mirror of
https://github.com/xcat2/xNBA.git
synced 2024-12-15 15:51:44 +00:00
64 lines
1.8 KiB
C
64 lines
1.8 KiB
C
/*
|
|
* Copyright (C) 2007 Michael Brown <mbrown@fensystems.co.uk>.
|
|
*
|
|
* This program is free software; you can redistribute it and/or
|
|
* modify it under the terms of the GNU General Public License as
|
|
* published by the Free Software Foundation; either version 2 of the
|
|
* License, or any later version.
|
|
*
|
|
* This program is distributed in the hope that it will be useful, but
|
|
* WITHOUT ANY WARRANTY; without even the implied warranty of
|
|
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
|
|
* General Public License for more details.
|
|
*
|
|
* You should have received a copy of the GNU General Public License
|
|
* along with this program; if not, write to the Free Software
|
|
* Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
|
|
*/
|
|
|
|
/** @file
|
|
*
|
|
* Optimised string operations
|
|
*
|
|
*/
|
|
|
|
#include <string.h>
|
|
|
|
/**
|
|
* Copy memory area
|
|
*
|
|
* @v dest Destination address
|
|
* @v src Source address
|
|
* @v len Length
|
|
* @ret dest Destination address
|
|
*/
|
|
__attribute__ (( regparm ( 3 ) )) void * __memcpy ( void *dest,
|
|
const void *src,
|
|
size_t len ) {
|
|
void *edi = dest;
|
|
const void *esi = src;
|
|
int discard_ecx;
|
|
|
|
/* We often do large dword-aligned and dword-length block
|
|
* moves. Using movsl rather than movsb speeds these up by
|
|
* around 32%.
|
|
*/
|
|
if ( len >> 2 ) {
|
|
__asm__ __volatile__ ( "rep movsl"
|
|
: "=&D" ( edi ), "=&S" ( esi ),
|
|
"=&c" ( discard_ecx )
|
|
: "0" ( edi ), "1" ( esi ),
|
|
"2" ( len >> 2 )
|
|
: "memory" );
|
|
}
|
|
if ( len & 0x02 ) {
|
|
__asm__ __volatile__ ( "movsw" : "=&D" ( edi ), "=&S" ( esi )
|
|
: "0" ( edi ), "1" ( esi ) : "memory" );
|
|
}
|
|
if ( len & 0x01 ) {
|
|
__asm__ __volatile__ ( "movsb" : "=&D" ( edi ), "=&S" ( esi )
|
|
: "0" ( edi ), "1" ( esi ) : "memory" );
|
|
}
|
|
return dest;
|
|
}
|