From: NAKAMURA Takumi <geek4civic@gmail.com>
Date: Sat, 5 Jan 2013 05:14:23 +0000 (+0000)
Subject: DenseMap: Appease -fstrict-aliasing on g++-4.4.
X-Git-Url: http://plrg.eecs.uci.edu/git/?a=commitdiff_plain;h=5d295b41a3f4194778b6bc01a828b2115bd3a3f1;p=oota-llvm.git

DenseMap: Appease -fstrict-aliasing on g++-4.4.

With DenseMapInfo<Enum>, it is miscompiled on g++-4.4.

    static inline Enum getEmptyKey() { return Enum(<arbitrary int/unsigned value>); }

    isEauql(getEmptyKey(), ...)

The compiler mis-assumes the return value is not aliased to Enum.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@171600 91177308-0d34-0410-b5e6-96231b3b80d8
---

diff --git a/include/llvm/ADT/DenseMap.h b/include/llvm/ADT/DenseMap.h
index 8607fb7e9cc..4a2d13786f2 100644
--- a/include/llvm/ADT/DenseMap.h
+++ b/include/llvm/ADT/DenseMap.h
@@ -430,7 +430,8 @@ private:
     incrementNumEntries();
 
     // If we are writing over a tombstone, remember this.
-    if (!KeyInfoT::isEqual(TheBucket->first, getEmptyKey()))
+    const KeyT EmptyKey = getEmptyKey();
+    if (!KeyInfoT::isEqual(TheBucket->first, EmptyKey))
       decrementNumTombstones();
 
     return TheBucket;