diff --git a/test/CodeGen/X86/red-zone.ll b/test/CodeGen/X86/red-zone.ll
new file mode 100644
index 00000000000..60e16b05ca7
--- /dev/null
+++ b/test/CodeGen/X86/red-zone.ll
@@ -0,0 +1,13 @@
+; RUN: llvm-as < %s | llc -march=x86-64 > %t
+; RUN: not grep subq %t
+; RUN: not grep addq %t
+; RUN: grep {\\-4(%%rsp)} %t | count 2
+; RUN: llvm-as < %s | llc -march=x86-64 -disable-red-zone > %t
+; RUN: grep subq %t | count 1
+; RUN: grep addq %t | count 1
+
+define x86_fp80 @f0(float %f) nounwind readnone {
+entry:
+	%0 = fpext float %f to x86_fp80		; <x86_fp80> [#uses=1]
+	ret x86_fp80 %0
+}