Problem
Assume a program requires the execution of 50 X 106 FP instructions, 110 X 106 INT instructions, 80 X 106 US instructions, and 16 X 106 branch instructions. The CPI for each type of instruction is 1, l, 4, and 2, respectively. Assume that the processor has a 2 GHz clock rate.
1. By how much must we improve the CPI of FP instructions if we want the program to run two times faster?
2. By how much must we improve the CPI of US instructions if we want the program to run two times faster?
3. By how much is the execution time of the program improved if the CPI of INT and F P instructions is reduced by 40% and the CPI of US and Branch is reduced by 30%?