1; NOTE: Assertions have been autogenerated by utils/update_test_checks.py
2; Test CFG simplify removal of branch instructions.
3;
4; RUN: opt < %s -simplifycfg -simplifycfg-require-and-preserve-domtree=1 -S | FileCheck %s
5; RUN: opt < %s -passes=simplify-cfg -S | FileCheck %s
6
7define void @test1() {
8; CHECK-LABEL: @test1(
9; CHECK-NEXT:    ret void
10;
11  br label %1
12  ret void
13}
14
15define void @test2() {
16; CHECK-LABEL: @test2(
17; CHECK-NEXT:    ret void
18;
19  ret void
20  ret void
21}
22
23define void @test3(i1 %T) {
24; CHECK-LABEL: @test3(
25; CHECK-NEXT:    ret void
26;
27  br i1 %T, label %1, label %1
28  ret void
29}
30
31; Folding branch to a common destination.
32define void @test4_fold(i32 %a, i32 %b) {
33; CHECK-LABEL: @test4_fold(
34; CHECK-NEXT:    [[CMP1:%.*]] = icmp eq i32 [[A:%.*]], [[B:%.*]]
35; CHECK-NEXT:    [[CMP2:%.*]] = icmp ugt i32 [[A]], 0
36; CHECK-NEXT:    [[OR_COND:%.*]] = and i1 [[CMP1]], [[CMP2]]
37; CHECK-NEXT:    br i1 [[OR_COND]], label [[ELSE:%.*]], label [[UNTAKEN:%.*]]
38; CHECK:       else:
39; CHECK-NEXT:    call void @foo()
40; CHECK-NEXT:    ret void
41; CHECK:       untaken:
42; CHECK-NEXT:    ret void
43;
44  %cmp1 = icmp eq i32 %a, %b
45  br i1 %cmp1, label %taken, label %untaken
46
47taken:
48  %cmp2 = icmp ugt i32 %a, 0
49  br i1 %cmp2, label %else, label %untaken
50
51else:
52  call void @foo()
53  ret void
54
55untaken:
56  ret void
57}
58
59; Prefer a simplification based on a dominating condition rather than folding a
60; branch to a common destination.
61define void @test4_no_fold(i32 %a, i32 %b) {
62; CHECK-LABEL: @test4_no_fold(
63; CHECK-NEXT:  untaken:
64; CHECK-NEXT:    [[CMP1:%.*]] = icmp eq i32 [[A:%.*]], [[B:%.*]]
65; CHECK-NEXT:    ret void
66;
67  %cmp1 = icmp eq i32 %a, %b
68  br i1 %cmp1, label %taken, label %untaken
69
70taken:
71  %cmp2 = icmp ugt i32 %a, %b
72  br i1 %cmp2, label %else, label %untaken
73
74else:
75  call void @foo()
76  ret void
77
78untaken:
79  ret void
80}
81
82declare void @foo()
83
84; PR5795
85define void @test5(i32 %A) {
86; CHECK-LABEL: @test5(
87; CHECK-NEXT:    ret void
88;
89  switch i32 %A, label %return [
90  i32 2, label %1
91  i32 10, label %2
92  ]
93
94  ret void
95
96  ret void
97
98return:                                           ; preds = %entry
99  ret void
100}
101
102
103; PR14893
104define i8 @test6f() {
105; CHECK-LABEL: @test6f(
106; CHECK-NEXT:  bb0:
107; CHECK-NEXT:    [[R:%.*]] = alloca i8, align 1
108; CHECK-NEXT:    [[TMP:%.*]] = call i8 @test6g(i8* [[R]])
109; CHECK-NEXT:    [[TMP1:%.*]] = icmp eq i8 [[TMP]], 0
110; CHECK-NEXT:    [[TMP3:%.*]] = load i8, i8* [[R]], align 1
111; CHECK-NEXT:    [[TMP4:%.*]] = icmp eq i8 [[TMP3]], 1
112; CHECK-NEXT:    [[OR_COND:%.*]] = select i1 [[TMP1]], i1 true, i1 [[TMP4]]
113; CHECK-NEXT:    [[TMP6:%.*]] = select i1 [[OR_COND]], i8 0, i8 1
114; CHECK-NEXT:    ret i8 [[TMP6]]
115;
116
117bb0:
118  %r = alloca i8, align 1
119  %tmp = call i8 @test6g(i8* %r)
120  %tmp1 = icmp eq i8 %tmp, 0
121  br i1 %tmp1, label %bb2, label %bb1
122bb1:
123  %tmp3 = load i8, i8* %r, align 1, !range !2, !tbaa !10, !dbg !5
124  %tmp4 = icmp eq i8 %tmp3, 1
125  br i1 %tmp4, label %bb2, label %bb3
126bb2:
127  br label %bb3
128bb3:
129  %tmp6 = phi i8 [ 0, %bb2 ], [ 1, %bb1 ]
130  ret i8 %tmp6
131}
132declare i8 @test6g(i8*)
133
134!llvm.dbg.cu = !{!3}
135!llvm.module.flags = !{!8, !9}
136
137!0 = !{!10, !10, i64 0}
138!1 = !{!"foo"}
139!2 = !{i8 0, i8 2}
140!3 = distinct !DICompileUnit(language: DW_LANG_C99, file: !7, producer: "clang", isOptimized: false, runtimeVersion: 0, emissionKind: FullDebug, enums: !4, globals: !4)
141!4 = !{}
142!5 = !DILocation(line: 23, scope: !6)
143!6 = distinct !DISubprogram(name: "foo", scope: !3, file: !7, line: 1, type: !DISubroutineType(types: !4), isLocal: false, isDefinition: true, scopeLine: 1, flags: DIFlagPrototyped, isOptimized: false, unit: !3, retainedNodes: !4)
144!7 = !DIFile(filename: "foo.c", directory: "/")
145!8 = !{i32 2, !"Dwarf Version", i32 2}
146!9 = !{i32 2, !"Debug Info Version", i32 3}
147!10 = !{!"scalar type", !1}
148