1; NOTE: Assertions have been autogenerated by utils/update_test_checks.py
2; RUN: opt < %s -latesimplifycfg -S | FileCheck %s
3
4; PR10131
5
6target datalayout = "e-p:32:32:32-i1:8:8-i8:8:8-i16:16:16-i32:32:32-i64:32:64-f32:32:32-f64:32:64-v64:64:64-v128:128:128-a0:0:64-f80:32:32-n8:16:32"
7target triple = "i386-pc-linux-gnu"
8
9define i32 @t(i32 %m) nounwind readnone {
10; CHECK-LABEL: @t(
11; CHECK-NEXT:  entry:
12; CHECK-NEXT:    [[SWITCH:%.*]] = icmp ult i32 [[M:%.*]], 4
13; CHECK-NEXT:    [[M_:%.*]] = select i1 [[SWITCH]], i32 [[M]], i32 4
14; CHECK-NEXT:    ret i32 [[M_]]
15;
16entry:
17  switch i32 %m, label %sw.bb4 [
18  i32 0, label %sw.bb0
19  i32 1, label %sw.bb1
20  i32 2, label %sw.bb2
21  i32 3, label %sw.bb3
22  ]
23
24sw.bb0:                                           ; preds = %entry
25  br label %return
26
27sw.bb1:                                           ; preds = %entry
28  br label %return
29
30sw.bb2:                                           ; preds = %entry
31  br label %return
32
33sw.bb3:                                           ; preds = %entry
34  br label %return
35
36sw.bb4:                                           ; preds = %entry
37  br label %return
38
39return:                                           ; preds = %entry, %sw.bb4, %sw.bb3, %sw.bb2, %sw.bb1
40  %retval.0 = phi i32 [ 4, %sw.bb4 ], [ 3, %sw.bb3 ], [ 2, %sw.bb2 ], [ 1, %sw.bb1 ], [ 0, %sw.bb0 ]
41  ret i32 %retval.0
42}
43
44; If 1 incoming phi value is a case constant of a switch, convert it to the switch condition:
45; https://bugs.llvm.org/show_bug.cgi?id=34471
46; This then subsequently should allow squashing of the other trivial case blocks.
47
48define i32 @PR34471(i32 %x) {
49; CHECK-LABEL: @PR34471(
50; CHECK-NEXT:  entry:
51; CHECK-NEXT:    switch i32 [[X:%.*]], label [[ELSE3:%.*]] [
52; CHECK-NEXT:    i32 17, label [[RETURN:%.*]]
53; CHECK-NEXT:    i32 19, label [[RETURN]]
54; CHECK-NEXT:    i32 42, label [[RETURN]]
55; CHECK-NEXT:    ]
56; CHECK:       else3:
57; CHECK-NEXT:    br label [[RETURN]]
58; CHECK:       return:
59; CHECK-NEXT:    [[R:%.*]] = phi i32 [ 0, [[ELSE3]] ], [ [[X]], [[ENTRY:%.*]] ], [ [[X]], [[ENTRY]] ], [ [[X]], [[ENTRY]] ]
60; CHECK-NEXT:    ret i32 [[R]]
61;
62entry:
63  switch i32 %x, label %else3 [
64  i32 17, label %return
65  i32 19, label %if19
66  i32 42, label %if42
67  ]
68
69if19:
70  br label %return
71
72if42:
73  br label %return
74
75else3:
76  br label %return
77
78return:
79  %r = phi i32 [ %x, %if19 ], [ %x, %if42 ], [ 0, %else3 ], [ 17, %entry ]
80  ret i32 %r
81}
82
83