This is the mail archive of the
gcc-bugs@gcc.gnu.org
mailing list for the GCC project.
[Bug c++/60976] Compilation with G++ 4.9.0 is 2-3 times slower than with 4.8.2
- From: "redi at gcc dot gnu.org" <gcc-bugzilla at gcc dot gnu dot org>
- To: gcc-bugs at gcc dot gnu dot org
- Date: Thu, 09 Apr 2015 09:12:08 +0000
- Subject: [Bug c++/60976] Compilation with G++ 4.9.0 is 2-3 times slower than with 4.8.2
- Auto-submitted: auto-generated
- References: <bug-60976-4 at http dot gcc dot gnu dot org/bugzilla/>
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=60976
--- Comment #17 from Jonathan Wakely <redi at gcc dot gnu.org> ---
(In reply to Rene Koecher from comment #14)
> I agree on your point here, however shouldn't an unchanged codebase (and
> we're not using C++11 features or -std=c++11 yet) at least keep the same
> performance?
No, because the standard library headers you include are not unchanged if you
upgrade the compiler.
> It's understandable that standards compliance can counter performance but I
> honestly wouldn't expect the compiler performance of older code / code not
> using the new features to drop that drastically..
Please provide a testcase demonstrating the problem with pre-C++11 code.