Re: [boost] uBLAS gcc performance question

From: Simon J. Julier (sjulier_at_[hidden])
Date: 2002-06-26 07:59:38

Dear Joerg,

>Please check, whether the preprocessor symbol NDEBUG is defined. NDEBUG in
>turn defines NUMERICS_USE_ET, which enables uBLAS release mode....

Thanks - that definitely makes a significant difference in speed. The 
results I'm seeing are:

bench_3
prod (matrix, matrix)
C array
elapsed: 0.05 s, 113.869 Mflops
c_matrix safe
elapsed: 0.07 s, 81.3348 Mflops
c_matrix fast
elapsed: 0.07 s, 81.3348 Mflops
matrix<bounded_array> safe
elapsed: 0.08 s, 71.1679 Mflops
matrix<bounded_array> fast
elapsed: 0.06 s, 94.8906 Mflops
matrix<unbounded_array> safe
elapsed: 0.071 s, 80.1892 Mflops
matrix<unbounded_array> fast
elapsed: 0.07 s, 81.3348 Mflops
matrix<std::vector> safe
elapsed: 0.07 s, 81.3348 Mflops
matrix<std::vector> fast
elapsed: 0.08 s, 71.1679 Mflops

These results also include the compiler settings suggested by Peter 
Schmitteckert.

>P.S.: Yes I know, this could be the first FAQ ;-)

Please!

Cheers,

Simon