diff --git a/include/clang/Basic/BuiltinsX86.def b/include/clang/Basic/BuiltinsX86.def
index 9361da6..c9afee6 100644
--- a/include/clang/Basic/BuiltinsX86.def
+++ b/include/clang/Basic/BuiltinsX86.def
@@ -641,4 +641,18 @@
 BUILTIN(__builtin_ia32_vfmsubaddps256, "V8fV8fV8fV8f", "")
 BUILTIN(__builtin_ia32_vfmsubaddpd256, "V4dV4dV4dV4d", "")
 
+// XOP
+BUILTIN(__builtin_ia32_vpmacssww, "V8sV8sV8sV8s", "")
+BUILTIN(__builtin_ia32_vpmacsww, "V8sV8sV8sV8s", "")
+BUILTIN(__builtin_ia32_vpmacsswd, "V4iV8sV8sV4i", "")
+BUILTIN(__builtin_ia32_vpmacswd, "V4iV8sV8sV4i", "")
+BUILTIN(__builtin_ia32_vpmacssdd, "V4iV4iV4iV4i", "")
+BUILTIN(__builtin_ia32_vpmacsdd, "V4iV4iV4iV4i", "")
+BUILTIN(__builtin_ia32_vpmacssdql, "V2LLiV4iV4iV2LLi", "")
+BUILTIN(__builtin_ia32_vpmacsdql, "V2LLiV4iV4iV2LLi", "")
+BUILTIN(__builtin_ia32_vpmacssdqh, "V2LLiV4iV4iV2LLi", "")
+BUILTIN(__builtin_ia32_vpmacsdqh, "V2LLiV4iV4iV2LLi", "")
+BUILTIN(__builtin_ia32_vpmadcsswd, "V4iV8sV8sV4i", "")
+BUILTIN(__builtin_ia32_vpmadcswd, "V4iV8sV8sV4i", "")
+
 #undef BUILTIN
diff --git a/lib/Headers/CMakeLists.txt b/lib/Headers/CMakeLists.txt
index 3043e03..6e9cc68 100644
--- a/lib/Headers/CMakeLists.txt
+++ b/lib/Headers/CMakeLists.txt
@@ -31,6 +31,7 @@
   wmmintrin.h
   x86intrin.h
   xmmintrin.h
+  xopintrin.h
   cpuid.h
   unwind.h
   module.map
diff --git a/lib/Headers/x86intrin.h b/lib/Headers/x86intrin.h
index cdbf439..556cd01 100644
--- a/lib/Headers/x86intrin.h
+++ b/lib/Headers/x86intrin.h
@@ -54,6 +54,10 @@
 #include <fma4intrin.h>
 #endif
 
-// FIXME: XOP, LWP
+#ifdef __XOP__
+#include <xopintrin.h>
+#endif
+
+// FIXME: LWP
 
 #endif /* __X86INTRIN_H */
diff --git a/lib/Headers/xopintrin.h b/lib/Headers/xopintrin.h
new file mode 100644
index 0000000..7425611
--- /dev/null
+++ b/lib/Headers/xopintrin.h
@@ -0,0 +1,111 @@
+/*===---- xopintrin.h - FMA4 intrinsics ------------------------------------===
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ *
+ *===-----------------------------------------------------------------------===
+ */
+
+#ifndef __X86INTRIN_H
+#error "Never use <fma4intrin.h> directly; include <x86intrin.h> instead."
+#endif
+
+#ifndef __XOPINTRIN_H
+#define __XOPINTRIN_H
+
+#ifndef __XOP__
+# error "XOP instruction set is not enabled"
+#else
+
+#include <fma4intrin.h>
+
+static __inline__ __m128i __attribute__((__always_inline__, __nodebug__))
+_mm_maccs_epi16(__m128i __A, __m128i __B, __m128i __C)
+{
+  return (__m128i)__builtin_ia32_vpmacssww((__v8hi)__A, (__v8hi)__B, (__v8hi)__C);
+}
+
+static __inline__ __m128i __attribute__((__always_inline__, __nodebug__))
+_mm_macc_epi16(__m128i __A, __m128i __B, __m128i __C)
+{
+  return (__m128i)__builtin_ia32_vpmacsww((__v8hi)__A, (__v8hi)__B, (__v8hi)__C);
+}
+
+static __inline__ __m128i __attribute__((__always_inline__, __nodebug__))
+_mm_maccsd_epi16(__m128i __A, __m128i __B, __m128i __C)
+{
+  return (__m128i)__builtin_ia32_vpmacsswd((__v8hi)__A, (__v8hi)__B, (__v4si)__C);
+}
+
+static __inline__ __m128i __attribute__((__always_inline__, __nodebug__))
+_mm_maccd_epi16(__m128i __A, __m128i __B, __m128i __C)
+{
+  return (__m128i)__builtin_ia32_vpmacswd((__v8hi)__A, (__v8hi)__B, (__v4si)__C);
+}
+
+static __inline__ __m128i __attribute__((__always_inline__, __nodebug__))
+_mm_maccs_epi32(__m128i __A, __m128i __B, __m128i __C)
+{
+  return (__m128i)__builtin_ia32_vpmacssdd((__v4si)__A, (__v4si)__B, (__v4si)__C);
+}
+
+static __inline__ __m128i __attribute__((__always_inline__, __nodebug__))
+_mm_macc_epi32(__m128i __A, __m128i __B, __m128i __C)
+{
+  return (__m128i)__builtin_ia32_vpmacsdd((__v4si)__A, (__v4si)__B, (__v4si)__C);
+}
+
+static __inline__ __m128i __attribute__((__always_inline__, __nodebug__))
+_mm_maccslo_epi32(__m128i __A, __m128i __B, __m128i __C)
+{
+  return (__m128i)__builtin_ia32_vpmacssdql((__v4si)__A, (__v4si)__B, (__v2di)__C);
+}
+
+static __inline__ __m128i __attribute__((__always_inline__, __nodebug__))
+_mm_macclo_epi32(__m128i __A, __m128i __B, __m128i __C)
+{
+  return (__m128i)__builtin_ia32_vpmacsdql((__v4si)__A, (__v4si)__B, (__v2di)__C);
+}
+
+static __inline__ __m128i __attribute__((__always_inline__, __nodebug__))
+_mm_maccshi_epi32(__m128i __A, __m128i __B, __m128i __C)
+{
+  return (__m128i)__builtin_ia32_vpmacssdqh((__v4si)__A, (__v4si)__B, (__v2di)__C);
+}
+
+static __inline__ __m128i __attribute__((__always_inline__, __nodebug__))
+_mm_macchi_epi32(__m128i __A, __m128i __B, __m128i __C)
+{
+  return (__m128i)__builtin_ia32_vpmacsdqh((__v4si)__A, (__v4si)__B, (__v2di)__C);
+}
+
+static __inline__ __m128i __attribute__((__always_inline__, __nodebug__))
+_mm_maddsd_epi16(__m128i __A, __m128i __B, __m128i __C)
+{
+  return (__m128i)__builtin_ia32_vpmadcsswd((__v8hi)__A, (__v8hi)__B, (__v4si)__C);
+}
+
+static __inline__ __m128i __attribute__((__always_inline__, __nodebug__))
+_mm_maddd_epi16(__m128i __A, __m128i __B, __m128i __C)
+{
+  return (__m128i)__builtin_ia32_vpmadcswd((__v8hi)__A, (__v8hi)__B, (__v4si)__C);
+}
+
+#endif /* __XOP__ */
+
+#endif /* __XOPINTRIN_H */
diff --git a/test/CodeGen/xop-builtins.c b/test/CodeGen/xop-builtins.c
new file mode 100644
index 0000000..9fe79e4
--- /dev/null
+++ b/test/CodeGen/xop-builtins.c
@@ -0,0 +1,66 @@
+// RUN: %clang_cc1 %s -O3 -triple=x86_64-apple-darwin -target-feature +xop -emit-llvm -o - | FileCheck %s
+
+// Don't include mm_malloc.h, it's system specific.
+#define __MM_MALLOC_H
+
+#include <x86intrin.h>
+
+__m128i test_mm_maccs_epi16(__m128i a, __m128i b, __m128i c) {
+  // CHECK: @llvm.x86.xop.vpmacssww
+  return _mm_maccs_epi16(a, b, c);
+}
+
+__m128i test_mm_macc_epi16(__m128i a, __m128i b, __m128i c) {
+  // CHECK: @llvm.x86.xop.vpmacsww
+  return _mm_macc_epi16(a, b, c);
+}
+
+__m128i test_mm_maccsd_epi16(__m128i a, __m128i b, __m128i c) {
+  // CHECK: @llvm.x86.xop.vpmacsswd
+  return _mm_maccsd_epi16(a, b, c);
+}
+
+__m128i test_mm_maccd_epi16(__m128i a, __m128i b, __m128i c) {
+  // CHECK: @llvm.x86.xop.vpmacswd
+  return _mm_maccd_epi16(a, b, c);
+}
+
+__m128i test_mm_maccs_epi32(__m128i a, __m128i b, __m128i c) {
+  // CHECK: @llvm.x86.xop.vpmacssdd
+  return _mm_maccs_epi32(a, b, c);
+}
+
+__m128i test_mm_macc_epi32(__m128i a, __m128i b, __m128i c) {
+  // CHECK: @llvm.x86.xop.vpmacsdd
+  return _mm_macc_epi32(a, b, c);
+}
+
+__m128i test_mm_maccslo_epi32(__m128i a, __m128i b, __m128i c) {
+  // CHECK: @llvm.x86.xop.vpmacssdql
+  return _mm_maccslo_epi32(a, b, c);
+}
+
+__m128i test_mm_macclo_epi32(__m128i a, __m128i b, __m128i c) {
+  // CHECK: @llvm.x86.xop.vpmacsdql
+  return _mm_macclo_epi32(a, b, c);
+}
+
+__m128i test_mm_maccshi_epi32(__m128i a, __m128i b, __m128i c) {
+  // CHECK: @llvm.x86.xop.vpmacssdqh
+  return _mm_maccshi_epi32(a, b, c);
+}
+
+__m128i test_mm_macchi_epi32(__m128i a, __m128i b, __m128i c) {
+  // CHECK: @llvm.x86.xop.vpmacsdqh
+  return _mm_macchi_epi32(a, b, c);
+}
+
+__m128i test_mm_maddsd_epi16(__m128i a, __m128i b, __m128i c) {
+  // CHECK: @llvm.x86.xop.vpmadcsswd
+  return _mm_maddsd_epi16(a, b, c);
+}
+
+__m128i test_mm_maddd_epi16(__m128i a, __m128i b, __m128i c) {
+  // CHECK: @llvm.x86.xop.vpmadcswd
+  return _mm_maddd_epi16(a, b, c);
+}