atlas depends on gcc43 *and* gcc44 ???
Joshua Root
jmr at macports.org
Wed Jun 2 23:36:53 PDT 2010
On 2010-6-3 14:59 , vincent habchi wrote:
> Le 2 juin 2010 à 23:13, Stephen Langer a écrit :
>
>> I was wondering why anything depends on atlas at all. Is atlas noticeably better than the lapack and blas routines in the Accelerate framework? I couldn't find any comparisons on-line.
>
> I am unsure. But, as long as Apple does not state that its Blas and Lapack libraries are OpenCL based, in which case they may be hundred times quicker that CPU-thread-based Atlas, I am lead to believe that Atlas compiled with the latest gcc45 should be more efficient than Apple blas or lapack, most probably generated with gcc42 (the last GPL2 version) and backward-compatible with MacOS 10.4 or 10.5; Maybe they can get better efficiency with Clang/LLVM. However, I faintly remember comparing the Atlas built-in tests, and there was a clear gap between gcc43 and gcc44.
>
> It should not be very difficult to build up a test, like finding the eigenvalues of a random but symmetric definite positive matrix of great size (say : 50,000 x 50,000 or more) in Xcode, and link either with the built-in framework or our Atlas.
>
> Cheers
> Vincent
>
> PS : Does Apple provide scipy in its Python distribution?
No, 'import scipy' fails, which agrees with this list:
<http://opensource.apple.com/source/python_modules/python_modules-21/>
- Josh
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