[pypy-dev] Saving and reloading JIT optimizations

[Carl Friedrich Bolz]

On 08/21/2011 07:49 PM, Zooko O'Whielacronx wrote:
> [following-up to my own post]
>
> On Sun, Aug 21, 2011 at 11:44 AM, Zooko O'Whielacronx<zooko at zooko.com>  wrote:
>>
>> The behavior of a program is a deterministic function of its source
>> code, right? So if the source code (*all* of it -- everything that
>> gets imported and executed at any point during the run of the program)
>> is identical, then the behavior will be identical, and then re-using
>> compiled code from previous runs would always yield a correct result.
>> Am I still on track so far?
>
> Uh-oh, I think I may have already gone off track here in the first
> paragraph. What if you use information from the runtime *inputs* --
> not imported code but inputted data -- to change how you compile the
> code? Then even if *all* of the source code is exactly the same,
> re-using the compiled code from the previous run may generate
> incorrect results. Is that right?

class A(object):
     if time.time() % 2 == 0:
         def f(self):
             return 1
     else:
         def f(self):
             return 2

:-)


Solving the problem of persisting source code is *seriously* hard, and I 
agree with Armin, I'm not going to invest any time in it.


Carl Friedrich