arch/m68k/lib/memcpy.c

   1 #include <linux/types.h>
   2
   3 void * memcpy(void * to, const void * from, size_t n)
   4 {
   5   void *xto = to;
   6   size_t temp, temp1;
   7
   8   if (!n)
   9     return xto;
  10   if ((long) to & 1)
  11     {
  12       char *cto = to;
  13       const char *cfrom = from;
  14       *cto++ = *cfrom++;
  15       to = cto;
  16       from = cfrom;
  17       n--;
  18     }
  19   if (n > 2 && (long) to & 2)
  20     {
  21       short *sto = to;
  22       const short *sfrom = from;
  23       *sto++ = *sfrom++;
  24       to = sto;
  25       from = sfrom;
  26       n -= 2;
  27     }
  28   temp = n >> 2;
  29   if (temp)
  30     {
  31       long *lto = to;
  32       const long *lfrom = from;
  33
  34       __asm__ __volatile__("movel %2,%3\n\t"
  35                            "andw  #7,%3\n\t"
  36                            "lsrl  #3,%2\n\t"
  37                            "negw  %3\n\t"
  38                            "jmp   %%pc@(1f,%3:w:2)\n\t"
  39                            "4:\t"
  40                            "movel %0@+,%1@+\n\t"
  41                            "movel %0@+,%1@+\n\t"
  42                            "movel %0@+,%1@+\n\t"
  43                            "movel %0@+,%1@+\n\t"
  44                            "movel %0@+,%1@+\n\t"
  45                            "movel %0@+,%1@+\n\t"
  46                            "movel %0@+,%1@+\n\t"
  47                            "movel %0@+,%1@+\n\t"
  48                            "1:\t"
  49                            "dbra  %2,4b\n\t"
  50                            "clrw  %2\n\t"
  51                            "subql #1,%2\n\t"
  52                            "jpl   4b\n\t"
  53                            : "=a" (lfrom), "=a" (lto), "=d" (temp),
  54                            "=&d" (temp1)
  55                            : "0" (lfrom), "1" (lto), "2" (temp)
  56                            );
  57       to = lto;
  58       from = lfrom;
  59     }
  60   if (n & 2)
  61     {
  62       short *sto = to;
  63       const short *sfrom = from;
  64       *sto++ = *sfrom++;
  65       to = sto;
  66       from = sfrom;
  67     }
  68   if (n & 1)
  69     {
  70       char *cto = to;
  71       const char *cfrom = from;
  72       *cto = *cfrom;
  73     }
  74   return xto;
  75 }