xref: /llvm-project/llvm/test/Transforms/LoopSimplifyCFG/irreducible_cfg.ll (revision a3712e8754578a09436cf745f1036c2355287f6e)
1; NOTE: Assertions have been autogenerated by utils/update_test_checks.py
2; REQUIRES: asserts
3; RUN: opt -S -enable-loop-simplifycfg-term-folding=true -passes='require<domtree>,loop(loop-simplifycfg)' -debug-only=loop-simplifycfg -verify-loop-info -verify-dom-info -verify-loop-lcssa 2>&1 < %s | FileCheck %s
4; RUN: opt -S -enable-loop-simplifycfg-term-folding=true -passes=loop-simplifycfg -verify-memoryssa -debug-only=loop-simplifycfg -verify-loop-info -verify-dom-info -verify-loop-lcssa 2>&1 < %s | FileCheck %s
5
6target datalayout = "e-m:e-i64:64-f80:128-n8:16:32:64-S128-ni:1"
7
8; This test has irreducible CFG, and RPO may be the following:
9; Header, Dead, Irreducible2, Latch, Irreducible3, Irreducible1.
10; As result, we will process Irreducible2 before its predecessor Irreducible1.
11; The current algorithm gets confused in this case. We may support irreducible
12; CFG in the future.
13define void @irreducible_cfg(i1 %cond) {
14; CHECK-LABEL: @irreducible_cfg(
15; CHECK-NEXT:  entry:
16; CHECK-NEXT:    br label [[HEADER:%.*]]
17; CHECK:       header:
18; CHECK-NEXT:    br i1 false, label [[DEAD:%.*]], label [[IRREDUCIBLE1:%.*]]
19; CHECK:       dead:
20; CHECK-NEXT:    br label [[IRREDUCIBLE2:%.*]]
21; CHECK:       irreducible2:
22; CHECK-NEXT:    br i1 [[COND:%.*]], label [[LATCH:%.*]], label [[IRREDUCIBLE3:%.*]]
23; CHECK:       latch:
24; CHECK-NEXT:    br label [[HEADER]]
25; CHECK:       irreducible3:
26; CHECK-NEXT:    br label [[IRREDUCIBLE1]]
27; CHECK:       irreducible1:
28; CHECK-NEXT:    br label [[IRREDUCIBLE2]]
29;
30entry:
31  br label %header
32
33header:                                             ; preds = %latch, %entry
34  br i1 false, label %dead, label %irreducible1
35
36dead:                                          ; preds = %header
37  br label %irreducible2
38
39irreducible2:                                             ; preds = %irreducible1, %dead
40  br i1 %cond, label %latch, label %irreducible3
41
42latch:                                         ; preds = %irreducible2
43  br label %header
44
45irreducible3:                                           ; preds = %irreducible2
46  br label %irreducible1
47
48irreducible1:                                          ; preds = %irreducible3, %header
49  br label %irreducible2
50}
51