Christian Heimes <li...@cheimes.de> added the comment: > I haven't read any papers. Having a jump table in itself isn't special > (the compiler does exactly that when compiling the switch() statement). > What's special is that a dedicated indirect jump instruction at the end > of each opcode helps the CPU make a separate prediction for which opcode > follows the other one, which is not possible with a switch statement > where the jump instruction is shared by all opcodes. I believe that's > where most of the speedup comes from. > > If you read the patch it will probably be easy to understand.
You are right. It's easier to understand after I've learned how the opcode_targets table is working. Previously I didn't know that one can store the address of a label in an array. Before I got it I wondered where the pointers were defined. Is this a special GCC feature? I haven't seen it before. > Don't know! Your experiments are welcome. My patch is far simpler to > integrate though (it's small, introduces very few changes and does not > break any existing tests). Yes, your patch is much smaller, less intrusive and easier to understand with a little background in CS. _______________________________________ Python tracker <rep...@bugs.python.org> <http://bugs.python.org/issue4753> _______________________________________ _______________________________________________ Python-bugs-list mailing list Unsubscribe: http://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com
