[PATCH] D91833: [SelectionDAG] Avoid aliasing analysis if the object size is unknown.

[Hsiangkai Wang via Phabricator via llvm-commits]

HsiangKai added inline comments.


================
Comment at: llvm/lib/CodeGen/SelectionDAG/SelectionDAGAddressAnalysis.cpp:103
+    // vector objects on the stack.
+    if (*NumBytes0 == static_cast<int64_t>(MemoryLocation::UnknownSize) ||
+        *NumBytes1 == static_cast<int64_t>(MemoryLocation::UnknownSize))
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niravd wrote:
> This is too aggressive. We can still determine that a two addresses are non-aliasing even if one is unknown size. (e.g. FrameIndex vs. Global)
The checking is under the condition that BasePtr0.equalBaseIndex(BasePtr1, ...) equals true. It would not be the case you considered.


Repository:
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CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D91833/new/

https://reviews.llvm.org/D91833