[PATCH] D79171: [InstCombine] canonicalize bitcast after insertelement into undef

[Craig Topper via Phabricator via llvm-commits]

craig.topper added a comment.

I messed with mmx in this area once and regretted it. See rG5ebbabc1af360756f402203ba7704bb480f279a7 <https://reviews.llvm.org/rG5ebbabc1af360756f402203ba7704bb480f279a7>

Is canonicalizing towards a vector type that wasn't mentioned in the IR the right way to go? Is that cast free for legal types on all targets? I think its potentially scalarized or becomes a load/store to stack temporary for illegal types in the backend.


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  https://reviews.llvm.org/D79171/new/

https://reviews.llvm.org/D79171