cutils/compiler.h

   1 /*
   2  * Copyright (C) 2009 The Android Open Source Project
   3  *
   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
   7  *
   8  *      http://www.apache.org/licenses/LICENSE-2.0
   9  *
  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.
  15  */
  16
  17 #ifndef ANDROID_CUTILS_COMPILER_H
  18 #define ANDROID_CUTILS_COMPILER_H
  19
  20 /*
  21  * helps the compiler's optimizer predicting branches
  22  */
  23
  24 #ifdef __cplusplus
  25 #   define CC_LIKELY( exp )    (__builtin_expect( !!(exp), true ))
  26 #   define CC_UNLIKELY( exp )  (__builtin_expect( !!(exp), false ))
  27 #else
  28 #   define CC_LIKELY( exp )    (__builtin_expect( !!(exp), 1 ))
  29 #   define CC_UNLIKELY( exp )  (__builtin_expect( !!(exp), 0 ))
  30 #endif
  31
  32 /**
  33  * exports marked symbols
  34  *
  35  * if used on a C++ class declaration, this macro must be inserted
  36  * after the "class" keyword. For instance:
  37  *
  38  * template <typename TYPE>
  39  * class ANDROID_API Singleton { }
  40  */
  41
  42 #define ANDROID_API __attribute__((visibility("default")))
  43
  44 #endif // ANDROID_CUTILS_COMPILER_H