Were results different (as in "the way one would expect") with earlier versions of gcc?
Shlomi Fish wrote: > I'm getting strange results (and counter-intuitive ones) when trying to > compile a program using gcc-4.4.0-3mnb2 on Mandriva Linux Cooker. > > The program in question is: > > https://svn.berlios.de/svnroot/repos/fc-solve/trunk/fc-solve/source > > (you can checkout it using "svn co"). > > And I'm getting the following benchmark timings: (in seconds) > > {{{{{{ > dump:126.027262926102 > dump-2:124.866523981094 > dump-3:125.149952888489 > dump-4:125.010930776596 > dump-aft-reboot:127.221956968307 > dump-flip:123.10272693634 > dump-flip-2:121.934360027313 > dump-flip-3:121.98522400856 > dump-old:130.334769010544 > dump-old-aft-reboot:122.411857128143 > }}}}}} > > dump-old is of an old revision before I rebooted. dump-old-aft-reboot is the > same version after I reboot the computer. > > The dump-flip's are after doing "./Tatzer -l p4b" and then "make" (and "make > install") and then running: > > ./freecell-solver-range-parallel-solve 1 32000 500 -l gi > > The dump-[234] are after doing "./Tatzer -l p4b --without-flip". What this > flag does is define the FCS_WITHOUT_CARD_FLIPPING macro, which in turn > toggles > some #ifndef's in the code that eliminate a lot of code. I verified that with > "--without-flip" binaries are smaller. > > My question is: why is the --without-flip binaries slower than the ones with > the flipping logic? So far my best bet is that with the flipping logic > enabled > (but underused) the code aligns to have fewer cache misses and that it is > just > a co-incidence that this is the case. > > I'll appreciate any insights. > > Regards, > > Shlomi Fish > > -- Ilya A. Volynets-Evenbakh http://www.total-knowledge.com _______________________________________________ Haifux mailing list Haifux@haifux.org http://hamakor.org.il/cgi-bin/mailman/listinfo/haifux