mirror of
https://sourceware.org/git/glibc.git
synced 2024-11-24 18:23:41 +08:00
59 lines
1.6 KiB
C
59 lines
1.6 KiB
C
/* Copyright (C) 2011-2013 Free Software Foundation, Inc.
|
|
This file is part of the GNU C Library.
|
|
Contributed by Ulrich Drepper <drepper@gmail.com>, 2011.
|
|
|
|
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/>. */
|
|
|
|
#include <fenv.h>
|
|
#include <math.h>
|
|
#include <math_private.h>
|
|
|
|
|
|
static double
|
|
__attribute__ ((noinline))
|
|
invalid_fn (double x, double fn)
|
|
{
|
|
if (__rint (fn) != fn)
|
|
{
|
|
feraiseexcept (FE_INVALID);
|
|
return __nan ("");
|
|
}
|
|
else if (fn > 65000.0)
|
|
return __scalbn (x, 65000);
|
|
else
|
|
return __scalbn (x,-65000);
|
|
}
|
|
|
|
|
|
double
|
|
__ieee754_scalb (double x, double fn)
|
|
{
|
|
if (__builtin_expect (__isnan (x), 0))
|
|
return x * fn;
|
|
if (__builtin_expect (!__finite (fn), 0))
|
|
{
|
|
if (__isnan (fn) || fn > 0.0)
|
|
return x * fn;
|
|
if (x == 0.0)
|
|
return x;
|
|
return x / -fn;
|
|
}
|
|
if (__builtin_expect ((double) (int) fn != fn, 0))
|
|
return invalid_fn (x, fn);
|
|
|
|
return __scalbn (x, (int) fn);
|
|
}
|
|
strong_alias (__ieee754_scalb, __scalb_finite)
|