On Sunday 07 June 2009 07:20:00 Ilya A. Volynets-Evenbakh wrote:
Were results different (as in the way one would expect) with earlier
versions of
gcc?
I didn't try. I added this compilation option recently.
Regards,
Shlomi Fish
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
--
-
Shlomi Fish http://www.shlomifish.org/
http://www.shlomifish.org/humour/ways_to_do_it.html
God gave us two eyes and ten fingers so we will type five times as much as we
read.
___
Haifux mailing list
Haifux@haifux.org
http://hamakor.org.il/cgi-bin/mailman/listinfo/haifux
