Species-agnostic shuffle

[Martin Traverso]

Thanks John, that's exactly what I was looking for.

I didn't tell the whole story earlier to keep the example simple, but I
need to be able to swap alternating sequences of 8 bytes due to rearrange()
for LongVector being unusably slow. It's somewhat more involved that a
simple "i ^ 1", but this does the trick:

    VectorShuffle.fromOp(ps, i -> ((i / 8) ^ 1) * 8 + i % 8)

- Martin



On Tue, Jul 9, 2024 at 4:19 PM John Rose <john.r.rose at oracle.com> wrote:

> Maybe VectorShuffle::fromOp will do the trick?
>
> var vs = VectorShuffle.fromOp(ps, i -> i ^ 1);
>
> On 9 Jul 2024, at 9:59, Martin Traverso wrote:
>
> > Hi,
> >
> > I've been experimenting with the Vector API in an attempt to port the
> XXH3
> > hashing algorithm to Java. One of the steps requires rearranging the
> > elements of a vector by swapping adjacent values. I.e., (v0, v1, v2, v3,
> > ...) -> (v1, v0, v3, v2, ...).
>
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