| // Licensed to the Apache Software Foundation (ASF) under one |
| // or more contributor license agreements. See the NOTICE file |
| // distributed with this work for additional information |
| // regarding copyright ownership. The ASF licenses this file |
| // to you 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 PARQUET_UTIL_COMPILER_UTIL_H |
| #define PARQUET_UTIL_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) |
| |
| // macros to disable padding |
| // these macros are portable across different compilers and platforms |
| //[https://github.com/google/flatbuffers/blob/master/include/flatbuffers/flatbuffers.h#L1355] |
| #if defined(_MSC_VER) |
| #define MANUALLY_ALIGNED_STRUCT(alignment) \ |
| __pragma(pack(1)); \ |
| struct __declspec(align(alignment)) |
| #define STRUCT_END(name, size) \ |
| __pragma(pack()); \ |
| static_assert(sizeof(name) == size, "compiler breaks packing rules") |
| #elif defined(__GNUC__) || defined(__clang__) |
| #define MANUALLY_ALIGNED_STRUCT(alignment) \ |
| _Pragma("pack(1)") struct __attribute__((aligned(alignment))) |
| #define STRUCT_END(name, size) \ |
| _Pragma("pack()") static_assert(sizeof(name) == size, "compiler breaks packing rules") |
| #else |
| #error Unknown compiler, please define structure alignment macros |
| #endif |
| |
| #endif // PARQUET_UTIL_COMPILER_UTIL_H |