diff --git a/clang/lib/Headers/avx2intrin.h b/clang/lib/Headers/avx2intrin.h
--- a/clang/lib/Headers/avx2intrin.h
+++ b/clang/lib/Headers/avx2intrin.h
@@ -740,6 +740,8 @@
   return (__m256i)__builtin_shufflevector((__v2di)__X, (__v2di)__X, 0, 1, 0, 1);
 }
 
+#define _mm_broadcastsi128_si256(X) _mm256_broadcastsi128_si256(X)
+
 #define _mm_blend_epi32(V1, V2, M) \
   (__m128i)__builtin_ia32_pblendd128((__v4si)(__m128i)(V1), \
                                      (__v4si)(__m128i)(V2), (int)(M))
diff --git a/clang/test/CodeGen/avx2-builtins.c b/clang/test/CodeGen/avx2-builtins.c
--- a/clang/test/CodeGen/avx2-builtins.c
+++ b/clang/test/CodeGen/avx2-builtins.c
@@ -208,6 +208,12 @@
   return _mm256_broadcastsi128_si256(a);
 }
 
+__m256i test_mm_broadcastsi128_si256(__m128i a) {
+  // CHECK-LABEL: test_mm_broadcastsi128_si256
+  // CHECK: shufflevector <2 x i64> %{{.*}}, <2 x i64> %{{.*}}, <4 x i32> <i32 0, i32 1, i32 0, i32 1>
+  return _mm_broadcastsi128_si256(a);
+}
+
 __m128 test_mm_broadcastss_ps(__m128 a) {
   // CHECK-LABEL: test_mm_broadcastss_ps
   // CHECK-NOT: @llvm.x86.avx2.vbroadcast.ss.ps