likely.h 690 B

123456789101112131415161718
  1. // Copyright (c) 2011-present, Facebook, Inc. All rights reserved.
  2. // This source code is licensed under both the GPLv2 (found in the
  3. // COPYING file in the root directory) and Apache 2.0 License
  4. // (found in the LICENSE.Apache file in the root directory).
  5. //
  6. // Copyright (c) 2011 The LevelDB Authors. All rights reserved.
  7. // Use of this source code is governed by a BSD-style license that can be
  8. // found in the LICENSE file. See the AUTHORS file for names of contributors.
  9. #pragma once
  10. #if defined(__GNUC__) && __GNUC__ >= 4
  11. #define LIKELY(x) (__builtin_expect((x), 1))
  12. #define UNLIKELY(x) (__builtin_expect((x), 0))
  13. #else
  14. #define LIKELY(x) (x)
  15. #define UNLIKELY(x) (x)
  16. #endif