1Intelligent wrong path issue: a means of improving performance By

Speculation of instructions is crucial for modern superscalars Branch predictors provide accuracies of up to 96 % and are key to effective speculation However we cannot rely solely on prediction because the latency of misprediction has a negative impact on performance To solve this problem, computer architects came up with the idea of wrong path issue 3To issue or not to issue? Wrong path issue reduces the misprediction penalty On the other hand, useless wrong path instructions waste processor resources and must invariably be flushed from the pipeline – Have to have enough resources to issue and execute 2 paths knowing that one of them will be invalidated To find a better solution, we look at the behavior of branch instructions: 4Branch behavior Program trace- branch instruction