[PATCH] D28907: [SLP] Fix for PR30787: Failure to beneficially vectorize 'copyable' elements in integer binary ops.

[Simon Pilgrim via Phabricator via llvm-commits]

RKSimon added a comment.

@dtemirbulatov @ABataev I'm not sure how much this will cross over but I'm investigating how to extend the alternate opcode mechanism to work with non-binary instructions. Initially I'm just looking at cast + call operators (e.g. sitofp/uitofp, floor/ceil etc.) but even that requires moderate refactoring of the getEntryCost and vectorizeTree ShuffleVector handling. What I'm not sure of is whether we could extend this idea to accept any partial vectorization and the alternate becomes a pass through - what do you think?

If not there is scope to further simplify this patch, for instance @spatel's work in InstCombine for PR37806 should mean that you can rely on InstCombine to perform much of the work in getDefaultConstantForOpcode etc. and all SLP needs to do is create a "passthrough" SK_Select shuffle stage.


https://reviews.llvm.org/D28907