mirror of
https://github.com/vale981/arb
synced 2025-03-05 09:21:38 -05:00
0244fe0e46
When rounding up, the error bound sometimes came out as 1/2 ulp instead of 1 ulp due to the mantissa rounding up to the next power of two, without a corresponding exponent correction. Fortunately, this should not affect ball arithmetic (which always rounds down).
46 lines
1.4 KiB
C
46 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) 2014 Fredrik Johansson
|
|
|
|
******************************************************************************/
|
|
|
|
#include "fmpr.h"
|
|
|
|
void
|
|
fmpr_ulp(fmpr_t u, const fmpr_t x, long prec)
|
|
{
|
|
if (fmpr_is_special(x))
|
|
{
|
|
fmpr_abs(u, x);
|
|
}
|
|
else
|
|
{
|
|
fmpz_t e;
|
|
fmpz_init(e);
|
|
fmpz_add_ui(e, fmpr_expref(x), fmpz_bits(fmpr_manref(x)));
|
|
fmpz_sub_ui(e, e, prec);
|
|
fmpz_one(fmpr_manref(u));
|
|
fmpz_set(fmpr_expref(u), e);
|
|
fmpz_clear(e);
|
|
}
|
|
}
|
|
|