[X86] Add CLWB intrinsic. clang part

Reviewers: RKSimon, zvi, igorb

Reviewed By: RKSimon

Subscribers: cfe-commits

Differential Revision: https://reviews.llvm.org/D38781

llvm-svn: 315607
diff --git a/clang/test/CodeGen/builtin-clwb.c b/clang/test/CodeGen/builtin-clwb.c
new file mode 100644
index 0000000..96d00a6
--- /dev/null
+++ b/clang/test/CodeGen/builtin-clwb.c
@@ -0,0 +1,9 @@
+// RUN: %clang_cc1 %s -ffreestanding -triple=x86_64-apple-darwin -target-feature +clwb  -emit-llvm -o - -Wall -Werror | FileCheck %s
+
+#include <x86intrin.h>
+
+void test_mm_clwb(const void *__m) {
+  //CHECK-LABEL: @test_mm_clwb
+  //CHECK: @llvm.x86.clwb
+  _mm_clwb(__m);
+}