http://gcc.gnu.org/bugzilla/show_bug.cgi?id=56493
Bug #: 56493
Summary: Performance regression in google dense hashmap
Classification: Unclassified
Product: gcc
Version: 4.7.1
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: c++
AssignedTo: [email protected]
ReportedBy: [email protected]
When compared to gcc-4.6.2, gcc-4.7.1 shows about a 10-20% performance
regression when inserting into a google dense hashmap in a tight loop. A small
sample program is attached and was compiled with '-O3' and on a linux x86_64
box (using -std=gnu++0x, as required by sparsehash). Potentially related, the
generated binary under gcc-4.7 is also over 50% bigger.