fesetround.c

Glibc 2.3.2源代码(解压后有100多M)

/* Set current rounding direction.
   Copyright (C) 2000 Free Software Foundation, Inc.
   This file is part of the GNU C Library.
   Contributed by Denis Joseph Barrow ([e-mail]).

   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.  */

#include <fenv_libc.h>
#include <fpu_control.h>

int
fesetround (int round)
{
  if ((round|FPC_RM_MASK) != FPC_RM_MASK)
    {
      /* ROUND is not a valid rounding mode.  */
      return 1;
    }
  __asm__ volatile ("srnm 0(%0)"
		    :
		    : "a" (round));

  return 0;
}