firmware/common/memset16.c

   1 /***************************************************************************
   2  *             __________               __   ___.
   3  *   Open      \______   \ ____   ____ |  | _\_ |__   _______  ___
   4  *   Source     |       _//  _ \_/ ___\|  |/ /| __ \ /  _ \  \/  /
   5  *   Jukebox    |    |   (  <_> )  \___|    < | \_\ (  <_> > <  <
   6  *   Firmware   |____|_  /\____/ \___  >__|_ \|___  /\____/__/\_ \
   7  *                     \/            \/     \/    \/            \/
   8  * $Id$
   9  *
  10  * Copyright (C) 2006 by Jens Arnold
  11  *
  12  * This program is free software; you can redistribute it and/or
  13  * modify it under the terms of the GNU General Public License
  14  * as published by the Free Software Foundation; either version 2
  15  * of the License, or (at your option) any later version.
  16  *
  17  * This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
  18  * KIND, either express or implied.
  19  *
  20  ****************************************************************************/
  21
  22 #include "string-extra.h" /* memset16() */
  23
  24 #define LBLOCKSIZE (sizeof(long)/2)
  25 #define UNALIGNED(X)   ((long)X & (sizeof(long) - 1))
  26 #define TOO_SMALL(LEN) ((LEN) < LBLOCKSIZE)
  27
  28 void memset16(void *dst, int val, size_t len)
  29 {
  30 #if defined(PREFER_SIZE_OVER_SPEED) || defined(__OPTIMIZE_SIZE__)
  31     unsigned short *p = (unsigned short *)dst;
  32
  33     while (len--)
  34         *p++ = val;
  35 #else
  36     unsigned short *p = (unsigned short *)dst;
  37     unsigned int i;
  38     unsigned long buffer;
  39     unsigned long *aligned_addr;
  40
  41     if (!TOO_SMALL(len) && !UNALIGNED(dst))
  42     {
  43         aligned_addr = (unsigned long *)dst;
  44
  45         val &= 0xffff;
  46         if (LBLOCKSIZE == 2)
  47         {
  48             buffer = (val << 16) | val;
  49         }
  50         else
  51         {
  52             buffer = 0;
  53             for (i = 0; i < LBLOCKSIZE; i++)
  54             buffer = (buffer << 16) | val;
  55         }
  56
  57         while (len >= LBLOCKSIZE*4)
  58         {
  59             *aligned_addr++ = buffer;
  60             *aligned_addr++ = buffer;
  61             *aligned_addr++ = buffer;
  62             *aligned_addr++ = buffer;
  63             len -= 4*LBLOCKSIZE;
  64         }
  65
  66         while (len >= LBLOCKSIZE)
  67         {
  68             *aligned_addr++ = buffer;
  69             len -= LBLOCKSIZE;
  70         }
  71
  72         p = (unsigned short *)aligned_addr;
  73     }
  74
  75     while (len--)
  76         *p++ = val;
  77 #endif /* not PREFER_SIZE_OVER_SPEED */
  78 }