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 /* 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"))
1238 /* if it shares registers with operands make sure
1239 that they are in the same position */
1240 if (IC_LEFT (ic) && IS_SYMOP (IC_LEFT (ic)) &&
1241 OP_SYMBOL (IC_LEFT (ic))->nRegs && ic->op != '=')
1242 positionRegs (OP_SYMBOL (IC_RESULT (ic)),
1243 OP_SYMBOL (IC_LEFT (ic)));
1244 /* do the same for the right operand */
1245 if (IC_RIGHT (ic) && IS_SYMOP (IC_RIGHT (ic)) &&
1246 OP_SYMBOL (IC_RIGHT (ic))->nRegs)
1247 positionRegs (OP_SYMBOL (IC_RESULT (ic)),
1248 OP_SYMBOL (IC_RIGHT (ic)));
1254 /* Check for and fix any problems with uninitialized operands */
1255 for (i = 0; i < count; i++)
1259 if (ebbs[i]->noPath &&
1260 (ebbs[i]->entryLabel != entryLabel &&
1261 ebbs[i]->entryLabel != returnLabel))
1264 for (ic = ebbs[i]->sch; ic; ic = ic->next)
1271 verifyRegsAssigned (IC_COND (ic), ic);
1275 if (ic->op == JUMPTABLE)
1277 verifyRegsAssigned (IC_JTCOND (ic), ic);
1281 verifyRegsAssigned (IC_RESULT (ic), ic);
1282 verifyRegsAssigned (IC_LEFT (ic), ic);
1283 verifyRegsAssigned (IC_RIGHT (ic), ic);
1289 /*-----------------------------------------------------------------*/
1290 /* fillGaps - Try to fill in the Gaps left by Pass1 */
1291 /*-----------------------------------------------------------------*/
1292 static void fillGaps()
1297 if (getenv("DISABLE_FILL_GAPS")) return;
1299 /* look for livernages that was spilt by the allocator */
1300 for (sym = hTabFirstItem(liveRanges,&key) ; sym ;
1301 sym = hTabNextItem(liveRanges,&key)) {
1306 if (!sym->spillA || !sym->clashes || sym->remat) continue ;
1308 /* find the liveRanges this one clashes with, that are
1309 still assigned to registers & mark the registers as used*/
1310 for ( i = 0 ; i < sym->clashes->size ; i ++) {
1314 if (bitVectBitValue(sym->clashes,i) == 0 || /* those that clash with this */
1315 bitVectBitValue(_G.totRegAssigned,i) == 0) /* and are still assigned to registers */
1318 clr = hTabItemWithKey(liveRanges,i);
1321 /* mark these registers as used */
1322 for (k = 0 ; k < clr->nRegs ; k++ )
1323 useReg(clr->regs[k]);
1326 if (willCauseSpill(sym->nRegs,sym->regType)) {
1327 /* NOPE :( clear all registers & and continue */
1332 /* THERE IS HOPE !!!! */
1333 for (i=0; i < sym->nRegs ; i++ ) {
1334 sym->regs[i] = getRegGprNoSpil ();
1337 /* for all its definitions check if the registers
1338 allocated needs positioning NOTE: we can position
1339 only ONCE if more than One positioning required
1342 for (i = 0 ; i < sym->defs->size ; i++ ) {
1343 if (bitVectBitValue(sym->defs,i)) {
1345 if (!(ic = hTabItemWithKey(iCodehTab,i))) continue ;
1346 if (SKIP_IC(ic)) continue;
1347 assert(isSymbolEqual(sym,OP_SYMBOL(IC_RESULT(ic)))); /* just making sure */
1348 /* if left is assigned to registers */
1349 if (IS_SYMOP(IC_LEFT(ic)) &&
1350 bitVectBitValue(_G.totRegAssigned,OP_SYMBOL(IC_LEFT(ic))->key)) {
1351 pdone += positionRegs(sym,OP_SYMBOL(IC_LEFT(ic)));
1353 if (IS_SYMOP(IC_RIGHT(ic)) &&
1354 bitVectBitValue(_G.totRegAssigned,OP_SYMBOL(IC_RIGHT(ic))->key)) {
1355 pdone += positionRegs(sym,OP_SYMBOL(IC_RIGHT(ic)));
1357 if (pdone > 1) break;
1360 for (i = 0 ; i < sym->uses->size ; i++ ) {
1361 if (bitVectBitValue(sym->uses,i)) {
1363 if (!(ic = hTabItemWithKey(iCodehTab,i))) continue ;
1364 if (SKIP_IC(ic)) continue;
1365 if (!IS_ASSIGN_ICODE(ic)) continue ;
1367 /* if result is assigned to registers */
1368 if (IS_SYMOP(IC_RESULT(ic)) &&
1369 bitVectBitValue(_G.totRegAssigned,OP_SYMBOL(IC_RESULT(ic))->key)) {
1370 pdone += positionRegs(sym,OP_SYMBOL(IC_RESULT(ic)));
1372 if (pdone > 1) break;
1375 /* had to position more than once GIVE UP */
1377 /* UNDO all the changes we made to try this */
1379 for (i=0; i < sym->nRegs ; i++ ) {
1380 sym->regs[i] = NULL;
1383 D(D_FILL_GAPS,("Fill Gap gave up due to positioning for %s in function %s\n",sym->name, currFunc ? currFunc->name : "UNKNOWN"));
1386 D(D_FILL_GAPS,("FILLED GAP for %s in function %s\n",sym->name, currFunc ? currFunc->name : "UNKNOWN"));
1387 _G.totRegAssigned = bitVectSetBit(_G.totRegAssigned,sym->key);
1388 sym->isspilt = sym->spillA = 0 ;
1389 sym->usl.spillLoc->allocreq--;
1394 /*-----------------------------------------------------------------*/
1395 /* rUmaskForOp :- returns register mask for an operand */
1396 /*-----------------------------------------------------------------*/
1398 rUmaskForOp (operand * op)
1404 /* only temporaries are assigned registers */
1408 sym = OP_SYMBOL (op);
1410 /* if spilt or no registers assigned to it
1412 if (sym->isspilt || !sym->nRegs)
1415 rumask = newBitVect (_G.nRegs);
1417 for (j = 0; j < sym->nRegs; j++)
1419 rumask = bitVectSetBit (rumask, sym->regs[j]->rIdx);
1426 z80_rUmaskForOp (operand * op)
1428 return rUmaskForOp (op);
1431 /** Returns bit vector of registers used in iCode.
1434 regsUsedIniCode (iCode * ic)
1436 bitVect *rmask = newBitVect (_G.nRegs);
1438 /* do the special cases first */
1441 rmask = bitVectUnion (rmask,
1442 rUmaskForOp (IC_COND (ic)));
1446 /* for the jumptable */
1447 if (ic->op == JUMPTABLE)
1449 rmask = bitVectUnion (rmask,
1450 rUmaskForOp (IC_JTCOND (ic)));
1455 /* of all other cases */
1457 rmask = bitVectUnion (rmask,
1458 rUmaskForOp (IC_LEFT (ic)));
1462 rmask = bitVectUnion (rmask,
1463 rUmaskForOp (IC_RIGHT (ic)));
1466 rmask = bitVectUnion (rmask,
1467 rUmaskForOp (IC_RESULT (ic)));
1473 /** For each instruction will determine the regsUsed.
1476 createRegMask (eBBlock ** ebbs, int count)
1480 /* for all blocks */
1481 for (i = 0; i < count; i++)
1485 if (ebbs[i]->noPath &&
1486 (ebbs[i]->entryLabel != entryLabel &&
1487 ebbs[i]->entryLabel != returnLabel))
1490 /* for all instructions */
1491 for (ic = ebbs[i]->sch; ic; ic = ic->next)
1496 if (SKIP_IC2 (ic) || !ic->rlive)
1499 /* first mark the registers used in this
1501 ic->rUsed = regsUsedIniCode (ic);
1502 _G.funcrUsed = bitVectUnion (_G.funcrUsed, ic->rUsed);
1504 /* now create the register mask for those
1505 registers that are in use : this is a
1506 super set of ic->rUsed */
1507 ic->rMask = newBitVect (_G.nRegs + 1);
1509 /* for all live Ranges alive at this point */
1510 for (j = 1; j < ic->rlive->size; j++)
1515 /* if not alive then continue */
1516 if (!bitVectBitValue (ic->rlive, j))
1519 /* find the live range we are interested in */
1520 if (!(sym = hTabItemWithKey (liveRanges, j)))
1522 werror (E_INTERNAL_ERROR, __FILE__, __LINE__,
1523 "createRegMask cannot find live range");
1527 /* if no register assigned to it */
1528 if (!sym->nRegs || sym->isspilt)
1531 /* for all the registers allocated to it */
1532 for (k = 0; k < sym->nRegs; k++)
1535 bitVectSetBit (ic->rMask, sym->regs[k]->rIdx);
1541 /** Returns the rematerialized string for a remat var.
1544 rematStr (symbol * sym)
1547 iCode *ic = sym->rematiCode;
1552 /* if plus or minus print the right hand side */
1553 if (ic->op == '+' || ic->op == '-')
1555 sprintf (s, "0x%04x %c ", (int) operandLitValue (IC_RIGHT (ic)),
1558 ic = OP_SYMBOL (IC_LEFT (ic))->rematiCode;
1561 /* we reached the end */
1562 sprintf (s, "%s", OP_SYMBOL (IC_LEFT (ic))->rname);
1569 /*-----------------------------------------------------------------*/
1570 /* regTypeNum - computes the type & number of registers required */
1571 /*-----------------------------------------------------------------*/
1578 /* for each live range do */
1579 for (sym = hTabFirstItem (liveRanges, &k); sym;
1580 sym = hTabNextItem (liveRanges, &k))
1583 /* if used zero times then no registers needed */
1584 if ((sym->liveTo - sym->liveFrom) == 0)
1587 D (D_ALLOC, ("regTypeNum: loop on sym %p\n", sym));
1589 /* if the live range is a temporary */
1593 /* if the type is marked as a conditional */
1594 if (sym->regType == REG_CND)
1597 /* if used in return only then we don't
1599 if (sym->ruonly || sym->accuse)
1601 if (IS_AGGREGATE (sym->type) || sym->isptr)
1602 sym->type = aggrToPtr (sym->type, FALSE);
1606 /* if not then we require registers */
1607 D (D_ALLOC, ("regTypeNum: isagg %u nRegs %u type %p\n", IS_AGGREGATE (sym->type) || sym->isptr, sym->nRegs, sym->type));
1608 sym->nRegs = ((IS_AGGREGATE (sym->type) || sym->isptr) ?
1609 getSize (sym->type = aggrToPtr (sym->type, FALSE)) :
1610 getSize (sym->type));
1611 D (D_ALLOC, ("regTypeNum: setting nRegs of %s (%p) to %u\n", sym->name, sym, sym->nRegs));
1613 D (D_ALLOC, ("regTypeNum: setup to assign regs sym %p\n", sym));
1617 fprintf (stderr, "allocated more than 4 or 0 registers for type ");
1618 printTypeChain (sym->type, stderr);
1619 fprintf (stderr, "\n");
1622 /* determine the type of register required */
1623 /* Always general purpose */
1624 sym->regType = REG_GPR;
1629 /* for the first run we don't provide */
1630 /* registers for true symbols we will */
1631 /* see how things go */
1632 D (D_ALLOC, ("regTypeNum: #2 setting num of %p to 0\n", sym));
1639 /** Mark all registers as free.
1646 D (D_ALLOC, ("freeAllRegs: running.\n"));
1648 for (i = 0; i < _G.nRegs; i++)
1649 regsZ80[i].isFree = 1;
1652 /*-----------------------------------------------------------------*/
1653 /* deallocStackSpil - this will set the stack pointer back */
1654 /*-----------------------------------------------------------------*/
1655 DEFSETFUNC (deallocStackSpil)
1663 /** Register reduction for assignment.
1666 packRegsForAssign (iCode * ic, eBBlock * ebp)
1670 D (D_ALLOC, ("packRegsForAssign: running on ic %p\n", ic));
1672 if (!IS_ITEMP (IC_RIGHT (ic)) ||
1673 OP_SYMBOL (IC_RIGHT (ic))->isind ||
1674 OP_LIVETO (IC_RIGHT (ic)) > ic->seq)
1679 /* find the definition of iTempNN scanning backwards if we find a
1680 a use of the true symbol in before we find the definition then
1682 for (dic = ic->prev; dic; dic = dic->prev)
1684 /* PENDING: Don't pack across function calls. */
1685 if (dic->op == CALL || dic->op == PCALL)
1696 if (IS_SYMOP (IC_COND (dic)) &&
1697 (IC_COND (dic)->key == IC_RESULT (ic)->key ||
1698 IC_COND (dic)->key == IC_RIGHT (ic)->key))
1706 if (IS_TRUE_SYMOP (IC_RESULT (dic)) &&
1707 IS_OP_VOLATILE (IC_RESULT (dic)))
1713 if (IS_SYMOP (IC_RESULT (dic)) &&
1714 IC_RESULT (dic)->key == IC_RIGHT (ic)->key)
1716 if (POINTER_SET (dic))
1722 if (IS_SYMOP (IC_RIGHT (dic)) &&
1723 (IC_RIGHT (dic)->key == IC_RESULT (ic)->key ||
1724 IC_RIGHT (dic)->key == IC_RIGHT (ic)->key))
1730 if (IS_SYMOP (IC_LEFT (dic)) &&
1731 (IC_LEFT (dic)->key == IC_RESULT (ic)->key ||
1732 IC_LEFT (dic)->key == IC_RIGHT (ic)->key))
1738 if (IS_SYMOP (IC_RESULT (dic)) &&
1739 IC_RESULT (dic)->key == IC_RESULT (ic)->key)
1749 return 0; /* did not find */
1751 /* if assignment then check that right is not a bit */
1752 if (ASSIGNMENT (ic) && !POINTER_SET (ic))
1754 sym_link *etype = operandType (IC_RESULT (dic));
1755 if (IS_BITFIELD (etype))
1757 /* if result is a bit too then it's ok */
1758 etype = operandType (IC_RESULT (ic));
1759 if (!IS_BITFIELD (etype))
1766 /* if the result is on stack or iaccess then it must be
1767 the same atleast one of the operands */
1768 if (OP_SYMBOL (IC_RESULT (ic))->onStack ||
1769 OP_SYMBOL (IC_RESULT (ic))->iaccess)
1771 /* the operation has only one symbol
1772 operator then we can pack */
1773 if ((IC_LEFT (dic) && !IS_SYMOP (IC_LEFT (dic))) ||
1774 (IC_RIGHT (dic) && !IS_SYMOP (IC_RIGHT (dic))))
1777 if (!((IC_LEFT (dic) &&
1778 IC_RESULT (ic)->key == IC_LEFT (dic)->key) ||
1780 IC_RESULT (ic)->key == IC_RIGHT (dic)->key)))
1784 /* found the definition */
1785 /* replace the result with the result of */
1786 /* this assignment and remove this assignment */
1787 bitVectUnSetBit(OP_SYMBOL(IC_RESULT(dic))->defs,dic->key);
1788 IC_RESULT (dic) = IC_RESULT (ic);
1790 if (IS_ITEMP (IC_RESULT (dic)) && OP_SYMBOL (IC_RESULT (dic))->liveFrom > dic->seq)
1792 OP_SYMBOL (IC_RESULT (dic))->liveFrom = dic->seq;
1794 /* delete from liverange table also
1795 delete from all the points inbetween and the new
1797 for (sic = dic; sic != ic; sic = sic->next)
1799 bitVectUnSetBit (sic->rlive, IC_RESULT (ic)->key);
1800 if (IS_ITEMP (IC_RESULT (dic)))
1801 bitVectSetBit (sic->rlive, IC_RESULT (dic)->key);
1804 remiCodeFromeBBlock (ebp, ic);
1805 // PENDING: Check vs mcs51
1806 bitVectUnSetBit(OP_SYMBOL(IC_RESULT(ic))->defs,ic->key);
1807 hTabDeleteItem (&iCodehTab, ic->key, ic, DELETE_ITEM, NULL);
1808 OP_DEFS(IC_RESULT (dic))=bitVectSetBit (OP_DEFS (IC_RESULT (dic)), dic->key);
1812 /** Scanning backwards looks for first assig found.
1815 findAssignToSym (operand * op, iCode * ic)
1819 for (dic = ic->prev; dic; dic = dic->prev)
1822 /* if definition by assignment */
1823 if (dic->op == '=' &&
1824 !POINTER_SET (dic) &&
1825 IC_RESULT (dic)->key == op->key)
1826 /* && IS_TRUE_SYMOP(IC_RIGHT(dic)) */
1829 /* we are interested only if defined in far space */
1830 /* or in stack space in case of + & - */
1832 /* if assigned to a non-symbol then return
1834 if (!IS_SYMOP (IC_RIGHT (dic)))
1837 /* if the symbol is in far space then
1839 if (isOperandInFarSpace (IC_RIGHT (dic)))
1842 /* for + & - operations make sure that
1843 if it is on the stack it is the same
1844 as one of the three operands */
1845 if ((ic->op == '+' || ic->op == '-') &&
1846 OP_SYMBOL (IC_RIGHT (dic))->onStack)
1849 if (IC_RESULT (ic)->key != IC_RIGHT (dic)->key &&
1850 IC_LEFT (ic)->key != IC_RIGHT (dic)->key &&
1851 IC_RIGHT (ic)->key != IC_RIGHT (dic)->key)
1859 /* if we find an usage then we cannot delete it */
1860 if (IC_LEFT (dic) && IC_LEFT (dic)->key == op->key)
1863 if (IC_RIGHT (dic) && IC_RIGHT (dic)->key == op->key)
1866 if (POINTER_SET (dic) && IC_RESULT (dic)->key == op->key)
1870 /* now make sure that the right side of dic
1871 is not defined between ic & dic */
1874 iCode *sic = dic->next;
1876 for (; sic != ic; sic = sic->next)
1877 if (IC_RESULT (sic) &&
1878 IC_RESULT (sic)->key == IC_RIGHT (dic)->key)
1887 #if !DISABLE_PACKREGSFORSUPPORT
1890 /*-----------------------------------------------------------------*/
1891 /* packRegsForSupport :- reduce some registers for support calls */
1892 /*-----------------------------------------------------------------*/
1894 packRegsForSupport (iCode * ic, eBBlock * ebp)
1897 /* for the left & right operand :- look to see if the
1898 left was assigned a true symbol in far space in that
1899 case replace them */
1900 D (D_ALLOC, ("packRegsForSupport: running on ic %p\n", ic));
1902 if (IS_ITEMP (IC_LEFT (ic)) &&
1903 OP_SYMBOL (IC_LEFT (ic))->liveTo <= ic->seq)
1905 iCode *dic = findAssignToSym (IC_LEFT (ic), ic);
1911 /* found it we need to remove it from the
1913 for (sic = dic; sic != ic; sic = sic->next)
1914 bitVectUnSetBit (sic->rlive, IC_LEFT (ic)->key);
1916 IC_LEFT (ic)->operand.symOperand =
1917 IC_RIGHT (dic)->operand.symOperand;
1918 IC_LEFT (ic)->key = IC_RIGHT (dic)->operand.symOperand->key;
1919 remiCodeFromeBBlock (ebp, dic);
1920 bitVectUnSetBit(OP_SYMBOL(IC_RESULT(dic))->defs,dic->key);
1921 hTabDeleteItem (&iCodehTab, dic->key, dic, DELETE_ITEM, NULL);
1922 // PENDING: Check vs mcs51
1926 /* do the same for the right operand */
1929 IS_ITEMP (IC_RIGHT (ic)) &&
1930 OP_SYMBOL (IC_RIGHT (ic))->liveTo <= ic->seq)
1932 iCode *dic = findAssignToSym (IC_RIGHT (ic), ic);
1938 /* found it we need to remove it from the block */
1939 for (sic = dic; sic != ic; sic = sic->next)
1940 bitVectUnSetBit (sic->rlive, IC_RIGHT (ic)->key);
1942 IC_RIGHT (ic)->operand.symOperand =
1943 IC_RIGHT (dic)->operand.symOperand;
1944 IC_RIGHT (ic)->key = IC_RIGHT (dic)->operand.symOperand->key;
1946 remiCodeFromeBBlock (ebp, dic);
1947 bitVectUnSetBit(OP_SYMBOL(IC_RESULT(dic))->defs,dic->key);
1948 hTabDeleteItem (&iCodehTab, dic->key, dic, DELETE_ITEM, NULL);
1949 // PENDING: vs mcs51
1957 #define IS_OP_RUONLY(x) (x && IS_SYMOP(x) && OP_SYMBOL(x)->ruonly)
1959 /** Will reduce some registers for single use.
1962 packRegsForOneuse (iCode * ic, operand * op, eBBlock * ebp)
1968 D (D_ALLOC, ("packRegsForOneUse: running on ic %p\n", ic));
1970 /* if returning a literal then do nothing */
1974 /* only upto 2 bytes since we cannot predict
1975 the usage of b, & acc */
1976 if (getSize (operandType (op)) > 2)
1979 if (ic->op != RETURN &&
1983 /* this routine will mark the a symbol as used in one
1984 instruction use only && if the defintion is local
1985 (ie. within the basic block) && has only one definition &&
1986 that definiion is either a return value from a
1987 function or does not contain any variables in
1989 uses = bitVectCopy (OP_USES (op));
1990 bitVectUnSetBit (uses, ic->key); /* take away this iCode */
1991 if (!bitVectIsZero (uses)) /* has other uses */
1994 /* if it has only one defintion */
1995 if (bitVectnBitsOn (OP_DEFS (op)) > 1)
1996 return NULL; /* has more than one definition */
1998 /* get the that definition */
2000 hTabItemWithKey (iCodehTab,
2001 bitVectFirstBit (OP_DEFS (op)))))
2004 /* found the definition now check if it is local */
2005 if (dic->seq < ebp->fSeq ||
2006 dic->seq > ebp->lSeq)
2007 return NULL; /* non-local */
2009 /* now check if it is the return from a function call */
2010 if (dic->op == CALL || dic->op == PCALL)
2012 if (ic->op != SEND && ic->op != RETURN &&
2013 !POINTER_SET(ic) && !POINTER_GET(ic))
2015 OP_SYMBOL (op)->ruonly = 1;
2021 /* otherwise check that the definition does
2022 not contain any symbols in far space */
2023 if (isOperandInFarSpace (IC_LEFT (dic)) ||
2024 isOperandInFarSpace (IC_RIGHT (dic)) ||
2025 IS_OP_RUONLY (IC_LEFT (ic)) ||
2026 IS_OP_RUONLY (IC_RIGHT (ic)))
2031 /* if pointer set then make sure the pointer is one byte */
2032 if (POINTER_SET (dic))
2035 if (POINTER_GET (dic))
2040 /* also make sure the intervenening instructions
2041 don't have any thing in far space */
2042 for (dic = dic->next; dic && dic != ic; dic = dic->next)
2044 /* if there is an intervening function call then no */
2045 if (dic->op == CALL || dic->op == PCALL)
2047 /* if pointer set then make sure the pointer
2049 if (POINTER_SET (dic))
2052 if (POINTER_GET (dic))
2055 /* if address of & the result is remat the okay */
2056 if (dic->op == ADDRESS_OF &&
2057 OP_SYMBOL (IC_RESULT (dic))->remat)
2060 /* if left or right or result is in far space */
2061 if (isOperandInFarSpace (IC_LEFT (dic)) ||
2062 isOperandInFarSpace (IC_RIGHT (dic)) ||
2063 isOperandInFarSpace (IC_RESULT (dic)) ||
2064 IS_OP_RUONLY (IC_LEFT (dic)) ||
2065 IS_OP_RUONLY (IC_RIGHT (dic)) ||
2066 IS_OP_RUONLY (IC_RESULT (dic)))
2072 OP_SYMBOL (op)->ruonly = 1;
2076 /*-----------------------------------------------------------------*/
2077 /* isBitwiseOptimizable - requirements of JEAN LOUIS VERN */
2078 /*-----------------------------------------------------------------*/
2080 isBitwiseOptimizable (iCode * ic)
2082 sym_link *rtype = getSpec (operandType (IC_RIGHT (ic)));
2084 /* bitwise operations are considered optimizable
2085 under the following conditions (Jean-Louis VERN)
2097 if (IS_LITERAL (rtype))
2103 Certian assignments involving pointers can be temporarly stored
2114 #if !DISABLE_PACKREGSFORACCUSE
2117 /** Pack registers for acc use.
2118 When the result of this operation is small and short lived it may
2119 be able to be stored in the accumelator.
2122 packRegsForAccUse (iCode * ic)
2126 /* if this is an aggregate, e.g. a one byte char array */
2127 if (IS_AGGREGATE(operandType(IC_RESULT(ic)))) {
2131 /* if + or - then it has to be one byte result */
2132 if ((ic->op == '+' || ic->op == '-')
2133 && getSize (operandType (IC_RESULT (ic))) > 1)
2136 /* if shift operation make sure right side is not a literal */
2137 if (ic->op == RIGHT_OP &&
2138 (isOperandLiteral (IC_RIGHT (ic)) ||
2139 getSize (operandType (IC_RESULT (ic))) > 1))
2142 if (ic->op == LEFT_OP &&
2143 (isOperandLiteral (IC_RIGHT (ic)) ||
2144 getSize (operandType (IC_RESULT (ic))) > 1))
2147 /* has only one definition */
2148 if (bitVectnBitsOn (OP_DEFS (IC_RESULT (ic))) > 1)
2151 /* has only one use */
2152 if (bitVectnBitsOn (OP_USES (IC_RESULT (ic))) > 1)
2155 /* and the usage immediately follows this iCode */
2156 if (!(uic = hTabItemWithKey (iCodehTab,
2157 bitVectFirstBit (OP_USES (IC_RESULT (ic))))))
2160 if (ic->next != uic)
2163 /* if it is a conditional branch then we definitely can */
2167 if (uic->op == JUMPTABLE)
2171 /* if the usage is not is an assignment or an
2172 arithmetic / bitwise / shift operation then not */
2173 if (POINTER_SET (uic) &&
2174 getSize (aggrToPtr (operandType (IC_RESULT (uic)), FALSE)) > 1)
2178 if (uic->op != '=' &&
2179 !IS_ARITHMETIC_OP (uic) &&
2180 !IS_BITWISE_OP (uic) &&
2181 uic->op != LEFT_OP &&
2182 uic->op != RIGHT_OP)
2185 /* if used in ^ operation then make sure right is not a
2187 if (uic->op == '^' && isOperandLiteral (IC_RIGHT (uic)))
2190 /* if shift operation make sure right side is not a literal */
2191 if (uic->op == RIGHT_OP &&
2192 (isOperandLiteral (IC_RIGHT (uic)) ||
2193 getSize (operandType (IC_RESULT (uic))) > 1))
2196 if (uic->op == LEFT_OP &&
2197 (isOperandLiteral (IC_RIGHT (uic)) ||
2198 getSize (operandType (IC_RESULT (uic))) > 1))
2202 /* make sure that the result of this icode is not on the
2203 stack, since acc is used to compute stack offset */
2204 if (IS_TRUE_SYMOP (IC_RESULT (uic)) &&
2205 OP_SYMBOL (IC_RESULT (uic))->onStack)
2210 /* if either one of them in far space then we cannot */
2211 if ((IS_TRUE_SYMOP (IC_LEFT (uic)) &&
2212 isOperandInFarSpace (IC_LEFT (uic))) ||
2213 (IS_TRUE_SYMOP (IC_RIGHT (uic)) &&
2214 isOperandInFarSpace (IC_RIGHT (uic))))
2218 /* if the usage has only one operand then we can */
2219 if (IC_LEFT (uic) == NULL ||
2220 IC_RIGHT (uic) == NULL)
2223 /* make sure this is on the left side if not
2224 a '+' since '+' is commutative */
2225 if (ic->op != '+' &&
2226 IC_LEFT (uic)->key != IC_RESULT (ic)->key)
2229 // See mcs51 ralloc for reasoning
2231 /* if one of them is a literal then we can */
2232 if ((IC_LEFT (uic) && IS_OP_LITERAL (IC_LEFT (uic))) ||
2233 (IC_RIGHT (uic) && IS_OP_LITERAL (IC_RIGHT (uic))))
2240 /** This is confusing :) Guess for now */
2241 if (IC_LEFT (uic)->key == IC_RESULT (ic)->key &&
2242 (IS_ITEMP (IC_RIGHT (uic)) ||
2243 (IS_TRUE_SYMOP (IC_RIGHT (uic)))))
2246 if (IC_RIGHT (uic)->key == IC_RESULT (ic)->key &&
2247 (IS_ITEMP (IC_LEFT (uic)) ||
2248 (IS_TRUE_SYMOP (IC_LEFT (uic)))))
2252 OP_SYMBOL (IC_RESULT (ic))->accuse = ACCUSE_A;
2257 packRegsForHLUse (iCode * ic)
2261 /* PENDING: Could do IFX */
2267 /* has only one definition */
2268 if (bitVectnBitsOn (OP_DEFS (IC_RESULT (ic))) > 1)
2270 D (D_HLUSE, (" + Dropping as has more than one def\n"));
2274 /* has only one use */
2275 if (bitVectnBitsOn (OP_USES (IC_RESULT (ic))) > 1)
2277 D (D_HLUSE, (" + Dropping as has more than one use\n"));
2281 /* and the usage immediately follows this iCode */
2282 if (!(uic = hTabItemWithKey (iCodehTab,
2283 bitVectFirstBit (OP_USES (IC_RESULT (ic))))))
2285 D (D_HLUSE, (" + Dropping as usage isn't in this block\n"));
2289 if (ic->next != uic)
2291 D (D_HLUSE, (" + Dropping as usage doesn't follow this\n"));
2300 if (getSize (operandType (IC_RESULT (ic))) != 2 ||
2301 (IC_LEFT(uic) && getSize (operandType (IC_LEFT (uic))) != 2) ||
2302 (IC_RIGHT(uic) && getSize (operandType (IC_RIGHT (uic))) != 2))
2304 D (D_HLUSE, (" + Dropping as the result size is not 2\n"));
2310 if (ic->op == CAST && uic->op == IPUSH)
2312 if (ic->op == ADDRESS_OF && uic->op == IPUSH)
2314 if (ic->op == ADDRESS_OF && POINTER_GET (uic) && IS_ITEMP( IC_RESULT (uic)))
2316 if (ic->op == CALL && ic->parmBytes == 0 && (uic->op == '-' || uic->op == '+'))
2321 /* Case of assign a constant to offset in a static array. */
2322 if (ic->op == '+' && IS_VALOP (IC_RIGHT (ic)))
2324 if (uic->op == '=' && POINTER_SET (uic))
2328 else if (uic->op == IPUSH && getSize (operandType (IC_LEFT (uic))) == 2)
2335 D (D_HLUSE, (" + Dropping as it's a bad op\n"));
2338 OP_SYMBOL (IC_RESULT (ic))->accuse = ACCUSE_SCRATCH;
2342 packRegsForHLUse3 (iCode * lic, operand * op, eBBlock * ebp)
2347 bool isFirst = TRUE;
2349 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));
2353 if ( OP_SYMBOL(op)->accuse)
2358 if (OP_SYMBOL(op)->remat)
2363 /* Only defined once */
2364 if (bitVectnBitsOn (OP_DEFS (op)) > 1)
2367 if (getSize (operandType (op)) > 2)
2370 /* And this is the definition */
2371 if (bitVectFirstBit (OP_DEFS (op)) != lic->key)
2374 /* first check if any overlapping liverange has already been
2376 if (OP_SYMBOL(op)->clashes)
2378 for (i = 0 ; i < OP_SYMBOL(op)->clashes->size ; i++ )
2380 if (bitVectBitValue(OP_SYMBOL(op)->clashes,i))
2382 sym = hTabItemWithKey(liveRanges,i);
2383 if (sym->accuse == ACCUSE_SCRATCH)
2391 /* Nothing else that clashes with this is using the scratch
2392 register. Scan through all of the intermediate instructions and
2393 see if any of them could nuke HL.
2395 dic = ic = hTabFirstItemWK(iCodeSeqhTab,OP_SYMBOL(op)->liveFrom);
2397 for (; ic && ic->seq <= OP_SYMBOL(op)->liveTo;
2398 ic = hTabNextItem(iCodeSeqhTab, &key))
2402 D (D_PACK_HLUSE3, ("(On %p: op: %u next: %p)\n", ic, ic->op, ic->next));
2407 if (ic->op == ADDRESS_OF)
2409 if (POINTER_GET (ic))
2411 if (ic->op == '=' && !POINTER_SET(ic))
2415 if (IC_RESULT(ic) && IS_SYMOP(IC_RESULT(ic))
2416 && isOperandInDirSpace (IC_RESULT (ic)))
2419 if (IC_LEFT(ic) && IS_SYMOP(IC_LEFT(ic))
2420 && isOperandInDirSpace (IC_LEFT (ic)))
2423 if (IC_RIGHT(ic) && IS_SYMOP(IC_RIGHT(ic))
2424 && isOperandInDirSpace (IC_RIGHT (ic)))
2427 /* Handle the non left/right/result ones first */
2430 if (ic->op == JUMPTABLE)
2439 if (ic->op == IPUSH && isOperandEqual (op, IC_LEFT (ic)))
2442 if (ic->op == SEND && isOperandEqual (op, IC_LEFT (ic)))
2445 if (ic->op == CALL && isOperandEqual (op, IC_RESULT (ic)))
2448 if (ic->op == LEFT_OP && isOperandLiteral (IC_RIGHT (ic)))
2451 if ((ic->op == '=' && !POINTER_SET(ic)) ||
2452 ic->op == UNARYMINUS ||
2461 if (ic->op == '*' && isOperandEqual (op, IC_LEFT (ic)))
2464 if (POINTER_SET (ic) && isOperandEqual (op, IC_RESULT (ic)))
2467 if (POINTER_GET (ic) && isOperandEqual (op, IC_LEFT (ic)))
2470 if (IS_VALOP (IC_RIGHT (ic)) &&
2477 /* By default give up */
2481 D (D_PACK_HLUSE3, ("Succeeded!\n"))
2483 OP_SYMBOL (op)->accuse = ACCUSE_SCRATCH;
2488 packRegsForIYUse (iCode * lic, operand * op, eBBlock * ebp)
2495 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));
2499 if ( OP_SYMBOL(op)->accuse)
2504 if (OP_SYMBOL(op)->remat)
2509 /* Only defined once */
2510 if (bitVectnBitsOn (OP_DEFS (op)) > 1)
2513 /* And this is the definition */
2514 if (bitVectFirstBit (OP_DEFS (op)) != lic->key)
2517 /* first check if any overlapping liverange has already been
2519 if (OP_SYMBOL(op)->clashes)
2521 for (i = 0 ; i < OP_SYMBOL(op)->clashes->size ; i++ )
2523 if (bitVectBitValue(OP_SYMBOL(op)->clashes,i))
2525 sym = hTabItemWithKey(liveRanges,i);
2526 if (sym->accuse == ACCUSE_IY)
2534 /* Only a few instructions can load into IY */
2540 if (getSize (operandType (op)) != 2)
2542 D (D_ACCUSE2, (" + Dropping as operation has size is too big\n"));
2546 /* Nothing else that clashes with this is using the scratch
2547 register. Scan through all of the intermediate instructions and
2548 see if any of them could nuke HL.
2550 dic = ic = hTabFirstItemWK(iCodeSeqhTab,OP_SYMBOL(op)->liveFrom);
2553 for (; ic && ic->seq <= OP_SYMBOL(op)->liveTo;
2554 ic = hTabNextItem(iCodeSeqhTab,&key))
2559 if (ic->op == PCALL ||
2568 /* Be pessamistic. */
2572 D (D_PACK_IY, (" op: %u uses %u result: %d left: %d right: %d\n", ic->op, bitVectBitValue(uses, ic->key),
2573 IC_RESULT(ic) && IS_SYMOP(IC_RESULT(ic)) ? isOperandInDirSpace(IC_RESULT(ic)) : -1,
2574 IC_LEFT(ic) && IS_SYMOP(IC_LEFT(ic)) ? isOperandInDirSpace(IC_LEFT(ic)) : -1,
2575 IC_RIGHT(ic) && IS_SYMOP(IC_RIGHT(ic)) ? isOperandInDirSpace(IC_RIGHT(ic)) : -1
2578 if (IC_RESULT(ic) && IS_SYMOP(IC_RESULT(ic)) &&
2579 isOperandInDirSpace(IC_RESULT(ic)))
2582 if (IC_RIGHT(ic) && IS_SYMOP(IC_RIGHT(ic)) &&
2583 isOperandInDirSpace(IC_RIGHT(ic)))
2586 if (IC_LEFT(ic) && IS_SYMOP(IC_LEFT(ic)) &&
2587 isOperandInDirSpace(IC_LEFT(ic)))
2590 /* Only certain rules will work against IY. Check if this iCode uses
2592 if (bitVectBitValue(uses, ic->key) != 0)
2594 if (ic->op == '=' &&
2595 isOperandEqual(IC_RESULT(ic), op))
2598 if (ic->op == GET_VALUE_AT_ADDRESS &&
2599 isOperandEqual(IC_LEFT(ic), op))
2602 if (isOperandEqual(IC_RESULT(ic), IC_LEFT(ic)) == FALSE)
2605 if (IC_RIGHT (ic) && IS_VALOP (IC_RIGHT (ic)))
2607 if (ic->op == '+' ||
2610 /* Only works if the constant is small */
2611 if (operandLitValue (IC_RIGHT (ic)) < 4)
2620 /* This iCode doesn't use the sym. See if this iCode preserves IY.
2625 /* By default give up */
2629 D (D_PACK_IY, ("Succeeded IY!\n"));
2631 OP_SYMBOL (op)->accuse = ACCUSE_IY;
2635 /** Returns TRUE if this operation can use acc and if it preserves the value.
2638 opPreservesA (iCode * uic)
2642 /* If we've gotten this far then the thing to compare must be
2643 small enough and must be in A.
2648 if (uic->op == JUMPTABLE)
2650 D (D_ACCUSE2, (" + Dropping as operation is a Jumptable\n"));
2654 /* A pointer assign preserves A if A is the left value. */
2655 if (uic->op == '=' && POINTER_SET (uic))
2660 /* if the usage has only one operand then we can */
2661 /* PENDING: check */
2662 if (IC_LEFT (uic) == NULL ||
2663 IC_RIGHT (uic) == NULL)
2665 D (D_ACCUSE2, (" + Dropping as operation has only one operand\n"));
2669 /* PENDING: check this rule */
2670 if (getSize (operandType (IC_RESULT (uic))) > 1)
2672 D (D_ACCUSE2, (" + Dropping as operation has size is too big\n"));
2677 /* Disabled all of the old rules as they weren't verified and have
2678 caused at least one problem.
2683 /** Returns true if this operand preserves the value of A.
2686 opIgnoresA (iCode * ic, iCode * uic)
2688 /* A increment of an iTemp by a constant is OK. */
2689 if ( uic->op == '+' &&
2690 IS_ITEMP (IC_LEFT (uic)) &&
2691 IS_ITEMP (IC_RESULT (uic)) &&
2692 IS_OP_LITERAL (IC_RIGHT (uic)))
2694 unsigned int icount = (unsigned int) floatFromVal (IC_RIGHT (uic)->operand.valOperand);
2696 /* Being an ITEMP means that we're already a symbol. */
2698 IC_RESULT (uic)->operand.symOperand->key == IC_LEFT (uic)->operand.symOperand->key
2704 else if (uic->op == '=' && !POINTER_SET (uic))
2706 /* If they are equal and get optimised out then things are OK. */
2707 if (isOperandEqual (IC_RESULT (uic), IC_RIGHT (uic)))
2709 /* Straight assign is OK. */
2718 /* Some optimisation cases:
2730 ; genAssign (pointer)
2734 want to optimise down to:
2740 So genPointer get is OK
2741 genPlus where the right is constant, left is iTemp, and result is same as left
2742 genAssign (pointer) is OK
2753 ; genAssign (pointer)
2754 ; AOP_STK for _strcpy_to_1_1
2759 want to optimise down to:
2765 So genIfx where IC_COND has size of 1 and is a constant.
2768 /** Pack registers for acc use.
2769 When the result of this operation is small and short lived it may
2770 be able to be stored in the accumulator.
2772 Note that the 'A preserving' list is currently emperical :)
2775 packRegsForAccUse2 (iCode * ic)
2779 D (D_ACCUSE2, ("packRegsForAccUse2: running on ic %p line %u\n", ic, ic->lineno));
2783 /* Filter out all but those 'good' commands */
2785 !POINTER_GET (ic) &&
2788 !IS_BITWISE_OP (ic) &&
2794 ic->op != GETHBIT &&
2797 D (D_ACCUSE2, (" + Dropping as not a 'good' source command\n"));
2801 /* if + or - then it has to be one byte result.
2804 if ((ic->op == '+' || ic->op == '-')
2805 && getSize (operandType (IC_RESULT (ic))) > 1)
2807 D (D_ACCUSE2, (" + Dropping as it's a big + or -\n"));
2811 /* has only one definition */
2812 if (bitVectnBitsOn (OP_DEFS (IC_RESULT (ic))) > 1)
2814 D (D_ACCUSE2, (" + Dropping as it has more than one definition\n"));
2818 /* Right. We may be able to propagate it through if:
2819 For each in the chain of uses the intermediate is OK.
2821 /* Get next with 'uses result' bit on
2822 If this->next == next
2823 Validate use of next
2824 If OK, increase count
2826 /* and the usage immediately follows this iCode */
2827 if (!(uic = hTabItemWithKey (iCodehTab,
2828 bitVectFirstBit (OP_USES (IC_RESULT (ic))))))
2830 D (D_ACCUSE2, (" + Dropping as usage does not follow first\n"));
2835 /* Create a copy of the OP_USES bit vect */
2836 bitVect *uses = bitVectCopy (OP_USES (IC_RESULT (ic)));
2838 iCode *scan = ic, *next;
2842 setBit = bitVectFirstBit (uses);
2843 next = hTabItemWithKey (iCodehTab, setBit);
2844 if (scan->next == next)
2846 D (D_ACCUSE2_VERBOSE, (" ! Is next in line\n"));
2848 bitVectUnSetBit (uses, setBit);
2849 /* Still contigous. */
2850 if (!opPreservesA (next))
2852 D (D_ACCUSE2, (" + Dropping as operation doesn't preserve A\n"));
2855 D (D_ACCUSE2_VERBOSE, (" ! Preserves A, so continue scanning\n"));
2858 else if (scan->next == NULL && bitVectnBitsOn (uses) == 1 && next != NULL)
2860 if (next->prev == NULL)
2862 if (!opPreservesA (next))
2864 D (D_ACCUSE2, (" + Dropping as operation doesn't preserve A #2\n"));
2867 bitVectUnSetBit (uses, setBit);
2872 D (D_ACCUSE2, (" + Dropping as last in list and next doesn't start a block\n"));
2876 else if (scan->next == NULL)
2878 D (D_ACCUSE2, (" + Dropping as hit the end of the list\n"));
2879 D (D_ACCUSE2, (" + Next in htab: %p\n", next));
2884 if (opIgnoresA (ic, scan->next))
2888 D (D_ACCUSE2_VERBOSE, (" ! Op ignores A, so continue scanning\n"));
2892 D (D_ACCUSE2, (" + Dropping as parts are not consecuitive and intermediate might use A\n"));
2897 while (!bitVectIsZero (uses));
2899 OP_SYMBOL (IC_RESULT (ic))->accuse = ACCUSE_A;
2904 /** Does some transformations to reduce register pressure.
2907 packRegisters (eBBlock * ebp)
2912 D (D_ALLOC, ("packRegisters: entered.\n"));
2914 while (1 && !DISABLE_PACK_ASSIGN)
2917 /* look for assignments of the form */
2918 /* iTempNN = TRueSym (someoperation) SomeOperand */
2920 /* TrueSym := iTempNN:1 */
2921 for (ic = ebp->sch; ic; ic = ic->next)
2923 /* find assignment of the form TrueSym := iTempNN:1 */
2924 if (ic->op == '=' && !POINTER_SET (ic))
2925 change += packRegsForAssign (ic, ebp);
2931 for (ic = ebp->sch; ic; ic = ic->next)
2933 /* Safe: address of a true sym is always constant. */
2934 /* if this is an itemp & result of a address of a true sym
2935 then mark this as rematerialisable */
2936 D (D_ALLOC, ("packRegisters: looping on ic %p\n", ic));
2938 if (ic->op == ADDRESS_OF &&
2939 IS_ITEMP (IC_RESULT (ic)) &&
2940 IS_TRUE_SYMOP (IC_LEFT (ic)) &&
2941 bitVectnBitsOn (OP_DEFS (IC_RESULT (ic))) == 1 &&
2942 !OP_SYMBOL (IC_LEFT (ic))->onStack)
2945 OP_SYMBOL (IC_RESULT (ic))->remat = 1;
2946 OP_SYMBOL (IC_RESULT (ic))->rematiCode = ic;
2947 OP_SYMBOL (IC_RESULT (ic))->usl.spillLoc = NULL;
2950 /* Safe: just propagates the remat flag */
2951 /* if straight assignment then carry remat flag if this is the
2953 if (ic->op == '=' &&
2954 !POINTER_SET (ic) &&
2955 IS_SYMOP (IC_RIGHT (ic)) &&
2956 OP_SYMBOL (IC_RIGHT (ic))->remat &&
2957 bitVectnBitsOn (OP_SYMBOL (IC_RESULT (ic))->defs) <= 1)
2960 OP_SYMBOL (IC_RESULT (ic))->remat =
2961 OP_SYMBOL (IC_RIGHT (ic))->remat;
2962 OP_SYMBOL (IC_RESULT (ic))->rematiCode =
2963 OP_SYMBOL (IC_RIGHT (ic))->rematiCode;
2966 /* if the condition of an if instruction is defined in the
2967 previous instruction then mark the itemp as a conditional */
2968 if ((IS_CONDITIONAL (ic) ||
2969 ((ic->op == BITWISEAND ||
2972 isBitwiseOptimizable (ic))) &&
2973 ic->next && ic->next->op == IFX &&
2974 bitVectnBitsOn (OP_USES(IC_RESULT(ic)))==1 &&
2975 isOperandEqual (IC_RESULT (ic), IC_COND (ic->next)) &&
2976 OP_SYMBOL (IC_RESULT (ic))->liveTo <= ic->next->seq)
2979 OP_SYMBOL (IC_RESULT (ic))->regType = REG_CND;
2984 /* reduce for support function calls */
2985 if (ic->supportRtn || ic->op == '+' || ic->op == '-')
2986 packRegsForSupport (ic, ebp);
2989 /* some cases the redundant moves can
2990 can be eliminated for return statements */
2991 if (ic->op == RETURN || ic->op == SEND)
2993 packRegsForOneuse (ic, IC_LEFT (ic), ebp);
2996 /* if pointer set & left has a size more than
2997 one and right is not in far space */
2998 if (!DISABLE_PACK_ONE_USE &&
3000 /* MLH: no such thing.
3001 !isOperandInFarSpace(IC_RIGHT(ic)) && */
3002 !OP_SYMBOL (IC_RESULT (ic))->remat &&
3003 !IS_OP_RUONLY (IC_RIGHT (ic)) &&
3004 getSize (aggrToPtr (operandType (IC_RESULT (ic)), FALSE)) > 1)
3007 packRegsForOneuse (ic, IC_RESULT (ic), ebp);
3010 /* if pointer get */
3011 if (!DISABLE_PACK_ONE_USE &&
3013 IS_SYMOP (IC_LEFT (ic)) &&
3014 /* MLH: dont have far space
3015 !isOperandInFarSpace(IC_RESULT(ic))&& */
3016 !OP_SYMBOL (IC_LEFT (ic))->remat &&
3017 !IS_OP_RUONLY (IC_RESULT (ic)) &&
3018 getSize (aggrToPtr (operandType (IC_LEFT (ic)), FALSE)) > 1)
3021 packRegsForOneuse (ic, IC_LEFT (ic), ebp);
3024 /* pack registers for accumulator use, when the result of an
3025 arithmetic or bit wise operation has only one use, that use is
3026 immediately following the defintion and the using iCode has
3027 only one operand or has two operands but one is literal & the
3028 result of that operation is not on stack then we can leave the
3029 result of this operation in acc:b combination */
3031 if (!DISABLE_PACK_HL && IS_ITEMP (IC_RESULT (ic)))
3037 packRegsForHLUse (ic);
3041 packRegsForHLUse3 (ic, IC_RESULT (ic), ebp);
3045 if (!DISABLE_PACK_IY && IS_ITEMP (IC_RESULT (ic)) && IS_Z80)
3047 packRegsForIYUse (ic, IC_RESULT (ic), ebp);
3050 if (!DISABLE_PACK_ACC && IS_ITEMP (IC_RESULT (ic)) &&
3051 getSize (operandType (IC_RESULT (ic))) == 1)
3053 packRegsForAccUse2 (ic);
3058 /** Joins together two byte constant pushes into one word push.
3061 joinPushes (iCode *lic)
3065 for (ic = lic; ic; ic = ic->next)
3072 /* Anything past this? */
3077 /* This and the next pushes? */
3078 if (ic->op != IPUSH || uic->op != IPUSH)
3082 /* Both literals? */
3083 if ( !IS_OP_LITERAL (IC_LEFT (ic)) || !IS_OP_LITERAL (IC_LEFT (uic)))
3087 /* Both characters? */
3088 if ( getSize (operandType (IC_LEFT (ic))) != 1 || getSize (operandType (IC_LEFT (uic))) != 1)
3092 /* Pull out the values, make a new type, and create the new iCode for it.
3094 first = (int)operandLitValue ( IC_LEFT (ic));
3095 second = (int)operandLitValue ( IC_LEFT (uic));
3097 sprintf (buffer, "%uu", ((first << 8) | (second & 0xFF)) & 0xFFFFU);
3098 val = constVal (buffer);
3099 SPEC_NOUN (val->type) = V_INT;
3100 IC_LEFT (ic) = operandFromOperand (IC_LEFT (ic));
3101 IC_LEFT (ic)->operand.valOperand = val;
3103 /* Now remove the second one from the list. */
3104 ic->next = uic->next;
3107 /* Patch up the reverse link */
3108 uic->next->prev = ic;
3115 /*-----------------------------------------------------------------*/
3116 /* assignRegisters - assigns registers to each live range as need */
3117 /*-----------------------------------------------------------------*/
3119 z80_assignRegisters (ebbIndex * ebbi)
3121 eBBlock ** ebbs = ebbi->bbOrder;
3122 int count = ebbi->count;
3126 D (D_ALLOC, ("\n-> z80_assignRegisters: entered.\n"));
3128 setToNull ((void *) &_G.funcrUsed);
3129 setToNull ((void *) &_G.totRegAssigned);
3130 _G.stackExtend = _G.dataExtend = 0;
3134 /* DE is required for the code gen. */
3135 _G.nRegs = GBZ80_MAX_REGS;
3136 regsZ80 = _gbz80_regs;
3140 _G.nRegs = Z80_MAX_REGS;
3141 regsZ80 = _z80_regs;
3144 /* change assignments this will remove some
3145 live ranges reducing some register pressure */
3146 for (i = 0; i < count; i++)
3147 packRegisters (ebbs[i]);
3149 /* liveranges probably changed by register packing
3150 so we compute them again */
3151 recomputeLiveRanges (ebbs, count);
3153 if (options.dump_pack)
3154 dumpEbbsToFileExt (DUMP_PACK, ebbi);
3156 /* first determine for each live range the number of
3157 registers & the type of registers required for each */
3160 /* and serially allocate registers */
3161 serialRegAssign (ebbs, count);
3166 /* if stack was extended then tell the user */
3169 /* werror(W_TOOMANY_SPILS,"stack", */
3170 /* _G.stackExtend,currFunc->name,""); */
3176 /* werror(W_TOOMANY_SPILS,"data space", */
3177 /* _G.dataExtend,currFunc->name,""); */
3181 if (options.dump_rassgn) {
3182 dumpEbbsToFileExt (DUMP_RASSGN, ebbi);
3183 dumpLiveRanges (DUMP_LRANGE, liveRanges);
3186 /* after that create the register mask
3187 for each of the instruction */
3188 createRegMask (ebbs, count);
3190 /* now get back the chain */
3191 ic = iCodeLabelOptimize (iCodeFromeBBlock (ebbs, count));
3193 ic = joinPushes (ic);
3195 /* redo that offsets for stacked automatic variables */
3196 redoStackOffsets ();
3200 /* free up any stackSpil locations allocated */
3201 applyToSet (_G.stackSpil, deallocStackSpil);
3203 setToNull ((void *) &_G.stackSpil);
3204 setToNull ((void *) &_G.spiltSet);
3205 /* mark all registers as free */