Subversion Repositories HelenOS

Rev

Rev 363 | Go to most recent revision | Blame | Last modification | View Log | Download | RSS feed

  1. /*
  2.  * Copyright (C) 2005 Sergey Bondari
  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. /** Copy memory
  36.  *
  37.  * Copy a given number of bytes (3rd argument)
  38.  * from the memory location defined by 2nd argument
  39.  * to the memory location defined by 1st argument.
  40.  * The memory areas cannot overlap.
  41.  *
  42.  * @param destination
  43.  * @param source
  44.  * @param number of bytes
  45.  * @return destination
  46.  */
  47. static inline void * memcpy(void * dst, const void * src, size_t cnt)
  48. {
  49.         __u32 d0, d1, d2;
  50.  
  51.         __asm__ __volatile__(
  52.                 /* copy all full dwords */
  53.                 "rep movsl\n\t"
  54.                 /* load count again */
  55.                 "movl %4, %%ecx\n\t"
  56.                 /* ecx = ecx mod 4 */
  57.                 "andl $3, %%ecx\n\t"
  58.                 /* are there last <=3 bytes? */
  59.                 "jz 1f\n\t"
  60.                 /* copy last <=3 bytes */
  61.                 "rep movsb\n\t"
  62.                 /* exit from asm block */
  63.                 "1:\n"
  64.                 : "=&c" (d0), "=&D" (d1), "=&S" (d2)
  65.                 : "0" (cnt / 4), "g" (cnt), "1" ((__u32) dst), "2" ((__u32) src)
  66.                 : "memory");
  67.  
  68.         return dst;
  69. }
  70.  
  71.  
  72. /** Compare memory
  73.  *
  74.  * Compare a given number of bytes (3rd argument)
  75.  * at memory locations defined by 1st and 2nd argument
  76.  * for equality. If memory is equal, returns 0.
  77.  *
  78.  * @param pointer 1
  79.  * @param pointer 2
  80.  * @param number of bytes
  81.  * @return 0 on match or non-zero if different
  82.  */
  83. static inline int memcmp(const void * mem1, const void * mem2, size_t cnt)
  84. {
  85.     __u32 d0, d1, d2;
  86.     int ret;
  87.    
  88.     __asm__ (
  89.         "repe cmpsb\n\t"
  90.         "je 1f\n\t"
  91.         "movl %3, %0\n\t"
  92.         "addl $1, %0\n\t"
  93.         "1:\n"
  94.         : "=a" (ret), "=%S" (d0), "=&D" (d1), "=&c" (d2)
  95.         : "0" (0), "1" (mem1), "2" (mem2), "3" (cnt)
  96.     );
  97.    
  98.     return ret;
  99. }
  100.  
  101. #endif
  102.