diff --git a/test/CodeGen/X86/lzcnt.ll b/test/CodeGen/X86/lzcnt.ll
new file mode 100644
index 00000000000..e5a55abf1ab
--- /dev/null
+++ b/test/CodeGen/X86/lzcnt.ll
@@ -0,0 +1,38 @@
+; RUN: llc < %s -march=x86-64 -mattr=+lzcnt | FileCheck %s
+
+define i32 @t1(i32 %x) nounwind  {
+	%tmp = tail call i32 @llvm.ctlz.i32( i32 %x )
+	ret i32 %tmp
+; CHECK: t1:
+; CHECK: lzcntl
+}
+
+declare i32 @llvm.ctlz.i32(i32) nounwind readnone
+
+define i16 @t2(i16 %x) nounwind  {
+	%tmp = tail call i16 @llvm.ctlz.i16( i16 %x )
+	ret i16 %tmp
+; CHECK: t2:
+; CHECK: lzcntw
+}
+
+declare i16 @llvm.ctlz.i16(i16) nounwind readnone
+
+define i64 @t3(i64 %x) nounwind  {
+	%tmp = tail call i64 @llvm.ctlz.i64( i64 %x )
+	ret i64 %tmp
+; CHECK: t3:
+; CHECK: lzcntq
+}
+
+declare i64 @llvm.ctlz.i64(i64) nounwind readnone
+
+define i8 @t4(i8 %x) nounwind  {
+	%tmp = tail call i8 @llvm.ctlz.i8( i8 %x )
+	ret i8 %tmp
+; CHECK: t4:
+; CHECK: lzcntw
+}
+
+declare i8 @llvm.ctlz.i8(i8) nounwind readnone
+