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On Mon, 1 Feb 2016 at 09:08 Yury Selivanov <yselivanov.ml@gmail.com> wrote:

On 2016-01-29 11:28 PM, Steven D'Aprano wrote:
\> On Wed, Jan 27, 2016 at 01:25:27PM -0500, Yury Selivanov wrote:
\>> Hi,
\>>
\>>
\>> tl;dr The summary is that I have a patch that improves CPython
\>> performance up to 5-10% on macro benchmarks.� Benchmarks results on
\>> Macbook Pro/Mac OS X, desktop CPU/Linux, server CPU/Linux are available
\>> at \[1\].� There are no slowdowns that I could reproduce consistently.
\> Have you looked at Cesare Di Mauro's wpython? As far as I know, it's now
\> unmaintained, and the project repo on Google Code appears to be dead (I
\> get a 404), but I understand that it was significantly faster than
\> CPython back in the 2.6 days.
\>
\> https://wpython.googlecode.com/files/Beyond%20Bytecode%20-%20A%20Wordcode-based%20Python.pdf
\>
\>

Thanks for bringing this up!

IIRC wpython was about using "fat" bytecodes, i.e. using 64bits per
bytecode instead of 8.� That allows to minimize the number of bytecodes,
thus having some performance increase.� TBH, I don't think it was
"significantly faster".

If I were to do some big refactoring of the ceval loop, I'd probably
consider implementing a register VM.� While register VMs are a bit
faster than stack VMs (up to 20-30%), they would also allow us to apply
more optimizations, and even bolt on a simple JIT compiler.

If you did tackle the register VM approach that would also settle a long-standing question of whether a certain optimization works for Python.

As for bolting on a JIT, the whole point of Pyjion is to see if that's worth it for CPython, so that's already being taken care of (and is actually easier with a stack-based VM since the JIT engine we're using is stack-based itself).