1/* Optimized version of the standard strcmp() function.
2 This file is part of the GNU C Library.
3 Copyright (C) 2000-2022 Free Software Foundation, Inc.
4
5 The GNU C Library is free software; you can redistribute it and/or
6 modify it under the terms of the GNU Lesser General Public
7 License as published by the Free Software Foundation; either
8 version 2.1 of the License, or (at your option) any later version.
9
10 The GNU C Library is distributed in the hope that it will be useful,
11 but WITHOUT ANY WARRANTY; without even the implied warranty of
12 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
13 Lesser General Public License for more details.
14
15 You should have received a copy of the GNU Lesser General Public
16 License along with the GNU C Library; if not, see
17 <https://www.gnu.org/licenses/>. */
18
19/* Return: the result of the comparison
20
21 Inputs:
22 in0: s1
23 in1: s2
24
25 Unlike memcmp(), this function is optimized for mismatches within the
26 first few characters. */
27
28#include <sysdep.h>
29#undef ret
30
31#define s1 in0
32#define s2 in1
33
34#define val1 r15
35#define val2 r16
36
37
38ENTRY(strcmp)
39 alloc r2 = ar.pfs, 2, 0, 0, 0
40.loop:
41 ld1 val1 = [s1], 1
42 ld1 val2 = [s2], 1
43 cmp.eq p6, p0 = r0, r0 // set p6
44 ;;
45 cmp.ne.and p6, p0 = val1, r0
46 cmp.ne.and p6, p0 = val2, r0
47 cmp.eq.and p6, p0 = val1, val2
48(p6) br.cond.sptk .loop
49 sub ret0 = val1, val2
50 br.ret.sptk.many b0
51END(strcmp)
52libc_hidden_builtin_def (strcmp)
53

source code of glibc/sysdeps/ia64/strcmp.S