1; REQUIRES: asserts
2; RUN: opt -loop-unswitch -disable-output -stats -info-output-file - < %s | FileCheck --check-prefix=STATS %s
3; RUN: opt -S -loop-unswitch -verify-loop-info -verify-dom-info < %s | FileCheck %s
4
5; STATS: 1 loop-simplify - Number of pre-header or exit blocks inserted
6; STATS: 2 loop-unswitch - Number of switches unswitched
7
8; CHECK:      %1 = icmp eq i32 %c, 1
9; CHECK-NEXT: br i1 %1, label %.split.us, label %..split_crit_edge
10
11; CHECK:      ..split_crit_edge:                                ; preds = %0
12; CHECK-NEXT:   br label %.split
13
14; CHECK:      .split.us:                                        ; preds = %0
15; CHECK-NEXT:   br label %loop_begin.us
16
17; CHECK:      loop_begin.us:                                    ; preds = %loop_begin.backedge.us, %.split.us
18; CHECK-NEXT:   %var_val.us = load i32* %var
19; CHECK-NEXT:   switch i32 1, label %default.us-lcssa.us [
20; CHECK-NEXT:     i32 1, label %inc.us
21
22; CHECK:      inc.us:                                           ; preds = %loop_begin.us
23; CHECK-NEXT:   call void @incf() [[NOR_NUW:#[0-9]+]]
24; CHECK-NEXT:   br label %loop_begin.backedge.us
25
26; CHECK:      .split:                                           ; preds = %..split_crit_edge
27; CHECK-NEXT:   %2 = icmp eq i32 %c, 2
28; CHECK-NEXT:   br i1 %2, label %.split.split.us, label %.split..split.split_crit_edge
29
30; CHECK:      .split..split.split_crit_edge:                    ; preds = %.split
31; CHECK-NEXT:   br label %.split.split
32
33; CHECK:      .split.split.us:                                  ; preds = %.split
34; CHECK-NEXT:   br label %loop_begin.us1
35
36; CHECK:      loop_begin.us1:                                   ; preds = %loop_begin.backedge.us5, %.split.split.us
37; CHECK-NEXT:   %var_val.us2 = load i32* %var
38; CHECK-NEXT:   switch i32 2, label %default.us-lcssa.us-lcssa.us [
39; CHECK-NEXT:     i32 1, label %inc.us4
40; CHECK-NEXT:     i32 2, label %dec.us3
41; CHECK-NEXT:   ]
42
43; CHECK:      dec.us3:                                          ; preds = %loop_begin.us1
44; CHECK-NEXT:   call void @decf() [[NOR_NUW]]
45; CHECK-NEXT:   br label %loop_begin.backedge.us5
46
47; CHECK:      .split.split:                                     ; preds = %.split..split.split_crit_edge
48; CHECK-NEXT:   br label %loop_begin
49
50; CHECK:      loop_begin:                                       ; preds = %loop_begin.backedge, %.split.split
51; CHECK-NEXT:   %var_val = load i32* %var
52; CHECK-NEXT:   switch i32 %c, label %default.us-lcssa.us-lcssa [
53; CHECK-NEXT:     i32 1, label %inc
54; CHECK-NEXT:     i32 2, label %dec
55; CHECK-NEXT:   ]
56
57; CHECK:      inc:                                              ; preds = %loop_begin
58; CHECK-NEXT:   br i1 true, label %us-unreachable.us-lcssa, label %inc.split
59
60; CHECK:      dec:                                              ; preds = %loop_begin
61; CHECK-NEXT:   br i1 true, label %us-unreachable6, label %dec.split
62
63define i32 @test(i32* %var) {
64  %mem = alloca i32
65  store i32 2, i32* %mem
66  %c = load i32* %mem
67
68  br label %loop_begin
69
70loop_begin:
71
72  %var_val = load i32* %var
73
74  switch i32 %c, label %default [
75      i32 1, label %inc
76      i32 2, label %dec
77  ]
78
79inc:
80  call void @incf() noreturn nounwind
81  br label %loop_begin
82dec:
83  call void @decf() noreturn nounwind
84  br label %loop_begin
85default:
86  br label %loop_exit
87loop_exit:
88  ret i32 0
89}
90
91declare void @incf() noreturn
92declare void @decf() noreturn
93
94; CHECK: attributes #0 = { noreturn }
95; CHECK: attributes [[NOR_NUW]] = { noreturn nounwind }
96