xref: /openbsd/sys/lib/libkern/arch/amd64/scanc.S (revision 73471bf0)
1/*	$NetBSD: scanc.S,v 1.1 2001/06/19 00:22:47 fvdl Exp $	*/
2
3/*-
4 * Copyright (c) 1998 The NetBSD Foundation, Inc.
5 * All rights reserved.
6 *
7 * This code is derived from software contributed to The NetBSD Foundation
8 * by Charles M. Hannum.
9 *
10 * Redistribution and use in source and binary forms, with or without
11 * modification, are permitted provided that the following conditions
12 * are met:
13 * 1. Redistributions of source code must retain the above copyright
14 *    notice, this list of conditions and the following disclaimer.
15 * 2. Redistributions in binary form must reproduce the above copyright
16 *    notice, this list of conditions and the following disclaimer in the
17 *    documentation and/or other materials provided with the distribution.
18 *
19 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
20 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
21 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
22 * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
23 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
24 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
25 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
26 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
27 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
28 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
29 * POSSIBILITY OF SUCH DAMAGE.
30 */
31
32/*
33 * Adapted for NetBSD/x86_64 by Frank van der Linden <fvdl@wasabisystems.com>
34 */
35
36#include <machine/asm.h>
37
38ENTRY(scanc)
39	RETGUARD_SETUP(scanc, r10)
40	movq	%rdx,%r11
41	movb	%cl,%dl
42	movl	%edi,%ecx
43	testl	%ecx,%ecx
44	jz	2f
45	movq	%r11,%rdi
46	xorq	%rax,%rax
471:
48	lodsb
49	testb	%dl,(%rax,%rdi)
50	jnz	2f
51	decl	%ecx
52	jnz	1b
532:
54	movl	%ecx,%eax
55	RETGUARD_CHECK(scanc, r10)
56	ret
57