test-mask.c

#include <stdio.h>

int main(){
  int i = 0;
  int a = 23;
  int b = 3;

  i += a;
  i = i << 5;
  i += b;

  printf("%d\n", i);


  int c = i & 0x1F; // == b
  int d = i >> 5;

  if(c != b){ printf("Errore\n"); }
  if(a != d){ printf("Errore 2\n"); }

  printf("%d - %d", c, d);
}