https://gcc.gnu.org/bugzilla/show_bug.cgi?id=63791
Andrew Pinski <pinskia at gcc dot gnu.org> changed:
What |Removed |Added
----------------------------------------------------------------------------
Status|REOPENED |RESOLVED
Resolution|--- |INVALID
--- Comment #7 from Andrew Pinski <pinskia at gcc dot gnu.org> ---
The reason is because -mavx2 is not a tuning option. It does not or should not
change the tuning of the code. It just enables an ISA feature of the produced
code. If you want explicit tuning for intel cores, use -mtune=intel.
The reason why -mtune=intel can change in the future is because Intel cores are
not set in stone and newer intel cores can and will have different tuning
parameters. -mtune=intel is based on the current majority of intel cores at
the released time of GCC. So if say 10 years down the line, some newer intel
core which has a major tuning difference to the current ones; -mtune=intel will
change for those cores rather than stay constant for the ones now (2015).
