lib/libc/arch/m68k/string/swab.S

   1 /*      $NetBSD: swab.S,v 1.11 2014/03/18 18:20:37 riastradh Exp $      */
   2
   3 #include <machine/asm.h>
   4
   5 ENTRY(swab)
   6         movl    4(%sp),%a0              | source
   7         movl    8(%sp),%a1              | destination
   8         movl    12(%sp),%d0             | count
   9         lsrl    #1,%d0                  | count is in bytes; we need words
  10         jeq     swdone
  11
  12 swloop:
  13 #ifdef __mcoldfire__
  14         movb    (%a0)+,1(%a1)
  15         movb    (%a0)+,(%a1)
  16         addql   #2,%a1
  17 #else
  18         movw    (%a0)+,%d1
  19         rorw    #8,%d1
  20         movw    %d1,(%a1)+
  21 #endif
  22         subql   #1,%d0
  23         jne     swloop
  24
  25 swdone:
  26         rts
  27 END(swab)