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 the result is on stack or iaccess then it must be
1752 the same atleast one of the operands */
1753 if (OP_SYMBOL (IC_RESULT (ic))->onStack ||
1754 OP_SYMBOL (IC_RESULT (ic))->iaccess)
1756 /* the operation has only one symbol
1757 operator then we can pack */
1758 if ((IC_LEFT (dic) && !IS_SYMOP (IC_LEFT (dic))) ||
1759 (IC_RIGHT (dic) && !IS_SYMOP (IC_RIGHT (dic))))
1762 if (!((IC_LEFT (dic) &&
1763 IC_RESULT (ic)->key == IC_LEFT (dic)->key) ||
1765 IC_RESULT (ic)->key == IC_RIGHT (dic)->key)))
1769 /* found the definition */
1770 /* replace the result with the result of */
1771 /* this assignment and remove this assignment */
1772 bitVectUnSetBit(OP_SYMBOL(IC_RESULT(dic))->defs,dic->key);
1773 IC_RESULT (dic) = IC_RESULT (ic);
1775 if (IS_ITEMP (IC_RESULT (dic)) && OP_SYMBOL (IC_RESULT (dic))->liveFrom > dic->seq)
1777 OP_SYMBOL (IC_RESULT (dic))->liveFrom = dic->seq;
1779 /* delete from liverange table also
1780 delete from all the points inbetween and the new
1782 for (sic = dic; sic != ic; sic = sic->next)
1784 bitVectUnSetBit (sic->rlive, IC_RESULT (ic)->key);
1785 if (IS_ITEMP (IC_RESULT (dic)))
1786 bitVectSetBit (sic->rlive, IC_RESULT (dic)->key);
1789 remiCodeFromeBBlock (ebp, ic);
1790 // PENDING: Check vs mcs51
1791 bitVectUnSetBit(OP_SYMBOL(IC_RESULT(ic))->defs,ic->key);
1792 hTabDeleteItem (&iCodehTab, ic->key, ic, DELETE_ITEM, NULL);
1793 OP_DEFS(IC_RESULT (dic))=bitVectSetBit (OP_DEFS (IC_RESULT (dic)), dic->key);
1797 /** Scanning backwards looks for first assig found.
1800 findAssignToSym (operand * op, iCode * ic)
1804 for (dic = ic->prev; dic; dic = dic->prev)
1807 /* if definition by assignment */
1808 if (dic->op == '=' &&
1809 !POINTER_SET (dic) &&
1810 IC_RESULT (dic)->key == op->key)
1811 /* && IS_TRUE_SYMOP(IC_RIGHT(dic)) */
1814 /* we are interested only if defined in far space */
1815 /* or in stack space in case of + & - */
1817 /* if assigned to a non-symbol then return
1819 if (!IS_SYMOP (IC_RIGHT (dic)))
1822 /* if the symbol is in far space then
1824 if (isOperandInFarSpace (IC_RIGHT (dic)))
1827 /* for + & - operations make sure that
1828 if it is on the stack it is the same
1829 as one of the three operands */
1830 if ((ic->op == '+' || ic->op == '-') &&
1831 OP_SYMBOL (IC_RIGHT (dic))->onStack)
1834 if (IC_RESULT (ic)->key != IC_RIGHT (dic)->key &&
1835 IC_LEFT (ic)->key != IC_RIGHT (dic)->key &&
1836 IC_RIGHT (ic)->key != IC_RIGHT (dic)->key)
1844 /* if we find an usage then we cannot delete it */
1845 if (IC_LEFT (dic) && IC_LEFT (dic)->key == op->key)
1848 if (IC_RIGHT (dic) && IC_RIGHT (dic)->key == op->key)
1851 if (POINTER_SET (dic) && IC_RESULT (dic)->key == op->key)
1855 /* now make sure that the right side of dic
1856 is not defined between ic & dic */
1859 iCode *sic = dic->next;
1861 for (; sic != ic; sic = sic->next)
1862 if (IC_RESULT (sic) &&
1863 IC_RESULT (sic)->key == IC_RIGHT (dic)->key)
1872 #if !DISABLE_PACKREGSFORSUPPORT
1875 /*-----------------------------------------------------------------*/
1876 /* packRegsForSupport :- reduce some registers for support calls */
1877 /*-----------------------------------------------------------------*/
1879 packRegsForSupport (iCode * ic, eBBlock * ebp)
1882 /* for the left & right operand :- look to see if the
1883 left was assigned a true symbol in far space in that
1884 case replace them */
1885 D (D_ALLOC, ("packRegsForSupport: running on ic %p\n", ic));
1887 if (IS_ITEMP (IC_LEFT (ic)) &&
1888 OP_SYMBOL (IC_LEFT (ic))->liveTo <= ic->seq)
1890 iCode *dic = findAssignToSym (IC_LEFT (ic), ic);
1896 /* found it we need to remove it from the
1898 for (sic = dic; sic != ic; sic = sic->next)
1899 bitVectUnSetBit (sic->rlive, IC_LEFT (ic)->key);
1901 IC_LEFT (ic)->operand.symOperand =
1902 IC_RIGHT (dic)->operand.symOperand;
1903 IC_LEFT (ic)->key = IC_RIGHT (dic)->operand.symOperand->key;
1904 remiCodeFromeBBlock (ebp, dic);
1905 bitVectUnSetBit(OP_SYMBOL(IC_RESULT(dic))->defs,dic->key);
1906 hTabDeleteItem (&iCodehTab, dic->key, dic, DELETE_ITEM, NULL);
1907 // PENDING: Check vs mcs51
1911 /* do the same for the right operand */
1914 IS_ITEMP (IC_RIGHT (ic)) &&
1915 OP_SYMBOL (IC_RIGHT (ic))->liveTo <= ic->seq)
1917 iCode *dic = findAssignToSym (IC_RIGHT (ic), ic);
1923 /* found it we need to remove it from the block */
1924 for (sic = dic; sic != ic; sic = sic->next)
1925 bitVectUnSetBit (sic->rlive, IC_RIGHT (ic)->key);
1927 IC_RIGHT (ic)->operand.symOperand =
1928 IC_RIGHT (dic)->operand.symOperand;
1929 IC_RIGHT (ic)->key = IC_RIGHT (dic)->operand.symOperand->key;
1931 remiCodeFromeBBlock (ebp, dic);
1932 bitVectUnSetBit(OP_SYMBOL(IC_RESULT(dic))->defs,dic->key);
1933 hTabDeleteItem (&iCodehTab, dic->key, dic, DELETE_ITEM, NULL);
1934 // PENDING: vs mcs51
1942 #define IS_OP_RUONLY(x) (x && IS_SYMOP(x) && OP_SYMBOL(x)->ruonly)
1944 /** Will reduce some registers for single use.
1947 packRegsForOneuse (iCode * ic, operand * op, eBBlock * ebp)
1953 D (D_ALLOC, ("packRegsForOneUse: running on ic %p\n", ic));
1955 /* if returning a literal then do nothing */
1959 /* only upto 2 bytes since we cannot predict
1960 the usage of b, & acc */
1961 if (getSize (operandType (op)) > 2)
1964 if (ic->op != RETURN &&
1968 /* this routine will mark the a symbol as used in one
1969 instruction use only && if the defintion is local
1970 (ie. within the basic block) && has only one definition &&
1971 that definiion is either a return value from a
1972 function or does not contain any variables in
1974 uses = bitVectCopy (OP_USES (op));
1975 bitVectUnSetBit (uses, ic->key); /* take away this iCode */
1976 if (!bitVectIsZero (uses)) /* has other uses */
1979 /* if it has only one defintion */
1980 if (bitVectnBitsOn (OP_DEFS (op)) > 1)
1981 return NULL; /* has more than one definition */
1983 /* get the that definition */
1985 hTabItemWithKey (iCodehTab,
1986 bitVectFirstBit (OP_DEFS (op)))))
1989 /* found the definition now check if it is local */
1990 if (dic->seq < ebp->fSeq ||
1991 dic->seq > ebp->lSeq)
1992 return NULL; /* non-local */
1994 /* now check if it is the return from a function call */
1995 if (dic->op == CALL || dic->op == PCALL)
1997 if (ic->op != SEND && ic->op != RETURN &&
1998 !POINTER_SET(ic) && !POINTER_GET(ic))
2000 OP_SYMBOL (op)->ruonly = 1;
2006 /* otherwise check that the definition does
2007 not contain any symbols in far space */
2008 if (isOperandInFarSpace (IC_LEFT (dic)) ||
2009 isOperandInFarSpace (IC_RIGHT (dic)) ||
2010 IS_OP_RUONLY (IC_LEFT (ic)) ||
2011 IS_OP_RUONLY (IC_RIGHT (ic)))
2016 /* if pointer set then make sure the pointer is one byte */
2017 if (POINTER_SET (dic))
2020 if (POINTER_GET (dic))
2025 /* also make sure the intervenening instructions
2026 don't have any thing in far space */
2027 for (dic = dic->next; dic && dic != ic; dic = dic->next)
2029 /* if there is an intervening function call then no */
2030 if (dic->op == CALL || dic->op == PCALL)
2032 /* if pointer set then make sure the pointer
2034 if (POINTER_SET (dic))
2037 if (POINTER_GET (dic))
2040 /* if address of & the result is remat the okay */
2041 if (dic->op == ADDRESS_OF &&
2042 OP_SYMBOL (IC_RESULT (dic))->remat)
2045 /* if left or right or result is in far space */
2046 if (isOperandInFarSpace (IC_LEFT (dic)) ||
2047 isOperandInFarSpace (IC_RIGHT (dic)) ||
2048 isOperandInFarSpace (IC_RESULT (dic)) ||
2049 IS_OP_RUONLY (IC_LEFT (dic)) ||
2050 IS_OP_RUONLY (IC_RIGHT (dic)) ||
2051 IS_OP_RUONLY (IC_RESULT (dic)))
2057 OP_SYMBOL (op)->ruonly = 1;
2061 /*-----------------------------------------------------------------*/
2062 /* isBitwiseOptimizable - requirements of JEAN LOUIS VERN */
2063 /*-----------------------------------------------------------------*/
2065 isBitwiseOptimizable (iCode * ic)
2067 sym_link *rtype = getSpec (operandType (IC_RIGHT (ic)));
2069 /* bitwise operations are considered optimizable
2070 under the following conditions (Jean-Louis VERN)
2082 if (IS_LITERAL (rtype))
2088 Certian assignments involving pointers can be temporarly stored
2099 #if !DISABLE_PACKREGSFORACCUSE
2102 /** Pack registers for acc use.
2103 When the result of this operation is small and short lived it may
2104 be able to be stored in the accumelator.
2107 packRegsForAccUse (iCode * ic)
2111 /* if this is an aggregate, e.g. a one byte char array */
2112 if (IS_AGGREGATE(operandType(IC_RESULT(ic)))) {
2116 /* if + or - then it has to be one byte result */
2117 if ((ic->op == '+' || ic->op == '-')
2118 && getSize (operandType (IC_RESULT (ic))) > 1)
2121 /* if shift operation make sure right side is not a literal */
2122 if (ic->op == RIGHT_OP &&
2123 (isOperandLiteral (IC_RIGHT (ic)) ||
2124 getSize (operandType (IC_RESULT (ic))) > 1))
2127 if (ic->op == LEFT_OP &&
2128 (isOperandLiteral (IC_RIGHT (ic)) ||
2129 getSize (operandType (IC_RESULT (ic))) > 1))
2132 /* has only one definition */
2133 if (bitVectnBitsOn (OP_DEFS (IC_RESULT (ic))) > 1)
2136 /* has only one use */
2137 if (bitVectnBitsOn (OP_USES (IC_RESULT (ic))) > 1)
2140 /* and the usage immediately follows this iCode */
2141 if (!(uic = hTabItemWithKey (iCodehTab,
2142 bitVectFirstBit (OP_USES (IC_RESULT (ic))))))
2145 if (ic->next != uic)
2148 /* if it is a conditional branch then we definitely can */
2152 if (uic->op == JUMPTABLE)
2156 /* if the usage is not is an assignment or an
2157 arithmetic / bitwise / shift operation then not */
2158 if (POINTER_SET (uic) &&
2159 getSize (aggrToPtr (operandType (IC_RESULT (uic)), FALSE)) > 1)
2163 if (uic->op != '=' &&
2164 !IS_ARITHMETIC_OP (uic) &&
2165 !IS_BITWISE_OP (uic) &&
2166 uic->op != LEFT_OP &&
2167 uic->op != RIGHT_OP)
2170 /* if used in ^ operation then make sure right is not a
2172 if (uic->op == '^' && isOperandLiteral (IC_RIGHT (uic)))
2175 /* if shift operation make sure right side is not a literal */
2176 if (uic->op == RIGHT_OP &&
2177 (isOperandLiteral (IC_RIGHT (uic)) ||
2178 getSize (operandType (IC_RESULT (uic))) > 1))
2181 if (uic->op == LEFT_OP &&
2182 (isOperandLiteral (IC_RIGHT (uic)) ||
2183 getSize (operandType (IC_RESULT (uic))) > 1))
2187 /* make sure that the result of this icode is not on the
2188 stack, since acc is used to compute stack offset */
2189 if (IS_TRUE_SYMOP (IC_RESULT (uic)) &&
2190 OP_SYMBOL (IC_RESULT (uic))->onStack)
2195 /* if either one of them in far space then we cannot */
2196 if ((IS_TRUE_SYMOP (IC_LEFT (uic)) &&
2197 isOperandInFarSpace (IC_LEFT (uic))) ||
2198 (IS_TRUE_SYMOP (IC_RIGHT (uic)) &&
2199 isOperandInFarSpace (IC_RIGHT (uic))))
2203 /* if the usage has only one operand then we can */
2204 if (IC_LEFT (uic) == NULL ||
2205 IC_RIGHT (uic) == NULL)
2208 /* make sure this is on the left side if not
2209 a '+' since '+' is commutative */
2210 if (ic->op != '+' &&
2211 IC_LEFT (uic)->key != IC_RESULT (ic)->key)
2214 // See mcs51 ralloc for reasoning
2216 /* if one of them is a literal then we can */
2217 if ((IC_LEFT (uic) && IS_OP_LITERAL (IC_LEFT (uic))) ||
2218 (IC_RIGHT (uic) && IS_OP_LITERAL (IC_RIGHT (uic))))
2225 /** This is confusing :) Guess for now */
2226 if (IC_LEFT (uic)->key == IC_RESULT (ic)->key &&
2227 (IS_ITEMP (IC_RIGHT (uic)) ||
2228 (IS_TRUE_SYMOP (IC_RIGHT (uic)))))
2231 if (IC_RIGHT (uic)->key == IC_RESULT (ic)->key &&
2232 (IS_ITEMP (IC_LEFT (uic)) ||
2233 (IS_TRUE_SYMOP (IC_LEFT (uic)))))
2237 OP_SYMBOL (IC_RESULT (ic))->accuse = ACCUSE_A;
2242 packRegsForHLUse (iCode * ic)
2246 /* PENDING: Could do IFX */
2252 /* has only one definition */
2253 if (bitVectnBitsOn (OP_DEFS (IC_RESULT (ic))) > 1)
2255 D (D_HLUSE, (" + Dropping as has more than one def\n"));
2259 /* has only one use */
2260 if (bitVectnBitsOn (OP_USES (IC_RESULT (ic))) > 1)
2262 D (D_HLUSE, (" + Dropping as has more than one use\n"));
2266 /* and the usage immediately follows this iCode */
2267 if (!(uic = hTabItemWithKey (iCodehTab,
2268 bitVectFirstBit (OP_USES (IC_RESULT (ic))))))
2270 D (D_HLUSE, (" + Dropping as usage isn't in this block\n"));
2274 if (ic->next != uic)
2276 D (D_HLUSE, (" + Dropping as usage doesn't follow this\n"));
2285 if (getSize (operandType (IC_RESULT (ic))) != 2 ||
2286 (IC_LEFT(uic) && getSize (operandType (IC_LEFT (uic))) != 2) ||
2287 (IC_RIGHT(uic) && getSize (operandType (IC_RIGHT (uic))) != 2))
2289 D (D_HLUSE, (" + Dropping as the result size is not 2\n"));
2295 if (ic->op == CAST && uic->op == IPUSH)
2297 if (ic->op == ADDRESS_OF && uic->op == IPUSH)
2299 if (ic->op == ADDRESS_OF && POINTER_GET (uic) && IS_ITEMP( IC_RESULT (uic)))
2301 if (ic->op == CALL && ic->parmBytes == 0 && (uic->op == '-' || uic->op == '+'))
2306 /* Case of assign a constant to offset in a static array. */
2307 if (ic->op == '+' && IS_VALOP (IC_RIGHT (ic)))
2309 if (uic->op == '=' && POINTER_SET (uic))
2313 else if (uic->op == IPUSH && getSize (operandType (IC_LEFT (uic))) == 2)
2320 D (D_HLUSE, (" + Dropping as it's a bad op\n"));
2323 OP_SYMBOL (IC_RESULT (ic))->accuse = ACCUSE_SCRATCH;
2327 packRegsForHLUse3 (iCode * lic, operand * op, eBBlock * ebp)
2332 bool isFirst = TRUE;
2334 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));
2338 if ( OP_SYMBOL(op)->accuse)
2343 if (OP_SYMBOL(op)->remat)
2348 /* Only defined once */
2349 if (bitVectnBitsOn (OP_DEFS (op)) > 1)
2352 if (getSize (operandType (op)) > 2)
2355 /* And this is the definition */
2356 if (bitVectFirstBit (OP_DEFS (op)) != lic->key)
2359 /* first check if any overlapping liverange has already been
2361 if (OP_SYMBOL(op)->clashes)
2363 for (i = 0 ; i < OP_SYMBOL(op)->clashes->size ; i++ )
2365 if (bitVectBitValue(OP_SYMBOL(op)->clashes,i))
2367 sym = hTabItemWithKey(liveRanges,i);
2368 if (sym->accuse == ACCUSE_SCRATCH)
2376 /* Nothing else that clashes with this is using the scratch
2377 register. Scan through all of the intermediate instructions and
2378 see if any of them could nuke HL.
2380 dic = ic = hTabFirstItemWK(iCodeSeqhTab,OP_SYMBOL(op)->liveFrom);
2382 for (; ic && ic->seq <= OP_SYMBOL(op)->liveTo;
2383 ic = hTabNextItem(iCodeSeqhTab, &key))
2387 D (D_PACK_HLUSE3, ("(On %p: op: %u next: %p)\n", ic, ic->op, ic->next));
2392 if (ic->op == ADDRESS_OF)
2394 if (POINTER_GET (ic))
2396 if (ic->op == '=' && !POINTER_SET(ic))
2400 if (IC_RESULT(ic) && IS_SYMOP(IC_RESULT(ic))
2401 && isOperandInDirSpace (IC_RESULT (ic)))
2404 if (IC_LEFT(ic) && IS_SYMOP(IC_LEFT(ic))
2405 && isOperandInDirSpace (IC_LEFT (ic)))
2408 if (IC_RIGHT(ic) && IS_SYMOP(IC_RIGHT(ic))
2409 && isOperandInDirSpace (IC_RIGHT (ic)))
2412 /* Handle the non left/right/result ones first */
2415 if (ic->op == JUMPTABLE)
2424 if (ic->op == IPUSH && isOperandEqual (op, IC_LEFT (ic)))
2427 if (ic->op == SEND && isOperandEqual (op, IC_LEFT (ic)))
2430 if (ic->op == CALL && isOperandEqual (op, IC_RESULT (ic)))
2433 if (ic->op == LEFT_OP && isOperandLiteral (IC_RIGHT (ic)))
2436 if ((ic->op == '=' && !POINTER_SET(ic)) ||
2437 ic->op == UNARYMINUS ||
2446 if (ic->op == '*' && isOperandEqual (op, IC_LEFT (ic)))
2449 if (POINTER_SET (ic) && isOperandEqual (op, IC_RESULT (ic)))
2452 if (POINTER_GET (ic) && isOperandEqual (op, IC_LEFT (ic)))
2455 if (IS_VALOP (IC_RIGHT (ic)) &&
2462 /* By default give up */
2466 D (D_PACK_HLUSE3, ("Succeeded!\n"))
2468 OP_SYMBOL (op)->accuse = ACCUSE_SCRATCH;
2473 packRegsForIYUse (iCode * lic, operand * op, eBBlock * ebp)
2480 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));
2484 if ( OP_SYMBOL(op)->accuse)
2489 if (OP_SYMBOL(op)->remat)
2494 /* Only defined once */
2495 if (bitVectnBitsOn (OP_DEFS (op)) > 1)
2498 /* And this is the definition */
2499 if (bitVectFirstBit (OP_DEFS (op)) != lic->key)
2502 /* first check if any overlapping liverange has already been
2504 if (OP_SYMBOL(op)->clashes)
2506 for (i = 0 ; i < OP_SYMBOL(op)->clashes->size ; i++ )
2508 if (bitVectBitValue(OP_SYMBOL(op)->clashes,i))
2510 sym = hTabItemWithKey(liveRanges,i);
2511 if (sym->accuse == ACCUSE_IY)
2519 /* Only a few instructions can load into IY */
2525 if (getSize (operandType (op)) != 2)
2527 D (D_ACCUSE2, (" + Dropping as operation has size is too big\n"));
2531 /* Nothing else that clashes with this is using the scratch
2532 register. Scan through all of the intermediate instructions and
2533 see if any of them could nuke HL.
2535 dic = ic = hTabFirstItemWK(iCodeSeqhTab,OP_SYMBOL(op)->liveFrom);
2538 for (; ic && ic->seq <= OP_SYMBOL(op)->liveTo;
2539 ic = hTabNextItem(iCodeSeqhTab,&key))
2544 if (ic->op == PCALL ||
2553 /* Be pessamistic. */
2557 D (D_PACK_IY, (" op: %u uses %u result: %d left: %d right: %d\n", ic->op, bitVectBitValue(uses, ic->key),
2558 IC_RESULT(ic) && IS_SYMOP(IC_RESULT(ic)) ? isOperandInDirSpace(IC_RESULT(ic)) : -1,
2559 IC_LEFT(ic) && IS_SYMOP(IC_LEFT(ic)) ? isOperandInDirSpace(IC_LEFT(ic)) : -1,
2560 IC_RIGHT(ic) && IS_SYMOP(IC_RIGHT(ic)) ? isOperandInDirSpace(IC_RIGHT(ic)) : -1
2563 if (IC_RESULT(ic) && IS_SYMOP(IC_RESULT(ic)) &&
2564 isOperandInDirSpace(IC_RESULT(ic)))
2567 if (IC_RIGHT(ic) && IS_SYMOP(IC_RIGHT(ic)) &&
2568 isOperandInDirSpace(IC_RIGHT(ic)))
2571 if (IC_LEFT(ic) && IS_SYMOP(IC_LEFT(ic)) &&
2572 isOperandInDirSpace(IC_LEFT(ic)))
2575 /* Only certain rules will work against IY. Check if this iCode uses
2577 if (bitVectBitValue(uses, ic->key) != 0)
2579 if (ic->op == '=' &&
2580 isOperandEqual(IC_RESULT(ic), op))
2583 if (ic->op == GET_VALUE_AT_ADDRESS &&
2584 isOperandEqual(IC_LEFT(ic), op))
2587 if (isOperandEqual(IC_RESULT(ic), IC_LEFT(ic)) == FALSE)
2590 if (IC_RIGHT (ic) && IS_VALOP (IC_RIGHT (ic)))
2592 if (ic->op == '+' ||
2595 /* Only works if the constant is small */
2596 if (operandLitValue (IC_RIGHT (ic)) < 4)
2605 /* This iCode doesn't use the sym. See if this iCode preserves IY.
2610 /* By default give up */
2614 D (D_PACK_IY, ("Succeeded IY!\n"));
2616 OP_SYMBOL (op)->accuse = ACCUSE_IY;
2620 /** Returns TRUE if this operation can use acc and if it preserves the value.
2623 opPreservesA (iCode * uic)
2627 /* If we've gotten this far then the thing to compare must be
2628 small enough and must be in A.
2633 if (uic->op == JUMPTABLE)
2635 D (D_ACCUSE2, (" + Dropping as operation is a Jumptable\n"));
2639 /* A pointer assign preserves A if A is the left value. */
2640 if (uic->op == '=' && POINTER_SET (uic))
2645 /* if the usage has only one operand then we can */
2646 /* PENDING: check */
2647 if (IC_LEFT (uic) == NULL ||
2648 IC_RIGHT (uic) == NULL)
2650 D (D_ACCUSE2, (" + Dropping as operation has only one operand\n"));
2654 /* PENDING: check this rule */
2655 if (getSize (operandType (IC_RESULT (uic))) > 1)
2657 D (D_ACCUSE2, (" + Dropping as operation has size is too big\n"));
2662 /* Disabled all of the old rules as they weren't verified and have
2663 caused at least one problem.
2668 /** Returns true if this operand preserves the value of A.
2671 opIgnoresA (iCode * ic, iCode * uic)
2673 /* A increment of an iTemp by a constant is OK. */
2674 if ( uic->op == '+' &&
2675 IS_ITEMP (IC_LEFT (uic)) &&
2676 IS_ITEMP (IC_RESULT (uic)) &&
2677 IS_OP_LITERAL (IC_RIGHT (uic)))
2679 unsigned int icount = (unsigned int) floatFromVal (IC_RIGHT (uic)->operand.valOperand);
2681 /* Being an ITEMP means that we're already a symbol. */
2683 IC_RESULT (uic)->operand.symOperand->key == IC_LEFT (uic)->operand.symOperand->key
2689 else if (uic->op == '=' && !POINTER_SET (uic))
2691 /* If they are equal and get optimised out then things are OK. */
2692 if (isOperandEqual (IC_RESULT (uic), IC_RIGHT (uic)))
2694 /* Straight assign is OK. */
2703 /* Some optimisation cases:
2715 ; genAssign (pointer)
2719 want to optimise down to:
2725 So genPointer get is OK
2726 genPlus where the right is constant, left is iTemp, and result is same as left
2727 genAssign (pointer) is OK
2738 ; genAssign (pointer)
2739 ; AOP_STK for _strcpy_to_1_1
2744 want to optimise down to:
2750 So genIfx where IC_COND has size of 1 and is a constant.
2753 /** Pack registers for acc use.
2754 When the result of this operation is small and short lived it may
2755 be able to be stored in the accumulator.
2757 Note that the 'A preserving' list is currently emperical :)
2760 packRegsForAccUse2 (iCode * ic)
2764 D (D_ACCUSE2, ("packRegsForAccUse2: running on ic %p line %u\n", ic, ic->lineno));
2768 /* Filter out all but those 'good' commands */
2770 !POINTER_GET (ic) &&
2773 !IS_BITWISE_OP (ic) &&
2779 ic->op != GETHBIT &&
2782 D (D_ACCUSE2, (" + Dropping as not a 'good' source command\n"));
2786 /* if + or - then it has to be one byte result.
2789 if ((ic->op == '+' || ic->op == '-')
2790 && getSize (operandType (IC_RESULT (ic))) > 1)
2792 D (D_ACCUSE2, (" + Dropping as it's a big + or -\n"));
2796 /* has only one definition */
2797 if (bitVectnBitsOn (OP_DEFS (IC_RESULT (ic))) > 1)
2799 D (D_ACCUSE2, (" + Dropping as it has more than one definition\n"));
2803 /* Right. We may be able to propagate it through if:
2804 For each in the chain of uses the intermediate is OK.
2806 /* Get next with 'uses result' bit on
2807 If this->next == next
2808 Validate use of next
2809 If OK, increase count
2811 /* and the usage immediately follows this iCode */
2812 if (!(uic = hTabItemWithKey (iCodehTab,
2813 bitVectFirstBit (OP_USES (IC_RESULT (ic))))))
2815 D (D_ACCUSE2, (" + Dropping as usage does not follow first\n"));
2820 /* Create a copy of the OP_USES bit vect */
2821 bitVect *uses = bitVectCopy (OP_USES (IC_RESULT (ic)));
2823 iCode *scan = ic, *next;
2827 setBit = bitVectFirstBit (uses);
2828 next = hTabItemWithKey (iCodehTab, setBit);
2829 if (scan->next == next)
2831 D (D_ACCUSE2_VERBOSE, (" ! Is next in line\n"));
2833 bitVectUnSetBit (uses, setBit);
2834 /* Still contigous. */
2835 if (!opPreservesA (next))
2837 D (D_ACCUSE2, (" + Dropping as operation doesn't preserve A\n"));
2840 D (D_ACCUSE2_VERBOSE, (" ! Preserves A, so continue scanning\n"));
2843 else if (scan->next == NULL && bitVectnBitsOn (uses) == 1 && next != NULL)
2845 if (next->prev == NULL)
2847 if (!opPreservesA (next))
2849 D (D_ACCUSE2, (" + Dropping as operation doesn't preserve A #2\n"));
2852 bitVectUnSetBit (uses, setBit);
2857 D (D_ACCUSE2, (" + Dropping as last in list and next doesn't start a block\n"));
2861 else if (scan->next == NULL)
2863 D (D_ACCUSE2, (" + Dropping as hit the end of the list\n"));
2864 D (D_ACCUSE2, (" + Next in htab: %p\n", next));
2869 if (opIgnoresA (ic, scan->next))
2873 D (D_ACCUSE2_VERBOSE, (" ! Op ignores A, so continue scanning\n"));
2877 D (D_ACCUSE2, (" + Dropping as parts are not consecuitive and intermediate might use A\n"));
2882 while (!bitVectIsZero (uses));
2884 OP_SYMBOL (IC_RESULT (ic))->accuse = ACCUSE_A;
2889 /** Does some transformations to reduce register pressure.
2892 packRegisters (eBBlock * ebp)
2897 D (D_ALLOC, ("packRegisters: entered.\n"));
2899 while (1 && !DISABLE_PACK_ASSIGN)
2902 /* look for assignments of the form */
2903 /* iTempNN = TRueSym (someoperation) SomeOperand */
2905 /* TrueSym := iTempNN:1 */
2906 for (ic = ebp->sch; ic; ic = ic->next)
2908 /* find assignment of the form TrueSym := iTempNN:1 */
2909 if (ic->op == '=' && !POINTER_SET (ic))
2910 change += packRegsForAssign (ic, ebp);
2916 for (ic = ebp->sch; ic; ic = ic->next)
2918 /* Safe: address of a true sym is always constant. */
2919 /* if this is an itemp & result of a address of a true sym
2920 then mark this as rematerialisable */
2921 D (D_ALLOC, ("packRegisters: looping on ic %p\n", ic));
2923 if (ic->op == ADDRESS_OF &&
2924 IS_ITEMP (IC_RESULT (ic)) &&
2925 IS_TRUE_SYMOP (IC_LEFT (ic)) &&
2926 bitVectnBitsOn (OP_DEFS (IC_RESULT (ic))) == 1 &&
2927 !OP_SYMBOL (IC_LEFT (ic))->onStack)
2930 OP_SYMBOL (IC_RESULT (ic))->remat = 1;
2931 OP_SYMBOL (IC_RESULT (ic))->rematiCode = ic;
2932 OP_SYMBOL (IC_RESULT (ic))->usl.spillLoc = NULL;
2935 /* Safe: just propagates the remat flag */
2936 /* if straight assignment then carry remat flag if this is the
2938 if (ic->op == '=' &&
2939 !POINTER_SET (ic) &&
2940 IS_SYMOP (IC_RIGHT (ic)) &&
2941 OP_SYMBOL (IC_RIGHT (ic))->remat &&
2942 bitVectnBitsOn (OP_SYMBOL (IC_RESULT (ic))->defs) <= 1)
2945 OP_SYMBOL (IC_RESULT (ic))->remat =
2946 OP_SYMBOL (IC_RIGHT (ic))->remat;
2947 OP_SYMBOL (IC_RESULT (ic))->rematiCode =
2948 OP_SYMBOL (IC_RIGHT (ic))->rematiCode;
2951 /* if the condition of an if instruction is defined in the
2952 previous instruction then mark the itemp as a conditional */
2953 if ((IS_CONDITIONAL (ic) ||
2954 ((ic->op == BITWISEAND ||
2957 isBitwiseOptimizable (ic))) &&
2958 ic->next && ic->next->op == IFX &&
2959 bitVectnBitsOn (OP_USES(IC_RESULT(ic)))==1 &&
2960 isOperandEqual (IC_RESULT (ic), IC_COND (ic->next)) &&
2961 OP_SYMBOL (IC_RESULT (ic))->liveTo <= ic->next->seq)
2964 OP_SYMBOL (IC_RESULT (ic))->regType = REG_CND;
2969 /* reduce for support function calls */
2970 if (ic->supportRtn || ic->op == '+' || ic->op == '-')
2971 packRegsForSupport (ic, ebp);
2974 /* some cases the redundant moves can
2975 can be eliminated for return statements */
2976 if (ic->op == RETURN || ic->op == SEND)
2978 packRegsForOneuse (ic, IC_LEFT (ic), ebp);
2981 /* if pointer set & left has a size more than
2982 one and right is not in far space */
2983 if (!DISABLE_PACK_ONE_USE &&
2985 /* MLH: no such thing.
2986 !isOperandInFarSpace(IC_RIGHT(ic)) && */
2987 !OP_SYMBOL (IC_RESULT (ic))->remat &&
2988 !IS_OP_RUONLY (IC_RIGHT (ic)) &&
2989 getSize (aggrToPtr (operandType (IC_RESULT (ic)), FALSE)) > 1)
2992 packRegsForOneuse (ic, IC_RESULT (ic), ebp);
2995 /* if pointer get */
2996 if (!DISABLE_PACK_ONE_USE &&
2998 IS_SYMOP (IC_LEFT (ic)) &&
2999 /* MLH: dont have far space
3000 !isOperandInFarSpace(IC_RESULT(ic))&& */
3001 !OP_SYMBOL (IC_LEFT (ic))->remat &&
3002 !IS_OP_RUONLY (IC_RESULT (ic)) &&
3003 getSize (aggrToPtr (operandType (IC_LEFT (ic)), FALSE)) > 1)
3006 packRegsForOneuse (ic, IC_LEFT (ic), ebp);
3009 /* pack registers for accumulator use, when the result of an
3010 arithmetic or bit wise operation has only one use, that use is
3011 immediately following the defintion and the using iCode has
3012 only one operand or has two operands but one is literal & the
3013 result of that operation is not on stack then we can leave the
3014 result of this operation in acc:b combination */
3016 if (!DISABLE_PACK_HL && IS_ITEMP (IC_RESULT (ic)))
3022 packRegsForHLUse (ic);
3026 packRegsForHLUse3 (ic, IC_RESULT (ic), ebp);
3030 if (!DISABLE_PACK_IY && IS_ITEMP (IC_RESULT (ic)) && IS_Z80)
3032 packRegsForIYUse (ic, IC_RESULT (ic), ebp);
3035 if (!DISABLE_PACK_ACC && IS_ITEMP (IC_RESULT (ic)) &&
3036 getSize (operandType (IC_RESULT (ic))) == 1)
3038 packRegsForAccUse2 (ic);
3043 /** Joins together two byte constant pushes into one word push.
3046 joinPushes (iCode *lic)
3050 for (ic = lic; ic; ic = ic->next)
3057 /* Anything past this? */
3062 /* This and the next pushes? */
3063 if (ic->op != IPUSH || uic->op != IPUSH)
3067 /* Both literals? */
3068 if ( !IS_OP_LITERAL (IC_LEFT (ic)) || !IS_OP_LITERAL (IC_LEFT (uic)))
3072 /* Both characters? */
3073 if ( getSize (operandType (IC_LEFT (ic))) != 1 || getSize (operandType (IC_LEFT (uic))) != 1)
3077 /* Pull out the values, make a new type, and create the new iCode for it.
3079 first = (int)operandLitValue ( IC_LEFT (ic));
3080 second = (int)operandLitValue ( IC_LEFT (uic));
3082 sprintf (buffer, "%uu", ((first << 8) | (second & 0xFF)) & 0xFFFFU);
3083 val = constVal (buffer);
3084 SPEC_NOUN (val->type) = V_INT;
3085 IC_LEFT (ic) = operandFromOperand (IC_LEFT (ic));
3086 IC_LEFT (ic)->operand.valOperand = val;
3088 /* Now remove the second one from the list. */
3089 ic->next = uic->next;
3092 /* Patch up the reverse link */
3093 uic->next->prev = ic;
3100 /*-----------------------------------------------------------------*/
3101 /* assignRegisters - assigns registers to each live range as need */
3102 /*-----------------------------------------------------------------*/
3104 z80_assignRegisters (ebbIndex * ebbi)
3106 eBBlock ** ebbs = ebbi->bbOrder;
3107 int count = ebbi->count;
3111 D (D_ALLOC, ("\n-> z80_assignRegisters: entered.\n"));
3113 setToNull ((void *) &_G.funcrUsed);
3114 setToNull ((void *) &_G.totRegAssigned);
3115 _G.stackExtend = _G.dataExtend = 0;
3119 /* DE is required for the code gen. */
3120 _G.nRegs = GBZ80_MAX_REGS;
3121 regsZ80 = _gbz80_regs;
3125 _G.nRegs = Z80_MAX_REGS;
3126 regsZ80 = _z80_regs;
3129 /* change assignments this will remove some
3130 live ranges reducing some register pressure */
3131 for (i = 0; i < count; i++)
3132 packRegisters (ebbs[i]);
3134 /* liveranges probably changed by register packing
3135 so we compute them again */
3136 recomputeLiveRanges (ebbs, count);
3138 if (options.dump_pack)
3139 dumpEbbsToFileExt (DUMP_PACK, ebbi);
3141 /* first determine for each live range the number of
3142 registers & the type of registers required for each */
3145 /* and serially allocate registers */
3146 serialRegAssign (ebbs, count);
3151 /* if stack was extended then tell the user */
3154 /* werror(W_TOOMANY_SPILS,"stack", */
3155 /* _G.stackExtend,currFunc->name,""); */
3161 /* werror(W_TOOMANY_SPILS,"data space", */
3162 /* _G.dataExtend,currFunc->name,""); */
3166 if (options.dump_rassgn) {
3167 dumpEbbsToFileExt (DUMP_RASSGN, ebbi);
3168 dumpLiveRanges (DUMP_LRANGE, liveRanges);
3171 /* after that create the register mask
3172 for each of the instruction */
3173 createRegMask (ebbs, count);
3175 /* now get back the chain */
3176 ic = iCodeLabelOptimize (iCodeFromeBBlock (ebbs, count));
3178 ic = joinPushes (ic);
3180 /* redo that offsets for stacked automatic variables */
3181 redoStackOffsets ();
3185 /* free up any stackSpil locations allocated */
3186 applyToSet (_G.stackSpil, deallocStackSpil);
3188 setToNull ((void *) &_G.stackSpil);
3189 setToNull ((void *) &_G.spiltSet);
3190 /* mark all registers as free */