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

125 lines
3.2 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) 2012 Andres Goens
Copyright (C) 2012 Sebastian Pancratz
Copyright (C) 2013 Mike Hansen
******************************************************************************/
#include <stdio.h>
#include <string.h>
#include "fq_nmod.h"
int _fq_nmod_ctx_init_conway(fq_nmod_ctx_t ctx, const fmpz_t p, slong d, const char *var)
{
char *buf;
FILE *file;
if (fmpz_cmp_ui(p, 109987) > 0)
{
return 0;
}
buf = flint_malloc(832);
file = fopen(FLINT_CPIMPORT, "r");
if (!file)
{
file = fopen("../qadic/CPimport.txt", "r");
if (!file)
{
flint_printf("Exception (fq_nmod_ctx_init_conway). File loading.\n");
abort();
}
}
while (fgets(buf, 832, file))
{
char *tmp = buf;
/* Different prime? */
if (fmpz_cmp_ui(p, atoi(tmp)))
continue;
while (*tmp++ != ' ') ;
/* Same degree? */
if (d == atoi(tmp))
{
nmod_poly_t mod;
slong i;
char *ptr;
nmod_poly_init(mod, fmpz_get_ui(p));
/* Copy the polynomial */
ptr = tmp;
for (i = 0; i < d; i++)
{
int coeff;
while (*ptr++ != ' ') ;
coeff = atoi(ptr);
nmod_poly_set_coeff_ui(mod, i, coeff);
}
nmod_poly_set_coeff_ui(mod, d, 1);
fq_nmod_ctx_init_modulus(ctx, mod, var);
nmod_poly_clear(mod);
fclose(file);
flint_free(buf);
return 1;
}
}
fclose(file);
flint_free(buf);
return 0;
}
void fq_nmod_ctx_init_conway(fq_nmod_ctx_t ctx, const fmpz_t p, slong d, const char *var)
{
int result;
if (fmpz_cmp_ui(p, 109987) > 0)
{
flint_printf("Exception (fq_nmod_ctx_init_conway). Conway polynomials \n");
flint_printf("are only available for primes up to 109987.\n");
abort();
}
result = _fq_nmod_ctx_init_conway(ctx, p, d, var);
if (!result) {
flint_printf("Exception (fq_nmod_ctx_init_conway). The polynomial for \n(p,d) = (");
fmpz_print(p), flint_printf(",%wd) is not present in the database.\n", d);
abort();
}
}