isync
Instruction Synchronize
Ensures that all instructions preceding the isync instruction have completed before it completes, and that no subsequent instructions are initiated until after the isync instruction completes.
Details
Executing an isync instruction ensures that all instructions preceding the isync instruction have completed before the isync instruction completes, and that no subsequent instructions are initiated until after the isync instruction completes. It also ensures that all instruction cache block invalidations caused by icbi instructions preceding the isync instruction have been performed with respect to the processor executing the isync instruction, and then causes any prefetched instructions to be discarded.
Pseudocode Operation
ContextSynchronize()Programming Note
Except as described in the preceding sentence, the isync instruction may complete before storage accesses associated with instructions preceding the isync instruction have been performed.