[Python-ideas] Changes to the existing optimization levels

[Antoine Pitrou]

On Fri, 29 Sep 2017 17:33:11 +1000
Nick Coghlan <ncoghlan at gmail.com> wrote:
> 
> That said, we may also want to consider a couple of other options
> related to changing the meaning of *existing* parameters to these
> APIs:
> 
> 1. We have the PyCompilerFlags struct that's currently only used to
> pass around feature flags for the __future__ module. It could gain a
> second bitfield for optimisation options

Not sure about that.  PyCompilerFlags describes options that should be
common to all implementations (since __future__ is part of the language
spec).

> 2. We could reinterpret "optimize" as a bitfield instead of a regular
> integer, special casing the already defined values:
> 
> - all zero: no optimizations
> - sign bit set: negative -> use global settings
> - 0x0001: nodebug+noassert
> - 0x0002: nodebug+noassert+nodocstrings
> - 0x0004: nodebug
> - 0x0008: noassert
> - 0x0010: nodocstrings

Well, this is not really a bitfield, but a bitfield plus some irregular
hardcoded values.  Therefore I don't think it brings much in the way of
discoverability / understandability.

That said, perhaps it makes implementation easier on the C side...

Regards

Antoine.