-mavx option

[Ulrich Drepper]

I think gcc is missing an option since -mavx controls two different
things.  First, the generation of VEX-encoded instructions.  Second,
the use of ymm registers.  The latter is not always available when the
former is and using VEX-encoded instructions by themselves can have an
advantage.  Currently, when OSXAVE is not available (use xgetbv to
test etc etc) then I cannot use code which gcc generates with -mavx
even though I am only interested in the VEX encoding.

Could we have a -mvex option which is automatically implied in -mavx?