llvm-project/libc/AOR_v20.02/math/math_err.c

82 lines
1.6 KiB
C

/*
* Double-precision math error handling.
*
* Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
* See https://llvm.org/LICENSE.txt for license information.
* SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
*/
#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 = eval_as_double (opt_barrier_double (sign ? -y : y) * y);
return with_errno (y, ERANGE);
}
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. */
HIDDEN double
__math_may_uflow (uint32_t sign)
{
return xflow (sign, 0x1.8p-538);
}
#endif
HIDDEN double
__math_oflow (uint32_t sign)
{
return xflow (sign, 0x1p769);
}
HIDDEN double
__math_divzero (uint32_t sign)
{
double y = opt_barrier_double (sign ? -1.0 : 1.0) / 0.0;
return with_errno (y, ERANGE);
}
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. */
HIDDEN double
__math_check_uflow (double y)
{
return y == 0.0 ? with_errno (y, ERANGE) : y;
}
HIDDEN double
__math_check_oflow (double y)
{
return isinf (y) ? with_errno (y, ERANGE) : y;
}