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  1. /*
  2.  * Copyright (C) 2005 HelenOS project
  3.  * All rights reserved.
  4.  *
  5.  * Redistribution and use in source and binary forms, with or without
  6.  * modification, are permitted provided that the following conditions
  7.  * are met:
  8.  *
  9.  * - Redistributions of source code must retain the above copyright
  10.  *   notice, this list of conditions and the following disclaimer.
  11.  * - Redistributions in binary form must reproduce the above copyright
  12.  *   notice, this list of conditions and the following disclaimer in the
  13.  *   documentation and/or other materials provided with the distribution.
  14.  * - The name of the author may not be used to endorse or promote products
  15.  *   derived from this software without specific prior written permission.
  16.  *
  17.  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
  18.  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
  19.  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
  20.  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
  21.  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
  22.  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
  23.  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
  24.  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  25.  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
  26.  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  27.  */
  28.  
  29. #ifndef __ia32_MEMSTR_H__
  30. #define __ia32_MEMSTR_H__
  31.  
  32. extern void memsetw(__address dst, size_t cnt, __u16 x);
  33. extern void memsetb(__address dst, size_t cnt, __u8 x);
  34.  
  35. extern int memcmp(__address src, __address dst, int cnt);
  36.  
  37. /** Copy memory
  38.  *
  39.  * Copy a given number of bytes (3rd argument)
  40.  * from the memory location defined by 2nd argument
  41.  * to the memory location defined by 1st argument.
  42.  * The memory areas cannot overlap.
  43.  *
  44.  * @param destination
  45.  * @param source
  46.  * @param number of bytes
  47.  * @return destination
  48.  */
  49. static inline void * memcpy(void * dst, const void * src, size_t cnt)
  50. {
  51.         __u32 d0, d1, d2;
  52.  
  53.         __asm__ __volatile__(
  54.                 /* copy all full dwords */
  55.                 "rep movsl\n\t"
  56.                 /* load count again */
  57.                 "movl %4, %%ecx\n\t"
  58.                 /* ecx = ecx mod 4 */
  59.                 "andl $3, %%ecx\n\t"
  60.                 /* are there last <=3 bytes? */
  61.                 "jz 1f\n\t"
  62.                 /* copy last <=3 bytes */
  63.                 "rep movsb\n\t"
  64.                 /* exit from asm block */
  65.                 "1:\n"
  66.                 : "=&c" (d0), "=&D" (d1), "=&S" (d2)
  67.                 : "0" (cnt / 4), "g" (cnt), "1" ((__u32) dst), "2" ((__u32) src)
  68.                 : "memory");
  69.  
  70.         return dst;
  71. }
  72.  
  73.  
  74.  
  75. #endif
  76.