In the classic 5-stage pipeline, it is proposed to predict branches as always taken instead of always untaken. The branch instruction is decoded in...

 In the classic 5-stage pipeline, it is proposed to predict branches as always taken instead of always untaken. The branch instruction is decoded in ID and its target address is computed in ID. At the end of ID, a conditional branch is always taken and IF is systematically flushed. Then, in the EX stage, the branch condition is evaluated. If the branch is verified taken, then execution continues. However, if the branch is verified untaken, the IF and ID stages are flushed and the instruction at branch_PC + 4 is fetched. (a) What is the fraction f of branches that should be taken so that the design with branch predicted always taken is a good choice over branch predicted always untaken?