Sequential Consistency
With multiple pipelines, how do we maintain sequential consistency when instructions are finishing at different times?
- With just two pipelines (FX and FP), we can lengthen the shorter pipeline with statically or dynamically. Dynamic lengthening would be used only when hazards are detected.
- We can force the pipelines to write to a special unit called a Renaming Buffer or Reordering Buffer. It is the job of this unit to maintain sequential consistency. Will look at this in detail in Chapter 7 (superscalar).