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

[redi at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=60976

Jonathan Wakely <redi at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|UNCONFIRMED                 |NEW
   Last reconfirmed|                            |2016-01-11
     Ever confirmed|0                           |1

--- Comment #32 from Jonathan Wakely <redi at gcc dot gnu.org> ---
I'm confirming this, as we definitely have slowed down (although I see less 2x
difference for the attached testcase), but that doesn't mean we can fix it.

I've committed a change on trunk that adds a partial specialization of
std::allocator_traits<sd::allocator<T>> which helps a bit.