freebsd-nq/lib/libc/i386/string/index.S
1997-02-22 15:12:41 +00:00

70 lines
2.4 KiB
ArmAsm

/*
* Copyright (c) 1993 Winning Strategies, Inc.
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. All advertising materials mentioning features or use of this software
* must display the following acknowledgement:
* This product includes software developed by Winning Strategies, Inc.
* 4. The name of the author may not be used to endorse or promote products
* derived from this software withough specific prior written permission
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
* IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
* NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
* THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*
* $Id$
*/
#if defined(LIBC_RCS) && !defined(lint)
.text
.asciz "$Id$"
#endif /* LIBC_RCS and not lint */
#include "DEFS.h"
/*
* index(s, c)
* return a pointer to the first occurance of the character c in
* string s, or NULL if c does not occur in the string.
*
* %edx - pointer iterating through string
* %eax - pointer to first occurance of 'c'
* %cl - character we're comparing against
* %bl - character at %edx
*
* Written by:
* J.T. Conklin (jtc@wimsey.com), Winning Strategies, Inc.
*/
ENTRY(index)
pushl %ebx
movl 8(%esp),%eax
movb 12(%esp),%cl
.align 2,0x90
L1:
movb (%eax),%bl
cmpb %bl,%cl /* found char??? */
je L2
incl %eax
testb %bl,%bl /* null terminator??? */
jne L1
xorl %eax,%eax
L2:
popl %ebx
ret