[X86][SSE] Lower shuffles to permute(unpack(x,y)) (PR31151)
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Authored by RKSimon on Sep 13 2018, 9:13 AM.

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Summary

Attempt to lower a shuffle as an unpack of elements from two inputs followed by a single-input (wider) permutation.

As long as the permutation is wider this is a win - there may be some circumstances where same size permutations would also be useful but I've left that for future work.

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rL LLVM
RKSimon created this revision.Sep 13 2018, 9:13 AM

Looks alright to me, and cleaner than what I suggested in bug 31151. And the test results look great too.

Any more comments?

This revision is now accepted and ready to land.Sep 14 2018, 10:17 AM
This revision was automatically updated to reflect the committed changes.