logb.c

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/* Math functions for i387.
   Copyright (C) 1995, 1996, 1997 Free Software Foundation, Inc.
   This file is part of the GNU C Library.
   Contributed by John C. Bowman <bowman@ipp-garching.mpg.de>, 1995.
 
   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., 51 Franklin Street, Fifth Floor,
   Boston, MA 02110-1301, USA.
*/
 
#include <precomp.h>
 
double _logb (double __x)
{
  register double __val;
#ifdef __GNUC__
  register double __junk;
  __asm __volatile__
    ("fxtract\n\t"
     : "=t" (__junk), "=u" (__val) : "0" (__x));
#else
#pragma message ("REVIEW ME")
  __asm fld [__x];
  __asm fxtract;
  __asm fstp st(0);
  __asm fstp [__val];
#endif /*__GNUC__*/
  return __val;
}