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->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, ("tryAllocRegPair: succeded for sym %p\n", sym));
1046 D (D_ALLOC, ("tryAllocRegPair: 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 /* if it does not need or is spilt
1136 or is already assigned to registers
1137 or will not live beyond this instructions */
1140 bitVectBitValue (_G.regAssigned, sym->key) ||
1141 sym->liveTo <= ic->seq)
1143 D (D_ALLOC, ("serialRegAssign: wont live long enough.\n"));
1147 /* if some liverange has been spilt at the block level
1148 and this one live beyond this block then spil this
1150 if (_G.blockSpil && sym->liveTo > ebbs[i]->lSeq)
1152 D (D_ALLOC, ("serialRegAssign: \"spilling to be safe.\"\n"));
1156 /* if trying to allocate this will cause
1157 a spill and there is nothing to spill
1158 or this one is rematerializable then
1160 willCS = willCauseSpill (sym->nRegs, sym->regType);
1161 spillable = computeSpillable (ic);
1163 (willCS && bitVectIsZero (spillable)))
1166 D (D_ALLOC, ("serialRegAssign: \"remat spill\"\n"));
1172 /* If the live range preceeds the point of definition
1173 then ideally we must take into account registers that
1174 have been allocated after sym->liveFrom but freed
1175 before ic->seq. This is complicated, so spill this
1176 symbol instead and let fillGaps handle the allocation. */
1177 if (sym->liveFrom < ic->seq)
1183 /* if it has a spillocation & is used less than
1184 all other live ranges then spill this */
1186 if (sym->usl.spillLoc) {
1187 symbol *leastUsed = leastUsedLR (liveRangesWith (spillable,
1188 allLRs, ebbs[i], ic));
1189 if (leastUsed && leastUsed->used > sym->used) {
1194 /* if none of the liveRanges have a spillLocation then better
1195 to spill this one than anything else already assigned to registers */
1196 if (liveRangesWith(spillable,noSpilLoc,ebbs[i],ic)) {
1197 /* if this is local to this block then we might find a block spil */
1198 if (!(sym->liveFrom >= ebbs[i]->fSeq && sym->liveTo <= ebbs[i]->lSeq)) {
1206 /* else we assign registers to it */
1207 _G.regAssigned = bitVectSetBit (_G.regAssigned, sym->key);
1208 _G.totRegAssigned = bitVectSetBit (_G.totRegAssigned, sym->key);
1210 /* Special case: Try to fit into a reg pair if
1212 D (D_ALLOC, ("serialRegAssign: actually allocing regs!\n"));
1213 if ((sym->nRegs == 2) && tryAllocatingRegPair (sym))
1218 for (j = 0; j < sym->nRegs; j++)
1220 sym->regs[j] = getRegGpr (ic, ebbs[i], sym);
1222 /* if the allocation falied which means
1223 this was spilt then break */
1226 D (D_ALLOC, ("Couldnt alloc (spill)\n"))
1231 /* if it shares registers with operands make sure
1232 that they are in the same position */
1233 if (IC_LEFT (ic) && IS_SYMOP (IC_LEFT (ic)) &&
1234 OP_SYMBOL (IC_LEFT (ic))->nRegs && ic->op != '=')
1235 positionRegs (OP_SYMBOL (IC_RESULT (ic)),
1236 OP_SYMBOL (IC_LEFT (ic)));
1237 /* do the same for the right operand */
1238 if (IC_RIGHT (ic) && IS_SYMOP (IC_RIGHT (ic)) &&
1239 OP_SYMBOL (IC_RIGHT (ic))->nRegs)
1240 positionRegs (OP_SYMBOL (IC_RESULT (ic)),
1241 OP_SYMBOL (IC_RIGHT (ic)));
1247 /* Check for and fix any problems with uninitialized operands */
1248 for (i = 0; i < count; i++)
1252 if (ebbs[i]->noPath &&
1253 (ebbs[i]->entryLabel != entryLabel &&
1254 ebbs[i]->entryLabel != returnLabel))
1257 for (ic = ebbs[i]->sch; ic; ic = ic->next)
1264 verifyRegsAssigned (IC_COND (ic), ic);
1268 if (ic->op == JUMPTABLE)
1270 verifyRegsAssigned (IC_JTCOND (ic), ic);
1274 verifyRegsAssigned (IC_RESULT (ic), ic);
1275 verifyRegsAssigned (IC_LEFT (ic), ic);
1276 verifyRegsAssigned (IC_RIGHT (ic), ic);
1282 /*-----------------------------------------------------------------*/
1283 /* fillGaps - Try to fill in the Gaps left by Pass1 */
1284 /*-----------------------------------------------------------------*/
1285 static void fillGaps()
1290 if (getenv("DISABLE_FILL_GAPS")) return;
1292 /* look for livernages that was spilt by the allocator */
1293 for (sym = hTabFirstItem(liveRanges,&key) ; sym ;
1294 sym = hTabNextItem(liveRanges,&key)) {
1299 if (!sym->spillA || !sym->clashes || sym->remat) continue ;
1301 /* find the liveRanges this one clashes with, that are
1302 still assigned to registers & mark the registers as used*/
1303 for ( i = 0 ; i < sym->clashes->size ; i ++) {
1307 if (bitVectBitValue(sym->clashes,i) == 0 || /* those that clash with this */
1308 bitVectBitValue(_G.totRegAssigned,i) == 0) /* and are still assigned to registers */
1311 clr = hTabItemWithKey(liveRanges,i);
1314 /* mark these registers as used */
1315 for (k = 0 ; k < clr->nRegs ; k++ )
1316 useReg(clr->regs[k]);
1319 if (willCauseSpill(sym->nRegs,sym->regType)) {
1320 /* NOPE :( clear all registers & and continue */
1325 /* THERE IS HOPE !!!! */
1326 for (i=0; i < sym->nRegs ; i++ ) {
1327 sym->regs[i] = getRegGprNoSpil ();
1330 /* for all its definitions check if the registers
1331 allocated needs positioning NOTE: we can position
1332 only ONCE if more than One positioning required
1335 for (i = 0 ; i < sym->defs->size ; i++ ) {
1336 if (bitVectBitValue(sym->defs,i)) {
1338 if (!(ic = hTabItemWithKey(iCodehTab,i))) continue ;
1339 if (SKIP_IC(ic)) continue;
1340 assert(isSymbolEqual(sym,OP_SYMBOL(IC_RESULT(ic)))); /* just making sure */
1341 /* if left is assigned to registers */
1342 if (IS_SYMOP(IC_LEFT(ic)) &&
1343 bitVectBitValue(_G.totRegAssigned,OP_SYMBOL(IC_LEFT(ic))->key)) {
1344 pdone += positionRegs(sym,OP_SYMBOL(IC_LEFT(ic)));
1346 if (IS_SYMOP(IC_RIGHT(ic)) &&
1347 bitVectBitValue(_G.totRegAssigned,OP_SYMBOL(IC_RIGHT(ic))->key)) {
1348 pdone += positionRegs(sym,OP_SYMBOL(IC_RIGHT(ic)));
1350 if (pdone > 1) break;
1353 for (i = 0 ; i < sym->uses->size ; i++ ) {
1354 if (bitVectBitValue(sym->uses,i)) {
1356 if (!(ic = hTabItemWithKey(iCodehTab,i))) continue ;
1357 if (SKIP_IC(ic)) continue;
1358 if (!IS_ASSIGN_ICODE(ic)) continue ;
1360 /* if result is assigned to registers */
1361 if (IS_SYMOP(IC_RESULT(ic)) &&
1362 bitVectBitValue(_G.totRegAssigned,OP_SYMBOL(IC_RESULT(ic))->key)) {
1363 pdone += positionRegs(sym,OP_SYMBOL(IC_RESULT(ic)));
1365 if (pdone > 1) break;
1368 /* had to position more than once GIVE UP */
1370 /* UNDO all the changes we made to try this */
1372 for (i=0; i < sym->nRegs ; i++ ) {
1373 sym->regs[i] = NULL;
1376 D(D_FILL_GAPS,("Fill Gap gave up due to positioning for %s in function %s\n",sym->name, currFunc ? currFunc->name : "UNKNOWN"));
1379 D(D_FILL_GAPS,("FILLED GAP for %s in function %s\n",sym->name, currFunc ? currFunc->name : "UNKNOWN"));
1380 _G.totRegAssigned = bitVectSetBit(_G.totRegAssigned,sym->key);
1381 sym->isspilt = sym->spillA = 0 ;
1382 sym->usl.spillLoc->allocreq--;
1387 /*-----------------------------------------------------------------*/
1388 /* rUmaskForOp :- returns register mask for an operand */
1389 /*-----------------------------------------------------------------*/
1391 rUmaskForOp (operand * op)
1397 /* only temporaries are assigned registers */
1401 sym = OP_SYMBOL (op);
1403 /* if spilt or no registers assigned to it
1405 if (sym->isspilt || !sym->nRegs)
1408 rumask = newBitVect (_G.nRegs);
1410 for (j = 0; j < sym->nRegs; j++)
1412 rumask = bitVectSetBit (rumask, sym->regs[j]->rIdx);
1419 z80_rUmaskForOp (operand * op)
1421 return rUmaskForOp (op);
1424 /** Returns bit vector of registers used in iCode.
1427 regsUsedIniCode (iCode * ic)
1429 bitVect *rmask = newBitVect (_G.nRegs);
1431 /* do the special cases first */
1434 rmask = bitVectUnion (rmask,
1435 rUmaskForOp (IC_COND (ic)));
1439 /* for the jumptable */
1440 if (ic->op == JUMPTABLE)
1442 rmask = bitVectUnion (rmask,
1443 rUmaskForOp (IC_JTCOND (ic)));
1448 /* of all other cases */
1450 rmask = bitVectUnion (rmask,
1451 rUmaskForOp (IC_LEFT (ic)));
1455 rmask = bitVectUnion (rmask,
1456 rUmaskForOp (IC_RIGHT (ic)));
1459 rmask = bitVectUnion (rmask,
1460 rUmaskForOp (IC_RESULT (ic)));
1466 /** For each instruction will determine the regsUsed.
1469 createRegMask (eBBlock ** ebbs, int count)
1473 /* for all blocks */
1474 for (i = 0; i < count; i++)
1478 if (ebbs[i]->noPath &&
1479 (ebbs[i]->entryLabel != entryLabel &&
1480 ebbs[i]->entryLabel != returnLabel))
1483 /* for all instructions */
1484 for (ic = ebbs[i]->sch; ic; ic = ic->next)
1489 if (SKIP_IC2 (ic) || !ic->rlive)
1492 /* first mark the registers used in this
1494 ic->rUsed = regsUsedIniCode (ic);
1495 _G.funcrUsed = bitVectUnion (_G.funcrUsed, ic->rUsed);
1497 /* now create the register mask for those
1498 registers that are in use : this is a
1499 super set of ic->rUsed */
1500 ic->rMask = newBitVect (_G.nRegs + 1);
1502 /* for all live Ranges alive at this point */
1503 for (j = 1; j < ic->rlive->size; j++)
1508 /* if not alive then continue */
1509 if (!bitVectBitValue (ic->rlive, j))
1512 /* find the live range we are interested in */
1513 if (!(sym = hTabItemWithKey (liveRanges, j)))
1515 werror (E_INTERNAL_ERROR, __FILE__, __LINE__,
1516 "createRegMask cannot find live range");
1520 /* if no register assigned to it */
1521 if (!sym->nRegs || sym->isspilt)
1524 /* for all the registers allocated to it */
1525 for (k = 0; k < sym->nRegs; k++)
1528 bitVectSetBit (ic->rMask, sym->regs[k]->rIdx);
1534 /** Returns the rematerialized string for a remat var.
1537 rematStr (symbol * sym)
1540 iCode *ic = sym->rematiCode;
1545 /* if plus or minus print the right hand side */
1546 if (ic->op == '+' || ic->op == '-')
1548 sprintf (s, "0x%04x %c ", (int) operandLitValue (IC_RIGHT (ic)),
1551 ic = OP_SYMBOL (IC_LEFT (ic))->rematiCode;
1554 /* we reached the end */
1555 sprintf (s, "%s", OP_SYMBOL (IC_LEFT (ic))->rname);
1562 /*-----------------------------------------------------------------*/
1563 /* regTypeNum - computes the type & number of registers required */
1564 /*-----------------------------------------------------------------*/
1571 /* for each live range do */
1572 for (sym = hTabFirstItem (liveRanges, &k); sym;
1573 sym = hTabNextItem (liveRanges, &k))
1576 /* if used zero times then no registers needed */
1577 if ((sym->liveTo - sym->liveFrom) == 0)
1580 D (D_ALLOC, ("regTypeNum: loop on sym %p\n", sym));
1582 /* if the live range is a temporary */
1586 /* if the type is marked as a conditional */
1587 if (sym->regType == REG_CND)
1590 /* if used in return only then we don't
1592 if (sym->ruonly || sym->accuse)
1594 if (IS_AGGREGATE (sym->type) || sym->isptr)
1595 sym->type = aggrToPtr (sym->type, FALSE);
1599 /* if not then we require registers */
1600 D (D_ALLOC, ("regTypeNum: isagg %u nRegs %u type %p\n", IS_AGGREGATE (sym->type) || sym->isptr, sym->nRegs, sym->type));
1601 sym->nRegs = ((IS_AGGREGATE (sym->type) || sym->isptr) ?
1602 getSize (sym->type = aggrToPtr (sym->type, FALSE)) :
1603 getSize (sym->type));
1604 D (D_ALLOC, ("regTypeNum: setting nRegs of %s (%p) to %u\n", sym->name, sym, sym->nRegs));
1606 D (D_ALLOC, ("regTypeNum: setup to assign regs sym %p\n", sym));
1610 fprintf (stderr, "allocated more than 4 or 0 registers for type ");
1611 printTypeChain (sym->type, stderr);
1612 fprintf (stderr, "\n");
1615 /* determine the type of register required */
1616 /* Always general purpose */
1617 sym->regType = REG_GPR;
1622 /* for the first run we don't provide */
1623 /* registers for true symbols we will */
1624 /* see how things go */
1625 D (D_ALLOC, ("regTypeNum: #2 setting num of %p to 0\n", sym));
1632 /** Mark all registers as free.
1639 D (D_ALLOC, ("freeAllRegs: running.\n"));
1641 for (i = 0; i < _G.nRegs; i++)
1642 regsZ80[i].isFree = 1;
1645 /*-----------------------------------------------------------------*/
1646 /* deallocStackSpil - this will set the stack pointer back */
1647 /*-----------------------------------------------------------------*/
1648 DEFSETFUNC (deallocStackSpil)
1656 /** Register reduction for assignment.
1659 packRegsForAssign (iCode * ic, eBBlock * ebp)
1663 D (D_ALLOC, ("packRegsForAssign: running on ic %p\n", ic));
1665 if (!IS_ITEMP (IC_RIGHT (ic)) ||
1666 OP_SYMBOL (IC_RIGHT (ic))->isind ||
1667 OP_LIVETO (IC_RIGHT (ic)) > ic->seq)
1672 /* find the definition of iTempNN scanning backwards if we find a
1673 a use of the true symbol in before we find the definition then
1675 for (dic = ic->prev; dic; dic = dic->prev)
1677 /* PENDING: Don't pack across function calls. */
1678 if (dic->op == CALL || dic->op == PCALL)
1689 if (IS_SYMOP (IC_COND (dic)) &&
1690 (IC_COND (dic)->key == IC_RESULT (ic)->key ||
1691 IC_COND (dic)->key == IC_RIGHT (ic)->key))
1699 if (IS_TRUE_SYMOP (IC_RESULT (dic)) &&
1700 IS_OP_VOLATILE (IC_RESULT (dic)))
1706 if (IS_SYMOP (IC_RESULT (dic)) &&
1707 IC_RESULT (dic)->key == IC_RIGHT (ic)->key)
1709 if (POINTER_SET (dic))
1715 if (IS_SYMOP (IC_RIGHT (dic)) &&
1716 (IC_RIGHT (dic)->key == IC_RESULT (ic)->key ||
1717 IC_RIGHT (dic)->key == IC_RIGHT (ic)->key))
1723 if (IS_SYMOP (IC_LEFT (dic)) &&
1724 (IC_LEFT (dic)->key == IC_RESULT (ic)->key ||
1725 IC_LEFT (dic)->key == IC_RIGHT (ic)->key))
1731 if (IS_SYMOP (IC_RESULT (dic)) &&
1732 IC_RESULT (dic)->key == IC_RESULT (ic)->key)
1742 return 0; /* did not find */
1744 /* if the result is on stack or iaccess then it must be
1745 the same atleast one of the operands */
1746 if (OP_SYMBOL (IC_RESULT (ic))->onStack ||
1747 OP_SYMBOL (IC_RESULT (ic))->iaccess)
1749 /* the operation has only one symbol
1750 operator then we can pack */
1751 if ((IC_LEFT (dic) && !IS_SYMOP (IC_LEFT (dic))) ||
1752 (IC_RIGHT (dic) && !IS_SYMOP (IC_RIGHT (dic))))
1755 if (!((IC_LEFT (dic) &&
1756 IC_RESULT (ic)->key == IC_LEFT (dic)->key) ||
1758 IC_RESULT (ic)->key == IC_RIGHT (dic)->key)))
1762 /* found the definition */
1763 /* replace the result with the result of */
1764 /* this assignment and remove this assignment */
1765 bitVectUnSetBit(OP_SYMBOL(IC_RESULT(dic))->defs,dic->key);
1766 IC_RESULT (dic) = IC_RESULT (ic);
1768 if (IS_ITEMP (IC_RESULT (dic)) && OP_SYMBOL (IC_RESULT (dic))->liveFrom > dic->seq)
1770 OP_SYMBOL (IC_RESULT (dic))->liveFrom = dic->seq;
1772 /* delete from liverange table also
1773 delete from all the points inbetween and the new
1775 for (sic = dic; sic != ic; sic = sic->next)
1777 bitVectUnSetBit (sic->rlive, IC_RESULT (ic)->key);
1778 if (IS_ITEMP (IC_RESULT (dic)))
1779 bitVectSetBit (sic->rlive, IC_RESULT (dic)->key);
1782 remiCodeFromeBBlock (ebp, ic);
1783 // PENDING: Check vs mcs51
1784 bitVectUnSetBit(OP_SYMBOL(IC_RESULT(ic))->defs,ic->key);
1785 hTabDeleteItem (&iCodehTab, ic->key, ic, DELETE_ITEM, NULL);
1786 OP_DEFS(IC_RESULT (dic))=bitVectSetBit (OP_DEFS (IC_RESULT (dic)), dic->key);
1790 /** Scanning backwards looks for first assig found.
1793 findAssignToSym (operand * op, iCode * ic)
1797 for (dic = ic->prev; dic; dic = dic->prev)
1800 /* if definition by assignment */
1801 if (dic->op == '=' &&
1802 !POINTER_SET (dic) &&
1803 IC_RESULT (dic)->key == op->key)
1804 /* && IS_TRUE_SYMOP(IC_RIGHT(dic)) */
1807 /* we are interested only if defined in far space */
1808 /* or in stack space in case of + & - */
1810 /* if assigned to a non-symbol then return
1812 if (!IS_SYMOP (IC_RIGHT (dic)))
1815 /* if the symbol is in far space then
1817 if (isOperandInFarSpace (IC_RIGHT (dic)))
1820 /* for + & - operations make sure that
1821 if it is on the stack it is the same
1822 as one of the three operands */
1823 if ((ic->op == '+' || ic->op == '-') &&
1824 OP_SYMBOL (IC_RIGHT (dic))->onStack)
1827 if (IC_RESULT (ic)->key != IC_RIGHT (dic)->key &&
1828 IC_LEFT (ic)->key != IC_RIGHT (dic)->key &&
1829 IC_RIGHT (ic)->key != IC_RIGHT (dic)->key)
1837 /* if we find an usage then we cannot delete it */
1838 if (IC_LEFT (dic) && IC_LEFT (dic)->key == op->key)
1841 if (IC_RIGHT (dic) && IC_RIGHT (dic)->key == op->key)
1844 if (POINTER_SET (dic) && IC_RESULT (dic)->key == op->key)
1848 /* now make sure that the right side of dic
1849 is not defined between ic & dic */
1852 iCode *sic = dic->next;
1854 for (; sic != ic; sic = sic->next)
1855 if (IC_RESULT (sic) &&
1856 IC_RESULT (sic)->key == IC_RIGHT (dic)->key)
1865 #if !DISABLE_PACKREGSFORSUPPORT
1868 /*-----------------------------------------------------------------*/
1869 /* packRegsForSupport :- reduce some registers for support calls */
1870 /*-----------------------------------------------------------------*/
1872 packRegsForSupport (iCode * ic, eBBlock * ebp)
1875 /* for the left & right operand :- look to see if the
1876 left was assigned a true symbol in far space in that
1877 case replace them */
1878 D (D_ALLOC, ("packRegsForSupport: running on ic %p\n", ic));
1880 if (IS_ITEMP (IC_LEFT (ic)) &&
1881 OP_SYMBOL (IC_LEFT (ic))->liveTo <= ic->seq)
1883 iCode *dic = findAssignToSym (IC_LEFT (ic), ic);
1889 /* found it we need to remove it from the
1891 for (sic = dic; sic != ic; sic = sic->next)
1892 bitVectUnSetBit (sic->rlive, IC_LEFT (ic)->key);
1894 IC_LEFT (ic)->operand.symOperand =
1895 IC_RIGHT (dic)->operand.symOperand;
1896 IC_LEFT (ic)->key = IC_RIGHT (dic)->operand.symOperand->key;
1897 remiCodeFromeBBlock (ebp, dic);
1898 bitVectUnSetBit(OP_SYMBOL(IC_RESULT(dic))->defs,dic->key);
1899 hTabDeleteItem (&iCodehTab, dic->key, dic, DELETE_ITEM, NULL);
1900 // PENDING: Check vs mcs51
1904 /* do the same for the right operand */
1907 IS_ITEMP (IC_RIGHT (ic)) &&
1908 OP_SYMBOL (IC_RIGHT (ic))->liveTo <= ic->seq)
1910 iCode *dic = findAssignToSym (IC_RIGHT (ic), ic);
1916 /* found it we need to remove it from the block */
1917 for (sic = dic; sic != ic; sic = sic->next)
1918 bitVectUnSetBit (sic->rlive, IC_RIGHT (ic)->key);
1920 IC_RIGHT (ic)->operand.symOperand =
1921 IC_RIGHT (dic)->operand.symOperand;
1922 IC_RIGHT (ic)->key = IC_RIGHT (dic)->operand.symOperand->key;
1924 remiCodeFromeBBlock (ebp, dic);
1925 bitVectUnSetBit(OP_SYMBOL(IC_RESULT(dic))->defs,dic->key);
1926 hTabDeleteItem (&iCodehTab, dic->key, dic, DELETE_ITEM, NULL);
1927 // PENDING: vs mcs51
1935 #define IS_OP_RUONLY(x) (x && IS_SYMOP(x) && OP_SYMBOL(x)->ruonly)
1937 /** Will reduce some registers for single use.
1940 packRegsForOneuse (iCode * ic, operand * op, eBBlock * ebp)
1946 D (D_ALLOC, ("packRegsForOneUse: running on ic %p\n", ic));
1948 /* if returning a literal then do nothing */
1952 /* only upto 2 bytes since we cannot predict
1953 the usage of b, & acc */
1954 if (getSize (operandType (op)) > 2)
1957 if (ic->op != RETURN &&
1961 /* this routine will mark the a symbol as used in one
1962 instruction use only && if the defintion is local
1963 (ie. within the basic block) && has only one definition &&
1964 that definiion is either a return value from a
1965 function or does not contain any variables in
1967 uses = bitVectCopy (OP_USES (op));
1968 bitVectUnSetBit (uses, ic->key); /* take away this iCode */
1969 if (!bitVectIsZero (uses)) /* has other uses */
1972 /* if it has only one defintion */
1973 if (bitVectnBitsOn (OP_DEFS (op)) > 1)
1974 return NULL; /* has more than one definition */
1976 /* get the that definition */
1978 hTabItemWithKey (iCodehTab,
1979 bitVectFirstBit (OP_DEFS (op)))))
1982 /* found the definition now check if it is local */
1983 if (dic->seq < ebp->fSeq ||
1984 dic->seq > ebp->lSeq)
1985 return NULL; /* non-local */
1987 /* now check if it is the return from a function call */
1988 if (dic->op == CALL || dic->op == PCALL)
1990 if (ic->op != SEND && ic->op != RETURN &&
1991 !POINTER_SET(ic) && !POINTER_GET(ic))
1993 OP_SYMBOL (op)->ruonly = 1;
1999 /* otherwise check that the definition does
2000 not contain any symbols in far space */
2001 if (isOperandInFarSpace (IC_LEFT (dic)) ||
2002 isOperandInFarSpace (IC_RIGHT (dic)) ||
2003 IS_OP_RUONLY (IC_LEFT (ic)) ||
2004 IS_OP_RUONLY (IC_RIGHT (ic)))
2009 /* if pointer set then make sure the pointer is one byte */
2010 if (POINTER_SET (dic))
2013 if (POINTER_GET (dic))
2018 /* also make sure the intervenening instructions
2019 don't have any thing in far space */
2020 for (dic = dic->next; dic && dic != ic; dic = dic->next)
2022 /* if there is an intervening function call then no */
2023 if (dic->op == CALL || dic->op == PCALL)
2025 /* if pointer set then make sure the pointer
2027 if (POINTER_SET (dic))
2030 if (POINTER_GET (dic))
2033 /* if address of & the result is remat the okay */
2034 if (dic->op == ADDRESS_OF &&
2035 OP_SYMBOL (IC_RESULT (dic))->remat)
2038 /* if left or right or result is in far space */
2039 if (isOperandInFarSpace (IC_LEFT (dic)) ||
2040 isOperandInFarSpace (IC_RIGHT (dic)) ||
2041 isOperandInFarSpace (IC_RESULT (dic)) ||
2042 IS_OP_RUONLY (IC_LEFT (dic)) ||
2043 IS_OP_RUONLY (IC_RIGHT (dic)) ||
2044 IS_OP_RUONLY (IC_RESULT (dic)))
2050 OP_SYMBOL (op)->ruonly = 1;
2054 /*-----------------------------------------------------------------*/
2055 /* isBitwiseOptimizable - requirements of JEAN LOUIS VERN */
2056 /*-----------------------------------------------------------------*/
2058 isBitwiseOptimizable (iCode * ic)
2060 sym_link *rtype = getSpec (operandType (IC_RIGHT (ic)));
2062 /* bitwise operations are considered optimizable
2063 under the following conditions (Jean-Louis VERN)
2075 if (IS_LITERAL (rtype))
2081 Certian assignments involving pointers can be temporarly stored
2092 #if !DISABLE_PACKREGSFORACCUSE
2095 /** Pack registers for acc use.
2096 When the result of this operation is small and short lived it may
2097 be able to be stored in the accumelator.
2100 packRegsForAccUse (iCode * ic)
2104 /* if this is an aggregate, e.g. a one byte char array */
2105 if (IS_AGGREGATE(operandType(IC_RESULT(ic)))) {
2109 /* if + or - then it has to be one byte result */
2110 if ((ic->op == '+' || ic->op == '-')
2111 && getSize (operandType (IC_RESULT (ic))) > 1)
2114 /* if shift operation make sure right side is not a literal */
2115 if (ic->op == RIGHT_OP &&
2116 (isOperandLiteral (IC_RIGHT (ic)) ||
2117 getSize (operandType (IC_RESULT (ic))) > 1))
2120 if (ic->op == LEFT_OP &&
2121 (isOperandLiteral (IC_RIGHT (ic)) ||
2122 getSize (operandType (IC_RESULT (ic))) > 1))
2125 /* has only one definition */
2126 if (bitVectnBitsOn (OP_DEFS (IC_RESULT (ic))) > 1)
2129 /* has only one use */
2130 if (bitVectnBitsOn (OP_USES (IC_RESULT (ic))) > 1)
2133 /* and the usage immediately follows this iCode */
2134 if (!(uic = hTabItemWithKey (iCodehTab,
2135 bitVectFirstBit (OP_USES (IC_RESULT (ic))))))
2138 if (ic->next != uic)
2141 /* if it is a conditional branch then we definitely can */
2145 if (uic->op == JUMPTABLE)
2149 /* if the usage is not is an assignment or an
2150 arithmetic / bitwise / shift operation then not */
2151 if (POINTER_SET (uic) &&
2152 getSize (aggrToPtr (operandType (IC_RESULT (uic)), FALSE)) > 1)
2156 if (uic->op != '=' &&
2157 !IS_ARITHMETIC_OP (uic) &&
2158 !IS_BITWISE_OP (uic) &&
2159 uic->op != LEFT_OP &&
2160 uic->op != RIGHT_OP)
2163 /* if used in ^ operation then make sure right is not a
2165 if (uic->op == '^' && isOperandLiteral (IC_RIGHT (uic)))
2168 /* if shift operation make sure right side is not a literal */
2169 if (uic->op == RIGHT_OP &&
2170 (isOperandLiteral (IC_RIGHT (uic)) ||
2171 getSize (operandType (IC_RESULT (uic))) > 1))
2174 if (uic->op == LEFT_OP &&
2175 (isOperandLiteral (IC_RIGHT (uic)) ||
2176 getSize (operandType (IC_RESULT (uic))) > 1))
2180 /* make sure that the result of this icode is not on the
2181 stack, since acc is used to compute stack offset */
2182 if (IS_TRUE_SYMOP (IC_RESULT (uic)) &&
2183 OP_SYMBOL (IC_RESULT (uic))->onStack)
2188 /* if either one of them in far space then we cannot */
2189 if ((IS_TRUE_SYMOP (IC_LEFT (uic)) &&
2190 isOperandInFarSpace (IC_LEFT (uic))) ||
2191 (IS_TRUE_SYMOP (IC_RIGHT (uic)) &&
2192 isOperandInFarSpace (IC_RIGHT (uic))))
2196 /* if the usage has only one operand then we can */
2197 if (IC_LEFT (uic) == NULL ||
2198 IC_RIGHT (uic) == NULL)
2201 /* make sure this is on the left side if not
2202 a '+' since '+' is commutative */
2203 if (ic->op != '+' &&
2204 IC_LEFT (uic)->key != IC_RESULT (ic)->key)
2207 // See mcs51 ralloc for reasoning
2209 /* if one of them is a literal then we can */
2210 if ((IC_LEFT (uic) && IS_OP_LITERAL (IC_LEFT (uic))) ||
2211 (IC_RIGHT (uic) && IS_OP_LITERAL (IC_RIGHT (uic))))
2218 /** This is confusing :) Guess for now */
2219 if (IC_LEFT (uic)->key == IC_RESULT (ic)->key &&
2220 (IS_ITEMP (IC_RIGHT (uic)) ||
2221 (IS_TRUE_SYMOP (IC_RIGHT (uic)))))
2224 if (IC_RIGHT (uic)->key == IC_RESULT (ic)->key &&
2225 (IS_ITEMP (IC_LEFT (uic)) ||
2226 (IS_TRUE_SYMOP (IC_LEFT (uic)))))
2230 OP_SYMBOL (IC_RESULT (ic))->accuse = ACCUSE_A;
2235 packRegsForHLUse (iCode * ic)
2239 /* PENDING: Could do IFX */
2245 /* has only one definition */
2246 if (bitVectnBitsOn (OP_DEFS (IC_RESULT (ic))) > 1)
2248 D (D_HLUSE, (" + Dropping as has more than one def\n"));
2252 /* has only one use */
2253 if (bitVectnBitsOn (OP_USES (IC_RESULT (ic))) > 1)
2255 D (D_HLUSE, (" + Dropping as has more than one use\n"));
2259 /* and the usage immediately follows this iCode */
2260 if (!(uic = hTabItemWithKey (iCodehTab,
2261 bitVectFirstBit (OP_USES (IC_RESULT (ic))))))
2263 D (D_HLUSE, (" + Dropping as usage isn't in this block\n"));
2267 if (ic->next != uic)
2269 D (D_HLUSE, (" + Dropping as usage doesn't follow this\n"));
2278 if (getSize (operandType (IC_RESULT (ic))) != 2 ||
2279 (IC_LEFT(uic) && getSize (operandType (IC_LEFT (uic))) != 2) ||
2280 (IC_RIGHT(uic) && getSize (operandType (IC_RIGHT (uic))) != 2))
2282 D (D_HLUSE, (" + Dropping as the result size is not 2\n"));
2288 if (ic->op == CAST && uic->op == IPUSH)
2290 if (ic->op == ADDRESS_OF && uic->op == IPUSH)
2292 if (ic->op == ADDRESS_OF && POINTER_GET (uic) && IS_ITEMP( IC_RESULT (uic)))
2294 if (ic->op == CALL && ic->parmBytes == 0 && (uic->op == '-' || uic->op == '+'))
2299 /* Case of assign a constant to offset in a static array. */
2300 if (ic->op == '+' && IS_VALOP (IC_RIGHT (ic)))
2302 if (uic->op == '=' && POINTER_SET (uic))
2306 else if (uic->op == IPUSH && getSize (operandType (IC_LEFT (uic))) == 2)
2313 D (D_HLUSE, (" + Dropping as it's a bad op\n"));
2316 OP_SYMBOL (IC_RESULT (ic))->accuse = ACCUSE_SCRATCH;
2320 packRegsForHLUse3 (iCode * lic, operand * op, eBBlock * ebp)
2325 bool isFirst = TRUE;
2327 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));
2331 if ( OP_SYMBOL(op)->accuse)
2336 if (OP_SYMBOL(op)->remat)
2341 /* Only defined once */
2342 if (bitVectnBitsOn (OP_DEFS (op)) > 1)
2345 if (getSize (operandType (op)) > 2)
2348 /* And this is the definition */
2349 if (bitVectFirstBit (OP_DEFS (op)) != lic->key)
2352 /* first check if any overlapping liverange has already been
2354 if (OP_SYMBOL(op)->clashes)
2356 for (i = 0 ; i < OP_SYMBOL(op)->clashes->size ; i++ )
2358 if (bitVectBitValue(OP_SYMBOL(op)->clashes,i))
2360 sym = hTabItemWithKey(liveRanges,i);
2361 if (sym->accuse == ACCUSE_SCRATCH)
2369 /* Nothing else that clashes with this is using the scratch
2370 register. Scan through all of the intermediate instructions and
2371 see if any of them could nuke HL.
2373 dic = ic = hTabFirstItemWK(iCodeSeqhTab,OP_SYMBOL(op)->liveFrom);
2375 for (; ic && ic->seq <= OP_SYMBOL(op)->liveTo;
2376 ic = hTabNextItem(iCodeSeqhTab, &key))
2380 D (D_PACK_HLUSE3, ("(On %p: op: %u next: %p)\n", ic, ic->op, ic->next));
2385 if (ic->op == ADDRESS_OF)
2387 if (POINTER_GET (ic))
2389 if (ic->op == '=' && !POINTER_SET(ic))
2393 if (IC_RESULT(ic) && IS_SYMOP(IC_RESULT(ic))
2394 && isOperandInDirSpace (IC_RESULT (ic)))
2397 if (IC_LEFT(ic) && IS_SYMOP(IC_LEFT(ic))
2398 && isOperandInDirSpace (IC_LEFT (ic)))
2401 if (IC_RIGHT(ic) && IS_SYMOP(IC_RIGHT(ic))
2402 && isOperandInDirSpace (IC_RIGHT (ic)))
2405 /* Handle the non left/right/result ones first */
2408 if (ic->op == JUMPTABLE)
2417 if (ic->op == IPUSH && isOperandEqual (op, IC_LEFT (ic)))
2420 if (ic->op == SEND && isOperandEqual (op, IC_LEFT (ic)))
2423 if (ic->op == CALL && isOperandEqual (op, IC_RESULT (ic)))
2426 if (ic->op == LEFT_OP && isOperandLiteral (IC_RIGHT (ic)))
2429 if ((ic->op == '=' && !POINTER_SET(ic)) ||
2430 ic->op == UNARYMINUS ||
2439 if (ic->op == '*' && isOperandEqual (op, IC_LEFT (ic)))
2442 if (POINTER_SET (ic) && isOperandEqual (op, IC_RESULT (ic)))
2445 if (POINTER_GET (ic) && isOperandEqual (op, IC_LEFT (ic)))
2448 if (IS_VALOP (IC_RIGHT (ic)) &&
2455 /* By default give up */
2459 D (D_PACK_HLUSE3, ("Succeeded!\n"))
2461 OP_SYMBOL (op)->accuse = ACCUSE_SCRATCH;
2466 packRegsForIYUse (iCode * lic, operand * op, eBBlock * ebp)
2473 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));
2477 if ( OP_SYMBOL(op)->accuse)
2482 if (OP_SYMBOL(op)->remat)
2487 /* Only defined once */
2488 if (bitVectnBitsOn (OP_DEFS (op)) > 1)
2491 /* And this is the definition */
2492 if (bitVectFirstBit (OP_DEFS (op)) != lic->key)
2495 /* first check if any overlapping liverange has already been
2497 if (OP_SYMBOL(op)->clashes)
2499 for (i = 0 ; i < OP_SYMBOL(op)->clashes->size ; i++ )
2501 if (bitVectBitValue(OP_SYMBOL(op)->clashes,i))
2503 sym = hTabItemWithKey(liveRanges,i);
2504 if (sym->accuse == ACCUSE_IY)
2512 /* Only a few instructions can load into IY */
2518 if (getSize (operandType (op)) != 2)
2520 D (D_ACCUSE2, (" + Dropping as operation has size is too big\n"));
2524 /* Nothing else that clashes with this is using the scratch
2525 register. Scan through all of the intermediate instructions and
2526 see if any of them could nuke HL.
2528 dic = ic = hTabFirstItemWK(iCodeSeqhTab,OP_SYMBOL(op)->liveFrom);
2531 for (; ic && ic->seq <= OP_SYMBOL(op)->liveTo;
2532 ic = hTabNextItem(iCodeSeqhTab,&key))
2537 if (ic->op == PCALL ||
2546 /* Be pessamistic. */
2550 D (D_PACK_IY, (" op: %u uses %u result: %d left: %d right: %d\n", ic->op, bitVectBitValue(uses, ic->key),
2551 IC_RESULT(ic) && IS_SYMOP(IC_RESULT(ic)) ? isOperandInDirSpace(IC_RESULT(ic)) : -1,
2552 IC_LEFT(ic) && IS_SYMOP(IC_LEFT(ic)) ? isOperandInDirSpace(IC_LEFT(ic)) : -1,
2553 IC_RIGHT(ic) && IS_SYMOP(IC_RIGHT(ic)) ? isOperandInDirSpace(IC_RIGHT(ic)) : -1
2556 if (IC_RESULT(ic) && IS_SYMOP(IC_RESULT(ic)) &&
2557 isOperandInDirSpace(IC_RESULT(ic)))
2560 if (IC_RIGHT(ic) && IS_SYMOP(IC_RIGHT(ic)) &&
2561 isOperandInDirSpace(IC_RIGHT(ic)))
2564 if (IC_LEFT(ic) && IS_SYMOP(IC_LEFT(ic)) &&
2565 isOperandInDirSpace(IC_LEFT(ic)))
2568 /* Only certain rules will work against IY. Check if this iCode uses
2570 if (bitVectBitValue(uses, ic->key) != 0)
2572 if (ic->op == '=' &&
2573 isOperandEqual(IC_RESULT(ic), op))
2576 if (ic->op == GET_VALUE_AT_ADDRESS &&
2577 isOperandEqual(IC_LEFT(ic), op))
2580 if (isOperandEqual(IC_RESULT(ic), IC_LEFT(ic)) == FALSE)
2583 if (IC_RIGHT (ic) && IS_VALOP (IC_RIGHT (ic)))
2585 if (ic->op == '+' ||
2588 /* Only works if the constant is small */
2589 if (operandLitValue (IC_RIGHT (ic)) < 4)
2598 /* This iCode doesn't use the sym. See if this iCode preserves IY.
2603 /* By default give up */
2607 D (D_PACK_IY, ("Succeeded IY!\n"));
2609 OP_SYMBOL (op)->accuse = ACCUSE_IY;
2613 /** Returns TRUE if this operation can use acc and if it preserves the value.
2616 opPreservesA (iCode * uic)
2620 /* If we've gotten this far then the thing to compare must be
2621 small enough and must be in A.
2626 if (uic->op == JUMPTABLE)
2628 D (D_ACCUSE2, (" + Dropping as operation is a Jumptable\n"));
2632 /* A pointer assign preserves A if A is the left value. */
2633 if (uic->op == '=' && POINTER_SET (uic))
2638 /* if the usage has only one operand then we can */
2639 /* PENDING: check */
2640 if (IC_LEFT (uic) == NULL ||
2641 IC_RIGHT (uic) == NULL)
2643 D (D_ACCUSE2, (" + Dropping as operation has only one operand\n"));
2647 /* PENDING: check this rule */
2648 if (getSize (operandType (IC_RESULT (uic))) > 1)
2650 D (D_ACCUSE2, (" + Dropping as operation has size is too big\n"));
2655 /* Disabled all of the old rules as they weren't verified and have
2656 caused at least one problem.
2661 /** Returns true if this operand preserves the value of A.
2664 opIgnoresA (iCode * ic, iCode * uic)
2666 /* A increment of an iTemp by a constant is OK. */
2667 if ( uic->op == '+' &&
2668 IS_ITEMP (IC_LEFT (uic)) &&
2669 IS_ITEMP (IC_RESULT (uic)) &&
2670 IS_OP_LITERAL (IC_RIGHT (uic)))
2672 unsigned int icount = (unsigned int) floatFromVal (IC_RIGHT (uic)->operand.valOperand);
2674 /* Being an ITEMP means that we're already a symbol. */
2676 IC_RESULT (uic)->operand.symOperand->key == IC_LEFT (uic)->operand.symOperand->key
2682 else if (uic->op == '=' && !POINTER_SET (uic))
2684 /* If they are equal and get optimised out then things are OK. */
2685 if (isOperandEqual (IC_RESULT (uic), IC_RIGHT (uic)))
2687 /* Straight assign is OK. */
2696 /* Some optimisation cases:
2708 ; genAssign (pointer)
2712 want to optimise down to:
2718 So genPointer get is OK
2719 genPlus where the right is constant, left is iTemp, and result is same as left
2720 genAssign (pointer) is OK
2731 ; genAssign (pointer)
2732 ; AOP_STK for _strcpy_to_1_1
2737 want to optimise down to:
2743 So genIfx where IC_COND has size of 1 and is a constant.
2746 /** Pack registers for acc use.
2747 When the result of this operation is small and short lived it may
2748 be able to be stored in the accumulator.
2750 Note that the 'A preserving' list is currently emperical :)
2753 packRegsForAccUse2 (iCode * ic)
2757 D (D_ACCUSE2, ("packRegsForAccUse2: running on ic %p line %u\n", ic, ic->lineno));
2761 /* Filter out all but those 'good' commands */
2763 !POINTER_GET (ic) &&
2766 !IS_BITWISE_OP (ic) &&
2772 ic->op != GETHBIT &&
2775 D (D_ACCUSE2, (" + Dropping as not a 'good' source command\n"));
2779 /* if + or - then it has to be one byte result.
2782 if ((ic->op == '+' || ic->op == '-')
2783 && getSize (operandType (IC_RESULT (ic))) > 1)
2785 D (D_ACCUSE2, (" + Dropping as it's a big + or -\n"));
2789 /* has only one definition */
2790 if (bitVectnBitsOn (OP_DEFS (IC_RESULT (ic))) > 1)
2792 D (D_ACCUSE2, (" + Dropping as it has more than one definition\n"));
2796 /* Right. We may be able to propagate it through if:
2797 For each in the chain of uses the intermediate is OK.
2799 /* Get next with 'uses result' bit on
2800 If this->next == next
2801 Validate use of next
2802 If OK, increase count
2804 /* and the usage immediately follows this iCode */
2805 if (!(uic = hTabItemWithKey (iCodehTab,
2806 bitVectFirstBit (OP_USES (IC_RESULT (ic))))))
2808 D (D_ACCUSE2, (" + Dropping as usage does not follow first\n"));
2813 /* Create a copy of the OP_USES bit vect */
2814 bitVect *uses = bitVectCopy (OP_USES (IC_RESULT (ic)));
2816 iCode *scan = ic, *next;
2820 setBit = bitVectFirstBit (uses);
2821 next = hTabItemWithKey (iCodehTab, setBit);
2822 if (scan->next == next)
2824 D (D_ACCUSE2_VERBOSE, (" ! Is next in line\n"));
2826 bitVectUnSetBit (uses, setBit);
2827 /* Still contigous. */
2828 if (!opPreservesA (next))
2830 D (D_ACCUSE2, (" + Dropping as operation doesn't preserve A\n"));
2833 D (D_ACCUSE2_VERBOSE, (" ! Preserves A, so continue scanning\n"));
2836 else if (scan->next == NULL && bitVectnBitsOn (uses) == 1 && next != NULL)
2838 if (next->prev == NULL)
2840 if (!opPreservesA (next))
2842 D (D_ACCUSE2, (" + Dropping as operation doesn't preserve A #2\n"));
2845 bitVectUnSetBit (uses, setBit);
2850 D (D_ACCUSE2, (" + Dropping as last in list and next doesn't start a block\n"));
2854 else if (scan->next == NULL)
2856 D (D_ACCUSE2, (" + Dropping as hit the end of the list\n"));
2857 D (D_ACCUSE2, (" + Next in htab: %p\n", next));
2862 if (opIgnoresA (ic, scan->next))
2866 D (D_ACCUSE2_VERBOSE, (" ! Op ignores A, so continue scanning\n"));
2870 D (D_ACCUSE2, (" + Dropping as parts are not consecuitive and intermediate might use A\n"));
2875 while (!bitVectIsZero (uses));
2877 OP_SYMBOL (IC_RESULT (ic))->accuse = ACCUSE_A;
2882 /** Does some transformations to reduce register pressure.
2885 packRegisters (eBBlock * ebp)
2890 D (D_ALLOC, ("packRegisters: entered.\n"));
2892 while (1 && !DISABLE_PACK_ASSIGN)
2895 /* look for assignments of the form */
2896 /* iTempNN = TRueSym (someoperation) SomeOperand */
2898 /* TrueSym := iTempNN:1 */
2899 for (ic = ebp->sch; ic; ic = ic->next)
2901 /* find assignment of the form TrueSym := iTempNN:1 */
2902 if (ic->op == '=' && !POINTER_SET (ic))
2903 change += packRegsForAssign (ic, ebp);
2909 for (ic = ebp->sch; ic; ic = ic->next)
2911 /* Safe: address of a true sym is always constant. */
2912 /* if this is an itemp & result of a address of a true sym
2913 then mark this as rematerialisable */
2914 D (D_ALLOC, ("packRegisters: looping on ic %p\n", ic));
2916 if (ic->op == ADDRESS_OF &&
2917 IS_ITEMP (IC_RESULT (ic)) &&
2918 IS_TRUE_SYMOP (IC_LEFT (ic)) &&
2919 bitVectnBitsOn (OP_DEFS (IC_RESULT (ic))) == 1 &&
2920 !OP_SYMBOL (IC_LEFT (ic))->onStack)
2923 OP_SYMBOL (IC_RESULT (ic))->remat = 1;
2924 OP_SYMBOL (IC_RESULT (ic))->rematiCode = ic;
2925 OP_SYMBOL (IC_RESULT (ic))->usl.spillLoc = NULL;
2928 /* Safe: just propagates the remat flag */
2929 /* if straight assignment then carry remat flag if this is the
2931 if (ic->op == '=' &&
2932 !POINTER_SET (ic) &&
2933 IS_SYMOP (IC_RIGHT (ic)) &&
2934 OP_SYMBOL (IC_RIGHT (ic))->remat &&
2935 bitVectnBitsOn (OP_SYMBOL (IC_RESULT (ic))->defs) <= 1)
2938 OP_SYMBOL (IC_RESULT (ic))->remat =
2939 OP_SYMBOL (IC_RIGHT (ic))->remat;
2940 OP_SYMBOL (IC_RESULT (ic))->rematiCode =
2941 OP_SYMBOL (IC_RIGHT (ic))->rematiCode;
2944 /* if the condition of an if instruction is defined in the
2945 previous instruction then mark the itemp as a conditional */
2946 if ((IS_CONDITIONAL (ic) ||
2947 ((ic->op == BITWISEAND ||
2950 isBitwiseOptimizable (ic))) &&
2951 ic->next && ic->next->op == IFX &&
2952 bitVectnBitsOn (OP_USES(IC_RESULT(ic)))==1 &&
2953 isOperandEqual (IC_RESULT (ic), IC_COND (ic->next)) &&
2954 OP_SYMBOL (IC_RESULT (ic))->liveTo <= ic->next->seq)
2957 OP_SYMBOL (IC_RESULT (ic))->regType = REG_CND;
2962 /* reduce for support function calls */
2963 if (ic->supportRtn || ic->op == '+' || ic->op == '-')
2964 packRegsForSupport (ic, ebp);
2967 /* some cases the redundant moves can
2968 can be eliminated for return statements */
2969 if (ic->op == RETURN || ic->op == SEND)
2971 packRegsForOneuse (ic, IC_LEFT (ic), ebp);
2974 /* if pointer set & left has a size more than
2975 one and right is not in far space */
2976 if (!DISABLE_PACK_ONE_USE &&
2978 /* MLH: no such thing.
2979 !isOperandInFarSpace(IC_RIGHT(ic)) && */
2980 !OP_SYMBOL (IC_RESULT (ic))->remat &&
2981 !IS_OP_RUONLY (IC_RIGHT (ic)) &&
2982 getSize (aggrToPtr (operandType (IC_RESULT (ic)), FALSE)) > 1)
2985 packRegsForOneuse (ic, IC_RESULT (ic), ebp);
2988 /* if pointer get */
2989 if (!DISABLE_PACK_ONE_USE &&
2991 IS_SYMOP (IC_LEFT (ic)) &&
2992 /* MLH: dont have far space
2993 !isOperandInFarSpace(IC_RESULT(ic))&& */
2994 !OP_SYMBOL (IC_LEFT (ic))->remat &&
2995 !IS_OP_RUONLY (IC_RESULT (ic)) &&
2996 getSize (aggrToPtr (operandType (IC_LEFT (ic)), FALSE)) > 1)
2999 packRegsForOneuse (ic, IC_LEFT (ic), ebp);
3002 /* pack registers for accumulator use, when the result of an
3003 arithmetic or bit wise operation has only one use, that use is
3004 immediately following the defintion and the using iCode has
3005 only one operand or has two operands but one is literal & the
3006 result of that operation is not on stack then we can leave the
3007 result of this operation in acc:b combination */
3009 if (!DISABLE_PACK_HL && IS_ITEMP (IC_RESULT (ic)))
3015 packRegsForHLUse (ic);
3019 packRegsForHLUse3 (ic, IC_RESULT (ic), ebp);
3023 if (!DISABLE_PACK_IY && IS_ITEMP (IC_RESULT (ic)) && IS_Z80)
3025 packRegsForIYUse (ic, IC_RESULT (ic), ebp);
3028 if (!DISABLE_PACK_ACC && IS_ITEMP (IC_RESULT (ic)) &&
3029 getSize (operandType (IC_RESULT (ic))) == 1)
3031 packRegsForAccUse2 (ic);
3036 /** Joins together two byte constant pushes into one word push.
3039 joinPushes (iCode *lic)
3043 for (ic = lic; ic; ic = ic->next)
3050 /* Anything past this? */
3055 /* This and the next pushes? */
3056 if (ic->op != IPUSH || uic->op != IPUSH)
3060 /* Both literals? */
3061 if ( !IS_OP_LITERAL (IC_LEFT (ic)) || !IS_OP_LITERAL (IC_LEFT (uic)))
3065 /* Both characters? */
3066 if ( getSize (operandType (IC_LEFT (ic))) != 1 || getSize (operandType (IC_LEFT (uic))) != 1)
3070 /* Pull out the values, make a new type, and create the new iCode for it.
3072 first = (int)operandLitValue ( IC_LEFT (ic));
3073 second = (int)operandLitValue ( IC_LEFT (uic));
3075 sprintf (buffer, "%uu", ((first << 8) | (second & 0xFF)) & 0xFFFFU);
3076 val = constVal (buffer);
3077 SPEC_NOUN (val->type) = V_INT;
3078 IC_LEFT (ic) = operandFromOperand (IC_LEFT (ic));
3079 IC_LEFT (ic)->operand.valOperand = val;
3081 /* Now remove the second one from the list. */
3082 ic->next = uic->next;
3085 /* Patch up the reverse link */
3086 uic->next->prev = ic;
3093 /*-----------------------------------------------------------------*/
3094 /* assignRegisters - assigns registers to each live range as need */
3095 /*-----------------------------------------------------------------*/
3097 z80_assignRegisters (eBBlock ** ebbs, int count)
3102 D (D_ALLOC, ("\n-> z80_assignRegisters: entered.\n"));
3104 setToNull ((void *) &_G.funcrUsed);
3105 setToNull ((void *) &_G.totRegAssigned);
3106 _G.stackExtend = _G.dataExtend = 0;
3110 /* DE is required for the code gen. */
3111 _G.nRegs = GBZ80_MAX_REGS;
3112 regsZ80 = _gbz80_regs;
3116 _G.nRegs = Z80_MAX_REGS;
3117 regsZ80 = _z80_regs;
3120 /* change assignments this will remove some
3121 live ranges reducing some register pressure */
3122 for (i = 0; i < count; i++)
3123 packRegisters (ebbs[i]);
3125 /* liveranges probably changed by register packing
3126 so we compute them again */
3127 recomputeLiveRanges (ebbs, count);
3129 if (options.dump_pack)
3130 dumpEbbsToFileExt (DUMP_PACK, ebbs, count);
3132 /* first determine for each live range the number of
3133 registers & the type of registers required for each */
3136 /* and serially allocate registers */
3137 serialRegAssign (ebbs, count);
3142 /* if stack was extended then tell the user */
3145 /* werror(W_TOOMANY_SPILS,"stack", */
3146 /* _G.stackExtend,currFunc->name,""); */
3152 /* werror(W_TOOMANY_SPILS,"data space", */
3153 /* _G.dataExtend,currFunc->name,""); */
3157 if (options.dump_rassgn) {
3158 dumpEbbsToFileExt (DUMP_RASSGN, ebbs, count);
3159 dumpLiveRanges (DUMP_LRANGE, liveRanges);
3162 /* after that create the register mask
3163 for each of the instruction */
3164 createRegMask (ebbs, count);
3166 /* now get back the chain */
3167 ic = iCodeLabelOptimize (iCodeFromeBBlock (ebbs, count));
3169 ic = joinPushes (ic);
3171 /* redo that offsets for stacked automatic variables */
3172 redoStackOffsets ();
3176 /* free up any stackSpil locations allocated */
3177 applyToSet (_G.stackSpil, deallocStackSpil);
3179 setToNull ((void *) &_G.stackSpil);
3180 setToNull ((void *) &_G.spiltSet);
3181 /* mark all registers as free */