xref: /llvm-project/llvm/test/Transforms/LowerSwitch/condition-phi-unreachable-default.ll (revision abb9f9fa06ef22be2b0287b9047d5cfed71d91d4)
1; RUN: opt < %s -passes=lower-switch -S | FileCheck %s
2
3; This test verifies -lower-switch does not crash when an removing an
4; unreachable default branch causes a PHI node used as the switch
5; condition to be erased.
6
7define void @f() local_unnamed_addr {
8entry:
9  br label %sw.epilog
10
11sw.epilog:                                        ; preds = %sw.epilog.outer, %for.body
12  %i = phi i32 [ undef, %for.body ], [ 0, %entry ]
13  br i1 true, label %for.body, label %for.end
14
15for.body:                                         ; preds = %sw.epilog
16  switch i32 %i, label %sw.epilog [
17    i32 0, label %sw.epilog.outer.backedge.loopexit
18    i32 1, label %sw.epilog.outer.backedge
19  ]
20
21sw.epilog.outer.backedge.loopexit:                ; preds = %for.body
22  br label %for.end
23
24sw.epilog.outer.backedge:                         ; preds = %for.body
25  unreachable
26
27for.end:                                          ; preds = %sw.epilog
28  ret void
29}
30
31; The phi and the switch should both be eliminated.
32; CHECK: @f()
33; CHECK: sw.epilog:
34; CHECK-NOT: phi
35; CHECK: for.body:
36; CHECK-NOT: switch
37