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Re: Comparison of GCC-4.6.1 and LLVM-2.9 on x86/x86-64 targets
- From: Lawrence Crowl <crowl at google dot com>
- To: Vladimir Makarov <vmakarov at redhat dot com>
- Cc: "gcc.gcc.gnu.org" <gcc at gcc dot gnu dot org>
- Date: Fri, 9 Sep 2011 16:30:06 -0700
- Subject: Re: Comparison of GCC-4.6.1 and LLVM-2.9 on x86/x86-64 targets
- References: <4E678A9B.3040303@redhat.com>
On 9/7/11, Vladimir Makarov <vmakarov@redhat.com> wrote:
> Some people asked me to do comparison of GCC-4.6 and LLVM-2.9 (both
> released this spring) as I did GCC-LLVM comparison in previous year.
>
> You can find it on http://vmakarov.fedorapeople.org/spec under
> 2011 GCC-LLVM comparison tab entry.
The format of these graphs exaggerates differences. The reason is
that our hind brains cannot help but compare the heights of bars and
ignore the non-zero bases. In short, non-zero based graphs are lies.
So, please 0-base all the graphs. The graphs should show compilation
time from 0 up, execution time from 0 up, SPEC score from 0 up, etc.
A consequence is that you will get rid of the "change" graphs.
In my mind, an interesting graph would be to plot the execution
time of the benchmarks as a function of the compile time of the
benchmarks. This graph would show you, in particular, what you
buy or lose by changing compilers and/or optimization/debug levels.
--
Lawrence Crowl