diff --git a/lib/Object/IRObjectFile.cpp b/lib/Object/IRObjectFile.cpp
index d01910811a6..0639c71d1b0 100644
--- a/lib/Object/IRObjectFile.cpp
+++ b/lib/Object/IRObjectFile.cpp
@@ -245,6 +245,11 @@ uint32_t IRObjectFile::getSymbolFlags(DataRefImpl Symb) const {
       Res |= BasicSymbolRef::SF_FormatSpecific;
   }
 
+  if (auto *F = dyn_cast<Function>(GV)) {
+    if (F->getName().startswith("llvm."))
+      Res |= BasicSymbolRef::SF_FormatSpecific;
+  }
+
   return Res;
 }
 
diff --git a/test/Object/mangle-ir.ll b/test/Object/mangle-ir.ll
index 725d788a19a..5b3cd09cb7c 100644
--- a/test/Object/mangle-ir.ll
+++ b/test/Object/mangle-ir.ll
@@ -2,7 +2,13 @@
 
 target datalayout = "m:o"
 
+; CHECK-NOT: memcpy
 ; CHECK: T _f
+; CHECK-NOT: memcpy
+
 define void @f() {
+  tail call void @llvm.memcpy.p0i8.p0i8.i64(i8* null, i8* null, i64 0, i32 1, i1 false)
   ret void
 }
+
+declare void @llvm.memcpy.p0i8.p0i8.i64(i8* nocapture, i8* nocapture readonly, i64, i32, i1)