glibc/math/w_scalb_template.c

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/* Wrapper to set errno for scalb.
Copyright (C) 2020-2024 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
<http://www.gnu.org/licenses/>. */
/* Only build wrappers from the templates for the types that define the macro
below. This macro is set in math-type-macros-<type>.h in sysdeps/generic
for each floating-point type. */
#if __USE_WRAPPER_TEMPLATE
#include <errno.h>
#include <math.h>
#include <math_private.h>
/* Wrapper scalb */
FLOAT M_DECL_FUNC (__scalb) (FLOAT x, FLOAT fn)
{
FLOAT z = M_SUF (__ieee754_scalb) (x, fn);
if (__glibc_unlikely (!isfinite (z) || z == M_LIT (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 != M_LIT (0.0) && !isinf (fn))
__set_errno (ERANGE);
}
}
return z;
}
/* Don't provide _FloatN aliases for scalb which is a deprecated interface,
was obsolescent in POSIX.1-2001, removed in POSIX.1-2008, never made to
C standard. */
#undef libm_alias_float_other_r
#define libm_alias_float_other_r(from, to, r)
#undef libm_alias_double_other_r
#define libm_alias_double_other_r(from, to, r)
#undef libm_alias_ldouble_other_r
#define libm_alias_ldouble_other_r(from, to, r)
#undef libm_alias_float128_other_r
#define libm_alias_float128_other_r(from, to, r)
declare_mgen_alias (__scalb, scalb);
#endif /* __USE_WRAPPER_TEMPLATE. */