pqc/external/flint-2.4.3/padic/set_ui.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) 2011, 2012 Sebastian Pancratz
******************************************************************************/
#include "padic.h"
void padic_set_ui(padic_t rop, ulong op, const padic_ctx_t ctx)
{
if (op == 0)
{
padic_zero(rop);
}
else if (fmpz_cmp_ui(ctx->p, op) > 0)
{
fmpz_set_ui(padic_unit(rop), op);
padic_val(rop) = 0;
}
else
{
ulong p = fmpz_get_ui(ctx->p), q, r;
/* Remove factors of p */
padic_val(rop) = 0;
r = n_divrem2_precomp(&q, op, p, ctx->pinv);
while (r == 0)
{
op = q;
padic_val(rop)++;
r = n_divrem2_precomp(&q, op, p, ctx->pinv);
}
fmpz_set_ui(padic_unit(rop), op);
_padic_reduce(rop, ctx);
}
}