#int memcmp(const void *data, const void *base, size_t sz)
#{
#  const uint8_t *p = (const uint8_t*)data;
#  const uint8_t *q = (const uint8_t*)base;
#
#  while (sz-- > 0)
#  {
#    int c = *p++ - *q++;
#    if (c != 0)
#      return c;
#  }
#  return 0;
#}

# ( p1 p2 sz -- diff )
memcmp:
  jump .nonempty rel ne
  drop2
  immed 0
  nip return     # ( 0 // )
.nonempty:
  push
  dup
  push
  swap
  dup
  push           # ( p2 p1 // p1 p2 sz )
  load byte
  swap
  load byte      # ( [p1] [p2] // p1 p2 sz )
  sub
  jump .zero rel eq
  rdrop
  rdrop
  rdrop
  return         # ( diff // )
.zero:           # ( diff // p1 p2 sz )
  drop
  pop
  immed 1
  add
  pop
  immed 1
  add
  pop
  immed 1
  sub
  jump memcpy    # ( p1+1 p2+1 sz-1 // )