This is the mail archive of the
gcc-bugs@gcc.gnu.org
mailing list for the GCC project.
[Bug libstdc++/51798] [4.7 regression] libstdc++ atomicity performance regression due to __sync_fetch_and_add
- From: "amacleod at redhat dot com" <gcc-bugzilla at gcc dot gnu dot org>
- To: gcc-bugs at gcc dot gnu dot org
- Date: Thu, 26 Jan 2012 13:57:56 +0000
- Subject: [Bug libstdc++/51798] [4.7 regression] libstdc++ atomicity performance regression due to __sync_fetch_and_add
- Auto-submitted: auto-generated
- References: <bug-51798-4@http.gcc.gnu.org/bugzilla/>
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=51798
--- Comment #12 from Andrew Macleod <amacleod at redhat dot com> 2012-01-26 13:57:56 UTC ---
(In reply to comment #11)
> What about the other files that use __sync_* in libstdc++?
I would change the bare minimum... Every change is a risk of some sort this
late n the game. The only reason to consider this change was the unacceptable
performance regression on power which was reported. If it hasn't been
reported, I'd leave it alone personally :-)
I hope to replace *all* __sync calls everywhere in the toolchain with __atomic
for 4.8. That way there is also time to evaluate the proper model for each one
and test it.