1/* Optimized version of the standard strncmp() function.
2   This file is part of the GNU C Library.
3   Copyright (C) 2000, 2001, 2003 Free Software Foundation, Inc.
4   Contributed by Dan Pop <Dan.Pop@cern.ch>.
5
6   The GNU C Library is free software; you can redistribute it and/or
7   modify it under the terms of the GNU Lesser General Public
8   License as published by the Free Software Foundation; either
9   version 2.1 of the License, or (at your option) any later version.
10
11   The GNU C Library is distributed in the hope that it will be useful,
12   but WITHOUT ANY WARRANTY; without even the implied warranty of
13   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
14   Lesser General Public License for more details.
15
16   You should have received a copy of the GNU Lesser General Public
17   License along with the GNU C Library; if not, see
18   <http://www.gnu.org/licenses/>.  */
19
20/* Return: the result of the comparison
21
22   Inputs:
23        in0:    s1
24        in1:    s2
25	in2:	n
26
27   Unlike memcmp(), this function is optimized for mismatches within the
28   first few characters.  */
29
30#include <sysdep.h>
31#undef ret
32
33#define s1		in0
34#define s2		in1
35#define n		in2
36
37#define val1		r15
38#define val2		r16
39
40
41ENTRY(strncmp)
42	alloc	r2 = ar.pfs, 3, 0, 0, 0
43	mov	ret0 = r0
44	cmp.eq  p6, p0 = r0, r0		/* set p6 */
45	cmp.eq	p7, p0 = n, r0		/* return immediately if n == 0 */
46(p7)	br.cond.spnt .restore_and_exit ;;
47.loop:
48	ld1	val1 = [s1], 1
49	ld1	val2 = [s2], 1
50	adds	n = -1, n		/* n-- */
51	;;
52	cmp.ne.and p6, p0 = val1, r0
53	cmp.ne.and p6, p0 = val2, r0
54	cmp.ne.and p6, p0 = n, r0
55	cmp.eq.and p6, p0 = val1, val2
56(p6)	br.cond.sptk .loop
57	sub	ret0 = val1, val2
58.restore_and_exit:
59	br.ret.sptk.many b0
60END(strncmp)
61libc_hidden_weak (strncmp)
62