[Python-ideas] Disable all peephole optimizations

[Ned Batchelder]

On 5/22/14 4:25 AM, Nick Coghlan wrote:
>
>
> On 22 May 2014 12:00, "Ned Batchelder" <ned at nedbatchelder.com 
> <mailto:ned at nedbatchelder.com>> wrote:
> >
> > I'm surprised at the amount of invention and mystery code people 
> will propose to avoid having an off-switch for the code we already have.
>
> It's not the off switch per se, it's the documentation and testing 
> consequences. Better to figure out a way to let the code generator and 
> analysis tools collaborate more effectively than to complicate the 
> execution model further.
>

The problem with "letting them collaborate more effectively" is that we 
don't know how to do that.  If we can come up with a way to do it, it 
will involve much more complex code than I am proposing.

As far as documentation, we have three possibilities for optimization 
level now.  This will add a fourth.  I don't see that as a burden.

On the testing front, if I were the developer of an optimizer, I would 
welcome a switch to disable it, as a way to test that optimizations 
don't change semantics.  I understand that this is a different mode of 
execution.  I guess we have different opinions about the tradeoff of 
risk and benefit of that new mode.

> Cheers,
> Nick.
>
>

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