1; RUN: opt < %s -simplifycfg -S | FileCheck %s
2
3; Test that we can thread a simple known condition through switch statements.
4
5declare void @foo1()
6
7declare void @foo2()
8
9declare void @DEAD()
10
11define void @test1(i32 %V) {
12        switch i32 %V, label %A [
13                 i32 4, label %T
14                 i32 17, label %Done
15                 i32 1234, label %A
16        ]
17;; V == 4 if we get here.
18T:              ; preds = %0
19        call void @foo1( )
20        ;; This switch is always statically determined.
21        switch i32 %V, label %A2 [
22                 i32 4, label %B
23                 i32 17, label %C
24                 i32 42, label %C
25        ]
26A2:             ; preds = %T
27        call void @DEAD( )
28        call void @DEAD( )
29        ;; always true
30        %cond2 = icmp eq i32 %V, 4              ; <i1> [#uses=1]
31        br i1 %cond2, label %Done, label %C
32A:              ; preds = %0, %0
33        call void @foo1( )
34        ;; always true
35        %cond = icmp ne i32 %V, 4               ; <i1> [#uses=1]
36        br i1 %cond, label %Done, label %C
37Done:           ; preds = %B, %A, %A2, %0
38        ret void
39B:              ; preds = %T
40        call void @foo2( )
41        ;; always true
42        %cond3 = icmp eq i32 %V, 4              ; <i1> [#uses=1]
43        br i1 %cond3, label %Done, label %C
44C:              ; preds = %B, %A, %A2, %T, %T
45        call void @DEAD( )
46        ret void
47
48; CHECK-LABEL: @test1(
49; CHECK-NEXT:    switch i32 %V, label %A [
50; CHECK-NEXT:    i32 4, label %T
51; CHECK-NEXT:    i32 17, label %Done
52; CHECK-NEXT:    ]
53; CHECK:       T:
54; CHECK-NEXT:    call void @foo1()
55; CHECK-NEXT:    call void @foo2()
56; CHECK-NEXT:    br label %Done
57; CHECK:       A:
58; CHECK-NEXT:    call void @foo1()
59; CHECK-NEXT:    br label %Done
60; CHECK:       Done:
61; CHECK-NEXT:    ret void
62}
63
64define void @test2(i32 %V) {
65        switch i32 %V, label %A [
66                 i32 4, label %T
67                 i32 17, label %D
68                 i32 1234, label %E
69        ]
70;; V != 4, 17, 1234 here.
71A:              ; preds = %0
72        call void @foo1( )
73        ;; This switch is always statically determined.
74        switch i32 %V, label %E [
75                 i32 4, label %C
76                 i32 17, label %C
77                 i32 42, label %D
78        ]
79;; unreacahble.
80C:              ; preds = %A, %A
81        call void @DEAD( )
82        ret void
83T:              ; preds = %0
84        call void @foo1( )
85        call void @foo1( )
86        ret void
87D:              ; preds = %A, %0
88        call void @foo1( )
89        ret void
90E:              ; preds = %A, %0
91        ret void
92
93; CHECK-LABEL: @test2(
94; CHECK-NEXT:    switch i32 %V, label %A [
95; CHECK-NEXT:    i32 4, label %T
96; CHECK-NEXT:    i32 17, label %D
97; CHECK-NEXT:    i32 1234, label %E
98; CHECK-NEXT:    ]
99; CHECK:       A:
100; CHECK-NEXT:    call void @foo1()
101; CHECK-NEXT:    [[COND:%.*]] = icmp eq i32 %V, 42
102; CHECK-NEXT:    br i1 [[COND]], label %D, label %E
103; CHECK:       T:
104; CHECK-NEXT:    call void @foo1()
105; CHECK-NEXT:    call void @foo1()
106; CHECK-NEXT:    ret void
107; CHECK:       D:
108; CHECK-NEXT:    call void @foo1()
109; CHECK-NEXT:    ret void
110; CHECK:       E:
111; CHECK-NEXT:    ret void
112}
113
114