GCC-4.5.0 and LLVM-2.7 were released recently. To understand
where we stand after releasing GCC-4.5.0 I benchmarked it on SPEC2000
for x86/x86-64 and posted the comparison of it with the
previous GCC releases and LLVM-2.7.
Even benchmarking SPEC2000 takes a lot of time on the fastest
machine I have. So I don't plan to use SPEC2006 for this in near
future.
You can find the comparison on
http://vmakarov.fedorapeople.org/spec/ (please just click links at the
bottom of the left frame starting with link "GCC release comparison").
If you need exact numbers, please use the tables (the links to them
are also given) which were used to generate the corresponding bar
graphs.
In general GCC-4.5.0 became faster (upto 10%) in -O2 mode. This is
first considerable compilation speed improvement since GCC-4.2.
GCC-4.5.0 generates a better (1-2% in average upto 4% for x86-64
SPECFP2000 in -O2 mode) code too in comparison with the previous
release. That is not including LTO and Graphite which can gives even
more (especially LTO) in many cases.
GCC-4.5.0 has new big optimizations LTO and Graphite (more
accurately graphite was introduced in the previous release).
Therefore I ran additional benchmarks to test them.
LTO is a promising technology especially for integer benchmarks for
which it results in smaller and faster code. But it might result in
degradations too on SPECFP2000 mainly because of big degradations on a
few benchmarks like wupwise or facerec. Another annoying thing about
LTO, it considerably slows down the compiler.