Compilation performance comparison of 3.5.0 and TreeSSA trees on MICO sources as requested in: [tree-ssa] Merge status 2004-05-03

[Diego Novillo]

On Tue, 2004-05-04 at 16:50, Karel Gardas wrote:

> Conclusion: compile time regressions for both -O0 and -O2 compilation.
> 
Thanks.  -O0 is a known loser right now.  The gimplification process
tends to create extremely bloated RTL.  That can only be fixed by
introducing simplistic tree optimization passes at O0.  I see this as a
post-merge exercise, as well.

As far as the -O2 regressions, do you have the -ftime-report output? 
IMO, these C++ problems are better addressed once tree-ssa is in
mainline.  If it's similar to the other C++ applications showing compile
time regressions, this will need work in a bunch of places inside GCC
(memory allocator, parser, trees, etc).


Diego.