Index: lib/Target/X86/X86DiscriminateMemOps.cpp
===================================================================
--- lib/Target/X86/X86DiscriminateMemOps.cpp
+++ lib/Target/X86/X86DiscriminateMemOps.cpp
@@ -137,6 +137,7 @@
         Changed = true;
         std::pair<DenseSet<unsigned>::iterator, bool> MustInsert =
             Set.insert(DI->getBaseDiscriminator());
+        (void)MustInsert; // Silence warning in release build.
         assert(MustInsert.second && "New discriminator shouldn't be present in set");
       }