[PATCH] D125378: [Attribute] Introduce shuffle attribute to be used for __shfl_sync like cross-lane APIs

Aaron Ballman via Phabricator via llvm-commits llvm-commits at lists.llvm.org
Wed May 11 08:38:51 PDT 2022


aaron.ballman added inline comments.


================
Comment at: clang/include/clang/Basic/AttrDocs.td:1323-1344
+def ShuffleDocs : Documentation {
+  let Category = DocCatFunction;
+  let Content = [{
+The ``shuffle`` attribute can be placed on a function declaration. It indicates
+that the call instructions of a function with this attribute can take undef
+arguments and is still valid.
+
----------------
This sounds highly specific to those language standards and like an expert-only feature that's going to be a footgun for everyone else. Is there a way these special functions can be identified at codegen time (or within the backend) so that we don't have to expose an attribute for this?


CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D125378/new/

https://reviews.llvm.org/D125378



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