| ; NOTE: Assertions have been autogenerated by update_test_checks.py |
| ; Test merging of blocks that only have PHI nodes in them |
| ; |
| ; RUN: opt < %s -simplifycfg -S | FileCheck %s |
| ; |
| |
| define i32 @test(i1 %a, i1 %b) { |
| ; CHECK-LABEL: @test( |
| ; CHECK: M: |
| ; CHECK-NEXT: [[DOT:%.*]] = select i1 %b, i32 0, i32 1 |
| ; CHECK-NEXT: [[W:%.*]] = select i1 %a, i32 2, i32 [[DOT]] |
| ; CHECK-NEXT: [[R:%.*]] = add i32 [[W]], 1 |
| ; CHECK-NEXT: ret i32 [[R]] |
| ; |
| 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 |
| } |
| |
