> I believe all required gcc support -mtune= and -mcpu= is deprecated.
No this is true only for Intel, PowerPC still uses -mcpu. This change would
disable the existing -with-cpu= optimization available for PowerPC.
The equivalent for Intel is -march= because we want to select source
optimizations based on ISA version or processor extention. -mtune is
implied, but can and should be specified separately (via CFLAGS).
If you want to change this you need to condition use of -mcpu vs -march
based on $machine or $base_machine.