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, write to the Free
  18    Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
  19    02111-1307 USA.  */
  20
  21 #include <sysdeps/generic/memcopy.h>
  22
  23 #if     defined(__mc68020__) || defined(mc68020)
  24
  25 #undef  OP_T_THRES
  26 #define OP_T_THRES      16
  27
  28 /* WORD_COPY_FWD and WORD_COPY_BWD are not symmetric on the 68020,
  29    because of its weird instruction overlap characteristics.  */
  30
  31 #undef  WORD_COPY_FWD
  32 #define WORD_COPY_FWD(dst_bp, src_bp, nbytes_left, nbytes)                    \
  33   do                                                                          \
  34     {                                                                         \
  35       size_t __nwords = (nbytes) / sizeof (op_t);                             \
  36       size_t __nblocks = __nwords / 8 + 1;                                    \
  37       dst_bp -= (8 - __nwords % 8) * sizeof (op_t);                           \
  38       src_bp -= (8 - __nwords % 8) * sizeof (op_t);                           \
  39       switch (__nwords % 8)                                                   \
  40         do                                                                    \
  41           {                                                                   \
  42             ((op_t *) dst_bp)[0] = ((op_t *) src_bp)[0];                      \
  43           case 7:                                                             \
  44             ((op_t *) dst_bp)[1] = ((op_t *) src_bp)[1];                      \
  45           case 6:                                                             \
  46             ((op_t *) dst_bp)[2] = ((op_t *) src_bp)[2];                      \
  47           case 5:                                                             \
  48             ((op_t *) dst_bp)[3] = ((op_t *) src_bp)[3];                      \
  49           case 4:                                                             \
  50             ((op_t *) dst_bp)[4] = ((op_t *) src_bp)[4];                      \
  51           case 3:                                                             \
  52             ((op_t *) dst_bp)[5] = ((op_t *) src_bp)[5];                      \
  53           case 2:                                                             \
  54             ((op_t *) dst_bp)[6] = ((op_t *) src_bp)[6];                      \
  55           case 1:                                                             \
  56             ((op_t *) dst_bp)[7] = ((op_t *) src_bp)[7];                      \
  57           case 0:                                                             \
  58             src_bp += 32;                                                     \
  59             dst_bp += 32;                                                     \
  60             __nblocks--;                                                      \
  61           }                                                                   \
  62       while (__nblocks != 0);                                                 \
  63       (nbytes_left) = (nbytes) % sizeof (op_t);                               \
  64     } while (0)
  65
  66 #undef  WORD_COPY_BWD
  67 #define WORD_COPY_BWD(dst_ep, src_ep, nbytes_left, nbytes)                    \
  68   do                                                                          \
  69     {                                                                         \
  70       size_t __nblocks = (nbytes) / 32 + 1;                                   \
  71       op_t *__dst_ep = (op_t *) (dst_ep);                                     \
  72       op_t *__src_ep = (op_t *) (src_ep);                                     \
  73       switch ((nbytes) / sizeof (op_t) % 8)                                   \
  74         do                                                                    \
  75           {                                                                   \
  76             *--__dst_ep = *--__src_ep;                                        \
  77           case 7:                                                             \
  78             *--__dst_ep = *--__src_ep;                                        \
  79           case 6:                                                             \
  80             *--__dst_ep = *--__src_ep;                                        \
  81           case 5:                                                             \
  82             *--__dst_ep = *--__src_ep;                                        \
  83           case 4:                                                             \
  84             *--__dst_ep = *--__src_ep;                                        \
  85           case 3:                                                             \
  86             *--__dst_ep = *--__src_ep;                                        \
  87           case 2:                                                             \
  88             *--__dst_ep = *--__src_ep;                                        \
  89           case 1:                                                             \
  90             *--__dst_ep = *--__src_ep;                                        \
  91           case 0:                                                             \
  92             __nblocks--;                                                      \
  93           }                                                                   \
  94       while (__nblocks != 0);                                                 \
  95       (nbytes_left) = (nbytes) % sizeof (op_t);                               \
  96       (dst_ep) = (unsigned long) __dst_ep;                                    \
  97       (src_ep) = (unsigned long) __src_ep;                                    \
  98     } while (0)
  99
 100 #endif