1; NOTE: Assertions have been autogenerated by utils/update_test_checks.py
2; RUN: opt -passes='loop-mssa(simple-loop-unswitch<nontrivial>),loop-mssa(simple-loop-unswitch<nontrivial>),verify<loops>' -S < %s | FileCheck %s
3
4; Below bugs have caused endless unswitch.
5;
6; https://bugs.llvm.org/show_bug.cgi?id=50279
7; https://bugs.llvm.org/show_bug.cgi?id=50302
8;
9; This test's loop should be unswitched only one time even though we run
10; SimpleLoopUnswitch pass two times.
11
12@a = dso_local local_unnamed_addr global i32 0, align 4
13@c = dso_local local_unnamed_addr global i32 0, align 4
14@b = dso_local local_unnamed_addr global i8 0, align 1
15
16; Function Attrs: nofree norecurse nosync nounwind uwtable
17define dso_local void @d() {
18; CHECK-LABEL: @d(
19; CHECK-NEXT:  entry:
20; CHECK-NEXT:    br label [[FOR_COND:%.*]]
21; CHECK:       for.cond:
22; CHECK-NEXT:    br i1 false, label [[FOR_END:%.*]], label [[FOR_COND]]
23; CHECK:       for.end:
24; CHECK-NEXT:    [[TMP0:%.*]] = load i16, i16* null, align 2
25; CHECK-NEXT:    [[TMP1:%.*]] = icmp eq i16 [[TMP0]], 0
26; CHECK-NEXT:    br i1 [[TMP1]], label [[FOR_END_SPLIT:%.*]], label [[FOR_END_SPLIT_US:%.*]]
27; CHECK:       for.end.split.us:
28; CHECK-NEXT:    br label [[G_US:%.*]]
29; CHECK:       g.us:
30; CHECK-NEXT:    br label [[G_SPLIT_US6:%.*]]
31; CHECK:       for.cond1.us1:
32; CHECK-NEXT:    [[TMP2:%.*]] = load i16, i16* null, align 2
33; CHECK-NEXT:    [[TOBOOL4_NOT_US:%.*]] = icmp eq i16 [[TMP2]], 0
34; CHECK-NEXT:    br i1 [[TOBOOL4_NOT_US]], label [[FOR_COND5_PREHEADER_US4:%.*]], label [[G_LOOPEXIT_US:%.*]]
35; CHECK:       for.cond5.us2:
36; CHECK-NEXT:    br i1 false, label [[FOR_COND1_LOOPEXIT_US5:%.*]], label [[FOR_INC_US3:%.*]]
37; CHECK:       for.inc.us3:
38; CHECK-NEXT:    store i8 0, i8* @b, align 1
39; CHECK-NEXT:    br label [[FOR_COND5_US2:%.*]]
40; CHECK:       for.cond5.preheader.us4:
41; CHECK-NEXT:    br label [[FOR_COND5_US2]]
42; CHECK:       for.cond1.loopexit.us5:
43; CHECK-NEXT:    br label [[FOR_COND1_US1:%.*]], !llvm.loop [[LOOP0:![0-9]+]]
44; CHECK:       g.loopexit.us:
45; CHECK-NEXT:    br label [[G_US]]
46; CHECK:       g.split.us6:
47; CHECK-NEXT:    br label [[FOR_COND1_US1]]
48; CHECK:       for.end.split:
49; CHECK-NEXT:    br label [[G:%.*]]
50; CHECK:       g.loopexit:
51; CHECK-NEXT:    br label [[G]], !llvm.loop [[LOOP2:![0-9]+]]
52; CHECK:       g:
53; CHECK-NEXT:    [[TMP3:%.*]] = load i16, i16* null, align 2
54; CHECK-NEXT:    [[TMP4:%.*]] = icmp eq i16 [[TMP3]], 0
55; CHECK-NEXT:    br i1 [[TMP4]], label [[G_SPLIT_US:%.*]], label [[G_SPLIT:%.*]]
56; CHECK:       g.split.us:
57; CHECK-NEXT:    br label [[FOR_COND1_US:%.*]]
58; CHECK:       for.cond1.us:
59; CHECK-NEXT:    br label [[FOR_COND5_PREHEADER_US:%.*]]
60; CHECK:       for.cond5.us:
61; CHECK-NEXT:    br i1 false, label [[FOR_COND1_LOOPEXIT_US:%.*]], label [[FOR_INC_US:%.*]]
62; CHECK:       for.inc.us:
63; CHECK-NEXT:    store i8 0, i8* @b, align 1
64; CHECK-NEXT:    br label [[FOR_COND5_US:%.*]]
65; CHECK:       for.cond5.preheader.us:
66; CHECK-NEXT:    br label [[FOR_COND5_US]]
67; CHECK:       for.cond1.loopexit.us:
68; CHECK-NEXT:    br label [[FOR_COND1_US]]
69; CHECK:       g.split:
70; CHECK-NEXT:    br label [[FOR_COND1:%.*]]
71; CHECK:       for.cond1.loopexit:
72; CHECK-NEXT:    br label [[FOR_COND1]], !llvm.loop [[LOOP0]]
73; CHECK:       for.cond1:
74; CHECK-NEXT:    [[TMP5:%.*]] = load i16, i16* null, align 2
75; CHECK-NEXT:    [[TOBOOL4_NOT:%.*]] = icmp eq i16 [[TMP5]], 0
76; CHECK-NEXT:    br i1 [[TOBOOL4_NOT]], label [[FOR_COND5_PREHEADER:%.*]], label [[G_LOOPEXIT:%.*]]
77; CHECK:       for.cond5.preheader:
78; CHECK-NEXT:    br label [[FOR_COND5:%.*]]
79; CHECK:       for.cond5:
80; CHECK-NEXT:    br i1 false, label [[FOR_COND1_LOOPEXIT:%.*]], label [[FOR_INC:%.*]]
81; CHECK:       for.inc:
82; CHECK-NEXT:    store i8 0, i8* @b, align 1
83; CHECK-NEXT:    br label [[FOR_COND5]]
84;
85entry:
86  br label %for.cond
87
88for.cond:                                         ; preds = %for.cond, %entry
89  br i1 false, label %for.end, label %for.cond
90
91for.end:                                          ; preds = %for.cond
92  br label %g
93
94g:                                                ; preds = %for.cond1, %for.end
95  br label %for.cond1
96
97for.cond1:                                        ; preds = %for.cond5, %g
98  %0 = load i16, i16* null, align 2
99  %tobool4.not = icmp eq i16 %0, 0
100  br i1 %tobool4.not, label %for.cond5, label %g
101
102for.cond5:                                        ; preds = %for.inc, %for.cond1
103  br i1 false, label %for.cond1, label %for.inc
104
105for.inc:                                          ; preds = %for.cond5
106  store i8 0, i8* @b, align 1
107  br label %for.cond5
108}
109