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

[Peter Maydell]

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".

thanks
-- PMM