arch/m68k/lib/memcpy.c

   1 /*
   2  * This file is subject to the terms and conditions of the GNU General Public
   3  * License.  See the file COPYING in the main directory of this archive
   4  * for more details.
   5  */
   6
   7 #include <linux/module.h>
   8 #include <linux/string.h>
   9
  10 void *memcpy(void *to, const void *from, size_t n)
  11 {
  12         void *xto = to;
  13         size_t temp, temp1;
  14
  15         if (!n)
  16                 return xto;
  17         if ((long)to & 1) {
  18                 char *cto = to;
  19                 const char *cfrom = from;
  20                 *cto++ = *cfrom++;
  21                 to = cto;
  22                 from = cfrom;
  23                 n--;
  24         }
  25 #if defined(CONFIG_M68000)
  26         if ((long)from & 1) {
  27                 char *cto = to;
  28                 const char *cfrom = from;
  29                 for (; n; n--)
  30                         *cto++ = *cfrom++;
  31                 return xto;
  32         }
  33 #endif
  34         if (n > 2 && (long)to & 2) {
  35                 short *sto = to;
  36                 const short *sfrom = from;
  37                 *sto++ = *sfrom++;
  38                 to = sto;
  39                 from = sfrom;
  40                 n -= 2;
  41         }
  42         temp = n >> 2;
  43         if (temp) {
  44                 long *lto = to;
  45                 const long *lfrom = from;
  46 #if defined(CONFIG_M68000) || defined(CONFIG_COLDFIRE)
  47                 for (; temp; temp--)
  48                         *lto++ = *lfrom++;
  49 #else
  50                 asm volatile (
  51                         "       movel %2,%3\n"
  52                         "       andw  #7,%3\n"
  53                         "       lsrl  #3,%2\n"
  54                         "       negw  %3\n"
  55                         "       jmp   %%pc@(1f,%3:w:2)\n"
  56                         "4:     movel %0@+,%1@+\n"
  57                         "       movel %0@+,%1@+\n"
  58                         "       movel %0@+,%1@+\n"
  59                         "       movel %0@+,%1@+\n"
  60                         "       movel %0@+,%1@+\n"
  61                         "       movel %0@+,%1@+\n"
  62                         "       movel %0@+,%1@+\n"
  63                         "       movel %0@+,%1@+\n"
  64                         "1:     dbra  %2,4b\n"
  65                         "       clrw  %2\n"
  66                         "       subql #1,%2\n"
  67                         "       jpl   4b"
  68                         : "=a" (lfrom), "=a" (lto), "=d" (temp), "=&d" (temp1)
  69                         : "0" (lfrom), "1" (lto), "2" (temp));
  70 #endif
  71                 to = lto;
  72                 from = lfrom;
  73         }
  74         if (n & 2) {
  75                 short *sto = to;
  76                 const short *sfrom = from;
  77                 *sto++ = *sfrom++;
  78                 to = sto;
  79                 from = sfrom;
  80         }
  81         if (n & 1) {
  82                 char *cto = to;
  83                 const char *cfrom = from;
  84                 *cto = *cfrom;
  85         }
  86         return xto;
  87 }
  88 EXPORT_SYMBOL(memcpy);