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/* Copyright (C) 2011-2024 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
<https://www.gnu.org/licenses/>. */
#include <errno.h>
#include <math.h>
#include <math_private.h>
#include <math-svid-compat.h>
#if LIBM_SVID_COMPAT
static double
__attribute__ ((noinline))
sysv_scalb (double x, double fn)
{
double z = __ieee754_scalb (x, fn);
if (__glibc_unlikely (isinf (z)))
{
if (isfinite (x))
return __kernel_standard (x, fn, 32); /* scalb overflow */
else
__set_errno (ERANGE);
}
else if (__builtin_expect (z == 0.0, 0) && z != x)
return __kernel_standard (x, fn, 33); /* scalb underflow */
return z;
}
/* Wrapper scalb */
double
__scalb (double x, double fn)
{
if (__glibc_unlikely (_LIB_VERSION == _SVID_))
return sysv_scalb (x, fn);
else
{
double z = __ieee754_scalb (x, fn);
if (__glibc_unlikely (!isfinite (z) || z == 0.0))
{
if (isnan (z))
{
if (!isnan (x) && !isnan (fn))
__set_errno (EDOM);
}
else if (isinf (z))
{
if (!isinf (x) && !isinf (fn))
__set_errno (ERANGE);
}
else
{
/* z == 0. */
if (x != 0.0 && !isinf (fn))
__set_errno (ERANGE);
}
}
return z;
}
}
weak_alias (__scalb, scalb)
# ifdef NO_LONG_DOUBLE
strong_alias (__scalb, __scalbl)
weak_alias (__scalb, scalbl)
# endif
#endif
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