#!/usr/bin/perl

use warnings;
use strict;

use Inline C => <<'END_OF_C_CODE';

#include <stdint.h>

SV* normalChecksum8(char *b, int n)
{
  int i;
  uint16_t a, bb;

  //Sums bytes 1 to n-1 unsigned to a 2 byte value. Sums quotient and
  //remainder of 256 division.  Again, sums quotient and remainder of
  //256 division.
  for(i = 1, a = 0; i < n; i++)
    a+=(uint16_t)b[i];

  bb = a / 256;
  a = (a - 256 * bb) + bb;
  bb = a / 256;

  return newSVpvf("%d", (a-256*bb)+bb);
}

END_OF_C_CODE

print normalChecksum8("3532",2). "\n";