[Python-Dev] Suggest reverting today's checkin (recursive constant folding in the peephole optimizer)

[Ned Batchelder]

On 3/12/2011 12:39 AM, Eugene Toder wrote:
>> >  You've got wishful thinking if you think a handful of tests can catch
>> >  errors in code that sophisticated.
> Why limit yourself with a handful of tests? Python is widespread,
> there's*a lot*  of code in Python. Unlike with libraries, any code you
> run tests the optimizer, so just run a lot of code. And, as I've said,
> write a test generator.

As we're thinking about what the optimizer of the future should be, it 
would be great to have a way to turn it off completely.  This would 
allow the tests to run test code both with and without the optimizer, 
and to verify that the two results were the same.  Then we could 
automatically verify that the optimizer isn't changing semantics.

BTW: I also believe it would be very useful to make the 
turn-off-the-optimizer switch available for users so they can run their 
code unoptimized for times when they are more interested in program 
analysis than in execution speed.  See http://bugs.python.org/issue2506 
(closed 3 years ago) that I filed with this request.

--Ned.
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