add a testcase nate requested

llvm-svn: 22663

1 files changed, 33 insertions, 0 deletions

diff --git a/llvm/test/Regression/Transforms/CondProp/phisimplify.ll b/llvm/test/Regression/Transforms/CondProp/phisimplify.ll
new file mode 100644
index 00000000000..818bcab40d2
--- /dev/null
+++ b/llvm/test/Regression/Transforms/CondProp/phisimplify.ll
@@ -0,0 +1,33 @@
+; RUN: llvm-as < %s | opt -condprop | llvm-dis | not grep phi
+
+int %test(uint %C, bool %Val) {
+        switch uint %C, label %T1 [
+                 uint 4, label %T2
+                 uint 17, label %T3
+        ]
+T1:
+	call void %a()
+	br label %Cont
+T2:
+	call void %b()
+	br label %Cont
+T3:
+	call void %c()
+	br label %Cont
+
+Cont:
+	;; PHI becomes dead after threading T2
+	%C2 = phi bool [%Val, %T1], [true, %T2], [%Val, %T3]
+	br bool %C2, label %L2, label %F2
+L2:
+	call void %d()
+	ret int 17
+F2:
+	call void %e()
+	ret int 1
+}
+declare void %a()
+declare void %b()
+declare void %c()
+declare void %d()
+declare void %e()