xref: /llvm-project/llvm/test/Analysis/RegionInfo/outgoing_edge.ll (revision 50153213c80286c6c91da4612aaf234cc6438c63)
1; REQUIRES: asserts
2; RUN: opt < %s -passes='print<regions>' 2>&1 | FileCheck %s
3
4; While working on improvements to the region info analysis, this test
5; case caused an incorrect region bb2 => bb3 to be detected. It is incorrect
6; because bb2 has an outgoing edge to bb4. This is interesting because
7; bb2 dom bb3 and bb3 pdom bb2, which should have been enough to prevent incoming
8; forward edges into the region and outgoing forward edges from the region.
9
10define void @meread_() nounwind {
11bb:
12   br label %bb1
13
14bb1:                                              ; preds = %bb4, %bb
15   br label %bb2
16
17bb2:                                              ; preds = %bb1
18  br i1 true, label %bb3, label %bb4
19
20bb3:                                              ; preds = %bb2
21  br i1 true, label %bb4, label %bb5
22
23bb4:                                              ; preds = %bb3, %bb2
24   br label %bb1
25
26bb5:                                              ; preds = %bb3
27   ret void
28 }
29
30; CHECK:      [0] bb => <Function Return>
31; CHECK-NEXT:   [1] bb1 => bb5
32; CHECK-NEXT: End region tree
33