93 lines
2.3 KiB
C
93 lines
2.3 KiB
C
/* Double-precision math error handling.
|
|
Copyright (C) 2018-2022 Free Software Foundation, Inc.
|
|
This file is part of the GNU C Library.
|
|
|
|
The GNU C Library is free software; you can redistribute it and/or
|
|
modify it under the terms of the GNU Lesser General Public
|
|
License as published by the Free Software Foundation; either
|
|
version 2.1 of the License, or (at your option) any later version.
|
|
|
|
The GNU C Library 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
|
|
Lesser General Public License for more details.
|
|
|
|
You should have received a copy of the GNU Lesser General Public
|
|
License along with the GNU C Library; if not, see
|
|
<https://www.gnu.org/licenses/>. */
|
|
|
|
#include <math-barriers.h>
|
|
#include "math_config.h"
|
|
|
|
#if WANT_ERRNO
|
|
#include <errno.h>
|
|
/* NOINLINE reduces code size and avoids making math functions non-leaf
|
|
when the error handling is inlined. */
|
|
NOINLINE static double
|
|
with_errno (double y, int e)
|
|
{
|
|
errno = e;
|
|
return y;
|
|
}
|
|
#else
|
|
#define with_errno(x, e) (x)
|
|
#endif
|
|
|
|
/* NOINLINE reduces code size. */
|
|
NOINLINE static double
|
|
xflow (uint32_t sign, double y)
|
|
{
|
|
y = math_opt_barrier (sign ? -y : y) * y;
|
|
return with_errno (y, ERANGE);
|
|
}
|
|
|
|
attribute_hidden double
|
|
__math_uflow (uint32_t sign)
|
|
{
|
|
return xflow (sign, 0x1p-767);
|
|
}
|
|
|
|
#if WANT_ERRNO_UFLOW
|
|
/* Underflows to zero in some non-nearest rounding mode, setting errno
|
|
is valid even if the result is non-zero, but in the subnormal range. */
|
|
attribute_hidden double
|
|
__math_may_uflow (uint32_t sign)
|
|
{
|
|
return xflow (sign, 0x1.8p-538);
|
|
}
|
|
#endif
|
|
|
|
attribute_hidden double
|
|
__math_oflow (uint32_t sign)
|
|
{
|
|
return xflow (sign, 0x1p769);
|
|
}
|
|
|
|
attribute_hidden double
|
|
__math_divzero (uint32_t sign)
|
|
{
|
|
double y = math_opt_barrier (sign ? -1.0 : 1.0) / 0.0;
|
|
return with_errno (y, ERANGE);
|
|
}
|
|
|
|
attribute_hidden double
|
|
__math_invalid (double x)
|
|
{
|
|
double y = (x - x) / (x - x);
|
|
return isnan (x) ? y : with_errno (y, EDOM);
|
|
}
|
|
|
|
/* Check result and set errno if necessary. */
|
|
|
|
attribute_hidden double
|
|
__math_check_uflow (double y)
|
|
{
|
|
return y == 0.0 ? with_errno (y, ERANGE) : y;
|
|
}
|
|
|
|
attribute_hidden double
|
|
__math_check_oflow (double y)
|
|
{
|
|
return isinf (y) ? with_errno (y, ERANGE) : y;
|
|
}
|