rockbox/firmware/asm/memset16.c

80 lines
2.3 KiB
C

/***************************************************************************
* __________ __ ___.
* Open \______ \ ____ ____ | | _\_ |__ _______ ___
* Source | _// _ \_/ ___\| |/ /| __ \ / _ \ \/ /
* Jukebox | | ( <_> ) \___| < | \_\ ( <_> > < <
* Firmware |____|_ /\____/ \___ >__|_ \|___ /\____/__/\_ \
* \/ \/ \/ \/ \/
* $Id$
*
* Copyright (C) 2006 by Jens Arnold
*
* 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 (at your option) any later version.
*
* This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
* KIND, either express or implied.
*
****************************************************************************/
#include "string-extra.h" /* memset16() */
#include <stdint.h>
#define LBLOCKSIZE (sizeof(long)/2)
#define ROCKBOX_UNALIGNED(X) ((uintptr_t)X & (sizeof(long) - 1))
#define TOO_SMALL(LEN) ((LEN) < LBLOCKSIZE)
void memset16(void *dst, int val, size_t len)
{
#if defined(PREFER_SIZE_OVER_SPEED) || defined(__OPTIMIZE_SIZE__)
unsigned short *p = (unsigned short *)dst;
while (len--)
*p++ = val;
#else
unsigned short *p = (unsigned short *)dst;
unsigned int i;
unsigned long buffer;
unsigned long *aligned_addr;
if (!TOO_SMALL(len) && !ROCKBOX_UNALIGNED(dst))
{
aligned_addr = (unsigned long *)dst;
val &= 0xffff;
if (LBLOCKSIZE == 2)
{
buffer = (val << 16) | val;
}
else
{
buffer = 0;
for (i = 0; i < LBLOCKSIZE; i++)
buffer = (buffer << 16) | val;
}
while (len >= LBLOCKSIZE*4)
{
*aligned_addr++ = buffer;
*aligned_addr++ = buffer;
*aligned_addr++ = buffer;
*aligned_addr++ = buffer;
len -= 4*LBLOCKSIZE;
}
while (len >= LBLOCKSIZE)
{
*aligned_addr++ = buffer;
len -= LBLOCKSIZE;
}
p = (unsigned short *)aligned_addr;
}
while (len--)
*p++ = val;
#endif /* not PREFER_SIZE_OVER_SPEED */
}