arb/arf/get_mag.c
2015-04-19 05:42:29 +02:00

74 lines
1.9 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) 2014 Fredrik Johansson
******************************************************************************/
#include "arf.h"
void
arf_get_mag(mag_t y, const arf_t x)
{
if (arf_is_zero(x))
{
mag_zero(y);
}
else if (arf_is_special(x))
{
mag_inf(y);
}
else
{
mp_limb_t t, u;
ARF_GET_TOP_LIMB(t, x);
t = (t >> (FLINT_BITS - MAG_BITS)) + LIMB_ONE;
u = t >> MAG_BITS;
t = (t >> u) + u;
_fmpz_add_fast(MAG_EXPREF(y), ARF_EXPREF(x), u);
MAG_MAN(y) = t;
}
}
void
arf_get_mag_lower(mag_t y, const arf_t x)
{
if (arf_is_zero(x))
{
mag_zero(y);
}
else if (arf_is_special(x))
{
if (arf_is_nan(x))
mag_zero(y);
else
mag_inf(y);
}
else
{
mp_limb_t t;
ARF_GET_TOP_LIMB(t, x);
MAG_MAN(y) = t >> (FLINT_BITS - MAG_BITS);
_fmpz_set_fast(MAG_EXPREF(y), ARF_EXPREF(x));
}
}