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Diffstat (limited to 'lib/libc/i386/string/index.S')
| -rw-r--r-- | lib/libc/i386/string/index.S | 67 |
1 files changed, 67 insertions, 0 deletions
diff --git a/lib/libc/i386/string/index.S b/lib/libc/i386/string/index.S new file mode 100644 index 000000000000..c36e55a0a8e4 --- /dev/null +++ b/lib/libc/i386/string/index.S @@ -0,0 +1,67 @@ +/* + * 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. + */ + +#if defined(LIBC_RCS) && !defined(lint) + .text + .asciz "$FreeBSD$" +#endif /* LIBC_RCS and not lint */ + +#include <machine/asm.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 |