| // Copyright 2012 Cloudera 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. |
| |
| |
| #ifndef IMPALA_COMMON_COMPILER_UTIL_H |
| #define IMPALA_COMMON_COMPILER_UTIL_H |
| |
| // Compiler hint that this branch is likely or unlikely to |
| // be taken. Take from the "What all programmers should know |
| // about memory" paper. |
| // example: if (LIKELY(size > 0)) { ... } |
| // example: if (UNLIKELY(!status.ok())) { ... } |
| #ifdef LIKELY |
| #undef LIKELY |
| #endif |
| |
| #ifdef UNLIKELY |
| #undef UNLIKELY |
| #endif |
| |
| #define LIKELY(expr) __builtin_expect(!!(expr), 1) |
| #define UNLIKELY(expr) __builtin_expect(!!(expr), 0) |
| |
| #define PREFETCH(addr) __builtin_prefetch(addr) |
| |
| #endif |
| |
