; Test merging of blocks that only have PHI nodes in them ; ; RUN: llvm-as < %s | opt -simplifycfg | llvm-dis | 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 }