[Bug c++/56493] Performance regression in google dense hashmap

[jakub at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=56493

--- Comment #13 from Jakub Jelinek <jakub at gcc dot gnu.org> ---
Created attachment 30312
  --> http://gcc.gnu.org/bugzilla/attachment.cgi?id=30312&action=edit
gcc49-pr56493.patch

Untested patch that in the FE restores the performance on the simplified
testcase.  Haven't tried the original.  Of course, having this optimization be
performed in GIMPLE will be much more worthwhile, but likely not backportable.