Atomic Memory Access (Using the GNU Compiler Collection (GCC))

### 7.9 Builtins for Atomic Memory Access ¶

GCC supports two sets of builtins for atomic memory access primitives. The `__atomic` builtins provide the underlying support for the C++11 atomic operations library, and are the currently-recommended interface when the C++11 library functions cannot be used directly. The `__sync` builtins implement the specification from the Intel IA64 pSABI and are supported primarily for use in legacy code.