arb/dlog/1modpe.c

40 lines
1.4 KiB
C

/*=============================================================================
This file is part of ARB.
ARB 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.
ARB 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 ARB; if not, write to the Free Software
Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
=============================================================================*/
/******************************************************************************
Copyright (C) 2016 Pascal Molin
******************************************************************************/
#include "dlog.h"
ulong
dlog_1modpe(const dlog_1modpe_t t, ulong b1, ulong p, ulong e, nmod_t pe)
{
if (e == 1)
return 0;
else
{
ulong logb1;
logb1 = dlog_1modpe_mod1p(b1, p, e, t->inv1p, pe);
/* only need mod p^(e-1) */
return nmod_mul(logb1, t->invloga1, pe);
}
}