[PATCH] D70246: [InstCombine] remove identity shuffle simplification for mask with undefs

[Sanjay Patel via Phabricator via llvm-commits]

spatel marked an inline comment as done.
spatel added inline comments.


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Comment at: llvm/lib/Transforms/InstCombine/InstCombineSimplifyDemanded.cpp:1277-1279
+    // If this shuffle does not change the vector length and the elements
+    // demanded by this shuffle are an identity mask, then this shuffle is
+    // unnecessary.
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Note: we could commit this code addition as a preliminary step. It causes some seemingly benign test changes to extractelement index types (i32 vs i64). I have not tracked down where that difference originates.


CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D70246/new/

https://reviews.llvm.org/D70246