feenablxcpt.c

来自「linux下的C语言库源码有一百多M解压后很不错」· C语言 代码 · 共 38 行

/* Enable floating-point exceptions.
   Copyright (C) 2000 Free Software Foundation, Inc.
   This file is part of the GNU C Library.
   Contributed by Jes Sorensen <[e-mail]>, 2000.

   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.h>

int
feenableexcept (int excepts)
{
  fenv_t old_fpsr;
  fenv_t new_fpsr;

  /* Get the current fpsr.  */
  __asm__ __volatile__ ("mov.m %0=ar.fpsr" : "=r" (old_fpsr));

  new_fpsr = old_fpsr & ~((fenv_t) excepts & FE_ALL_EXCEPT);

  __asm__ __volatile__ ("mov.m ar.fpsr=%0" :: "r" (new_fpsr) : "memory");

  return (old_fpsr ^ FE_ALL_EXCEPT) & FE_ALL_EXCEPT;
}