[PATCH] D47725: [SelectionDAG] Provide default expansion for rotates

[Eli Friedman via Phabricator via llvm-commits]

efriedma added a comment.

Hmm... yes, I guess the AND isn't necessary if the shift produces either zero or the input, which is true for every target I can think of.  But `(SHL x, 32)` is defined to produce undef for a 32-bit input, not some target-specific result, so you can't depend on that.  Might make sense to add a dedicated target-independent opcode to represent it.


Repository:
  rL LLVM

https://reviews.llvm.org/D47725