/*---------------------------------------------------------------------------*/
#ifdef UIP_ARCH_IPCHKSUM
u16_t
uip_ipchksum(void)
{
  /* Assumes proper alignement of uip_buf. */
  u16_t *p = (u16_t *)&uip_buf[UIP_LLH_LEN];
  register u16_t sum;

  sum = p[0];
  asmv("add  %[p], %[sum]": [sum] "+r" (sum): [p] "m" (p[1]));
  asmv("addc %[p], %[sum]": [sum] "+r" (sum): [p] "m" (p[2]));
  asmv("addc %[p], %[sum]": [sum] "+r" (sum): [p] "m" (p[3]));
  asmv("addc %[p], %[sum]": [sum] "+r" (sum): [p] "m" (p[4]));
  asmv("addc %[p], %[sum]": [sum] "+r" (sum): [p] "m" (p[5]));
  asmv("addc %[p], %[sum]": [sum] "+r" (sum): [p] "m" (p[6]));
  asmv("addc %[p], %[sum]": [sum] "+r" (sum): [p] "m" (p[7]));
  asmv("addc %[p], %[sum]": [sum] "+r" (sum): [p] "m" (p[8]));
  asmv("addc %[p], %[sum]": [sum] "+r" (sum): [p] "m" (p[9]));

  /* Finally, add the remaining carry bit. */
  asmv("addc #0, %[sum]": [sum] "+r" (sum));

  /* Return sum in network byte order. */
  return (sum == 0) ? 0xffff : sum;
}
#endif
/*---------------------------------------------------------------------------*/