From db40b5c899a94db50e63862af985a791ad0fa7b4 Mon Sep 17 00:00:00 2001 From: Bill Wendling Date: Sat, 26 Mar 2011 01:20:37 +0000 Subject: PR9561: A store with a negative offset (via GEP) could erroniously say that it completely overlaps a previous store, thus mistakenly deleting that store. Check for this condition. llvm-svn: 128319 --- llvm/lib/Transforms/Scalar/DeadStoreElimination.cpp | 2 ++ 1 file changed, 2 insertions(+) (limited to 'llvm/lib/Transforms') diff --git a/llvm/lib/Transforms/Scalar/DeadStoreElimination.cpp b/llvm/lib/Transforms/Scalar/DeadStoreElimination.cpp index 867a06ad202..d07cf0727a8 100644 --- a/llvm/lib/Transforms/Scalar/DeadStoreElimination.cpp +++ b/llvm/lib/Transforms/Scalar/DeadStoreElimination.cpp @@ -354,8 +354,10 @@ static bool isCompleteOverwrite(const AliasAnalysis::Location &Later, // In this case, we see if the later store completely overlaps all bytes // stored by the previous store. if (Off1 < Off2 || // Earlier starts before Later. + Off2 < 0 || // Later is -. Off1+Earlier.Size > Off2+Later.Size) // Earlier goes beyond Later. return false; + // Otherwise, we have complete overlap. return true; } -- cgit v1.2.3