[Llvm-bgq-discuss] bgclang r180241-20130423 on vesta/mira

[Hal Finkel]

Hi everyone,

I've installed a new version on vesta/mira (r180241-20130423). This version picks up the last 1.5 months of performance work I've done on the PowerPC backend, as well as a few QPX-specific improvements. Notably, there are a number of fast-math-specific improvements (including autovectorization of division and sqrt), and so if you can afford some error in the last bit or two, try compiling with -ffast-math and see if that helps.

xlC enables its fast-math mode by default at -O3 (unless you specifically specify -qstrict), but that's cheating ;) That having been said, this is a user facility, so if you all would like, we can cheat too.

This new version of bgclang also supports (from upstream) -Ofast, which is a combination of -O3, -ffast-math and -fstrict-aliasing.

I'll send out updated patches in the near future.

 -Hal

-- 
Hal Finkel
Postdoctoral Appointee
Leadership Computing Facility
Argonne National Laboratory