Some benchmark comparison of gcc4.5 and dragonegg (was dragonegg in FSF gcc?)

Robert Dewar dewar@adacore.com
Wed Apr 21 18:32:00 GMT 2010


Manuel López-Ibáñez wrote:
> On 21 April 2010 19:11, Vladimir Makarov <vmakarov@redhat.com> wrote:
>> I don't think we should be too much worried about it.  GCC looks good in
>> comparison with other industrial compiler with compile time point (and code
>> size too) of view (e.g. SunStudio compiler is about 2 times slower and
>> generates worse code on x86/x86_64 according to my benchmarking 2 years ago,
>> Intel is also slower but generates much better code than gcc).
> 
> There is the perception that GCC is too slow and every release it gets
> much slower for not significant gain. At some point one has to start
> asking whether there is something that can be done to alleviate this.
> Either by showing that in fact there is a significant gain, or by
> improving compilation speed. But we should be worried.

We (here we = the commercial company AdaCore) would be worried if
ANY of our customers were worried, but they are not, they see a
continuous effective improvement in compile speed using the latest
available hardware, and it's not a factor for them.

> So do you think that the differences in compilation speed can be
> explained mostly by lack of optimization features in LLVM?

Nobody said that, the explanation is of course FAR more complex,
and to some extent it may be a matter of orientation and
enthusiasm. There is more enthusiasm in the gcc community for
implementation new optimizations to improve performance, than
in speeding up the existing compiler, which is quite
understandable.



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