Speculation

This is used everywhere (compiler optimizations, QA predictions, speculatively parallelizing code).

Speculative Evaluation

We could parallelize code that needs to run no matter what, and code that runs in a conditional (as they as there is no dependancy), this is a pre-computation to speed things up.

Value Speculation

This is speculative execution where there is dependancy, but here, we predict the dependant value.

• We can estimate the impact of value speculation by parameterizing:
  • Time it takes to run something
  • Probability that something needs to run again
  • Synchronization overhead