1; NOTE: Assertions have been autogenerated by utils/update_test_checks.py
2; Verify that calls to memcmp with counts in excess of the array sizes are
3; either folded gracefully or expanded to library calls.
4;
5; RUN: opt < %s -passes=instcombine -S -data-layout="E" | FileCheck %s --check-prefixes=BE
6; RUN: opt < %s -passes=instcombine -S -data-layout="e" | FileCheck %s --check-prefixes=LE
7
8declare i32 @memcmp(i8*, i8*, i64)
9
10@ia16a = constant [4 x i16] [i16 24930, i16 25444, i16 25958, i16 26472]
11@ia16b = constant [5 x i16] [i16 24930, i16 25444, i16 25958, i16 26472, i16 26992]
12@ia16c = constant [6 x i16] [i16 24930, i16 25444, i16 25958, i16 26472, i16 26993, i16 29042]
13
14
15; Fold calls with a count in excess of the size of one of the arrays that
16; differ.  They're strictly undefined but folding the result to the expected
17; value (analogous to strncmp) is safer than letting a SIMD library
18; implementation return a bogus value.
19
20define void @fold_memcmp_mismatch_too_big(i32* %pcmp) {
21; BE-LABEL: @fold_memcmp_mismatch_too_big(
22; BE-NEXT:    store i32 -1, i32* [[PCMP:%.*]], align 4
23; BE-NEXT:    [[PSTOR_CB:%.*]] = getelementptr i32, i32* [[PCMP]], i64 1
24; BE-NEXT:    store i32 1, i32* [[PSTOR_CB]], align 4
25; BE-NEXT:    ret void
26;
27; LE-LABEL: @fold_memcmp_mismatch_too_big(
28; LE-NEXT:    store i32 -1, i32* [[PCMP:%.*]], align 4
29; LE-NEXT:    [[PSTOR_CB:%.*]] = getelementptr i32, i32* [[PCMP]], i64 1
30; LE-NEXT:    store i32 1, i32* [[PSTOR_CB]], align 4
31; LE-NEXT:    ret void
32;
33  %p0 = getelementptr [5 x i16], [5 x i16]* @ia16b, i64 0, i64 0
34  %p1 = bitcast i16* %p0 to i8*
35  %q0 = getelementptr [6 x i16], [6 x i16]* @ia16c, i64 0, i64 0
36  %q1 = bitcast i16* %q0 to i8*
37
38  %cmp_bc = call i32 @memcmp(i8* %p1, i8* %q1, i64 12)
39  %pstor_bc = getelementptr i32, i32* %pcmp, i64 0
40  store i32 %cmp_bc, i32* %pstor_bc
41
42  %cmp_cb = call i32 @memcmp(i8* %q1, i8* %p1, i64 12)
43  %pstor_cb = getelementptr i32, i32* %pcmp, i64 1
44  store i32 %cmp_cb, i32* %pstor_cb
45
46  ret void
47}
48
49
50; Fold even calls with excessive byte counts of arrays with matching bytes.
51; Like in the instances above, this is preferable to letting the undefined
52; calls take place, although it does prevent sanitizers from detecting them.
53
54define void @fold_memcmp_match_too_big(i32* %pcmp) {
55; BE-LABEL: @fold_memcmp_match_too_big(
56; BE-NEXT:    store i32 0, i32* [[PCMP:%.*]], align 4
57; BE-NEXT:    [[PSTOR_AB_M1:%.*]] = getelementptr i32, i32* [[PCMP]], i64 1
58; BE-NEXT:    store i32 0, i32* [[PSTOR_AB_M1]], align 4
59; BE-NEXT:    ret void
60;
61; LE-LABEL: @fold_memcmp_match_too_big(
62; LE-NEXT:    store i32 0, i32* [[PCMP:%.*]], align 4
63; LE-NEXT:    [[PSTOR_AB_M1:%.*]] = getelementptr i32, i32* [[PCMP]], i64 1
64; LE-NEXT:    store i32 0, i32* [[PSTOR_AB_M1]], align 4
65; LE-NEXT:    ret void
66;
67  %p0 = getelementptr [4 x i16], [4 x i16]* @ia16a, i64 0, i64 0
68  %p1 = bitcast i16* %p0 to i8*
69  %q0 = getelementptr [5 x i16], [5 x i16]* @ia16b, i64 0, i64 0
70  %q1 = bitcast i16* %q0 to i8*
71
72  %cmp_ab_9 = call i32 @memcmp(i8* %p1, i8* %q1, i64 9)
73  %pstor_ab_9 = getelementptr i32, i32* %pcmp, i64 0
74  store i32 %cmp_ab_9, i32* %pstor_ab_9
75
76  %cmp_ab_m1 = call i32 @memcmp(i8* %p1, i8* %q1, i64 -1)
77  %pstor_ab_m1 = getelementptr i32, i32* %pcmp, i64 1
78  store i32 %cmp_ab_m1, i32* %pstor_ab_m1
79
80  ret void
81}
82