[Python-Dev] AST optimizer implemented in Python

[Ned Batchelder]

On 8/11/2012 2:30 PM, Victor Stinner wrote:
> Hi,
>
> I started to implement an AST optimizer in Python. It's easy to create
> a new AST tree, so I'm surprised that I didn't find any existing
> project.
>
> https://bitbucket.org/haypo/misc/src/tip/python/ast_optimizer.py
>
> To test its peephole optimizations (by checking manually its final
> bytecode), I wrote a patch for Python to disable Python internal
> peephole optimizer (on bytecode):
> https://bitbucket.org/haypo/misc/src/tip/python/compile_disable_peephole.patch
>
>
I would very much like to see the ability to disable all optimizers.  As 
work continues on the various forms of optimization, please remember 
that sometimes programs are executed to reason about them, for example, 
when measuring test coverage, or when debugging. Just as gcc has a -O0 
option to disable all code optimizations so that you can more easily 
debug programs, it would be fabulous for CPython to have an option to 
disable all code optimizations.  This would include the existing 
peephole optimizer as well as any new optimizers such as Victor's AST 
optimizer.

Full disclosure: I previously raised this possibility in ticket, and it 
was not as popular as I had hoped: http://bugs.python.org/issue2506

--Ned.