PING [Patch][Middle-end]Add -fzero-call-used-regs=[skip|used-gpr|all-gpr|used|all]

[H.J. Lu]

On Fri, Sep 4, 2020 at 11:09 AM Segher Boessenkool
<segher@kernel.crashing.org> wrote:
>
> On Fri, Sep 04, 2020 at 10:34:23AM -0700, H.J. Lu wrote:
> > > You probably have to do this for every target separately?  But it is not
> > > enough to handle it in the epilogue, you also need to make sure it is
> > > done on every path that returns *without* epilogue.
> >
> > This feature is designed for normal return with epilogue.
>
> Very many normal returns do *not* pass through an epilogue, but are
> simple_return.  Disabling that is *much* more expensive than that 2%.

Sibcall isn't covered.  What other cases don't have an epilogue?

-- 
H.J.