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 %s\n", regsZ80[i].name));
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->liveFrom == ic->seq && /* does not start before here */
890 result->regType == sym->regType && /* same register types */
891 result->nRegs && /* which needs registers */
892 !result->isspilt && /* and does not already have them */
894 !bitVectBitValue (_G.regAssigned, result->key) &&
895 /* the number of free regs + number of regs in this LR
896 can accomodate the what result Needs */
897 ((nfreeRegsType (result->regType) +
898 sym->nRegs) >= result->nRegs)
901 for (i = 0; i < result->nRegs; i++)
904 result->regs[i] = sym->regs[i];
906 result->regs[i] = getRegGpr (ic, ebp, result);
908 /* if the allocation falied which means
909 this was spilt then break */
910 if (!result->regs[i])
918 _G.regAssigned = bitVectSetBit (_G.regAssigned, result->key);
919 _G.totRegAssigned = bitVectSetBit (_G.totRegAssigned, result->key);
922 /* free the remaining */
923 for (; i < sym->nRegs; i++)
927 if (!symHasReg (psym, sym->regs[i]))
928 freeReg (sym->regs[i]);
931 freeReg (sym->regs[i]);
932 // sym->regs[i] = NULL;
939 /** Reassign this to registers.
942 reassignLR (operand * op)
944 symbol *sym = OP_SYMBOL (op);
947 D (D_ALLOC, ("reassingLR: on sym %p\n", sym));
949 /* not spilt any more */
950 sym->isspilt = sym->spillA = sym->blockSpil = sym->remainSpil = 0;
951 bitVectUnSetBit (_G.spiltSet, sym->key);
953 _G.regAssigned = bitVectSetBit (_G.regAssigned, sym->key);
954 _G.totRegAssigned = bitVectSetBit (_G.totRegAssigned, sym->key);
958 for (i = 0; i < sym->nRegs; i++)
959 sym->regs[i]->isFree = 0;
962 /** Determines if allocating will cause a spill.
965 willCauseSpill (int nr, int rt)
967 /* first check if there are any avlb registers
968 of te type required */
969 if (nFreeRegs (0) >= nr)
972 /* it will cause a spil */
976 /** The allocator can allocate same registers to result and operand,
977 if this happens make sure they are in the same position as the operand
978 otherwise chaos results.
981 positionRegs (symbol * result, symbol * opsym)
983 int count = min (result->nRegs, opsym->nRegs);
984 int i, j = 0, shared = 0;
987 D (D_ALLOC, ("positionRegs: on result %p opsum %p line %u\n", result, opsym, lineno));
989 /* if the result has been spilt then cannot share */
994 /* first make sure that they actually share */
995 for (i = 0; i < count; i++)
997 for (j = 0; j < count; j++)
999 if (result->regs[i] == opsym->regs[j] && i != j)
1009 regs *tmp = result->regs[i];
1010 result->regs[i] = result->regs[j];
1011 result->regs[j] = tmp;
1018 /** Try to allocate a pair of registers to the symbol.
1021 tryAllocatingRegPair (symbol * sym)
1024 wassert (sym->nRegs == 2);
1025 for (i = 0; i < _G.nRegs; i += 2)
1027 if ((regsZ80[i].isFree) && (regsZ80[i + 1].isFree))
1029 regsZ80[i].isFree = 0;
1030 sym->regs[0] = ®sZ80[i];
1031 regsZ80[i + 1].isFree = 0;
1032 sym->regs[1] = ®sZ80[i + 1];
1033 sym->regType = REG_PAIR;
1037 currFunc->regsUsed =
1038 bitVectSetBit (currFunc->regsUsed, i);
1039 currFunc->regsUsed =
1040 bitVectSetBit (currFunc->regsUsed, i + 1);
1042 D (D_ALLOC, ("tryAllocatingRegPair: succeded for sym %p\n", sym));
1046 D (D_ALLOC, ("tryAllocatingRegPair: failed on sym %p\n", sym));
1050 /*------------------------------------------------------------------*/
1051 /* verifyRegsAssigned - make sure an iTemp is properly initialized; */
1052 /* it should either have registers or have beed spilled. Otherwise, */
1053 /* there was an uninitialized variable, so just spill this to get */
1054 /* the operand in a valid state. */
1055 /*------------------------------------------------------------------*/
1057 verifyRegsAssigned (operand *op, iCode * ic)
1062 if (!IS_ITEMP (op)) return;
1064 sym = OP_SYMBOL (op);
1065 if (sym->isspilt) return;
1066 if (!sym->nRegs) return;
1067 if (sym->regs[0]) return;
1069 werrorfl (ic->filename, ic->lineno, W_LOCAL_NOINIT,
1070 sym->prereqv ? sym->prereqv->name : sym->name);
1075 /** Serially allocate registers to the variables.
1076 This is the main register allocation function. It is called after
1080 serialRegAssign (eBBlock ** ebbs, int count)
1084 /* for all blocks */
1085 for (i = 0; i < count; i++)
1090 if (ebbs[i]->noPath &&
1091 (ebbs[i]->entryLabel != entryLabel &&
1092 ebbs[i]->entryLabel != returnLabel))
1095 /* of all instructions do */
1096 for (ic = ebbs[i]->sch; ic; ic = ic->next)
1099 /* if this is an ipop that means some live
1100 range will have to be assigned again */
1104 reassignLR (IC_LEFT (ic));
1107 /* if result is present && is a true symbol */
1108 if (IC_RESULT (ic) && ic->op != IFX &&
1109 IS_TRUE_SYMOP (IC_RESULT (ic)))
1110 OP_SYMBOL (IC_RESULT (ic))->allocreq++;
1112 /* take away registers from live
1113 ranges that end at this instruction */
1114 deassignLRs (ic, ebbs[i]);
1116 /* some don't need registers */
1117 /* MLH: removed RESULT and POINTER_SET condition */
1118 if (SKIP_IC2 (ic) ||
1119 ic->op == JUMPTABLE ||
1125 /* now we need to allocate registers only for the result */
1128 symbol *sym = OP_SYMBOL (IC_RESULT (ic));
1133 D (D_ALLOC, ("serialRegAssign: in loop on result %p\n", sym));
1135 /* Make sure any spill location is definately allocated */
1136 if (sym->isspilt && !sym->remat && sym->usl.spillLoc &&
1137 !sym->usl.spillLoc->allocreq)
1139 sym->usl.spillLoc->allocreq++;
1142 /* if it does not need or is spilt
1143 or is already assigned to registers
1144 or will not live beyond this instructions */
1147 bitVectBitValue (_G.regAssigned, sym->key) ||
1148 sym->liveTo <= ic->seq)
1150 D (D_ALLOC, ("serialRegAssign: wont live long enough.\n"));
1154 /* if some liverange has been spilt at the block level
1155 and this one live beyond this block then spil this
1157 if (_G.blockSpil && sym->liveTo > ebbs[i]->lSeq)
1159 D (D_ALLOC, ("serialRegAssign: \"spilling to be safe.\"\n"));
1163 /* if trying to allocate this will cause
1164 a spill and there is nothing to spill
1165 or this one is rematerializable then
1167 willCS = willCauseSpill (sym->nRegs, sym->regType);
1168 spillable = computeSpillable (ic);
1170 (willCS && bitVectIsZero (spillable)))
1173 D (D_ALLOC, ("serialRegAssign: \"remat spill\"\n"));
1179 /* If the live range preceeds the point of definition
1180 then ideally we must take into account registers that
1181 have been allocated after sym->liveFrom but freed
1182 before ic->seq. This is complicated, so spill this
1183 symbol instead and let fillGaps handle the allocation. */
1184 if (sym->liveFrom < ic->seq)
1190 /* if it has a spillocation & is used less than
1191 all other live ranges then spill this */
1193 if (sym->usl.spillLoc) {
1194 symbol *leastUsed = leastUsedLR (liveRangesWith (spillable,
1195 allLRs, ebbs[i], ic));
1196 if (leastUsed && leastUsed->used > sym->used) {
1201 /* if none of the liveRanges have a spillLocation then better
1202 to spill this one than anything else already assigned to registers */
1203 if (liveRangesWith(spillable,noSpilLoc,ebbs[i],ic)) {
1204 /* if this is local to this block then we might find a block spil */
1205 if (!(sym->liveFrom >= ebbs[i]->fSeq && sym->liveTo <= ebbs[i]->lSeq)) {
1213 /* else we assign registers to it */
1214 _G.regAssigned = bitVectSetBit (_G.regAssigned, sym->key);
1215 _G.totRegAssigned = bitVectSetBit (_G.totRegAssigned, sym->key);
1217 /* Special case: Try to fit into a reg pair if
1219 D (D_ALLOC, ("serialRegAssign: actually allocing regs!\n"));
1220 if ((sym->nRegs == 2) && tryAllocatingRegPair (sym))
1225 for (j = 0; j < sym->nRegs; j++)
1227 sym->regs[j] = getRegGpr (ic, ebbs[i], sym);
1229 /* if the allocation falied which means
1230 this was spilt then break */
1233 D (D_ALLOC, ("Couldnt alloc (spill)\n"))
1237 /* Make sure we didn't allocate a register pair with bytes swapped */
1238 if(sym->nRegs == 2 && sym->regs[0] == sym->regs[1] + 1 && sym->regs[0] != ®sZ80[2])
1240 freeReg(sym->regs[0]);
1241 freeReg(sym->regs[1]);
1242 if(!tryAllocatingRegPair(sym))
1243 wassertl(0, "Failed to swap register pair bytes back.");
1246 /* if it shares registers with operands make sure
1247 that they are in the same position */
1248 if (IC_LEFT (ic) && IS_SYMOP (IC_LEFT (ic)) &&
1249 OP_SYMBOL (IC_LEFT (ic))->nRegs && ic->op != '=')
1250 positionRegs (OP_SYMBOL (IC_RESULT (ic)),
1251 OP_SYMBOL (IC_LEFT (ic)));
1252 /* do the same for the right operand */
1253 if (IC_RIGHT (ic) && IS_SYMOP (IC_RIGHT (ic)) &&
1254 OP_SYMBOL (IC_RIGHT (ic))->nRegs)
1255 positionRegs (OP_SYMBOL (IC_RESULT (ic)),
1256 OP_SYMBOL (IC_RIGHT (ic)));
1262 /* Check for and fix any problems with uninitialized operands */
1263 for (i = 0; i < count; i++)
1267 if (ebbs[i]->noPath &&
1268 (ebbs[i]->entryLabel != entryLabel &&
1269 ebbs[i]->entryLabel != returnLabel))
1272 for (ic = ebbs[i]->sch; ic; ic = ic->next)
1279 verifyRegsAssigned (IC_COND (ic), ic);
1283 if (ic->op == JUMPTABLE)
1285 verifyRegsAssigned (IC_JTCOND (ic), ic);
1289 verifyRegsAssigned (IC_RESULT (ic), ic);
1290 verifyRegsAssigned (IC_LEFT (ic), ic);
1291 verifyRegsAssigned (IC_RIGHT (ic), ic);
1297 /*-----------------------------------------------------------------*/
1298 /* fillGaps - Try to fill in the Gaps left by Pass1 */
1299 /*-----------------------------------------------------------------*/
1300 static void fillGaps()
1305 if (getenv("DISABLE_FILL_GAPS")) return;
1307 /* look for livernages that was spilt by the allocator */
1308 for (sym = hTabFirstItem(liveRanges,&key) ; sym ;
1309 sym = hTabNextItem(liveRanges,&key)) {
1314 if (!sym->spillA || !sym->clashes || sym->remat) continue ;
1316 /* find the liveRanges this one clashes with, that are
1317 still assigned to registers & mark the registers as used*/
1318 for ( i = 0 ; i < sym->clashes->size ; i ++) {
1322 if (bitVectBitValue(sym->clashes,i) == 0 || /* those that clash with this */
1323 bitVectBitValue(_G.totRegAssigned,i) == 0) /* and are still assigned to registers */
1326 clr = hTabItemWithKey(liveRanges,i);
1329 /* mark these registers as used */
1330 for (k = 0 ; k < clr->nRegs ; k++ )
1331 useReg(clr->regs[k]);
1334 if (willCauseSpill(sym->nRegs,sym->regType)) {
1335 /* NOPE :( clear all registers & and continue */
1340 /* THERE IS HOPE !!!! */
1341 for (i=0; i < sym->nRegs ; i++ ) {
1342 sym->regs[i] = getRegGprNoSpil ();
1345 /* for all its definitions check if the registers
1346 allocated needs positioning NOTE: we can position
1347 only ONCE if more than One positioning required
1350 for (i = 0 ; i < sym->defs->size ; i++ ) {
1351 if (bitVectBitValue(sym->defs,i)) {
1353 if (!(ic = hTabItemWithKey(iCodehTab,i))) continue ;
1354 if (SKIP_IC(ic)) continue;
1355 assert(isSymbolEqual(sym,OP_SYMBOL(IC_RESULT(ic)))); /* just making sure */
1356 /* if left is assigned to registers */
1357 if (IS_SYMOP(IC_LEFT(ic)) &&
1358 bitVectBitValue(_G.totRegAssigned,OP_SYMBOL(IC_LEFT(ic))->key)) {
1359 pdone += positionRegs(sym,OP_SYMBOL(IC_LEFT(ic)));
1361 if (IS_SYMOP(IC_RIGHT(ic)) &&
1362 bitVectBitValue(_G.totRegAssigned,OP_SYMBOL(IC_RIGHT(ic))->key)) {
1363 pdone += positionRegs(sym,OP_SYMBOL(IC_RIGHT(ic)));
1365 if (pdone > 1) break;
1368 for (i = 0 ; i < sym->uses->size ; i++ ) {
1369 if (bitVectBitValue(sym->uses,i)) {
1371 if (!(ic = hTabItemWithKey(iCodehTab,i))) continue ;
1372 if (SKIP_IC(ic)) continue;
1373 if (!IS_ASSIGN_ICODE(ic)) continue ;
1375 /* if result is assigned to registers */
1376 if (IS_SYMOP(IC_RESULT(ic)) &&
1377 bitVectBitValue(_G.totRegAssigned,OP_SYMBOL(IC_RESULT(ic))->key)) {
1378 pdone += positionRegs(sym,OP_SYMBOL(IC_RESULT(ic)));
1380 if (pdone > 1) break;
1383 /* had to position more than once GIVE UP */
1385 /* UNDO all the changes we made to try this */
1387 for (i=0; i < sym->nRegs ; i++ ) {
1388 sym->regs[i] = NULL;
1391 D(D_FILL_GAPS,("Fill Gap gave up due to positioning for %s in function %s\n",sym->name, currFunc ? currFunc->name : "UNKNOWN"));
1394 D(D_FILL_GAPS,("FILLED GAP for %s in function %s\n",sym->name, currFunc ? currFunc->name : "UNKNOWN"));
1395 _G.totRegAssigned = bitVectSetBit(_G.totRegAssigned,sym->key);
1396 sym->isspilt = sym->spillA = 0 ;
1397 sym->usl.spillLoc->allocreq--;
1402 /*-----------------------------------------------------------------*/
1403 /* rUmaskForOp :- returns register mask for an operand */
1404 /*-----------------------------------------------------------------*/
1406 rUmaskForOp (operand * op)
1412 /* only temporaries are assigned registers */
1416 sym = OP_SYMBOL (op);
1418 /* if spilt or no registers assigned to it
1420 if (sym->isspilt || !sym->nRegs)
1423 rumask = newBitVect (_G.nRegs);
1425 for (j = 0; j < sym->nRegs; j++)
1427 rumask = bitVectSetBit (rumask, sym->regs[j]->rIdx);
1434 z80_rUmaskForOp (operand * op)
1436 return rUmaskForOp (op);
1439 /** Returns bit vector of registers used in iCode.
1442 regsUsedIniCode (iCode * ic)
1444 bitVect *rmask = newBitVect (_G.nRegs);
1446 /* do the special cases first */
1449 rmask = bitVectUnion (rmask,
1450 rUmaskForOp (IC_COND (ic)));
1454 /* for the jumptable */
1455 if (ic->op == JUMPTABLE)
1457 rmask = bitVectUnion (rmask,
1458 rUmaskForOp (IC_JTCOND (ic)));
1463 /* of all other cases */
1465 rmask = bitVectUnion (rmask,
1466 rUmaskForOp (IC_LEFT (ic)));
1470 rmask = bitVectUnion (rmask,
1471 rUmaskForOp (IC_RIGHT (ic)));
1474 rmask = bitVectUnion (rmask,
1475 rUmaskForOp (IC_RESULT (ic)));
1481 /** For each instruction will determine the regsUsed.
1484 createRegMask (eBBlock ** ebbs, int count)
1488 /* for all blocks */
1489 for (i = 0; i < count; i++)
1493 if (ebbs[i]->noPath &&
1494 (ebbs[i]->entryLabel != entryLabel &&
1495 ebbs[i]->entryLabel != returnLabel))
1498 /* for all instructions */
1499 for (ic = ebbs[i]->sch; ic; ic = ic->next)
1504 if (SKIP_IC2 (ic) || !ic->rlive)
1507 /* first mark the registers used in this
1509 ic->rUsed = regsUsedIniCode (ic);
1510 _G.funcrUsed = bitVectUnion (_G.funcrUsed, ic->rUsed);
1512 /* now create the register mask for those
1513 registers that are in use : this is a
1514 super set of ic->rUsed */
1515 ic->rMask = newBitVect (_G.nRegs + 1);
1517 /* for all live Ranges alive at this point */
1518 for (j = 1; j < ic->rlive->size; j++)
1523 /* if not alive then continue */
1524 if (!bitVectBitValue (ic->rlive, j))
1527 /* find the live range we are interested in */
1528 if (!(sym = hTabItemWithKey (liveRanges, j)))
1530 werror (E_INTERNAL_ERROR, __FILE__, __LINE__,
1531 "createRegMask cannot find live range");
1535 /* if no register assigned to it */
1536 if (!sym->nRegs || sym->isspilt)
1539 /* for all the registers allocated to it */
1540 for (k = 0; k < sym->nRegs; k++)
1543 bitVectSetBit (ic->rMask, sym->regs[k]->rIdx);
1550 /** Returns the rematerialized string for a remat var.
1553 rematStr (symbol * sym)
1555 iCode *ic = sym->rematiCode;
1560 /* if plus adjust offset to right hand side */
1563 offset += (int) operandLitValue (IC_RIGHT (ic));
1564 ic = OP_SYMBOL (IC_LEFT (ic))->rematiCode;
1568 /* if minus adjust offset to right hand side */
1571 offset -= (int) operandLitValue (IC_RIGHT (ic));
1572 ic = OP_SYMBOL (IC_LEFT (ic))->rematiCode;
1576 /* cast then continue */
1577 if (IS_CAST_ICODE(ic)) {
1578 ic = OP_SYMBOL (IC_RIGHT (ic))->rematiCode;
1581 /* we reached the end */
1587 SNPRINTF (buffer, sizeof(buffer),
1589 OP_SYMBOL (IC_LEFT (ic))->rname,
1590 offset >= 0 ? '+' : '-',
1591 abs (offset) & 0xffff);
1595 strncpyz (buffer, OP_SYMBOL (IC_LEFT (ic))->rname, sizeof(buffer));
1601 /*-----------------------------------------------------------------*/
1602 /* regTypeNum - computes the type & number of registers required */
1603 /*-----------------------------------------------------------------*/
1610 /* for each live range do */
1611 for (sym = hTabFirstItem (liveRanges, &k); sym;
1612 sym = hTabNextItem (liveRanges, &k))
1615 /* if used zero times then no registers needed */
1616 if ((sym->liveTo - sym->liveFrom) == 0)
1619 D (D_ALLOC, ("regTypeNum: loop on sym %p\n", sym));
1621 /* if the live range is a temporary */
1625 /* if the type is marked as a conditional */
1626 if (sym->regType == REG_CND)
1629 /* if used in return only then we don't
1631 if (sym->ruonly || sym->accuse)
1633 if (IS_AGGREGATE (sym->type) || sym->isptr)
1634 sym->type = aggrToPtr (sym->type, FALSE);
1638 /* if not then we require registers */
1639 D (D_ALLOC, ("regTypeNum: isagg %u nRegs %u type %p\n", IS_AGGREGATE (sym->type) || sym->isptr, sym->nRegs, sym->type));
1640 sym->nRegs = ((IS_AGGREGATE (sym->type) || sym->isptr) ?
1641 getSize (sym->type = aggrToPtr (sym->type, FALSE)) :
1642 getSize (sym->type));
1643 D (D_ALLOC, ("regTypeNum: setting nRegs of %s (%p) to %u\n", sym->name, sym, sym->nRegs));
1645 D (D_ALLOC, ("regTypeNum: setup to assign regs sym %p\n", sym));
1649 fprintf (stderr, "allocated more than 4 or 0 registers for type ");
1650 printTypeChain (sym->type, stderr);
1651 fprintf (stderr, "\n");
1654 /* determine the type of register required */
1655 /* Always general purpose */
1656 sym->regType = REG_GPR;
1661 /* for the first run we don't provide */
1662 /* registers for true symbols we will */
1663 /* see how things go */
1664 D (D_ALLOC, ("regTypeNum: #2 setting num of %p to 0\n", sym));
1671 /** Mark all registers as free.
1678 D (D_ALLOC, ("freeAllRegs: running.\n"));
1680 for (i = 0; i < _G.nRegs; i++)
1681 regsZ80[i].isFree = 1;
1684 /*-----------------------------------------------------------------*/
1685 /* deallocStackSpil - this will set the stack pointer back */
1686 /*-----------------------------------------------------------------*/
1687 DEFSETFUNC (deallocStackSpil)
1695 /** Register reduction for assignment.
1698 packRegsForAssign (iCode * ic, eBBlock * ebp)
1702 D (D_ALLOC, ("packRegsForAssign: running on ic %p\n", ic));
1704 if (!IS_ITEMP (IC_RIGHT (ic)) ||
1705 OP_SYMBOL (IC_RIGHT (ic))->isind ||
1706 OP_LIVETO (IC_RIGHT (ic)) > ic->seq)
1711 /* find the definition of iTempNN scanning backwards if we find a
1712 a use of the true symbol in before we find the definition then
1714 for (dic = ic->prev; dic; dic = dic->prev)
1716 /* PENDING: Don't pack across function calls. */
1717 if (dic->op == CALL || dic->op == PCALL)
1728 if (IS_SYMOP (IC_COND (dic)) &&
1729 (IC_COND (dic)->key == IC_RESULT (ic)->key ||
1730 IC_COND (dic)->key == IC_RIGHT (ic)->key))
1738 if (IS_TRUE_SYMOP (IC_RESULT (dic)) &&
1739 IS_OP_VOLATILE (IC_RESULT (dic)))
1745 if (IS_SYMOP (IC_RESULT (dic)) &&
1746 IC_RESULT (dic)->key == IC_RIGHT (ic)->key)
1748 if (POINTER_SET (dic))
1754 if (IS_SYMOP (IC_RIGHT (dic)) &&
1755 (IC_RIGHT (dic)->key == IC_RESULT (ic)->key ||
1756 IC_RIGHT (dic)->key == IC_RIGHT (ic)->key))
1762 if (IS_SYMOP (IC_LEFT (dic)) &&
1763 (IC_LEFT (dic)->key == IC_RESULT (ic)->key ||
1764 IC_LEFT (dic)->key == IC_RIGHT (ic)->key))
1770 if (IS_SYMOP (IC_RESULT (dic)) &&
1771 IC_RESULT (dic)->key == IC_RESULT (ic)->key)
1781 return 0; /* did not find */
1783 /* if assignment then check that right is not a bit */
1784 if (ASSIGNMENT (ic) && !POINTER_SET (ic))
1786 sym_link *etype = operandType (IC_RESULT (dic));
1787 if (IS_BITFIELD (etype))
1789 /* if result is a bit too then it's ok */
1790 etype = operandType (IC_RESULT (ic));
1791 if (!IS_BITFIELD (etype))
1798 /* if the result is on stack or iaccess then it must be
1799 the same atleast one of the operands */
1800 if (OP_SYMBOL (IC_RESULT (ic))->onStack ||
1801 OP_SYMBOL (IC_RESULT (ic))->iaccess)
1803 /* the operation has only one symbol
1804 operator then we can pack */
1805 if ((IC_LEFT (dic) && !IS_SYMOP (IC_LEFT (dic))) ||
1806 (IC_RIGHT (dic) && !IS_SYMOP (IC_RIGHT (dic))))
1809 if (!((IC_LEFT (dic) &&
1810 IC_RESULT (ic)->key == IC_LEFT (dic)->key) ||
1812 IC_RESULT (ic)->key == IC_RIGHT (dic)->key)))
1816 /* found the definition */
1817 /* replace the result with the result of */
1818 /* this assignment and remove this assignment */
1819 bitVectUnSetBit(OP_SYMBOL(IC_RESULT(dic))->defs,dic->key);
1820 IC_RESULT (dic) = IC_RESULT (ic);
1822 if (IS_ITEMP (IC_RESULT (dic)) && OP_SYMBOL (IC_RESULT (dic))->liveFrom > dic->seq)
1824 OP_SYMBOL (IC_RESULT (dic))->liveFrom = dic->seq;
1826 /* delete from liverange table also
1827 delete from all the points inbetween and the new
1829 for (sic = dic; sic != ic; sic = sic->next)
1831 bitVectUnSetBit (sic->rlive, IC_RESULT (ic)->key);
1832 if (IS_ITEMP (IC_RESULT (dic)))
1833 bitVectSetBit (sic->rlive, IC_RESULT (dic)->key);
1836 remiCodeFromeBBlock (ebp, ic);
1837 // PENDING: Check vs mcs51
1838 bitVectUnSetBit(OP_SYMBOL(IC_RESULT(ic))->defs,ic->key);
1839 hTabDeleteItem (&iCodehTab, ic->key, ic, DELETE_ITEM, NULL);
1840 OP_DEFS(IC_RESULT (dic))=bitVectSetBit (OP_DEFS (IC_RESULT (dic)), dic->key);
1844 /** Scanning backwards looks for first assig found.
1847 findAssignToSym (operand * op, iCode * ic)
1851 for (dic = ic->prev; dic; dic = dic->prev)
1854 /* if definition by assignment */
1855 if (dic->op == '=' &&
1856 !POINTER_SET (dic) &&
1857 IC_RESULT (dic)->key == op->key)
1858 /* && IS_TRUE_SYMOP(IC_RIGHT(dic)) */
1861 /* we are interested only if defined in far space */
1862 /* or in stack space in case of + & - */
1864 /* if assigned to a non-symbol then return
1866 if (!IS_SYMOP (IC_RIGHT (dic)))
1869 /* if the symbol is in far space then
1871 if (isOperandInFarSpace (IC_RIGHT (dic)))
1874 /* for + & - operations make sure that
1875 if it is on the stack it is the same
1876 as one of the three operands */
1877 if ((ic->op == '+' || ic->op == '-') &&
1878 OP_SYMBOL (IC_RIGHT (dic))->onStack)
1881 if (IC_RESULT (ic)->key != IC_RIGHT (dic)->key &&
1882 IC_LEFT (ic)->key != IC_RIGHT (dic)->key &&
1883 IC_RIGHT (ic)->key != IC_RIGHT (dic)->key)
1891 /* if we find an usage then we cannot delete it */
1892 if (IC_LEFT (dic) && IC_LEFT (dic)->key == op->key)
1895 if (IC_RIGHT (dic) && IC_RIGHT (dic)->key == op->key)
1898 if (POINTER_SET (dic) && IC_RESULT (dic)->key == op->key)
1902 /* now make sure that the right side of dic
1903 is not defined between ic & dic */
1906 iCode *sic = dic->next;
1908 for (; sic != ic; sic = sic->next)
1909 if (IC_RESULT (sic) &&
1910 IC_RESULT (sic)->key == IC_RIGHT (dic)->key)
1919 #if !DISABLE_PACKREGSFORSUPPORT
1922 /*-----------------------------------------------------------------*/
1923 /* packRegsForSupport :- reduce some registers for support calls */
1924 /*-----------------------------------------------------------------*/
1926 packRegsForSupport (iCode * ic, eBBlock * ebp)
1929 /* for the left & right operand :- look to see if the
1930 left was assigned a true symbol in far space in that
1931 case replace them */
1932 D (D_ALLOC, ("packRegsForSupport: running on ic %p\n", ic));
1934 if (IS_ITEMP (IC_LEFT (ic)) &&
1935 OP_SYMBOL (IC_LEFT (ic))->liveTo <= ic->seq)
1937 iCode *dic = findAssignToSym (IC_LEFT (ic), ic);
1943 /* found it we need to remove it from the
1945 for (sic = dic; sic != ic; sic = sic->next)
1946 bitVectUnSetBit (sic->rlive, IC_LEFT (ic)->key);
1948 IC_LEFT (ic)->operand.symOperand =
1949 IC_RIGHT (dic)->operand.symOperand;
1950 IC_LEFT (ic)->key = IC_RIGHT (dic)->operand.symOperand->key;
1951 remiCodeFromeBBlock (ebp, dic);
1952 bitVectUnSetBit(OP_SYMBOL(IC_RESULT(dic))->defs,dic->key);
1953 hTabDeleteItem (&iCodehTab, dic->key, dic, DELETE_ITEM, NULL);
1954 // PENDING: Check vs mcs51
1958 /* do the same for the right operand */
1961 IS_ITEMP (IC_RIGHT (ic)) &&
1962 OP_SYMBOL (IC_RIGHT (ic))->liveTo <= ic->seq)
1964 iCode *dic = findAssignToSym (IC_RIGHT (ic), ic);
1970 /* found it we need to remove it from the block */
1971 for (sic = dic; sic != ic; sic = sic->next)
1972 bitVectUnSetBit (sic->rlive, IC_RIGHT (ic)->key);
1974 IC_RIGHT (ic)->operand.symOperand =
1975 IC_RIGHT (dic)->operand.symOperand;
1976 IC_RIGHT (ic)->key = IC_RIGHT (dic)->operand.symOperand->key;
1978 remiCodeFromeBBlock (ebp, dic);
1979 bitVectUnSetBit(OP_SYMBOL(IC_RESULT(dic))->defs,dic->key);
1980 hTabDeleteItem (&iCodehTab, dic->key, dic, DELETE_ITEM, NULL);
1981 // PENDING: vs mcs51
1989 /** Will reduce some registers for single use.
1992 packRegsForOneuse (iCode * ic, operand * op, eBBlock * ebp)
1998 D (D_ALLOC, ("packRegsForOneUse: running on ic %p\n", ic));
2000 /* if returning a literal then do nothing */
2004 /* only upto 2 bytes since we cannot predict
2005 the usage of b, & acc */
2006 if (getSize (operandType (op)) > 2)
2009 if (ic->op != RETURN &&
2013 /* this routine will mark the a symbol as used in one
2014 instruction use only && if the defintion is local
2015 (ie. within the basic block) && has only one definition &&
2016 that definiion is either a return value from a
2017 function or does not contain any variables in
2019 uses = bitVectCopy (OP_USES (op));
2020 bitVectUnSetBit (uses, ic->key); /* take away this iCode */
2021 if (!bitVectIsZero (uses)) /* has other uses */
2024 /* if it has only one defintion */
2025 if (bitVectnBitsOn (OP_DEFS (op)) > 1)
2026 return NULL; /* has more than one definition */
2028 /* get the that definition */
2030 hTabItemWithKey (iCodehTab,
2031 bitVectFirstBit (OP_DEFS (op)))))
2034 /* found the definition now check if it is local */
2035 if (dic->seq < ebp->fSeq ||
2036 dic->seq > ebp->lSeq)
2037 return NULL; /* non-local */
2039 /* now check if it is the return from a function call */
2040 if (dic->op == CALL || dic->op == PCALL)
2042 if (ic->op != SEND && ic->op != RETURN &&
2043 !POINTER_SET(ic) && !POINTER_GET(ic))
2045 OP_SYMBOL (op)->ruonly = 1;
2051 /* otherwise check that the definition does
2052 not contain any symbols in far space */
2053 if (isOperandInFarSpace (IC_LEFT (dic)) ||
2054 isOperandInFarSpace (IC_RIGHT (dic)) ||
2055 IS_OP_RUONLY (IC_LEFT (ic)) ||
2056 IS_OP_RUONLY (IC_RIGHT (ic)))
2061 /* if pointer set then make sure the pointer is one byte */
2062 if (POINTER_SET (dic))
2065 if (POINTER_GET (dic))
2070 /* also make sure the intervenening instructions
2071 don't have any thing in far space */
2072 for (dic = dic->next; dic && dic != ic; dic = dic->next)
2074 /* if there is an intervening function call then no */
2075 if (dic->op == CALL || dic->op == PCALL)
2077 /* if pointer set then make sure the pointer
2079 if (POINTER_SET (dic))
2082 if (POINTER_GET (dic))
2085 /* if address of & the result is remat the okay */
2086 if (dic->op == ADDRESS_OF &&
2087 OP_SYMBOL (IC_RESULT (dic))->remat)
2090 /* if left or right or result is in far space */
2091 if (isOperandInFarSpace (IC_LEFT (dic)) ||
2092 isOperandInFarSpace (IC_RIGHT (dic)) ||
2093 isOperandInFarSpace (IC_RESULT (dic)) ||
2094 IS_OP_RUONLY (IC_LEFT (dic)) ||
2095 IS_OP_RUONLY (IC_RIGHT (dic)) ||
2096 IS_OP_RUONLY (IC_RESULT (dic)))
2102 OP_SYMBOL (op)->ruonly = 1;
2106 /*-----------------------------------------------------------------*/
2107 /* isBitwiseOptimizable - requirements of JEAN LOUIS VERN */
2108 /*-----------------------------------------------------------------*/
2110 isBitwiseOptimizable (iCode * ic)
2112 sym_link *rtype = getSpec (operandType (IC_RIGHT (ic)));
2114 /* bitwise operations are considered optimizable
2115 under the following conditions (Jean-Louis VERN)
2127 if (IS_LITERAL (rtype))
2133 Certian assignments involving pointers can be temporarly stored
2144 #if !DISABLE_PACKREGSFORACCUSE
2147 /** Pack registers for acc use.
2148 When the result of this operation is small and short lived it may
2149 be able to be stored in the accumelator.
2152 packRegsForAccUse (iCode * ic)
2156 /* if this is an aggregate, e.g. a one byte char array */
2157 if (IS_AGGREGATE(operandType(IC_RESULT(ic)))) {
2161 /* if + or - then it has to be one byte result */
2162 if ((ic->op == '+' || ic->op == '-')
2163 && getSize (operandType (IC_RESULT (ic))) > 1)
2166 /* if shift operation make sure right side is not a literal */
2167 if (ic->op == RIGHT_OP &&
2168 (isOperandLiteral (IC_RIGHT (ic)) ||
2169 getSize (operandType (IC_RESULT (ic))) > 1))
2172 if (ic->op == LEFT_OP &&
2173 (isOperandLiteral (IC_RIGHT (ic)) ||
2174 getSize (operandType (IC_RESULT (ic))) > 1))
2177 /* has only one definition */
2178 if (bitVectnBitsOn (OP_DEFS (IC_RESULT (ic))) > 1)
2181 /* has only one use */
2182 if (bitVectnBitsOn (OP_USES (IC_RESULT (ic))) > 1)
2185 /* and the usage immediately follows this iCode */
2186 if (!(uic = hTabItemWithKey (iCodehTab,
2187 bitVectFirstBit (OP_USES (IC_RESULT (ic))))))
2190 if (ic->next != uic)
2193 /* if it is a conditional branch then we definitely can */
2197 if (uic->op == JUMPTABLE)
2201 /* if the usage is not is an assignment or an
2202 arithmetic / bitwise / shift operation then not */
2203 if (POINTER_SET (uic) &&
2204 getSize (aggrToPtr (operandType (IC_RESULT (uic)), FALSE)) > 1)
2208 if (uic->op != '=' &&
2209 !IS_ARITHMETIC_OP (uic) &&
2210 !IS_BITWISE_OP (uic) &&
2211 uic->op != LEFT_OP &&
2212 uic->op != RIGHT_OP)
2215 /* if used in ^ operation then make sure right is not a
2217 if (uic->op == '^' && isOperandLiteral (IC_RIGHT (uic)))
2220 /* if shift operation make sure right side is not a literal */
2221 if (uic->op == RIGHT_OP &&
2222 (isOperandLiteral (IC_RIGHT (uic)) ||
2223 getSize (operandType (IC_RESULT (uic))) > 1))
2226 if (uic->op == LEFT_OP &&
2227 (isOperandLiteral (IC_RIGHT (uic)) ||
2228 getSize (operandType (IC_RESULT (uic))) > 1))
2232 /* make sure that the result of this icode is not on the
2233 stack, since acc is used to compute stack offset */
2234 if (IS_TRUE_SYMOP (IC_RESULT (uic)) &&
2235 OP_SYMBOL (IC_RESULT (uic))->onStack)
2240 /* if either one of them in far space then we cannot */
2241 if ((IS_TRUE_SYMOP (IC_LEFT (uic)) &&
2242 isOperandInFarSpace (IC_LEFT (uic))) ||
2243 (IS_TRUE_SYMOP (IC_RIGHT (uic)) &&
2244 isOperandInFarSpace (IC_RIGHT (uic))))
2248 /* if the usage has only one operand then we can */
2249 if (IC_LEFT (uic) == NULL ||
2250 IC_RIGHT (uic) == NULL)
2253 /* make sure this is on the left side if not
2254 a '+' since '+' is commutative */
2255 if (ic->op != '+' &&
2256 IC_LEFT (uic)->key != IC_RESULT (ic)->key)
2259 // See mcs51 ralloc for reasoning
2261 /* if one of them is a literal then we can */
2262 if ((IC_LEFT (uic) && IS_OP_LITERAL (IC_LEFT (uic))) ||
2263 (IC_RIGHT (uic) && IS_OP_LITERAL (IC_RIGHT (uic))))
2270 /** This is confusing :) Guess for now */
2271 if (IC_LEFT (uic)->key == IC_RESULT (ic)->key &&
2272 (IS_ITEMP (IC_RIGHT (uic)) ||
2273 (IS_TRUE_SYMOP (IC_RIGHT (uic)))))
2276 if (IC_RIGHT (uic)->key == IC_RESULT (ic)->key &&
2277 (IS_ITEMP (IC_LEFT (uic)) ||
2278 (IS_TRUE_SYMOP (IC_LEFT (uic)))))
2282 OP_SYMBOL (IC_RESULT (ic))->accuse = ACCUSE_A;
2287 packRegsForHLUse (iCode * ic)
2291 /* PENDING: Could do IFX */
2297 /* has only one definition */
2298 if (bitVectnBitsOn (OP_DEFS (IC_RESULT (ic))) > 1)
2300 D (D_HLUSE, (" + Dropping as has more than one def\n"));
2304 /* has only one use */
2305 if (bitVectnBitsOn (OP_USES (IC_RESULT (ic))) > 1)
2307 D (D_HLUSE, (" + Dropping as has more than one use\n"));
2311 /* and the usage immediately follows this iCode */
2312 if (!(uic = hTabItemWithKey (iCodehTab,
2313 bitVectFirstBit (OP_USES (IC_RESULT (ic))))))
2315 D (D_HLUSE, (" + Dropping as usage isn't in this block\n"));
2319 if (ic->next != uic)
2321 D (D_HLUSE, (" + Dropping as usage doesn't follow this\n"));
2330 if (getSize (operandType (IC_RESULT (ic))) != 2 ||
2331 (IC_LEFT(uic) && getSize (operandType (IC_LEFT (uic))) != 2) ||
2332 (IC_RIGHT(uic) && getSize (operandType (IC_RIGHT (uic))) != 2))
2334 D (D_HLUSE, (" + Dropping as the result size is not 2\n"));
2340 if (ic->op == CAST && uic->op == IPUSH)
2342 if (ic->op == ADDRESS_OF && uic->op == IPUSH)
2344 if (ic->op == ADDRESS_OF && POINTER_GET (uic) && IS_ITEMP( IC_RESULT (uic)))
2346 if (ic->op == CALL && ic->parmBytes == 0 && (uic->op == '-' || uic->op == '+'))
2351 /* Case of assign a constant to offset in a static array. */
2352 if (ic->op == '+' && IS_VALOP (IC_RIGHT (ic)))
2354 if (uic->op == '=' && POINTER_SET (uic))
2358 else if (uic->op == IPUSH && getSize (operandType (IC_LEFT (uic))) == 2)
2365 D (D_HLUSE, (" + Dropping as it's a bad op\n"));
2368 OP_SYMBOL (IC_RESULT (ic))->accuse = ACCUSE_SCRATCH;
2372 packRegsForHLUse3 (iCode * lic, operand * op, eBBlock * ebp)
2377 bool isFirst = TRUE;
2379 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));
2383 if ( OP_SYMBOL(op)->accuse)
2388 if (OP_SYMBOL(op)->remat)
2393 /* Only defined once */
2394 if (bitVectnBitsOn (OP_DEFS (op)) > 1)
2397 if (getSize (operandType (op)) > 2)
2400 /* And this is the definition */
2401 if (bitVectFirstBit (OP_DEFS (op)) != lic->key)
2404 /* first check if any overlapping liverange has already been
2406 if (OP_SYMBOL(op)->clashes)
2408 for (i = 0 ; i < OP_SYMBOL(op)->clashes->size ; i++ )
2410 if (bitVectBitValue(OP_SYMBOL(op)->clashes,i))
2412 sym = hTabItemWithKey(liveRanges,i);
2413 if (sym->accuse == ACCUSE_SCRATCH)
2421 /* Nothing else that clashes with this is using the scratch
2422 register. Scan through all of the intermediate instructions and
2423 see if any of them could nuke HL.
2425 dic = ic = hTabFirstItemWK(iCodeSeqhTab,OP_SYMBOL(op)->liveFrom);
2427 for (; ic && ic->seq <= OP_SYMBOL(op)->liveTo;
2428 ic = hTabNextItem(iCodeSeqhTab, &key))
2432 D (D_PACK_HLUSE3, ("(On %p: op: %u next: %p)\n", ic, ic->op, ic->next));
2437 if (ic->op == ADDRESS_OF)
2439 if (POINTER_GET (ic))
2441 if (ic->op == '=' && !POINTER_SET(ic))
2445 if (IC_RESULT(ic) && IS_SYMOP(IC_RESULT(ic))
2446 && isOperandInDirSpace (IC_RESULT (ic)))
2449 if (IC_LEFT(ic) && IS_SYMOP(IC_LEFT(ic))
2450 && isOperandInDirSpace (IC_LEFT (ic)))
2453 if (IC_RIGHT(ic) && IS_SYMOP(IC_RIGHT(ic))
2454 && isOperandInDirSpace (IC_RIGHT (ic)))
2457 /* Handle the non left/right/result ones first */
2460 if (ic->op == JUMPTABLE)
2469 if (ic->op == IPUSH && isOperandEqual (op, IC_LEFT (ic)))
2472 if (ic->op == SEND && isOperandEqual (op, IC_LEFT (ic)))
2475 if (ic->op == CALL && isOperandEqual (op, IC_RESULT (ic)))
2478 if (ic->op == LEFT_OP && isOperandLiteral (IC_RIGHT (ic)))
2481 if (ic->op == '+' &&
2482 (isOperandEqual (op, IC_LEFT (ic)) || isOperandEqual (op, IC_RIGHT (ic))))
2485 if ((ic->op == '=' && !POINTER_SET(ic)) ||
2486 ic->op == UNARYMINUS ||
2491 (ic->op == '+' && getSize (operandType (IC_RESULT (ic))) == 1))
2492 /* 16 bit addition uses add hl, rr */
2495 if (ic->op == '*' && isOperandEqual (op, IC_LEFT (ic)))
2498 if (POINTER_SET (ic) && isOperandEqual (op, IC_RESULT (ic)))
2501 if (POINTER_GET (ic) && isOperandEqual (op, IC_LEFT (ic)))
2504 if (IS_VALOP (IC_RIGHT (ic)) &&
2511 /* By default give up */
2515 D (D_PACK_HLUSE3, ("Succeeded!\n"))
2517 OP_SYMBOL (op)->accuse = ACCUSE_SCRATCH;
2522 packRegsForIYUse (iCode * lic, operand * op, eBBlock * ebp)
2529 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));
2533 if ( OP_SYMBOL(op)->accuse)
2538 if (OP_SYMBOL(op)->remat)
2543 /* Only defined once */
2544 if (bitVectnBitsOn (OP_DEFS (op)) > 1)
2547 /* And this is the definition */
2548 if (bitVectFirstBit (OP_DEFS (op)) != lic->key)
2551 /* first check if any overlapping liverange has already been
2553 if (OP_SYMBOL(op)->clashes)
2555 for (i = 0 ; i < OP_SYMBOL(op)->clashes->size ; i++ )
2557 if (bitVectBitValue(OP_SYMBOL(op)->clashes,i))
2559 sym = hTabItemWithKey(liveRanges,i);
2560 if (sym->accuse == ACCUSE_IY)
2568 /* Only a few instructions can load into IY */
2574 if (getSize (operandType (op)) != 2)
2576 D (D_ACCUSE2, (" + Dropping as operation has size is too big\n"));
2580 /* Nothing else that clashes with this is using the scratch
2581 register. Scan through all of the intermediate instructions and
2582 see if any of them could nuke HL.
2584 dic = ic = hTabFirstItemWK(iCodeSeqhTab,OP_SYMBOL(op)->liveFrom);
2587 for (; ic && ic->seq <= OP_SYMBOL(op)->liveTo;
2588 ic = hTabNextItem(iCodeSeqhTab,&key))
2593 if (ic->op == PCALL ||
2602 /* Be pessamistic. */
2606 D (D_PACK_IY, (" op: %u uses %u result: %d left: %d right: %d\n", ic->op, bitVectBitValue(uses, ic->key),
2607 IC_RESULT(ic) && IS_SYMOP(IC_RESULT(ic)) ? isOperandInDirSpace(IC_RESULT(ic)) : -1,
2608 IC_LEFT(ic) && IS_SYMOP(IC_LEFT(ic)) ? isOperandInDirSpace(IC_LEFT(ic)) : -1,
2609 IC_RIGHT(ic) && IS_SYMOP(IC_RIGHT(ic)) ? isOperandInDirSpace(IC_RIGHT(ic)) : -1
2612 if (IC_RESULT(ic) && IS_SYMOP(IC_RESULT(ic)) &&
2613 isOperandInDirSpace(IC_RESULT(ic)))
2616 if (IC_RIGHT(ic) && IS_SYMOP(IC_RIGHT(ic)) &&
2617 isOperandInDirSpace(IC_RIGHT(ic)))
2620 if (IC_LEFT(ic) && IS_SYMOP(IC_LEFT(ic)) &&
2621 isOperandInDirSpace(IC_LEFT(ic)))
2624 /* Only certain rules will work against IY. Check if this iCode uses
2626 if (bitVectBitValue(uses, ic->key) != 0)
2628 if (ic->op == '=' &&
2629 isOperandEqual(IC_RESULT(ic), op))
2632 if (ic->op == GET_VALUE_AT_ADDRESS &&
2633 isOperandEqual(IC_LEFT(ic), op))
2636 if (isOperandEqual(IC_RESULT(ic), IC_LEFT(ic)) == FALSE)
2639 if (IC_RIGHT (ic) && IS_VALOP (IC_RIGHT (ic)))
2641 if (ic->op == '+' ||
2644 /* Only works if the constant is small */
2645 if (operandLitValue (IC_RIGHT (ic)) < 4)
2654 /* This iCode doesn't use the sym. See if this iCode preserves IY.
2659 /* By default give up */
2663 D (D_PACK_IY, ("Succeeded IY!\n"));
2665 OP_SYMBOL (op)->accuse = ACCUSE_IY;
2669 /** Returns TRUE if this operation can use acc and if it preserves the value.
2672 opPreservesA (iCode * uic)
2676 /* If we've gotten this far then the thing to compare must be
2677 small enough and must be in A.
2682 if (uic->op == JUMPTABLE)
2684 D (D_ACCUSE2, (" + Dropping as operation is a Jumptable\n"));
2688 /* A pointer assign preserves A if A is the left value. */
2689 if (uic->op == '=' && POINTER_SET (uic))
2694 /* if the usage has only one operand then we can */
2695 /* PENDING: check */
2696 if (IC_LEFT (uic) == NULL ||
2697 IC_RIGHT (uic) == NULL)
2699 D (D_ACCUSE2, (" + Dropping as operation has only one operand\n"));
2703 /* PENDING: check this rule */
2704 if (getSize (operandType (IC_RESULT (uic))) > 1)
2706 D (D_ACCUSE2, (" + Dropping as operation has size is too big\n"));
2711 /* Disabled all of the old rules as they weren't verified and have
2712 caused at least one problem.
2717 /** Returns true if this operand preserves the value of A.
2720 opIgnoresA (iCode * ic, iCode * uic)
2722 /* A increment of an iTemp by a constant is OK. */
2723 if ( uic->op == '+' &&
2724 IS_ITEMP (IC_LEFT (uic)) &&
2725 IS_ITEMP (IC_RESULT (uic)) &&
2726 IS_OP_LITERAL (IC_RIGHT (uic)))
2728 unsigned int icount = (unsigned int) ulFromVal (IC_RIGHT (uic)->operand.valOperand);
2730 /* Being an ITEMP means that we're already a symbol. */
2732 IC_RESULT (uic)->operand.symOperand->key == IC_LEFT (uic)->operand.symOperand->key
2738 else if (uic->op == '=' && !POINTER_SET (uic))
2740 /* If they are equal and get optimised out then things are OK. */
2741 if (isOperandEqual (IC_RESULT (uic), IC_RIGHT (uic)))
2743 /* Straight assign is OK. */
2752 /* Some optimisation cases:
2764 ; genAssign (pointer)
2768 want to optimise down to:
2774 So genPointer get is OK
2775 genPlus where the right is constant, left is iTemp, and result is same as left
2776 genAssign (pointer) is OK
2787 ; genAssign (pointer)
2788 ; AOP_STK for _strcpy_to_1_1
2793 want to optimise down to:
2799 So genIfx where IC_COND has size of 1 and is a constant.
2802 /** Pack registers for acc use.
2803 When the result of this operation is small and short lived it may
2804 be able to be stored in the accumulator.
2806 Note that the 'A preserving' list is currently emperical :)
2809 packRegsForAccUse2 (iCode * ic)
2813 D (D_ACCUSE2, ("packRegsForAccUse2: running on ic %p line %u\n", ic, ic->lineno));
2817 /* Filter out all but those 'good' commands */
2819 !POINTER_GET (ic) &&
2822 !IS_BITWISE_OP (ic) &&
2828 ic->op != GETHBIT &&
2831 D (D_ACCUSE2, (" + Dropping as not a 'good' source command\n"));
2835 /* if + or - then it has to be one byte result.
2838 if ((ic->op == '+' || ic->op == '-')
2839 && getSize (operandType (IC_RESULT (ic))) > 1)
2841 D (D_ACCUSE2, (" + Dropping as it's a big + or -\n"));
2845 /* has only one definition */
2846 if (bitVectnBitsOn (OP_DEFS (IC_RESULT (ic))) > 1)
2848 D (D_ACCUSE2, (" + Dropping as it has more than one definition\n"));
2852 /* Right. We may be able to propagate it through if:
2853 For each in the chain of uses the intermediate is OK.
2855 /* Get next with 'uses result' bit on
2856 If this->next == next
2857 Validate use of next
2858 If OK, increase count
2860 /* and the usage immediately follows this iCode */
2861 if (!(uic = hTabItemWithKey (iCodehTab,
2862 bitVectFirstBit (OP_USES (IC_RESULT (ic))))))
2864 D (D_ACCUSE2, (" + Dropping as usage does not follow first\n"));
2869 /* Create a copy of the OP_USES bit vect */
2870 bitVect *uses = bitVectCopy (OP_USES (IC_RESULT (ic)));
2872 iCode *scan = ic, *next;
2876 setBit = bitVectFirstBit (uses);
2877 next = hTabItemWithKey (iCodehTab, setBit);
2878 if (scan->next == next)
2880 D (D_ACCUSE2_VERBOSE, (" ! Is next in line\n"));
2882 bitVectUnSetBit (uses, setBit);
2883 /* Still contigous. */
2884 if (!opPreservesA (next))
2886 D (D_ACCUSE2, (" + Dropping as operation doesn't preserve A\n"));
2889 D (D_ACCUSE2_VERBOSE, (" ! Preserves A, so continue scanning\n"));
2892 /*else if (scan->next == NULL && bitVectnBitsOn (uses) == 1 && next != NULL)
2894 if (next->prev == NULL)
2896 if (!opPreservesA (next))
2898 D (D_ACCUSE2, (" + Dropping as operation doesn't preserve A #2\n"));
2901 bitVectUnSetBit (uses, setBit);
2906 D (D_ACCUSE2, (" + Dropping as last in list and next doesn't start a block\n"));
2909 } //This caused bug #1292721 */
2910 else if (scan->next == NULL)
2912 D (D_ACCUSE2, (" + Dropping as hit the end of the list\n"));
2913 D (D_ACCUSE2, (" + Next in htab: %p\n", next));
2918 if (opIgnoresA (ic, scan->next))
2922 D (D_ACCUSE2_VERBOSE, (" ! Op ignores A, so continue scanning\n"));
2926 D (D_ACCUSE2, (" + Dropping as parts are not consecuitive and intermediate might use A\n"));
2931 while (!bitVectIsZero (uses));
2933 OP_SYMBOL (IC_RESULT (ic))->accuse = ACCUSE_A;
2938 /** Does some transformations to reduce register pressure.
2941 packRegisters (eBBlock * ebp)
2946 D (D_ALLOC, ("packRegisters: entered.\n"));
2948 while (1 && !DISABLE_PACK_ASSIGN)
2951 /* look for assignments of the form */
2952 /* iTempNN = TRueSym (someoperation) SomeOperand */
2954 /* TrueSym := iTempNN:1 */
2955 for (ic = ebp->sch; ic; ic = ic->next)
2957 /* find assignment of the form TrueSym := iTempNN:1 */
2958 if (ic->op == '=' && !POINTER_SET (ic))
2959 change += packRegsForAssign (ic, ebp);
2965 for (ic = ebp->sch; ic; ic = ic->next)
2967 /* Safe: address of a true sym is always constant. */
2968 /* if this is an itemp & result of a address of a true sym
2969 then mark this as rematerialisable */
2970 D (D_ALLOC, ("packRegisters: looping on ic %p\n", ic));
2972 if (ic->op == ADDRESS_OF &&
2973 IS_ITEMP (IC_RESULT (ic)) &&
2974 IS_TRUE_SYMOP (IC_LEFT (ic)) &&
2975 bitVectnBitsOn (OP_DEFS (IC_RESULT (ic))) == 1 &&
2976 !OP_SYMBOL (IC_LEFT (ic))->onStack)
2979 OP_SYMBOL (IC_RESULT (ic))->remat = 1;
2980 OP_SYMBOL (IC_RESULT (ic))->rematiCode = ic;
2981 OP_SYMBOL (IC_RESULT (ic))->usl.spillLoc = NULL;
2984 /* Safe: just propagates the remat flag */
2985 /* if straight assignment then carry remat flag if this is the
2987 if (ic->op == '=' &&
2988 !POINTER_SET (ic) &&
2989 IS_SYMOP (IC_RIGHT (ic)) &&
2990 OP_SYMBOL (IC_RIGHT (ic))->remat &&
2991 !IS_CAST_ICODE(OP_SYMBOL (IC_RIGHT (ic))->rematiCode) &&
2992 !isOperandGlobal(IC_RESULT(ic)) && /* due to bug 1618050 */
2993 bitVectnBitsOn (OP_SYMBOL (IC_RESULT (ic))->defs) <= 1)
2995 OP_SYMBOL (IC_RESULT (ic))->remat =
2996 OP_SYMBOL (IC_RIGHT (ic))->remat;
2997 OP_SYMBOL (IC_RESULT (ic))->rematiCode =
2998 OP_SYMBOL (IC_RIGHT (ic))->rematiCode;
3001 /* if the condition of an if instruction is defined in the
3002 previous instruction then mark the itemp as a conditional */
3003 if ((IS_CONDITIONAL (ic) ||
3004 ((ic->op == BITWISEAND ||
3007 isBitwiseOptimizable (ic))) &&
3008 ic->next && ic->next->op == IFX &&
3009 bitVectnBitsOn (OP_USES(IC_RESULT(ic)))==1 &&
3010 isOperandEqual (IC_RESULT (ic), IC_COND (ic->next)) &&
3011 OP_SYMBOL (IC_RESULT (ic))->liveTo <= ic->next->seq)
3014 OP_SYMBOL (IC_RESULT (ic))->regType = REG_CND;
3019 /* reduce for support function calls */
3020 if (ic->supportRtn || ic->op == '+' || ic->op == '-')
3021 packRegsForSupport (ic, ebp);
3024 /* some cases the redundant moves can
3025 can be eliminated for return statements */
3026 if (ic->op == RETURN || ic->op == SEND)
3028 packRegsForOneuse (ic, IC_LEFT (ic), ebp);
3031 /* if pointer set & left has a size more than
3032 one and right is not in far space */
3033 if (!DISABLE_PACK_ONE_USE &&
3035 /* MLH: no such thing.
3036 !isOperandInFarSpace(IC_RIGHT(ic)) && */
3037 !OP_SYMBOL (IC_RESULT (ic))->remat &&
3038 !IS_OP_RUONLY (IC_RIGHT (ic)) &&
3039 getSize (aggrToPtr (operandType (IC_RESULT (ic)), FALSE)) > 1)
3042 packRegsForOneuse (ic, IC_RESULT (ic), ebp);
3045 /* if pointer get */
3046 if (!DISABLE_PACK_ONE_USE &&
3048 IS_SYMOP (IC_LEFT (ic)) &&
3049 /* MLH: dont have far space
3050 !isOperandInFarSpace(IC_RESULT(ic))&& */
3051 !OP_SYMBOL (IC_LEFT (ic))->remat &&
3052 !IS_OP_RUONLY (IC_RESULT (ic)) &&
3053 getSize (aggrToPtr (operandType (IC_LEFT (ic)), FALSE)) > 1)
3056 packRegsForOneuse (ic, IC_LEFT (ic), ebp);
3059 /* pack registers for accumulator use, when the result of an
3060 arithmetic or bit wise operation has only one use, that use is
3061 immediately following the defintion and the using iCode has
3062 only one operand or has two operands but one is literal & the
3063 result of that operation is not on stack then we can leave the
3064 result of this operation in acc:b combination */
3066 if (!DISABLE_PACK_HL && IS_ITEMP (IC_RESULT (ic)))
3072 packRegsForHLUse (ic);
3076 packRegsForHLUse3 (ic, IC_RESULT (ic), ebp);
3080 if (!DISABLE_PACK_IY && IS_ITEMP (IC_RESULT (ic)) && IS_Z80)
3082 packRegsForIYUse (ic, IC_RESULT (ic), ebp);
3085 if (!DISABLE_PACK_ACC && IS_ITEMP (IC_RESULT (ic)) &&
3086 getSize (operandType (IC_RESULT (ic))) == 1)
3088 packRegsForAccUse2 (ic);
3093 /** Joins together two byte constant pushes into one word push.
3096 joinPushes (iCode *lic)
3100 for (ic = lic; ic; ic = ic->next)
3107 /* Anything past this? */
3112 /* This and the next pushes? */
3113 if (ic->op != IPUSH || uic->op != IPUSH)
3117 /* Both literals? */
3118 if ( !IS_OP_LITERAL (IC_LEFT (ic)) || !IS_OP_LITERAL (IC_LEFT (uic)))
3122 /* Both characters? */
3123 if ( getSize (operandType (IC_LEFT (ic))) != 1 || getSize (operandType (IC_LEFT (uic))) != 1)
3127 /* Pull out the values, make a new type, and create the new iCode for it.
3129 first = (int)operandLitValue ( IC_LEFT (ic));
3130 second = (int)operandLitValue ( IC_LEFT (uic));
3132 sprintf (buffer, "%uu", ((first << 8) | (second & 0xFF)) & 0xFFFFU);
3133 val = constVal (buffer);
3134 SPEC_NOUN (val->type) = V_INT;
3135 IC_LEFT (ic) = operandFromOperand (IC_LEFT (ic));
3136 IC_LEFT (ic)->operand.valOperand = val;
3138 /* Now remove the second one from the list. */
3139 ic->next = uic->next;
3142 /* Patch up the reverse link */
3143 uic->next->prev = ic;
3150 /*-----------------------------------------------------------------*/
3151 /* assignRegisters - assigns registers to each live range as need */
3152 /*-----------------------------------------------------------------*/
3154 z80_assignRegisters (ebbIndex * ebbi)
3156 eBBlock ** ebbs = ebbi->bbOrder;
3157 int count = ebbi->count;
3161 D (D_ALLOC, ("\n-> z80_assignRegisters: entered.\n"));
3163 setToNull ((void *) &_G.funcrUsed);
3164 setToNull ((void *) &_G.totRegAssigned);
3165 _G.stackExtend = _G.dataExtend = 0;
3169 /* DE is required for the code gen. */
3170 _G.nRegs = GBZ80_MAX_REGS;
3171 regsZ80 = _gbz80_regs;
3175 _G.nRegs = Z80_MAX_REGS;
3176 regsZ80 = _z80_regs;
3179 /* change assignments this will remove some
3180 live ranges reducing some register pressure */
3181 for (i = 0; i < count; i++)
3182 packRegisters (ebbs[i]);
3184 /* liveranges probably changed by register packing
3185 so we compute them again */
3186 recomputeLiveRanges (ebbs, count);
3188 if (options.dump_pack)
3189 dumpEbbsToFileExt (DUMP_PACK, ebbi);
3191 /* first determine for each live range the number of
3192 registers & the type of registers required for each */
3195 /* and serially allocate registers */
3196 serialRegAssign (ebbs, count);
3201 /* if stack was extended then tell the user */
3204 /* werror(W_TOOMANY_SPILS,"stack", */
3205 /* _G.stackExtend,currFunc->name,""); */
3211 /* werror(W_TOOMANY_SPILS,"data space", */
3212 /* _G.dataExtend,currFunc->name,""); */
3216 if (options.dump_rassgn) {
3217 dumpEbbsToFileExt (DUMP_RASSGN, ebbi);
3218 dumpLiveRanges (DUMP_LRANGE, liveRanges);
3221 /* after that create the register mask
3222 for each of the instruction */
3223 createRegMask (ebbs, count);
3225 /* now get back the chain */
3226 ic = iCodeLabelOptimize (iCodeFromeBBlock (ebbs, count));
3228 ic = joinPushes (ic);
3230 /* redo that offsets for stacked automatic variables */
3231 redoStackOffsets ();
3235 /* free up any stackSpil locations allocated */
3236 applyToSet (_G.stackSpil, deallocStackSpil);
3238 setToNull ((void *) &_G.stackSpil);
3239 setToNull ((void *) &_G.spiltSet);
3240 /* mark all registers as free */