diff options
Diffstat (limited to 'llvm/test/Transforms/SimplifyCFG/PhiBlockMerge.ll')
| -rw-r--r-- | llvm/test/Transforms/SimplifyCFG/PhiBlockMerge.ll | 29 |
1 files changed, 29 insertions, 0 deletions
diff --git a/llvm/test/Transforms/SimplifyCFG/PhiBlockMerge.ll b/llvm/test/Transforms/SimplifyCFG/PhiBlockMerge.ll new file mode 100644 index 00000000000..85b98706018 --- /dev/null +++ b/llvm/test/Transforms/SimplifyCFG/PhiBlockMerge.ll @@ -0,0 +1,29 @@ +; 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 +} + |
