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1; Test that the strstr library call simplifier works correctly.
2;
3; RUN: opt < %s -instcombine -S | FileCheck %s
4
5target datalayout = "e-p:64:64:64-i1:8:8-i8:8:8-i16:16:16-i32:32:32-i64:64:64-f32:32:32-f64:64:64-v64:64:64-v128:128:128-a0:0:64-s0:64:64-f80:128:128-n8:16:32:64-S128"
6
7@.str = private constant [1 x i8] zeroinitializer
8@.str1 = private constant [2 x i8] c"a\00"
9@.str2 = private constant [6 x i8] c"abcde\00"
10@.str3 = private constant [4 x i8] c"bcd\00"
11
12declare i8* @strstr(i8*, i8*)
13
14; Check strstr(str, "") -> str.
15
16define i8* @test_simplify1(i8* %str) {
17; CHECK-LABEL: @test_simplify1(
18  %pat = getelementptr inbounds [1 x i8], [1 x i8]* @.str, i32 0, i32 0
19  %ret = call i8* @strstr(i8* %str, i8* %pat)
20  ret i8* %ret
21; CHECK-NEXT: ret i8* %str
22}
23
24; Check strstr(str, "a") -> strchr(str, 'a').
25
26define i8* @test_simplify2(i8* %str) {
27; CHECK-LABEL: @test_simplify2(
28  %pat = getelementptr inbounds [2 x i8], [2 x i8]* @.str1, i32 0, i32 0
29  %ret = call i8* @strstr(i8* %str, i8* %pat)
30  ret i8* %ret
31; CHECK-NEXT: @strchr(i8* %str, i32 97)
32}
33
34; Check strstr("abcde", "bcd") -> "abcde" + 1.
35
36define i8* @test_simplify3() {
37; CHECK-LABEL: @test_simplify3(
38  %str = getelementptr inbounds [6 x i8], [6 x i8]* @.str2, i32 0, i32 0
39  %pat = getelementptr inbounds [4 x i8], [4 x i8]* @.str3, i32 0, i32 0
40  %ret = call i8* @strstr(i8* %str, i8* %pat)
41  ret i8* %ret
42; CHECK-NEXT: getelementptr inbounds ([6 x i8], [6 x i8]* @.str2, i64 0, i64 1)
43}
44
45; Check strstr(str, str) -> str.
46
47define i8* @test_simplify4(i8* %str) {
48; CHECK-LABEL: @test_simplify4(
49  %ret = call i8* @strstr(i8* %str, i8* %str)
50  ret i8* %ret
51; CHECK-NEXT: ret i8* %str
52}
53
54; Check strstr(str, pat) == str -> strncmp(str, pat, strlen(str)) == 0.
55
56define i1 @test_simplify5(i8* %str, i8* %pat) {
57; CHECK-LABEL: @test_simplify5(
58  %ret = call i8* @strstr(i8* %str, i8* %pat)
59  %cmp = icmp eq i8* %ret, %str
60  ret i1 %cmp
61; CHECK: [[LEN:%[a-z]+]] = call {{i[0-9]+}} @strlen(i8* %pat)
62; CHECK: [[NCMP:%[a-z]+]] = call {{i[0-9]+}} @strncmp(i8* %str, i8* %pat, {{i[0-9]+}} [[LEN]])
63; CHECK: icmp eq {{i[0-9]+}} [[NCMP]], 0
64; CHECK: ret i1
65}
66