[llvm-commits] [llvm] r171600 - /llvm/trunk/include/llvm/ADT/DenseMap.h

[NAKAMURA Takumi]

Author: chapuni
Date: Fri Jan  4 23:14:23 2013
New Revision: 171600

URL: http://llvm.org/viewvc/llvm-project?rev=171600&view=rev
Log:
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.

Modified:
    llvm/trunk/include/llvm/ADT/DenseMap.h

Modified: llvm/trunk/include/llvm/ADT/DenseMap.h
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/include/llvm/ADT/DenseMap.h?rev=171600&r1=171599&r2=171600&view=diff
==============================================================================
--- llvm/trunk/include/llvm/ADT/DenseMap.h (original)
+++ llvm/trunk/include/llvm/ADT/DenseMap.h Fri Jan  4 23:14:23 2013
@@ -430,7 +430,8 @@
     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;