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

[Krzysztof Parzyszek via Phabricator via llvm-commits]

kparzysz added a comment.

In https://reviews.llvm.org/D47725#1126768, @efriedma wrote:

> (When I said there was a redundant operation, I was referring to the second SUB.)


Yeah, the first sub came from ROTR->ROTL conversion, so it was actually 5 instructions for the ROTL alone.  I think we should be able to optimize it further on targets where large shift amounts generate 0 (in DAG combiner?).


Repository:
  rL LLVM

https://reviews.llvm.org/D47725