bool getUnderlyingObjectsForCodeGen(const Value *V,
SmallVectorImpl<Value *> &Objects);
- /// Finds alloca where the value comes from.
- AllocaInst *findAllocaForValue(Value *V);
- inline const AllocaInst *findAllocaForValue(const Value *V) {
- return findAllocaForValue(const_cast<Value *>(V));
+ /// Returns unique alloca where the value comes from, or nullptr.
+ /// If OffsetZero is true check that V points to the begining of the alloca.
+ AllocaInst *findAllocaForValue(Value *V, bool OffsetZero = false);
+ inline const AllocaInst *findAllocaForValue(const Value *V,
+ bool OffsetZero = false) {
+ return findAllocaForValue(const_cast<Value *>(V), OffsetZero);
}
/// Return true if the only users of this pointer are lifetime markers.
}
static AllocaInst *
-findAllocaForValue(Value *V, DenseMap<Value *, AllocaInst *> &AllocaForValue) {
+findAllocaForValue(Value *V, DenseMap<Value *, AllocaInst *> &AllocaForValue,
+ bool OffsetZero) {
if (AllocaInst *AI = dyn_cast<AllocaInst>(V))
return AI;
// See if we've already calculated (or started to calculate) alloca for a
AllocaForValue[V] = nullptr;
AllocaInst *Res = nullptr;
if (CastInst *CI = dyn_cast<CastInst>(V))
- Res = findAllocaForValue(CI->getOperand(0), AllocaForValue);
- else if (auto *SI = dyn_cast<SelectInst>(V)) {
- Res = findAllocaForValue(SI->getTrueValue(), AllocaForValue);
- if (!Res)
- return nullptr;
- AllocaInst *F = findAllocaForValue(SI->getFalseValue(), AllocaForValue);
- if (F != Res)
- return nullptr;
- } else if (PHINode *PN = dyn_cast<PHINode>(V)) {
+ Res = findAllocaForValue(CI->getOperand(0), AllocaForValue, OffsetZero);
+ else if (PHINode *PN = dyn_cast<PHINode>(V)) {
for (Value *IncValue : PN->incoming_values()) {
// Allow self-referencing phi-nodes.
if (IncValue == PN)
continue;
- AllocaInst *IncValueAI = findAllocaForValue(IncValue, AllocaForValue);
+ AllocaInst *IncValueAI =
+ findAllocaForValue(IncValue, AllocaForValue, OffsetZero);
// AI for incoming values should exist and should all be equal.
if (IncValueAI == nullptr || (Res != nullptr && IncValueAI != Res))
return nullptr;
Res = IncValueAI;
}
- } else if (GetElementPtrInst *EP = dyn_cast<GetElementPtrInst>(V)) {
- Res = findAllocaForValue(EP->getPointerOperand(), AllocaForValue);
+ } else if (auto *SI = dyn_cast<SelectInst>(V)) {
+ Res = findAllocaForValue(SI->getTrueValue(), AllocaForValue, OffsetZero);
+ if (!Res)
+ return nullptr;
+ AllocaInst *F =
+ findAllocaForValue(SI->getFalseValue(), AllocaForValue, OffsetZero);
+ if (F != Res)
+ return nullptr;
+ } else if (GetElementPtrInst *GEP = dyn_cast<GetElementPtrInst>(V)) {
+ if (OffsetZero && !GEP->hasAllZeroIndices())
+ return nullptr;
+ Res = findAllocaForValue(GEP->getPointerOperand(), AllocaForValue,
+ OffsetZero);
}
if (Res)
AllocaForValue[V] = Res;
return Res;
}
-AllocaInst *llvm::findAllocaForValue(Value *V) {
+AllocaInst *llvm::findAllocaForValue(Value *V, bool OffsetZero) {
DenseMap<Value *, AllocaInst *> AllocaForValue;
- return ::findAllocaForValue(V, AllocaForValue);
+ return ::findAllocaForValue(V, AllocaForValue, OffsetZero);
}
static bool onlyUsedByLifetimeMarkersOrDroppableInstsHelper(
struct FindAllocaForValueTestParams {
const char *IR;
- bool Result;
+ bool AnyOffsetResult;
+ bool ZeroOffsetResult;
};
class FindAllocaForValueTest
%r = bitcast i64* %a to i32*
ret void
})",
- true},
+ true, true},
{R"(
define void @test() {
%r = getelementptr i32, i32* %a, i32 1
ret void
})",
- true},
+ true, false},
+
+ {R"(
+ define void @test() {
+ %a = alloca i32
+ %r = getelementptr i32, i32* %a, i32 0
+ ret void
+ })",
+ true, true},
{R"(
define void @test(i1 %cond) {
exit:
ret void
})",
- true},
+ true, true},
{R"(
define void @test(i1 %cond) {
%r = select i1 %cond, i32* %a, i32* %a
ret void
})",
- true},
+ true, true},
{R"(
define void @test(i1 %cond) {
%r = select i1 %cond, i32* %a, i32* %b
ret void
})",
- false},
+ false, false},
{R"(
define void @test(i1 %cond) {
exit:
ret void
})",
- true},
+ true, false},
{R"(
define void @test(i1 %cond) {
exit:
ret void
})",
- false},
+ false, false},
{R"(
define void @test(i1 %cond, i64* %a) {
%r = bitcast i64* %a to i32*
ret void
})",
- false},
+ false, false},
{R"(
define void @test(i1 %cond) {
exit:
ret void
})",
- false},
+ false, false},
};
TEST_P(FindAllocaForValueTest, findAllocaForValue) {
Function *F = M->getFunction("test");
Instruction *I = &findInstructionByName(F, "r");
const AllocaInst *AI = findAllocaForValue(I);
- EXPECT_EQ(!!AI, GetParam().Result);
+ EXPECT_EQ(!!AI, GetParam().AnyOffsetResult);
+}
+
+TEST_P(FindAllocaForValueTest, findAllocaForValueZeroOffset) {
+ auto M = parseModule(GetParam().IR);
+ Function *F = M->getFunction("test");
+ Instruction *I = &findInstructionByName(F, "r");
+ const AllocaInst *AI = findAllocaForValue(I, true);
+ EXPECT_EQ(!!AI, GetParam().ZeroOffsetResult);
}
INSTANTIATE_TEST_CASE_P(FindAllocaForValueTest, FindAllocaForValueTest,