Cleanup sync_file_range implementation
[glibc.git] / math / e_scalb.c
blobf3dac6f45d4affa5a21aa4bdb22098801dec5306
1 /* Copyright (C) 2011-2015 Free Software Foundation, Inc.
2 This file is part of the GNU C Library.
3 Contributed by Ulrich Drepper <drepper@gmail.com>, 2011.
5 The GNU C Library is free software; you can redistribute it and/or
6 modify it under the terms of the GNU Lesser General Public
7 License as published by the Free Software Foundation; either
8 version 2.1 of the License, or (at your option) any later version.
10 The GNU C Library is distributed in the hope that it will be useful,
11 but WITHOUT ANY WARRANTY; without even the implied warranty of
12 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
13 Lesser General Public License for more details.
15 You should have received a copy of the GNU Lesser General Public
16 License along with the GNU C Library; if not, see
17 <http://www.gnu.org/licenses/>. */
19 #include <fenv.h>
20 #include <math.h>
21 #include <math_private.h>
24 static double
25 __attribute__ ((noinline))
26 invalid_fn (double x, double fn)
28 if (__rint (fn) != fn)
30 __feraiseexcept (FE_INVALID);
31 return __nan ("");
33 else if (fn > 65000.0)
34 return __scalbn (x, 65000);
35 else
36 return __scalbn (x,-65000);
40 double
41 __ieee754_scalb (double x, double fn)
43 if (__glibc_unlikely (isnan (x)))
44 return x * fn;
45 if (__glibc_unlikely (!isfinite (fn)))
47 if (isnan (fn) || fn > 0.0)
48 return x * fn;
49 if (x == 0.0)
50 return x;
51 return x / -fn;
53 if (__glibc_unlikely (fabs (fn) >= 0x1p31 || (double) (int) fn != fn))
54 return invalid_fn (x, fn);
56 return __scalbn (x, (int) fn);
58 strong_alias (__ieee754_scalb, __scalb_finite)