- {
-
- /* if this is an ipop that means some live
- range will have to be assigned again */
- if (ic->op == IPOP)
- reassignLR (IC_LEFT (ic));
-
- /* if result is present && is a true symbol */
- if (IC_RESULT (ic) && ic->op != IFX &&
- IS_TRUE_SYMOP (IC_RESULT (ic)))
- OP_SYMBOL (IC_RESULT (ic))->allocreq = 1;
-
- /* take away registers from live
- ranges that end at this instruction */
- deassignLRs (ic, ebbs[i]);
-
- /* some don't need registers */
- if (SKIP_IC2 (ic) ||
- ic->op == JUMPTABLE ||
- ic->op == IFX ||
- ic->op == IPUSH ||
- ic->op == IPOP ||
- (IC_RESULT (ic) && POINTER_SET (ic)))
- continue;
-
- /* now we need to allocate registers
- only for the result */
- if (IC_RESULT (ic))
- {
- symbol *sym = OP_SYMBOL (IC_RESULT (ic));
- bitVect *spillable;
- int willCS;
- int j;
- int ptrRegSet = 0;
-
- /* if it does not need or is spilt
- or is already assigned to registers
- or will not live beyond this instructions */
- if (!sym->nRegs ||
- sym->isspilt ||
- bitVectBitValue (_G.regAssigned, sym->key) ||
- sym->liveTo <= ic->seq)
- continue;
-
- /* if some liverange has been spilt at the block level
- and this one live beyond this block then spil this
- to be safe */
- if (_G.blockSpil && sym->liveTo > ebbs[i]->lSeq)
- {
- spillThis (sym);
- continue;
- }
- /* if trying to allocate this will cause
- a spill and there is nothing to spill
- or this one is rematerializable then
- spill this one */
- willCS = willCauseSpill (sym->nRegs, sym->regType);
- spillable = computeSpillable (ic);
- if (sym->remat ||
- (willCS && bitVectIsZero (spillable)))
- {
-
- spillThis (sym);
- continue;
-
- }
-
- /* if it has a spillocation & is used less than
- all other live ranges then spill this */
- if (willCS) {
- if (sym->usl.spillLoc) {
- symbol *leastUsed = leastUsedLR (liveRangesWith (spillable,
- allLRs, ebbs[i], ic));
- if (leastUsed && leastUsed->used > sym->used) {
- spillThis (sym);
- continue;
- }
- } else {
- /* if none of the liveRanges have a spillLocation then better
- to spill this one than anything else already assigned to registers */
- if (liveRangesWith(spillable,noSpilLoc,ebbs[i],ic)) {
- spillThis (sym);
- continue;
- }
- }
- }
-
- /* if we need ptr regs for the right side
- then mark it */
- if (POINTER_GET (ic) && IS_SYMOP (IC_LEFT (ic))
- && getSize (OP_SYMBOL (IC_LEFT (ic))->type)
- <= (unsigned) PTRSIZE)
- {
- ds390_ptrRegReq++;
- ptrRegSet = 1;
- }
- /* else we assign registers to it */
- _G.regAssigned = bitVectSetBit (_G.regAssigned, sym->key);
-
- for (j = 0; j < sym->nRegs; j++)
- {
- if (sym->regType == REG_PTR)
- sym->regs[j] = getRegPtr (ic, ebbs[i], sym);
- else
- sym->regs[j] = getRegGpr (ic, ebbs[i], sym);
-
- /* if the allocation falied which means
- this was spilt then break */
- if (!sym->regs[j])
- break;
- }
- /* if it shares registers with operands make sure
- that they are in the same position */
- if (IC_LEFT (ic) && IS_SYMOP (IC_LEFT (ic)) &&
- OP_SYMBOL (IC_LEFT (ic))->nRegs && ic->op != '=')
- positionRegs (OP_SYMBOL (IC_RESULT (ic)),
- OP_SYMBOL (IC_LEFT (ic)), ic->lineno);
- /* do the same for the right operand */
- if (IC_RIGHT (ic) && IS_SYMOP (IC_RIGHT (ic)) &&
- OP_SYMBOL (IC_RIGHT (ic))->nRegs)
- positionRegs (OP_SYMBOL (IC_RESULT (ic)),
- OP_SYMBOL (IC_RIGHT (ic)), ic->lineno);
-
- if (ptrRegSet)
- {
- ds390_ptrRegReq--;
- ptrRegSet = 0;
- }
-
- }
- }
+ {
+
+ /* if this is an ipop that means some live
+ range will have to be assigned again */
+ if (ic->op == IPOP)
+ reassignLR (IC_LEFT (ic));
+
+ /* if result is present && is a true symbol */
+ if (IC_RESULT (ic) && ic->op != IFX &&
+ IS_TRUE_SYMOP (IC_RESULT (ic)))
+ OP_SYMBOL (IC_RESULT (ic))->allocreq++;
+
+ /* take away registers from live
+ ranges that end at this instruction */
+ deassignLRs (ic, ebbs[i]);
+
+ /* some don't need registers */
+ if (SKIP_IC2 (ic) ||
+ ic->op == JUMPTABLE ||
+ ic->op == IFX ||
+ ic->op == IPUSH ||
+ ic->op == IPOP ||
+ (IC_RESULT (ic) && POINTER_SET (ic)))
+ continue;
+
+ /* now we need to allocate registers
+ only for the result */
+ if (IC_RESULT (ic))
+ {
+ symbol *sym = OP_SYMBOL (IC_RESULT (ic));
+ bitVect *spillable;
+ int willCS;
+ int j;
+ int ptrRegSet = 0;
+
+ /* Make sure any spill location is definately allocated */
+ if (sym->isspilt && !sym->remat && sym->usl.spillLoc &&
+ !sym->usl.spillLoc->allocreq)
+ {
+ sym->usl.spillLoc->allocreq++;
+ }
+
+ /* if it does not need or is spilt
+ or is already assigned to registers
+ or will not live beyond this instructions */
+ if (!sym->nRegs ||
+ sym->isspilt ||
+ bitVectBitValue (_G.regAssigned, sym->key) ||
+ sym->liveTo <= ic->seq)
+ continue;
+
+ /* if some liverange has been spilt at the block level
+ and this one live beyond this block then spil this
+ to be safe */
+ if (_G.blockSpil && sym->liveTo > ebbs[i]->lSeq)
+ {
+ spillThis (sym);
+ continue;
+ }
+
+ /* if this is a bit variable then don't use precious registers
+ along with expensive bit-to-char conversions but just spill
+ it */
+ if (SPEC_NOUN(sym->etype) == V_BIT)
+ {
+ spillThis (sym);
+ continue;
+ }
+
+ /* if trying to allocate this will cause
+ a spill and there is nothing to spill
+ or this one is rematerializable then
+ spill this one */
+ willCS = willCauseSpill (sym->nRegs, sym->regType);
+ spillable = computeSpillable (ic);
+ if (sym->remat ||
+ (willCS && bitVectIsZero (spillable)))
+ {
+
+ spillThis (sym);
+ continue;
+
+ }
+
+ /* If the live range preceeds the point of definition
+ then ideally we must take into account registers that
+ have been allocated after sym->liveFrom but freed
+ before ic->seq. This is complicated, so spill this
+ symbol instead and let fillGaps handle the allocation. */
+ if (sym->liveFrom < ic->seq)
+ {
+ spillThis (sym);
+ continue;
+ }
+
+ /* if it has a spillocation & is used less than
+ all other live ranges then spill this */
+ if (willCS) {
+ if (sym->usl.spillLoc) {
+ symbol *leastUsed = leastUsedLR (liveRangesWith (spillable,
+ allLRs, ebbs[i], ic));
+ if (leastUsed && leastUsed->used > sym->used) {
+ spillThis (sym);
+ continue;
+ }
+ } else {
+ /* if none of the liveRanges have a spillLocation then better
+ to spill this one than anything else already assigned to registers */
+ if (liveRangesWith(spillable,noSpilLoc,ebbs[i],ic)) {
+ /* if this is local to this block then we might find a block spil */
+ if (!(sym->liveFrom >= ebbs[i]->fSeq && sym->liveTo <= ebbs[i]->lSeq)) {
+ spillThis (sym);
+ continue;
+ }
+ }
+ }
+ }
+
+ /* if we need ptr regs for the right side
+ then mark it */
+ if (POINTER_GET (ic) && IS_SYMOP (IC_LEFT (ic))
+ && getSize (OP_SYMBOL (IC_LEFT (ic))->type)
+ <= (unsigned) PTRSIZE)
+ {
+ ds390_ptrRegReq++;
+ ptrRegSet = 1;
+ }
+ /* else we assign registers to it */
+ _G.regAssigned = bitVectSetBit (_G.regAssigned, sym->key);
+ _G.totRegAssigned = bitVectSetBit (_G.totRegAssigned, sym->key);
+
+ for (j = 0; j < sym->nRegs; j++)
+ {
+ if (sym->regType == REG_PTR)
+ sym->regs[j] = getRegPtr (ic, ebbs[i], sym);
+ else
+ sym->regs[j] = getRegGpr (ic, ebbs[i], sym);
+
+ /* if the allocation falied which means
+ this was spilt then break */
+ if (!sym->regs[j])
+ break;
+ }
+
+ /* if it shares registers with operands make sure
+ that they are in the same position */
+ if (!POINTER_SET(ic) && !POINTER_GET(ic))
+ {
+ if (IC_LEFT (ic) && IS_SYMOP (IC_LEFT (ic)) &&
+ OP_SYMBOL (IC_LEFT (ic))->nRegs)
+ {
+ positionRegs (OP_SYMBOL (IC_RESULT (ic)),
+ OP_SYMBOL (IC_LEFT (ic)));
+ }
+ /* do the same for the right operand */
+ if (IC_RIGHT (ic) && IS_SYMOP (IC_RIGHT (ic)) &&
+ OP_SYMBOL (IC_RIGHT (ic))->nRegs)
+ {
+ positionRegs (OP_SYMBOL (IC_RESULT (ic)),
+ OP_SYMBOL (IC_RIGHT (ic)));
+ }
+ }
+
+ if (ptrRegSet)
+ {
+ ds390_ptrRegReq--;
+ ptrRegSet = 0;
+ }
+
+ }
+ }
+ reassignUnusedLRs(unusedLRs);
+ }
+
+ /* Check for and fix any problems with uninitialized operands */
+ for (i = 0; i < count; i++)
+ {
+ iCode *ic;
+
+ if (ebbs[i]->noPath &&
+ (ebbs[i]->entryLabel != entryLabel &&
+ ebbs[i]->entryLabel != returnLabel))
+ continue;
+
+ for (ic = ebbs[i]->sch; ic; ic = ic->next)
+ {
+ if (SKIP_IC2 (ic))
+ continue;
+
+ if (ic->op == IFX)
+ {
+ verifyRegsAssigned (IC_COND (ic), ic);
+ continue;
+ }
+
+ if (ic->op == JUMPTABLE)
+ {
+ verifyRegsAssigned (IC_JTCOND (ic), ic);
+ continue;
+ }
+
+ verifyRegsAssigned (IC_RESULT (ic), ic);
+ verifyRegsAssigned (IC_LEFT (ic), ic);
+ verifyRegsAssigned (IC_RIGHT (ic), ic);
+ }
+ }
+}
+
+/*-----------------------------------------------------------------*/
+/* fillGaps - Try to fill in the Gaps left by Pass1 */
+/*-----------------------------------------------------------------*/
+static void fillGaps()
+{
+ symbol *sym =NULL;
+ int key =0;
+ int loop = 0, change;
+ int pass;
+
+ if (getenv("DISABLE_FILL_GAPS")) return;
+
+ /* First try to do DPTRuse once more since now we know what got into
+ registers */
+
+ while (loop++ < 10) {
+ change = 0;
+
+ for (sym = hTabFirstItem(liveRanges,&key) ; sym ;
+ sym = hTabNextItem(liveRanges,&key)) {
+ int size = getSize(sym->type);
+
+ if (sym->liveFrom == sym->liveTo) continue;
+
+ if (sym->uptr && sym->dptr==0 && !sym->ruonly &&
+ size < 4 && size > 1) {
+
+ if (packRegsDPTRuse(operandFromSymbol(sym))) {
+
+ /* if this was assigned to registers then */
+ if (bitVectBitValue(_G.totRegAssigned,sym->key)) {
+ /* take it out of the register assigned set */
+ bitVectUnSetBit(_G.totRegAssigned,sym->key);
+ } else if (sym->usl.spillLoc) {
+ sym->usl.spillLoc->allocreq--;
+ sym->usl.spillLoc = NULL;
+ }
+
+ sym->nRegs = 0;
+ sym->isspilt = sym->spillA = 0;
+ continue ;
+ }
+
+ /* try assigning other dptrs */
+ if (sym->dptr == 0 && packRegsDPTRnuse(operandFromSymbol(sym),1) && !getenv("DPTRnDISABLE")) {
+ /* if this was ssigned to registers then */
+ if (bitVectBitValue(_G.totRegAssigned,sym->key)) {
+ /* take it out of the register assigned set */
+ bitVectUnSetBit(_G.totRegAssigned,sym->key);
+ } else if (sym->usl.spillLoc) {
+ sym->usl.spillLoc->allocreq--;
+ sym->usl.spillLoc = NULL;
+ }
+ sym->nRegs = 0;
+ sym->isspilt = sym->spillA = 0;
+ }
+ }
+ }
+
+ /* look for livernages that was spilt by the allocator */
+ for (sym = hTabFirstItem(liveRanges,&key) ; sym ;
+ sym = hTabNextItem(liveRanges,&key)) {
+
+ int i;
+ int pdone = 0;
+
+ if (!sym->spillA || !sym->clashes || sym->remat) continue ;
+ if (!sym->uses || !sym->defs) continue ;
+ /* find the liveRanges this one clashes with, that are
+ still assigned to registers & mark the registers as used*/
+ for ( i = 0 ; i < sym->clashes->size ; i ++) {
+ int k;
+ symbol *clr;
+
+ if (bitVectBitValue(sym->clashes,i) == 0 || /* those that clash with this */
+ bitVectBitValue(_G.totRegAssigned,i) == 0) /* and are still assigned to registers */
+ continue ;
+
+ clr = hTabItemWithKey(liveRanges,i);
+ assert(clr);
+
+ /* mark these registers as used */
+ for (k = 0 ; k < clr->nRegs ; k++ )
+ useReg(clr->regs[k]);
+ }
+
+ if (willCauseSpill(sym->nRegs,sym->regType)) {
+ /* NOPE :( clear all registers & and continue */
+ freeAllRegs();
+ continue ;
+ }
+
+ /* THERE IS HOPE !!!! */
+ for (i=0; i < sym->nRegs ; i++ ) {
+ if (sym->regType == REG_PTR)
+ sym->regs[i] = getRegPtrNoSpil ();
+ else
+ sym->regs[i] = getRegGprNoSpil ();
+ }
+
+ /* For all its definitions check if the registers
+ allocated needs positioning NOTE: we can position
+ only ONCE if more than One positioning required
+ then give up.
+ We may need to perform the checks twice; once to
+ position the registers as needed, the second to
+ verify any register repositioning is still
+ compatible.
+ */
+ sym->isspilt = 0;
+ for (pass=0; pass<2; pass++) {
+ for (i = 0 ; i < sym->defs->size ; i++ ) {
+ if (bitVectBitValue(sym->defs,i)) {
+ iCode *ic;
+ if (!(ic = hTabItemWithKey(iCodehTab,i))) continue ;
+ if (SKIP_IC(ic)) continue;
+ assert(isSymbolEqual(sym,OP_SYMBOL(IC_RESULT(ic)))); /* just making sure */
+ /* if left is assigned to registers */
+ if (IS_SYMOP(IC_LEFT(ic)) &&
+ bitVectBitValue(_G.totRegAssigned,OP_SYMBOL(IC_LEFT(ic))->key)) {
+ pdone += (positionRegs(sym,OP_SYMBOL(IC_LEFT(ic)))>0);
+ }
+ if (IS_SYMOP(IC_RIGHT(ic)) &&
+ bitVectBitValue(_G.totRegAssigned,OP_SYMBOL(IC_RIGHT(ic))->key)) {
+ pdone += (positionRegs(sym,OP_SYMBOL(IC_RIGHT(ic)))>0);
+ }
+ if (pdone > 1) break;
+ }
+ }
+ for (i = 0 ; i < sym->uses->size ; i++ ) {
+ if (bitVectBitValue(sym->uses,i)) {
+ iCode *ic;
+ if (!(ic = hTabItemWithKey(iCodehTab,i))) continue ;
+ if (SKIP_IC(ic)) continue;
+ if (POINTER_SET(ic) || POINTER_GET(ic)) continue ;
+
+ /* if result is assigned to registers */
+ if (IS_SYMOP(IC_RESULT(ic)) &&
+ bitVectBitValue(_G.totRegAssigned,OP_SYMBOL(IC_RESULT(ic))->key)) {
+ pdone += (positionRegs(sym,OP_SYMBOL(IC_RESULT(ic)))>0);
+ }
+ if (pdone > 1) break;
+ }
+ }
+ if (pdone == 0) break; /* second pass only if regs repositioned */
+ if (pdone > 1) break;
+ }
+ /* had to position more than once GIVE UP */
+ if (pdone > 1) {
+ /* UNDO all the changes we made to try this */
+ sym->isspilt = 1;
+ for (i=0; i < sym->nRegs ; i++ ) {
+ sym->regs[i] = NULL;
+ }
+ freeAllRegs();
+ D (fprintf (stderr, "Fill Gap gave up due to positioning for "
+ "%s in function %s\n",
+ sym->name, currFunc ? currFunc->name : "UNKNOWN"));
+ continue ;
+ }
+ D (fprintf (stderr, "FILLED GAP for %s in function %s\n",
+ sym->name, currFunc ? currFunc->name : "UNKNOWN"));
+ _G.totRegAssigned = bitVectSetBit(_G.totRegAssigned,sym->key);
+ sym->isspilt = sym->spillA = 0 ;
+ sym->usl.spillLoc->allocreq--;
+ sym->usl.spillLoc = NULL;
+ freeAllRegs();
+ change ++;
+ }
+ if (!change) break;