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C/C++ Source or Header  |  1994-07-18  |  3.2 KB  |  95 lines
  1. /* memcopy.h -- definitions for memory copy functions.  Pentium version.
  2.    Copyright (C) 1994 Free Software Foundation, Inc.
  3.    Contributed by Torbjorn Granlund (tege@sics.se).
  4.  
  5. This file is part of the GNU C Library.
  6.  
  7. The GNU C Library is free software; you can redistribute it and/or
  8. modify it under the terms of the GNU Library General Public License as
  9. published by the Free Software Foundation; either version 2 of the
  10. License, or (at your option) any later version.
  11.  
  12. The GNU C Library is distributed in the hope that it will be useful,
  13. but WITHOUT ANY WARRANTY; without even the implied warranty of
  14. MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  15. Library General Public License for more details.
  16.  
  17. You should have received a copy of the GNU Library General Public
  18. License along with the GNU C Library; see the file COPYING.LIB.  If
  19. not, write to the Free Software Foundation, Inc., 675 Mass Ave,
  20. Cambridge, MA 02139, USA.  */
  21.  
  22. /* Get the i386 definitions.  We will override some of them below.  */
  23. #include_next <memcopy.h>
  24.  
  25.  
  26. /* Written like this, the Pentium pipeline can execute the loop at a
  27.    sustained rate of 2 instructions/clock, or asymptotically 480
  28.    Mbytes/second at 60Mhz.  */
  29.  
  30. #undef    WORD_COPY_FWD
  31. #define WORD_COPY_FWD(dst_bp, src_bp, nbytes_left, nbytes)        \
  32.   do                                    \
  33.     {                                    \
  34.       asm volatile ("subl    $32,%2\n"                \
  35.             "js        2f\n"                    \
  36.             "1:\n"                        \
  37.             "movl    0(%1),%%eax\n"                \
  38.             "movl    4(%1),%%edx\n"                \
  39.             "movl    %%eax,0(%0)\n"                \
  40.             "movl    %%edx,4(%0)\n"                \
  41.             "movl    8(%1),%%eax\n"                \
  42.             "movl    12(%1),%%edx\n"                \
  43.             "movl    %%eax,8(%0)\n"                \
  44.             "movl    %%edx,12(%0)\n"                \
  45.             "movl    16(%1),%%eax\n"                \
  46.             "movl    20(%1),%%edx\n"                \
  47.             "movl    %%eax,16(%0)\n"                \
  48.             "movl    %%edx,20(%0)\n"                \
  49.             "movl    24(%1),%%eax\n"                \
  50.             "movl    28(%1),%%edx\n"                \
  51.             "movl    %%eax,24(%0)\n"                \
  52.             "movl    %%edx,28(%0)\n"                \
  53.             "addl    $32,%1\n"                \
  54.             "addl    $32,%0\n"                \
  55.             "subl    $32,%2\n"                \
  56.             "jns    1b\n"                    \
  57.             "2: addl    $32,%2" :                \
  58.             "=r" (dst_bp), "=r" (src_bp), "=r" (nbytes_left) :    \
  59.             "0" (dst_bp), "1" (src_bp), "2" (nbytes) :        \
  60.             "ax", "dx");                    \
  61.     } while (0)
  62.  
  63. #undef    WORD_COPY_BWD
  64. #define WORD_COPY_BWD(dst_ep, src_ep, nbytes_left, nbytes)        \
  65.   do                                    \
  66.     {                                    \
  67.       asm volatile ("subl    $32,%2\n"                \
  68.             "js        2f\n"                    \
  69.             "1:\n"                        \
  70.             "movl    -4(%1),%%eax\n"                \
  71.             "movl    -8(%1),%%edx\n"                \
  72.             "movl    %%eax,-4(%0)\n"                \
  73.             "movl    %%edx,-8(%0)\n"                \
  74.             "movl    -12(%1),%%eax\n"            \
  75.             "movl    -16(%1),%%edx\n"            \
  76.             "movl    %%eax,-12(%0)\n"            \
  77.             "movl    %%edx,-16(%0)\n"            \
  78.             "movl    -20(%1),%%eax\n"            \
  79.             "movl    -24(%1),%%edx\n"            \
  80.             "movl    %%eax,-20(%0)\n"            \
  81.             "movl    %%edx,-24(%0)\n"            \
  82.             "movl    -28(%1),%%eax\n"            \
  83.             "movl    -32(%1),%%edx\n"            \
  84.             "movl    %%eax,-28(%0)\n"            \
  85.             "movl    %%edx,-32(%0)\n"            \
  86.             "subl    $32,%1\n"                \
  87.             "subl    $32,%0\n"                \
  88.             "subl    $32,%2\n"                \
  89.             "jns    1b\n"                    \
  90.             "2: addl    $32,%2" :                \
  91.             "=r" (dst_bp), "=r" (src_bp), "=r" (nbytes_left) :    \
  92.             "0" (dst_bp), "1" (src_bp), "2" (nbytes) :        \
  93.             "ax", "dx");                    \
  94.     } while (0)
  95.