[ARM][CGP] Clear SafeWrap before each search

The previous patch added a member set to store instructions that we
could allow to wrap. But this wasn't cleared between searches meaning
that they could get promoted, incorrectly, during the promotion of a
separate valid chain.

Differential Revision: https://reviews.llvm.org/D62254

llvm-svn: 361462

1 files changed, 1 insertions, 0 deletions

diff --git a/llvm/lib/Target/ARM/ARMCodeGenPrepare.cpp b/llvm/lib/Target/ARM/ARMCodeGenPrepare.cpp
index 83d5b860fbd..2fc5f4aaab5 100644
--- a/llvm/lib/Target/ARM/ARMCodeGenPrepare.cpp
+++ b/llvm/lib/Target/ARM/ARMCodeGenPrepare.cpp
@@ -906,6 +906,7 @@ bool ARMCodeGenPrepare::TryToPromote(Value *V) {
     return false;
 
   SafeToPromote.clear();
+  SafeWrap.clear();
 
   if (!isSupportedValue(V) || !shouldPromote(V) || !isLegalToPromote(V))
     return false;