YIELD is a hint instruction. Software with a multithreading capability can use a
YIELD instruction to indicate to the PE that it is performing a task, for example a spin-lock, that could be swapped out to improve overall system performance. The PE can use this hint to suspend and resume multiple software threads if it supports the capability.
For more information about the recommended use of this instruction, see The YIELD instruction in the ARMv8-A Architecture Reference Manual.