[Users] problem with ifort 10 compiler

[Thomas Radke]

Erik Schnetter wrote:
> On Jan 16, 2008, at 06:26:26, Christian Reisswig wrote:
> 
>> Hi,
>>
>> when I try to compile Cactus, I get problems compiling Fortran  code, 
>> since
>> Cactus sets an optimization option "-xN".
>> This option doesn't seem to be supported by the Intel Fortran 10  
>> compiler.
>> So I guess the -xN option has to be replaced by -xW.
> 
> 
> 
> I think the option should be omitted.  Which of these options should  be 
> used depends on the system; Cactus should either autoconfigure the  
> system and optimise for the system where it is compiled, or should  (by 
> default) produce binaries which run everywhere.  -xW seems to  break for 
> Pentium III systems -- I don't think they are in widespread  use, but 
> you never know.
> 
> We could use -axP, which generates code that runs everywhere but is  
> optimised for modern machines.  For example, -fast also implies -xP.

I suggest to omit any processor-dependent optimisation flags and just 
use '-O2 -ip' (same Cactus default optimisation flags as for C/C++ code).

I just ran a BSSN_MoL benchmark comparing a '-O2 -ip' configuration 
against '-O2 -xN -ip'. It showed no difference in runtime on Damiana.

-- 
Cheers, Thomas.