64 lines
1.8 KiB
C
64 lines
1.8 KiB
C
/*=============================================================================
|
|
|
|
This file is part of FLINT.
|
|
|
|
FLINT is free software; you can redistribute it and/or modify
|
|
it under the terms of the GNU General Public License as published by
|
|
the Free Software Foundation; either version 2 of the License, or
|
|
(at your option) any later version.
|
|
|
|
FLINT is distributed in the hope that it will be useful,
|
|
but WITHOUT ANY WARRANTY; without even the implied warranty of
|
|
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
|
|
GNU General Public License for more details.
|
|
|
|
You should have received a copy of the GNU General Public License
|
|
along with FLINT; if not, write to the Free Software
|
|
Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
|
|
|
|
=============================================================================*/
|
|
/******************************************************************************
|
|
|
|
Copyright (C) 2010 William Hart
|
|
|
|
******************************************************************************/
|
|
|
|
#include <gmp.h>
|
|
#include "flint.h"
|
|
#include "ulong_extras.h"
|
|
#include "nmod_poly.h"
|
|
|
|
void _nmod_poly_derivative(mp_ptr x_prime, mp_srcptr x, slong len, nmod_t mod)
|
|
{
|
|
slong j;
|
|
mp_limb_t k = 1;
|
|
|
|
for (j = 1; j < len; j++)
|
|
{
|
|
if (k <= 1)
|
|
x_prime[j - 1] = k == 0 ? WORD(0) : x[j];
|
|
else
|
|
x_prime[j - 1] = n_mulmod2_preinv(x[j], k, mod.n, mod.ninv);
|
|
|
|
if (++k == mod.n) k = WORD(0);
|
|
}
|
|
|
|
}
|
|
|
|
void nmod_poly_derivative(nmod_poly_t x_prime, const nmod_poly_t x)
|
|
{
|
|
if (x->length <= 1)
|
|
{
|
|
nmod_poly_zero(x_prime);
|
|
return;
|
|
}
|
|
|
|
nmod_poly_fit_length(x_prime, x->length - 1);
|
|
|
|
_nmod_poly_derivative(x_prime->coeffs, x->coeffs, x->length, x->mod);
|
|
|
|
x_prime->length = x->length - 1;
|
|
_nmod_poly_normalise(x_prime);
|
|
}
|
|
|