This intrinsic inserts a NOP instruction or an equivalent code sequence into the instruction stream generated by the compiler. One NOP instruction is generated for each __nop intrinsic in the source.
The compiler does not optimize‑away the NOP instructions, except for normal unreachable‑code elimination. The __nop intrinsic also acts as a barrier for instruction scheduling in the compiler. That is, instructions are not moved from one side of the NOP to the other as a result of optimization.
Note
You can use the __schedule_barrier intrinsic to insert a scheduling barrier without generating a NOP instruction.