> Indeed, see http://bugs.python.org/issue11244
Yes, I've noticed that too. However, if I'm not missing something, your patches do not address folding of -0. Btw, there's an alternative approach to allow "recursive" constant folding. Instead of keeping a stack of last constants, you can keep a pointer to the start of the last (LOAD_CONSTs + NOPs) run and the number of LOAD_CONSTs in that run (called lastlc in the current version). When you want Nth constant from the end, you start from that pointer and skip lastlc-N constants. You also make a function to get next constant from that point. This approach has worse time complexity for searching in a long run of LOAD_CONSTs, however, there are upsides: - very long runs of constants are rare in real code - it uses less memory and doesn't have arbitrary limits on the size of the run - it's book-keeping overhead is smaller, so when you don't have long runs of constants (common case, I believe), it should be faster - I think it's simpler to implement (There's also an optimization -- if (current_position - start_of_run) / 3 == lastlc there are no NOPs in the run and you can get constants by simple indexing). Eugene _______________________________________________ Python-Dev mailing list Python-Dev@python.org http://mail.python.org/mailman/listinfo/python-dev Unsubscribe: http://mail.python.org/mailman/options/python-dev/archive%40mail-archive.com
