UserTy = LI->getType();
} else if (StoreInst *SI = dyn_cast<StoreInst>(UI->U->getUser())) {
UserTy = SI->getValueOperand()->getType();
- } else if (SelectInst *SI = dyn_cast<SelectInst>(UI->U->getUser())) {
- if (PointerType *PtrTy = dyn_cast<PointerType>(SI->getType()))
- UserTy = PtrTy->getElementType();
- } else if (PHINode *PN = dyn_cast<PHINode>(UI->U->getUser())) {
- if (PointerType *PtrTy = dyn_cast<PointerType>(PN->getType()))
- UserTy = PtrTy->getElementType();
}
if (Ty && Ty != UserTy)
static char ID;
private:
+ friend class PHIOrSelectSpeculator;
friend class AllocaPartitionRewriter;
friend class AllocaPartitionVectorRewriter;
}
namespace {
+/// \brief Visitor to speculate PHIs and Selects where possible.
+class PHIOrSelectSpeculator : public InstVisitor<PHIOrSelectSpeculator> {
+ // Befriend the base class so it can delegate to private visit methods.
+ friend class llvm::InstVisitor<PHIOrSelectSpeculator>;
+
+ const TargetData &TD;
+ AllocaPartitioning &P;
+ SROA &Pass;
+
+public:
+ PHIOrSelectSpeculator(const TargetData &TD, AllocaPartitioning &P, SROA &Pass)
+ : TD(TD), P(P), Pass(Pass) {}
+
+ /// \brief Visit the users of the alloca partition and rewrite them.
+ void visitUsers(AllocaPartitioning::const_use_iterator I,
+ AllocaPartitioning::const_use_iterator E) {
+ for (; I != E; ++I)
+ visit(cast<Instruction>(I->U->getUser()));
+ }
+
+private:
+ // By default, skip this instruction.
+ void visitInstruction(Instruction &I) {}
+
+ /// PHI instructions that use an alloca and are subsequently loaded can be
+ /// rewritten to load both input pointers in the pred blocks and then PHI the
+ /// results, allowing the load of the alloca to be promoted.
+ /// From this:
+ /// %P2 = phi [i32* %Alloca, i32* %Other]
+ /// %V = load i32* %P2
+ /// to:
+ /// %V1 = load i32* %Alloca -> will be mem2reg'd
+ /// ...
+ /// %V2 = load i32* %Other
+ /// ...
+ /// %V = phi [i32 %V1, i32 %V2]
+ ///
+ /// We can do this to a select if its only uses are loads and if the operand
+ /// to the select can be loaded unconditionally.
+ ///
+ /// FIXME: This should be hoisted into a generic utility, likely in
+ /// Transforms/Util/Local.h
+ bool isSafePHIToSpeculate(PHINode &PN, SmallVectorImpl<LoadInst *> &Loads) {
+ // For now, we can only do this promotion if the load is in the same block
+ // as the PHI, and if there are no stores between the phi and load.
+ // TODO: Allow recursive phi users.
+ // TODO: Allow stores.
+ BasicBlock *BB = PN.getParent();
+ unsigned MaxAlign = 0;
+ for (Value::use_iterator UI = PN.use_begin(), UE = PN.use_end();
+ UI != UE; ++UI) {
+ LoadInst *LI = dyn_cast<LoadInst>(*UI);
+ if (LI == 0 || !LI->isSimple()) return false;
+
+ // For now we only allow loads in the same block as the PHI. This is
+ // a common case that happens when instcombine merges two loads through
+ // a PHI.
+ if (LI->getParent() != BB) return false;
+
+ // Ensure that there are no instructions between the PHI and the load that
+ // could store.
+ for (BasicBlock::iterator BBI = &PN; &*BBI != LI; ++BBI)
+ if (BBI->mayWriteToMemory())
+ return false;
+
+ MaxAlign = std::max(MaxAlign, LI->getAlignment());
+ Loads.push_back(LI);
+ }
+
+ // We can only transform this if it is safe to push the loads into the
+ // predecessor blocks. The only thing to watch out for is that we can't put
+ // a possibly trapping load in the predecessor if it is a critical edge.
+ for (unsigned Idx = 0, Num = PN.getNumIncomingValues(); Idx != Num;
+ ++Idx) {
+ TerminatorInst *TI = PN.getIncomingBlock(Idx)->getTerminator();
+ Value *InVal = PN.getIncomingValue(Idx);
+
+ // If the value is produced by the terminator of the predecessor (an
+ // invoke) or it has side-effects, there is no valid place to put a load
+ // in the predecessor.
+ if (TI == InVal || TI->mayHaveSideEffects())
+ return false;
+
+ // If the predecessor has a single successor, then the edge isn't
+ // critical.
+ if (TI->getNumSuccessors() == 1)
+ continue;
+
+ // If this pointer is always safe to load, or if we can prove that there
+ // is already a load in the block, then we can move the load to the pred
+ // block.
+ if (InVal->isDereferenceablePointer() ||
+ isSafeToLoadUnconditionally(InVal, TI, MaxAlign, &TD))
+ continue;
+
+ return false;
+ }
+
+ return true;
+ }
+
+ void visitPHINode(PHINode &PN) {
+ DEBUG(dbgs() << " original: " << PN << "\n");
+
+ SmallVector<LoadInst *, 4> Loads;
+ if (!isSafePHIToSpeculate(PN, Loads))
+ return;
+
+ assert(!Loads.empty());
+
+ Type *LoadTy = cast<PointerType>(PN.getType())->getElementType();
+ IRBuilder<> PHIBuilder(&PN);
+ PHINode *NewPN = PHIBuilder.CreatePHI(LoadTy, PN.getNumIncomingValues(),
+ PN.getName() + ".sroa.speculated");
+
+ // Get the TBAA tag and alignment to use from one of the loads. It doesn't
+ // matter which one we get and if any differ, it doesn't matter.
+ LoadInst *SomeLoad = cast<LoadInst>(Loads.back());
+ MDNode *TBAATag = SomeLoad->getMetadata(LLVMContext::MD_tbaa);
+ unsigned Align = SomeLoad->getAlignment();
+
+ // Rewrite all loads of the PN to use the new PHI.
+ do {
+ LoadInst *LI = Loads.pop_back_val();
+ LI->replaceAllUsesWith(NewPN);
+ Pass.DeadInsts.push_back(LI);
+ } while (!Loads.empty());
+
+ // Inject loads into all of the pred blocks.
+ for (unsigned Idx = 0, Num = PN.getNumIncomingValues(); Idx != Num; ++Idx) {
+ BasicBlock *Pred = PN.getIncomingBlock(Idx);
+ TerminatorInst *TI = Pred->getTerminator();
+ Use *InUse = &PN.getOperandUse(PN.getOperandNumForIncomingValue(Idx));
+ Value *InVal = PN.getIncomingValue(Idx);
+ IRBuilder<> PredBuilder(TI);
+
+ LoadInst *Load
+ = PredBuilder.CreateLoad(InVal, (PN.getName() + ".sroa.speculate.load." +
+ Pred->getName()));
+ ++NumLoadsSpeculated;
+ Load->setAlignment(Align);
+ if (TBAATag)
+ Load->setMetadata(LLVMContext::MD_tbaa, TBAATag);
+ NewPN->addIncoming(Load, Pred);
+
+ Instruction *Ptr = dyn_cast<Instruction>(InVal);
+ if (!Ptr)
+ // No uses to rewrite.
+ continue;
+
+ // Try to lookup and rewrite any partition uses corresponding to this phi
+ // input.
+ AllocaPartitioning::iterator PI
+ = P.findPartitionForPHIOrSelectOperand(InUse);
+ if (PI == P.end())
+ continue;
+
+ // Replace the Use in the PartitionUse for this operand with the Use
+ // inside the load.
+ AllocaPartitioning::use_iterator UI
+ = P.findPartitionUseForPHIOrSelectOperand(InUse);
+ assert(isa<PHINode>(*UI->U->getUser()));
+ UI->U = &Load->getOperandUse(Load->getPointerOperandIndex());
+ }
+ DEBUG(dbgs() << " speculated to: " << *NewPN << "\n");
+ }
+
+ /// Select instructions that use an alloca and are subsequently loaded can be
+ /// rewritten to load both input pointers and then select between the result,
+ /// allowing the load of the alloca to be promoted.
+ /// From this:
+ /// %P2 = select i1 %cond, i32* %Alloca, i32* %Other
+ /// %V = load i32* %P2
+ /// to:
+ /// %V1 = load i32* %Alloca -> will be mem2reg'd
+ /// %V2 = load i32* %Other
+ /// %V = select i1 %cond, i32 %V1, i32 %V2
+ ///
+ /// We can do this to a select if its only uses are loads and if the operand
+ /// to the select can be loaded unconditionally.
+ bool isSafeSelectToSpeculate(SelectInst &SI,
+ SmallVectorImpl<LoadInst *> &Loads) {
+ Value *TValue = SI.getTrueValue();
+ Value *FValue = SI.getFalseValue();
+ bool TDerefable = TValue->isDereferenceablePointer();
+ bool FDerefable = FValue->isDereferenceablePointer();
+
+ for (Value::use_iterator UI = SI.use_begin(), UE = SI.use_end();
+ UI != UE; ++UI) {
+ LoadInst *LI = dyn_cast<LoadInst>(*UI);
+ if (LI == 0 || !LI->isSimple()) return false;
+
+ // Both operands to the select need to be dereferencable, either
+ // absolutely (e.g. allocas) or at this point because we can see other
+ // accesses to it.
+ if (!TDerefable && !isSafeToLoadUnconditionally(TValue, LI,
+ LI->getAlignment(), &TD))
+ return false;
+ if (!FDerefable && !isSafeToLoadUnconditionally(FValue, LI,
+ LI->getAlignment(), &TD))
+ return false;
+ Loads.push_back(LI);
+ }
+
+ return true;
+ }
+
+ void visitSelectInst(SelectInst &SI) {
+ DEBUG(dbgs() << " original: " << SI << "\n");
+ IRBuilder<> IRB(&SI);
+
+ // If the select isn't safe to speculate, just use simple logic to emit it.
+ SmallVector<LoadInst *, 4> Loads;
+ if (!isSafeSelectToSpeculate(SI, Loads))
+ return;
+
+ Use *Ops[2] = { &SI.getOperandUse(1), &SI.getOperandUse(2) };
+ AllocaPartitioning::iterator PIs[2];
+ AllocaPartitioning::PartitionUse PUs[2];
+ for (unsigned i = 0, e = 2; i != e; ++i) {
+ PIs[i] = P.findPartitionForPHIOrSelectOperand(Ops[i]);
+ if (PIs[i] != P.end()) {
+ // If the pointer is within the partitioning, remove the select from
+ // its uses. We'll add in the new loads below.
+ AllocaPartitioning::use_iterator UI
+ = P.findPartitionUseForPHIOrSelectOperand(Ops[i]);
+ PUs[i] = *UI;
+ P.use_erase(PIs[i], UI);
+ }
+ }
+
+ Value *TV = SI.getTrueValue();
+ Value *FV = SI.getFalseValue();
+ // Replace the loads of the select with a select of two loads.
+ while (!Loads.empty()) {
+ LoadInst *LI = Loads.pop_back_val();
+
+ IRB.SetInsertPoint(LI);
+ LoadInst *TL =
+ IRB.CreateLoad(TV, LI->getName() + ".sroa.speculate.load.true");
+ LoadInst *FL =
+ IRB.CreateLoad(FV, LI->getName() + ".sroa.speculate.load.false");
+ NumLoadsSpeculated += 2;
+
+ // Transfer alignment and TBAA info if present.
+ TL->setAlignment(LI->getAlignment());
+ FL->setAlignment(LI->getAlignment());
+ if (MDNode *Tag = LI->getMetadata(LLVMContext::MD_tbaa)) {
+ TL->setMetadata(LLVMContext::MD_tbaa, Tag);
+ FL->setMetadata(LLVMContext::MD_tbaa, Tag);
+ }
+
+ Value *V = IRB.CreateSelect(SI.getCondition(), TL, FL,
+ LI->getName() + ".sroa.speculated");
+
+ LoadInst *Loads[2] = { TL, FL };
+ for (unsigned i = 0, e = 2; i != e; ++i) {
+ if (PIs[i] != P.end()) {
+ Use *LoadUse = &Loads[i]->getOperandUse(0);
+ assert(PUs[i].U->get() == LoadUse->get());
+ PUs[i].U = LoadUse;
+ P.use_push_back(PIs[i], PUs[i]);
+ }
+ }
+
+ DEBUG(dbgs() << " speculated to: " << *V << "\n");
+ LI->replaceAllUsesWith(V);
+ Pass.DeadInsts.push_back(LI);
+ }
+ }
+};
+
/// \brief Visitor to rewrite instructions using a partition of an alloca to
/// use a new alloca.
///
return true;
}
- /// PHI instructions that use an alloca and are subsequently loaded can be
- /// rewritten to load both input pointers in the pred blocks and then PHI the
- /// results, allowing the load of the alloca to be promoted.
- /// From this:
- /// %P2 = phi [i32* %Alloca, i32* %Other]
- /// %V = load i32* %P2
- /// to:
- /// %V1 = load i32* %Alloca -> will be mem2reg'd
- /// ...
- /// %V2 = load i32* %Other
- /// ...
- /// %V = phi [i32 %V1, i32 %V2]
- ///
- /// We can do this to a select if its only uses are loads and if the operand
- /// to the select can be loaded unconditionally.
- ///
- /// FIXME: This should be hoisted into a generic utility, likely in
- /// Transforms/Util/Local.h
- bool isSafePHIToSpeculate(PHINode &PN, SmallVectorImpl<LoadInst *> &Loads) {
- // For now, we can only do this promotion if the load is in the same block
- // as the PHI, and if there are no stores between the phi and load.
- // TODO: Allow recursive phi users.
- // TODO: Allow stores.
- BasicBlock *BB = PN.getParent();
- unsigned MaxAlign = 0;
- for (Value::use_iterator UI = PN.use_begin(), UE = PN.use_end();
- UI != UE; ++UI) {
- LoadInst *LI = dyn_cast<LoadInst>(*UI);
- if (LI == 0 || !LI->isSimple()) return false;
-
- // For now we only allow loads in the same block as the PHI. This is
- // a common case that happens when instcombine merges two loads through
- // a PHI.
- if (LI->getParent() != BB) return false;
-
- // Ensure that there are no instructions between the PHI and the load that
- // could store.
- for (BasicBlock::iterator BBI = &PN; &*BBI != LI; ++BBI)
- if (BBI->mayWriteToMemory())
- return false;
-
- MaxAlign = std::max(MaxAlign, LI->getAlignment());
- Loads.push_back(LI);
- }
-
- // We can only transform this if it is safe to push the loads into the
- // predecessor blocks. The only thing to watch out for is that we can't put
- // a possibly trapping load in the predecessor if it is a critical edge.
- for (unsigned Idx = 0, Num = PN.getNumIncomingValues(); Idx != Num;
- ++Idx) {
- TerminatorInst *TI = PN.getIncomingBlock(Idx)->getTerminator();
- Value *InVal = PN.getIncomingValue(Idx);
-
- // If the value is produced by the terminator of the predecessor (an
- // invoke) or it has side-effects, there is no valid place to put a load
- // in the predecessor.
- if (TI == InVal || TI->mayHaveSideEffects())
- return false;
-
- // If the predecessor has a single successor, then the edge isn't
- // critical.
- if (TI->getNumSuccessors() == 1)
- continue;
-
- // If this pointer is always safe to load, or if we can prove that there
- // is already a load in the block, then we can move the load to the pred
- // block.
- if (InVal->isDereferenceablePointer() ||
- isSafeToLoadUnconditionally(InVal, TI, MaxAlign, &TD))
- continue;
-
- return false;
- }
-
- return true;
- }
-
bool visitPHINode(PHINode &PN) {
DEBUG(dbgs() << " original: " << PN << "\n");
+
// We would like to compute a new pointer in only one place, but have it be
// as local as possible to the PHI. To do that, we re-use the location of
// the old pointer, which necessarily must be in the right position to
// dominate the PHI.
IRBuilder<> PtrBuilder(cast<Instruction>(OldPtr));
- SmallVector<LoadInst *, 4> Loads;
- if (!isSafePHIToSpeculate(PN, Loads)) {
- Value *NewPtr = getAdjustedAllocaPtr(PtrBuilder, OldPtr->getType());
- // Replace the operands which were using the old pointer.
- User::op_iterator OI = PN.op_begin(), OE = PN.op_end();
- for (; OI != OE; ++OI)
- if (*OI == OldPtr)
- *OI = NewPtr;
-
- DEBUG(dbgs() << " to: " << PN << "\n");
- deleteIfTriviallyDead(OldPtr);
- return false;
- }
- assert(!Loads.empty());
-
- Type *LoadTy = cast<PointerType>(PN.getType())->getElementType();
- IRBuilder<> PHIBuilder(&PN);
- PHINode *NewPN = PHIBuilder.CreatePHI(LoadTy, PN.getNumIncomingValues());
- NewPN->takeName(&PN);
-
- // Get the TBAA tag and alignment to use from one of the loads. It doesn't
- // matter which one we get and if any differ, it doesn't matter.
- LoadInst *SomeLoad = cast<LoadInst>(Loads.back());
- MDNode *TBAATag = SomeLoad->getMetadata(LLVMContext::MD_tbaa);
- unsigned Align = SomeLoad->getAlignment();
Value *NewPtr = getAdjustedAllocaPtr(PtrBuilder, OldPtr->getType());
+ // Replace the operands which were using the old pointer.
+ User::op_iterator OI = PN.op_begin(), OE = PN.op_end();
+ for (; OI != OE; ++OI)
+ if (*OI == OldPtr)
+ *OI = NewPtr;
- // Rewrite all loads of the PN to use the new PHI.
- do {
- LoadInst *LI = Loads.pop_back_val();
- LI->replaceAllUsesWith(NewPN);
- Pass.DeadInsts.push_back(LI);
- } while (!Loads.empty());
-
- // Inject loads into all of the pred blocks.
- for (unsigned Idx = 0, Num = PN.getNumIncomingValues(); Idx != Num; ++Idx) {
- BasicBlock *Pred = PN.getIncomingBlock(Idx);
- TerminatorInst *TI = Pred->getTerminator();
- Value *InVal = PN.getIncomingValue(Idx);
- IRBuilder<> PredBuilder(TI);
-
- // Map the value to the new alloca pointer if this was the old alloca
- // pointer.
- Use *InUse = &PN.getOperandUse(PN.getOperandNumForIncomingValue(Idx));
- bool ThisOperand = InUse == OldUse;
- if (ThisOperand)
- InVal = NewPtr;
-
- LoadInst *Load
- = PredBuilder.CreateLoad(InVal, getName(".sroa.speculate." +
- Pred->getName()));
- ++NumLoadsSpeculated;
- Load->setAlignment(Align);
- if (TBAATag)
- Load->setMetadata(LLVMContext::MD_tbaa, TBAATag);
- NewPN->addIncoming(Load, Pred);
-
- Instruction *Ptr = dyn_cast<Instruction>(InVal);
- if (!Ptr)
- // No uses to rewrite.
- continue;
-
- // Try to lookup and rewrite any partition uses corresponding to this phi
- // input.
- AllocaPartitioning::iterator PI
- = P.findPartitionForPHIOrSelectOperand(InUse);
- if (PI == P.end())
- continue;
-
- // Replace the Use in the PartitionUse for this operand with the Use
- // inside the load. This will already have been re-written for the
- // partition use currently being processed.
- // FIXME: This is really gross. We should do PHI and select speculation
- // as a pre-processing pass first, and then use the existing
- // load-rewriting logic.
- AllocaPartitioning::use_iterator UI
- = P.findPartitionUseForPHIOrSelectOperand(InUse);
- assert(isa<PHINode>(*UI->U->getUser()));
- UI->U = &Load->getOperandUse(Load->getPointerOperandIndex());
- }
- DEBUG(dbgs() << " speculated to: " << *NewPN << "\n");
- return NewPtr == &NewAI;
- }
-
- /// Select instructions that use an alloca and are subsequently loaded can be
- /// rewritten to load both input pointers and then select between the result,
- /// allowing the load of the alloca to be promoted.
- /// From this:
- /// %P2 = select i1 %cond, i32* %Alloca, i32* %Other
- /// %V = load i32* %P2
- /// to:
- /// %V1 = load i32* %Alloca -> will be mem2reg'd
- /// %V2 = load i32* %Other
- /// %V = select i1 %cond, i32 %V1, i32 %V2
- ///
- /// We can do this to a select if its only uses are loads and if the operand
- /// to the select can be loaded unconditionally.
- bool isSafeSelectToSpeculate(SelectInst &SI,
- SmallVectorImpl<LoadInst *> &Loads) {
- Value *TValue = SI.getTrueValue();
- Value *FValue = SI.getFalseValue();
- bool TDerefable = TValue->isDereferenceablePointer();
- bool FDerefable = FValue->isDereferenceablePointer();
-
- for (Value::use_iterator UI = SI.use_begin(), UE = SI.use_end();
- UI != UE; ++UI) {
- LoadInst *LI = dyn_cast<LoadInst>(*UI);
- if (LI == 0 || !LI->isSimple()) return false;
-
- // Both operands to the select need to be dereferencable, either
- // absolutely (e.g. allocas) or at this point because we can see other
- // accesses to it.
- if (!TDerefable && !isSafeToLoadUnconditionally(TValue, LI,
- LI->getAlignment(), &TD))
- return false;
- if (!FDerefable && !isSafeToLoadUnconditionally(FValue, LI,
- LI->getAlignment(), &TD))
- return false;
- Loads.push_back(LI);
- }
-
- return true;
+ DEBUG(dbgs() << " to: " << PN << "\n");
+ deleteIfTriviallyDead(OldPtr);
+ return false;
}
bool visitSelectInst(SelectInst &SI) {
assert(SI.getFalseValue() != OldPtr && "Pointer is both operands!");
else
assert(SI.getFalseValue() == OldPtr && "Pointer isn't an operand!");
- Value *NewPtr = getAdjustedAllocaPtr(IRB, OldPtr->getType());
-
- // If the select isn't safe to speculate, just use simple logic to emit it.
- SmallVector<LoadInst *, 4> Loads;
- if (!isSafeSelectToSpeculate(SI, Loads)) {
- SI.setOperand(IsTrueVal ? 1 : 2, NewPtr);
- DEBUG(dbgs() << " to: " << SI << "\n");
- deleteIfTriviallyDead(OldPtr);
- return false;
- }
-
- Use *OtherOp = &SI.getOperandUse(IsTrueVal ? 2 : 1);
- AllocaPartitioning::iterator PI
- = P.findPartitionForPHIOrSelectOperand(OtherOp);
- AllocaPartitioning::PartitionUse OtherUse;
- if (PI != P.end()) {
- // If the other pointer is within the partitioning, remove the select
- // from its uses. We'll add in the new loads below.
- AllocaPartitioning::use_iterator UI
- = P.findPartitionUseForPHIOrSelectOperand(OtherOp);
- OtherUse = *UI;
- P.use_erase(PI, UI);
- }
-
- Value *TV = IsTrueVal ? NewPtr : SI.getTrueValue();
- Value *FV = IsTrueVal ? SI.getFalseValue() : NewPtr;
- // Replace the loads of the select with a select of two loads.
- while (!Loads.empty()) {
- LoadInst *LI = Loads.pop_back_val();
-
- IRB.SetInsertPoint(LI);
- LoadInst *TL =
- IRB.CreateLoad(TV, getName("." + LI->getName() + ".true"));
- LoadInst *FL =
- IRB.CreateLoad(FV, getName("." + LI->getName() + ".false"));
- NumLoadsSpeculated += 2;
-
- // Transfer alignment and TBAA info if present.
- TL->setAlignment(LI->getAlignment());
- FL->setAlignment(LI->getAlignment());
- if (MDNode *Tag = LI->getMetadata(LLVMContext::MD_tbaa)) {
- TL->setMetadata(LLVMContext::MD_tbaa, Tag);
- FL->setMetadata(LLVMContext::MD_tbaa, Tag);
- }
-
- SelectInst *NewSI
- = cast<SelectInst>(IRB.CreateSelect(SI.getCondition(), TL, FL));
- NewSI->takeName(LI);
- if (PI != P.end()) {
- LoadInst *OtherLoad = IsTrueVal ? FL : TL;
- Use *OtherLoadUse = &OtherLoad->getOperandUse(0);
- assert(OtherUse.U->get() == OtherLoadUse->get());
- OtherUse.U = OtherLoadUse;
- P.use_push_back(PI, OtherUse);
- }
- DEBUG(dbgs() << " speculated to: " << *NewSI << "\n");
- LI->replaceAllUsesWith(NewSI);
- Pass.DeadInsts.push_back(LI);
- }
+ Value *NewPtr = getAdjustedAllocaPtr(IRB, OldPtr->getType());
+ SI.setOperand(IsTrueVal ? 1 : 2, NewPtr);
+ DEBUG(dbgs() << " to: " << SI << "\n");
deleteIfTriviallyDead(OldPtr);
- return NewPtr == &NewAI;
+ return false;
}
};
if (P.use_begin(PI) == P.use_end(PI))
return false; // No live uses left of this partition.
+ DEBUG(dbgs() << "Speculating PHIs and selects in partition "
+ << "[" << PI->BeginOffset << "," << PI->EndOffset << ")\n");
+
+ PHIOrSelectSpeculator Speculator(*TD, P, *this);
+ DEBUG(dbgs() << " speculating ");
+ DEBUG(P.print(dbgs(), PI, ""));
+ Speculator.visitUsers(P.use_begin(PI), P.use_end(PI));
+
// Try to compute a friendly type for this partition of the alloca. This
// won't always succeed, in which case we fall back to a legal integer type
// or an i8 array of an appropriate size.