toolchain/gcc/newlib/libc/machine/m68k/strcpy.c

   1 /*
   2  *  C library strcpy routine
   3  *
   4  *  This routine has been optimized for the CPU32+.
   5  *  It should run on all 68k machines.
   6  *
   7  *  W. Eric Norum
   8  *  Saskatchewan Accelerator Laboratory
   9  *  University of Saskatchewan
  10  *  Saskatoon, Saskatchewan, CANADA
  11  *  eric@skatter.usask.ca
  12  */
  13
  14 #include <string.h>
  15
  16 /*
  17  * Copy bytes using CPU32+ loop mode if possible
  18  */
  19
  20 char *
  21 strcpy (char *to, const char *from)
  22 {
  23         char *pto = to;
  24         unsigned int n = 0xFFFF;
  25
  26         asm volatile ("1:\n"
  27              "\tmove.b (%0)+,(%1)+\n"
  28 #if defined(__mcpu32__)
  29              "\tdbeq %2,1b\n"
  30 #endif
  31              "\tbne.b 1b\n" :
  32                 "=a" (from), "=a" (pto), "=d" (n) :
  33                  "0" (from),  "1" (pto), "2" (n) :
  34                  "cc", "memory");
  35         return to;
  36 }