xref: /llvm-project/llvm/test/Analysis/UniformityAnalysis/AMDGPU/irreducible/branch-outside.ll (revision 4d081560cd3b6ac114aee15f50480dd978b55a44)
1; RUN: opt %s -mtriple amdgcn-- -passes='print<uniformity>' -disable-output 2>&1 | FileCheck %s
2
3; CHECK=LABEL: UniformityInfo for function 'basic':
4; CHECK: CYCLES ASSSUMED DIVERGENT:
5; CHECK:   depth=1: entries(P T) Q
6define amdgpu_kernel void @basic(i32 %a, i32 %b, i32 %c) {
7entry:
8 %cond.uni = icmp slt i32 %a, 0
9 %tid = call i32 @llvm.amdgcn.workitem.id.x()
10 %cond.div = icmp slt i32 %tid, 0
11 br i1 %cond.div, label %T, label %P
12
13P:
14; CHECK:   DIVERGENT:   %pp.phi =
15; CHECK: DIVERGENT:      %pp =
16  %pp.phi  = phi i32 [ %a, %entry], [ %b, %T ]
17  %pp = add i32 %b, 1
18  br label %Q
19
20Q:
21; CHECK: DIVERGENT:   %qq =
22; CHECK:   DIVERGENT:   %qq.div =
23  %qq = add i32 %b, 1
24  %qq.div = add i32 %pp.phi, 1
25  br i1 %cond.uni, label %T, label %exit
26
27T:
28; CHECK:   DIVERGENT:   %t.phi =
29; CHECK: DIVERGENT:     %tt =
30  %t.phi = phi i32 [ %qq, %Q ], [ %a, %entry ]
31  %tt = add i32 %b, 1
32  br label %P
33
34exit:
35; CHECK-NOT: DIVERGENT:     %ee =
36  %ee = add i32 %b, 1
37  ret void
38}
39
40; CHECK=LABEL: UniformityInfo for function 'nested':
41; CHECK: CYCLES ASSSUMED DIVERGENT:
42; CHECK:  depth=1: entries(P T) Q A C B
43define amdgpu_kernel void @nested(i32 %a, i32 %b, i32 %c) {
44entry:
45 %cond.uni = icmp slt i32 %a, 0
46 %tid = call i32 @llvm.amdgcn.workitem.id.x()
47 %cond.div = icmp slt i32 %tid, 0
48 br i1 %cond.div, label %T, label %P
49
50P:
51 %pp.phi  = phi i32 [ %a, %entry], [ %b, %T ]
52 %pp = add i32 %b, 1
53 br i1 %cond.uni, label %B, label %Q
54
55Q:
56  %qq = add i32 %b, 1
57  br i1 %cond.uni, label %T, label %exit
58
59A:
60  %aa = add i32 %b, 1
61  br label %B
62
63B:
64  %bb = add i32 %b, 1
65  br label %C
66
67C:
68  %cc = add i32 %b, 1
69  br i1 %cond.uni, label %Q, label %A
70
71T:
72  %t.phi = phi i32 [ %qq, %Q ], [ %a, %entry ]
73  %tt = add i32 %b, 1
74  br i1 %cond.uni, label %A, label %P
75
76exit:
77  %ee = add i32 %b, 1
78  ret void
79}
80
81; Just make sure that this does not asert. It is important that Q is recognized
82; as the header of the outermost cycle. The incorrect assert was exercised by
83; this hierarchy:
84;
85; CycleInfo for function: irreducible_outer_cycle
86;    depth=1: entries(Q R) C B D
87;        depth=2: entries(R) C B D
88;            depth=3: entries(B) D
89;
90; CHECK-LABEL: UniformityInfo for function 'irreducible_outer_cycle':
91; CHECK: CYCLES ASSSUMED DIVERGENT:
92; CHECK:  depth=1: entries(Q R) C B D
93define void @irreducible_outer_cycle(i1 %c1, i1 %c2, i1 %c3) {
94entry:
95  br i1 %c1, label %P, label %Q
96
97P:
98  br i1 false, label %Q, label %R
99
100Q:
101  br label %R
102
103R:
104  br i1 false, label %Q, label %B
105
106B:
107  br i1 false, label %C, label %D
108
109D:
110  br label %B
111
112C:
113  br i1 false, label %R, label %exit
114
115exit:
116  ret void
117}
118
119declare i32 @llvm.amdgcn.workitem.id.x() #0
120