1; Test that the strlen library call simplifier works correctly.
2;
3; RUN: opt < %s -instcombine -S | FileCheck %s
4
5target 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-f80:128:128"
6
7@hello = constant [6 x i8] c"hello\00"
8@null = constant [1 x i8] zeroinitializer
9@null_hello = constant [7 x i8] c"\00hello\00"
10@nullstring = constant i8 0
11@a = common global [32 x i8] zeroinitializer, align 1
12
13declare i32 @strlen(i8*)
14
15; Check strlen(string constant) -> integer constant.
16
17define i32 @test_simplify1() {
18; CHECK-LABEL: @test_simplify1(
19  %hello_p = getelementptr [6 x i8]* @hello, i32 0, i32 0
20  %hello_l = call i32 @strlen(i8* %hello_p)
21  ret i32 %hello_l
22; CHECK-NEXT: ret i32 5
23}
24
25define i32 @test_simplify2() {
26; CHECK-LABEL: @test_simplify2(
27  %null_p = getelementptr [1 x i8]* @null, i32 0, i32 0
28  %null_l = call i32 @strlen(i8* %null_p)
29  ret i32 %null_l
30; CHECK-NEXT: ret i32 0
31}
32
33define i32 @test_simplify3() {
34; CHECK-LABEL: @test_simplify3(
35  %null_hello_p = getelementptr [7 x i8]* @null_hello, i32 0, i32 0
36  %null_hello_l = call i32 @strlen(i8* %null_hello_p)
37  ret i32 %null_hello_l
38; CHECK-NEXT: ret i32 0
39}
40
41define i32 @test_simplify4() {
42; CHECK-LABEL: @test_simplify4(
43  %len = tail call i32 @strlen(i8* @nullstring) nounwind
44  ret i32 %len
45; CHECK-NEXT: ret i32 0
46}
47
48; Check strlen(x) == 0 --> *x == 0.
49
50define i1 @test_simplify5() {
51; CHECK-LABEL: @test_simplify5(
52  %hello_p = getelementptr [6 x i8]* @hello, i32 0, i32 0
53  %hello_l = call i32 @strlen(i8* %hello_p)
54  %eq_hello = icmp eq i32 %hello_l, 0
55  ret i1 %eq_hello
56; CHECK-NEXT: ret i1 false
57}
58
59define i1 @test_simplify6() {
60; CHECK-LABEL: @test_simplify6(
61  %null_p = getelementptr [1 x i8]* @null, i32 0, i32 0
62  %null_l = call i32 @strlen(i8* %null_p)
63  %eq_null = icmp eq i32 %null_l, 0
64  ret i1 %eq_null
65; CHECK-NEXT: ret i1 true
66}
67
68; Check strlen(x) != 0 --> *x != 0.
69
70define i1 @test_simplify7() {
71; CHECK-LABEL: @test_simplify7(
72  %hello_p = getelementptr [6 x i8]* @hello, i32 0, i32 0
73  %hello_l = call i32 @strlen(i8* %hello_p)
74  %ne_hello = icmp ne i32 %hello_l, 0
75  ret i1 %ne_hello
76; CHECK-NEXT: ret i1 true
77}
78
79define i1 @test_simplify8() {
80; CHECK-LABEL: @test_simplify8(
81  %null_p = getelementptr [1 x i8]* @null, i32 0, i32 0
82  %null_l = call i32 @strlen(i8* %null_p)
83  %ne_null = icmp ne i32 %null_l, 0
84  ret i1 %ne_null
85; CHECK-NEXT: ret i1 false
86}
87
88; Check cases that shouldn't be simplified.
89
90define i32 @test_no_simplify1() {
91; CHECK-LABEL: @test_no_simplify1(
92  %a_p = getelementptr [32 x i8]* @a, i32 0, i32 0
93  %a_l = call i32 @strlen(i8* %a_p)
94; CHECK-NEXT: %a_l = call i32 @strlen
95  ret i32 %a_l
96; CHECK-NEXT: ret i32 %a_l
97}
98