[Python-Dev] Re: Who cares about the performance of these opcodes? (original) (raw)

Bob Ippolito bob at redivi.com
Wed Mar 10 07:01:22 EST 2004

On Mar 10, 2004, at 12:10 PM, Michael Hudson wrote:

"A.M. Kuchling" <amk at amk.ca> writes:

On Tue, 09 Mar 2004 08:59:52 -0500, Phillip J. Eby <pje at telecommunity.com> wrote: I personally don't think it'll help much, if the goal is to reduce cache misses. After all, the code is all still there. But, it should not do

For a planned PyCon lightning talk, I'm benchmarking various combinations of optimizer options. One interesting result: CVS Python gets 25997 pystones on my machine when compiled with -O3 (the default), but 26707 when compiled with gcc's -Os flag. -Os optimizes for size, running the subset of the -O2 optimizations that don't increase code size. What architecture? I played around on my ibook with various compilation options and running with -fprofile-arcs and so on and basically came to the conclusion that nothing made very much difference (once past -O2). Can't remember if I tried -Os.

If you really want faster code you should tell the compiler about the particular architecture you need to run it on. For example, Apple's gcc 3.3 has an optimization flag named "-fast" that will (supposedly) produce fast non-PIC code that will only run on 64bit G5 processors (but can be scaled back to G4 with -mcpu=7450, and probably back to G3 in a similar way).

-bob

More information about the Python-Dev mailing list