The invention relates to a multi-thread power gating control design, setting idle components into a sleep mode to reduce power consumption due to current leakage. Based on compiler techniques, the invention arranges predicted-power-gating instructions into every thread of a may-happen-in-parallel region. A predicted-power-on instruction determines whether the corresponding component has been powered on, and powers on the component when it has not been powered on yet. A predicted-power-off instruction determines whether the component is required in the rest of the may-happen-in-parallel region, and powers off the component when it is required later.