On Fri, Aug 14, 2015 at 3:35 PM, Abe Skolnik <abe_skol...@yahoo.com> wrote: > [Alan wrote:] > >> Interesting, thanks. For what kind of architecture are these - > > You are welcome. > > You raised 2 or 3 good points, I think. > > First: the numbers are all from builds on and for the AMD64 ISA, AKA > "x86_64". My apologies for forgetting to mention that vital fact. > > Second: I did not tell the SPEC build system to use any particular "-march" > or "-mtune" flags, and AFAIK it [SPEC] did not add any that I didn`t specify. > In other words, those compiler-tuning values were almost certainly at their > GCC defaults. > > [A question about the preceding: is "-march=native" the default nowadays, at > least on GNU/Linux? AFAIK the default GCC behavior is (still?) to > generate code for the most generic form of the target ISA unless an explicit > flag overrides this.] > > Third: the server in question has Intel silicon for its CPUs. If an implicit > "-march=native" or similar is suspected of having been a factor, then please > let me know and I`ll report back on the specifics. [I am at home right now, > so I have no easy way of getting that data right now.]
Ah, so for a meaningful comparison -march=native should be used. Otherwise we don't get much store if-conversion anyway. Richard. > >> specifically: with/out masked/gathering loads/stores ?? > > > TTBOMK, generic AMD64/x86_64 does _not_ have the gathering stuff and the very > latest from Intel _does_. > > Sorry, but I don`t know about the masked form[s]. If that`s important to > know, then please tell me and I will investigate. > > Regards, > > Abe
