Assume the breakdown of dynamic instructions into various instruction categories is as follows: R-type: 40% BEQ: 15% JMP: 10% LW: 25% SW: 10% Assume the following branch predictor accuracies: Always-taken: 45% 2-Bit: 85%

a. What is the extra CPI due to mis-predicted branches with the 2-bit predictor? Assume the branch outcomes are determined in the EX stage, that there are no data hazards, and that no delay slots are used.

b. With the 2-bit predictor, what speedup would be achieved if we could rewrite the code to replace half the branch instructions with ALU instructions? Assume that correctly and incorrectly predicted instructions have the same chance of being replaced.