[gergo_barany]

You are still making things up about the API. If you're actually interested, look at the VectorShuffle class, its docs will tell you all about how illegal indices are handled and how to legalize them. But I doubt that you're actually interested.

It's a pity because you clearly have a lot of knowledge that you could put to use to provide very helpful feedback to implementors of the Vector API. (I'm doing this for the GraalVM compiler.)

[anonymoushn]

I just read the entire documentation for the rearrange method. My apologies for not reading some unrelated docs to find out what rearrange does. It looks like this just makes things worse though? Like you really do have to mask off the high bits of the input, but then you're also paying several instructions for the mapping of out-of-bounds indices to negative values when making the VectorShuffle and then several instructions again to check whether any of them were negative so you can throw an exception from `rearrange`.