question archive The importance of having a good branch predictor depends on how often conditional branches are executed
The importance of having a good branch predictor depends on how often conditional branches are executed
Subject:Computer SciencePrice: Bought3
The importance of having a good branch predictor depends on how often
conditional branches are executed. Together with branch predictor accuracy, this will determine how much time is spent stalling due to mispredicted branches. In this exercise, assume that the breakdown of dynamic instructions into various instruction categories is as follows:
R-Type BEQ JMP LW SW
40% 25% 5% 25% 5%
Also, assume the following branch predictor accuracies:
Always - Taken Always-Not-Taken 2-Bit
40% 60% 85%
1.5, With the 2-bit predictor, what speedup would be achieved if we could convert half of the branch instructions in a way that replaced each branch instruction with two ALU instructions? Assume that correctly and incorrectly predicted instructions have the same chance of being replaced.
