Index: lib/Headers/avx512fintrin.h
===================================================================
--- lib/Headers/avx512fintrin.h
+++ lib/Headers/avx512fintrin.h
@@ -7965,6 +7965,30 @@
              (__mmask16) __U);
 }
 
+static __inline__ __m512d __DEFAULT_FN_ATTRS
+_mm512_castpd128_pd512 (__m128d __A)
+{
+  return __builtin_shufflevector( __A, __A, 0, 1, -1, -1, -1, -1, -1, -1);
+}
+
+static __inline__ __m512 __DEFAULT_FN_ATTRS
+_mm512_castps128_ps512 (__m128 __A)
+{
+    return  __builtin_shufflevector( __A, __A, 0, 1, 2, 3, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1);
+}
+
+static __inline__ __m512i __DEFAULT_FN_ATTRS
+_mm512_castsi128_si512 (__m128i __A)
+{
+   return  __builtin_shufflevector( __A, __A, 0, 1, -1, -1, -1, -1, -1, -1);
+}
+
+static __inline__ __m512i __DEFAULT_FN_ATTRS
+_mm512_castsi256_si512 (__m256i __A)
+{
+   return  __builtin_shufflevector( __A, __A, 0, 1, 2, 3, -1, -1, -1, -1);
+}
+
 
 #undef __DEFAULT_FN_ATTRS
 
Index: test/CodeGen/avx512f-builtins.c
===================================================================
--- test/CodeGen/avx512f-builtins.c
+++ test/CodeGen/avx512f-builtins.c
@@ -5528,3 +5528,28 @@
   // CHECK: @llvm.x86.avx512.mask.mova.ps.512
   return _mm512_maskz_mov_ps(__U, __A); 
 }
+
+__m512d test_mm512_castpd128_pd512(__m128d __A) {
+  // CHECK-LABEL: @test_mm512_castpd128_pd512
+  // CHECK: shufflevector <2 x double> %1, <2 x double> %2, <8 x i32> <i32 0, i32 1, i32 undef, i32 undef, i32 undef, i32 undef, i32 undef, i32 undef>
+  return _mm512_castpd128_pd512(__A); 
+}
+
+__m512 test_mm512_castps128_ps512(__m128 __A) {
+  // CHECK-LABEL: @test_mm512_castps128_ps512
+  // CHECK: shufflevector <4 x float> %1, <4 x float> %2, <16 x i32> <i32 0, i32 1, i32 2, i32 3, i32 undef, i32 undef, i32 undef, i32 undef, i32 undef, i32 undef, i32 undef, i32 undef, i32 undef, i32 undef, i32 undef, i32 undef>
+  return _mm512_castps128_ps512(__A); 
+}
+
+__m512i test_mm512_castsi128_si512(__m128i __A) {
+  // CHECK-LABEL: @test_mm512_castsi128_si512
+  // CHECK: shufflevector <2 x i64> %1, <2 x i64> %2, <8 x i32> <i32 0, i32 1, i32 undef, i32 undef, i32 undef, i32 undef, i32 undef, i32 undef>
+  return _mm512_castsi128_si512(__A); 
+}
+
+__m512i test_mm512_castsi256_si512(__m256i __A) {
+  // CHECK-LABEL: @test_mm512_castsi256_si512
+  // CHECK: shufflevector <4 x i64> %1, <4 x i64> %2, <8 x i32> <i32 0, i32 1, i32 2, i32 3, i32 undef, i32 undef, i32 undef, i32 undef>
+  return _mm512_castsi256_si512(__A); 
+}
+