Computer Architecture, 5th Edition

3.9 Advanced Techniques for Instruction Delivery and Speculation

In a high-performance pipeline, especially one with multiple issues, predicting branches well is not enough; we actually have to be able to deliver a high-bandwidth instruction stream. In recent multiple-issue processors, this has meant delivering 4 to 8 instructions every clock cycle. We look at methods for increasing instruction delivery bandwidth first. We then turn to a set of key issues in implementing advanced speculation techniques, including the use of register renaming versus reorder buffers, the aggressiveness of speculation, and a technique called value prediction, which attempts to predict the result of a computation and which could further enhance ILP.

Increasing ...