Polyhedron benchmark on Opteron

[Tim Prince]

François-Xavier Coudert wrote:

> I wanted to report some results for the Polyhedron benchmark** on
> Opteron (hardware details at the bottom of this mail). 
> Unfortunately, there are also tests for which Intel is a clear winner:
>  -- aermod, by 44%
>  -- air, by 30%

>  -- nf, by 29%
> 
The differences aren't so large on the Core 2 Duo.
gprof profiling doesn't capture the deficits in gfortran performance. 
In aermod, with either ifort or gfortran, less than 50% of the time is 
spent in the code covered by gprof profiling.  Most of the time spent by 
the ifort version of air is captured in gprof profile, but the gfortran 
version spends significant unaccounted time.  The profile for the 
gfortran version of nf allocates by far the largest time segment to a 
mysterious frame_dummy symbol.

Some day, I'll check aermod and air with VTune, to look for the 
mysterious extra time.