This is the mail archive of the mailing list for the GCC project.

Index Nav: [Date Index] [Subject Index] [Author Index] [Thread Index]
Message Nav: [Date Prev] [Date Next] [Thread Prev] [Thread Next]
Other format: [Raw text]

[BENCHMARK] comparing GCC 3.4 and 4.0 on an AMD Athlon-XP 2500+

Hi all,

I have some preleminary benchmark results comparing 3.4(.3) with 4.0.0, including some optimization option permuations.

rt = runtime
bt = buildtime

-lu == -funroll-loops
-uaat == -funit-at-a-time
-vect == -ftree-vectorize
-oft == -fomit-frame-pointer
-x ==  -funroll-loops -fpeel-loops -fpeel-loops -funswitch-loops
       -ftree-vectorize -ftracer -fomit-frame-pointer

-x-uaat == -x + -uaat

A short summary:

4.0 seems to be very good at modern C++ code, especially involving a lot of templates.

The -Os switch's generated code speed degenerated by magnitudes for C++ code (look at Botan and tramp3d).

4.0 seems to have problems catching up at C code where 3.4(.3) was previously yielding good results - e.g openssl, libmad and gnupg seem to be a challenge for GCC.

Of course all hand written assembly was disabled in those benchmarks, to review what GCC is able to genereate out of the generic C code ...

Feedback welcome - yours,

René Rebe - Rubensstr. 64 - 12157 Berlin (Europe / Germany)
            +49 (0)30  255 897 45

Index Nav: [Date Index] [Subject Index] [Author Index] [Thread Index]
Message Nav: [Date Prev] [Date Next] [Thread Prev] [Thread Next]