1 /*------------------------------------------------------------------------
3 SDCCralloc.c - source file for register allocation. (ATMEL AVR) specific
5 Written By - Sandeep Dutta . sandeep.dutta@usa.net (1998)
7 This program is free software; you can redistribute it and/or modify it
8 under the terms of the GNU General Public License as published by the
9 Free Software Foundation; either version 2, or (at your option) any
12 This program is distributed in the hope that it will be useful,
13 but WITHOUT ANY WARRANTY; without even the implied warranty of
14 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
15 GNU General Public License for more details.
17 You should have received a copy of the GNU General Public License
18 along with this program; if not, write to the Free Software
19 Foundation, 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
21 In other words, you are welcome to use, share and improve this program.
22 You are forbidden to forbid anyone else to use, share and improve
23 what you give them. Help stamp out software-hoarding!
24 -------------------------------------------------------------------------*/
30 /*-----------------------------------------------------------------*/
31 /* At this point we start getting processor specific although */
32 /* some routines are non-processor specific & can be reused when */
33 /* targetting other processors. The decision for this will have */
34 /* to be made on a routine by routine basis */
35 /* routines used to pack registers are most definitely not reusable */
36 /* since the pack the registers depending strictly on the MCU */
37 /*-----------------------------------------------------------------*/
39 extern void genAVRCode (iCode *);
48 bitVect *funcrUsed; /* registers used in a function */
53 /* Shared with gen.c */
54 int avr_ptrRegReq; /* pointer register required */
58 {REG_GPR|REG_PAIR, R0_IDX, REG_GPR|REG_PAIR, "r0", "r0", "", 0, 0, 0}, /* scratch */
59 {REG_GPR, R1_IDX, REG_GPR , "r1", "r1", "", 0, 0, 0}, /* scratch */
60 {REG_GPR|REG_PAIR, R2_IDX, REG_GPR|REG_PAIR, "r2", "r2", "", 0, 1, 1}, /* gpr */
61 {REG_GPR, R3_IDX, REG_GPR , "r3", "r3", "", 0, 1, 1}, /* gpr */
62 {REG_GPR|REG_PAIR, R4_IDX, REG_GPR|REG_PAIR, "r4", "r4", "", 0, 1, 1}, /* gpr */
63 {REG_GPR, R5_IDX, REG_GPR , "r5", "r5", "", 0, 1, 1}, /* gpr */
64 {REG_GPR|REG_PAIR, R6_IDX, REG_GPR|REG_PAIR, "r6", "r6", "", 0, 1, 1}, /* gpr */
65 {REG_GPR, R7_IDX, REG_GPR , "r7", "r7", "", 0, 1, 1}, /* gpr */
66 {REG_GPR|REG_PAIR, R8_IDX, REG_GPR|REG_PAIR, "r8", "r8", "", 0, 1, 1}, /* gpr */
67 {REG_GPR, R9_IDX, REG_GPR , "r9", "r9", "", 0, 1, 1}, /* gpr */
68 {REG_GPR|REG_PAIR, R10_IDX,REG_GPR|REG_PAIR, "r10", "r10","",0, 1, 1}, /* gpr */
69 {REG_GPR, R11_IDX,REG_GPR , "r11", "r11","",0, 1, 1}, /* gpr */
70 {REG_GPR|REG_PAIR, R12_IDX,REG_GPR|REG_PAIR, "r12", "r12","",0, 1, 1}, /* gpr */
71 {REG_GPR, R13_IDX,REG_GPR , "r13", "r13","",0, 1, 1}, /* gpr */
72 {REG_GPR|REG_PAIR, R14_IDX,REG_GPR|REG_PAIR, "r14", "r14","",0, 1, 1}, /* gpr */
73 {REG_GPR, R15_IDX,REG_GPR , "r15", "r15","",0, 1, 1}, /* gpr */
74 {REG_GPR|REG_PAIR, R16_IDX,REG_GPR|REG_PAIR, "r16", "r16","",0, 1, 0}, /* parm/gpr */
75 {REG_GPR, R17_IDX,REG_GPR , "r17", "r17","",0, 1, 0}, /* parm/gpr */
76 {REG_GPR|REG_PAIR, R18_IDX,REG_GPR|REG_PAIR, "r18", "r18","",0, 1, 0}, /* parm/gpr */
77 {REG_GPR, R19_IDX,REG_GPR , "r19", "r19","",0, 1, 0}, /* parm/gpr */
78 {REG_GPR|REG_PAIR, R20_IDX,REG_GPR|REG_PAIR, "r20", "r20","",0, 1, 0}, /* parm/gpr */
79 {REG_GPR, R21_IDX,REG_GPR , "r21", "r21","",0, 1, 0}, /* parm/gpr */
80 {REG_GPR|REG_PAIR, R22_IDX,REG_GPR|REG_PAIR, "r22", "r22","",0, 1, 0}, /* parm/gpr */
81 {REG_GPR, R23_IDX,REG_GPR , "r23", "r23","",0, 1, 0}, /* parm/gpr */
82 {REG_GPR|REG_PAIR, R24_IDX,REG_GPR|REG_PAIR, "r24", "r24","",0, 0, 0}, /* scratch */
83 {REG_GPR, R25_IDX,REG_GPR , "r25", "r25","",0, 0, 0}, /* scratch */
84 {REG_GPR|REG_PAIR, R26_IDX,REG_GPR|REG_PAIR, "r26", "r26","",0, 1, 1}, /* used as pointer reg X */
85 {REG_GPR, R27_IDX,REG_GPR , "r27", "r27","",0, 1, 1}, /* used as pointer reg X */
86 {REG_GPR|REG_PAIR, R28_IDX,REG_GPR|REG_PAIR, "r28", "r28","",0, 1, 0}, /* stack frame Y */
87 {REG_GPR, R29_IDX,REG_GPR , "r29", "r29","",0, 1, 0}, /* stack frame Y */
88 {REG_GPR|REG_PAIR, R30_IDX,REG_GPR|REG_PAIR, "r30", "r30","",0, 1, 1}, /* used as pointer reg Z */
89 {REG_GPR, R31_IDX,REG_GPR , "r31", "r31","",0, 1, 1}, /* used as pointer reg Z */
90 {REG_PTR, X_IDX, REG_PTR, "X", "X", "", 0, 1, 0},
91 {REG_PTR, Z_IDX, REG_PTR, "Z", "Z", "", 0, 1, 0},
94 int avr_fReg = 0; /* first allocatable register */
96 static void spillThis (symbol *);
100 /*-----------------------------------------------------------------*/
101 /* findAssignToSym : scanning backwards looks for first assig found */
102 /*-----------------------------------------------------------------*/
104 findAssignToSym (operand * op, iCode * ic)
108 for (dic = ic->prev; dic; dic = dic->prev) {
110 /* if definition by assignment */
111 if (dic->op == '=' &&
112 !POINTER_SET (dic) && IC_RESULT (dic)->key == op->key
113 /* && IS_TRUE_SYMOP(IC_RIGHT(dic)) */
116 /* we are interested only if defined in far space */
117 /* or in stack space in case of + & - */
119 /* if assigned to a non-symbol then return
121 if (!IS_SYMOP (IC_RIGHT (dic)))
124 /* if the symbol is in far space then
126 if (isOperandInFarSpace (IC_RIGHT (dic)))
129 /* for + & - operations make sure that
130 if it is on the stack it is the same
131 as one of the three operands */
132 if ((ic->op == '+' || ic->op == '-') &&
133 OP_SYMBOL (IC_RIGHT (dic))->onStack) {
135 if (IC_RESULT (ic)->key != IC_RIGHT (dic)->key
136 && IC_LEFT (ic)->key !=
138 && IC_RIGHT (ic)->key !=
139 IC_RIGHT (dic)->key) return NULL;
146 /* if we find an usage then we cannot delete it */
147 if (IC_LEFT (dic) && IC_LEFT (dic)->key == op->key)
150 if (IC_RIGHT (dic) && IC_RIGHT (dic)->key == op->key)
153 if (POINTER_SET (dic) && IC_RESULT (dic)->key == op->key)
157 /* now make sure that the right side of dic
158 is not defined between ic & dic */
160 iCode *sic = dic->next;
162 for (; sic != ic; sic = sic->next)
163 if (IC_RESULT (sic) &&
164 IC_RESULT (sic)->key == IC_RIGHT (dic)->key)
173 /*-----------------------------------------------------------------*/
174 /* packForPush - hueristics to reduce iCode for pushing */
175 /*-----------------------------------------------------------------*/
177 packForPush (iCode * ic, eBBlock * ebp)
181 if (ic->op != IPUSH || !IS_ITEMP (IC_LEFT (ic)))
184 /* must have only definition & one usage */
185 if (bitVectnBitsOn (OP_DEFS (IC_LEFT (ic))) != 1 ||
186 bitVectnBitsOn (OP_USES (IC_LEFT (ic))) != 1)
189 /* find the definition */
190 if (!(dic = hTabItemWithKey (iCodehTab,
191 bitVectFirstBit (OP_DEFS
195 if (dic->op != '=' || POINTER_SET (dic))
198 /* we now we know that it has one & only one def & use
199 and the that the definition is an assignment */
200 IC_LEFT (ic) = IC_RIGHT (dic);
202 remiCodeFromeBBlock (ebp, dic);
203 hTabDeleteItem (&iCodehTab, dic->key, dic, DELETE_ITEM, NULL);
206 /*-----------------------------------------------------------------*/
207 /* packRegsForSupport :- reduce some registers for support calls */
208 /*-----------------------------------------------------------------*/
210 packRegsForSupport (iCode * ic, eBBlock * ebp)
213 /* for the left & right operand :- look to see if the
214 left was assigned a true symbol in far space in that
216 if (IS_ITEMP (IC_LEFT (ic)) &&
217 OP_SYMBOL (IC_LEFT (ic))->liveTo <= ic->seq) {
218 iCode *dic = findAssignToSym (IC_LEFT (ic), ic);
224 /* found it we need to remove it from the
226 for (sic = dic; sic != ic; sic = sic->next)
227 bitVectUnSetBit (sic->rlive, IC_LEFT (ic)->key);
229 IC_LEFT (ic)->operand.symOperand =
230 IC_RIGHT (dic)->operand.symOperand;
231 IC_LEFT (ic)->key = IC_RIGHT (dic)->operand.symOperand->key;
232 remiCodeFromeBBlock (ebp, dic);
233 hTabDeleteItem (&iCodehTab, dic->key, dic, DELETE_ITEM, NULL);
237 /* do the same for the right operand */
240 IS_ITEMP (IC_RIGHT (ic)) &&
241 OP_SYMBOL (IC_RIGHT (ic))->liveTo <= ic->seq) {
242 iCode *dic = findAssignToSym (IC_RIGHT (ic), ic);
248 /* if this is a subtraction & the result
249 is a true symbol in far space then don't pack */
250 if (ic->op == '-' && IS_TRUE_SYMOP (IC_RESULT (dic))) {
252 getSpec (operandType (IC_RESULT (dic)));
253 if (IN_FARSPACE (SPEC_OCLS (etype)))
256 /* found it we need to remove it from the
258 for (sic = dic; sic != ic; sic = sic->next)
259 bitVectUnSetBit (sic->rlive, IC_RIGHT (ic)->key);
261 IC_RIGHT (ic)->operand.symOperand =
262 IC_RIGHT (dic)->operand.symOperand;
263 IC_RIGHT (ic)->key = IC_RIGHT (dic)->operand.symOperand->key;
265 remiCodeFromeBBlock (ebp, dic);
266 hTabDeleteItem (&iCodehTab, dic->key, dic, DELETE_ITEM, NULL);
273 /*-----------------------------------------------------------------*/
274 /* farSpacePackable - returns the packable icode for far variables */
275 /*-----------------------------------------------------------------*/
277 farSpacePackable (iCode * ic)
281 /* go thru till we find a definition for the
282 symbol on the right */
283 for (dic = ic->prev; dic; dic = dic->prev) {
285 /* if the definition is a call then no */
286 if ((dic->op == CALL || dic->op == PCALL) &&
287 IC_RESULT (dic)->key == IC_RIGHT (ic)->key) {
291 /* if shift by unknown amount then not */
292 if ((dic->op == LEFT_OP || dic->op == RIGHT_OP) &&
293 IC_RESULT (dic)->key == IC_RIGHT (ic)->key)
296 /* if pointer get and size > 1 */
297 if (POINTER_GET (dic) &&
298 getSize (aggrToPtr (operandType (IC_LEFT (dic)), FALSE)) >
301 if (POINTER_SET (dic) &&
302 getSize (aggrToPtr (operandType (IC_RESULT (dic)), FALSE))
306 /* if any three is a true symbol in far space */
307 if (IC_RESULT (dic) &&
308 IS_TRUE_SYMOP (IC_RESULT (dic)) &&
309 isOperandInFarSpace (IC_RESULT (dic)))
312 if (IC_RIGHT (dic) &&
313 IS_TRUE_SYMOP (IC_RIGHT (dic)) &&
314 isOperandInFarSpace (IC_RIGHT (dic)) &&
315 !isOperandEqual (IC_RIGHT (dic), IC_RESULT (ic)))
319 IS_TRUE_SYMOP (IC_LEFT (dic)) &&
320 isOperandInFarSpace (IC_LEFT (dic)) &&
321 !isOperandEqual (IC_LEFT (dic), IC_RESULT (ic)))
324 if (isOperandEqual (IC_RIGHT (ic), IC_RESULT (dic))) {
325 if ((dic->op == LEFT_OP ||
326 dic->op == RIGHT_OP ||
328 IS_OP_LITERAL (IC_RIGHT (dic))) return NULL;
337 /*-----------------------------------------------------------------*/
338 /* rematStr - returns the rematerialized string for a remat var */
339 /*-----------------------------------------------------------------*/
341 rematStr (symbol * sym)
344 iCode *ic = sym->rematiCode;
348 /* if plus or minus print the right hand side */
349 if (ic->op == '+' || ic->op == '-') {
350 sprintf (s, "0x%04x %c ",
351 (int) operandLitValue (IC_RIGHT (ic)),
354 ic = OP_SYMBOL (IC_LEFT (ic))->rematiCode;
358 /* we reached the end */
359 sprintf (s, "%s", OP_SYMBOL (IC_LEFT (ic))->rname);
366 /*-----------------------------------------------------------------*/
367 /* isSpiltOnStack - returns true if the spil location is on stack */
368 /*-----------------------------------------------------------------*/
370 isSpiltOnStack (symbol * sym)
381 if (!sym->usl.spillLoc)
384 etype = getSpec (sym->usl.spillLoc->type);
385 if (IN_STACK (etype))
391 /*-----------------------------------------------------------------*/
392 /* spillLRWithPtrReg :- will spil those live ranges which use PTR */
393 /*-----------------------------------------------------------------*/
395 spillLRWithPtrReg (symbol * forSym)
398 regs *X, *Z, *X1, *Z1;
401 if (!_G.regAssigned || bitVectIsZero (_G.regAssigned))
404 X = avr_regWithIdx (R26_IDX);
405 X1= avr_regWithIdx (R27_IDX);
406 Z = avr_regWithIdx (R30_IDX);
407 Z1= avr_regWithIdx (R31_IDX);
409 /* for all live ranges */
410 for (lrsym = hTabFirstItem (liveRanges, &k); lrsym;
411 lrsym = hTabNextItem (liveRanges, &k)) {
414 /* if no registers assigned to it or
416 /* if it does not overlap with this then
417 not need to spill it */
419 if (lrsym->isspilt || !lrsym->nRegs ||
420 (lrsym->liveTo < forSym->liveFrom)) continue;
422 /* go thru the registers : if it is either
423 r0 or r1 then spil it */
424 for (j = 0; j < lrsym->nRegs; j++)
425 if (lrsym->regs[j] == X || lrsym->regs[j] == Z ||
426 lrsym->regs[j] == X1 || lrsym->regs[j] == Z1) {
435 /*-----------------------------------------------------------------*/
436 /* allocReg - allocates register of given type */
437 /*-----------------------------------------------------------------*/
439 allocReg (short type)
443 for (i = avr_fReg; i < avr_nRegs; i++) {
445 /* if type is given as 0 then any
446 free register will do */
447 if (!type && regsAVR[i].isFree) {
448 regsAVR[i].isFree = 0;
451 bitVectSetBit (currFunc->regsUsed, i);
455 /* other wise look for specific type
457 if (regsAVR[i].isFree && (regsAVR[i].type & type)) {
458 regsAVR[i].isFree = 0;
461 bitVectSetBit (currFunc->regsUsed, i);
468 /*-----------------------------------------------------------------*/
469 /* allocRegPair - allocates register pair of given */
470 /*-----------------------------------------------------------------*/
472 allocRegPair (short type)
476 for (i = avr_fReg; i < avr_nRegs; i++) {
478 /* look for specific type of register pair */
479 if (regsAVR[i].isFree && (regsAVR[i].type & type)
480 && (regsAVR[i].type & REG_PAIR) && regsAVR[i+1].isFree) {
482 regsAVR[i].isFree = 0;
483 regsAVR[i+1].isFree = 0;
486 bitVectSetBit (currFunc->regsUsed, i);
488 bitVectSetBit (currFunc->regsUsed, i+1);
496 /*-----------------------------------------------------------------*/
497 /* avr_regWithIdx - returns pointer to register wit index number */
498 /*-----------------------------------------------------------------*/
500 avr_regWithIdx (int idx)
504 for (i = 0; i < avr_nRegs; i++)
505 if (regsAVR[i].rIdx == idx)
508 werror (E_INTERNAL_ERROR, __FILE__, __LINE__, "regWithIdx not found");
512 /*-----------------------------------------------------------------*/
513 /* freeReg - frees a register */
514 /*-----------------------------------------------------------------*/
522 /*-----------------------------------------------------------------*/
523 /* nFreeRegs - returns number of free registers */
524 /*-----------------------------------------------------------------*/
531 for (i = avr_fReg; i < avr_nRegs; i++)
532 if (regsAVR[i].isFree && regsAVR[i].type & type)
537 /*-----------------------------------------------------------------*/
538 /* nfreeRegsType - free registers with type */
539 /*-----------------------------------------------------------------*/
541 nfreeRegsType (int type)
544 if (type == REG_PTR) {
545 if ((nfr = nFreeRegs (type)) == 0)
546 return nFreeRegs (REG_GPR);
549 return nFreeRegs (type);
552 /*-----------------------------------------------------------------*/
553 /* computeSpillable - given a point find the spillable live ranges */
554 /*-----------------------------------------------------------------*/
556 computeSpillable (iCode * ic)
560 /* spillable live ranges are those that are live at this
561 point . the following categories need to be subtracted
563 a) - those that are already spilt
564 b) - if being used by this one
565 c) - defined by this one */
567 spillable = bitVectCopy (ic->rlive);
568 spillable = bitVectCplAnd (spillable, _G.spiltSet); /* those already spilt */
569 spillable = bitVectCplAnd (spillable, ic->uses); /* used in this one */
570 bitVectUnSetBit (spillable, ic->defKey);
571 spillable = bitVectIntersect (spillable, _G.regAssigned);
576 /*-----------------------------------------------------------------*/
577 /* noSpilLoc - return true if a variable has no spil location */
578 /*-----------------------------------------------------------------*/
580 noSpilLoc (symbol * sym, eBBlock * ebp, iCode * ic)
582 return (sym->usl.spillLoc ? 0 : 1);
585 /*-----------------------------------------------------------------*/
586 /* hasSpilLoc - will return 1 if the symbol has spil location */
587 /*-----------------------------------------------------------------*/
589 hasSpilLoc (symbol * sym, eBBlock * ebp, iCode * ic)
591 return (sym->usl.spillLoc ? 1 : 0);
594 /*-----------------------------------------------------------------*/
595 /* hasSpilLocnoUptr - will return 1 if the symbol has spil location */
596 /* but is not used as a pointer */
597 /*-----------------------------------------------------------------*/
599 hasSpilLocnoUptr (symbol * sym, eBBlock * ebp, iCode * ic)
601 return ((sym->usl.spillLoc && !sym->uptr) ? 1 : 0);
604 /*-----------------------------------------------------------------*/
605 /* rematable - will return 1 if the remat flag is set */
606 /*-----------------------------------------------------------------*/
608 rematable (symbol * sym, eBBlock * ebp, iCode * ic)
613 /*-----------------------------------------------------------------*/
614 /* notUsedInRemaining - not used or defined in remain of the block */
615 /*-----------------------------------------------------------------*/
617 notUsedInRemaining (symbol * sym, eBBlock * ebp, iCode * ic)
619 return ((usedInRemaining (operandFromSymbol (sym), ic) ? 0 : 1) &&
620 allDefsOutOfRange (sym->defs, ic->seq, ebp->lSeq));
623 /*-----------------------------------------------------------------*/
624 /* allLRs - return true for all */
625 /*-----------------------------------------------------------------*/
627 allLRs (symbol * sym, eBBlock * ebp, iCode * ic)
632 /*-----------------------------------------------------------------*/
633 /* liveRangesWith - applies function to a given set of live range */
634 /*-----------------------------------------------------------------*/
636 liveRangesWith (bitVect * lrs,
637 int (func) (symbol *, eBBlock *, iCode *),
638 eBBlock * ebp, iCode * ic)
643 if (!lrs || !lrs->size)
646 for (i = 1; i < lrs->size; i++) {
648 if (!bitVectBitValue (lrs, i))
651 /* if we don't find it in the live range
652 hash table we are in serious trouble */
653 if (!(sym = hTabItemWithKey (liveRanges, i))) {
654 werror (E_INTERNAL_ERROR, __FILE__, __LINE__,
655 "liveRangesWith could not find liveRange");
659 if (func (sym, ebp, ic)
660 && bitVectBitValue (_G.regAssigned,
661 sym->key)) addSetHead (&rset, sym);
668 /*-----------------------------------------------------------------*/
669 /* leastUsedLR - given a set determines which is the least used */
670 /*-----------------------------------------------------------------*/
672 leastUsedLR (set * sset)
674 symbol *sym = NULL, *lsym = NULL;
676 sym = lsym = setFirstItem (sset);
681 for (; lsym; lsym = setNextItem (sset)) {
683 /* if usage is the same then prefer
684 the spill the smaller of the two */
685 if (lsym->used == sym->used)
686 if (getSize (lsym->type) < getSize (sym->type))
690 if (lsym->used < sym->used)
695 setToNull ((void *) &sset);
700 /*-----------------------------------------------------------------*/
701 /* noOverLap - will iterate through the list looking for over lap */
702 /*-----------------------------------------------------------------*/
704 noOverLap (set * itmpStack, symbol * fsym)
709 for (sym = setFirstItem (itmpStack); sym;
710 sym = setNextItem (itmpStack)) {
711 if (sym->liveTo > fsym->liveFrom)
719 /*-----------------------------------------------------------------*/
720 /* isFree - will return 1 if the a free spil location is found */
721 /*-----------------------------------------------------------------*/
726 V_ARG (symbol **, sloc);
727 V_ARG (symbol *, fsym);
729 /* if already found */
733 /* if it is free && and the itmp assigned to
734 this does not have any overlapping live ranges
735 with the one currently being assigned and
736 the size can be accomodated */
738 noOverLap (sym->usl.itmpStack, fsym) &&
739 getSize (sym->type) >= getSize (fsym->type)) {
747 /*-----------------------------------------------------------------*/
748 /* createStackSpil - create a location on the stack to spil */
749 /*-----------------------------------------------------------------*/
751 createStackSpil (symbol * sym)
754 int useXstack, model, noOverlay;
759 /* first go try and find a free one that is already
760 existing on the stack */
761 if (applyToSet (_G.stackSpil, isFree, &sloc, sym)) {
762 /* found a free one : just update & return */
763 sym->usl.spillLoc = sloc;
766 addSetHead (&sloc->usl.itmpStack, sym);
770 /* could not then have to create one , this is the hard part
771 we need to allocate this on the stack : this is really a
772 hack!! but cannot think of anything better at this time */
774 if (sprintf (slocBuffer, "sloc%d", _G.slocNum++) >=
775 sizeof (slocBuffer)) {
777 "***Internal error: slocBuffer overflowed: %s:%d\n",
782 sloc = newiTemp (slocBuffer);
784 /* set the type to the spilling symbol */
785 sloc->type = copyLinkChain (sym->type);
786 sloc->etype = getSpec (sloc->type);
787 SPEC_SCLS (sloc->etype) = S_AUTO;
788 SPEC_EXTR (sloc->etype) = 0;
790 /* we don't allow it to be allocated`
791 onto the external stack since : so we
792 temporarily turn it off ; we also
793 turn off memory model to prevent
794 the spil from going to the external storage
795 and turn off overlaying
798 useXstack = options.useXstack;
799 model = options.model;
800 noOverlay = options.noOverlay;
801 stackAuto = options.stackAuto;
802 options.noOverlay = 1;
803 options.model = options.useXstack = 0;
807 options.useXstack = useXstack;
808 options.model = model;
809 options.noOverlay = noOverlay;
810 options.stackAuto = stackAuto;
811 sloc->isref = 1; /* to prevent compiler warning */
813 /* if it is on the stack then update the stack */
814 if (IN_STACK (sloc->etype)) {
815 currFunc->stack += getSize (sloc->type);
816 _G.stackExtend += getSize (sloc->type);
819 _G.dataExtend += getSize (sloc->type);
821 /* add it to the _G.stackSpil set */
822 addSetHead (&_G.stackSpil, sloc);
823 sym->usl.spillLoc = sloc;
826 /* add it to the set of itempStack set
827 of the spill location */
828 addSetHead (&sloc->usl.itmpStack, sym);
832 /*-----------------------------------------------------------------*/
833 /* spillThis - spils a specific operand */
834 /*-----------------------------------------------------------------*/
836 spillThis (symbol * sym)
839 /* if this is rematerializable or has a spillLocation
840 we are okay, else we need to create a spillLocation
842 if (!(sym->remat || sym->usl.spillLoc))
843 createStackSpil (sym);
846 /* mark it has spilt & put it in the spilt set */
848 _G.spiltSet = bitVectSetBit (_G.spiltSet, sym->key);
850 bitVectUnSetBit (_G.regAssigned, sym->key);
852 for (i = 0; i < sym->nRegs; i++)
855 freeReg (sym->regs[i]);
859 if (sym->usl.spillLoc && !sym->remat)
860 sym->usl.spillLoc->allocreq = 1;
864 /*-----------------------------------------------------------------*/
865 /* selectSpil - select a iTemp to spil : rather a simple procedure */
866 /*-----------------------------------------------------------------*/
868 selectSpil (iCode * ic, eBBlock * ebp, symbol * forSym)
870 bitVect *lrcs = NULL;
874 /* get the spillable live ranges */
875 lrcs = computeSpillable (ic);
877 /* get all live ranges that are rematerizable */
878 if ((selectS = liveRangesWith (lrcs, rematable, ebp, ic))) {
880 /* return the least used of these */
881 return leastUsedLR (selectS);
884 /* if the symbol is local to the block then */
885 if (forSym->liveTo < ebp->lSeq) {
887 /* check if there are any live ranges allocated
888 to registers that are not used in this block */
891 liveRangesWith (lrcs, notUsedInBlock, ebp, ic))) {
892 sym = leastUsedLR (selectS);
893 /* if this is not rematerializable */
901 /* check if there are any live ranges that not
902 used in the remainder of the block */
905 liveRangesWith (lrcs, notUsedInRemaining, ebp, ic))) {
906 sym = leastUsedLR (selectS);
917 /* find live ranges with spillocation && not used as pointers */
918 if ((selectS = liveRangesWith (lrcs, hasSpilLocnoUptr, ebp, ic))) {
920 sym = leastUsedLR (selectS);
921 /* mark this as allocation required */
922 sym->usl.spillLoc->allocreq = 1;
926 /* find live ranges with spillocation */
927 if ((selectS = liveRangesWith (lrcs, hasSpilLoc, ebp, ic))) {
929 sym = leastUsedLR (selectS);
930 sym->usl.spillLoc->allocreq = 1;
934 /* couldn't find then we need to create a spil
935 location on the stack , for which one? the least
937 if ((selectS = liveRangesWith (lrcs, noSpilLoc, ebp, ic))) {
939 /* return a created spil location */
940 sym = createStackSpil (leastUsedLR (selectS));
941 sym->usl.spillLoc->allocreq = 1;
945 /* this is an extreme situation we will spill
946 this one : happens very rarely but it does happen */
952 /*-----------------------------------------------------------------*/
953 /* spilSomething - spil some variable & mark registers as free */
954 /*-----------------------------------------------------------------*/
956 spilSomething (iCode * ic, eBBlock * ebp, symbol * forSym)
961 /* get something we can spil */
962 ssym = selectSpil (ic, ebp, forSym);
964 /* mark it as spilt */
966 _G.spiltSet = bitVectSetBit (_G.spiltSet, ssym->key);
968 /* mark it as not register assigned &
969 take it away from the set */
970 bitVectUnSetBit (_G.regAssigned, ssym->key);
972 /* mark the registers as free */
973 for (i = 0; i < ssym->nRegs; i++)
975 freeReg (ssym->regs[i]);
977 /* if this was a block level spil then insert push & pop
978 at the start & end of block respectively */
979 if (ssym->blockSpil) {
980 iCode *nic = newiCode (IPUSH, operandFromSymbol (ssym), NULL);
981 /* add push to the start of the block */
982 addiCodeToeBBlock (ebp, nic, (ebp->sch->op == LABEL ?
983 ebp->sch->next : ebp->sch));
984 nic = newiCode (IPOP, operandFromSymbol (ssym), NULL);
985 /* add pop to the end of the block */
986 addiCodeToeBBlock (ebp, nic, NULL);
989 /* if spilt because not used in the remainder of the
990 block then add a push before this instruction and
991 a pop at the end of the block */
992 if (ssym->remainSpil) {
994 iCode *nic = newiCode (IPUSH, operandFromSymbol (ssym), NULL);
995 /* add push just before this instruction */
996 addiCodeToeBBlock (ebp, nic, ic);
998 nic = newiCode (IPOP, operandFromSymbol (ssym), NULL);
999 /* add pop to the end of the block */
1000 addiCodeToeBBlock (ebp, nic, NULL);
1009 /*-----------------------------------------------------------------*/
1010 /* getRegPtr - will try for PTR if not a GPR type if not spil */
1011 /*-----------------------------------------------------------------*/
1013 getRegPtr (iCode * ic, eBBlock * ebp, symbol * sym)
1018 /* try for a ptr type */
1019 if ((reg = allocReg (REG_PTR|REG_PAIR)))
1022 /* try for gpr type / pair */
1023 if ((reg = allocReg (REG_GPR|REG_PAIR)))
1026 /* try for gpr type */
1027 if ((reg = allocReg (REG_GPR)))
1030 /* we have to spil */
1031 if (!spilSomething (ic, ebp, sym))
1034 /* this looks like an infinite loop but
1035 in reality selectSpil will abort */
1039 /*-----------------------------------------------------------------*/
1040 /* getRegScr - will try for SCR if not a GPR type if not spil */
1041 /*-----------------------------------------------------------------*/
1043 getRegScr (iCode * ic, eBBlock * ebp, symbol * sym)
1049 /* try for a scratch non-pair */
1050 if ((reg = allocReg (REG_SCR)))
1053 if ((reg = allocReg (REG_GPR)))
1056 /* we have to spil */
1057 if (!spilSomething (ic, ebp, sym))
1060 /* this looks like an infinite loop but
1061 in really selectSpil will abort */
1065 /*-----------------------------------------------------------------*/
1066 /* getRegGpr - will try for GPR if not spil */
1067 /*-----------------------------------------------------------------*/
1069 getRegGpr (iCode * ic, eBBlock * ebp, symbol * sym )
1074 /* try for gpr type */
1075 if ((reg = allocReg (REG_GPR)))
1079 if ((reg = allocReg (REG_PTR)))
1082 /* we have to spil */
1083 if (!spilSomething (ic, ebp, sym))
1086 /* this looks like an infinite loop but
1087 in reality selectSpil will abort */
1091 /*-----------------------------------------------------------------*/
1092 /* symHasReg - symbol has a given register */
1093 /*-----------------------------------------------------------------*/
1095 symHasReg (symbol * sym, regs * reg)
1099 for (i = 0; i < sym->nRegs; i++)
1100 if (sym->regs[i] == reg)
1106 /*-----------------------------------------------------------------*/
1107 /* deassignLRs - check the live to and if they have registers & are */
1108 /* not spilt then free up the registers */
1109 /*-----------------------------------------------------------------*/
1111 deassignLRs (iCode * ic, eBBlock * ebp)
1117 for (sym = hTabFirstItem (liveRanges, &k); sym;
1118 sym = hTabNextItem (liveRanges, &k)) {
1120 symbol *psym = NULL;
1121 /* if it does not end here */
1122 if (sym->liveTo > ic->seq)
1125 /* if it was spilt on stack then we can
1126 mark the stack spil location as free */
1128 if (sym->stackSpil) {
1129 sym->usl.spillLoc->isFree = 1;
1135 if (!bitVectBitValue (_G.regAssigned, sym->key))
1138 /* special case check if this is an IFX &
1139 the privious one was a pop and the
1140 previous one was not spilt then keep track
1142 if (ic->op == IFX && ic->prev &&
1143 ic->prev->op == IPOP &&
1144 !ic->prev->parmPush &&
1145 !OP_SYMBOL (IC_LEFT (ic->prev))->isspilt)
1146 psym = OP_SYMBOL (IC_LEFT (ic->prev));
1151 bitVectUnSetBit (_G.regAssigned, sym->key);
1153 /* if the result of this one needs registers
1154 and does not have it then assign it right
1156 if (IC_RESULT (ic) && !(SKIP_IC2 (ic) || /* not a special icode */
1157 ic->op == JUMPTABLE ||
1162 POINTER_SET (ic)) &&
1163 (result = OP_SYMBOL (IC_RESULT (ic))) && /* has a result */
1164 result->liveTo > ic->seq && /* and will live beyond this */
1165 result->liveTo <= ebp->lSeq && /* does not go beyond this block */
1166 result->liveFrom == ic->seq && /* does not start before here */
1167 result->regType == sym->regType && /* same register types */
1168 result->nRegs && /* which needs registers */
1169 !result->isspilt && /* and does not already have them */
1171 !bitVectBitValue (_G.regAssigned, result->key) &&
1172 /* the number of free regs + number of regs in this LR
1173 can accomodate the what result Needs */
1174 ((nfreeRegsType (result->regType) + sym->nRegs) >= result->nRegs)) {
1176 for (i = 0; i < result->nRegs; i++) {
1178 result->regs[i] = sym->regs[i];
1179 else if (result->regType == REG_SCR)
1180 result->regs[i] = getRegScr (ic, ebp, result);
1182 result->regs[i] = getRegGpr (ic, ebp, result);
1184 _G.regAssigned = bitVectSetBit (_G.regAssigned, result->key);
1188 /* free the remaining */
1189 for (; i < sym->nRegs; i++) {
1191 if (!symHasReg (psym, sym->regs[i]))
1192 freeReg (sym->regs[i]);
1194 else freeReg (sym->regs[i]);
1201 /*-----------------------------------------------------------------*/
1202 /* reassignLR - reassign this to registers */
1203 /*-----------------------------------------------------------------*/
1205 reassignLR (operand * op)
1207 symbol *sym = OP_SYMBOL (op);
1210 /* not spilt any more */
1211 sym->isspilt = sym->blockSpil = sym->remainSpil = 0;
1212 bitVectUnSetBit (_G.spiltSet, sym->key);
1214 _G.regAssigned = bitVectSetBit (_G.regAssigned, sym->key);
1218 for (i = 0; i < sym->nRegs; i++)
1219 sym->regs[i]->isFree = 0;
1222 /*-----------------------------------------------------------------*/
1223 /* willCauseSpill - determines if allocating will cause a spill */
1224 /*-----------------------------------------------------------------*/
1226 willCauseSpill (int nr, int rt)
1228 /* first check if there are any avlb registers
1229 of te type required */
1230 if (rt == REG_PTR) {
1231 /* special case for pointer type
1232 if pointer type not avlb then
1233 check for type gpr */
1234 if (nFreeRegs (rt) >= nr)
1236 if (nFreeRegs (REG_GPR) >= nr)
1240 if (avr_ptrRegReq) {
1241 if (nFreeRegs (rt) >= nr)
1245 if (nFreeRegs (REG_PTR) + nFreeRegs (REG_GPR) >= nr)
1250 /* it will cause a spil */
1254 /*-----------------------------------------------------------------*/
1255 /* positionRegs - the allocator can allocate same registers to res- */
1256 /* ult and operand, if this happens make sure they are in the same */
1257 /* position as the operand otherwise chaos results */
1258 /*-----------------------------------------------------------------*/
1260 positionRegs (symbol * result, symbol * opsym, int lineno)
1262 int count = min (result->nRegs, opsym->nRegs);
1263 int i, j = 0, shared = 0;
1265 /* if the result has been spilt then cannot share */
1270 /* first make sure that they actually share */
1271 for (i = 0; i < count; i++) {
1272 for (j = 0; j < count; j++) {
1273 if (result->regs[i] == opsym->regs[j] && i != j) {
1281 regs *tmp = result->regs[i];
1282 result->regs[i] = result->regs[j];
1283 result->regs[j] = tmp;
1288 /*-----------------------------------------------------------------*/
1289 /* needsPair - heuristic to determine if a pair would be good */
1290 /*-----------------------------------------------------------------*/
1291 static int needsPair (iCode *ic)
1293 symbol *sym = OP_SYMBOL(IC_RESULT(ic));
1294 bitVect *uses_defs =
1295 bitVectUnion(OP_USES (IC_RESULT(ic)),OP_DEFS(IC_RESULT(ic)));
1297 /* if size is less than 2 then NO */
1298 if (sym->nRegs < 2) return 0;
1299 /* if type Pointer then YES */
1300 if (IS_PTR(sym->type)) return 1;
1302 /* go thru the usages of this operand if used with
1303 a constant then yes */
1304 while (!bitVectIsZero(uses_defs)) {
1305 int ikey = bitVectFirstBit(uses_defs);
1306 iCode *uic = hTabItemWithKey(iCodehTab,ikey);
1307 sym_link *otype = NULL;
1308 bitVectUnSetBit(uses_defs,ikey);
1310 otype = (IC_RIGHT(uic) ? operandType(IC_RIGHT(uic)) : NULL);
1311 if (otype && IS_LITERAL(otype)) return 1;
1316 /*-----------------------------------------------------------------*/
1317 /* serialRegAssign - serially allocate registers to the variables */
1318 /*-----------------------------------------------------------------*/
1320 serialRegAssign (eBBlock ** ebbs, int count)
1324 /* for all blocks */
1325 for (i = 0; i < count; i++) {
1329 if (ebbs[i]->noPath &&
1330 (ebbs[i]->entryLabel != entryLabel &&
1331 ebbs[i]->entryLabel != returnLabel))
1334 /* of all instructions do */
1335 for (ic = ebbs[i]->sch; ic; ic = ic->next) {
1337 /* if this is an ipop that means some live
1338 range will have to be assigned again */
1340 reassignLR (IC_LEFT (ic));
1342 /* if result is present && is a true symbol */
1343 if (IC_RESULT (ic) && ic->op != IFX &&
1344 IS_TRUE_SYMOP (IC_RESULT (ic)))
1345 OP_SYMBOL (IC_RESULT (ic))->allocreq = 1;
1347 /* take away registers from live
1348 ranges that end at this instruction */
1349 deassignLRs (ic, ebbs[i]);
1351 /* some don't need registers */
1352 if (SKIP_IC2 (ic) ||
1353 ic->op == JUMPTABLE ||
1357 (IC_RESULT (ic) && POINTER_SET (ic))) continue;
1359 /* now we need to allocate registers
1360 only for the result */
1361 if (IC_RESULT (ic)) {
1362 symbol *sym = OP_SYMBOL (IC_RESULT (ic));
1367 /* if it does not need or is spilt
1368 or is already assigned to registers
1369 or will not live beyond this instructions */
1372 bitVectBitValue (_G.regAssigned, sym->key)
1373 || sym->liveTo <= ic->seq)
1376 /* if some liverange has been spilt at the block level
1377 and this one live beyond this block then spil this
1380 && sym->liveTo > ebbs[i]->lSeq) {
1384 /* if trying to allocate this will cause
1385 a spill and there is nothing to spill
1386 or this one is rematerializable then
1389 willCauseSpill (sym->nRegs,
1391 spillable = computeSpillable (ic);
1392 if (sym->remat || (willCS && bitVectIsZero (spillable))) {
1397 /* If the live range preceeds the point of definition
1398 then ideally we must take into account registers that
1399 have been allocated after sym->liveFrom but freed
1400 before ic->seq. This is complicated, so spill this
1401 symbol instead and let fillGaps handle the allocation. */
1402 if (sym->liveFrom < ic->seq)
1408 /* if it has a spillocation & is used less than
1409 all other live ranges then spill this */
1411 if (sym->usl.spillLoc) {
1412 symbol *leastUsed = leastUsedLR (liveRangesWith (spillable,
1413 allLRs, ebbs[i], ic));
1414 if (leastUsed && leastUsed->used > sym->used) {
1419 /* if none of the liveRanges have a spillLocation then better
1420 to spill this one than anything else already assigned to registers */
1421 if (liveRangesWith(spillable,noSpilLoc,ebbs[i],ic)) {
1428 /* we assign registers to it */
1429 _G.regAssigned = bitVectSetBit (_G.regAssigned, sym->key);
1430 if (needsPair(ic)) {
1433 if (sym->regType == REG_PTR) regtype = REG_PTR;
1434 else if (sym->regType == REG_SCR) regtype = REG_SCR;
1435 else regtype = REG_GPR;
1436 preg = allocRegPair(regtype);
1438 sym->regs[j++] = preg;
1439 sym->regs[j++] = ®sAVR[preg->rIdx+1];
1442 for (; j < sym->nRegs; j++) {
1443 if (sym->regType == REG_PTR)
1444 sym->regs[j] = getRegPtr (ic, ebbs[i], sym);
1445 else if (sym->regType == REG_SCR)
1446 sym->regs[j] = getRegScr (ic, ebbs[i], sym);
1448 sym->regs[j] = getRegGpr (ic, ebbs[i], sym);
1449 /* if the allocation falied which means
1450 this was spilt then break */
1451 if (!sym->regs[j]) break;
1454 /* if it shares registers with operands make sure
1455 that they are in the same position */
1456 if (IC_LEFT (ic) && IS_SYMOP (IC_LEFT (ic)) &&
1457 OP_SYMBOL (IC_LEFT (ic))->nRegs
1459 positionRegs (OP_SYMBOL (IC_RESULT (ic)),
1460 OP_SYMBOL (IC_LEFT (ic)), ic->lineno);
1461 /* do the same for the right operand */
1462 if (IC_RIGHT (ic) && IS_SYMOP (IC_RIGHT (ic))
1463 && OP_SYMBOL (IC_RIGHT (ic))->nRegs)
1464 positionRegs (OP_SYMBOL (IC_RESULT (ic)),
1465 OP_SYMBOL (IC_RIGHT (ic)), ic->lineno);
1472 /*-----------------------------------------------------------------*/
1473 /* rUmaskForOp :- returns register mask for an operand */
1474 /*-----------------------------------------------------------------*/
1476 rUmaskForOp (operand * op)
1482 /* only temporaries are assigned registers */
1486 sym = OP_SYMBOL (op);
1488 /* if spilt or no registers assigned to it
1490 if (sym->isspilt || !sym->nRegs)
1493 rumask = newBitVect (avr_nRegs);
1495 for (j = 0; j < sym->nRegs; j++) {
1496 rumask = bitVectSetBit (rumask, sym->regs[j]->rIdx);
1502 /*-----------------------------------------------------------------*/
1503 /* regsUsedIniCode :- returns bit vector of registers used in iCode */
1504 /*-----------------------------------------------------------------*/
1506 regsUsedIniCode (iCode * ic)
1508 bitVect *rmask = newBitVect (avr_nRegs);
1510 /* do the special cases first */
1511 if (ic->op == IFX) {
1512 rmask = bitVectUnion (rmask, rUmaskForOp (IC_COND (ic)));
1516 /* for the jumptable */
1517 if (ic->op == JUMPTABLE) {
1518 rmask = bitVectUnion (rmask, rUmaskForOp (IC_JTCOND (ic)));
1523 /* of all other cases */
1525 rmask = bitVectUnion (rmask, rUmaskForOp (IC_LEFT (ic)));
1529 rmask = bitVectUnion (rmask, rUmaskForOp (IC_RIGHT (ic)));
1532 rmask = bitVectUnion (rmask, rUmaskForOp (IC_RESULT (ic)));
1538 /*-----------------------------------------------------------------*/
1539 /* createRegMask - for each instruction will determine the regsUsed */
1540 /*-----------------------------------------------------------------*/
1542 createRegMask (eBBlock ** ebbs, int count)
1546 /* for all blocks */
1547 for (i = 0; i < count; i++) {
1550 if (ebbs[i]->noPath &&
1551 (ebbs[i]->entryLabel != entryLabel &&
1552 ebbs[i]->entryLabel != returnLabel))
1555 /* for all instructions */
1556 for (ic = ebbs[i]->sch; ic; ic = ic->next) {
1560 if (SKIP_IC2 (ic) || !ic->rlive)
1563 /* first mark the registers used in this
1565 ic->rUsed = regsUsedIniCode (ic);
1566 _G.funcrUsed = bitVectUnion (_G.funcrUsed, ic->rUsed);
1568 /* now create the register mask for those
1569 registers that are in use : this is a
1570 super set of ic->rUsed */
1571 ic->rMask = newBitVect (avr_nRegs + 1);
1573 /* for all live Ranges alive at this point */
1574 for (j = 1; j < ic->rlive->size; j++) {
1578 /* if not alive then continue */
1579 if (!bitVectBitValue (ic->rlive, j))
1582 /* find the live range we are interested in */
1583 if (!(sym = hTabItemWithKey (liveRanges, j))) {
1584 werror (E_INTERNAL_ERROR, __FILE__,
1586 "createRegMask cannot find live range");
1590 /* if no register assigned to it */
1591 if (!sym->nRegs || sym->isspilt)
1594 /* for all the registers allocated to it */
1595 for (k = 0; k < sym->nRegs; k++) {
1597 int rIdx = sym->regs[k]->rIdx;
1598 ic->rMask = bitVectSetBit (ic-> rMask,rIdx);
1599 /* special case for X & Z registers */
1600 if (rIdx == R26_IDX || rIdx == R27_IDX)
1601 ic->rMask = bitVectSetBit (ic->rMask, X_IDX);
1602 if (rIdx == R30_IDX || rIdx == R31_IDX)
1603 ic->rMask = bitVectSetBit (ic->rMask, Z_IDX);
1612 /*-----------------------------------------------------------------*/
1613 /* regTypeNum - computes the type & number of registers required */
1614 /*-----------------------------------------------------------------*/
1622 /* for each live range do */
1623 for (sym = hTabFirstItem (liveRanges, &k); sym;
1624 sym = hTabNextItem (liveRanges, &k)) {
1626 /* if used zero times then no registers needed */
1627 if ((sym->liveTo - sym->liveFrom) == 0)
1631 /* if the live range is a temporary */
1634 /* if the type is marked as a conditional */
1635 if (sym->regType == REG_CND)
1638 /* if used in return only then we don't
1640 if (sym->ruonly || sym->accuse) {
1641 if (IS_AGGREGATE (sym->type) || sym->isptr)
1643 aggrToPtr (sym->type, FALSE);
1647 /* if the symbol has only one definition &
1648 that definition is a get_pointer and the
1649 pointer we are getting is rematerializable and
1652 if (bitVectnBitsOn (sym->defs) == 1 &&
1653 (ic = hTabItemWithKey (iCodehTab, bitVectFirstBit (sym-> defs)))
1654 && POINTER_GET (ic) && !IS_BITVAR (sym->etype)) {
1656 /* if in data space or idata space then try to
1657 allocate pointer register */
1661 /* if not then we require registers */
1663 ((IS_AGGREGATE (sym->type) || sym->isptr) ?
1664 getSize (sym->type =
1665 aggrToPtr (sym->type,
1666 FALSE)) : getSize (sym->
1669 if (sym->nRegs > 4) {
1671 "allocated more than 4 or 0 registers for type ");
1672 printTypeChain (sym->type, stderr);
1673 fprintf (stderr, "\n");
1676 /* determine the type of register required */
1677 if (sym->nRegs == 2 && /* size is two */
1678 IS_PTR (sym->type) && /* is a pointer */
1679 sym->uptr) { /* has pointer usage i.e. get/set pointer */
1680 sym->regType = REG_PTR;
1684 /* live accross a function call then gpr else scratch */
1685 if (sym->isLiveFcall)
1686 sym->regType = REG_GPR;
1688 sym->regType = REG_SCR;
1692 /* for the first run we don't provide */
1693 /* registers for true symbols we will */
1694 /* see how things go */
1700 /*-----------------------------------------------------------------*/
1701 /* deallocStackSpil - this will set the stack pointer back */
1702 /*-----------------------------------------------------------------*/
1704 DEFSETFUNC (deallocStackSpil)
1712 /*-----------------------------------------------------------------*/
1713 /* packRegsForAssign - register reduction for assignment */
1714 /*-----------------------------------------------------------------*/
1716 packRegsForAssign (iCode * ic, eBBlock * ebp)
1720 if (!IS_ITEMP (IC_RIGHT (ic)) ||
1721 OP_SYMBOL (IC_RIGHT (ic))->isind ||
1722 OP_LIVETO (IC_RIGHT (ic)) > ic->seq) {
1726 /* find the definition of iTempNN scanning backwards if we find a
1727 a use of the true symbol in before we find the definition then
1729 for (dic = ic->prev; dic; dic = dic->prev) {
1731 /* if there is a function call and this is
1732 a parameter & not my parameter then don't pack it */
1733 if ((dic->op == CALL || dic->op == PCALL) &&
1734 (OP_SYMBOL (IC_RESULT (ic))->_isparm &&
1735 !OP_SYMBOL (IC_RESULT (ic))->ismyparm)) {
1743 if (IS_TRUE_SYMOP (IC_RESULT (dic)) &&
1744 IS_OP_VOLATILE (IC_RESULT (dic))) {
1749 if (IS_SYMOP (IC_RESULT (dic)) &&
1750 IC_RESULT (dic)->key == IC_RIGHT (ic)->key) {
1751 if (POINTER_SET (dic))
1757 if (IS_SYMOP (IC_RIGHT (dic)) &&
1758 (IC_RIGHT (dic)->key == IC_RESULT (ic)->key ||
1759 IC_RIGHT (dic)->key == IC_RIGHT (ic)->key)) {
1764 if (IS_SYMOP (IC_LEFT (dic)) &&
1765 (IC_LEFT (dic)->key == IC_RESULT (ic)->key ||
1766 IC_LEFT (dic)->key == IC_RIGHT (ic)->key)) {
1771 if (POINTER_SET (dic) &&
1772 IC_RESULT (dic)->key == IC_RESULT (ic)->key) {
1779 return 0; /* did not find */
1781 /* if the result is on stack or iaccess then it must be
1782 the same atleast one of the operands */
1783 if (OP_SYMBOL (IC_RESULT (ic))->onStack ||
1784 OP_SYMBOL (IC_RESULT (ic))->iaccess) {
1786 /* the operation has only one symbol
1787 operator then we can pack */
1788 if ((IC_LEFT (dic) && !IS_SYMOP (IC_LEFT (dic))) ||
1789 (IC_RIGHT (dic) && !IS_SYMOP (IC_RIGHT (dic))))
1792 if (!((IC_LEFT (dic) &&
1793 IC_RESULT (ic)->key == IC_LEFT (dic)->key) ||
1795 IC_RESULT (ic)->key == IC_RIGHT (dic)->key))) return 0;
1798 /* if in far space & tru symbol then don't */
1799 if ((IS_TRUE_SYMOP (IC_RESULT (ic)))
1800 && isOperandInFarSpace (IC_RESULT (ic))) return 0;
1801 /* found the definition */
1802 /* replace the result with the result of */
1803 /* this assignment and remove this assignment */
1804 IC_RESULT (dic) = IC_RESULT (ic);
1806 if (IS_ITEMP (IC_RESULT (dic))
1807 && OP_SYMBOL (IC_RESULT (dic))->liveFrom > dic->seq) {
1808 OP_SYMBOL (IC_RESULT (dic))->liveFrom = dic->seq;
1810 /* delete from liverange table also
1811 delete from all the points inbetween and the new
1813 for (sic = dic; sic != ic; sic = sic->next) {
1814 bitVectUnSetBit (sic->rlive, IC_RESULT (ic)->key);
1815 if (IS_ITEMP (IC_RESULT (dic)))
1816 bitVectSetBit (sic->rlive, IC_RESULT (dic)->key);
1819 remiCodeFromeBBlock (ebp, ic);
1820 hTabDeleteItem (&iCodehTab, ic->key, ic, DELETE_ITEM, NULL);
1825 #define IS_OP_RUONLY(x) (x && IS_SYMOP(x) && OP_SYMBOL(x)->ruonly)
1828 /*-----------------------------------------------------------------*/
1829 /* packRegsForOneuse : - will reduce some registers for single Use */
1830 /*-----------------------------------------------------------------*/
1832 packRegsForOneuse (iCode * ic, operand * op, eBBlock * ebp)
1837 /* if returning a literal then do nothing */
1842 if (ic->op != RETURN)
1845 /* this routine will mark the a symbol as used in one
1846 instruction use only && if the defintion is local
1847 (ie. within the basic block) && has only one definition &&
1848 that definiion is either a return value from a
1849 function or does not contain any variables in
1851 uses = bitVectCopy (OP_USES (op));
1852 bitVectUnSetBit (uses, ic->key); /* take away this iCode */
1853 if (!bitVectIsZero (uses)) /* has other uses */
1856 /* if it has only one defintion */
1857 if (bitVectnBitsOn (OP_DEFS (op)) > 1)
1858 return NULL; /* has more than one definition */
1860 /* get the that definition */
1862 hTabItemWithKey (iCodehTab,
1863 bitVectFirstBit (OP_DEFS (op))))) return NULL;
1865 /* found the definition now check if it is local */
1866 if (dic->seq < ebp->fSeq || dic->seq > ebp->lSeq)
1867 return NULL; /* non-local */
1869 /* now check if it is the return from
1871 if (dic->op == CALL || dic->op == PCALL) {
1872 if (ic->op != SEND && ic->op != RETURN &&
1873 !POINTER_SET(ic) && !POINTER_GET(ic)) {
1874 OP_SYMBOL (op)->ruonly = 1;
1881 /* otherwise check that the definition does
1882 not contain any symbols in far space */
1883 if (IS_OP_RUONLY (IC_LEFT (ic)) || IS_OP_RUONLY (IC_RIGHT (ic))) {
1887 /* if pointer set then make sure the pointer
1889 if (POINTER_SET (dic) &&
1890 !IS_DATA_PTR (aggrToPtr (operandType (IC_RESULT (dic)), FALSE)))
1893 if (POINTER_GET (dic) &&
1894 !IS_DATA_PTR (aggrToPtr (operandType (IC_LEFT (dic)), FALSE)))
1899 /* also make sure the intervenening instructions
1900 don't have any thing in far space */
1901 for (dic = dic->next; dic && dic != ic; dic = dic->next) {
1903 /* if there is an intervening function call then no */
1904 if (dic->op == CALL || dic->op == PCALL)
1906 /* if pointer set then make sure the pointer
1908 if (POINTER_SET (dic) &&
1909 !IS_DATA_PTR (aggrToPtr
1910 (operandType (IC_RESULT (dic)),
1911 FALSE))) return NULL;
1913 if (POINTER_GET (dic) &&
1914 !IS_DATA_PTR (aggrToPtr
1915 (operandType (IC_LEFT (dic)),
1916 FALSE))) return NULL;
1918 /* if address of & the result is remat the okay */
1919 if (dic->op == ADDRESS_OF &&
1920 OP_SYMBOL (IC_RESULT (dic))->remat) continue;
1922 /* if operand has size of three or more & this
1923 operation is a '*','/' or '%' then 'b' may
1925 if ((dic->op == '%' || dic->op == '/' || dic->op == '*') &&
1926 getSize (operandType (op)) >= 3)
1929 /* if left or right or result is in far space */
1930 if (IS_OP_RUONLY (IC_LEFT (dic)) ||
1931 IS_OP_RUONLY (IC_RIGHT (dic)) ||
1932 IS_OP_RUONLY (IC_RESULT (dic))) {
1937 OP_SYMBOL (op)->ruonly = 1;
1942 /*-----------------------------------------------------------------*/
1943 /* isBitwiseOptimizable - requirements of JEAN LOUIS VERN */
1944 /*-----------------------------------------------------------------*/
1946 isBitwiseOptimizable (iCode * ic)
1948 sym_link *ltype = getSpec (operandType (IC_LEFT (ic)));
1949 sym_link *rtype = getSpec (operandType (IC_RIGHT (ic)));
1951 /* bitwise operations are considered optimizable
1952 under the following conditions (Jean-Louis VERN)
1964 if (IS_LITERAL (rtype) ||
1965 (IS_BITVAR (ltype) && IN_BITSPACE (SPEC_OCLS (ltype))))
1971 /*-----------------------------------------------------------------*/
1972 /* packRegisters - does some transformations to reduce register */
1974 /*-----------------------------------------------------------------*/
1976 packRegisters (eBBlock * ebp)
1985 /* look for assignments of the form */
1986 /* iTempNN = TRueSym (someoperation) SomeOperand */
1988 /* TrueSym := iTempNN:1 */
1989 for (ic = ebp->sch; ic; ic = ic->next) {
1992 /* find assignment of the form TrueSym := iTempNN:1 */
1993 if (ic->op == '=' && !POINTER_SET (ic))
1994 change += packRegsForAssign (ic, ebp);
2001 for (ic = ebp->sch; ic; ic = ic->next) {
2003 /* if this is an itemp & result of a address of a true sym
2004 then mark this as rematerialisable */
2005 if (ic->op == ADDRESS_OF &&
2006 IS_ITEMP (IC_RESULT (ic)) &&
2007 IS_TRUE_SYMOP (IC_LEFT (ic)) &&
2008 bitVectnBitsOn (OP_DEFS (IC_RESULT (ic))) == 1 &&
2009 !OP_SYMBOL (IC_LEFT (ic))->onStack) {
2011 OP_SYMBOL (IC_RESULT (ic))->remat = 1;
2012 OP_SYMBOL (IC_RESULT (ic))->rematiCode = ic;
2013 OP_SYMBOL (IC_RESULT (ic))->usl.spillLoc = NULL;
2017 /* if straight assignment then carry remat flag if
2018 this is the only definition */
2019 if (ic->op == '=' &&
2020 !POINTER_SET (ic) &&
2021 IS_SYMOP (IC_RIGHT (ic)) &&
2022 OP_SYMBOL (IC_RIGHT (ic))->remat &&
2023 bitVectnBitsOn (OP_SYMBOL (IC_RESULT (ic))->defs) <= 1) {
2025 OP_SYMBOL (IC_RESULT (ic))->remat =
2026 OP_SYMBOL (IC_RIGHT (ic))->remat;
2027 OP_SYMBOL (IC_RESULT (ic))->rematiCode =
2028 OP_SYMBOL (IC_RIGHT (ic))->rematiCode;
2031 /* if this is a +/- operation with a rematerizable
2032 then mark this as rematerializable as well only
2033 if the literal value is within the range -255 and + 255
2034 the assembler cannot handle it other wise */
2035 if ((ic->op == '+' || ic->op == '-') &&
2036 (IS_SYMOP (IC_LEFT (ic)) &&
2037 IS_ITEMP (IC_RESULT (ic)) &&
2038 OP_SYMBOL (IC_LEFT (ic))->remat &&
2039 bitVectnBitsOn (OP_DEFS (IC_RESULT (ic))) == 1 &&
2040 IS_OP_LITERAL (IC_RIGHT (ic)))) {
2042 int i = (int) operandLitValue (IC_RIGHT (ic));
2043 if (i < 255 && i > -255) {
2044 OP_SYMBOL (IC_RESULT (ic))->remat = 1;
2045 OP_SYMBOL (IC_RESULT (ic))->rematiCode = ic;
2046 OP_SYMBOL (IC_RESULT (ic))->usl.spillLoc =
2051 /* mark the pointer usages */
2052 if (POINTER_SET (ic))
2053 OP_SYMBOL (IC_RESULT (ic))->uptr = 1;
2055 if (POINTER_GET (ic)) {
2056 OP_SYMBOL (IC_LEFT (ic))->uptr = 1;
2057 if (OP_SYMBOL (IC_LEFT(ic))->remat)
2058 OP_SYMBOL (IC_RESULT (ic))->usl.spillLoc = NULL;
2061 /* if the condition of an if instruction
2062 is defined in the previous instruction then
2063 mark the itemp as a conditional */
2064 if ((IS_CONDITIONAL (ic) ||
2065 ((ic->op == BITWISEAND ||
2068 isBitwiseOptimizable (ic))) &&
2069 ic->next && ic->next->op == IFX &&
2070 isOperandEqual (IC_RESULT (ic), IC_COND (ic->next)) &&
2071 OP_SYMBOL (IC_RESULT (ic))->liveTo <= ic->next->seq) {
2073 OP_SYMBOL (IC_RESULT (ic))->regType = REG_CND;
2077 /* some cases the redundant moves can
2078 can be eliminated for return statements */
2079 if ((ic->op == RETURN || ic->op == SEND))
2080 packRegsForOneuse (ic, IC_LEFT (ic), ebp);
2082 /* if this is cast for intergral promotion then
2083 check if only use of the definition of the
2084 operand being casted/ if yes then replace
2085 the result of that arithmetic operation with
2086 this result and get rid of the cast */
2087 if (ic->op == CAST) {
2088 sym_link *fromType = operandType (IC_RIGHT (ic));
2089 sym_link *toType = operandType (IC_LEFT (ic));
2091 if (IS_INTEGRAL (fromType) && IS_INTEGRAL (toType) &&
2092 getSize (fromType) != getSize (toType) &&
2093 SPEC_USIGN (fromType) == SPEC_USIGN (toType)) {
2096 packRegsForOneuse (ic, IC_RIGHT (ic),
2099 if (IS_ARITHMETIC_OP (dic)) {
2102 remiCodeFromeBBlock (ebp, ic);
2103 hTabDeleteItem (&iCodehTab,
2110 OP_SYMBOL (IC_RIGHT (ic))->
2116 /* if the type from and type to are the same
2117 then if this is the only use then packit */
2118 if (compareType (operandType (IC_RIGHT (ic)),
2119 operandType (IC_LEFT (ic))) ==
2122 packRegsForOneuse (ic,
2128 remiCodeFromeBBlock (ebp, ic);
2129 hTabDeleteItem (&iCodehTab,
2141 /*-----------------------------------------------------------------*/
2142 /* preAssignParms - we have a leaf function preassign registers */
2143 /*-----------------------------------------------------------------*/
2145 preAssignParms (iCode * ic)
2148 /* look for receives and assign registers
2149 to the result of the receives */
2151 /* if it is a receive */
2152 if (ic->op == RECEIVE) {
2153 symbol *r = OP_SYMBOL (IC_RESULT (ic));
2154 int size = getSize (r->type);
2155 if (r->regType == REG_GPR || r->regType == REG_SCR) {
2158 r->regs[j++] = ®sAVR[i++];
2159 regsAVR[i - 1].isFree = 0;
2161 /* put in the regassigned vector */
2163 bitVectSetBit (_G.regAssigned,
2167 /* not a GPR then we should mark as free */
2169 regsAVR[i++].isFree = 1;
2175 /* mark anything remaining as free */
2176 while (i <= R23_IDX)
2177 regsAVR[i++].isFree = 1;
2180 /*-----------------------------------------------------------------*/
2181 /* setdefaultRegs - do setup stuff for register allocation */
2182 /*-----------------------------------------------------------------*/
2184 setDefaultRegs (eBBlock ** ebbs, int count)
2188 /* if no pointer registers required in this function
2189 then mark r26-27 & r30-r31 as GPR & free */
2190 regsAVR[R26_IDX].isFree =
2191 regsAVR[R27_IDX].isFree =
2192 regsAVR[R30_IDX].isFree = regsAVR[R31_IDX].isFree = 1;
2194 if (!avr_ptrRegReq) {
2195 regsAVR[R26_IDX].type = (regsAVR[R26_IDX].type & ~REG_MASK) | REG_GPR;
2196 regsAVR[R27_IDX].type = (regsAVR[R27_IDX].type & ~REG_MASK) | REG_GPR;
2197 regsAVR[R28_IDX].type = (regsAVR[R28_IDX].type & ~REG_MASK) | REG_GPR;
2198 regsAVR[R29_IDX].type = (regsAVR[R29_IDX].type & ~REG_MASK) | REG_GPR;
2201 regsAVR[R26_IDX].type = (regsAVR[R26_IDX].type & ~REG_MASK) | REG_PTR;
2202 regsAVR[R27_IDX].type = (regsAVR[R27_IDX].type & ~REG_MASK) | REG_PTR;
2203 regsAVR[R30_IDX].type = (regsAVR[R30_IDX].type & ~REG_MASK) | REG_PTR;
2204 regsAVR[R31_IDX].type = (regsAVR[R31_IDX].type & ~REG_MASK) | REG_PTR;
2207 /* registers 0-1 / 24-25 used as scratch */
2208 regsAVR[R0_IDX].isFree =
2209 regsAVR[R1_IDX].isFree =
2210 regsAVR[R24_IDX].isFree = regsAVR[R25_IDX].isFree = 0;
2212 /* if this has no function calls then we need
2213 to do something special
2214 a) pre-assign registers to parameters RECEIVE
2215 b) mark the remaining parameter regs as free */
2216 /* mark the parameter regs as SCRACH */
2217 for (i = R16_IDX; i <= R23_IDX; i++) {
2218 regsAVR[i].type = (regsAVR[i].type & ~REG_MASK) | REG_SCR;
2219 regsAVR[i].isFree = 1;
2221 if (!IFFUNC_HASFCALL(currFunc->type)) {
2222 preAssignParms (ebbs[0]->sch);
2224 /* Y - is not allocated (it is the stack frame) */
2225 regsAVR[R28_IDX].isFree = regsAVR[R28_IDX].isFree = 0;
2228 /*-----------------------------------------------------------------*/
2229 /* assignRegisters - assigns registers to each live range as need */
2230 /*-----------------------------------------------------------------*/
2232 avr_assignRegisters (eBBlock ** ebbs, int count)
2237 setToNull ((void *) &_G.funcrUsed);
2238 avr_ptrRegReq = _G.stackExtend = _G.dataExtend = 0;
2240 /* change assignments this will remove some
2241 live ranges reducing some register pressure */
2242 for (i = 0; i < count; i++)
2243 packRegisters (ebbs[i]);
2245 /* liveranges probably changed by register packing
2246 so we compute them again */
2247 recomputeLiveRanges (ebbs, count);
2249 if (options.dump_pack)
2250 dumpEbbsToFileExt (DUMP_PACK, ebbs, count);
2252 /* first determine for each live range the number of
2253 registers & the type of registers required for each */
2256 /* setup the default registers */
2257 setDefaultRegs (ebbs, count);
2259 /* and serially allocate registers */
2260 serialRegAssign (ebbs, count);
2262 /* if stack was extended then tell the user */
2263 if (_G.stackExtend) {
2264 /* werror(W_TOOMANY_SPILS,"stack", */
2265 /* _G.stackExtend,currFunc->name,""); */
2269 if (_G.dataExtend) {
2270 /* werror(W_TOOMANY_SPILS,"data space", */
2271 /* _G.dataExtend,currFunc->name,""); */
2275 /* after that create the register mask
2276 for each of the instruction */
2277 createRegMask (ebbs, count);
2279 /* redo that offsets for stacked automatic variables */
2280 redoStackOffsets ();
2282 if (options.dump_rassgn)
2283 dumpEbbsToFileExt (DUMP_RASSGN, ebbs, count);
2285 /* now get back the chain */
2286 ic = iCodeLabelOptimize (iCodeFromeBBlock (ebbs, count));
2290 /* for (; ic ; ic = ic->next) */
2291 /* piCode(ic,stdout); */
2292 /* free up any _G.stackSpil locations allocated */
2293 applyToSet (_G.stackSpil, deallocStackSpil);
2295 setToNull ((void *) &_G.stackSpil);
2296 setToNull ((void *) &_G.spiltSet);
2297 /* mark all registers as free */