1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
|
; NOTE: Assertions have been autogenerated by utils/update_test_checks.py
; RUN: opt < %s -passes=instcombine -S | FileCheck %s
;
; Verify that the result of memrchr calls with past-the-end pointers used
; don't cause trouble and are optimally folded.
declare i32 @memcmp(i8*, i8*, i64)
@a5 = constant [5 x i8] c"12345";
; Fold memcmp(a5, a5 + 5, n) to 0 on the assumption that n is 0 otherwise
; the call would be undefined.
define i32 @fold_memcmp_a5_a5p5_n(i64 %n) {
; CHECK-LABEL: @fold_memcmp_a5_a5p5_n(
; CHECK-NEXT: ret i32 0
;
%pa5_p0 = getelementptr [5 x i8], [5 x i8]* @a5, i32 0, i32 0
%pa5_p5 = getelementptr [5 x i8], [5 x i8]* @a5, i32 0, i32 5
%cmp = call i32 @memcmp(i8* %pa5_p0, i8* %pa5_p5, i64 %n)
ret i32 %cmp
}
; Same as above but for memcmp(a5 + 5, a5 + 5, n).
define i32 @fold_memcmp_a5p5_a5p5_n(i64 %n) {
; CHECK-LABEL: @fold_memcmp_a5p5_a5p5_n(
; CHECK-NEXT: ret i32 0
;
%pa5_p5 = getelementptr [5 x i8], [5 x i8]* @a5, i32 0, i32 5
%qa5_p5 = getelementptr [5 x i8], [5 x i8]* @a5, i32 0, i32 5
%cmp = call i32 @memcmp(i8* %pa5_p5, i8* %qa5_p5, i64 %n)
ret i32 %cmp
}
; TODO: Likewise, fold memcmp(a5 + i, a5 + 5, n) to 0 on same basis.
define i32 @fold_memcmp_a5pi_a5p5_n(i32 %i, i64 %n) {
; CHECK-LABEL: @fold_memcmp_a5pi_a5p5_n(
; CHECK-NEXT: [[TMP1:%.*]] = sext i32 [[I:%.*]] to i64
; CHECK-NEXT: [[PA5_PI:%.*]] = getelementptr [5 x i8], [5 x i8]* @a5, i64 0, i64 [[TMP1]]
; CHECK-NEXT: [[CMP:%.*]] = call i32 @memcmp(i8* [[PA5_PI]], i8* getelementptr inbounds ([5 x i8], [5 x i8]* @a5, i64 1, i64 0), i64 [[N:%.*]])
; CHECK-NEXT: ret i32 [[CMP]]
;
%pa5_pi = getelementptr [5 x i8], [5 x i8]* @a5, i32 0, i32 %i
%pa5_p5 = getelementptr [5 x i8], [5 x i8]* @a5, i32 0, i32 5
%cmp = call i32 @memcmp(i8* %pa5_pi, i8* %pa5_p5, i64 %n)
ret i32 %cmp
}
|
