This is the mail archive of the fortran@gcc.gnu.org mailing list for the GNU Fortran project.


Index Nav: [Date Index] [Subject Index] [Author Index] [Thread Index]
Message Nav: [Date Prev] [Date Next] [Thread Prev] [Thread Next]
Other format: [Raw text]

Re: Polyhedron benchmark on Opteron


Options used are :
 * gfortran -march=k8 -ffast-math -funroll-loops -static -O3
 * ifort -O3 -xW -ipo -static -V


If -ipo means interprocedure optimization, then this isn't something for someone new to gcc/gfortran to do. What are the comparisons if -ipo is removed?

Yes, -ipo means interprocedure optimization. But in my experience, it seldom makes a huge difference. Last time I took the time to profile a polyhedron benchmark, it was AERMOD and I discovered we spent 20% of the time call the (since inlined) string copying function in libgfortran.

Anyway, I'll launch a benchmark without -ipo, and I'll report back.

FX


Index Nav: [Date Index] [Subject Index] [Author Index] [Thread Index]
Message Nav: [Date Prev] [Date Next] [Thread Prev] [Thread Next]