diff --git a/include/llvm/Target/TargetLibraryInfo.h b/include/llvm/Target/TargetLibraryInfo.h
index 0914b5daa4b..02a1a3ca23a 100644
--- a/include/llvm/Target/TargetLibraryInfo.h
+++ b/include/llvm/Target/TargetLibraryInfo.h
@@ -51,6 +51,7 @@ public:
   static char ID;
   TargetLibraryInfo();
   TargetLibraryInfo(const Triple &T);
+  explicit TargetLibraryInfo(const TargetLibraryInfo &TLI);
   
   /// has - This function is used by optimizations that want to match on or form
   /// a given library function.
diff --git a/lib/Target/TargetLibraryInfo.cpp b/lib/Target/TargetLibraryInfo.cpp
index e336b09291a..4b985b8c654 100644
--- a/lib/Target/TargetLibraryInfo.cpp
+++ b/lib/Target/TargetLibraryInfo.cpp
@@ -61,6 +61,12 @@ TargetLibraryInfo::TargetLibraryInfo(const Triple &T) : ImmutablePass(ID) {
   initialize(*this, T);
 }
 
+TargetLibraryInfo::TargetLibraryInfo(const TargetLibraryInfo &TLI)
+  : ImmutablePass(ID) {
+  memcpy(AvailableArray, TLI.AvailableArray, sizeof(AvailableArray));
+}
+
+
 /// disableAllFunctions - This disables all builtins, which is used for options
 /// like -fno-builtin.
 void TargetLibraryInfo::disableAllFunctions() {