2 * Copyright 2014 Facebook, Inc.
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at
8 * http://www.apache.org/licenses/LICENSE-2.0
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
18 * Compiler hints to indicate the fast path of an "if" branch: whether
19 * the if condition is likely to be true or false.
21 * @author Tudor Bosman (tudorb@fb.com)
24 #ifndef FOLLY_BASE_LIKELY_H_
25 #define FOLLY_BASE_LIKELY_H_
30 #if defined(__GNUC__) && __GNUC__ >= 4
31 #define LIKELY(x) (__builtin_expect((x), 1))
32 #define UNLIKELY(x) (__builtin_expect((x), 0))
35 #define UNLIKELY(x) (x)
38 #endif /* FOLLY_BASE_LIKELY_H_ */