Am Donnerstag, den 25.08.2011, 11:34 +0200 schrieb Benedikt Meurer: > On Aug 25, 2011, at 10:02 , Benedikt Meurer wrote: > > >>> - http://ps.informatik.uni-siegen.de/~meurer/tmp/compiletime_timings.pdf > >>> contains a comparison of the ocamlopt invocations. > >>> - http://ps.informatik.uni-siegen.de/~meurer/tmp/runtime_timings.pdf > >>> contains comparison of the generated code. > >>> > >>> As can be seen from the results, amd64 is more sensitive to register > >>> allocator changes than i386. > >> > >> Well, this particular i386 CPU model is a strange guy - Northwoods have > >> this extremely long pipeline, which is very sensitive to unforeseen > >> jumps. It would be more interesting to see this test on a modern CPU in > >> i386 mode. My guess is that it behaves then more like amd64. > > > > Modern CPUs most probably don't run ocaml in 32bit mode, but more likely in > > long mode. That's why we choose to run the i386 on "real 32bit hardware", > > where the ocaml i386 port is actually used.
Right. However, if you look at new 32-bit-only CPUs like older Atoms these base on modern cores where only some of the circuits were omitted that are needed for 64-bit execution. > > > > I'll rerun the benchmark in 32bit mode on a modern cpu to see how things > > change. > > Reran the benchmark with 32bit ocaml on the MBP (Early 2011), results are > available at: > > http://ps.informatik.uni-siegen.de/~meurer/tmp/linscan-i7-i386-timings.pdf Hard to interpret. I have the impression that the compile times for graph coloring on i386 are lower than on amd64 - has maybe to do with the number of registers - but those for linear scanning are about the same. (I'm comparing here with the amd64 numbers taken on the same machine.) The graphs for the runtimes are on a logarithmic scale. Do you also have raw numbers? Gerd > > Benedikt > > > -- ------------------------------------------------------------ Gerd Stolpmann, Darmstadt, Germany [email protected] Creator of GODI and camlcity.org. Contact details: http://www.camlcity.org/contact.html Company homepage: http://www.gerd-stolpmann.de *** Searching for new projects! Need consulting for system *** programming in Ocaml? Gerd Stolpmann can help you. ------------------------------------------------------------ -- Caml-list mailing list. Subscription management and archives: https://sympa-roc.inria.fr/wws/info/caml-list Beginner's list: http://groups.yahoo.com/group/ocaml_beginners Bug reports: http://caml.inria.fr/bin/caml-bugs
