Peephole optimisation

[Jeff Siegal]

In article <420 at chem.ucsd.EDU> tps at chem.ucsd.edu (Tom Stockfisch) writes:
>I don't think three instructions is enough if your RISC machine has
>a lot of parallelization and scheduling is considered.
>[...]Perhaps some
>specialized scheduler pass would be more practical.

I have to agree with this last assessment.  In general, scheduling is
very different from peephole optimization.  A peephole optimizer
usually transforms a code sequence into an equivalent (but shorter)
code sequence, while a scheduler will be concerned with ordering of
instructions.  

In addition, the strategies for selecting the optimal (or at least
better) are quite different from those used in a peephole optimizer.

Jeff Siegal