[LLVMdev] loop vectorizer

[Renato Golin]

On 30 October 2013 09:25, Nadav Rotem <nrotem at apple.com> wrote:

> The access pattern to arrays a and b is non-linear.  Unrolled loops are
> usually handled by the SLP-vectorizer.  Are ir0 and ir1 consecutive for all
> values for i ?
>

Based on his list of values, it seems that the induction stride is linear
within each block of 4 iterations, but it's not a clear relationship.

As you say, it should be possible to spot that once the loop is unrolled,
and get the SLP to vectorize if the relationship becomes clear.

Maybe I'm wrong, but this looks like a problem of missed opportunities, not
technically hard to implement.

--renato
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