero (uses));
2834 OP_SYMBOL (IC_RESULT (ic))->accuse = ACCUSE_A;
2839 /** Does some transformations to reduce register pressure.
2842 packRegisters (eBBlock * ebp)
2847 D (D_ALLOC, ("packRegisters: entered.\n"));
2849 while (1 && !DISABLE_PACK_ASSIGN)
2852 /* look for assignments of the form */
2853 /* iTempNN = TRueSym (someoperation) SomeOperand */
2855 /* TrueSym := iTempNN:1 */
2856 for (ic = ebp->sch; ic; ic = ic->next)
2858 /* find assignment of the form TrueSym := iTempNN:1 */
2859 if (ic->op == '=' && !POINTER_SET (ic))
2860 change += packRegsForAssign (ic, ebp);
2866 for (ic = ebp->sch; ic; ic = ic->next)
2868 /* Safe: address of a true sym is always constant. */
2869 /* if this is an itemp & result of a address of a true sym
2870 then mark this as rematerialisable */
2871 D (D_ALLOC, ("packRegisters: looping on ic %p\n", ic));
2873 if (ic->op == ADDRESS_OF &&
2874 IS_ITEMP (IC_RESULT (ic)) &&
2875 IS_TRUE_SYMOP (IC_LEFT (ic)) &&
2876 bitVectnBitsOn (OP_DEFS (IC_RESULT (ic))) == 1 &&
2877 !OP_SYMBOL (IC_LEFT (ic))->onStack)
2880 OP_SYMBOL (IC_RESULT (ic))->remat = 1;
2881 OP_SYMBOL (IC_RESULT (ic))->rematiCode = ic;
2882 OP_SYMBOL (IC_RESULT (ic))->usl.spillLoc = NULL;
2885 /* Safe: just propagates the remat flag */
2886 /* if straight assignment then carry remat flag if this is the
2888 if (ic->op == '=' &&
2889 !POINTER_SET (ic) &&
2890 IS_SYMOP (IC_RIGHT (ic)) &&
2891 OP_SYMBOL (IC_RIGHT (ic))->remat &&
2892 bitVectnBitsOn (OP_SYMBOL (IC_RESULT (ic))->defs) <= 1)
2895 OP_SYMBOL (IC_RESULT (ic))->remat =
2896 OP_SYMBOL (IC_RIGHT (ic))->remat;
2897 OP_SYMBOL (IC_RESULT (ic))->rematiCode =
2898 OP_SYMBOL (IC_RIGHT (ic))->rematiCode;
2901 /* if the condition of an if instruction is defined in the
2902 previous instruction then mark the itemp as a conditional */
2903 if ((IS_CONDITIONAL (ic) ||
2904 ((ic->op == BITWISEAND ||
2907 isBitwiseOptimizable (ic))) &&
2908 ic->next && ic->next->op == IFX &&
2909 bitVectnBitsOn (OP_USES(IC_RESULT(ic)))==1 &&
2910 isOperandEqual (IC_RESULT (ic), IC_COND (ic->next)) &&
2911 OP_SYMBOL (IC_RESULT (ic))->liveTo <= ic->next->seq)
2914 OP_SYMBOL (IC_RESULT (ic))->regType = REG_CND;
2919 /* reduce for support function calls */
2920 if (ic->supportRtn || ic->op == '+' || ic->op == '-')
2921 packRegsForSupport (ic, ebp);
2924 /* some cases the redundant moves can
2925 can be eliminated for return statements */
2926 if (ic->op == RETURN || ic->op == SEND)
2928 packRegsForOneuse (ic, IC_LEFT (ic), ebp);
2931 /* if pointer set & left has a size more than
2932 one and right is not in far space */
2933 if (!DISABLE_PACK_ONE_USE &&
2935 /* MLH: no such thing.
2936 !isOperandInFarSpace(IC_RIGHT(ic)) && */
2937 !OP_SYMBOL (IC_RESULT (ic))->remat &&
2938 !IS_OP_RUONLY (IC_RIGHT (ic)) &&
2939 getSize (aggrToPtr (operandType (IC_RESULT (ic)), FALSE)) > 1)
2942 packRegsForOneuse (ic, IC_RESULT (ic), ebp);
2945 /* if pointer get */
2946 if (!DISABLE_PACK_ONE_USE &&
2948 IS_SYMOP (IC_LEFT (ic)) &&
2949 /* MLH: dont have far space
2950 !isOperandInFarSpace(IC_RESULT(ic))&& */
2951 !OP_SYMBOL (IC_LEFT (ic))->remat &&
2952 !IS_OP_RUONLY (IC_RESULT (ic)) &&
2953 getSize (aggrToPtr (operandType (IC_LEFT (ic)), FALSE)) > 1)
2956 packRegsForOneuse (ic, IC_LEFT (ic), ebp);
2959 /* pack registers for accumulator use, when the result of an
2960 arithmetic or bit wise operation has only one use, that use is
2961 immediately following the defintion and the using iCode has
2962 only one operand or has two operands but one is literal & the
2963 result of that operation is not on stack then we can leave the
2964 result of this operation in acc:b combination */
2966 if (!DISABLE_PACK_HL && IS_ITEMP (IC_RESULT (ic)))
2972 packRegsForHLUse (ic);
2976 packRegsForHLUse3 (ic, IC_RESULT (ic), ebp);
2980 if (!DISABLE_PACK_IY && IS_ITEMP (IC_RESULT (ic)) && IS_Z80)
2982 packRegsForIYUse (ic, IC_RESULT (ic), ebp);
2985 if (!DISABLE_PACK_ACC && IS_ITEMP (IC_RESULT (ic)) &&
2986 getSize (operandType (IC_RESULT (ic))) == 1)
2988 packRegsForAccUse2 (ic);
2993 /** Joins together two byte constant pushes into one word push.
2996 joinPushes (iCode *lic)
3000 for (ic = lic; ic; ic = ic->next)
3007 /* Anything past this? */
3012 /* This and the next pushes? */
3013 if (ic->op != IPUSH || uic->op != IPUSH)
3017 /* Both literals? */
3018 if ( !IS_OP_LITERAL (IC_LEFT (ic)) || !IS_OP_LITERAL (IC_LEFT (uic)))
3022 /* Both characters? */
3023 if ( getSize (operandType (IC_LEFT (ic))) != 1 || getSize (operandType (IC_LEFT (uic))) != 1)
3027 /* Pull out the values, make a new type, and create the new iCode for it.
3029 first = (int)operandLitValue ( IC_LEFT (ic));
3030 second = (int)operandLitValue ( IC_LEFT (uic));
3032 sprintf (buffer, "%uu", ((first << 8) | (second & 0xFF)) & 0xFFFFU);
3033 val = constVal (buffer);
3034 SPEC_NOUN (val->type) = V_INT;
3035 IC_LEFT (ic) = operandFromOperand (IC_LEFT (ic));
3036 IC_LEFT (ic)->operand.valOperand = val;
3038 /* Now remove the second one from the list. */
3039 ic->next = uic->next;
3042 /* Patch up the reverse link */
3043 uic->next->prev = ic;
3050 /*-----------------------------------------------------------------*/
3051 /* assignRegisters - assigns registers to each live range as need */
3052 /*-----------------------------------------------------------------*/
3054 z80_assignRegisters (eBBlock ** ebbs, int count)
3059 D (D_ALLOC, ("\n-> z80_assignRegisters: entered.\n"));
3061 setToNull ((void *) &_G.funcrUsed);
3062 setToNull ((void *) &_G.totRegAssigned);
3063 _G.stackExtend = _G.dataExtend = 0;
3067 /* DE is required for the code gen. */
3068 _G.nRegs = GBZ80_MAX_REGS;
3069 regsZ80 = _gbz80_regs;
3073 _G.nRegs = Z80_MAX_REGS;
3074 regsZ80 = _z80_regs;
3077 /* change assignments this will remove some
3078 live ranges reducing some register pressure */
3079 for (i = 0; i < count; i++)
3080 packRegisters (ebbs[i]);
3082 /* liveranges probably changed by register packing
3083 so we compute them again */
3084 recomputeLiveRanges (ebbs, count);
3086 if (options.dump_pack)
3087 dumpEbbsToFileExt (DUMP_PACK, ebbs, count);
3089 /* first determine for each live range the number of
3090 registers & the type of registers required for each */
3093 /* and serially allocate registers */
3094 serialRegAssign (ebbs, count);
3099 /* if stack was extended then tell the user */
3102 /* werror(W_TOOMANY_SPILS,"stack", */
3103 /* _G.stackExtend,currFunc->name,""); */
3109 /* werror(W_TOOMANY_SPILS,"data space", */
3110 /* _G.dataExtend,currFunc->name,""); */
3114 if (options.dump_rassgn) {
3115 dumpEbbsToFileExt (DUMP_RASSGN, ebbs, count);
3116 dumpLiveRanges (DUMP_LRANGE, liveRanges);
3119 /* after that create the register mask
3120 for each of the instruction */
3121 createRegMask (ebbs, count);
3123 /* now get back the chain */
3124 ic = iCodeLabelOptimize (iCodeFromeBBlock (ebbs, count));
3126 ic = joinPushes (ic);
3128 /* redo that offsets for stacked automatic variables */
3129 redoStackOffsets ();
3133 /* free up any stackSpil locations allocated */
3134 applyToSet (_G.stackSpil, deallocStackSpil);
3136 setToNull ((void *) &_G.stackSpil);
3137 setToNull ((void *) &_G.spiltSet);
3138 /* mark all registers as free */