diff options
| -rw-r--r-- | lib/Transforms/Scalar/DeadStoreElimination.cpp | 11 | ||||
| -rw-r--r-- | test/Transforms/DeadStoreElimination/simple.ll | 15 |
2 files changed, 24 insertions, 2 deletions
diff --git a/lib/Transforms/Scalar/DeadStoreElimination.cpp b/lib/Transforms/Scalar/DeadStoreElimination.cpp index 5eff0e5a36..dcae458606 100644 --- a/lib/Transforms/Scalar/DeadStoreElimination.cpp +++ b/lib/Transforms/Scalar/DeadStoreElimination.cpp @@ -740,12 +740,19 @@ bool DSE::handleEndBlock(BasicBlock &BB) { continue; } - if (isa<AllocaInst>(BBI) || isAllocLikeFn(BBI)) { + if (isa<AllocaInst>(BBI)) { + // Remove allocas from the list of dead stack objects; there can't be + // any references before the definition. DeadStackObjects.remove(BBI); continue; } if (CallSite CS = cast<Value>(BBI)) { + // Remove allocation function calls from the list of dead stack objects; + // there can't be any references before the definition. + if (isAllocLikeFn(BBI)) + DeadStackObjects.remove(BBI); + // If this call does not access memory, it can't be loading any of our // pointers. if (AA->doesNotAccessMemory(CS)) @@ -771,7 +778,7 @@ bool DSE::handleEndBlock(BasicBlock &BB) { // If all of the allocas were clobbered by the call then we're not going // to find anything else to process. if (DeadStackObjects.empty()) - return MadeChange; + break; continue; } diff --git a/test/Transforms/DeadStoreElimination/simple.ll b/test/Transforms/DeadStoreElimination/simple.ll index a38620695e..ed53ab7e60 100644 --- a/test/Transforms/DeadStoreElimination/simple.ll +++ b/test/Transforms/DeadStoreElimination/simple.ll @@ -276,3 +276,18 @@ define void @test22(i1 %i, i32 %k, i32 %m) nounwind { ; CHECK-NEXT: ret void ret void } + +; PR13547 +; CHECK: @test23 +; CHECK: store i8 97 +; CHECK: store i8 0 +declare noalias i8* @strdup(i8* nocapture) nounwind +define noalias i8* @test23() nounwind uwtable ssp { + %x = alloca [2 x i8], align 1 + %arrayidx = getelementptr inbounds [2 x i8]* %x, i64 0, i64 0 + store i8 97, i8* %arrayidx, align 1 + %arrayidx1 = getelementptr inbounds [2 x i8]* %x, i64 0, i64 1 + store i8 0, i8* %arrayidx1, align 1 + %call = call i8* @strdup(i8* %arrayidx) nounwind + ret i8* %call +} |