unsigned int do_mask (unsigned int v, unsigned int sz);

void four_copies(unsigned int* buf, unsigned int x);

void invert_poly(unsigned int* res, unsigned int* src, unsigned int n);

void display_four(unsigned int n, unsigned int w[4], unsigned int *p, char *s);
void display_hex_poly (unsigned int n, unsigned int *p);

unsigned int popcount(unsigned int* data, unsigned int n);