1 files changed, 22 insertions, 0 deletions
diff --git a/test/Transforms/SimplifyCFG/PhiBlockMerge.ll b/test/Transforms/SimplifyCFG/PhiBlockMerge.ll
new file mode 100644
index 0000000..a648efd
--- /dev/null
+++ b/test/Transforms/SimplifyCFG/PhiBlockMerge.ll
@@ -0,0 +1,22 @@
+; Test merging of blocks that only have PHI nodes in them
+;
+; RUN: opt < %s -simplifycfg -S | not grep N:
+;
+
+define i32 @test(i1 %a, i1 %b) {
+; <label>:0
+        br i1 %a, label %M, label %O
+O:              ; preds = %0
+        br i1 %b, label %N, label %Q
+Q:              ; preds = %O
+        br label %N
+N:              ; preds = %Q, %O
+        ; This block should be foldable into M
+        %Wp = phi i32 [ 0, %O ], [ 1, %Q ]              ; <i32> [#uses=1]
+        br label %M
+M:              ; preds = %N, %0
+        %W = phi i32 [ %Wp, %N ], [ 2, %0 ]             ; <i32> [#uses=1]
+        %R = add i32 %W, 1              ; <i32> [#uses=1]
+        ret i32 %R
+}
+