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 */
904 !isiCodeInFunctionCall (ic) &&
906 liveRangesWith (lrcs, notUsedInRemaining, ebp, ic))) {
907 sym = leastUsedLR (selectS);
918 /* find live ranges with spillocation && not used as pointers */
919 if ((selectS = liveRangesWith (lrcs, hasSpilLocnoUptr, ebp, ic))) {
921 sym = leastUsedLR (selectS);
922 /* mark this as allocation required */
923 sym->usl.spillLoc->allocreq = 1;
927 /* find live ranges with spillocation */
928 if ((selectS = liveRangesWith (lrcs, hasSpilLoc, ebp, ic))) {
930 sym = leastUsedLR (selectS);
931 sym->usl.spillLoc->allocreq = 1;
935 /* couldn't find then we need to create a spil
936 location on the stack , for which one? the least
938 if ((selectS = liveRangesWith (lrcs, noSpilLoc, ebp, ic))) {
940 /* return a created spil location */
941 sym = createStackSpil (leastUsedLR (selectS));
942 sym->usl.spillLoc->allocreq = 1;
946 /* this is an extreme situation we will spill
947 this one : happens very rarely but it does happen */
953 /*-----------------------------------------------------------------*/
954 /* spilSomething - spil some variable & mark registers as free */
955 /*-----------------------------------------------------------------*/
957 spilSomething (iCode * ic, eBBlock * ebp, symbol * forSym)
962 /* get something we can spil */
963 ssym = selectSpil (ic, ebp, forSym);
965 /* mark it as spilt */
967 _G.spiltSet = bitVectSetBit (_G.spiltSet, ssym->key);
969 /* mark it as not register assigned &
970 take it away from the set */
971 bitVectUnSetBit (_G.regAssigned, ssym->key);
973 /* mark the registers as free */
974 for (i = 0; i < ssym->nRegs; i++)
976 freeReg (ssym->regs[i]);
978 /* if this was a block level spil then insert push & pop
979 at the start & end of block respectively */
980 if (ssym->blockSpil) {
981 iCode *nic = newiCode (IPUSH, operandFromSymbol (ssym), NULL);
982 /* add push to the start of the block */
983 addiCodeToeBBlock (ebp, nic, (ebp->sch->op == LABEL ?
984 ebp->sch->next : ebp->sch));
985 nic = newiCode (IPOP, operandFromSymbol (ssym), NULL);
986 /* add pop to the end of the block */
987 addiCodeToeBBlock (ebp, nic, NULL);
990 /* if spilt because not used in the remainder of the
991 block then add a push before this instruction and
992 a pop at the end of the block */
993 if (ssym->remainSpil) {
995 iCode *nic = newiCode (IPUSH, operandFromSymbol (ssym), NULL);
996 /* add push just before this instruction */
997 addiCodeToeBBlock (ebp, nic, ic);
999 nic = newiCode (IPOP, operandFromSymbol (ssym), NULL);
1000 /* add pop to the end of the block */
1001 addiCodeToeBBlock (ebp, nic, NULL);
1010 /*-----------------------------------------------------------------*/
1011 /* getRegPtr - will try for PTR if not a GPR type if not spil */
1012 /*-----------------------------------------------------------------*/
1014 getRegPtr (iCode * ic, eBBlock * ebp, symbol * sym)
1019 /* try for a ptr type */
1020 if ((reg = allocReg (REG_PTR|REG_PAIR)))
1023 /* try for gpr type / pair */
1024 if ((reg = allocReg (REG_GPR|REG_PAIR)))
1027 /* try for gpr type */
1028 if ((reg = allocReg (REG_GPR)))
1031 /* we have to spil */
1032 if (!spilSomething (ic, ebp, sym))
1035 /* this looks like an infinite loop but
1036 in reality selectSpil will abort */
1040 /*-----------------------------------------------------------------*/
1041 /* getRegScr - will try for SCR if not a GPR type if not spil */
1042 /*-----------------------------------------------------------------*/
1044 getRegScr (iCode * ic, eBBlock * ebp, symbol * sym)
1050 /* try for a scratch non-pair */
1051 if ((reg = allocReg (REG_SCR)))
1054 if ((reg = allocReg (REG_GPR)))
1057 /* we have to spil */
1058 if (!spilSomething (ic, ebp, sym))
1061 /* this looks like an infinite loop but
1062 in really selectSpil will abort */
1066 /*-----------------------------------------------------------------*/
1067 /* getRegGpr - will try for GPR if not spil */
1068 /*-----------------------------------------------------------------*/
1070 getRegGpr (iCode * ic, eBBlock * ebp, symbol * sym )
1075 /* try for gpr type */
1076 if ((reg = allocReg (REG_GPR)))
1080 if ((reg = allocReg (REG_PTR)))
1083 /* we have to spil */
1084 if (!spilSomething (ic, ebp, sym))
1087 /* this looks like an infinite loop but
1088 in reality selectSpil will abort */
1092 /*-----------------------------------------------------------------*/
1093 /* symHasReg - symbol has a given register */
1094 /*-----------------------------------------------------------------*/
1096 symHasReg (symbol * sym, regs * reg)
1100 for (i = 0; i < sym->nRegs; i++)
1101 if (sym->regs[i] == reg)
1107 /*-----------------------------------------------------------------*/
1108 /* deassignLRs - check the live to and if they have registers & are */
1109 /* not spilt then free up the registers */
1110 /*-----------------------------------------------------------------*/
1112 deassignLRs (iCode * ic, eBBlock * ebp)
1118 for (sym = hTabFirstItem (liveRanges, &k); sym;
1119 sym = hTabNextItem (liveRanges, &k)) {
1121 symbol *psym = NULL;
1122 /* if it does not end here */
1123 if (sym->liveTo > ic->seq)
1126 /* if it was spilt on stack then we can
1127 mark the stack spil location as free */
1129 if (sym->stackSpil) {
1130 sym->usl.spillLoc->isFree = 1;
1136 if (!bitVectBitValue (_G.regAssigned, sym->key))
1139 /* special case check if this is an IFX &
1140 the privious one was a pop and the
1141 previous one was not spilt then keep track
1143 if (ic->op == IFX && ic->prev &&
1144 ic->prev->op == IPOP &&
1145 !ic->prev->parmPush &&
1146 !OP_SYMBOL (IC_LEFT (ic->prev))->isspilt)
1147 psym = OP_SYMBOL (IC_LEFT (ic->prev));
1152 bitVectUnSetBit (_G.regAssigned, sym->key);
1154 /* if the result of this one needs registers
1155 and does not have it then assign it right
1157 if (IC_RESULT (ic) && !(SKIP_IC2 (ic) || /* not a special icode */
1158 ic->op == JUMPTABLE ||
1163 POINTER_SET (ic)) &&
1164 (result = OP_SYMBOL (IC_RESULT (ic))) && /* has a result */
1165 result->liveTo > ic->seq && /* and will live beyond this */
1166 result->liveTo <= ebp->lSeq && /* does not go beyond this block */
1167 result->liveFrom == ic->seq && /* does not start before here */
1168 result->regType == sym->regType && /* same register types */
1169 result->nRegs && /* which needs registers */
1170 !result->isspilt && /* and does not already have them */
1172 !bitVectBitValue (_G.regAssigned, result->key) &&
1173 /* the number of free regs + number of regs in this LR
1174 can accomodate the what result Needs */
1175 ((nfreeRegsType (result->regType) + sym->nRegs) >= result->nRegs)) {
1177 for (i = 0; i < result->nRegs; i++) {
1179 result->regs[i] = sym->regs[i];
1180 else if (result->regType == REG_SCR)
1181 result->regs[i] = getRegScr (ic, ebp, result);
1183 result->regs[i] = getRegGpr (ic, ebp, result);
1185 _G.regAssigned = bitVectSetBit (_G.regAssigned, result->key);
1189 /* free the remaining */
1190 for (; i < sym->nRegs; i++) {
1192 if (!symHasReg (psym, sym->regs[i]))
1193 freeReg (sym->regs[i]);
1195 else freeReg (sym->regs[i]);
1202 /*-----------------------------------------------------------------*/
1203 /* reassignLR - reassign this to registers */
1204 /*-----------------------------------------------------------------*/
1206 reassignLR (operand * op)
1208 symbol *sym = OP_SYMBOL (op);
1211 /* not spilt any more */
1212 sym->isspilt = sym->blockSpil = sym->remainSpil = 0;
1213 bitVectUnSetBit (_G.spiltSet, sym->key);
1215 _G.regAssigned = bitVectSetBit (_G.regAssigned, sym->key);
1219 for (i = 0; i < sym->nRegs; i++)
1220 sym->regs[i]->isFree = 0;
1223 /*-----------------------------------------------------------------*/
1224 /* willCauseSpill - determines if allocating will cause a spill */
1225 /*-----------------------------------------------------------------*/
1227 willCauseSpill (int nr, int rt)
1229 /* first check if there are any avlb registers
1230 of te type required */
1231 if (rt == REG_PTR) {
1232 /* special case for pointer type
1233 if pointer type not avlb then
1234 check for type gpr */
1235 if (nFreeRegs (rt) >= nr)
1237 if (nFreeRegs (REG_GPR) >= nr)
1241 if (avr_ptrRegReq) {
1242 if (nFreeRegs (rt) >= nr)
1246 if (nFreeRegs (REG_PTR) + nFreeRegs (REG_GPR) >= nr)
1251 /* it will cause a spil */
1255 /*-----------------------------------------------------------------*/
1256 /* positionRegs - the allocator can allocate same registers to res- */
1257 /* ult and operand, if this happens make sure they are in the same */
1258 /* position as the operand otherwise chaos results */
1259 /*-----------------------------------------------------------------*/
1261 positionRegs (symbol * result, symbol * opsym, int lineno)
1263 int count = min (result->nRegs, opsym->nRegs);
1264 int i, j = 0, shared = 0;
1266 /* if the result has been spilt then cannot share */
1271 /* first make sure that they actually share */
1272 for (i = 0; i < count; i++) {
1273 for (j = 0; j < count; j++) {
1274 if (result->regs[i] == opsym->regs[j] && i != j) {
1282 regs *tmp = result->regs[i];
1283 result->regs[i] = result->regs[j];
1284 result->regs[j] = tmp;
1289 /*-----------------------------------------------------------------*/
1290 /* needsPair - heuristic to determine if a pair would be good */
1291 /*-----------------------------------------------------------------*/
1292 static int needsPair (iCode *ic)
1294 symbol *sym = OP_SYMBOL(IC_RESULT(ic));
1295 bitVect *uses_defs =
1296 bitVectUnion(OP_USES (IC_RESULT(ic)),OP_DEFS(IC_RESULT(ic)));
1298 /* if size is less than 2 then NO */
1299 if (sym->nRegs < 2) return 0;
1300 /* if type Pointer then YES */
1301 if (IS_PTR(sym->type)) return 1;
1303 /* go thru the usages of this operand if used with
1304 a constant then yes */
1305 while (!bitVectIsZero(uses_defs)) {
1306 int ikey = bitVectFirstBit(uses_defs);
1307 iCode *uic = hTabItemWithKey(iCodehTab,ikey);
1308 sym_link *otype = NULL;
1309 bitVectUnSetBit(uses_defs,ikey);
1311 otype = (IC_RIGHT(uic) ? operandType(IC_RIGHT(uic)) : NULL);
1312 if (otype && IS_LITERAL(otype)) return 1;
1317 /*-----------------------------------------------------------------*/
1318 /* serialRegAssign - serially allocate registers to the variables */
1319 /*-----------------------------------------------------------------*/
1321 serialRegAssign (eBBlock ** ebbs, int count)
1325 /* for all blocks */
1326 for (i = 0; i < count; i++) {
1330 if (ebbs[i]->noPath &&
1331 (ebbs[i]->entryLabel != entryLabel &&
1332 ebbs[i]->entryLabel != returnLabel))
1335 /* of all instructions do */
1336 for (ic = ebbs[i]->sch; ic; ic = ic->next) {
1338 /* if this is an ipop that means some live
1339 range will have to be assigned again */
1341 reassignLR (IC_LEFT (ic));
1343 /* if result is present && is a true symbol */
1344 if (IC_RESULT (ic) && ic->op != IFX &&
1345 IS_TRUE_SYMOP (IC_RESULT (ic)))
1346 OP_SYMBOL (IC_RESULT (ic))->allocreq = 1;
1348 /* take away registers from live
1349 ranges that end at this instruction */
1350 deassignLRs (ic, ebbs[i]);
1352 /* some don't need registers */
1353 if (SKIP_IC2 (ic) ||
1354 ic->op == JUMPTABLE ||
1358 (IC_RESULT (ic) && POINTER_SET (ic))) continue;
1360 /* now we need to allocate registers
1361 only for the result */
1362 if (IC_RESULT (ic)) {
1363 symbol *sym = OP_SYMBOL (IC_RESULT (ic));
1368 /* if it does not need or is spilt
1369 or is already assigned to registers
1370 or will not live beyond this instructions */
1373 bitVectBitValue (_G.regAssigned, sym->key)
1374 || sym->liveTo <= ic->seq)
1377 /* if some liverange has been spilt at the block level
1378 and this one live beyond this block then spil this
1381 && sym->liveTo > ebbs[i]->lSeq) {
1385 /* if trying to allocate this will cause
1386 a spill and there is nothing to spill
1387 or this one is rematerializable then
1390 willCauseSpill (sym->nRegs,
1392 spillable = computeSpillable (ic);
1393 if (sym->remat || (willCS && bitVectIsZero (spillable))) {
1398 /* If the live range preceeds the point of definition
1399 then ideally we must take into account registers that
1400 have been allocated after sym->liveFrom but freed
1401 before ic->seq. This is complicated, so spill this
1402 symbol instead and let fillGaps handle the allocation. */
1403 if (sym->liveFrom < ic->seq)
1409 /* if it has a spillocation & is used less than
1410 all other live ranges then spill this */
1412 if (sym->usl.spillLoc) {
1413 symbol *leastUsed = leastUsedLR (liveRangesWith (spillable,
1414 allLRs, ebbs[i], ic));
1415 if (leastUsed && leastUsed->used > sym->used) {
1420 /* if none of the liveRanges have a spillLocation then better
1421 to spill this one than anything else already assigned to registers */
1422 if (liveRangesWith(spillable,noSpilLoc,ebbs[i],ic)) {
1429 /* we assign registers to it */
1430 _G.regAssigned = bitVectSetBit (_G.regAssigned, sym->key);
1431 if (needsPair(ic)) {
1434 if (sym->regType == REG_PTR) regtype = REG_PTR;
1435 else if (sym->regType == REG_SCR) regtype = REG_SCR;
1436 else regtype = REG_GPR;
1437 preg = allocRegPair(regtype);
1439 sym->regs[j++] = preg;
1440 sym->regs[j++] = ®sAVR[preg->rIdx+1];
1443 for (; j < sym->nRegs; j++) {
1444 if (sym->regType == REG_PTR)
1445 sym->regs[j] = getRegPtr (ic, ebbs[i], sym);
1446 else if (sym->regType == REG_SCR)
1447 sym->regs[j] = getRegScr (ic, ebbs[i], sym);
1449 sym->regs[j] = getRegGpr (ic, ebbs[i], sym);
1450 /* if the allocation falied which means
1451 this was spilt then break */
1452 if (!sym->regs[j]) break;
1455 /* if it shares registers with operands make sure
1456 that they are in the same position */
1457 if (IC_LEFT (ic) && IS_SYMOP (IC_LEFT (ic)) &&
1458 OP_SYMBOL (IC_LEFT (ic))->nRegs
1460 positionRegs (OP_SYMBOL (IC_RESULT (ic)),
1461 OP_SYMBOL (IC_LEFT (ic)), ic->lineno);
1462 /* do the same for the right operand */
1463 if (IC_RIGHT (ic) && IS_SYMOP (IC_RIGHT (ic))
1464 && OP_SYMBOL (IC_RIGHT (ic))->nRegs)
1465 positionRegs (OP_SYMBOL (IC_RESULT (ic)),
1466 OP_SYMBOL (IC_RIGHT (ic)), ic->lineno);
1473 /*-----------------------------------------------------------------*/
1474 /* rUmaskForOp :- returns register mask for an operand */
1475 /*-----------------------------------------------------------------*/
1477 rUmaskForOp (operand * op)
1483 /* only temporaries are assigned registers */
1487 sym = OP_SYMBOL (op);
1489 /* if spilt or no registers assigned to it
1491 if (sym->isspilt || !sym->nRegs)
1494 rumask = newBitVect (avr_nRegs);
1496 for (j = 0; j < sym->nRegs; j++) {
1497 rumask = bitVectSetBit (rumask, sym->regs[j]->rIdx);
1503 /*-----------------------------------------------------------------*/
1504 /* regsUsedIniCode :- returns bit vector of registers used in iCode */
1505 /*-----------------------------------------------------------------*/
1507 regsUsedIniCode (iCode * ic)
1509 bitVect *rmask = newBitVect (avr_nRegs);
1511 /* do the special cases first */
1512 if (ic->op == IFX) {
1513 rmask = bitVectUnion (rmask, rUmaskForOp (IC_COND (ic)));
1517 /* for the jumptable */
1518 if (ic->op == JUMPTABLE) {
1519 rmask = bitVectUnion (rmask, rUmaskForOp (IC_JTCOND (ic)));
1524 /* of all other cases */
1526 rmask = bitVectUnion (rmask, rUmaskForOp (IC_LEFT (ic)));
1530 rmask = bitVectUnion (rmask, rUmaskForOp (IC_RIGHT (ic)));
1533 rmask = bitVectUnion (rmask, rUmaskForOp (IC_RESULT (ic)));
1539 /*-----------------------------------------------------------------*/
1540 /* createRegMask - for each instruction will determine the regsUsed */
1541 /*-----------------------------------------------------------------*/
1543 createRegMask (eBBlock ** ebbs, int count)
1547 /* for all blocks */
1548 for (i = 0; i < count; i++) {
1551 if (ebbs[i]->noPath &&
1552 (ebbs[i]->entryLabel != entryLabel &&
1553 ebbs[i]->entryLabel != returnLabel))
1556 /* for all instructions */
1557 for (ic = ebbs[i]->sch; ic; ic = ic->next) {
1561 if (SKIP_IC2 (ic) || !ic->rlive)
1564 /* first mark the registers used in this
1566 ic->rUsed = regsUsedIniCode (ic);
1567 _G.funcrUsed = bitVectUnion (_G.funcrUsed, ic->rUsed);
1569 /* now create the register mask for those
1570 registers that are in use : this is a
1571 super set of ic->rUsed */
1572 ic->rMask = newBitVect (avr_nRegs + 1);
1574 /* for all live Ranges alive at this point */
1575 for (j = 1; j < ic->rlive->size; j++) {
1579 /* if not alive then continue */
1580 if (!bitVectBitValue (ic->rlive, j))
1583 /* find the live range we are interested in */
1584 if (!(sym = hTabItemWithKey (liveRanges, j))) {
1585 werror (E_INTERNAL_ERROR, __FILE__,
1587 "createRegMask cannot find live range");
1591 /* if no register assigned to it */
1592 if (!sym->nRegs || sym->isspilt)
1595 /* for all the registers allocated to it */
1596 for (k = 0; k < sym->nRegs; k++) {
1598 int rIdx = sym->regs[k]->rIdx;
1599 ic->rMask = bitVectSetBit (ic-> rMask,rIdx);
1600 /* special case for X & Z registers */
1601 if (rIdx == R26_IDX || rIdx == R27_IDX)
1602 ic->rMask = bitVectSetBit (ic->rMask, X_IDX);
1603 if (rIdx == R30_IDX || rIdx == R31_IDX)
1604 ic->rMask = bitVectSetBit (ic->rMask, Z_IDX);
1613 /*-----------------------------------------------------------------*/
1614 /* regTypeNum - computes the type & number of registers required */
1615 /*-----------------------------------------------------------------*/
1623 /* for each live range do */
1624 for (sym = hTabFirstItem (liveRanges, &k); sym;
1625 sym = hTabNextItem (liveRanges, &k)) {
1627 /* if used zero times then no registers needed */
1628 if ((sym->liveTo - sym->liveFrom) == 0)
1632 /* if the live range is a temporary */
1635 /* if the type is marked as a conditional */
1636 if (sym->regType == REG_CND)
1639 /* if used in return only then we don't
1641 if (sym->ruonly || sym->accuse) {
1642 if (IS_AGGREGATE (sym->type) || sym->isptr)
1644 aggrToPtr (sym->type, FALSE);
1648 /* if the symbol has only one definition &
1649 that definition is a get_pointer and the
1650 pointer we are getting is rematerializable and
1653 if (bitVectnBitsOn (sym->defs) == 1 &&
1654 (ic = hTabItemWithKey (iCodehTab, bitVectFirstBit (sym-> defs)))
1655 && POINTER_GET (ic) && !IS_BITVAR (sym->etype)) {
1657 /* if in data space or idata space then try to
1658 allocate pointer register */
1662 /* if not then we require registers */
1664 ((IS_AGGREGATE (sym->type) || sym->isptr) ?
1665 getSize (sym->type =
1666 aggrToPtr (sym->type,
1667 FALSE)) : getSize (sym->
1670 if (sym->nRegs > 4) {
1672 "allocated more than 4 or 0 registers for type ");
1673 printTypeChain (sym->type, stderr);
1674 fprintf (stderr, "\n");
1677 /* determine the type of register required */
1678 if (sym->nRegs == 2 && /* size is two */
1679 IS_PTR (sym->type) && /* is a pointer */
1680 sym->uptr) { /* has pointer usage i.e. get/set pointer */
1681 sym->regType = REG_PTR;
1685 /* live accross a function call then gpr else scratch */
1686 if (sym->isLiveFcall)
1687 sym->regType = REG_GPR;
1689 sym->regType = REG_SCR;
1693 /* for the first run we don't provide */
1694 /* registers for true symbols we will */
1695 /* see how things go */
1701 /*-----------------------------------------------------------------*/
1702 /* deallocStackSpil - this will set the stack pointer back */
1703 /*-----------------------------------------------------------------*/
1705 DEFSETFUNC (deallocStackSpil)
1713 /*-----------------------------------------------------------------*/
1714 /* packRegsForAssign - register reduction for assignment */
1715 /*-----------------------------------------------------------------*/
1717 packRegsForAssign (iCode * ic, eBBlock * ebp)
1721 if (!IS_ITEMP (IC_RIGHT (ic)) ||
1722 OP_SYMBOL (IC_RIGHT (ic))->isind ||
1723 OP_LIVETO (IC_RIGHT (ic)) > ic->seq) {
1727 /* find the definition of iTempNN scanning backwards if we find a
1728 a use of the true symbol in before we find the definition then
1730 for (dic = ic->prev; dic; dic = dic->prev) {
1732 /* if there is a function call and this is
1733 a parameter & not my parameter then don't pack it */
1734 if ((dic->op == CALL || dic->op == PCALL) &&
1735 (OP_SYMBOL (IC_RESULT (ic))->_isparm &&
1736 !OP_SYMBOL (IC_RESULT (ic))->ismyparm)) {
1744 if (IS_TRUE_SYMOP (IC_RESULT (dic)) &&
1745 IS_OP_VOLATILE (IC_RESULT (dic))) {
1750 if (IS_SYMOP (IC_RESULT (dic)) &&
1751 IC_RESULT (dic)->key == IC_RIGHT (ic)->key) {
1752 if (POINTER_SET (dic))
1758 if (IS_SYMOP (IC_RIGHT (dic)) &&
1759 (IC_RIGHT (dic)->key == IC_RESULT (ic)->key ||
1760 IC_RIGHT (dic)->key == IC_RIGHT (ic)->key)) {
1765 if (IS_SYMOP (IC_LEFT (dic)) &&
1766 (IC_LEFT (dic)->key == IC_RESULT (ic)->key ||
1767 IC_LEFT (dic)->key == IC_RIGHT (ic)->key)) {
1772 if (POINTER_SET (dic) &&
1773 IC_RESULT (dic)->key == IC_RESULT (ic)->key) {
1780 return 0; /* did not find */
1782 /* if the result is on stack or iaccess then it must be
1783 the same atleast one of the operands */
1784 if (OP_SYMBOL (IC_RESULT (ic))->onStack ||
1785 OP_SYMBOL (IC_RESULT (ic))->iaccess) {
1787 /* the operation has only one symbol
1788 operator then we can pack */
1789 if ((IC_LEFT (dic) && !IS_SYMOP (IC_LEFT (dic))) ||
1790 (IC_RIGHT (dic) && !IS_SYMOP (IC_RIGHT (dic))))
1793 if (!((IC_LEFT (dic) &&
1794 IC_RESULT (ic)->key == IC_LEFT (dic)->key) ||
1796 IC_RESULT (ic)->key == IC_RIGHT (dic)->key))) return 0;
1799 /* if in far space & tru symbol then don't */
1800 if ((IS_TRUE_SYMOP (IC_RESULT (ic)))
1801 && isOperandInFarSpace (IC_RESULT (ic))) return 0;
1802 /* found the definition */
1803 /* replace the result with the result of */
1804 /* this assignment and remove this assignment */
1805 IC_RESULT (dic) = IC_RESULT (ic);
1807 if (IS_ITEMP (IC_RESULT (dic))
1808 && OP_SYMBOL (IC_RESULT (dic))->liveFrom > dic->seq) {
1809 OP_SYMBOL (IC_RESULT (dic))->liveFrom = dic->seq;
1811 /* delete from liverange table also
1812 delete from all the points inbetween and the new
1814 for (sic = dic; sic != ic; sic = sic->next) {
1815 bitVectUnSetBit (sic->rlive, IC_RESULT (ic)->key);
1816 if (IS_ITEMP (IC_RESULT (dic)))
1817 bitVectSetBit (sic->rlive, IC_RESULT (dic)->key);
1820 remiCodeFromeBBlock (ebp, ic);
1821 hTabDeleteItem (&iCodehTab, ic->key, ic, DELETE_ITEM, NULL);
1826 #define IS_OP_RUONLY(x) (x && IS_SYMOP(x) && OP_SYMBOL(x)->ruonly)
1829 /*-----------------------------------------------------------------*/
1830 /* packRegsForOneuse : - will reduce some registers for single Use */
1831 /*-----------------------------------------------------------------*/
1833 packRegsForOneuse (iCode * ic, operand * op, eBBlock * ebp)
1838 /* if returning a literal then do nothing */
1843 if (ic->op != RETURN)
1846 /* this routine will mark the a symbol as used in one
1847 instruction use only && if the defintion is local
1848 (ie. within the basic block) && has only one definition &&
1849 that definiion is either a return value from a
1850 function or does not contain any variables in
1852 uses = bitVectCopy (OP_USES (op));
1853 bitVectUnSetBit (uses, ic->key); /* take away this iCode */
1854 if (!bitVectIsZero (uses)) /* has other uses */
1857 /* if it has only one defintion */
1858 if (bitVectnBitsOn (OP_DEFS (op)) > 1)
1859 return NULL; /* has more than one definition */
1861 /* get the that definition */
1863 hTabItemWithKey (iCodehTab,
1864 bitVectFirstBit (OP_DEFS (op))))) return NULL;
1866 /* found the definition now check if it is local */
1867 if (dic->seq < ebp->fSeq || dic->seq > ebp->lSeq)
1868 return NULL; /* non-local */
1870 /* now check if it is the return from
1872 if (dic->op == CALL || dic->op == PCALL) {
1873 if (ic->op != SEND && ic->op != RETURN &&
1874 !POINTER_SET(ic) && !POINTER_GET(ic)) {
1875 OP_SYMBOL (op)->ruonly = 1;
1882 /* otherwise check that the definition does
1883 not contain any symbols in far space */
1884 if (IS_OP_RUONLY (IC_LEFT (ic)) || IS_OP_RUONLY (IC_RIGHT (ic))) {
1888 /* if pointer set then make sure the pointer
1890 if (POINTER_SET (dic) &&
1891 !IS_DATA_PTR (aggrToPtr (operandType (IC_RESULT (dic)), FALSE)))
1894 if (POINTER_GET (dic) &&
1895 !IS_DATA_PTR (aggrToPtr (operandType (IC_LEFT (dic)), FALSE)))
1900 /* also make sure the intervenening instructions
1901 don't have any thing in far space */
1902 for (dic = dic->next; dic && dic != ic; dic = dic->next) {
1904 /* if there is an intervening function call then no */
1905 if (dic->op == CALL || dic->op == PCALL)
1907 /* if pointer set then make sure the pointer
1909 if (POINTER_SET (dic) &&
1910 !IS_DATA_PTR (aggrToPtr
1911 (operandType (IC_RESULT (dic)),
1912 FALSE))) return NULL;
1914 if (POINTER_GET (dic) &&
1915 !IS_DATA_PTR (aggrToPtr
1916 (operandType (IC_LEFT (dic)),
1917 FALSE))) return NULL;
1919 /* if address of & the result is remat the okay */
1920 if (dic->op == ADDRESS_OF &&
1921 OP_SYMBOL (IC_RESULT (dic))->remat) continue;
1923 /* if operand has size of three or more & this
1924 operation is a '*','/' or '%' then 'b' may
1926 if ((dic->op == '%' || dic->op == '/' || dic->op == '*') &&
1927 getSize (operandType (op)) >= 3)
1930 /* if left or right or result is in far space */
1931 if (IS_OP_RUONLY (IC_LEFT (dic)) ||
1932 IS_OP_RUONLY (IC_RIGHT (dic)) ||
1933 IS_OP_RUONLY (IC_RESULT (dic))) {
1938 OP_SYMBOL (op)->ruonly = 1;
1943 /*-----------------------------------------------------------------*/
1944 /* isBitwiseOptimizable - requirements of JEAN LOUIS VERN */
1945 /*-----------------------------------------------------------------*/
1947 isBitwiseOptimizable (iCode * ic)
1949 sym_link *ltype = getSpec (operandType (IC_LEFT (ic)));
1950 sym_link *rtype = getSpec (operandType (IC_RIGHT (ic)));
1952 /* bitwise operations are considered optimizable
1953 under the following conditions (Jean-Louis VERN)
1965 if (IS_LITERAL (rtype) ||
1966 (IS_BITVAR (ltype) && IN_BITSPACE (SPEC_OCLS (ltype))))
1972 /*-----------------------------------------------------------------*/
1973 /* packRegisters - does some transformations to reduce register */
1975 /*-----------------------------------------------------------------*/
1977 packRegisters (eBBlock * ebp)
1986 /* look for assignments of the form */
1987 /* iTempNN = TRueSym (someoperation) SomeOperand */
1989 /* TrueSym := iTempNN:1 */
1990 for (ic = ebp->sch; ic; ic = ic->next) {
1993 /* find assignment of the form TrueSym := iTempNN:1 */
1994 if (ic->op == '=' && !POINTER_SET (ic))
1995 change += packRegsForAssign (ic, ebp);
2002 for (ic = ebp->sch; ic; ic = ic->next) {
2004 /* if this is an itemp & result of a address of a true sym
2005 then mark this as rematerialisable */
2006 if (ic->op == ADDRESS_OF &&
2007 IS_ITEMP (IC_RESULT (ic)) &&
2008 IS_TRUE_SYMOP (IC_LEFT (ic)) &&
2009 bitVectnBitsOn (OP_DEFS (IC_RESULT (ic))) == 1 &&
2010 !OP_SYMBOL (IC_LEFT (ic))->onStack) {
2012 OP_SYMBOL (IC_RESULT (ic))->remat = 1;
2013 OP_SYMBOL (IC_RESULT (ic))->rematiCode = ic;
2014 OP_SYMBOL (IC_RESULT (ic))->usl.spillLoc = NULL;
2018 /* if straight assignment then carry remat flag if
2019 this is the only definition */
2020 if (ic->op == '=' &&
2021 !POINTER_SET (ic) &&
2022 IS_SYMOP (IC_RIGHT (ic)) &&
2023 OP_SYMBOL (IC_RIGHT (ic))->remat &&
2024 bitVectnBitsOn (OP_SYMBOL (IC_RESULT (ic))->defs) <= 1) {
2026 OP_SYMBOL (IC_RESULT (ic))->remat =
2027 OP_SYMBOL (IC_RIGHT (ic))->remat;
2028 OP_SYMBOL (IC_RESULT (ic))->rematiCode =
2029 OP_SYMBOL (IC_RIGHT (ic))->rematiCode;
2032 /* if this is a +/- operation with a rematerizable
2033 then mark this as rematerializable as well only
2034 if the literal value is within the range -255 and + 255
2035 the assembler cannot handle it other wise */
2036 if ((ic->op == '+' || ic->op == '-') &&
2037 (IS_SYMOP (IC_LEFT (ic)) &&
2038 IS_ITEMP (IC_RESULT (ic)) &&
2039 OP_SYMBOL (IC_LEFT (ic))->remat &&
2040 bitVectnBitsOn (OP_DEFS (IC_RESULT (ic))) == 1 &&
2041 IS_OP_LITERAL (IC_RIGHT (ic)))) {
2043 int i = (int) operandLitValue (IC_RIGHT (ic));
2044 if (i < 255 && i > -255) {
2045 OP_SYMBOL (IC_RESULT (ic))->remat = 1;
2046 OP_SYMBOL (IC_RESULT (ic))->rematiCode = ic;
2047 OP_SYMBOL (IC_RESULT (ic))->usl.spillLoc =
2052 /* mark the pointer usages */
2053 if (POINTER_SET (ic))
2054 OP_SYMBOL (IC_RESULT (ic))->uptr = 1;
2056 if (POINTER_GET (ic)) {
2057 OP_SYMBOL (IC_LEFT (ic))->uptr = 1;
2058 if (OP_SYMBOL (IC_LEFT(ic))->remat)
2059 OP_SYMBOL (IC_RESULT (ic))->usl.spillLoc = NULL;
2062 /* if the condition of an if instruction
2063 is defined in the previous instruction then
2064 mark the itemp as a conditional */
2065 if ((IS_CONDITIONAL (ic) ||
2066 ((ic->op == BITWISEAND ||
2069 isBitwiseOptimizable (ic))) &&
2070 ic->next && ic->next->op == IFX &&
2071 isOperandEqual (IC_RESULT (ic), IC_COND (ic->next)) &&
2072 OP_SYMBOL (IC_RESULT (ic))->liveTo <= ic->next->seq) {
2074 OP_SYMBOL (IC_RESULT (ic))->regType = REG_CND;
2078 /* some cases the redundant moves can
2079 can be eliminated for return statements */
2080 if ((ic->op == RETURN || ic->op == SEND))
2081 packRegsForOneuse (ic, IC_LEFT (ic), ebp);
2083 /* if this is cast for intergral promotion then
2084 check if only use of the definition of the
2085 operand being casted/ if yes then replace
2086 the result of that arithmetic operation with
2087 this result and get rid of the cast */
2088 if (ic->op == CAST) {
2089 sym_link *fromType = operandType (IC_RIGHT (ic));
2090 sym_link *toType = operandType (IC_LEFT (ic));
2092 if (IS_INTEGRAL (fromType) && IS_INTEGRAL (toType) &&
2093 getSize (fromType) != getSize (toType) &&
2094 SPEC_USIGN (fromType) == SPEC_USIGN (toType)) {
2097 packRegsForOneuse (ic, IC_RIGHT (ic),
2100 if (IS_ARITHMETIC_OP (dic)) {
2103 remiCodeFromeBBlock (ebp, ic);
2104 hTabDeleteItem (&iCodehTab,
2111 OP_SYMBOL (IC_RIGHT (ic))->
2117 /* if the type from and type to are the same
2118 then if this is the only use then packit */
2119 if (compareType (operandType (IC_RIGHT (ic)),
2120 operandType (IC_LEFT (ic))) ==
2123 packRegsForOneuse (ic,
2129 remiCodeFromeBBlock (ebp, ic);
2130 hTabDeleteItem (&iCodehTab,
2142 /*-----------------------------------------------------------------*/
2143 /* preAssignParms - we have a leaf function preassign registers */
2144 /*-----------------------------------------------------------------*/
2146 preAssignParms (iCode * ic)
2149 /* look for receives and assign registers
2150 to the result of the receives */
2152 /* if it is a receive */
2153 if (ic->op == RECEIVE) {
2154 symbol *r = OP_SYMBOL (IC_RESULT (ic));
2155 int size = getSize (r->type);
2156 if (r->regType == REG_GPR || r->regType == REG_SCR) {
2159 r->regs[j++] = ®sAVR[i++];
2160 regsAVR[i - 1].isFree = 0;
2162 /* put in the regassigned vector */
2164 bitVectSetBit (_G.regAssigned,
2168 /* not a GPR then we should mark as free */
2170 regsAVR[i++].isFree = 1;
2176 /* mark anything remaining as free */
2177 while (i <= R23_IDX)
2178 regsAVR[i++].isFree = 1;
2181 /*-----------------------------------------------------------------*/
2182 /* setdefaultRegs - do setup stuff for register allocation */
2183 /*-----------------------------------------------------------------*/
2185 setDefaultRegs (eBBlock ** ebbs, int count)
2189 /* if no pointer registers required in this function
2190 then mark r26-27 & r30-r31 as GPR & free */
2191 regsAVR[R26_IDX].isFree =
2192 regsAVR[R27_IDX].isFree =
2193 regsAVR[R30_IDX].isFree = regsAVR[R31_IDX].isFree = 1;
2195 if (!avr_ptrRegReq) {
2196 regsAVR[R26_IDX].type = (regsAVR[R26_IDX].type & ~REG_MASK) | REG_GPR;
2197 regsAVR[R27_IDX].type = (regsAVR[R27_IDX].type & ~REG_MASK) | REG_GPR;
2198 regsAVR[R28_IDX].type = (regsAVR[R28_IDX].type & ~REG_MASK) | REG_GPR;
2199 regsAVR[R29_IDX].type = (regsAVR[R29_IDX].type & ~REG_MASK) | REG_GPR;
2202 regsAVR[R26_IDX].type = (regsAVR[R26_IDX].type & ~REG_MASK) | REG_PTR;
2203 regsAVR[R27_IDX].type = (regsAVR[R27_IDX].type & ~REG_MASK) | REG_PTR;
2204 regsAVR[R30_IDX].type = (regsAVR[R30_IDX].type & ~REG_MASK) | REG_PTR;
2205 regsAVR[R31_IDX].type = (regsAVR[R31_IDX].type & ~REG_MASK) | REG_PTR;
2208 /* registers 0-1 / 24-25 used as scratch */
2209 regsAVR[R0_IDX].isFree =
2210 regsAVR[R1_IDX].isFree =
2211 regsAVR[R24_IDX].isFree = regsAVR[R25_IDX].isFree = 0;
2213 /* if this has no function calls then we need
2214 to do something special
2215 a) pre-assign registers to parameters RECEIVE
2216 b) mark the remaining parameter regs as free */
2217 /* mark the parameter regs as SCRACH */
2218 for (i = R16_IDX; i <= R23_IDX; i++) {
2219 regsAVR[i].type = (regsAVR[i].type & ~REG_MASK) | REG_SCR;
2220 regsAVR[i].isFree = 1;
2222 if (!IFFUNC_HASFCALL(currFunc->type)) {
2223 preAssignParms (ebbs[0]->sch);
2225 /* Y - is not allocated (it is the stack frame) */
2226 regsAVR[R28_IDX].isFree = regsAVR[R28_IDX].isFree = 0;
2229 /*-----------------------------------------------------------------*/
2230 /* assignRegisters - assigns registers to each live range as need */
2231 /*-----------------------------------------------------------------*/
2233 avr_assignRegisters (eBBlock ** ebbs, int count)
2238 setToNull ((void *) &_G.funcrUsed);
2239 avr_ptrRegReq = _G.stackExtend = _G.dataExtend = 0;
2241 /* change assignments this will remove some
2242 live ranges reducing some register pressure */
2243 for (i = 0; i < count; i++)
2244 packRegisters (ebbs[i]);
2246 /* liveranges probably changed by register packing
2247 so we compute them again */
2248 recomputeLiveRanges (ebbs, count);
2250 if (options.dump_pack)
2251 dumpEbbsToFileExt (DUMP_PACK, ebbs, count);
2253 /* first determine for each live range the number of
2254 registers & the type of registers required for each */
2257 /* setup the default registers */
2258 setDefaultRegs (ebbs, count);
2260 /* and serially allocate registers */
2261 serialRegAssign (ebbs, count);
2263 /* if stack was extended then tell the user */
2264 if (_G.stackExtend) {
2265 /* werror(W_TOOMANY_SPILS,"stack", */
2266 /* _G.stackExtend,currFunc->name,""); */
2270 if (_G.dataExtend) {
2271 /* werror(W_TOOMANY_SPILS,"data space", */
2272 /* _G.dataExtend,currFunc->name,""); */
2276 /* after that create the register mask
2277 for each of the instruction */
2278 createRegMask (ebbs, count);
2280 /* redo that offsets for stacked automatic variables */
2281 redoStackOffsets ();
2283 if (options.dump_rassgn)
2284 dumpEbbsToFileExt (DUMP_RASSGN, ebbs, count);
2286 /* now get back the chain */
2287 ic = iCodeLabelOptimize (iCodeFromeBBlock (ebbs, count));
2291 /* for (; ic ; ic = ic->next) */
2292 /* piCode(ic,stdout); */
2293 /* free up any _G.stackSpil locations allocated */
2294 applyToSet (_G.stackSpil, deallocStackSpil);
2296 setToNull ((void *) &_G.stackSpil);
2297 setToNull ((void *) &_G.spiltSet);
2298 /* mark all registers as free */