reactos/lib/msvcrt/math/floor.c

   1 /* Math functions for i387.
   2    Copyright (C) 1995, 1996, 1997 Free Software Foundation, Inc.
   3    This file is part of the GNU C Library.
   4    Contributed by John C. Bowman <bowman@ipp-garching.mpg.de>, 1995.
   5
   6    The GNU C Library is free software; you can redistribute it and/or
   7    modify it under the terms of the GNU Library General Public License as
   8    published by the Free Software Foundation; either version 2 of the
   9    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    Library General Public License for more details.
  15
  16    You should have received a copy of the GNU Library General Public
  17    License along with the GNU C Library; see the file COPYING.LIB.  If not,
  18    write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
  19    Boston, MA 02111-1307, USA.  */
  20
  21 #include <msvcrt/math.h>
  22
  23 double floor (double __x);
  24
  25 double floor (double __x)
  26 {
  27   register double __value;
  28   __volatile unsigned short int __cw, __cwtmp;
  29
  30   __asm __volatile ("fnstcw %0" : "=m" (__cw));
  31   __cwtmp = (__cw & 0xf3ff) | 0x0400; /* rounding down */
  32   __asm __volatile ("fldcw %0" : : "m" (__cwtmp));
  33   __asm __volatile ("frndint" : "=t" (__value) : "0" (__x));
  34   __asm __volatile ("fldcw %0" : : "m" (__cw));
  35
  36   return __value;
  37 }