xref: /llvm-project/llvm/test/Transforms/SimplifyCFG/switch-masked-bits.ll (revision 07b9d231ff9baa6473b0dd588a3ce5330d3e4871)
1; NOTE: Assertions have been autogenerated by utils/update_test_checks.py
2; RUN: opt -S -passes=simplifycfg -simplifycfg-require-and-preserve-domtree=1 < %s | FileCheck %s
3
4define i32 @test1(i32 %x) nounwind {
5; CHECK-LABEL: @test1(
6; CHECK-NEXT:  common.ret:
7; CHECK-NEXT:    [[I:%.*]] = shl i32 [[X:%.*]], 1
8; CHECK-NEXT:    [[COND:%.*]] = icmp eq i32 [[I]], 24
9; CHECK-NEXT:    [[DOT:%.*]] = select i1 [[COND]], i32 5, i32 0
10; CHECK-NEXT:    ret i32 [[DOT]]
11;
12  %i = shl i32 %x, 1
13  switch i32 %i, label %a [
14  i32 21, label %b
15  i32 24, label %c
16  ]
17
18a:
19  ret i32 0
20b:
21  ret i32 3
22c:
23  ret i32 5
24}
25
26
27define i32 @test2(i32 %x) nounwind {
28; CHECK-LABEL: @test2(
29; CHECK-NEXT:  a:
30; CHECK-NEXT:    ret i32 0
31;
32  %i = shl i32 %x, 1
33  switch i32 %i, label %a [
34  i32 21, label %b
35  i32 23, label %c
36  ]
37
38a:
39  ret i32 0
40b:
41  ret i32 3
42c:
43  ret i32 5
44}
45
46; We're sign extending an 8-bit value.
47; The switch condition must be in the range [-128, 127], so any cases outside of that range must be dead.
48
49define i1 @repeated_signbits(i8 %condition) {
50; CHECK-LABEL: @repeated_signbits(
51; CHECK-NEXT:  entry:
52; CHECK-NEXT:    [[SEXT:%.*]] = sext i8 [[CONDITION:%.*]] to i32
53; CHECK-NEXT:    switch i32 [[SEXT]], label [[DEFAULT:%.*]] [
54; CHECK-NEXT:      i32 0, label [[COMMON_RET:%.*]]
55; CHECK-NEXT:      i32 127, label [[COMMON_RET]]
56; CHECK-NEXT:      i32 -128, label [[COMMON_RET]]
57; CHECK-NEXT:      i32 -1, label [[COMMON_RET]]
58; CHECK-NEXT:    ]
59; CHECK:       common.ret:
60; CHECK-NEXT:    [[COMMON_RET_OP:%.*]] = phi i1 [ false, [[DEFAULT]] ], [ true, [[ENTRY:%.*]] ], [ true, [[ENTRY]] ], [ true, [[ENTRY]] ], [ true, [[ENTRY]] ]
61; CHECK-NEXT:    ret i1 [[COMMON_RET_OP]]
62; CHECK:       default:
63; CHECK-NEXT:    br label [[COMMON_RET]]
64;
65entry:
66  %sext = sext i8 %condition to i32
67  switch i32 %sext, label %default [
68  i32 -2147483648, label %a
69  i32 -129, label %a
70  i32 -128, label %a
71  i32 -1, label %a
72  i32  0, label %a
73  i32  127, label %a
74  i32  128, label %a
75  i32  2147483647, label %a
76  ]
77
78a:
79  ret i1 1
80
81default:
82  ret i1 0
83}
84
85