|
Packit |
5c3484 |
/* mpn_toom_eval_dgr3_pm2 -- Evaluate a degree 3 polynomial in +2 and -2
|
|
Packit |
5c3484 |
|
|
Packit |
5c3484 |
Contributed to the GNU project by Niels Möller
|
|
Packit |
5c3484 |
|
|
Packit |
5c3484 |
THE FUNCTION IN THIS FILE IS INTERNAL WITH A MUTABLE INTERFACE. IT IS ONLY
|
|
Packit |
5c3484 |
SAFE TO REACH IT THROUGH DOCUMENTED INTERFACES. IN FACT, IT IS ALMOST
|
|
Packit |
5c3484 |
GUARANTEED THAT IT WILL CHANGE OR DISAPPEAR IN A FUTURE GNU MP RELEASE.
|
|
Packit |
5c3484 |
|
|
Packit |
5c3484 |
Copyright 2009 Free Software Foundation, Inc.
|
|
Packit |
5c3484 |
|
|
Packit |
5c3484 |
This file is part of the GNU MP Library.
|
|
Packit |
5c3484 |
|
|
Packit |
5c3484 |
The GNU MP Library is free software; you can redistribute it and/or modify
|
|
Packit |
5c3484 |
it under the terms of either:
|
|
Packit |
5c3484 |
|
|
Packit |
5c3484 |
* the GNU Lesser General Public License as published by the Free
|
|
Packit |
5c3484 |
Software Foundation; either version 3 of the License, or (at your
|
|
Packit |
5c3484 |
option) any later version.
|
|
Packit |
5c3484 |
|
|
Packit |
5c3484 |
or
|
|
Packit |
5c3484 |
|
|
Packit |
5c3484 |
* the GNU General Public License as published by the Free Software
|
|
Packit |
5c3484 |
Foundation; either version 2 of the License, or (at your option) any
|
|
Packit |
5c3484 |
later version.
|
|
Packit |
5c3484 |
|
|
Packit |
5c3484 |
or both in parallel, as here.
|
|
Packit |
5c3484 |
|
|
Packit |
5c3484 |
The GNU MP Library is distributed in the hope that it will be useful, but
|
|
Packit |
5c3484 |
WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
|
|
Packit |
5c3484 |
or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
|
|
Packit |
5c3484 |
for more details.
|
|
Packit |
5c3484 |
|
|
Packit |
5c3484 |
You should have received copies of the GNU General Public License and the
|
|
Packit |
5c3484 |
GNU Lesser General Public License along with the GNU MP Library. If not,
|
|
Packit |
5c3484 |
see https://www.gnu.org/licenses/. */
|
|
Packit |
5c3484 |
|
|
Packit |
5c3484 |
|
|
Packit |
5c3484 |
#include "gmp.h"
|
|
Packit |
5c3484 |
#include "gmp-impl.h"
|
|
Packit |
5c3484 |
|
|
Packit |
5c3484 |
/* Needs n+1 limbs of temporary storage. */
|
|
Packit |
5c3484 |
int
|
|
Packit |
5c3484 |
mpn_toom_eval_dgr3_pm2 (mp_ptr xp2, mp_ptr xm2,
|
|
Packit |
5c3484 |
mp_srcptr xp, mp_size_t n, mp_size_t x3n, mp_ptr tp)
|
|
Packit |
5c3484 |
{
|
|
Packit |
5c3484 |
mp_limb_t cy;
|
|
Packit |
5c3484 |
int neg;
|
|
Packit |
5c3484 |
|
|
Packit |
5c3484 |
ASSERT (x3n > 0);
|
|
Packit |
5c3484 |
ASSERT (x3n <= n);
|
|
Packit |
5c3484 |
|
|
Packit |
5c3484 |
/* (x0 + 4 * x2) +/- (2 x1 + 8 x_3) */
|
|
Packit |
5c3484 |
#if HAVE_NATIVE_mpn_addlsh_n || HAVE_NATIVE_mpn_addlsh2_n
|
|
Packit |
5c3484 |
#if HAVE_NATIVE_mpn_addlsh2_n
|
|
Packit |
5c3484 |
xp2[n] = mpn_addlsh2_n (xp2, xp, xp + 2*n, n);
|
|
Packit |
5c3484 |
|
|
Packit |
5c3484 |
cy = mpn_addlsh2_n (tp, xp + n, xp + 3*n, x3n);
|
|
Packit |
5c3484 |
#else /* HAVE_NATIVE_mpn_addlsh_n */
|
|
Packit |
5c3484 |
xp2[n] = mpn_addlsh_n (xp2, xp, xp + 2*n, n, 2);
|
|
Packit |
5c3484 |
|
|
Packit |
5c3484 |
cy = mpn_addlsh_n (tp, xp + n, xp + 3*n, x3n, 2);
|
|
Packit |
5c3484 |
#endif
|
|
Packit |
5c3484 |
if (x3n < n)
|
|
Packit |
5c3484 |
cy = mpn_add_1 (tp + x3n, xp + n + x3n, n - x3n, cy);
|
|
Packit |
5c3484 |
tp[n] = cy;
|
|
Packit |
5c3484 |
#else
|
|
Packit |
5c3484 |
cy = mpn_lshift (tp, xp + 2*n, n, 2);
|
|
Packit |
5c3484 |
xp2[n] = cy + mpn_add_n (xp2, tp, xp, n);
|
|
Packit |
5c3484 |
|
|
Packit |
5c3484 |
tp[x3n] = mpn_lshift (tp, xp + 3*n, x3n, 2);
|
|
Packit |
5c3484 |
if (x3n < n)
|
|
Packit |
5c3484 |
tp[n] = mpn_add (tp, xp + n, n, tp, x3n + 1);
|
|
Packit |
5c3484 |
else
|
|
Packit |
5c3484 |
tp[n] += mpn_add_n (tp, xp + n, tp, n);
|
|
Packit |
5c3484 |
#endif
|
|
Packit |
5c3484 |
mpn_lshift (tp, tp, n+1, 1);
|
|
Packit |
5c3484 |
|
|
Packit |
5c3484 |
neg = (mpn_cmp (xp2, tp, n + 1) < 0) ? ~0 : 0;
|
|
Packit |
5c3484 |
|
|
Packit |
5c3484 |
#if HAVE_NATIVE_mpn_add_n_sub_n
|
|
Packit |
5c3484 |
if (neg)
|
|
Packit |
5c3484 |
mpn_add_n_sub_n (xp2, xm2, tp, xp2, n + 1);
|
|
Packit |
5c3484 |
else
|
|
Packit |
5c3484 |
mpn_add_n_sub_n (xp2, xm2, xp2, tp, n + 1);
|
|
Packit |
5c3484 |
#else
|
|
Packit |
5c3484 |
if (neg)
|
|
Packit |
5c3484 |
mpn_sub_n (xm2, tp, xp2, n + 1);
|
|
Packit |
5c3484 |
else
|
|
Packit |
5c3484 |
mpn_sub_n (xm2, xp2, tp, n + 1);
|
|
Packit |
5c3484 |
|
|
Packit |
5c3484 |
mpn_add_n (xp2, xp2, tp, n + 1);
|
|
Packit |
5c3484 |
#endif
|
|
Packit |
5c3484 |
|
|
Packit |
5c3484 |
ASSERT (xp2[n] < 15);
|
|
Packit |
5c3484 |
ASSERT (xm2[n] < 10);
|
|
Packit |
5c3484 |
|
|
Packit |
5c3484 |
return neg;
|
|
Packit |
5c3484 |
}
|