/// The bounds of these uses are determined by intersecting the bounds of the
/// memory use itself with a particular partition. As a consequence there is
/// intentionally overlap between various uses of the same partition.
- struct PartitionUse : public ByteRange {
+ class PartitionUse : public ByteRange {
+ /// \brief Combined storage for both the Use* and split state.
+ PointerIntPair<Use*, 1, bool> UsePtrAndIsSplit;
+
+ public:
+ PartitionUse() : ByteRange(), UsePtrAndIsSplit() {}
+ PartitionUse(uint64_t BeginOffset, uint64_t EndOffset, Use *U,
+ bool IsSplit)
+ : ByteRange(BeginOffset, EndOffset), UsePtrAndIsSplit(U, IsSplit) {}
+
/// \brief The use in question. Provides access to both user and used value.
///
/// Note that this may be null if the partition use is *dead*, that is, it
/// should be ignored.
- Use *U;
+ Use *getUse() const { return UsePtrAndIsSplit.getPointer(); }
+
+ /// \brief Set the use for this partition use range.
+ void setUse(Use *U) { UsePtrAndIsSplit.setPointer(U); }
- PartitionUse() : ByteRange(), U() {}
- PartitionUse(uint64_t BeginOffset, uint64_t EndOffset, Use *U)
- : ByteRange(BeginOffset, EndOffset), U(U) {}
+ /// \brief Whether this use is split across multiple partitions.
+ bool isSplit() const { return UsePtrAndIsSplit.getInt(); }
};
/// \brief Construct a partitioning of a particular alloca.
// Clamp the end offset to the end of the allocation. Note that this is
// formulated to handle even the case where "BeginOffset + Size" overflows.
- // NOTE! This may appear superficially to be something we could ignore
- // entirely, but that is not so! There may be PHI-node uses where some
- // instructions are dead but not others. We can't completely ignore the
- // PHI node, and so have to record at least the information here.
+ // This may appear superficially to be something we could ignore entirely,
+ // but that is not so! There may be widened loads or PHI-node uses where
+ // some instructions are dead but not others. We can't completely ignore
+ // them, and so have to record at least the information here.
assert(AllocSize >= BeginOffset); // Established above.
if (Size > AllocSize - BeginOffset) {
DEBUG(dbgs() << "WARNING: Clamping a " << Size << " byte use @" << Offset
}
void handleLoadOrStore(Type *Ty, Instruction &I, const APInt &Offset,
- bool IsVolatile) {
- uint64_t Size = DL.getTypeStoreSize(Ty);
-
- // If this memory access can be shown to *statically* extend outside the
- // bounds of of the allocation, it's behavior is undefined, so simply
- // ignore it. Note that this is more strict than the generic clamping
- // behavior of insertUse. We also try to handle cases which might run the
- // risk of overflow.
- // FIXME: We should instead consider the pointer to have escaped if this
- // function is being instrumented for addressing bugs or race conditions.
- if (Offset.isNegative() || Size > AllocSize ||
- Offset.ugt(AllocSize - Size)) {
- DEBUG(dbgs() << "WARNING: Ignoring " << Size << " byte "
- << (isa<LoadInst>(I) ? "load" : "store") << " @" << Offset
- << " which extends past the end of the " << AllocSize
- << " byte alloca:\n"
- << " alloca: " << P.AI << "\n"
- << " use: " << I << "\n");
- return;
- }
-
+ uint64_t Size, bool IsVolatile) {
// We allow splitting of loads and stores where the type is an integer type
- // and which cover the entire alloca. Such integer loads and stores
- // often require decomposition into fine grained loads and stores.
- bool IsSplittable = false;
- if (IntegerType *ITy = dyn_cast<IntegerType>(Ty))
- IsSplittable = !IsVolatile && ITy->getBitWidth() == AllocSize*8;
+ // and cover the entire alloca. This prevents us from splitting over
+ // eagerly.
+ // FIXME: In the great blue eventually, we should eagerly split all integer
+ // loads and stores, and then have a separate step that merges adjacent
+ // alloca partitions into a single partition suitable for integer widening.
+ // Or we should skip the merge step and rely on GVN and other passes to
+ // merge adjacent loads and stores that survive mem2reg.
+ bool IsSplittable =
+ Ty->isIntegerTy() && !IsVolatile && Offset == 0 && Size >= AllocSize;
insertUse(I, Offset, Size, IsSplittable);
}
if (!IsOffsetKnown)
return PI.setAborted(&LI);
- return handleLoadOrStore(LI.getType(), LI, Offset, LI.isVolatile());
+ uint64_t Size = DL.getTypeStoreSize(LI.getType());
+ return handleLoadOrStore(LI.getType(), LI, Offset, Size, LI.isVolatile());
}
void visitStoreInst(StoreInst &SI) {
if (!IsOffsetKnown)
return PI.setAborted(&SI);
+ uint64_t Size = DL.getTypeStoreSize(ValOp->getType());
+
+ // If this memory access can be shown to *statically* extend outside the
+ // bounds of of the allocation, it's behavior is undefined, so simply
+ // ignore it. Note that this is more strict than the generic clamping
+ // behavior of insertUse. We also try to handle cases which might run the
+ // risk of overflow.
+ // FIXME: We should instead consider the pointer to have escaped if this
+ // function is being instrumented for addressing bugs or race conditions.
+ if (Offset.isNegative() || Size > AllocSize ||
+ Offset.ugt(AllocSize - Size)) {
+ DEBUG(dbgs() << "WARNING: Ignoring " << Size << " byte store @" << Offset
+ << " which extends past the end of the " << AllocSize
+ << " byte alloca:\n"
+ << " alloca: " << P.AI << "\n"
+ << " use: " << SI << "\n");
+ return;
+ }
+
assert((!SI.isSimple() || ValOp->getType()->isSingleValueType()) &&
"All simple FCA stores should have been pre-split");
- handleLoadOrStore(ValOp->getType(), SI, Offset, SI.isVolatile());
+ handleLoadOrStore(ValOp->getType(), SI, Offset, Size, SI.isVolatile());
}
EndOffset = AllocSize;
// NB: This only works if we have zero overlapping partitions.
- iterator B = std::lower_bound(P.begin(), P.end(), BeginOffset);
- if (B != P.begin() && llvm::prior(B)->EndOffset > BeginOffset)
- B = llvm::prior(B);
- for (iterator I = B, E = P.end(); I != E && I->BeginOffset < EndOffset;
- ++I) {
+ iterator I = std::lower_bound(P.begin(), P.end(), BeginOffset);
+ if (I != P.begin() && llvm::prior(I)->EndOffset > BeginOffset)
+ I = llvm::prior(I);
+ iterator E = P.end();
+ bool IsSplit = llvm::next(I) != E && llvm::next(I)->BeginOffset < EndOffset;
+ for (; I != E && I->BeginOffset < EndOffset; ++I) {
PartitionUse NewPU(std::max(I->BeginOffset, BeginOffset),
- std::min(I->EndOffset, EndOffset), U);
+ std::min(I->EndOffset, EndOffset), U, IsSplit);
P.use_push_back(I, NewPU);
if (isa<PHINode>(U->getUser()) || isa<SelectInst>(U->getUser()))
P.PHIOrSelectOpMap[U]
}
}
- void handleLoadOrStore(Type *Ty, Instruction &I, const APInt &Offset) {
- uint64_t Size = DL.getTypeStoreSize(Ty);
-
- // If this memory access can be shown to *statically* extend outside the
- // bounds of of the allocation, it's behavior is undefined, so simply
- // ignore it. Note that this is more strict than the generic clamping
- // behavior of insertUse.
- if (Offset.isNegative() || Size > AllocSize ||
- Offset.ugt(AllocSize - Size))
- return markAsDead(I);
-
- insertUse(I, Offset, Size);
- }
-
void visitBitCastInst(BitCastInst &BC) {
if (BC.use_empty())
return markAsDead(BC);
void visitLoadInst(LoadInst &LI) {
assert(IsOffsetKnown);
- handleLoadOrStore(LI.getType(), LI, Offset);
+ uint64_t Size = DL.getTypeStoreSize(LI.getType());
+ insertUse(LI, Offset, Size);
}
void visitStoreInst(StoreInst &SI) {
assert(IsOffsetKnown);
- handleLoadOrStore(SI.getOperand(0)->getType(), SI, Offset);
+ uint64_t Size = DL.getTypeStoreSize(SI.getOperand(0)->getType());
+
+ // If this memory access can be shown to *statically* extend outside the
+ // bounds of of the allocation, it's behavior is undefined, so simply
+ // ignore it. Note that this is more strict than the generic clamping
+ // behavior of insertUse.
+ if (Offset.isNegative() || Size > AllocSize ||
+ Offset.ugt(AllocSize - Size))
+ return markAsDead(SI);
+
+ insertUse(SI, Offset, Size);
}
void visitMemSetInst(MemSetInst &II) {
Type *AllocaPartitioning::getCommonType(iterator I) const {
Type *Ty = 0;
for (const_use_iterator UI = use_begin(I), UE = use_end(I); UI != UE; ++UI) {
- if (!UI->U)
+ Use *U = UI->getUse();
+ if (!U)
continue; // Skip dead uses.
- if (isa<IntrinsicInst>(*UI->U->getUser()))
+ if (isa<IntrinsicInst>(*U->getUser()))
continue;
if (UI->BeginOffset != I->BeginOffset || UI->EndOffset != I->EndOffset)
continue;
Type *UserTy = 0;
- if (LoadInst *LI = dyn_cast<LoadInst>(UI->U->getUser()))
+ if (LoadInst *LI = dyn_cast<LoadInst>(U->getUser()))
UserTy = LI->getType();
- else if (StoreInst *SI = dyn_cast<StoreInst>(UI->U->getUser()))
+ else if (StoreInst *SI = dyn_cast<StoreInst>(U->getUser()))
UserTy = SI->getValueOperand()->getType();
else
return 0; // Bail if we have weird uses.
void AllocaPartitioning::printUsers(raw_ostream &OS, const_iterator I,
StringRef Indent) const {
for (const_use_iterator UI = use_begin(I), UE = use_end(I); UI != UE; ++UI) {
- if (!UI->U)
+ if (!UI->getUse())
continue; // Skip dead uses.
OS << Indent << " [" << UI->BeginOffset << "," << UI->EndOffset << ") "
- << "used by: " << *UI->U->getUser() << "\n";
- if (MemTransferInst *II = dyn_cast<MemTransferInst>(UI->U->getUser())) {
+ << "used by: " << *UI->getUse()->getUser() << "\n";
+ if (MemTransferInst *II =
+ dyn_cast<MemTransferInst>(UI->getUse()->getUser())) {
const MemTransferOffsets &MTO = MemTransferInstData.lookup(II);
bool IsDest;
if (!MTO.IsSplittable)
// new uses, and so we can use the initial size bound.
for (unsigned Idx = 0, Size = P.use_size(PI); Idx != Size; ++Idx) {
const AllocaPartitioning::PartitionUse &PU = P.getUse(PI, Idx);
- if (!PU.U)
+ if (!PU.getUse())
continue; // Skip dead use.
- visit(cast<Instruction>(PU.U->getUser()));
+ visit(cast<Instruction>(PU.getUse()->getUser()));
}
}
// inside the load.
AllocaPartitioning::use_iterator UI
= P.findPartitionUseForPHIOrSelectOperand(InUse);
- assert(isa<PHINode>(*UI->U->getUser()));
- UI->U = &Load->getOperandUse(Load->getPointerOperandIndex());
+ assert(isa<PHINode>(*UI->getUse()->getUser()));
+ UI->setUse(&Load->getOperandUse(Load->getPointerOperandIndex()));
}
DEBUG(dbgs() << " speculated to: " << *NewPN << "\n");
}
PUs[i] = *UI;
// Clear out the use here so that the offsets into the use list remain
// stable but this use is ignored when rewriting.
- UI->U = 0;
+ UI->setUse(0);
}
}
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;
+ assert(PUs[i].getUse()->get() == LoadUse->get());
+ PUs[i].setUse(LoadUse);
P.use_push_back(PIs[i], PUs[i]);
}
}
static bool canConvertValue(const DataLayout &DL, Type *OldTy, Type *NewTy) {
if (OldTy == NewTy)
return true;
+ if (IntegerType *OldITy = dyn_cast<IntegerType>(OldTy))
+ if (IntegerType *NewITy = dyn_cast<IntegerType>(NewTy))
+ if (NewITy->getBitWidth() >= OldITy->getBitWidth())
+ return true;
if (DL.getTypeSizeInBits(NewTy) != DL.getTypeSizeInBits(OldTy))
return false;
if (!NewTy->isSingleValueType() || !OldTy->isSingleValueType())
"Value not convertable to type");
if (V->getType() == Ty)
return V;
+ if (IntegerType *OldITy = dyn_cast<IntegerType>(V->getType()))
+ if (IntegerType *NewITy = dyn_cast<IntegerType>(Ty))
+ if (NewITy->getBitWidth() > OldITy->getBitWidth())
+ return IRB.CreateZExt(V, NewITy);
if (V->getType()->isIntegerTy() && Ty->isPointerTy())
return IRB.CreateIntToPtr(V, Ty);
if (V->getType()->isPointerTy() && Ty->isIntegerTy())
ElementSize /= 8;
for (; I != E; ++I) {
- if (!I->U)
+ Use *U = I->getUse();
+ if (!U)
continue; // Skip dead use.
uint64_t BeginOffset = I->BeginOffset - PartitionBeginOffset;
= (NumElements == 1) ? Ty->getElementType()
: VectorType::get(Ty->getElementType(), NumElements);
- if (MemIntrinsic *MI = dyn_cast<MemIntrinsic>(I->U->getUser())) {
+ if (MemIntrinsic *MI = dyn_cast<MemIntrinsic>(U->getUser())) {
if (MI->isVolatile())
return false;
- if (MemTransferInst *MTI = dyn_cast<MemTransferInst>(I->U->getUser())) {
+ if (MemTransferInst *MTI = dyn_cast<MemTransferInst>(U->getUser())) {
const AllocaPartitioning::MemTransferOffsets &MTO
= P.getMemTransferOffsets(*MTI);
if (!MTO.IsSplittable)
return false;
}
- } else if (I->U->get()->getType()->getPointerElementType()->isStructTy()) {
+ } else if (U->get()->getType()->getPointerElementType()->isStructTy()) {
// Disable vector promotion when there are loads or stores of an FCA.
return false;
- } else if (LoadInst *LI = dyn_cast<LoadInst>(I->U->getUser())) {
+ } else if (LoadInst *LI = dyn_cast<LoadInst>(U->getUser())) {
if (LI->isVolatile())
return false;
if (!canConvertValue(TD, PartitionTy, LI->getType()))
return false;
- } else if (StoreInst *SI = dyn_cast<StoreInst>(I->U->getUser())) {
+ } else if (StoreInst *SI = dyn_cast<StoreInst>(U->getUser())) {
if (SI->isVolatile())
return false;
if (!canConvertValue(TD, SI->getValueOperand()->getType(), PartitionTy))
// unsplittable entry (which we may make splittable later).
bool WholeAllocaOp = false;
for (; I != E; ++I) {
- if (!I->U)
+ Use *U = I->getUse();
+ if (!U)
continue; // Skip dead use.
uint64_t RelBegin = I->BeginOffset - AllocBeginOffset;
if (RelEnd > Size)
return false;
- if (LoadInst *LI = dyn_cast<LoadInst>(I->U->getUser())) {
+ if (LoadInst *LI = dyn_cast<LoadInst>(U->getUser())) {
if (LI->isVolatile())
return false;
if (RelBegin == 0 && RelEnd == Size)
if (RelBegin != 0 || RelEnd != Size ||
!canConvertValue(TD, AllocaTy, LI->getType()))
return false;
- } else if (StoreInst *SI = dyn_cast<StoreInst>(I->U->getUser())) {
+ } else if (StoreInst *SI = dyn_cast<StoreInst>(U->getUser())) {
Type *ValueTy = SI->getValueOperand()->getType();
if (SI->isVolatile())
return false;
if (RelBegin != 0 || RelEnd != Size ||
!canConvertValue(TD, ValueTy, AllocaTy))
return false;
- } else if (MemIntrinsic *MI = dyn_cast<MemIntrinsic>(I->U->getUser())) {
+ } else if (MemIntrinsic *MI = dyn_cast<MemIntrinsic>(U->getUser())) {
if (MI->isVolatile() || !isa<Constant>(MI->getLength()))
return false;
- if (MemTransferInst *MTI = dyn_cast<MemTransferInst>(I->U->getUser())) {
+ if (MemTransferInst *MTI = dyn_cast<MemTransferInst>(U->getUser())) {
const AllocaPartitioning::MemTransferOffsets &MTO
= P.getMemTransferOffsets(*MTI);
if (!MTO.IsSplittable)
return false;
}
- } else if (IntrinsicInst *II = dyn_cast<IntrinsicInst>(I->U->getUser())) {
+ } else if (IntrinsicInst *II = dyn_cast<IntrinsicInst>(U->getUser())) {
if (II->getIntrinsicID() != Intrinsic::lifetime_start &&
II->getIntrinsicID() != Intrinsic::lifetime_end)
return false;
// The offset of the partition user currently being rewritten.
uint64_t BeginOffset, EndOffset;
+ bool IsSplit;
Use *OldUse;
Instruction *OldPtr;
NewAllocaEndOffset(NewEndOffset),
NewAllocaTy(NewAI.getAllocatedType()),
VecTy(), ElementTy(), ElementSize(), IntTy(),
- BeginOffset(), EndOffset() {
+ BeginOffset(), EndOffset(), IsSplit(), OldUse(), OldPtr() {
}
/// \brief Visit the users of the alloca partition and rewrite them.
}
bool CanSROA = true;
for (; I != E; ++I) {
- if (!I->U)
+ if (!I->getUse())
continue; // Skip dead uses.
BeginOffset = I->BeginOffset;
EndOffset = I->EndOffset;
- OldUse = I->U;
- OldPtr = cast<Instruction>(I->U->get());
+ IsSplit = I->isSplit();
+ OldUse = I->getUse();
+ OldPtr = cast<Instruction>(OldUse->get());
NamePrefix = (Twine(NewAI.getName()) + "." + Twine(BeginOffset)).str();
- CanSROA &= visit(cast<Instruction>(I->U->getUser()));
+ CanSROA &= visit(cast<Instruction>(OldUse->getUser()));
}
if (VecTy) {
assert(CanSROA);
assert(OldOp == OldPtr);
uint64_t Size = EndOffset - BeginOffset;
- bool IsSplitIntLoad = Size < TD.getTypeStoreSize(LI.getType());
-
- // If this memory access can be shown to *statically* extend outside the
- // bounds of the original allocation it's behavior is undefined. Rather
- // than trying to transform it, just replace it with undef.
- // FIXME: We should do something more clever for functions being
- // instrumented by asan.
- // FIXME: Eventually, once ASan and friends can flush out bugs here, this
- // should be transformed to a load of null making it unreachable.
- uint64_t OldAllocSize = TD.getTypeAllocSize(OldAI.getAllocatedType());
- if (TD.getTypeStoreSize(LI.getType()) > OldAllocSize) {
- LI.replaceAllUsesWith(UndefValue::get(LI.getType()));
- Pass.DeadInsts.insert(&LI);
- deleteIfTriviallyDead(OldOp);
- DEBUG(dbgs() << " to: undef!!\n");
- return true;
- }
IRBuilder<> IRB(&LI);
- Type *TargetTy = IsSplitIntLoad ? Type::getIntNTy(LI.getContext(), Size * 8)
- : LI.getType();
+ Type *TargetTy = IsSplit ? Type::getIntNTy(LI.getContext(), Size * 8)
+ : LI.getType();
bool IsPtrAdjusted = false;
Value *V;
if (VecTy) {
}
V = convertValue(TD, IRB, V, TargetTy);
- if (IsSplitIntLoad) {
+ if (IsSplit) {
assert(!LI.isVolatile());
assert(LI.getType()->isIntegerTy() &&
"Only integer type loads and stores are split");
+ assert(Size < TD.getTypeStoreSize(LI.getType()) &&
+ "Split load isn't smaller than original load");
assert(LI.getType()->getIntegerBitWidth() ==
TD.getTypeStoreSizeInBits(LI.getType()) &&
"Non-byte-multiple bit width");
- assert(LI.getType()->getIntegerBitWidth() ==
- TD.getTypeAllocSizeInBits(OldAI.getAllocatedType()) &&
- "Only alloca-wide loads can be split and recomposed");
// Move the insertion point just past the load so that we can refer to it.
IRB.SetInsertPoint(llvm::next(BasicBlock::iterator(&LI)));
// Create a placeholder value with the same type as LI to use as the
uint64_t Size = EndOffset - BeginOffset;
if (Size < TD.getTypeStoreSize(V->getType())) {
assert(!SI.isVolatile());
+ assert(IsSplit && "A seemingly split store isn't splittable");
assert(V->getType()->isIntegerTy() &&
"Only integer type loads and stores are split");
assert(V->getType()->getIntegerBitWidth() ==
TD.getTypeStoreSizeInBits(V->getType()) &&
"Non-byte-multiple bit width");
- assert(V->getType()->getIntegerBitWidth() ==
- TD.getTypeAllocSizeInBits(OldAI.getAllocatedType()) &&
- "Only alloca-wide stores can be split and recomposed");
IntegerType *NarrowTy = Type::getIntNTy(SI.getContext(), Size * 8);
V = extractInteger(TD, IRB, V, NarrowTy, BeginOffset,
getName(".extract"));
for (AllocaPartitioning::use_iterator UI = P.use_begin(PI),
UE = P.use_end(PI);
UI != UE && !IsLive; ++UI)
- if (UI->U)
+ if (UI->getUse())
IsLive = true;
if (!IsLive)
return false; // No live uses left of this partition.
define i64 @test9() {
; Ensure we can handle loads off the end of an alloca even when wrapped in
-; weird bit casts and types. The result is undef, but this shouldn't crash
-; anything.
+; weird bit casts and types. This is valid IR due to the alignment and masking
+; off the bits past the end of the alloca.
+;
; CHECK: @test9
; CHECK-NOT: alloca
-; CHECK: ret i64 undef
+; CHECK: %[[b2:.*]] = zext i8 26 to i64
+; CHECK-NEXT: %[[s2:.*]] = shl i64 %[[b2]], 16
+; CHECK-NEXT: %[[m2:.*]] = and i64 undef, -16711681
+; CHECK-NEXT: %[[i2:.*]] = or i64 %[[m2]], %[[s2]]
+; CHECK-NEXT: %[[b1:.*]] = zext i8 0 to i64
+; CHECK-NEXT: %[[s1:.*]] = shl i64 %[[b1]], 8
+; CHECK-NEXT: %[[m1:.*]] = and i64 %[[i2]], -65281
+; CHECK-NEXT: %[[i1:.*]] = or i64 %[[m1]], %[[s1]]
+; CHECK-NEXT: %[[b0:.*]] = zext i8 0 to i64
+; CHECK-NEXT: %[[m0:.*]] = and i64 %[[i1]], -256
+; CHECK-NEXT: %[[i0:.*]] = or i64 %[[m0]], %[[b0]]
+; CHECK-NEXT: %[[result:.*]] = and i64 %[[i0]], 16777215
+; CHECK-NEXT: ret i64 %[[result]]
entry:
- %a = alloca { [3 x i8] }
+ %a = alloca { [3 x i8] }, align 8
%gep1 = getelementptr inbounds { [3 x i8] }* %a, i32 0, i32 0, i32 0
store i8 0, i8* %gep1, align 1
%gep2 = getelementptr inbounds { [3 x i8] }* %a, i32 0, i32 0, i32 1
store i8 26, i8* %gep3, align 1
%cast = bitcast { [3 x i8] }* %a to { i64 }*
%elt = getelementptr inbounds { i64 }* %cast, i32 0, i32 0
- %result = load i64* %elt
+ %load = load i64* %elt
+ %result = and i64 %load, 16777215
ret i64 %result
}
; Ensure we don't crash and handle undefined loads that straddle the end of the
; allocation.
; CHECK: @test13
-; CHECK: %[[ret:.*]] = zext i16 undef to i32
-; CHECK: ret i32 %[[ret]]
+; CHECK: %[[value:.*]] = zext i8 0 to i16
+; CHECK-NEXT: %[[ret:.*]] = zext i16 %[[value]] to i32
+; CHECK-NEXT: ret i32 %[[ret]]
entry:
- %a = alloca [3 x i8]
+ %a = alloca [3 x i8], align 2
%b0ptr = getelementptr [3 x i8]* %a, i64 0, i32 0
store i8 0, i8* %b0ptr
%b1ptr = getelementptr [3 x i8]* %a, i64 0, i32 1
entry:
%a = alloca <{ i1 }>, align 8
%b = alloca <{ i1 }>, align 8
-; Nothing of interest is simplified here.
-; CHECK: alloca
-; CHECK: alloca
+; CHECK: %[[a:.*]] = alloca i8, align 8
%b.i1 = bitcast <{ i1 }>* %b to i1*
store i1 %x, i1* %b.i1, align 8
%b.i8 = bitcast <{ i1 }>* %b to i8*
%foo = load i8* %b.i8, align 1
+; CHECK-NEXT: {{.*}} = zext i1 %x to i8
+; CHECK-NEXT: %[[ext:.*]] = zext i1 %x to i8
+; CHECK-NEXT: store i8 %[[ext]], i8* %[[a]], align 8
+; CHECK-NEXT: {{.*}} = load i8* %[[a]], align 8
%a.i8 = bitcast <{ i1 }>* %a to i8*
call void @llvm.memcpy.p0i8.p0i8.i32(i8* %a.i8, i8* %b.i8, i32 1, i32 1, i1 false) nounwind
%bar = load i8* %a.i8, align 1
%a.i1 = getelementptr inbounds <{ i1 }>* %a, i32 0, i32 0
%baz = load i1* %a.i1, align 1
+; CHECK-NEXT: %[[a_cast:.*]] = bitcast i8* %[[a]] to i1*
+; CHECK-NEXT: {{.*}} = load i1* %[[a_cast]], align 8
+
ret void
}