pqc/external/flint-2.4.3/fmpz_mat/mul.c

79 lines
2.1 KiB
C
Raw Normal View History

2014-05-18 22:03:37 +00:00
/*=============================================================================
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) 2010,2011 Fredrik Johansson
******************************************************************************/
#include "fmpz_mat.h"
void
fmpz_mat_mul(fmpz_mat_t C, const fmpz_mat_t A, const fmpz_mat_t B)
{
slong dim, m, n, k;
m = A->r;
n = A->c;
k = B->c;
if (C == A || C == B)
{
fmpz_mat_t t;
fmpz_mat_init(t, m, k);
fmpz_mat_mul(t, A, B);
fmpz_mat_swap(C, t);
fmpz_mat_clear(t);
return;
}
dim = FLINT_MIN(FLINT_MIN(m, n), k);
if (dim < 12)
{
/* The inline version only benefits from large n */
if (n <= 2)
fmpz_mat_mul_classical(C, A, B);
else
fmpz_mat_mul_classical_inline(C, A, B);
}
else
{
slong ab, bb, bits;
ab = fmpz_mat_max_bits(A);
bb = fmpz_mat_max_bits(B);
ab = FLINT_ABS(ab);
bb = FLINT_ABS(bb);
bits = ab + bb + FLINT_BIT_COUNT(n) + 1;
if (5*(ab + bb) > dim * dim || (bits > FLINT_BITS - 3 && dim < 60))
{
fmpz_mat_mul_classical_inline(C, A, B);
}
else
{
_fmpz_mat_mul_multi_mod(C, A, B, bits);
}
}
}