pqc/external/flint-2.4.3/fq_zech/pow.c

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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) 2013 Mike Hansen
******************************************************************************/
#include "fq_zech.h"
void
fq_zech_pow(fq_zech_t rop, const fq_zech_t op, const fmpz_t e,
const fq_zech_ctx_t ctx)
{
if (fmpz_sgn(e) < 0)
{
flint_printf("Exception (fq_zech_pow). e < 0.\n");
abort();
}
if (fmpz_is_zero(e))
{
fq_zech_one(rop, ctx);
}
else if (fq_zech_is_zero(op, ctx))
{
fq_zech_zero(rop, ctx);
}
else if (fmpz_is_one(e))
{
fq_zech_set(rop, op, ctx);
}
else
{
fmpz_t new_e;
fmpz_init(new_e);
fmpz_mul_ui(new_e, e, op->value);
fmpz_mod_ui(new_e, new_e, ctx->qm1);
rop->value = fmpz_get_ui(new_e);
fmpz_clear(new_e);
}
}
/* TODO: Move into separate function and optimize */
void fq_zech_pow_ui(fq_zech_t rop, const fq_zech_t op,
const ulong e, const fq_zech_ctx_t ctx)
{
fmpz_t exp;
fmpz_init_set_ui(exp, e);
fq_zech_pow(rop, op, exp, ctx);
fmpz_clear(exp);
}