diff --git a/lib/Target/Blackfin/BlackfinIntrinsicInfo.cpp b/lib/Target/Blackfin/BlackfinIntrinsicInfo.cpp
index ea9480d7625..34a8d3809ea 100644
--- a/lib/Target/Blackfin/BlackfinIntrinsicInfo.cpp
+++ b/lib/Target/Blackfin/BlackfinIntrinsicInfo.cpp
@@ -53,6 +53,10 @@ std::string BlackfinIntrinsicInfo::getName(unsigned IntrID, const Type **Tys,
 
 unsigned
 BlackfinIntrinsicInfo::lookupName(const char *Name, unsigned Len) const {
+  if (Len < 5 || Name[4] != '.' || Name[0] != 'l' || Name[1] != 'l'
+      || Name[2] != 'v' || Name[3] != 'm')
+    return 0;  // All intrinsics start with 'llvm.'
+
 #define GET_FUNCTION_RECOGNIZER
 #include "BlackfinGenIntrinsics.inc"
 #undef GET_FUNCTION_RECOGNIZER
diff --git a/lib/Target/MBlaze/MBlazeIntrinsicInfo.cpp b/lib/Target/MBlaze/MBlazeIntrinsicInfo.cpp
index c8faffc8452..4931860912a 100644
--- a/lib/Target/MBlaze/MBlazeIntrinsicInfo.cpp
+++ b/lib/Target/MBlaze/MBlazeIntrinsicInfo.cpp
@@ -57,6 +57,10 @@ std::string MBlazeIntrinsicInfo::getName(unsigned IntrID, const Type **Tys,
 
 unsigned MBlazeIntrinsicInfo::
 lookupName(const char *Name, unsigned Len) const {
+  if (Len < 5 || Name[4] != '.' || Name[0] != 'l' || Name[1] != 'l'
+      || Name[2] != 'v' || Name[3] != 'm')
+    return 0;  // All intrinsics start with 'llvm.'
+
 #define GET_FUNCTION_RECOGNIZER
 #include "MBlazeGenIntrinsics.inc"
 #undef GET_FUNCTION_RECOGNIZER