[PATCH] D102821: [SelectionDAG] Re-calculate scoped AA metadata when merging stores.

[Jeroen Dobbelaere via Phabricator via llvm-commits]

jeroen.dobbelaere added a comment.

Maybe also a testcase using new struct path tbaa would be handy ?



================
Comment at: llvm/lib/CodeGen/SelectionDAG/DAGCombiner.cpp:16892
+    // Merge AA metadata.
+    AAInfo = AAInfo.merge(St->getAAInfo());
+  }
----------------
You are merging aa information of adjacent stores here. For the pure 'struct path tbaa' this should be fine. For the 'new' struct path tbaa, there is a problem, as that one also tracks the offset/size of the the tbaa tag information. For that reason, I think that a (new) 'mergeAdjacent' is better, as that one can throw away the tbaa info (or adapt the offset/size when compatible) when in 'new struct path tbaa' mode.



Repository:
  rG LLVM Github Monorepo

CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D102821/new/

https://reviews.llvm.org/D102821