pqc/external/flint-2.4.3/fmpz_mat/mul_classical_inline.c
2014-05-24 23:16:06 +02:00

132 lines
4.0 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) 2011 Fredrik Johansson
******************************************************************************/
#include "fmpz_mat.h"
#include "longlong.h"
void
fmpz_mat_mul_classical_inline(fmpz_mat_t C, const fmpz_mat_t A,
const fmpz_mat_t B)
{
slong ar, bc, br;
slong i, j, k;
fmpz a, b;
mpz_t t;
mp_limb_t au, bu;
mp_limb_t pos[3];
mp_limb_t neg[3];
ar = A->r;
br = B->r;
bc = B->c;
mpz_init(t);
for (i = 0; i < ar; i++)
{
for (j = 0; j < bc; j++)
{
flint_mpz_set_ui(t, UWORD(0));
pos[2] = pos[1] = pos[0] = neg[2] = neg[1] = neg[0] = UWORD(0);
for (k = 0; k < br; k++)
{
a = A->rows[i][k];
b = B->rows[k][j];
if (a == 0 || b == 0)
continue;
if (!COEFF_IS_MPZ(a)) /* a is small */
{
if (!COEFF_IS_MPZ(b)) /* both are small */
{
au = FLINT_ABS(a);
bu = FLINT_ABS(b);
umul_ppmm(au, bu, au, bu);
if ((a ^ b) >= WORD(0))
add_sssaaaaaa(pos[2], pos[1], pos[0],
pos[2], pos[1], pos[0], 0, au, bu);
else
add_sssaaaaaa(neg[2], neg[1], neg[0],
neg[2], neg[1], neg[0], 0, au, bu);
}
else
{
if (a >= 0)
flint_mpz_addmul_ui(t, COEFF_TO_PTR(b), a);
else
flint_mpz_submul_ui(t, COEFF_TO_PTR(b), -a);
}
}
else if (!COEFF_IS_MPZ(b)) /* b is small */
{
if (b >= 0)
flint_mpz_addmul_ui(t, COEFF_TO_PTR(a), b);
else
flint_mpz_submul_ui(t, COEFF_TO_PTR(a), -b);
}
else
{
mpz_addmul(t, COEFF_TO_PTR(a), COEFF_TO_PTR(b));
}
}
if (mpz_sgn(t) != 0 || pos[2] || neg[2] || pos[1] || neg[1])
{
__mpz_struct r;
r._mp_size = pos[2] ? 3 : (pos[1] ? 2 : pos[0] != 0);
r._mp_alloc = r._mp_size;
r._mp_d = pos;
mpz_add(t, t, &r);
r._mp_size = neg[2] ? 3 : (neg[1] ? 2 : neg[0] != 0);
r._mp_alloc = r._mp_size;
r._mp_d = neg;
mpz_sub(t, t, &r);
fmpz_set_mpz(fmpz_mat_entry(C, i, j), t);
}
else
{
if (neg[0] > pos[0])
fmpz_neg_ui(fmpz_mat_entry(C, i, j), neg[0] - pos[0]);
else
fmpz_set_ui(fmpz_mat_entry(C, i, j), pos[0] - neg[0]);
}
}
}
mpz_clear(t);
}