Add a redundant PHI testcase for SSAUpdater to go with svn r100047.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@100050 91177308-0d34-0410-b5e6-96231b3b80d8

diff --git a/test/Transforms/GVN/2010-03-31-RedundantPHIs.ll b/test/Transforms/GVN/2010-03-31-RedundantPHIs.ll
new file mode 100644 (file)
index 0000000..066e303
--- /dev/null
+++ b/test/Transforms/GVN/2010-03-31-RedundantPHIs.ll
@@ -0,0 +1,46 @@
+; RUN: opt < %s -gvn -enable-full-load-pre -S | FileCheck %s
+
+define i8* @cat(i8* %s1, ...) nounwind {
+entry:
+  br i1 undef, label %bb, label %bb3
+
+bb:                                               ; preds = %entry
+  unreachable
+
+bb3:                                              ; preds = %entry
+  store i8* undef, i8** undef, align 4
+  br i1 undef, label %bb5, label %bb6
+
+bb5:                                              ; preds = %bb3
+  unreachable
+
+bb6:                                              ; preds = %bb3
+  br label %bb12
+
+bb8:                                              ; preds = %bb12
+  br i1 undef, label %bb9, label %bb10
+
+bb9:                                              ; preds = %bb8
+  %0 = load i8** undef, align 4                   ; <i8*> [#uses=0]
+  %1 = load i8** undef, align 4                   ; <i8*> [#uses=0]
+  br label %bb11
+
+bb10:                                             ; preds = %bb8
+  br label %bb11
+
+bb11:                                             ; preds = %bb10, %bb9
+; CHECK: bb11:
+; CHECK: phi
+; CHECK-NOT: phi
+  br label %bb12
+
+bb12:                                             ; preds = %bb11, %bb6
+; CHECK: bb12:
+; CHECK: phi
+; CHECK-NOT: phi
+  br i1 undef, label %bb8, label %bb13
+
+bb13:                                             ; preds = %bb12
+; CHECK: bb13:
+  ret i8* undef
+}