arb/dlog/1modpe_mod1p.c
Tommy Hofmann 6bf072eb59 Replace abort with flint_abort.
This will allow us to not loose the julia session on error.
See also https://github.com/wbhart/flint2/pull/243
2017-02-28 16:52:57 +01:00

39 lines
1,001 B
C

/*
Copyright (C) 2016 Pascal Molin
This file is part of Arb.
Arb 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 2.1 of the License, or
(at your option) any later version. See <http://www.gnu.org/licenses/>.
*/
#include "dlog.h"
/* for odd prime p, assume b1 = 1 mod p */
ulong
dlog_1modpe_1modp(ulong b1, ulong p, ulong e, ulong inv1p, nmod_t pe)
{
int f;
ulong x, xf, pf, pf1;
pf1 = 1;
pf = p;
x = 0;
for (f = 1; f < e; f++)
{
if (b1 % pf != 1)
{
flint_printf("ERROR dlog_1modpe_1modp: %wu %% %wu != 1 mod %wu\n\n",
b1, pf, pe.n);
flint_abort();
}
xf = (b1 - 1) / pf;
xf = (xf % p) * pf1;
x += xf;
b1 = nmod_mul(b1, nmod_pow_ui(inv1p, xf, pe), pe);
pf1 = pf;
pf *= p;
}
return x;
}