[llvm-commits] Reassociating for vectors

[Andrew Trick]

On May 25, 2012, at 7:38 PM, Hal Finkel wrote:
> This interests me because I also need some procedure for
> reassociating in order to have basic-block vectorization do something
> interesting for reductions. To start, I'd want a+b+c+d+e+f+g+h,
> regardless of the original association, to be transformed into:
> (a+b)+(c+d)+(e+f)+(g+h) or (a+b+c+d)+(e+f+g+h) [the number of groups
> should depend on the target's vector length, and maybe some other
> things as well].
> 
> I'm not sure whether I should try to bake this into Reassociate, or
> refactor Reassociate so that parts of it can be used by BBVectorize, or
> something else. Do you have an opinion?

This sounds to me like something BBVectorize should do only after determining the expression is vectorizable.

-Andy
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.llvm.org/pipermail/llvm-commits/attachments/20120526/ff243ef0/attachment.html>