Function chooseExtension

factory/cfModGcd.cc:420–452

}

static inline
Variable chooseExtension (const Variable & alpha)
{
  int i, m;
  // extension of F_p needed
  if (alpha.level() == 1)
  {
    i= 1;
    m= 2;
  } //extension of F_p(alpha)
  if (alpha.level() != 1)
  {
    i= 4;
    m= degree (getMipo (alpha));
  }
  #ifdef HAVE_FLINT
  nmod_poly_t Irredpoly;
  nmod_poly_init(Irredpoly,getCharacteristic());
  nmod_poly_randtest_monic_irreducible(Irredpoly, FLINTrandom, i*m+1);
  CanonicalForm newMipo=convertnmod_poly_t2FacCF(Irredpoly,Variable(1));
  nmod_poly_clear(Irredpoly);
  #else
  if (fac_NTL_char != getCharacteristic())
  {
    fac_NTL_char= getCharacteristic();
    zz_p::init (getCharacteristic());
  }
  zz_pX NTLIrredpoly;
  BuildIrred (NTLIrredpoly, i*m);
  CanonicalForm newMipo= convertNTLzzpX2CF (NTLIrredpoly, Variable (1));
  #endif
  return rootOf (newMipo);
}

#if defined(HAVE_NTL) || defined(HAVE_FLINT)
CanonicalForm