[PATCH] D75062: [VectorCombine] make cost calc consistent for binops and cmps

[Sanjay Patel via Phabricator via llvm-commits]

spatel added a comment.

For reference, a motivating case for VectorCombine that I'm hoping to build up to (not there yet because we need a shuffle):
https://bugs.llvm.org/show_bug.cgi?id=42633

If we make the cost calc conservative, then we probably forego creating a vector op on that example for some targets even though it's a likely win.

Another possibility is that targets will need to have more complex cost modeling for extract/insert (D74976 <https://reviews.llvm.org/D74976>) - but that's probably not enough by itself to get all of the missed vectorizations we've seen.


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  https://reviews.llvm.org/D75062/new/

https://reviews.llvm.org/D75062