http://gcc.gnu.org/bugzilla/show_bug.cgi?id=51798
--- Comment #19 from Andrew Macleod <amacleod at redhat dot com> 2012-01-27 12:49:27 UTC --- (In reply to comment #17) > (In reply to comment #13) > > Any code that explicitly calls __sync_* in > > libstdc++-v3 has introduced a performance regression. > > But if it happens in code that is executed only rarely (e.g. the EH code will > be dominated by time spent in the unwinder, not any barriers), then it might > not be even measurable. So I think we should first change atomicity.h and > only > if you can come up with a testcase which shows a significant regression for > the > libsupc++ or parallel bits, we should change those too at this point. We are > in stage4. Precisely my thoughts... Its not a regression if it isn't measurable, and we want to change as little as we possibly can at this stage. The patch is what I was thinking. I presume it generates the same code power use to get?
