Changing default compiler for Atlas from gcc47 to clang-3.3 on AVX capable machines

[Joshua Root]

On 2013-3-7 02:03 , Vincent Habchi wrote:
> Ryan,
> 
>> But atlas also uses fortran, right? Is it more important for atlas to have better performance by compiling with clang, or to use fortran by compiling with gcc?
> 
> Atlas uses Fortran only to build the BLAS/Lapack fortran API. The Fortran compiler performance is irrelevant to the whole performance, and Atlas can also be built without Fortran (but, of course, you only get the C API).
> 
> The new Portfile clamps the optimization flag of gfortran to -sse4.2 in order to avoid AVX instruction generation by gfortran47 or above.

Does dragonegg use the llvm-mc assembler?

- Josh