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/*
Copyright (C) 2016 Pascal Molin
This file is part of FLINT.
FLINT is free software: you can redistribute it and/or modify it under
the terms of the GNU Lesser General Public License (LGPL) as published
by the Free Software Foundation; either version 3 of the License, or
(at your option) any later version. See <https://www.gnu.org/licenses/>.
*/
#include "nmod.h"
#include "dlog.h"
ulong
dlog_modpe(const dlog_modpe_t t, ulong b)
{
ulong x;
if (t->p == 2)
return dlog_mod2e(t, b);
x = dlog_precomp(t->modp, b % t->p);
if (t->e > 1)
{
ulong b1, y;
#if 0
b1 = nmod_mul(b, nmod_pow_ui(t->inva, x, t->pe), t->pe);
y = dlog_1modpe(t->modpe.rec, b1, t->p, t->e, t->pe);
y = y % t->pe1;
x = x + (t->p - 1) * y;
#else
b1 = nmod_pow_ui(b, t->p - 1, t->pe);
y = dlog_1modpe(t->modpe, b1, t->p, t->e, t->pe);
y = y % t->pe1;
x = n_submod(x, y % (t->p - 1), t->p - 1);
x = y + t->pe1 * x;
#endif
}
return x;
}