Re: [Qemu-devel] [PATCH 2/9] tcg: Add INDEX_op_extract2_{i32,i64}

[Peter Maydell]

On Tue, 26 Mar 2019 at 13:35, Peter Maydell <address@hidden> wrote:
>
> On Thu, 7 Mar 2019 at 14:47, Richard Henderson
> <address@hidden> wrote:
> >
> > This will let backends implement the double-word shift operation.
> >
> > Signed-off-by: Richard Henderson <address@hidden>
> > diff --git a/tcg/README b/tcg/README
> > index 603f4df659..ddabf33017 100644
> > --- a/tcg/README
> > +++ b/tcg/README
> > @@ -343,6 +343,11 @@ at bit 8.  This operation would be equivalent to
> >
> >  (using an arithmetic right shift).
> >
> > +* extract2_i64 dest, t1, t2, pos
> > +
> > +Extract a 64-bit quantity from the concatenation of t2:t1,
> > +beginning at pos.
> > +
>
> I think we should document the valid values of 'pos'.
> My guess is "0 <= pos <= 63".

...also, patch 1 implements "extract2_i64" and "extract2_i32",
but this patch only documents one of those.

thanks
-- PMM