d/freebsd-skq
1
0
Fork 0
Code Issues Pull Requests Packages Projects Releases Wiki Activity

remove obsolete i386 MD memchr implementation

Browse Source 
bde reports (in a reply to r351700 commit mail):
    This uses scasb, which was last optimal on the 8086, or perhaps the
    original i386.  On freefall, it is several times slower than the
    naive translation of the naive C code.

Reported by:	bde
Reviewed by:	kib, markj
Sponsored by:	The FreeBSD Foundation
Differential Revision:	https://reviews.freebsd.org/D21785
This commit is contained in:
emaste 2019-09-25 16:49:22 +00:00
parent fbe7e9c7e4
commit 79a5bb91d6
2 changed files with 0 additions and 62 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

1
lib/libc/i386/string/Makefile.inc
View File

@ -5,7 +5,6 @@ MDSRCS+= \
bcopy.S \
bzero.S \
ffs.S \
memchr.S \
memcmp.S \
memcpy.S \
memmove.S \

61
lib/libc/i386/string/memchr.S
View File

@ -1,61 +0,0 @@
/*
* 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 without 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.
*/
#include <machine/asm.h>
__FBSDID("$FreeBSD$");
/*
* memchr (b, c, len)
* locates the first occurrence of c in string b.
*
* Written by:
* J.T. Conklin (jtc@wimsey.com), Winning Strategies, Inc.
*/
ENTRY(memchr)
pushl %edi
movl 8(%esp),%edi /* string address */
movl 12(%esp),%eax /* set character to search for */
movl 16(%esp),%ecx /* set length of search */
testl %esp,%esp /* clear Z flag, for len == 0 */
cld /* set search forward */
repne /* search! */
scasb
jnz L1 /* scan failed, return null */
leal -1(%edi),%eax /* adjust result of scan */
popl %edi
ret
.align 2,0x90
L1: xorl %eax,%eax
popl %edi
ret
END(memchr)
.section .note.GNU-stack,"",%progbits