Author: Armin Rigo <ar...@tunes.org> Branch: Changeset: r76300:17681166180a Date: 2015-03-10 18:16 +0100 http://bitbucket.org/pypy/pypy/changeset/17681166180a/
Log: Make some more virtualizable-array rules explicit diff --git a/rpython/doc/jit/virtualizable.rst b/rpython/doc/jit/virtualizable.rst --- a/rpython/doc/jit/virtualizable.rst +++ b/rpython/doc/jit/virtualizable.rst @@ -44,8 +44,14 @@ virtualizable arrays that can be very confusing. Those will usually end up with a compile-time error (as opposed to strange behavior). The rules are: +* A virtualizable array must be a fixed-size list. After it is + initialized (e.g. in ``Frame.__init__``) you cannot resize it at all. + You cannot assign a different list to the field, or even pass around the + list. You can only access ``frame.array[index]`` directly. + * Each array access must be with a known positive index that cannot raise - an ``IndexError``. Using ``no = jit.hint(no, promote=True)`` might be useful + an ``IndexError``. + Using ``index = jit.hint(index, promote=True)`` might be useful to get a constant-number access. This is only safe if the index is actually constant or changing rarely within the context of the user's code. _______________________________________________ pypy-commit mailing list pypy-commit@python.org https://mail.python.org/mailman/listinfo/pypy-commit
