102 lines
2.9 KiB
C
102 lines
2.9 KiB
C
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/* Double-precision math error handling.
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Copyright (c) 2018 ARM Ltd. All rights reserved.
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SPDX-License-Identifier: BSD-3-Clause
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Redistribution and use in source and binary forms, with or without
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modification, are permitted provided that the following conditions
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are met:
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1. Redistributions of source code must retain the above copyright
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notice, this list of conditions and the following disclaimer.
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2. Redistributions in binary form must reproduce the above copyright
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notice, this list of conditions and the following disclaimer in the
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documentation and/or other materials provided with the distribution.
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3. The name of the company may not be used to endorse or promote
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products derived from this software without specific prior written
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permission.
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THIS SOFTWARE IS PROVIDED BY Arm LTD ``AS IS AND ANY EXPRESS OR IMPLIED
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WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
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MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
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IN NO EVENT SHALL Arm LTD BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
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SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED
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TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
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PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
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LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
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NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
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SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. */
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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 = opt_barrier_double (sign ? -y : y) * y;
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return with_errno (y, ERANGE);
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}
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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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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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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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HIDDEN double
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__math_divzero (uint32_t sign)
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{
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double y = opt_barrier_double (sign ? -1.0 : 1.0) / 0.0;
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return with_errno (y, ERANGE);
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}
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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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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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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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