Enforce In-order Execution of Input/Output
Ensures that all I/O storage access instructions preceding the call to __eioeio complete in main memory before I/O storage access instructions following the function call can execute.
void __eieio (void);
void __iospace_eieio (void);
This function is useful for managing shared data instructions where the execution order of load/store access is significant. The function can provide the necessary functionality for controlling I/O stores without the cost to performance that can occur with other synchronization instructions.