Couple uses of "it" here are ambiguous -- are you saying we don't need co_extra after all, or that we can safely insist it's a dict, or...?
On Mon, Jun 20, 2016 at 1:20 PM, Dino Viehland via Python-Dev < python-dev@python.org> wrote: > Mark wrote: > > > Dino and I thought of two potential alternatives, neither of which we > > > have taken the time to implement and benchmark. One is to simply have > > > a hash table of memory addresses to JIT data that is kept on the JIT > > > side of things. Obviously it would be nice to avoid the overhead of a > > > hash table lookup on every function call. This also doesn't help > > > minimize memory when the code object gets GC'ed. > > > > Hash lookups aren't that slow. If you combine it with the custom flags > > suggested by MRAB, then you would only suffer the lookup penalty when > > actually entering the special interpreter. > > You can use a weakref callback to ensure things get GC'd properly. > > > > Also, if there is a special extra field on code-object, then everyone > will want > > to use it. How do you handle clashes? > > This is exactly what I've started prototyping and have mostly coded up, > I've > just been getting randomized and haven't gotten back to it yet. > > It may have some impact in the short-term but my expectation is that as the > JIT gets better that this will become less and less important. Currently > we're > just JITing one method at a time and have no inlining support. But once we > can start putting guards in place and inlining across multiple function > calls > we will start reducing the transitions from JIT -> Function Call -> JIT > and get > rid of those hash table lookups entirely. And if we can't succeed at > inlining then > I suspect the JIT won't end up offering the performance we'd hope for. > > > _______________________________________________ > Python-Dev mailing list > Python-Dev@python.org > https://mail.python.org/mailman/listinfo/python-dev > Unsubscribe: > https://mail.python.org/mailman/options/python-dev/guido%40python.org > -- --Guido van Rossum (python.org/~guido)
_______________________________________________ Python-Dev mailing list Python-Dev@python.org https://mail.python.org/mailman/listinfo/python-dev Unsubscribe: https://mail.python.org/mailman/options/python-dev/archive%40mail-archive.com
