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 the live range preceeds the point of definition
1172 then ideally we must take into account registers that
1173 have been allocated after sym->liveFrom but freed
1174 before ic->seq. This is complicated, so spill this
1175 symbol instead and let fillGaps handle the allocation. */
1176 if (sym->liveFrom < ic->seq)
1182 /* if it has a spillocation & is used less than
1183 all other live ranges then spill this */
1185 if (sym->usl.spillLoc) {
1186 symbol *leastUsed = leastUsedLR (liveRangesWith (spillable,
1187 allLRs, ebbs[i], ic));
1188 if (leastUsed && leastUsed->used > sym->used) {
1193 /* if none of the liveRanges have a spillLocation then better
1194 to spill this one than anything else already assigned to registers */
1195 if (liveRangesWith(spillable,noSpilLoc,ebbs[i],ic)) {
1196 /* if this is local to this block then we might find a block spil */
1197 if (!(sym->liveFrom >= ebbs[i]->fSeq && sym->liveTo <= ebbs[i]->lSeq)) {
1205 /* else we assign registers to it */
1206 _G.regAssigned = bitVectSetBit (_G.regAssigned, sym->key);
1207 _G.totRegAssigned = bitVectSetBit (_G.totRegAssigned, sym->key);
1209 /* Special case: Try to fit into a reg pair if
1211 D (D_ALLOC, ("serialRegAssign: actually allocing regs!\n"));
1212 if ((sym->nRegs == 2) && tryAllocatingRegPair (sym))
1217 for (j = 0; j < sym->nRegs; j++)
1219 sym->regs[j] = getRegGpr (ic, ebbs[i], sym);
1221 /* if the allocation falied which means
1222 this was spilt then break */
1225 D (D_ALLOC, ("Couldnt alloc (spill)\n"))
1230 /* if it shares registers with operands make sure
1231 that they are in the same position */
1232 if (IC_LEFT (ic) && IS_SYMOP (IC_LEFT (ic)) &&
1233 OP_SYMBOL (IC_LEFT (ic))->nRegs && ic->op != '=')
1234 positionRegs (OP_SYMBOL (IC_RESULT (ic)),
1235 OP_SYMBOL (IC_LEFT (ic)));
1236 /* do the same for the right operand */
1237 if (IC_RIGHT (ic) && IS_SYMOP (IC_RIGHT (ic)) &&
1238 OP_SYMBOL (IC_RIGHT (ic))->nRegs)
1239 positionRegs (OP_SYMBOL (IC_RESULT (ic)),
1240 OP_SYMBOL (IC_RIGHT (ic)));
1246 /* Check for and fix any problems with uninitialized operands */
1247 for (i = 0; i < count; i++)
1251 if (ebbs[i]->noPath &&
1252 (ebbs[i]->entryLabel != entryLabel &&
1253 ebbs[i]->entryLabel != returnLabel))
1256 for (ic = ebbs[i]->sch; ic; ic = ic->next)
1263 verifyRegsAssigned (IC_COND (ic), ic);
1267 if (ic->op == JUMPTABLE)
1269 verifyRegsAssigned (IC_JTCOND (ic), ic);
1273 verifyRegsAssigned (IC_RESULT (ic), ic);
1274 verifyRegsAssigned (IC_LEFT (ic), ic);
1275 verifyRegsAssigned (IC_RIGHT (ic), ic);
1281 /*-----------------------------------------------------------------*/
1282 /* fillGaps - Try to fill in the Gaps left by Pass1 */
1283 /*-----------------------------------------------------------------*/
1284 static void fillGaps()
1289 if (getenv("DISABLE_FILL_GAPS")) return;
1291 /* look for livernages that was spilt by the allocator */
1292 for (sym = hTabFirstItem(liveRanges,&key) ; sym ;
1293 sym = hTabNextItem(liveRanges,&key)) {
1298 if (!sym->spillA || !sym->clashes || sym->remat) continue ;
1300 /* find the liveRanges this one clashes with, that are
1301 still assigned to registers & mark the registers as used*/
1302 for ( i = 0 ; i < sym->clashes->size ; i ++) {
1306 if (bitVectBitValue(sym->clashes,i) == 0 || /* those that clash with this */
1307 bitVectBitValue(_G.totRegAssigned,i) == 0) /* and are still assigned to registers */
1310 clr = hTabItemWithKey(liveRanges,i);
1313 /* mark these registers as used */
1314 for (k = 0 ; k < clr->nRegs ; k++ )
1315 useReg(clr->regs[k]);
1318 if (willCauseSpill(sym->nRegs,sym->regType)) {
1319 /* NOPE :( clear all registers & and continue */
1324 /* THERE IS HOPE !!!! */
1325 for (i=0; i < sym->nRegs ; i++ ) {
1326 sym->regs[i] = getRegGprNoSpil ();
1329 /* for all its definitions check if the registers
1330 allocated needs positioning NOTE: we can position
1331 only ONCE if more than One positioning required
1334 for (i = 0 ; i < sym->defs->size ; i++ ) {
1335 if (bitVectBitValue(sym->defs,i)) {
1337 if (!(ic = hTabItemWithKey(iCodehTab,i))) continue ;
1338 if (SKIP_IC(ic)) continue;
1339 assert(isSymbolEqual(sym,OP_SYMBOL(IC_RESULT(ic)))); /* just making sure */
1340 /* if left is assigned to registers */
1341 if (IS_SYMOP(IC_LEFT(ic)) &&
1342 bitVectBitValue(_G.totRegAssigned,OP_SYMBOL(IC_LEFT(ic))->key)) {
1343 pdone += positionRegs(sym,OP_SYMBOL(IC_LEFT(ic)));
1345 if (IS_SYMOP(IC_RIGHT(ic)) &&
1346 bitVectBitValue(_G.totRegAssigned,OP_SYMBOL(IC_RIGHT(ic))->key)) {
1347 pdone += positionRegs(sym,OP_SYMBOL(IC_RIGHT(ic)));
1349 if (pdone > 1) break;
1352 for (i = 0 ; i < sym->uses->size ; i++ ) {
1353 if (bitVectBitValue(sym->uses,i)) {
1355 if (!(ic = hTabItemWithKey(iCodehTab,i))) continue ;
1356 if (SKIP_IC(ic)) continue;
1357 if (!IS_ASSIGN_ICODE(ic)) continue ;
1359 /* if result is assigned to registers */
1360 if (IS_SYMOP(IC_RESULT(ic)) &&
1361 bitVectBitValue(_G.totRegAssigned,OP_SYMBOL(IC_RESULT(ic))->key)) {
1362 pdone += positionRegs(sym,OP_SYMBOL(IC_RESULT(ic)));
1364 if (pdone > 1) break;
1367 /* had to position more than once GIVE UP */
1369 /* UNDO all the changes we made to try this */
1371 for (i=0; i < sym->nRegs ; i++ ) {
1372 sym->regs[i] = NULL;
1375 D(D_FILL_GAPS,("Fill Gap gave up due to positioning for %s in function %s\n",sym->name, currFunc ? currFunc->name : "UNKNOWN"));
1378 D(D_FILL_GAPS,("FILLED GAP for %s in function %s\n",sym->name, currFunc ? currFunc->name : "UNKNOWN"));
1379 _G.totRegAssigned = bitVectSetBit(_G.totRegAssigned,sym->key);
1380 sym->isspilt = sym->spillA = 0 ;
1381 sym->usl.spillLoc->allocreq--;
1386 /*-----------------------------------------------------------------*/
1387 /* rUmaskForOp :- returns register mask for an operand */
1388 /*-----------------------------------------------------------------*/
1390 rUmaskForOp (operand * op)
1396 /* only temporaries are assigned registers */
1400 sym = OP_SYMBOL (op);
1402 /* if spilt or no registers assigned to it
1404 if (sym->isspilt || !sym->nRegs)
1407 rumask = newBitVect (_G.nRegs);
1409 for (j = 0; j < sym->nRegs; j++)
1411 rumask = bitVectSetBit (rumask, sym->regs[j]->rIdx);
1418 z80_rUmaskForOp (operand * op)
1420 return rUmaskForOp (op);
1423 /** Returns bit vector of registers used in iCode.
1426 regsUsedIniCode (iCode * ic)
1428 bitVect *rmask = newBitVect (_G.nRegs);
1430 /* do the special cases first */
1433 rmask = bitVectUnion (rmask,
1434 rUmaskForOp (IC_COND (ic)));
1438 /* for the jumptable */
1439 if (ic->op == JUMPTABLE)
1441 rmask = bitVectUnion (rmask,
1442 rUmaskForOp (IC_JTCOND (ic)));
1447 /* of all other cases */
1449 rmask = bitVectUnion (rmask,
1450 rUmaskForOp (IC_LEFT (ic)));
1454 rmask = bitVectUnion (rmask,
1455 rUmaskForOp (IC_RIGHT (ic)));
1458 rmask = bitVectUnion (rmask,
1459 rUmaskForOp (IC_RESULT (ic)));
1465 /** For each instruction will determine the regsUsed.
1468 createRegMask (eBBlock ** ebbs, int count)
1472 /* for all blocks */
1473 for (i = 0; i < count; i++)
1477 if (ebbs[i]->noPath &&
1478 (ebbs[i]->entryLabel != entryLabel &&
1479 ebbs[i]->entryLabel != returnLabel))
1482 /* for all instructions */
1483 for (ic = ebbs[i]->sch; ic; ic = ic->next)
1488 if (SKIP_IC2 (ic) || !ic->rlive)
1491 /* first mark the registers used in this
1493 ic->rUsed = regsUsedIniCode (ic);
1494 _G.funcrUsed = bitVectUnion (_G.funcrUsed, ic->rUsed);
1496 /* now create the register mask for those
1497 registers that are in use : this is a
1498 super set of ic->rUsed */
1499 ic->rMask = newBitVect (_G.nRegs + 1);
1501 /* for all live Ranges alive at this point */
1502 for (j = 1; j < ic->rlive->size; j++)
1507 /* if not alive then continue */
1508 if (!bitVectBitValue (ic->rlive, j))
1511 /* find the live range we are interested in */
1512 if (!(sym = hTabItemWithKey (liveRanges, j)))
1514 werror (E_INTERNAL_ERROR, __FILE__, __LINE__,
1515 "createRegMask cannot find live range");
1519 /* if no register assigned to it */
1520 if (!sym->nRegs || sym->isspilt)
1523 /* for all the registers allocated to it */
1524 for (k = 0; k < sym->nRegs; k++)
1527 bitVectSetBit (ic->rMask, sym->regs[k]->rIdx);
1533 /** Returns the rematerialized string for a remat var.
1536 rematStr (symbol * sym)
1539 iCode *ic = sym->rematiCode;
1544 /* if plus or minus print the right hand side */
1545 if (ic->op == '+' || ic->op == '-')
1547 sprintf (s, "0x%04x %c ", (int) operandLitValue (IC_RIGHT (ic)),
1550 ic = OP_SYMBOL (IC_LEFT (ic))->rematiCode;
1553 /* we reached the end */
1554 sprintf (s, "%s", OP_SYMBOL (IC_LEFT (ic))->rname);
1561 /*-----------------------------------------------------------------*/
1562 /* regTypeNum - computes the type & number of registers required */
1563 /*-----------------------------------------------------------------*/
1570 /* for each live range do */
1571 for (sym = hTabFirstItem (liveRanges, &k); sym;
1572 sym = hTabNextItem (liveRanges, &k))
1575 /* if used zero times then no registers needed */
1576 if ((sym->liveTo - sym->liveFrom) == 0)
1579 D (D_ALLOC, ("regTypeNum: loop on sym %p\n", sym));
1581 /* if the live range is a temporary */
1585 /* if the type is marked as a conditional */
1586 if (sym->regType == REG_CND)
1589 /* if used in return only then we don't
1591 if (sym->ruonly || sym->accuse)
1593 if (IS_AGGREGATE (sym->type) || sym->isptr)
1594 sym->type = aggrToPtr (sym->type, FALSE);
1598 /* if not then we require registers */
1599 D (D_ALLOC, ("regTypeNum: isagg %u nRegs %u type %p\n", IS_AGGREGATE (sym->type) || sym->isptr, sym->nRegs, sym->type));
1600 sym->nRegs = ((IS_AGGREGATE (sym->type) || sym->isptr) ?
1601 getSize (sym->type = aggrToPtr (sym->type, FALSE)) :
1602 getSize (sym->type));
1603 D (D_ALLOC, ("regTypeNum: setting nRegs of %s (%p) to %u\n", sym->name, sym, sym->nRegs));
1605 D (D_ALLOC, ("regTypeNum: setup to assign regs sym %p\n", sym));
1609 fprintf (stderr, "allocated more than 4 or 0 registers for type ");
1610 printTypeChain (sym->type, stderr);
1611 fprintf (stderr, "\n");
1614 /* determine the type of register required */
1615 /* Always general purpose */
1616 sym->regType = REG_GPR;
1621 /* for the first run we don't provide */
1622 /* registers for true symbols we will */
1623 /* see how things go */
1624 D (D_ALLOC, ("regTypeNum: #2 setting num of %p to 0\n", sym));
1631 /** Mark all registers as free.
1638 D (D_ALLOC, ("freeAllRegs: running.\n"));
1640 for (i = 0; i < _G.nRegs; i++)
1641 regsZ80[i].isFree = 1;
1644 /*-----------------------------------------------------------------*/
1645 /* deallocStackSpil - this will set the stack pointer back */
1646 /*-----------------------------------------------------------------*/
1647 DEFSETFUNC (deallocStackSpil)
1655 /** Register reduction for assignment.
1658 packRegsForAssign (iCode * ic, eBBlock * ebp)
1662 D (D_ALLOC, ("packRegsForAssign: running on ic %p\n", ic));
1664 if (!IS_ITEMP (IC_RIGHT (ic)) ||
1665 OP_SYMBOL (IC_RIGHT (ic))->isind ||
1666 OP_LIVETO (IC_RIGHT (ic)) > ic->seq)
1671 /* find the definition of iTempNN scanning backwards if we find a
1672 a use of the true symbol in before we find the definition then
1674 for (dic = ic->prev; dic; dic = dic->prev)
1676 /* PENDING: Don't pack across function calls. */
1677 if (dic->op == CALL || dic->op == PCALL)
1686 if (IS_SYMOP (IC_RESULT (dic)) &&
1687 IC_RESULT (dic)->key == IC_RIGHT (ic)->key)
1692 if (IS_SYMOP (IC_RIGHT (dic)) &&
1693 (IC_RIGHT (dic)->key == IC_RESULT (ic)->key ||
1694 IC_RIGHT (dic)->key == IC_RIGHT (ic)->key))
1700 if (IS_SYMOP (IC_LEFT (dic)) &&
1701 (IC_LEFT (dic)->key == IC_RESULT (ic)->key ||
1702 IC_LEFT (dic)->key == IC_RIGHT (ic)->key))
1710 return 0; /* did not find */
1712 /* if the result is on stack or iaccess then it must be
1713 the same atleast one of the operands */
1714 if (OP_SYMBOL (IC_RESULT (ic))->onStack ||
1715 OP_SYMBOL (IC_RESULT (ic))->iaccess)
1717 /* the operation has only one symbol
1718 operator then we can pack */
1719 if ((IC_LEFT (dic) && !IS_SYMOP (IC_LEFT (dic))) ||
1720 (IC_RIGHT (dic) && !IS_SYMOP (IC_RIGHT (dic))))
1723 if (!((IC_LEFT (dic) &&
1724 IC_RESULT (ic)->key == IC_LEFT (dic)->key) ||
1726 IC_RESULT (ic)->key == IC_RIGHT (dic)->key)))
1730 /* found the definition */
1731 /* replace the result with the result of */
1732 /* this assignment and remove this assignment */
1733 bitVectUnSetBit(OP_SYMBOL(IC_RESULT(dic))->defs,dic->key);
1734 IC_RESULT (dic) = IC_RESULT (ic);
1736 if (IS_ITEMP (IC_RESULT (dic)) && OP_SYMBOL (IC_RESULT (dic))->liveFrom > dic->seq)
1738 OP_SYMBOL (IC_RESULT (dic))->liveFrom = dic->seq;
1740 /* delete from liverange table also
1741 delete from all the points inbetween and the new
1743 for (sic = dic; sic != ic; sic = sic->next)
1745 bitVectUnSetBit (sic->rlive, IC_RESULT (ic)->key);
1746 if (IS_ITEMP (IC_RESULT (dic)))
1747 bitVectSetBit (sic->rlive, IC_RESULT (dic)->key);
1750 remiCodeFromeBBlock (ebp, ic);
1751 // PENDING: Check vs mcs51
1752 bitVectUnSetBit(OP_SYMBOL(IC_RESULT(ic))->defs,ic->key);
1753 hTabDeleteItem (&iCodehTab, ic->key, ic, DELETE_ITEM, NULL);
1754 OP_DEFS(IC_RESULT (dic))=bitVectSetBit (OP_DEFS (IC_RESULT (dic)), dic->key);
1758 /** Scanning backwards looks for first assig found.
1761 findAssignToSym (operand * op, iCode * ic)
1765 for (dic = ic->prev; dic; dic = dic->prev)
1768 /* if definition by assignment */
1769 if (dic->op == '=' &&
1770 !POINTER_SET (dic) &&
1771 IC_RESULT (dic)->key == op->key)
1772 /* && IS_TRUE_SYMOP(IC_RIGHT(dic)) */
1775 /* we are interested only if defined in far space */
1776 /* or in stack space in case of + & - */
1778 /* if assigned to a non-symbol then return
1780 if (!IS_SYMOP (IC_RIGHT (dic)))
1783 /* if the symbol is in far space then
1785 if (isOperandInFarSpace (IC_RIGHT (dic)))
1788 /* for + & - operations make sure that
1789 if it is on the stack it is the same
1790 as one of the three operands */
1791 if ((ic->op == '+' || ic->op == '-') &&
1792 OP_SYMBOL (IC_RIGHT (dic))->onStack)
1795 if (IC_RESULT (ic)->key != IC_RIGHT (dic)->key &&
1796 IC_LEFT (ic)->key != IC_RIGHT (dic)->key &&
1797 IC_RIGHT (ic)->key != IC_RIGHT (dic)->key)
1805 /* if we find an usage then we cannot delete it */
1806 if (IC_LEFT (dic) && IC_LEFT (dic)->key == op->key)
1809 if (IC_RIGHT (dic) && IC_RIGHT (dic)->key == op->key)
1812 if (POINTER_SET (dic) && IC_RESULT (dic)->key == op->key)
1816 /* now make sure that the right side of dic
1817 is not defined between ic & dic */
1820 iCode *sic = dic->next;
1822 for (; sic != ic; sic = sic->next)
1823 if (IC_RESULT (sic) &&
1824 IC_RESULT (sic)->key == IC_RIGHT (dic)->key)
1833 #if !DISABLE_PACKREGSFORSUPPORT
1836 /*-----------------------------------------------------------------*/
1837 /* packRegsForSupport :- reduce some registers for support calls */
1838 /*-----------------------------------------------------------------*/
1840 packRegsForSupport (iCode * ic, eBBlock * ebp)
1843 /* for the left & right operand :- look to see if the
1844 left was assigned a true symbol in far space in that
1845 case replace them */
1846 D (D_ALLOC, ("packRegsForSupport: running on ic %p\n", ic));
1848 if (IS_ITEMP (IC_LEFT (ic)) &&
1849 OP_SYMBOL (IC_LEFT (ic))->liveTo <= ic->seq)
1851 iCode *dic = findAssignToSym (IC_LEFT (ic), ic);
1857 /* found it we need to remove it from the
1859 for (sic = dic; sic != ic; sic = sic->next)
1860 bitVectUnSetBit (sic->rlive, IC_LEFT (ic)->key);
1862 IC_LEFT (ic)->operand.symOperand =
1863 IC_RIGHT (dic)->operand.symOperand;
1864 IC_LEFT (ic)->key = IC_RIGHT (dic)->operand.symOperand->key;
1865 remiCodeFromeBBlock (ebp, dic);
1866 bitVectUnSetBit(OP_SYMBOL(IC_RESULT(dic))->defs,dic->key);
1867 hTabDeleteItem (&iCodehTab, dic->key, dic, DELETE_ITEM, NULL);
1868 // PENDING: Check vs mcs51
1872 /* do the same for the right operand */
1875 IS_ITEMP (IC_RIGHT (ic)) &&
1876 OP_SYMBOL (IC_RIGHT (ic))->liveTo <= ic->seq)
1878 iCode *dic = findAssignToSym (IC_RIGHT (ic), ic);
1884 /* found it we need to remove it from the block */
1885 for (sic = dic; sic != ic; sic = sic->next)
1886 bitVectUnSetBit (sic->rlive, IC_RIGHT (ic)->key);
1888 IC_RIGHT (ic)->operand.symOperand =
1889 IC_RIGHT (dic)->operand.symOperand;
1890 IC_RIGHT (ic)->key = IC_RIGHT (dic)->operand.symOperand->key;
1892 remiCodeFromeBBlock (ebp, dic);
1893 bitVectUnSetBit(OP_SYMBOL(IC_RESULT(dic))->defs,dic->key);
1894 hTabDeleteItem (&iCodehTab, dic->key, dic, DELETE_ITEM, NULL);
1895 // PENDING: vs mcs51
1903 #define IS_OP_RUONLY(x) (x && IS_SYMOP(x) && OP_SYMBOL(x)->ruonly)
1905 /** Will reduce some registers for single use.
1908 packRegsForOneuse (iCode * ic, operand * op, eBBlock * ebp)
1914 D (D_ALLOC, ("packRegsForOneUse: running on ic %p\n", ic));
1916 /* if returning a literal then do nothing */
1920 /* only upto 2 bytes since we cannot predict
1921 the usage of b, & acc */
1922 if (getSize (operandType (op)) > 2)
1925 if (ic->op != RETURN &&
1929 /* this routine will mark the a symbol as used in one
1930 instruction use only && if the defintion is local
1931 (ie. within the basic block) && has only one definition &&
1932 that definiion is either a return value from a
1933 function or does not contain any variables in
1935 uses = bitVectCopy (OP_USES (op));
1936 bitVectUnSetBit (uses, ic->key); /* take away this iCode */
1937 if (!bitVectIsZero (uses)) /* has other uses */
1940 /* if it has only one defintion */
1941 if (bitVectnBitsOn (OP_DEFS (op)) > 1)
1942 return NULL; /* has more than one definition */
1944 /* get the that definition */
1946 hTabItemWithKey (iCodehTab,
1947 bitVectFirstBit (OP_DEFS (op)))))
1950 /* found the definition now check if it is local */
1951 if (dic->seq < ebp->fSeq ||
1952 dic->seq > ebp->lSeq)
1953 return NULL; /* non-local */
1955 /* now check if it is the return from a function call */
1956 if (dic->op == CALL || dic->op == PCALL)
1958 if (ic->op != SEND && ic->op != RETURN &&
1959 !POINTER_SET(ic) && !POINTER_GET(ic))
1961 OP_SYMBOL (op)->ruonly = 1;
1967 /* otherwise check that the definition does
1968 not contain any symbols in far space */
1969 if (isOperandInFarSpace (IC_LEFT (dic)) ||
1970 isOperandInFarSpace (IC_RIGHT (dic)) ||
1971 IS_OP_RUONLY (IC_LEFT (ic)) ||
1972 IS_OP_RUONLY (IC_RIGHT (ic)))
1977 /* if pointer set then make sure the pointer is one byte */
1978 if (POINTER_SET (dic))
1981 if (POINTER_GET (dic))
1986 /* also make sure the intervenening instructions
1987 don't have any thing in far space */
1988 for (dic = dic->next; dic && dic != ic; dic = dic->next)
1990 /* if there is an intervening function call then no */
1991 if (dic->op == CALL || dic->op == PCALL)
1993 /* if pointer set then make sure the pointer
1995 if (POINTER_SET (dic))
1998 if (POINTER_GET (dic))
2001 /* if address of & the result is remat the okay */
2002 if (dic->op == ADDRESS_OF &&
2003 OP_SYMBOL (IC_RESULT (dic))->remat)
2006 /* if left or right or result is in far space */
2007 if (isOperandInFarSpace (IC_LEFT (dic)) ||
2008 isOperandInFarSpace (IC_RIGHT (dic)) ||
2009 isOperandInFarSpace (IC_RESULT (dic)) ||
2010 IS_OP_RUONLY (IC_LEFT (dic)) ||
2011 IS_OP_RUONLY (IC_RIGHT (dic)) ||
2012 IS_OP_RUONLY (IC_RESULT (dic)))
2018 OP_SYMBOL (op)->ruonly = 1;
2022 /*-----------------------------------------------------------------*/
2023 /* isBitwiseOptimizable - requirements of JEAN LOUIS VERN */
2024 /*-----------------------------------------------------------------*/
2026 isBitwiseOptimizable (iCode * ic)
2028 sym_link *rtype = getSpec (operandType (IC_RIGHT (ic)));
2030 /* bitwise operations are considered optimizable
2031 under the following conditions (Jean-Louis VERN)
2043 if (IS_LITERAL (rtype))
2049 Certian assignments involving pointers can be temporarly stored
2060 #if !DISABLE_PACKREGSFORACCUSE
2063 /** Pack registers for acc use.
2064 When the result of this operation is small and short lived it may
2065 be able to be stored in the accumelator.
2068 packRegsForAccUse (iCode * ic)
2072 /* if this is an aggregate, e.g. a one byte char array */
2073 if (IS_AGGREGATE(operandType(IC_RESULT(ic)))) {
2077 /* if + or - then it has to be one byte result */
2078 if ((ic->op == '+' || ic->op == '-')
2079 && getSize (operandType (IC_RESULT (ic))) > 1)
2082 /* if shift operation make sure right side is not a literal */
2083 if (ic->op == RIGHT_OP &&
2084 (isOperandLiteral (IC_RIGHT (ic)) ||
2085 getSize (operandType (IC_RESULT (ic))) > 1))
2088 if (ic->op == LEFT_OP &&
2089 (isOperandLiteral (IC_RIGHT (ic)) ||
2090 getSize (operandType (IC_RESULT (ic))) > 1))
2093 /* has only one definition */
2094 if (bitVectnBitsOn (OP_DEFS (IC_RESULT (ic))) > 1)
2097 /* has only one use */
2098 if (bitVectnBitsOn (OP_USES (IC_RESULT (ic))) > 1)
2101 /* and the usage immediately follows this iCode */
2102 if (!(uic = hTabItemWithKey (iCodehTab,
2103 bitVectFirstBit (OP_USES (IC_RESULT (ic))))))
2106 if (ic->next != uic)
2109 /* if it is a conditional branch then we definitely can */
2113 if (uic->op == JUMPTABLE)
2117 /* if the usage is not is an assignment or an
2118 arithmetic / bitwise / shift operation then not */
2119 if (POINTER_SET (uic) &&
2120 getSize (aggrToPtr (operandType (IC_RESULT (uic)), FALSE)) > 1)
2124 if (uic->op != '=' &&
2125 !IS_ARITHMETIC_OP (uic) &&
2126 !IS_BITWISE_OP (uic) &&
2127 uic->op != LEFT_OP &&
2128 uic->op != RIGHT_OP)
2131 /* if used in ^ operation then make sure right is not a
2133 if (uic->op == '^' && isOperandLiteral (IC_RIGHT (uic)))
2136 /* if shift operation make sure right side is not a literal */
2137 if (uic->op == RIGHT_OP &&
2138 (isOperandLiteral (IC_RIGHT (uic)) ||
2139 getSize (operandType (IC_RESULT (uic))) > 1))
2142 if (uic->op == LEFT_OP &&
2143 (isOperandLiteral (IC_RIGHT (uic)) ||
2144 getSize (operandType (IC_RESULT (uic))) > 1))
2148 /* make sure that the result of this icode is not on the
2149 stack, since acc is used to compute stack offset */
2150 if (IS_TRUE_SYMOP (IC_RESULT (uic)) &&
2151 OP_SYMBOL (IC_RESULT (uic))->onStack)
2156 /* if either one of them in far space then we cannot */
2157 if ((IS_TRUE_SYMOP (IC_LEFT (uic)) &&
2158 isOperandInFarSpace (IC_LEFT (uic))) ||
2159 (IS_TRUE_SYMOP (IC_RIGHT (uic)) &&
2160 isOperandInFarSpace (IC_RIGHT (uic))))
2164 /* if the usage has only one operand then we can */
2165 if (IC_LEFT (uic) == NULL ||
2166 IC_RIGHT (uic) == NULL)
2169 /* make sure this is on the left side if not
2170 a '+' since '+' is commutative */
2171 if (ic->op != '+' &&
2172 IC_LEFT (uic)->key != IC_RESULT (ic)->key)
2175 // See mcs51 ralloc for reasoning
2177 /* if one of them is a literal then we can */
2178 if ((IC_LEFT (uic) && IS_OP_LITERAL (IC_LEFT (uic))) ||
2179 (IC_RIGHT (uic) && IS_OP_LITERAL (IC_RIGHT (uic))))
2186 /** This is confusing :) Guess for now */
2187 if (IC_LEFT (uic)->key == IC_RESULT (ic)->key &&
2188 (IS_ITEMP (IC_RIGHT (uic)) ||
2189 (IS_TRUE_SYMOP (IC_RIGHT (uic)))))
2192 if (IC_RIGHT (uic)->key == IC_RESULT (ic)->key &&
2193 (IS_ITEMP (IC_LEFT (uic)) ||
2194 (IS_TRUE_SYMOP (IC_LEFT (uic)))))
2198 OP_SYMBOL (IC_RESULT (ic))->accuse = ACCUSE_A;
2203 packRegsForHLUse (iCode * ic)
2207 /* PENDING: Could do IFX */
2213 /* has only one definition */
2214 if (bitVectnBitsOn (OP_DEFS (IC_RESULT (ic))) > 1)
2216 D (D_HLUSE, (" + Dropping as has more than one def\n"));
2220 /* has only one use */
2221 if (bitVectnBitsOn (OP_USES (IC_RESULT (ic))) > 1)
2223 D (D_HLUSE, (" + Dropping as has more than one use\n"));
2227 /* and the usage immediately follows this iCode */
2228 if (!(uic = hTabItemWithKey (iCodehTab,
2229 bitVectFirstBit (OP_USES (IC_RESULT (ic))))))
2231 D (D_HLUSE, (" + Dropping as usage isn't in this block\n"));
2235 if (ic->next != uic)
2237 D (D_HLUSE, (" + Dropping as usage doesn't follow this\n"));
2246 if (getSize (operandType (IC_RESULT (ic))) != 2 ||
2247 (IC_LEFT(uic) && getSize (operandType (IC_LEFT (uic))) != 2) ||
2248 (IC_RIGHT(uic) && getSize (operandType (IC_RIGHT (uic))) != 2))
2250 D (D_HLUSE, (" + Dropping as the result size is not 2\n"));
2256 if (ic->op == CAST && uic->op == IPUSH)
2258 if (ic->op == ADDRESS_OF && uic->op == IPUSH)
2260 if (ic->op == ADDRESS_OF && POINTER_GET (uic) && IS_ITEMP( IC_RESULT (uic)))
2262 if (ic->op == CALL && ic->parmBytes == 0 && (uic->op == '-' || uic->op == '+'))
2267 /* Case of assign a constant to offset in a static array. */
2268 if (ic->op == '+' && IS_VALOP (IC_RIGHT (ic)))
2270 if (uic->op == '=' && POINTER_SET (uic))
2274 else if (uic->op == IPUSH && getSize (operandType (IC_LEFT (uic))) == 2)
2281 D (D_HLUSE, (" + Dropping as it's a bad op\n"));
2284 OP_SYMBOL (IC_RESULT (ic))->accuse = ACCUSE_SCRATCH;
2288 packRegsForHLUse3 (iCode * lic, operand * op, eBBlock * ebp)
2293 bool isFirst = TRUE;
2295 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));
2299 if ( OP_SYMBOL(op)->accuse)
2304 if (OP_SYMBOL(op)->remat)
2309 /* Only defined once */
2310 if (bitVectnBitsOn (OP_DEFS (op)) > 1)
2313 if (getSize (operandType (op)) > 2)
2316 /* And this is the definition */
2317 if (bitVectFirstBit (OP_DEFS (op)) != lic->key)
2320 /* first check if any overlapping liverange has already been
2322 if (OP_SYMBOL(op)->clashes)
2324 for (i = 0 ; i < OP_SYMBOL(op)->clashes->size ; i++ )
2326 if (bitVectBitValue(OP_SYMBOL(op)->clashes,i))
2328 sym = hTabItemWithKey(liveRanges,i);
2329 if (sym->accuse == ACCUSE_SCRATCH)
2337 /* Nothing else that clashes with this is using the scratch
2338 register. Scan through all of the intermediate instructions and
2339 see if any of them could nuke HL.
2341 dic = ic = hTabFirstItemWK(iCodeSeqhTab,OP_SYMBOL(op)->liveFrom);
2343 for (; ic && ic->seq <= OP_SYMBOL(op)->liveTo;
2344 ic = hTabNextItem(iCodeSeqhTab, &key))
2348 D (D_PACK_HLUSE3, ("(On %p: op: %u next: %p)\n", ic, ic->op, ic->next));
2353 if (ic->op == ADDRESS_OF)
2355 if (POINTER_GET (ic))
2357 if (ic->op == '=' && !POINTER_SET(ic))
2361 if (IC_RESULT(ic) && IS_SYMOP(IC_RESULT(ic))
2362 && isOperandInDirSpace (IC_RESULT (ic)))
2365 if (IC_LEFT(ic) && IS_SYMOP(IC_LEFT(ic))
2366 && isOperandInDirSpace (IC_LEFT (ic)))
2369 if (IC_RIGHT(ic) && IS_SYMOP(IC_RIGHT(ic))
2370 && isOperandInDirSpace (IC_RIGHT (ic)))
2373 /* Handle the non left/right/result ones first */
2376 if (ic->op == JUMPTABLE)
2385 if (ic->op == IPUSH && isOperandEqual (op, IC_LEFT (ic)))
2388 if (ic->op == SEND && isOperandEqual (op, IC_LEFT (ic)))
2391 if (ic->op == CALL && isOperandEqual (op, IC_RESULT (ic)))
2394 if (ic->op == LEFT_OP && isOperandLiteral (IC_RIGHT (ic)))
2397 if ((ic->op == '=' && !POINTER_SET(ic)) ||
2398 ic->op == UNARYMINUS ||
2407 if (ic->op == '*' && isOperandEqual (op, IC_LEFT (ic)))
2410 if (POINTER_SET (ic) && isOperandEqual (op, IC_RESULT (ic)))
2413 if (POINTER_GET (ic) && isOperandEqual (op, IC_LEFT (ic)))
2416 if (IS_VALOP (IC_RIGHT (ic)) &&
2423 /* By default give up */
2427 D (D_PACK_HLUSE3, ("Succeeded!\n"))
2429 OP_SYMBOL (op)->accuse = ACCUSE_SCRATCH;
2434 packRegsForIYUse (iCode * lic, operand * op, eBBlock * ebp)
2441 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));
2445 if ( OP_SYMBOL(op)->accuse)
2450 if (OP_SYMBOL(op)->remat)
2455 /* Only defined once */
2456 if (bitVectnBitsOn (OP_DEFS (op)) > 1)
2459 /* And this is the definition */
2460 if (bitVectFirstBit (OP_DEFS (op)) != lic->key)
2463 /* first check if any overlapping liverange has already been
2465 if (OP_SYMBOL(op)->clashes)
2467 for (i = 0 ; i < OP_SYMBOL(op)->clashes->size ; i++ )
2469 if (bitVectBitValue(OP_SYMBOL(op)->clashes,i))
2471 sym = hTabItemWithKey(liveRanges,i);
2472 if (sym->accuse == ACCUSE_IY)
2480 /* Only a few instructions can load into IY */
2486 if (getSize (operandType (op)) != 2)
2488 D (D_ACCUSE2, (" + Dropping as operation has size is too big\n"));
2492 /* Nothing else that clashes with this is using the scratch
2493 register. Scan through all of the intermediate instructions and
2494 see if any of them could nuke HL.
2496 dic = ic = hTabFirstItemWK(iCodeSeqhTab,OP_SYMBOL(op)->liveFrom);
2499 for (; ic && ic->seq <= OP_SYMBOL(op)->liveTo;
2500 ic = hTabNextItem(iCodeSeqhTab,&key))
2505 if (ic->op == PCALL ||
2514 /* Be pessamistic. */
2518 D (D_PACK_IY, (" op: %u uses %u result: %d left: %d right: %d\n", ic->op, bitVectBitValue(uses, ic->key),
2519 IC_RESULT(ic) && IS_SYMOP(IC_RESULT(ic)) ? isOperandInDirSpace(IC_RESULT(ic)) : -1,
2520 IC_LEFT(ic) && IS_SYMOP(IC_LEFT(ic)) ? isOperandInDirSpace(IC_LEFT(ic)) : -1,
2521 IC_RIGHT(ic) && IS_SYMOP(IC_RIGHT(ic)) ? isOperandInDirSpace(IC_RIGHT(ic)) : -1
2524 if (IC_RESULT(ic) && IS_SYMOP(IC_RESULT(ic)) &&
2525 isOperandInDirSpace(IC_RESULT(ic)))
2528 if (IC_RIGHT(ic) && IS_SYMOP(IC_RIGHT(ic)) &&
2529 isOperandInDirSpace(IC_RIGHT(ic)))
2532 if (IC_LEFT(ic) && IS_SYMOP(IC_LEFT(ic)) &&
2533 isOperandInDirSpace(IC_LEFT(ic)))
2536 /* Only certain rules will work against IY. Check if this iCode uses
2538 if (bitVectBitValue(uses, ic->key) != 0)
2540 if (ic->op == '=' &&
2541 isOperandEqual(IC_RESULT(ic), op))
2544 if (ic->op == GET_VALUE_AT_ADDRESS &&
2545 isOperandEqual(IC_LEFT(ic), op))
2548 if (isOperandEqual(IC_RESULT(ic), IC_LEFT(ic)) == FALSE)
2551 if (IC_RIGHT (ic) && IS_VALOP (IC_RIGHT (ic)))
2553 if (ic->op == '+' ||
2556 /* Only works if the constant is small */
2557 if (operandLitValue (IC_RIGHT (ic)) < 4)
2566 /* This iCode doesn't use the sym. See if this iCode preserves IY.
2571 /* By default give up */
2575 D (D_PACK_IY, ("Succeeded IY!\n"));
2577 OP_SYMBOL (op)->accuse = ACCUSE_IY;
2581 /** Returns TRUE if this operation can use acc and if it preserves the value.
2584 opPreservesA (iCode * uic)
2588 /* If we've gotten this far then the thing to compare must be
2589 small enough and must be in A.
2594 if (uic->op == JUMPTABLE)
2596 D (D_ACCUSE2, (" + Dropping as operation is a Jumptable\n"));
2600 /* A pointer assign preserves A if A is the left value. */
2601 if (uic->op == '=' && POINTER_SET (uic))
2606 /* if the usage has only one operand then we can */
2607 /* PENDING: check */
2608 if (IC_LEFT (uic) == NULL ||
2609 IC_RIGHT (uic) == NULL)
2611 D (D_ACCUSE2, (" + Dropping as operation has only one operand\n"));
2615 /* PENDING: check this rule */
2616 if (getSize (operandType (IC_RESULT (uic))) > 1)
2618 D (D_ACCUSE2, (" + Dropping as operation has size is too big\n"));
2623 /* Disabled all of the old rules as they weren't verified and have
2624 caused at least one problem.
2629 /** Returns true if this operand preserves the value of A.
2632 opIgnoresA (iCode * ic, iCode * uic)
2634 /* A increment of an iTemp by a constant is OK. */
2635 if ( uic->op == '+' &&
2636 IS_ITEMP (IC_LEFT (uic)) &&
2637 IS_ITEMP (IC_RESULT (uic)) &&
2638 IS_OP_LITERAL (IC_RIGHT (uic)))
2640 unsigned int icount = (unsigned int) floatFromVal (IC_RIGHT (uic)->operand.valOperand);
2642 /* Being an ITEMP means that we're already a symbol. */
2644 IC_RESULT (uic)->operand.symOperand->key == IC_LEFT (uic)->operand.symOperand->key
2650 else if (uic->op == '=' && !POINTER_SET (uic))
2652 /* If they are equal and get optimised out then things are OK. */
2653 if (isOperandEqual (IC_RESULT (uic), IC_RIGHT (uic)))
2655 /* Straight assign is OK. */
2664 /* Some optimisation cases:
2676 ; genAssign (pointer)
2680 want to optimise down to:
2686 So genPointer get is OK
2687 genPlus where the right is constant, left is iTemp, and result is same as left
2688 genAssign (pointer) is OK
2699 ; genAssign (pointer)
2700 ; AOP_STK for _strcpy_to_1_1
2705 want to optimise down to:
2711 So genIfx where IC_COND has size of 1 and is a constant.
2714 /** Pack registers for acc use.
2715 When the result of this operation is small and short lived it may
2716 be able to be stored in the accumulator.
2718 Note that the 'A preserving' list is currently emperical :)
2721 packRegsForAccUse2 (iCode * ic)
2725 D (D_ACCUSE2, ("packRegsForAccUse2: running on ic %p line %u\n", ic, ic->lineno));
2729 /* Filter out all but those 'good' commands */
2731 !POINTER_GET (ic) &&
2734 !IS_BITWISE_OP (ic) &&
2740 ic->op != GETHBIT &&
2743 D (D_ACCUSE2, (" + Dropping as not a 'good' source command\n"));
2747 /* if + or - then it has to be one byte result.
2750 if ((ic->op == '+' || ic->op == '-')
2751 && getSize (operandType (IC_RESULT (ic))) > 1)
2753 D (D_ACCUSE2, (" + Dropping as it's a big + or -\n"));
2757 /* has only one definition */
2758 if (bitVectnBitsOn (OP_DEFS (IC_RESULT (ic))) > 1)
2760 D (D_ACCUSE2, (" + Dropping as it has more than one definition\n"));
2764 /* Right. We may be able to propagate it through if:
2765 For each in the chain of uses the intermediate is OK.
2767 /* Get next with 'uses result' bit on
2768 If this->next == next
2769 Validate use of next
2770 If OK, increase count
2772 /* and the usage immediately follows this iCode */
2773 if (!(uic = hTabItemWithKey (iCodehTab,
2774 bitVectFirstBit (OP_USES (IC_RESULT (ic))))))
2776 D (D_ACCUSE2, (" + Dropping as usage does not follow first\n"));
2781 /* Create a copy of the OP_USES bit vect */
2782 bitVect *uses = bitVectCopy (OP_USES (IC_RESULT (ic)));
2784 iCode *scan = ic, *next;
2788 setBit = bitVectFirstBit (uses);
2789 next = hTabItemWithKey (iCodehTab, setBit);
2790 if (scan->next == next)
2792 D (D_ACCUSE2_VERBOSE, (" ! Is next in line\n"));
2794 bitVectUnSetBit (uses, setBit);
2795 /* Still contigous. */
2796 if (!opPreservesA (next))
2798 D (D_ACCUSE2, (" + Dropping as operation doesn't preserve A\n"));
2801 D (D_ACCUSE2_VERBOSE, (" ! Preserves A, so continue scanning\n"));
2804 else if (scan->next == NULL && bitVectnBitsOn (uses) == 1 && next != NULL)
2806 if (next->prev == NULL)
2808 if (!opPreservesA (next))
2810 D (D_ACCUSE2, (" + Dropping as operation doesn't preserve A #2\n"));
2813 bitVectUnSetBit (uses, setBit);
2818 D (D_ACCUSE2, (" + Dropping as last in list and next doesn't start a block\n"));
2822 else if (scan->next == NULL)
2824 D (D_ACCUSE2, (" + Dropping as hit the end of the list\n"));
2825 D (D_ACCUSE2, (" + Next in htab: %p\n", next));
2830 if (opIgnoresA (ic, scan->next))
2834 D (D_ACCUSE2_VERBOSE, (" ! Op ignores A, so continue scanning\n"));
2838 D (D_ACCUSE2, (" + Dropping as parts are not consecuitive and intermediate might use A\n"));
2843 while (!bitVectIsZero (uses));
2845 OP_SYMBOL (IC_RESULT (ic))->accuse = ACCUSE_A;
2850 /** Does some transformations to reduce register pressure.
2853 packRegisters (eBBlock * ebp)
2858 D (D_ALLOC, ("packRegisters: entered.\n"));
2860 while (1 && !DISABLE_PACK_ASSIGN)
2863 /* look for assignments of the form */
2864 /* iTempNN = TRueSym (someoperation) SomeOperand */
2866 /* TrueSym := iTempNN:1 */
2867 for (ic = ebp->sch; ic; ic = ic->next)
2869 /* find assignment of the form TrueSym := iTempNN:1 */
2870 if (ic->op == '=' && !POINTER_SET (ic))
2871 change += packRegsForAssign (ic, ebp);
2877 for (ic = ebp->sch; ic; ic = ic->next)
2879 /* Safe: address of a true sym is always constant. */
2880 /* if this is an itemp & result of a address of a true sym
2881 then mark this as rematerialisable */
2882 D (D_ALLOC, ("packRegisters: looping on ic %p\n", ic));
2884 if (ic->op == ADDRESS_OF &&
2885 IS_ITEMP (IC_RESULT (ic)) &&
2886 IS_TRUE_SYMOP (IC_LEFT (ic)) &&
2887 bitVectnBitsOn (OP_DEFS (IC_RESULT (ic))) == 1 &&
2888 !OP_SYMBOL (IC_LEFT (ic))->onStack)
2891 OP_SYMBOL (IC_RESULT (ic))->remat = 1;
2892 OP_SYMBOL (IC_RESULT (ic))->rematiCode = ic;
2893 OP_SYMBOL (IC_RESULT (ic))->usl.spillLoc = NULL;
2896 /* Safe: just propagates the remat flag */
2897 /* if straight assignment then carry remat flag if this is the
2899 if (ic->op == '=' &&
2900 !POINTER_SET (ic) &&
2901 IS_SYMOP (IC_RIGHT (ic)) &&
2902 OP_SYMBOL (IC_RIGHT (ic))->remat &&
2903 bitVectnBitsOn (OP_SYMBOL (IC_RESULT (ic))->defs) <= 1)
2906 OP_SYMBOL (IC_RESULT (ic))->remat =
2907 OP_SYMBOL (IC_RIGHT (ic))->remat;
2908 OP_SYMBOL (IC_RESULT (ic))->rematiCode =
2909 OP_SYMBOL (IC_RIGHT (ic))->rematiCode;
2912 /* if the condition of an if instruction is defined in the
2913 previous instruction then mark the itemp as a conditional */
2914 if ((IS_CONDITIONAL (ic) ||
2915 ((ic->op == BITWISEAND ||
2918 isBitwiseOptimizable (ic))) &&
2919 ic->next && ic->next->op == IFX &&
2920 bitVectnBitsOn (OP_USES(IC_RESULT(ic)))==1 &&
2921 isOperandEqual (IC_RESULT (ic), IC_COND (ic->next)) &&
2922 OP_SYMBOL (IC_RESULT (ic))->liveTo <= ic->next->seq)
2925 OP_SYMBOL (IC_RESULT (ic))->regType = REG_CND;
2930 /* reduce for support function calls */
2931 if (ic->supportRtn || ic->op == '+' || ic->op == '-')
2932 packRegsForSupport (ic, ebp);
2935 /* some cases the redundant moves can
2936 can be eliminated for return statements */
2937 if (ic->op == RETURN || ic->op == SEND)
2939 packRegsForOneuse (ic, IC_LEFT (ic), ebp);
2942 /* if pointer set & left has a size more than
2943 one and right is not in far space */
2944 if (!DISABLE_PACK_ONE_USE &&
2946 /* MLH: no such thing.
2947 !isOperandInFarSpace(IC_RIGHT(ic)) && */
2948 !OP_SYMBOL (IC_RESULT (ic))->remat &&
2949 !IS_OP_RUONLY (IC_RIGHT (ic)) &&
2950 getSize (aggrToPtr (operandType (IC_RESULT (ic)), FALSE)) > 1)
2953 packRegsForOneuse (ic, IC_RESULT (ic), ebp);
2956 /* if pointer get */
2957 if (!DISABLE_PACK_ONE_USE &&
2959 IS_SYMOP (IC_LEFT (ic)) &&
2960 /* MLH: dont have far space
2961 !isOperandInFarSpace(IC_RESULT(ic))&& */
2962 !OP_SYMBOL (IC_LEFT (ic))->remat &&
2963 !IS_OP_RUONLY (IC_RESULT (ic)) &&
2964 getSize (aggrToPtr (operandType (IC_LEFT (ic)), FALSE)) > 1)
2967 packRegsForOneuse (ic, IC_LEFT (ic), ebp);
2970 /* pack registers for accumulator use, when the result of an
2971 arithmetic or bit wise operation has only one use, that use is
2972 immediately following the defintion and the using iCode has
2973 only one operand or has two operands but one is literal & the
2974 result of that operation is not on stack then we can leave the
2975 result of this operation in acc:b combination */
2977 if (!DISABLE_PACK_HL && IS_ITEMP (IC_RESULT (ic)))
2983 packRegsForHLUse (ic);
2987 packRegsForHLUse3 (ic, IC_RESULT (ic), ebp);
2991 if (!DISABLE_PACK_IY && IS_ITEMP (IC_RESULT (ic)) && IS_Z80)
2993 packRegsForIYUse (ic, IC_RESULT (ic), ebp);
2996 if (!DISABLE_PACK_ACC && IS_ITEMP (IC_RESULT (ic)) &&
2997 getSize (operandType (IC_RESULT (ic))) == 1)
2999 packRegsForAccUse2 (ic);
3004 /** Joins together two byte constant pushes into one word push.
3007 joinPushes (iCode *lic)
3011 for (ic = lic; ic; ic = ic->next)
3018 /* Anything past this? */
3023 /* This and the next pushes? */
3024 if (ic->op != IPUSH || uic->op != IPUSH)
3028 /* Both literals? */
3029 if ( !IS_OP_LITERAL (IC_LEFT (ic)) || !IS_OP_LITERAL (IC_LEFT (uic)))
3033 /* Both characters? */
3034 if ( getSize (operandType (IC_LEFT (ic))) != 1 || getSize (operandType (IC_LEFT (uic))) != 1)
3038 /* Pull out the values, make a new type, and create the new iCode for it.
3040 first = (int)operandLitValue ( IC_LEFT (ic));
3041 second = (int)operandLitValue ( IC_LEFT (uic));
3043 sprintf (buffer, "%uu", ((first << 8) | (second & 0xFF)) & 0xFFFFU);
3044 val = constVal (buffer);
3045 SPEC_NOUN (val->type) = V_INT;
3046 IC_LEFT (ic) = operandFromOperand (IC_LEFT (ic));
3047 IC_LEFT (ic)->operand.valOperand = val;
3049 /* Now remove the second one from the list. */
3050 ic->next = uic->next;
3053 /* Patch up the reverse link */
3054 uic->next->prev = ic;
3061 /*-----------------------------------------------------------------*/
3062 /* assignRegisters - assigns registers to each live range as need */
3063 /*-----------------------------------------------------------------*/
3065 z80_assignRegisters (eBBlock ** ebbs, int count)
3070 D (D_ALLOC, ("\n-> z80_assignRegisters: entered.\n"));
3072 setToNull ((void *) &_G.funcrUsed);
3073 setToNull ((void *) &_G.totRegAssigned);
3074 _G.stackExtend = _G.dataExtend = 0;
3078 /* DE is required for the code gen. */
3079 _G.nRegs = GBZ80_MAX_REGS;
3080 regsZ80 = _gbz80_regs;
3084 _G.nRegs = Z80_MAX_REGS;
3085 regsZ80 = _z80_regs;
3088 /* change assignments this will remove some
3089 live ranges reducing some register pressure */
3090 for (i = 0; i < count; i++)
3091 packRegisters (ebbs[i]);
3093 /* liveranges probably changed by register packing
3094 so we compute them again */
3095 recomputeLiveRanges (ebbs, count);
3097 if (options.dump_pack)
3098 dumpEbbsToFileExt (DUMP_PACK, ebbs, count);
3100 /* first determine for each live range the number of
3101 registers & the type of registers required for each */
3104 /* and serially allocate registers */
3105 serialRegAssign (ebbs, count);
3110 /* if stack was extended then tell the user */
3113 /* werror(W_TOOMANY_SPILS,"stack", */
3114 /* _G.stackExtend,currFunc->name,""); */
3120 /* werror(W_TOOMANY_SPILS,"data space", */
3121 /* _G.dataExtend,currFunc->name,""); */
3125 if (options.dump_rassgn) {
3126 dumpEbbsToFileExt (DUMP_RASSGN, ebbs, count);
3127 dumpLiveRanges (DUMP_LRANGE, liveRanges);
3130 /* after that create the register mask
3131 for each of the instruction */
3132 createRegMask (ebbs, count);
3134 /* now get back the chain */
3135 ic = iCodeLabelOptimize (iCodeFromeBBlock (ebbs, count));
3137 ic = joinPushes (ic);
3139 /* redo that offsets for stacked automatic variables */
3140 redoStackOffsets ();
3144 /* free up any stackSpil locations allocated */
3145 applyToSet (_G.stackSpil, deallocStackSpil);
3147 setToNull ((void *) &_G.stackSpil);
3148 setToNull ((void *) &_G.spiltSet);
3149 /* mark all registers as free */