On Mon, 18 Jun 2012 21:31:27 +0200 Maciej Fijalkowski <fij...@gmail.com> wrote: > On Mon, Jun 18, 2012 at 5:04 PM, Antoine Pitrou <solip...@pitrou.net> wrote: > > > On Mon, 18 Jun 2012 15:28:24 +0100 > > Mark Shannon <m...@hotpy.org> wrote: > > > > > > But do they? The results of benchmarking would seem to suggest (at least > > > on my test machine) that overly-sparse dicts are slower. > > > Possibly due to increased cache misses. > > > > Or, at least, they are not faster. See the synthetic experiments in > > http://bugs.python.org/issue10408 > > > > That said, Raymond might have witnessed different results at the time. > > Hardware evolves quickly and the parameters change (memory latency > > today is at least 50+ CPU cycles, which is quite a lot of wasted work on > > a pipelined superscalar CPU). > > > > Regards > > > > Antoine. > > > > > More like 200-500 CPU cycles on modern CPUs.
You are right. I was thinking 50 nanoseconds (which for a - relatively high-end - 3GHz CPU puts us at 150 cycles). Regards Antoine. _______________________________________________ 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
