Excepts.cpp

/* Copyright (c) 2016 Baidu, Inc. All Rights Reserve.

Licensed under the Apache License, Version 2.0 (the "License");
you may not use this file except in compliance with the License.
You may obtain a copy of the License at

    http://www.apache.org/licenses/LICENSE-2.0

Unless required by applicable law or agreed to in writing, software
distributed under the License is distributed on an "AS IS" BASIS,
WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
See the License for the specific language governing permissions and
limitations under the License. */

#include "Excepts.h"

#if defined(__APPLE__) || defined(__OSX__)

#include <fenv.h>

int fegetexcept(void) {
  static fenv_t fenv;
  return fegetenv(&fenv) ? -1 : (fenv.__control & FE_ALL_EXCEPT);
}

int feenableexcept(unsigned int excepts) {
  static fenv_t fenv;
  unsigned int new_excepts = excepts & FE_ALL_EXCEPT, old_excepts;

  if (fegetenv(&fenv)) return -1;
  old_excepts = fenv.__control & FE_ALL_EXCEPT;

  // unmask
  fenv.__control &= ~new_excepts;
  fenv.__mxcsr &= ~(new_excepts << 7);

  return (fesetenv(&fenv) ? -1 : old_excepts);
}

int fedisableexcept(unsigned int excepts) {
  static fenv_t fenv;
  unsigned int new_excepts = excepts & FE_ALL_EXCEPT, old_excepts;

  if (fegetenv(&fenv)) return -1;
  old_excepts = fenv.__control & FE_ALL_EXCEPT;

  // mask
  fenv.__control |= new_excepts;
  fenv.__mxcsr |= new_excepts << 7;

  return (fesetenv(&fenv) ? -1 : old_excepts);
}

#endif