5. Exercise 1.7: Performance (12 points). ISAs can have a profound impact on the performance of an application. A program compiled to an ARM processor ends up executing a billion (10) instructions in 1.8s when run to completion. The program when compiled to a MIPS processor that implements the same microarchitecture as the ARM processor executes 1.2 billion instructions in 2.4s when run to completion. (a) (4 points) Find the average CPI in each case given that the processors run at a clock frequency of 1 GHz. (b) (4 points) Assume that we improved the clock rate of one of the processors. If the execution times on the two processors are the same, which processor has a faster clock and by how much faster is it? (Provide a ratio of the clock frequencies of the two processors - e.g., 1.5X faster) () (4 points) The program is next compiled to an x86 processor on which the dynamic instruction count is observed to be just 0.6 billion instructions, resulting in an average CPI of 1.1. However, the x86 pro- cessor has a cycle time of 3 ns. Is the x86 processor faster than the 1 GHz MIPS and ARM processors? If it is in fact faster, what is the speedup