On Fri, 19 Jul 2019 at 12:45, Paolo Bonzini <pbonz...@redhat.com> wrote:
>
> On 19/07/19 13:23, Philippe Mathieu-Daudé wrote:
> > Reported by GCC9 when building with CFLAG -Wimplicit-fallthrough=2:
> >
> > CC target/i386/translate.o
> > target/i386/translate.c: In function ‘gen_shiftd_rm_T1’:
> > target/i386/translate.c:1785:12: error: this statement may fall through
> > [-Werror=implicit-fallthrough=]
> > 1785 | if (is_right) {
> > | ^
> > target/i386/translate.c:1810:5: note: here
> > 1810 | default:
> > | ^~~~~~~
> > cc1: all warnings being treated as errors
> >
> > Fixes: f437d0a3c24
> > Signed-off-by: Philippe Mathieu-Daudé <phi...@redhat.com>
> > ---
> > target/i386/translate.c | 2 +-
> > 1 file changed, 1 insertion(+), 1 deletion(-)
> >
> > diff --git a/target/i386/translate.c b/target/i386/translate.c
> > index 03150a86e2..4b2b5937ca 100644
> > --- a/target/i386/translate.c
> > +++ b/target/i386/translate.c
> > @@ -1805,8 +1805,8 @@ static void gen_shiftd_rm_T1(DisasContext *s,
> > TCGMemOp ot, int op1,
> > tcg_gen_shri_i64(s->tmp0, s->tmp0, 32);
> > tcg_gen_shri_i64(s->T0, s->T0, 32);
> > }
> > - break;
> > #endif
> > + break;
> > default:
> > tcg_gen_subi_tl(s->tmp0, count, 1);
> > if (is_right) {
> >
>
> I haven't looked closely at the code but I would guess that the
> fallthrough is intended, because the default label has an "ot == MO_16"
> condition.
Yeah, this code is really weird -- if TARGET_X86_64 then
MO_16 falls through into MO_32, but if only i386 then
MO_16 falls through into the default case ?!?
thanks
-- PMM
