Re: [Qemu-devel] [PATCH v1 02/14] target-ppc: Add xxinsertw instruction

[David Gibson]

On Fri, Jan 06, 2017 at 01:58:19PM +0530, Nikunj A Dadhania wrote:
> David Gibson <address@hidden> writes:
> 
> > [ Unknown signature status ]
> > On Fri, Jan 06, 2017 at 11:44:44AM +0530, Nikunj A Dadhania wrote:
> >> xxinsertw: VSX Vector Insert Word
> >> 
> >> Signed-off-by: Nikunj A Dadhania <address@hidden>
> >
> > The comments I had about out of bounds shifts don't seem to have been
> > addressed here.
> 
> Bounds are addressed inside the for condition:
> 
> #if defined(HOST_WORDS_BIGENDIAN)
>     ins_index = index;
>     for (i = 0; i < es && ins_index < 16; i++, ins_index++) {
>                           ^^^^^^^^^^^^^^
>         xt.u8[ins_index] = xb.u8[8 - es + i];
>     }
> #else
>     ins_index = 15 - index;
>     for (i = es - 1; i >= 0 && ins_index >= 0; i--, ins_index--) {
>                                ^^^^^^^^^^^^^^
>         xt.u8[ins_index] = xb.u8[8 + i];
>     }
> #endif
> 
> That way ins_index will be within 0 - 15. Let me know if I have missed
> something.

Oh, yes, I missed that.  Sorry.
-- 
David Gibson                    | I'll have my music baroque, and my code
david AT gibson.dropbear.id.au  | minimalist, thank you.  NOT _the_ _other_
                                | _way_ _around_!
http://www.ozlabs.org/~dgibson

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