[LLVMdev] FYI: Phoronix GCC vs. LLVM-GCC benchmarks

Török Edwin edwintorok at gmail.com
Fri Sep 18 00:59:09 PDT 2009

On 2009-09-16 17:32, Olivier Meurant wrote:
> On Wed, Sep 16, 2009 at 3:46 PM, Stefano Delli Ponti
> <stefano.delliponti at gmail.com <mailto:stefano.delliponti at gmail.com>>
> wrote:
>     I don't know what you think about this, but shouldn't it be more
>     meaningful to make these tests with -O3? I mean, we ought to make the
>     comparisons with the highest level of optimization available for
>     both of
>     the compilers. It is difficult to compare an intermediate level.
> A quick test confirms that the 40% difference stays even with an -O3
> switch on both compilers.
> I just "choose" -O2 as it's the default of the original makefile.

It would be interesting to see if LLVM has improved since 2.5 on this
benchmark, could you try the prerelease here?

A 40% performance loss is bad, something should be done about it for
LLVM 2.7 (if it is too late for 2.6 already).

Best regards,

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