[PATCH] D62024: [InstCombine] fold shuffles of insert_subvectors

[Eli Friedman via Phabricator via llvm-commits]

efriedma added a comment.

LangRef isn't really appropriate; it's not an issue of correctness.  (All targets support all shuffles; it's just that some of them generate terrible code.)

Maybe doxygen on InstCombiner::visitShuffleVectorInst is okay.  Not sure where else we would put it; maybe CodeGenerator.rst, but that doesn't seem great.


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  https://reviews.llvm.org/D62024/new/

https://reviews.llvm.org/D62024