[Python-Dev] Re: native code compiler? (or, OCaml vs. Python)

[Neal Norwitz]

On Mon, Feb 03, 2003 at 11:17:11AM -0800, Neil Schemenauer wrote:
> Guido van Rossum wrote:
> > I'm in.  Given how low you set your stakes, I don't think you're very
> > confident, so I'd like to call your bluff. :-)
> 
> Any opinion on where to spend effort?  I was thinking of dusting off the
> register VM code (aka rattlesnake).  OTOH, perhaps the non-local
> namespace optimizations would give more bang for the buck.

As Guido mentioned, inline builtins.  I have a real simple patch
which does this.  ie, LOAD_GLOBAL(name) -> LOAD_CONST(builtin_function).
However, there is a problem with the patch: the resulting code
can't be marshalled properly.  I haven't tried to fix that yet.

Right now JUMP_IF_(TRUE, FALSE) keep their computed value on the
stack.  They are always followed by POP_TOP.  If the JUMP_IF_* removed
the value, it would be one less trip through eval_frame loop (no
POP_TOP).  I've got a patch for this which fixes 5 of the 8 cases
where JUMP_IF_* are generated.  The problem with the remaining 3 cases
is that a jump to a jump occurs.  By removing the jump to a jump, that
should also help performance.

I have a crazy idea that removing the switch and making our own
jump table in the eval_frame loop could improve performance.
But I've never tried this because it's a lot of work.  And it
could hurt, not help performance.

I can mail or post the partial patches if anyone is interested.

Neal