xref: /dflybsd-src/lib/libc/x86_64/string/bcmp.S (revision b227f3f50d5dc0f5fdecd8f9df23e96e8521baaf)
1/*-
2 * Copyright (c) 1993 The Regents of the University of California.
3 * Copyright (c) 2003 Peter Wemm.
4 * Copyright (c) 2008 The DragonFly Project.
5 * All rights reserved.
6 *
7 * Redistribution and use in source and binary forms, with or without
8 * modification, are permitted provided that the following conditions
9 * are met:
10 * 1. Redistributions of source code must retain the above copyright
11 *    notice, this list of conditions and the following disclaimer.
12 * 2. Redistributions in binary form must reproduce the above copyright
13 *    notice, this list of conditions and the following disclaimer in the
14 *    documentation and/or other materials provided with the distribution.
15 * 3. Neither the name of the University nor the names of its contributors
16 *    may be used to endorse or promote products derived from this software
17 *    without specific prior written permission.
18 *
19 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
20 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
21 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
22 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
23 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
24 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
25 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
26 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
27 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
28 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
29 * SUCH DAMAGE.
30 */
31#include <machine/asm.h>
32
33ENTRY(bcmp)
34	movq    %rdx,%rcx
35	shrq    $3,%rcx
36	cld                                     /* compare forwards */
37	repe
38	cmpsq
39	jne     1f
40
41	movq    %rdx,%rcx
42	andq    $7,%rcx
43	je      1f
44	repe
45	cmpsb
461:
47	setne   %al
48	movsbl  %al,%eax
49	ret
50END(bcmp)
51
52	.section .note.GNU-stack,"",%progbits
53