Re: PATCH to add more FALLTHRU markers

[Jakub Jelinek <jakub@redhat.com>]

On Thu, Sep 29, 2016 at 06:21:13PM +0200, Marek Polacek wrote:
> On Tue, Sep 27, 2016 at 09:58:20PM +0200, Jakub Jelinek wrote:
> > On Tue, Sep 27, 2016 at 09:29:10PM +0200, Florian Weimer wrote:
> > > Not sure if I read this code correctly, but if we fall through from
> > > V32HImode, and we have TARGET_SSE2 set, we execute this code:
> > > 
> > >       tmp = "p<logic>";
> > >       ssesuffix = TARGET_AVX512VL ? "q" : "";
> > > 
> > > And not gcc_unreachable (), as is probably intended.
> > 
> > It really doesn't matter.
> > The instruction uses
> > (define_mode_iterator VI12_AVX_AVX512F
> >   [ (V64QI "TARGET_AVX512F") (V32QI "TARGET_AVX") V16QI
> >     (V32HI "TARGET_AVX512F") (V16HI "TARGET_AVX") V8HI])
> > iterator (and, after all, ix86_hard_regno_mode_ok should ensure the same),
> > which means V64QI/V32HI will only show up for TARGET_AVX512F, V32QI/V16HI
> > only for TARGET_AVX (which implies TARGET_SSE2), and the slightly
> > nonsensical
> > gcc_assert (TARGET_SSE2 || TARGET_AVX512VL);
> > before the switch (the  || TARGET_AVX512VL is pointless, because
> > TARGET_AVX512VL implies TARGET_SSE2 as well as TARGET_AVX2).
> > So, I'd go perhaps for (untested) following patch, first diff -up, followed
> > by diff -upb:
> 
> Looks good, are you going to test/commit it?  Or should I?

Forgot to test it, will do tomorrow.

	Jakub