[Bug c++/95400] New: -march=native and -march=icelake-client produce different results on icelake client

[travis.downs at gmail dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=95400

            Bug ID: 95400
           Summary: -march=native and -march=icelake-client produce
                    different results on icelake client
           Product: gcc
           Version: 9.2.1
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: c++
          Assignee: unassigned at gcc dot gnu.org
          Reporter: travis.downs at gmail dot com
  Target Milestone: ---

On an Ice Lake client machine, using -O3 -march=native produces 512-bit AVX-512
instructions, whereas -O3 -march=icelake-client produces 256-bit instructions.

Since this machine *is* Ice Lake client, I would expect both options to do the
same thing.