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

132 lines
3.4 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
Copyright (C) 2013 Mike Hansen
******************************************************************************/
#ifdef T
#include "templates.h"
#include <stdio.h>
#include <stdlib.h>
#include "flint.h"
#include "ulong_extras.h"
static __inline__ int
TEMPLATE(T, mat_pivot) (TEMPLATE(T, mat_t) A, slong * P, slong start_row,
slong col, const TEMPLATE(T, ctx_t) ctx)
{
slong j, t;
TEMPLATE(T, struct) * u;
if (!TEMPLATE(T, is_zero)
(TEMPLATE(T, mat_entry) (A, start_row, col), ctx))
return 1;
for (j = start_row + 1; j < A->r; j++)
{
if (!TEMPLATE(T, is_zero) (TEMPLATE(T, mat_entry) (A, j, col), ctx))
{
u = A->rows[j];
A->rows[j] = A->rows[start_row];
A->rows[start_row] = u;
t = P[j];
P[j] = P[start_row];
P[start_row] = t;
return -1;
}
}
return 0;
}
slong
TEMPLATE(T, mat_lu_classical) (slong * P,
TEMPLATE(T, mat_t) A,
int rank_check, const TEMPLATE(T, ctx_t) ctx)
{
TEMPLATE(T, t) d, e, neg_e;
TEMPLATE(T, struct) ** a;
slong i, m, n, rank, length, row, col;
m = A->r;
n = A->c;
a = A->rows;
rank = row = col = 0;
for (i = 0; i < m; i++)
P[i] = i;
TEMPLATE(T, init) (d, ctx);
TEMPLATE(T, init) (e, ctx);
TEMPLATE(T, init) (neg_e, ctx);
while (row < m && col < n)
{
if (TEMPLATE(T, mat_pivot) (A, P, row, col, ctx) == 0)
{
if (rank_check)
return 0;
col++;
continue;
}
rank++;
TEMPLATE(T, inv) (d, a[row] + col, ctx);
length = n - col - 1;
for (i = row + 1; i < m; i++)
{
TEMPLATE(T, mul) (e, a[i] + col, d, ctx);
if (length != 0)
{
TEMPLATE(T, neg) (neg_e, e, ctx);
_TEMPLATE3(T, vec_scalar_addmul, T) (a[i] + col + 1,
a[row] + col + 1,
length, neg_e, ctx);
}
TEMPLATE(T, zero) (a[i] + col, ctx);
TEMPLATE(T, set) (a[i] + rank - 1, e, ctx);
}
row++;
col++;
}
TEMPLATE(T, clear) (d, ctx);
TEMPLATE(T, clear) (e, ctx);
TEMPLATE(T, clear) (neg_e, ctx);
return rank;
}
#endif