From 750d7616c6d9ed5a40de1ac8f74fb40afd82ebc6 Mon Sep 17 00:00:00 2001 From: Craig Topper Date: Tue, 14 Aug 2012 07:32:05 +0000 Subject: [PATCH] Change greater than to greater than or equal so that an identical sized store to the same offset is treated as completing overwriting. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@161857 91177308-0d34-0410-b5e6-96231b3b80d8 --- .../Scalar/DeadStoreElimination.cpp | 2 +- .../Transforms/DeadStoreElimination/simple.ll | 19 +++++++++++++++++++ 2 files changed, 20 insertions(+), 1 deletion(-) diff --git a/lib/Transforms/Scalar/DeadStoreElimination.cpp b/lib/Transforms/Scalar/DeadStoreElimination.cpp index dcae458606e..8b1283ff253 100644 --- a/lib/Transforms/Scalar/DeadStoreElimination.cpp +++ b/lib/Transforms/Scalar/DeadStoreElimination.cpp @@ -378,7 +378,7 @@ static OverwriteResult isOverwrite(const AliasAnalysis::Location &Later, // // We have to be careful here as *Off is signed while *.Size is unsigned. if (EarlierOff >= LaterOff && - Later.Size > Earlier.Size && + Later.Size >= Earlier.Size && uint64_t(EarlierOff - LaterOff) + Earlier.Size <= Later.Size) return OverwriteComplete; diff --git a/test/Transforms/DeadStoreElimination/simple.ll b/test/Transforms/DeadStoreElimination/simple.ll index ed53ab7e607..7a8cdd531b5 100644 --- a/test/Transforms/DeadStoreElimination/simple.ll +++ b/test/Transforms/DeadStoreElimination/simple.ll @@ -291,3 +291,22 @@ define noalias i8* @test23() nounwind uwtable ssp { %call = call i8* @strdup(i8* %arrayidx) nounwind ret i8* %call } + +; Make sure same sized store to later element is deleted +; CHECK: @test24 +; CHECK-NOT: store i32 0 +; CHECK-NOT: store i32 0 +; CHECK: store i32 %b +; CHECK: store i32 %c +; CHECK: ret void +define void @test24([2 x i32]* %a, i32 %b, i32 %c) nounwind { + %1 = getelementptr inbounds [2 x i32]* %a, i64 0, i64 0 + store i32 0, i32* %1, align 4 + %2 = getelementptr inbounds [2 x i32]* %a, i64 0, i64 1 + store i32 0, i32* %2, align 4 + %3 = getelementptr inbounds [2 x i32]* %a, i64 0, i64 0 + store i32 %b, i32* %3, align 4 + %4 = getelementptr inbounds [2 x i32]* %a, i64 0, i64 1 + store i32 %c, i32* %4, align 4 + ret void +}