[Bug libstdc++/54075] [4.7.1] unordered_map insert 3x slower than 4.6.2

[fdumont at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=54075

--- Comment #24 from François Dumont <fdumont at gcc dot gnu.org> 2012-07-29 17:06:25 UTC ---
Author: fdumont
Date: Sun Jul 29 17:06:21 2012
New Revision: 189941

URL: http://gcc.gnu.org/viewcvs?root=gcc&view=rev&rev=189941
Log:
2012-07-29  François Dumont  <fdumont@gcc.gnu.org>

    PR libstdc++/54075
    * include/bits/hashtable_policy.h
    (_Prime_rehash_policy::_M_next_bkt): Add a growth factor set to 2
    to boost growth in the number of buckets.
    * testsuite/performance/23_containers/insert/unordered_set.cc: New.

Added:
   
branches/gcc-4_7-branch/libstdc++-v3/testsuite/performance/23_containers/insert/unordered_set.cc
Modified:
    branches/gcc-4_7-branch/libstdc++-v3/ChangeLog
    branches/gcc-4_7-branch/libstdc++-v3/include/bits/hashtable_policy.h