CentOS - Feb 2009 - fotran 77 with amd64 technology

What is the right way to compile a fortran 77 file using the amd64 bits
technology? If I write f77 -m64 -march=opteron file.f and then run a.out, the
time of execution is so slow as if it I ?had?nt called to 64bits option. what is
happening?
?


      
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Pavel Ritto wrote:
> What is the right way to compile a fortran 77 file using the amd64 
> bits technology? If I write f77 -m64 -march=opteron file.f and then 
> run a.out, the time of execution is so slow as if it I  had?nt called 
> to 64bits option. what is happening?
>  
>
>
I thought the Gnu Fortran compiler was called g77 ? ... oh, I see, f77 
is a link to g77.   yes, -m64 should generate x86_64 code...    I dunno 
what -march=opteron does.

otherwise, insufficient information to diagnose your problem.   was this 
fortran program written for GCC F77 ?   is it slow because its CPU bound 
or is it slow because its swapping?



(note, btw, I haven''t actually touched fortran since the 1970s)