subtract_multiple()

void M2::ARingZZpFlint::subtract_multiple ( ElementType & result, ElementType a, ElementType b ) const

inline

Definition at line 201 of file aring-zzp-flint.hpp.

  {
    ElementType a1 = nmod_neg(a, mModulus);
 
    // the code below was an attempt to prevent flint from calling the
    // version of the general multiply code if the product of the two flint
    // integers always fits in a single limb.  Speedup was not significant in testing.
 
    //if (mModulus.norm >= FLINT_BITS/2) /* addmul will fit in a limb */
    //{
    //   mp_limb_t ab_hi, ab_lo;
    //   umul_ppmm(ab_hi, ab_lo, a1, b); // a_hi is not needed in this case
    //   ab_lo = nmod_add(result, ab_lo, mModulus);
    //   NMOD_RED(result,ab_lo,mModulus);
    //}
    //else // product does not fit in a single limb
    
    NMOD_ADDMUL(result, a1, b, mModulus);
  }

References mModulus, and result().