On Tue, Apr 12, 2011 at 04:37:42PM +0200, Richard Guenther wrote: > On Tue, Apr 12, 2011 at 4:32 PM, Nathan Froyd <froy...@codesourcery.com> > wrote: > > Thanks. I may go twiddle that patch to do something similar to mine and > > submit that. Do you use your patch for checking that the same set of > > optimizations get performed, then? I'm interested in using the > > statistics for identifying passes that don't buy us much across a wide > > variety of codebases. (Suggestions for suitable ones welcome!) > > Yes, I used it exactly for that. And also to verify that passes don't > do anything if replicated (well, for those that shouldn't at least). > > Don't expect any low-hanging fruit though ;) I catched all of it already. > > Candidates are obviously SPEC and GCC itself. I also use tramp3d > of course. That said, even if a pass does nearly nothing we often > have testcases that need it ...
True, but maybe those testcases should be adjusted--per-pass flags, rather than blindly assuming -O2 includes them. And it's not clear to me that the statistics_counter_event infrastructure really helps catching do-nothing passes, since it doesn't record stats that increment by zero... -Nathan
