Damien Morton wrote:
Christian Tismer wrote: So what I would like to try is to merge all opcodes which have exactly the same pattern into one case, which then does the common preparation stuff and postprocessing including error handling, but internally dispatches on the function to be called.
I tried this on the 2.3a2 source, modifying it to implement your idea.
This was implemented on top of the LOAD_FAST_n, etc, changes.
No luck - it makes the code slower by nearly 5%, decreasing a base 22300 PyStones to 21100 PyStones. That is, the idea of using function pointers. I imagine that a case statement would be even slower.
Too bad. Hmm. Would you mind to send me the source code? I'd like to see what code is generated.
I didnt implement the table of function pointers as one monolithic table, as the unary and binary functions have different signatures.
They could live in the same table, but probably this doesn't change memory layout at all. A case statement might or might not be slower, a branch might become a little more predictable than though a function table. And then, five percent is not bad. Did you measure how much code you saved in the binary? thanks - chris -- Christian Tismer :^) <mailto:tismer@tismer.com> Mission Impossible 5oftware : Have a break! Take a ride on Python's Johannes-Niemeyer-Weg 9a : *Starship* http://starship.python.net/ 14109 Berlin : PGP key -> http://wwwkeys.pgp.net/ work +49 30 89 09 53 34 home +49 30 802 86 56 pager +49 173 24 18 776 PGP 0x57F3BF04 9064 F4E1 D754 C2FF 1619 305B C09C 5A3B 57F3 BF04 whom do you want to sponsor today? http://www.stackless.com/