A processor includes a front end including circuitry to decode a first instruction to set a performance register for an execution unit and a second instruction, and an allocator including circuitry to assign the second instruction to the execution unit to execute the second instruction. The execution unit includes circuitry to select between a normal computation and an accelerated computation based on a mode field of the performance register, perform the selected computation, and select between a normal result associated with the normal computation and an accelerated result associated with the accelerated computation based on the mode field.