#include <stdio.h>

unsigned int do_mask (unsigned int v, unsigned int sz)
{
  unsigned int msk;
  if (sz >= 32) {
    return v;
  } else {
    msk = (1 << sz) - 1;
    return (v & msk);
  }
}

void four_copies(unsigned int* buf, unsigned int x)
{
  buf[0] = x;
  buf[1] = x;
  buf[2] = x;
  buf[3] = x;
}

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

  poly_words = n / 32;
  poly_rem = n % 32;
  if (poly_rem > 0) {
    res[poly_words] = do_mask( ~(src[poly_words]), poly_rem );
  }
  while ( poly_words > 0 ) {
    poly_words --;
    res[poly_words] = ~(src[poly_words]);
  }
}

void display_hex_poly (unsigned int n, unsigned int *p)
{
  unsigned int poly_words, poly_rem;

  // display nothing for size 0
  if (n == 0)
    return;

  poly_words = n / 32;
  poly_rem = n % 32;

  if (poly_rem > 0) {
    printf("%08x", do_mask(p[poly_words], poly_rem));
  } else {
    // to make sure there's no leading space
    poly_words --;
    printf("%08x", p[poly_words]);
  }
  while ( poly_words > 0 ) {
    poly_words --;
    printf(" %08x", p[poly_words]);
  }
}

void display_four (unsigned int n, unsigned int w[4], unsigned int *p, char *s)
{
  printf("    n = %08x\n", n);
  printf("    w = %08x %08x %08x %08x\n", w[3], w[2], w[1], w[0]);
  printf("    p = ");
  display_hex_poly(n,p);
  printf("\n");
  printf("    s = %s\n", s);
}

unsigned int popcount(unsigned int* data, unsigned int n)
{
  unsigned int ones = 0;
  unsigned int remaining = n;
  while (remaining > 0)
  {
    unsigned int x = *(data++);
    unsigned int i;
    for (i = 0; i < 32 && remaining > 0; ++i, --remaining)
    {
      if (x & (1 << i))
        ++ones;
    }
  }

  return ones;
}