home *** CD-ROM | disk | FTP | other *** search
/ Linux Cubed Series 4: GNU Archives / Linux Cubed Series 4 - GNU Archives.iso / gnu / glibc-1.09 / glibc-1 / glibc-1.09.1 / sysdeps / i386 / memcopy.h < prev    next >
Encoding:
C/C++ Source or Header  |  1994-07-18  |  3.2 KB  |  87 lines
  1. /* memcopy.h -- definitions for memory copy functions.  i386 version.
  2.    Copyright (C) 1991 Free Software Foundation, Inc.
  3.    Contributed by Torbjorn Granlund (tege@sics.se).
  4.  
  5. The GNU C Library is free software; you can redistribute it and/or
  6. modify it under the terms of the GNU Library General Public License as
  7. published by the Free Software Foundation; either version 2 of the
  8. License, or (at your option) any later version.
  9.  
  10. The GNU C Library is distributed in the hope that it will be useful,
  11. but WITHOUT ANY WARRANTY; without even the implied warranty of
  12. MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  13. Library General Public License for more details.
  14.  
  15. You should have received a copy of the GNU Library General Public
  16. License along with the GNU C Library; see the file COPYING.LIB.  If
  17. not, write to the Free Software Foundation, Inc., 675 Mass Ave,
  18. Cambridge, MA 02139, USA.  */
  19.  
  20. #include <sysdeps/generic/memcopy.h>
  21.  
  22. #undef    OP_T_THRES
  23. #define    OP_T_THRES    8
  24.  
  25. #undef    BYTE_COPY_FWD
  26. #define BYTE_COPY_FWD(dst_bp, src_bp, nbytes)                      \
  27.   asm volatile(/* Clear the direction flag, so copying goes forward.  */      \
  28.            "cld\n"                                  \
  29.            /* Copy bytes.  */                          \
  30.            "rep\n"                                  \
  31.            "movsb" :                              \
  32.            "=D" (dst_bp), "=S" (src_bp) :                      \
  33.            "0" (dst_bp), "1" (src_bp), "c" (nbytes) :              \
  34.            "cx")
  35.  
  36. #undef    BYTE_COPY_BWD
  37. #define BYTE_COPY_BWD(dst_ep, src_ep, nbytes)                      \
  38.   do                                          \
  39.     {                                          \
  40.       asm volatile(/* Set the direction flag, so copying goes backwards.  */  \
  41.            "std\n"                              \
  42.            /* Copy bytes.  */                          \
  43.            "rep\n"                              \
  44.            "movsb\n"                              \
  45.            /* Clear the dir flag.  Convention says it should be 0. */ \
  46.            "cld" :                              \
  47.            "=D" (dst_ep), "=S" (src_ep) :                  \
  48.            "0" (dst_ep - 1), "1" (src_ep - 1), "c" (nbytes) :          \
  49.            "cx");                              \
  50.       dst_ep += 1;                                  \
  51.       src_ep += 1;                                  \
  52.     } while (0)
  53.  
  54. #undef    WORD_COPY_FWD
  55. #define WORD_COPY_FWD(dst_bp, src_bp, nbytes_left, nbytes)              \
  56.   do                                          \
  57.     {                                          \
  58.       asm volatile(/* Clear the direction flag, so copying goes forward.  */  \
  59.            "cld\n"                              \
  60.            /* Copy longwords.  */                      \
  61.            "rep\n"                              \
  62.            "movsl" :                              \
  63.            "=D" (dst_bp), "=S" (src_bp) :                  \
  64.            "0" (dst_bp), "1" (src_bp), "c" ((nbytes) / 4) :          \
  65.            "cx");                              \
  66.       (nbytes_left) = (nbytes) % 4;                          \
  67.     } while (0)
  68.  
  69. #undef    WORD_COPY_BWD
  70. #define WORD_COPY_BWD(dst_ep, src_ep, nbytes_left, nbytes)              \
  71.   do                                          \
  72.     {                                          \
  73.       asm volatile(/* Set the direction flag, so copying goes backwards.  */  \
  74.            "std\n"                              \
  75.            /* Copy longwords.  */                      \
  76.            "rep\n"                              \
  77.            "movsl\n"                              \
  78.            /* Clear the dir flag.  Convention says it should be 0. */ \
  79.            "cld" :                              \
  80.            "=D" (dst_ep), "=S" (src_ep) :                  \
  81.            "0" (dst_ep - 4), "1" (src_ep - 4), "c" ((nbytes) / 4) :   \
  82.            "cx");                              \
  83.       dst_ep += 4;                                  \
  84.       src_ep += 4;                                  \
  85.       (nbytes_left) = (nbytes) % 4;                          \
  86.     } while (0)
  87.