mathinline.h

glibc 2.9,最新版的C语言库函数

/* Inline math functions for ia64.
   Copyright (C) 2004, 2007 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, write to the Free
   Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
   02111-1307 USA.  */

#ifndef _MATH_H
# error "Never use <bits/mathinline.h> directly; include <math.h> instead."
#endif

#ifndef __extern_inline
# define __MATH_INLINE __inline
#else
# define __MATH_INLINE __extern_inline
#endif

#if defined __USE_ISOC99 && defined __GNUC__ && __GNUC__ >= 2
/* The gcc, version 2.7 or below, has problems with all this inlining
   code.  So disable it for this version of the compiler.  */
# if __GNUC_PREREQ (2, 8)
/* Test for negative number.  Used in the signbit() macro.  */
__MATH_INLINE int
__NTH (__signbitf (float __x))
{
  __extension__ union { float __f; int __i; } __u = { __f: __x };
  return __u.__i < 0;
}
__MATH_INLINE int
__NTH (__signbit (double __x))
{
  __extension__ union { double __d; int __i[2]; } __u = { __d: __x };
  return __u.__i[1] < 0;
}
__MATH_INLINE int
__NTH (__signbitl (long double __x))
{
  __extension__ union { long double __l; int __i[3]; } __u = { __l: __x };
  return (__u.__i[2] & 0x8000) != 0;
}
# endif
#endif