diff --git a/llvm/lib/Analysis/TargetLibraryInfo.cpp b/llvm/lib/Analysis/TargetLibraryInfo.cpp
--- a/llvm/lib/Analysis/TargetLibraryInfo.cpp
+++ b/llvm/lib/Analysis/TargetLibraryInfo.cpp
@@ -203,6 +203,7 @@
     TLI.setAvailable(LibFunc_getchar_unlocked);
     TLI.setAvailable(LibFunc_putc_unlocked);
     TLI.setAvailable(LibFunc_putchar_unlocked);
+    TLI.setUnavailable(LibFunc_memrchr);
 
     if (T.isMacOSXVersionLT(10, 5)) {
       TLI.setUnavailable(LibFunc_memset_pattern4);