[Bug c++/60976] Compilation with G++ 4.9.0 is 2-3 times slower than with 4.8.2

trippels at gcc dot gnu.org gcc-bugzilla@gcc.gnu.org
Thu Apr 9 09:47:00 GMT 2015


--- Comment #18 from Markus Trippelsdorf <trippels at gcc dot gnu.org> ---
(In reply to Jonathan Wakely from comment #15)
> For the program in comment 5 most of the difference in compile-time is
> caused by the allocator-aware container requirements (additional
> constructors which need to be instantiated for every explicit instantiation
> in the program and more complicated definitions for copy/move/swap). These
> changes are required for C++11 conformance, and I don't see any obvious way
> to implement them without affecting compile times.

Just to confirm, the regression started with r204848 (~25% compile time
slowdown with -O0 on sandybridge).

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