Index: cfe/trunk/lib/CodeGen/CGBuiltin.cpp
===================================================================
--- cfe/trunk/lib/CodeGen/CGBuiltin.cpp
+++ cfe/trunk/lib/CodeGen/CGBuiltin.cpp
@@ -6460,8 +6460,8 @@
       Indices[i] = i;
     for (unsigned i = NumElts; i != 8; ++i)
       Indices[i] = NumElts;
-    Cmp = CGF.Builder.CreateShuffleVector(Cmp, UndefValue::get(Cmp->getType()),
-                                          Indices);
+    Cmp = CGF.Builder.CreateShuffleVector(
+        Cmp, llvm::Constant::getNullValue(Cmp->getType()), Indices);
   }
   return CGF.Builder.CreateBitCast(Cmp,
                                    IntegerType::get(CGF.getLLVMContext(),
Index: cfe/trunk/test/CodeGen/avx512vl-builtins.c
===================================================================
--- cfe/trunk/test/CodeGen/avx512vl-builtins.c
+++ cfe/trunk/test/CodeGen/avx512vl-builtins.c
@@ -8,6 +8,7 @@
 __mmask8 test_mm_cmpeq_epu32_mask(__m128i __a, __m128i __b) {
   // CHECK-LABEL: @test_mm_cmpeq_epu32_mask
   // CHECK: icmp eq <4 x i32> %{{.*}}, %{{.*}}
+  // CHECK: shufflevector <4 x i1> %{{.*}}, <4 x i1> zeroinitializer, <8 x i32> <i32 0, i32 1, i32 2, i32 3, i32 4, i32 4, i32 4, i32 4>
   return (__mmask8)_mm_cmpeq_epu32_mask(__a, __b);
 }