On 7/22/20 6:42 AM, Inada Naoki wrote:
On Wed, Jul 22, 2020 at 6:12 PM Antoine Pitrou <solipsis@pitrou.net> wrote:
> >
> > But if we merge two equal code blocks, we can not produce precise line
> > numbers, can we?
> > Is this inconsistent microoptimization that real optimization harder?
> > This optimization must be prohibited in future Python?
> All attempts to improve Python performance by compile-time
> bytecode optimizations have more or less failed (the latter was
> Victor's, AFAIR).  Is there still interest in pursuing that avenue?
> Regards
> Antoine.

I don't think all attempts are failed.  Note that current CPython includes
some optimization already. If they are all failed, we must remove them
 to make compiler simple.

And I think there are some potential optimization if we can limit some
debugging/introspecting features, like some C variables are "optimzed away" in gdb when
we use -O option.

We seem to like following the C model when it comes to implementing optimizations, and then skip the part where C developers can disable all optimizations when reasoning about code is more important than speed.  I am fine with any optimizations at all, as long as there is a simple and supported way to ask that they be disabled.