/*
  Reference Code of a Random Number Generator
  LFSR (Linear Feedback Shift Register):
  an example of 32-bit maximal period Galois LFSR from the following site.
  https://en.wikipedia.org/wiki/Talk:Linear-feedback_shift_register#Simulated_in_simulated_C
*/


static unsigned int lfsr;


void random_generator_reference_init(unsigned int s){
  lfsr = s;
}


unsigned int random_generator_reference(void){
  lfsr = (lfsr >> 1) ^ (-(signed int)(lfsr & 1) & 0xd0000001u); /* taps 32 31 29 1 */
  return lfsr;
}