93 lines
2.3 KiB
C
93 lines
2.3 KiB
C
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/* Double-precision math error handling.
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Copyright (C) 2018-2022 Free Software Foundation, Inc.
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This file is part of the GNU C Library.
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The GNU C Library is free software; you can redistribute it and/or
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modify it under the terms of the GNU Lesser General Public
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License as published by the Free Software Foundation; either
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version 2.1 of the License, or (at your option) any later version.
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The GNU C Library is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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Lesser General Public License for more details.
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You should have received a copy of the GNU Lesser General Public
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License along with the GNU C Library; if not, see
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<https://www.gnu.org/licenses/>. */
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#include <math-barriers.h>
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#include "math_config.h"
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#if WANT_ERRNO
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#include <errno.h>
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/* NOINLINE reduces code size and avoids making math functions non-leaf
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when the error handling is inlined. */
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NOINLINE static double
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with_errno (double y, int e)
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{
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errno = e;
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return y;
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}
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#else
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#define with_errno(x, e) (x)
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#endif
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/* NOINLINE reduces code size. */
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NOINLINE static double
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xflow (uint32_t sign, double y)
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{
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y = math_opt_barrier (sign ? -y : y) * y;
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return with_errno (y, ERANGE);
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}
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attribute_hidden double
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__math_uflow (uint32_t sign)
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{
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return xflow (sign, 0x1p-767);
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}
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#if WANT_ERRNO_UFLOW
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/* Underflows to zero in some non-nearest rounding mode, setting errno
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is valid even if the result is non-zero, but in the subnormal range. */
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attribute_hidden double
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__math_may_uflow (uint32_t sign)
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{
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return xflow (sign, 0x1.8p-538);
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}
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#endif
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attribute_hidden double
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__math_oflow (uint32_t sign)
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{
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return xflow (sign, 0x1p769);
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}
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attribute_hidden double
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__math_divzero (uint32_t sign)
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{
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double y = math_opt_barrier (sign ? -1.0 : 1.0) / 0.0;
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return with_errno (y, ERANGE);
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}
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attribute_hidden double
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__math_invalid (double x)
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{
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double y = (x - x) / (x - x);
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return isnan (x) ? y : with_errno (y, EDOM);
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}
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/* Check result and set errno if necessary. */
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attribute_hidden double
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__math_check_uflow (double y)
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{
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return y == 0.0 ? with_errno (y, ERANGE) : y;
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}
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attribute_hidden double
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__math_check_oflow (double y)
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{
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return isinf (y) ? with_errno (y, ERANGE) : y;
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}
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