[LLVMdev] Predicated Vector Operations

[Eric Christopher]

On Wed, May 8, 2013 at 3:31 PM, Nadav Rotem <nrotem at apple.com> wrote:
>
> On May 8, 2013, at 1:59 PM, Eric Christopher <echristo at gmail.com> wrote:
>
> I can almost see that, but how is the intrinsic any different from a
> conservative width for stores/loads where they're not handled by an
> optimization pass? I'm assuming I'm missing something here.
>
> -eric
>
>
> I don't understand what you mean by "conservative width".

Thinking that a masked store is conservatively a store of the full
width of the store right?

But Jim pointed out that anything merging loads would then need to
merge the masks otherwise even if selection would work otherwise, any
pass that merges loads would need to learn how to deal with masks. Not
likely a deal killer since I don't think there are a lot of them, but
it does explain why it's more work than having them pass through.

-eric