Re: PATCH to add more FALLTHRU markers

[Marek Polacek <polacek@redhat.com>]

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?

	Marek