diff options
Diffstat (limited to 'libstdc++-v3/src/c++11/shared_ptr.cc')
| -rw-r--r-- | libstdc++-v3/src/c++11/shared_ptr.cc | 8 |
1 files changed, 6 insertions, 2 deletions
diff --git a/libstdc++-v3/src/c++11/shared_ptr.cc b/libstdc++-v3/src/c++11/shared_ptr.cc index 74e879e5828..ae47ca03301 100644 --- a/libstdc++-v3/src/c++11/shared_ptr.cc +++ b/libstdc++-v3/src/c++11/shared_ptr.cc @@ -34,8 +34,12 @@ namespace __gnu_internal _GLIBCXX_VISIBILITY(hidden) __gnu_cxx::__mutex& get_mutex(unsigned char i) { - // increase alignment to put each lock on a separate cache line - struct alignas(64) M : __gnu_cxx::__mutex { }; +#ifdef _GLIBCXX_CAN_ALIGNAS_DESTRUCTIVE_SIZE + // Increase alignment to put each lock on a separate cache line. + struct alignas(__GCC_DESTRUCTIVE_SIZE) M : __gnu_cxx::__mutex { }; +#else + using M = __gnu_cxx::__mutex; +#endif // Use a static buffer, so that the mutexes are not destructed // before potential users (or at all) static __attribute__ ((aligned(__alignof__(M)))) |