An improvement algorithm to runahead execution

Runahead execution can significantly improve the memory-level parallelism, and processor needn´t be modified a lot. But Runahead execution processor excute more instructions than traditional processor, even triple the number of instructions of the common execution, So it severely increases processors´ power waste. After analyzing, we find there are many useless instructions executed when Runahead processor is in runahead´s execting stage, We present a new algorithm to reduce the useless instructions. The results of the Experimention show that this improvement algorithm mostly can reduce 50% useless instructions in runahead execution processor´s pre-excute stage, and basically don´t affect the performance a lot.