memcpy-64.s

   1 .global mymemcpy
   2 .type mymemcpy,@function
   3 mymemcpy:
   4         mov %rdi,%rax
   5         cmp $8,%rdx
   6         jc 1f
   7         test $7,%edi
   8         jz 1f
   9 2:      movsb
  10         dec %rdx
  11         test $7,%edi
  12         jnz 2b
  13 1:      mov %rdx,%rcx
  14         shr $3,%rcx
  15         rep
  16         movsq
  17         and $7,%edx
  18         jz 1f
  19 2:      movsb
  20         dec %edx
  21         jnz 2b
  22 1:      ret