new testcase that condprop should handle. The PHI node becomes useless

after threading the branch, because both operands are the same value.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@22668 91177308-0d34-0410-b5e6-96231b3b80d8

diff --git a/test/Transforms/CondProp/phisimplify2.ll b/test/Transforms/CondProp/phisimplify2.ll
new file mode 100644 (file)
index 0000000..177dac5
--- /dev/null
+++ b/test/Transforms/CondProp/phisimplify2.ll
@@ -0,0 +1,36 @@
+; RUN: llvm-as < %s | opt -condprop | llvm-dis | not grep phi
+
+declare bool %foo()
+
+int %test(uint %C) {
+       %Val = call bool %foo()
+        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()