diff options
Diffstat (limited to 'llvm/test/Transforms/SimpleLoopUnswitch/nontrivial-unswitch.ll')
| -rw-r--r-- | llvm/test/Transforms/SimpleLoopUnswitch/nontrivial-unswitch.ll | 30 |
1 files changed, 30 insertions, 0 deletions
diff --git a/llvm/test/Transforms/SimpleLoopUnswitch/nontrivial-unswitch.ll b/llvm/test/Transforms/SimpleLoopUnswitch/nontrivial-unswitch.ll index 51cdebe70e0..651ba19c427 100644 --- a/llvm/test/Transforms/SimpleLoopUnswitch/nontrivial-unswitch.ll +++ b/llvm/test/Transforms/SimpleLoopUnswitch/nontrivial-unswitch.ll @@ -2350,3 +2350,33 @@ loop_exit: ; CHECK-NEXT: %[[LCSSA:.*]] = phi i32 [ %[[V]], %loop_begin ] ; CHECK-NEXT: ret i32 %[[LCSSA]] } + +; Negative test: we do not switch when the loop contains unstructured control +; flows as it would significantly complicate the process as novel loops might +; be formed, etc. +define void @test_no_unswitch_unstructured_cfg(i1* %ptr, i1 %cond) { +; CHECK-LABEL: @test_no_unswitch_unstructured_cfg( +entry: + br label %loop_begin + +loop_begin: + br i1 %cond, label %loop_left, label %loop_right + +loop_left: + %v1 = load i1, i1* %ptr + br i1 %v1, label %loop_right, label %loop_merge + +loop_right: + %v2 = load i1, i1* %ptr + br i1 %v2, label %loop_left, label %loop_merge + +loop_merge: + %v3 = load i1, i1* %ptr + br i1 %v3, label %loop_latch, label %loop_exit + +loop_latch: + br label %loop_begin + +loop_exit: + ret void +} |
