1 ; NOTE: Assertions have been autogenerated by update_test_checks.py 2 ; Test merging of blocks that only have PHI nodes in them 3 ; 4 ; RUN: opt < %s -simplifycfg -S | FileCheck %s 5 ; 6 7 define i32 @test(i1 %a, i1 %b) { 8 ; CHECK-LABEL: @test( 9 ; CHECK: M: 10 ; CHECK-NEXT: [[DOT:%.*]] = select i1 %b, i32 0, i32 1 11 ; CHECK-NEXT: [[W:%.*]] = select i1 %a, i32 2, i32 [[DOT]] 12 ; CHECK-NEXT: [[R:%.*]] = add i32 [[W]], 1 13 ; CHECK-NEXT: ret i32 [[R]] 14 ; 15 br i1 %a, label %M, label %O 16 O: ; preds = %0 17 br i1 %b, label %N, label %Q 18 Q: ; preds = %O 19 br label %N 20 N: ; preds = %Q, %O 21 ; This block should be foldable into M 22 %Wp = phi i32 [ 0, %O ], [ 1, %Q ] ; <i32> [#uses=1] 23 br label %M 24 M: ; preds = %N, %0 25 %W = phi i32 [ %Wp, %N ], [ 2, %0 ] ; <i32> [#uses=1] 26 %R = add i32 %W, 1 ; <i32> [#uses=1] 27 ret i32 %R 28 } 29 30
