Polyhedron benchmark on Opteron

[François-Xavier Coudert]

>> 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