/* * Copyright 2016 Facebook, Inc. * * 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. */ /** * Compiler hints to indicate the fast path of an "if" branch: whether * the if condition is likely to be true or false. * * @author Tudor Bosman (tudorb@fb.com) */ #pragma once #undef LIKELY #undef UNLIKELY #if defined(__GNUC__) && __GNUC__ >= 4 #define LIKELY(x) (__builtin_expect((x), 1)) #define UNLIKELY(x) (__builtin_expect((x), 0)) #else #define LIKELY(x) (x) #define UNLIKELY(x) (x) #endif