glibc/sysdeps/ieee754/flt-32/math_errf.c
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2019-01-01 00:11:28 +00:00

77 lines
1.9 KiB
C

/* Single-precision math error handling.
Copyright (C) 2017-2019 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
<http://www.gnu.org/licenses/>. */
#include "math_config.h"
#if WANT_ERRNO
# include <errno.h>
/* NOINLINE reduces code size. */
NOINLINE static float
with_errnof (float y, int e)
{
errno = e;
return y;
}
#else
# define with_errnof(x, e) (x)
#endif
/* NOINLINE prevents fenv semantics breaking optimizations. */
NOINLINE static float
xflowf (uint32_t sign, float y)
{
y = (sign ? -y : y) * y;
return with_errnof (y, ERANGE);
}
attribute_hidden float
__math_uflowf (uint32_t sign)
{
return xflowf (sign, 0x1p-95f);
}
#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 float
__math_may_uflowf (uint32_t sign)
{
return xflowf (sign, 0x1.4p-75f);
}
#endif
attribute_hidden float
__math_oflowf (uint32_t sign)
{
return xflowf (sign, 0x1p97f);
}
attribute_hidden float
__math_divzerof (uint32_t sign)
{
float y = 0;
return with_errnof ((sign ? -1 : 1) / y, ERANGE);
}
attribute_hidden float
__math_invalidf (float x)
{
float y = (x - x) / (x - x);
return isnan (x) ? y : with_errnof (y, EDOM);
}