https://gcc.gnu.org/bugzilla/show_bug.cgi?id=80813
--- Comment #1 from Andrew Pinski <pinskia at gcc dot gnu.org> --- Note the code is worse in GCC 11+, there seems to be a missing optimization on the gimple level ...
[Bug target/80813] x86: std::vector::operator[] could be somewhat faster using BT instead of SHL
pinskia at gcc dot gnu.org via Gcc-bugs Tue, 20 Jul 2021 22:45:41 -0700
