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86 lines
2.1 KiB
C
86 lines
2.1 KiB
C
/* Copyright (C) 2011-2020 Free Software Foundation, Inc.
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This file is part of the GNU C Library.
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Contributed by Ulrich Drepper <drepper@gmail.com>, 2011.
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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 <errno.h>
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#include <math.h>
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#include <math_private.h>
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#include <math-svid-compat.h>
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#if LIBM_SVID_COMPAT
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static double
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__attribute__ ((noinline))
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sysv_scalb (double x, double fn)
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{
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double z = __ieee754_scalb (x, fn);
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if (__glibc_unlikely (isinf (z)))
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{
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if (isfinite (x))
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return __kernel_standard (x, fn, 32); /* scalb overflow */
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else
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__set_errno (ERANGE);
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}
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else if (__builtin_expect (z == 0.0, 0) && z != x)
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return __kernel_standard (x, fn, 33); /* scalb underflow */
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return z;
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}
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#endif
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/* Wrapper scalb */
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double
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__scalb (double x, double fn)
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{
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#if LIBM_SVID_COMPAT
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if (__glibc_unlikely (_LIB_VERSION == _SVID_))
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return sysv_scalb (x, fn);
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else
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#endif
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{
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double z = __ieee754_scalb (x, fn);
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if (__glibc_unlikely (!isfinite (z) || z == 0.0))
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{
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if (isnan (z))
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{
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if (!isnan (x) && !isnan (fn))
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__set_errno (EDOM);
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}
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else if (isinf (z))
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{
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if (!isinf (x) && !isinf (fn))
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__set_errno (ERANGE);
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}
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else
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{
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/* z == 0. */
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if (x != 0.0 && !isinf (fn))
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__set_errno (ERANGE);
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}
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}
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return z;
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}
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}
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weak_alias (__scalb, scalb)
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#ifdef NO_LONG_DOUBLE
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strong_alias (__scalb, __scalbl)
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weak_alias (__scalb, scalbl)
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#endif
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