[Python-Dev] Why is Bytecode the way it is?

[Paul Prescod]

Raymond Hettinger wrote:

>...
> The eval loop is already pretty tight.

Compared to what? Total runtime of Python programs? Psycho? Java 
implementations?

I suppose the statement is based on the observation that compiling away 
the eval loop by using Pyrex or Python2C results in very little speed gain.

> As for tweaking opcodes, the biggest remaining wins are in LOAD_ATTR and
> CALL_FUNCTION.  They've been specialized enough that making further
> improvements is non-trivial.

I'm really not even proposing a change to Python as much as trying to 
understand why it is the way it is. I can see how a stack is helpful for 
evaluating deeply nested expressions (although temporary variables seems 
another good valid approach). I just don't see the payoff for shuffling 
variables from locals onto the stack and back into the locals table.

  Paul Prescod