[PATCH] D93818: [LangRef] Update shufflevector's semantics to return poison if the mask is undef

Juneyoung Lee via Phabricator via llvm-commits llvm-commits at lists.llvm.org
Sun Dec 27 13:50:25 PST 2020


aqjune added a comment.

In D93818#2472270 <https://reviews.llvm.org/D93818#2472270>, @nikic wrote:

> Using `undef` in the shuffle mask to indicate a `poison` result seems pretty confusing to me. I think we should use `poison` as the marker instead. We could allow both undef/poison in input IR, but at least the output IR rendering should use poison (the internal representation is something else anyway, as shuffle masks are no longer Values).

+1, I'll make a patch for this as well.


Repository:
  rG LLVM Github Monorepo

CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D93818/new/

https://reviews.llvm.org/D93818



More information about the llvm-commits mailing list