sysdeps/x86_64/fpu/bits/mathinline.h

   1 /* Inline math functions for x86-64.
   2    Copyright (C) 2002, 2003, 2004, 2007 Free Software Foundation, Inc.
   3    This file is part of the GNU C Library.
   4    Contributed by Andreas Jaeger <aj@suse.de>, 2002.
   5
   6    The GNU C Library is free software; you can redistribute it and/or
   7    modify it under the terms of the GNU Lesser General Public
   8    License as published by the Free Software Foundation; either
   9    version 2.1 of the License, or (at your option) any later version.
  10
  11    The GNU C Library is distributed in the hope that it will be useful,
  12    but WITHOUT ANY WARRANTY; without even the implied warranty of
  13    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  14    Lesser General Public License for more details.
  15
  16    You should have received a copy of the GNU Lesser General Public
  17    License along with the GNU C Library; if not, write to the Free
  18    Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
  19    02111-1307 USA.  */
  20
  21 #ifndef _MATH_H
  22 # error "Never use <bits/mathinline.h> directly; include <math.h> instead."
  23 #endif
  24
  25 #ifdef __cplusplus
  26 # define __MATH_INLINE __inline
  27 #else
  28 # define __MATH_INLINE __extern_inline
  29 #endif
  30
  31
  32 #if defined __USE_ISOC99 && defined __GNUC__ && __GNUC__ >= 2
  33
  34 /* Test for negative number.  Used in the signbit() macro.  */
  35 __MATH_INLINE int
  36 __NTH (__signbitf (float __x))
  37 {
  38   __extension__ union { float __f; int __i; } __u = { __f: __x };
  39   return __u.__i < 0;
  40 }
  41 __MATH_INLINE int
  42 __NTH (__signbit (double __x))
  43 {
  44   __extension__ union { double __d; int __i[2]; } __u = { __d: __x };
  45   return __u.__i[1] < 0;
  46 }
  47 __MATH_INLINE int
  48 __NTH (__signbitl (long double __x))
  49 {
  50   __extension__ union { long double __l; int __i[3]; } __u = { __l: __x };
  51   return (__u.__i[2] & 0x8000) != 0;
  52 }
  53 #endif