diff options
author | wollman <wollman@FreeBSD.org> | 1994-08-05 01:19:12 +0000 |
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committer | wollman <wollman@FreeBSD.org> | 1994-08-05 01:19:12 +0000 |
commit | e017c781cac0ce8879390a958837f07f3ae09f36 (patch) | |
tree | 3e3913f9a690f2310dfc0d620e8803f623b40b54 /lib/libc/i386/string/ffs.S | |
parent | 962b8cc8e0b8959ba3824a40a58f846de4027f04 (diff) | |
download | FreeBSD-src-e017c781cac0ce8879390a958837f07f3ae09f36.zip FreeBSD-src-e017c781cac0ce8879390a958837f07f3ae09f36.tar.gz |
First crack at making libc work with the new make macros. It compiles on
my machine, and a simple static (genassym) and shared (sysctl) executable
both work. Still to be done: RPCand YP merge.
Diffstat (limited to 'lib/libc/i386/string/ffs.S')
-rw-r--r-- | lib/libc/i386/string/ffs.S | 58 |
1 files changed, 58 insertions, 0 deletions
diff --git a/lib/libc/i386/string/ffs.S b/lib/libc/i386/string/ffs.S new file mode 100644 index 0000000..42b6357 --- /dev/null +++ b/lib/libc/i386/string/ffs.S @@ -0,0 +1,58 @@ +/* + * 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: ffs.S,v 1.1 1993/12/05 13:01:43 ats Exp $ + */ + +#if defined(LIBC_RCS) && !defined(lint) + .asciz "$Id: ffs.S,v 1.1 1993/12/05 13:01:43 ats Exp $" +#endif /* LIBC_RCS and not lint */ + +#include "DEFS.h" + +/* + * ffs(value) + * finds the first bit set in value and returns the index of + * that bit. Bits are numbered starting from 1, starting at the + * rightmost bit. A return value of 0 means that the argument + * was zero. + * + * Written by: + * J.T. Conklin (jtc@wimsey.com), Winning Strategies, Inc. + */ + +ENTRY(ffs) + bsfl 4(%esp),%eax + jz L1 /* ZF is set if all bits are 0 */ + incl %eax /* bits numbered from 1, not 0 */ + ret + + .align 2 +L1: xorl %eax,%eax /* clear result */ + ret |