xref: /llvm-project/llvm/test/Transforms/InstCombine/strchr-4.ll (revision 4ab40eca080965c65802710e39adbb78c4ce7bde)
1d8b22243SMartin Sebor; NOTE: Assertions have been autogenerated by utils/update_test_checks.py
2d8b22243SMartin Sebor; RUN: opt < %s -passes=instcombine -S | FileCheck %s
3d8b22243SMartin Sebor;
4d8b22243SMartin Sebor; Verify that the result of strchr calls used in equality expressions
5d8b22243SMartin Sebor; with either the first argument or null are optimally folded.
6d8b22243SMartin Sebor
7*4ab40ecaSBjorn Petterssondeclare ptr @strchr(ptr, i32)
8d8b22243SMartin Sebor
9d8b22243SMartin Sebor
10d8b22243SMartin Sebor; Fold strchr(s, c) == s to *s == c.
11d8b22243SMartin Sebor
12*4ab40ecaSBjorn Petterssondefine i1 @fold_strchr_s_c_eq_s(ptr %s, i32 %c) {
13d8b22243SMartin Sebor; CHECK-LABEL: @fold_strchr_s_c_eq_s(
14*4ab40ecaSBjorn Pettersson; CHECK-NEXT:    [[TMP1:%.*]] = load i8, ptr [[S:%.*]], align 1
15516915beSMartin Sebor; CHECK-NEXT:    [[TMP2:%.*]] = trunc i32 [[C:%.*]] to i8
16516915beSMartin Sebor; CHECK-NEXT:    [[CHAR0CMP:%.*]] = icmp eq i8 [[TMP1]], [[TMP2]]
17516915beSMartin Sebor; CHECK-NEXT:    ret i1 [[CHAR0CMP]]
18d8b22243SMartin Sebor;
19*4ab40ecaSBjorn Pettersson  %p = call ptr @strchr(ptr %s, i32 %c)
20*4ab40ecaSBjorn Pettersson  %cmp = icmp eq ptr %p, %s
21d8b22243SMartin Sebor  ret i1 %cmp
22d8b22243SMartin Sebor}
23d8b22243SMartin Sebor
24d8b22243SMartin Sebor
25d8b22243SMartin Sebor; Fold strchr(s, c) != s to *s != c.
26d8b22243SMartin Sebor
27*4ab40ecaSBjorn Petterssondefine i1 @fold_strchr_s_c_neq_s(ptr %s, i32 %c) {
28d8b22243SMartin Sebor; CHECK-LABEL: @fold_strchr_s_c_neq_s(
29*4ab40ecaSBjorn Pettersson; CHECK-NEXT:    [[TMP1:%.*]] = load i8, ptr [[S:%.*]], align 1
30516915beSMartin Sebor; CHECK-NEXT:    [[TMP2:%.*]] = trunc i32 [[C:%.*]] to i8
31516915beSMartin Sebor; CHECK-NEXT:    [[CHAR0CMP:%.*]] = icmp ne i8 [[TMP1]], [[TMP2]]
32516915beSMartin Sebor; CHECK-NEXT:    ret i1 [[CHAR0CMP]]
33d8b22243SMartin Sebor;
34*4ab40ecaSBjorn Pettersson  %p = call ptr @strchr(ptr %s, i32 %c)
35*4ab40ecaSBjorn Pettersson  %cmp = icmp ne ptr %p, %s
36d8b22243SMartin Sebor  ret i1 %cmp
37d8b22243SMartin Sebor}
38d8b22243SMartin Sebor
39d8b22243SMartin Sebor
40d8b22243SMartin Sebor; Fold strchr(s, '\0') == null to false.  (A string must be nul-terminated,
41d8b22243SMartin Sebor; otherwise the call would read past the end of the array.)
42d8b22243SMartin Sebor
43*4ab40ecaSBjorn Petterssondefine i1 @fold_strchr_s_nul_eqz(ptr %s) {
44d8b22243SMartin Sebor; CHECK-LABEL: @fold_strchr_s_nul_eqz(
45516915beSMartin Sebor; CHECK-NEXT:    ret i1 false
46d8b22243SMartin Sebor;
47*4ab40ecaSBjorn Pettersson  %p = call ptr @strchr(ptr %s, i32 0)
48*4ab40ecaSBjorn Pettersson  %cmp = icmp eq ptr %p, null
49d8b22243SMartin Sebor  ret i1 %cmp
50d8b22243SMartin Sebor}
51d8b22243SMartin Sebor
52d8b22243SMartin Sebor
53d8b22243SMartin Sebor; Fold strchr(s, '\0') != null to true.
54d8b22243SMartin Sebor
55*4ab40ecaSBjorn Petterssondefine i1 @fold_strchr_s_nul_nez(ptr %s) {
56d8b22243SMartin Sebor; CHECK-LABEL: @fold_strchr_s_nul_nez(
57516915beSMartin Sebor; CHECK-NEXT:    ret i1 true
58d8b22243SMartin Sebor;
59*4ab40ecaSBjorn Pettersson  %p = call ptr @strchr(ptr %s, i32 0)
60*4ab40ecaSBjorn Pettersson  %cmp = icmp ne ptr %p, null
61d8b22243SMartin Sebor  ret i1 %cmp
62d8b22243SMartin Sebor}
63d8b22243SMartin Sebor
64d8b22243SMartin Sebor
65d8b22243SMartin Sebor@a5 = constant [5 x i8] c"12345";
66d8b22243SMartin Sebor
67d8b22243SMartin Sebor; Fold strchr(a5, c) == a5 to *a5 == c.
68d8b22243SMartin Sebor
69d8b22243SMartin Sebordefine i1 @fold_strchr_a_c_eq_a(i32 %c) {
70d8b22243SMartin Sebor; CHECK-LABEL: @fold_strchr_a_c_eq_a(
71516915beSMartin Sebor; CHECK-NEXT:    [[TMP1:%.*]] = trunc i32 [[C:%.*]] to i8
72516915beSMartin Sebor; CHECK-NEXT:    [[CHAR0CMP:%.*]] = icmp eq i8 [[TMP1]], 49
73516915beSMartin Sebor; CHECK-NEXT:    ret i1 [[CHAR0CMP]]
74d8b22243SMartin Sebor;
75*4ab40ecaSBjorn Pettersson  %q = call ptr @strchr(ptr @a5, i32 %c)
76*4ab40ecaSBjorn Pettersson  %cmp = icmp eq ptr %q, @a5
77d8b22243SMartin Sebor  ret i1 %cmp
78d8b22243SMartin Sebor}
79