common/lib/libc/arch/x86_64/string/bcmp.S

   1 #include <machine/asm.h>
   2
   3 #if defined(LIBC_SCCS)
   4         RCSID("$NetBSD: bcmp.S,v 1.2 2007/11/12 18:41:59 ad Exp $")
   5 #endif
   6
   7 ENTRY(bcmp)
   8         xorl    %eax,%eax               /* clear return value */
   9
  10         movq    %rdx,%rcx               /* compare by words */
  11         shrq    $3,%rcx
  12         repe
  13         cmpsq
  14         jne     L1
  15
  16         movq    %rdx,%rcx               /* compare remainder by bytes */
  17         andq    $7,%rcx
  18         repe
  19         cmpsb
  20         je      L2
  21
  22 L1:     incl    %eax
  23 L2:     ret