[PATCH] D47019: [X86] Lowering rotation intrinsics to native IR

[Tomasz Krupa via Phabricator via llvm-commits]

tkrupa added a comment.

Because emitting shifts in IR is more complicated than just adding an shl/lshr node due to those poison values (see https://reviews.llvm.org/D46946) and would create some redundant code. I guess I can use simplifyX86immShift directly instead of emitting a call here.
As for the bug - much more than one instruction gets thrown out of the loop after applying shift lowering patch - I'm leaning to leaving only non-variable intrinsics in this patch and implement variable ones after the generic intrinsic is introduced.


Repository:
  rL LLVM

https://reviews.llvm.org/D47019