| 1 | /* |
| 2 | * Copyright (c) Meta Platforms, Inc. and affiliates. |
| 3 | * All rights reserved. |
| 4 | * |
| 5 | * This source code is licensed under both the BSD-style license (found in the |
| 6 | * LICENSE file in the root directory of this source tree) and the GPLv2 (found |
| 7 | * in the COPYING file in the root directory of this source tree). |
| 8 | */ |
| 9 | |
| 10 | /** |
| 11 | * Compiler hints to indicate the fast path of an "if" branch: whether |
| 12 | * the if condition is likely to be true or false. |
| 13 | * |
| 14 | * @author Tudor Bosman (tudorb@fb.com) |
| 15 | */ |
| 16 | |
| 17 | #pragma once |
| 18 | |
| 19 | #undef LIKELY |
| 20 | #undef UNLIKELY |
| 21 | |
| 22 | #if defined(__GNUC__) && __GNUC__ >= 4 |
| 23 | #define LIKELY(x) (__builtin_expect((x), 1)) |
| 24 | #define UNLIKELY(x) (__builtin_expect((x), 0)) |
| 25 | #else |
| 26 | #define LIKELY(x) (x) |
| 27 | #define UNLIKELY(x) (x) |
| 28 | #endif |