sysdeps/m68k/memcopy.h

   1 /* memcopy.h -- definitions for memory copy functions.  Motorola 68020 version.
   2    Copyright (C) 1991, 1997, 2004 Free Software Foundation, Inc.
   3    This file is part of the GNU C Library.
   4    Contributed by Torbjorn Granlund (tege@sics.se).
   5
   6    The GNU C Library is free software; you can redistribute it and/or
   7    modify it under the terms of the GNU Lesser General Public
   8    License as published by the Free Software Foundation; either
   9    version 2.1 of the License, or (at your option) any later version.
  10
  11    The GNU C Library is distributed in the hope that it will be useful,
  12    but WITHOUT ANY WARRANTY; without even the implied warranty of
  13    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  14    Lesser General Public License for more details.
  15
  16    You should have received a copy of the GNU Lesser General Public
  17    License along with the GNU C Library.  If not, see
  18    <http://www.gnu.org/licenses/>.  */
  19
  20 #include <sysdeps/generic/memcopy.h>
  21
  22 #if     defined(__mc68020__) || defined(mc68020)
  23
  24 #undef  OP_T_THRES
  25 #define OP_T_THRES      16
  26
  27 /* WORD_COPY_FWD and WORD_COPY_BWD are not symmetric on the 68020,
  28    because of its weird instruction overlap characteristics.  */
  29
  30 #undef  WORD_COPY_FWD
  31 #define WORD_COPY_FWD(dst_bp, src_bp, nbytes_left, nbytes)                    \
  32   do                                                                          \
  33     {                                                                         \
  34       size_t __nwords = (nbytes) / sizeof (op_t);                             \
  35       size_t __nblocks = __nwords / 8 + 1;                                    \
  36       dst_bp -= (8 - __nwords % 8) * sizeof (op_t);                           \
  37       src_bp -= (8 - __nwords % 8) * sizeof (op_t);                           \
  38       switch (__nwords % 8)                                                   \
  39         do                                                                    \
  40           {                                                                   \
  41             ((op_t *) dst_bp)[0] = ((op_t *) src_bp)[0];                      \
  42           case 7:                                                             \
  43             ((op_t *) dst_bp)[1] = ((op_t *) src_bp)[1];                      \
  44           case 6:                                                             \
  45             ((op_t *) dst_bp)[2] = ((op_t *) src_bp)[2];                      \
  46           case 5:                                                             \
  47             ((op_t *) dst_bp)[3] = ((op_t *) src_bp)[3];                      \
  48           case 4:                                                             \
  49             ((op_t *) dst_bp)[4] = ((op_t *) src_bp)[4];                      \
  50           case 3:                                                             \
  51             ((op_t *) dst_bp)[5] = ((op_t *) src_bp)[5];                      \
  52           case 2:                                                             \
  53             ((op_t *) dst_bp)[6] = ((op_t *) src_bp)[6];                      \
  54           case 1:                                                             \
  55             ((op_t *) dst_bp)[7] = ((op_t *) src_bp)[7];                      \
  56           case 0:                                                             \
  57             src_bp += 32;                                                     \
  58             dst_bp += 32;                                                     \
  59             __nblocks--;                                                      \
  60           }                                                                   \
  61       while (__nblocks != 0);                                                 \
  62       (nbytes_left) = (nbytes) % sizeof (op_t);                               \
  63     } while (0)
  64
  65 #undef  WORD_COPY_BWD
  66 #define WORD_COPY_BWD(dst_ep, src_ep, nbytes_left, nbytes)                    \
  67   do                                                                          \
  68     {                                                                         \
  69       size_t __nblocks = (nbytes) / 32 + 1;                                   \
  70       op_t *__dst_ep = (op_t *) (dst_ep);                                     \
  71       op_t *__src_ep = (op_t *) (src_ep);                                     \
  72       switch ((nbytes) / sizeof (op_t) % 8)                                   \
  73         do                                                                    \
  74           {                                                                   \
  75             *--__dst_ep = *--__src_ep;                                        \
  76           case 7:                                                             \
  77             *--__dst_ep = *--__src_ep;                                        \
  78           case 6:                                                             \
  79             *--__dst_ep = *--__src_ep;                                        \
  80           case 5:                                                             \
  81             *--__dst_ep = *--__src_ep;                                        \
  82           case 4:                                                             \
  83             *--__dst_ep = *--__src_ep;                                        \
  84           case 3:                                                             \
  85             *--__dst_ep = *--__src_ep;                                        \
  86           case 2:                                                             \
  87             *--__dst_ep = *--__src_ep;                                        \
  88           case 1:                                                             \
  89             *--__dst_ep = *--__src_ep;                                        \
  90           case 0:                                                             \
  91             __nblocks--;                                                      \
  92           }                                                                   \
  93       while (__nblocks != 0);                                                 \
  94       (nbytes_left) = (nbytes) % sizeof (op_t);                               \
  95       (dst_ep) = (unsigned long) __dst_ep;                                    \
  96       (src_ep) = (unsigned long) __src_ep;                                    \
  97     } while (0)
  98
  99 #endif