Re: GCC still getting a lot slower

[Jan Hubicka <jh at suse dot cz>]

> On Tue, 31 Dec 2002, Nathanael Nerode wrote:
> > Can we test compile time change of some *fixed* piece of code, perhaps?
> 
> PR 8361 (http://gcc.gnu.org/cgi-bin/gnatsweb.pl?cmd=view&pr=8361),
> which is basically the old PR 3083, is here for anyone to use. ;-)
> 
> Gerald
> 
> PS: It's no longer a completely fixed piece of code, as it's not possible
> to have preprocessed source that is forwards or backwards compatible with
> or from current mainline, but I have included two preprocessed files now.
It would be perhaps good idea to include the performance of preprocesing
as well.  That would fix the compatibility too.

For C performance I think it can be practical to just benchmark linux
kernel build - it is fixed piece as it does not include any external
headers, large enought to make measurements hopefully stable enought and
tests performance of "usual hand writen C program" that (for C) is about
the most important.  Fixing performance of computer generated code is
important too, but it usually has different problem (like computed
jumps, large switch statements and so on) and I tend to believe that
still most of code is hand writen.
I did some oprofiling in the past on this but didn't find anything
obvious to fix.

For C++ I am not aware of something like that.
> -- 
> Gerald "Jerry"   pfeifer@dbai.tuwien.ac.at   http://www.pfeifer.com/gerald/