Add testcase for new feature for simplifycfg pass

llvm-svn: 5697

test/Regression/Transforms/SimplifyCFG/PhiBlockMerge.ll

@@ -0,0 +1,26 @@
+; Test merging of blocks that only have PHI nodes in them
+;
+; RUN: if as < %s | opt -simplifycfg | dis | grep 'N:'
+; RUN: then exit 1
+; RUN: else exit 0
+; RUN: fi
+;
+
+int %test(bool %a, bool %b) {
+        br bool %a, label %M, label %O
+
+O:
+	br bool %b, label %N, label %Q
+Q:
+	br label %N
+N:
+	%Wp = phi int [0, %O], [1, %Q]
+	; This block should be foldable into M
+	br label %M
+
+M:
+	%W = phi int [%Wp, %N], [2, %0]
+	%R = add int %W, 1
+	ret int %R
+}
+