[flang-commits] [flang] [flang] Follow memory source through more operations (PR #66713)

[Tom Eccles via flang-commits]

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@@ -80,12 +95,27 @@ AliasResult AliasAnalysis::alias(Value lhs, Value rhs) {
              llvm::dbgs() << "  rhsSrc: " << rhsSrc << "\n";
              llvm::dbgs() << "\n";);
 
+  // SourceKind::Unknown is set for the addresses wrapped in a global boxes.
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tblah wrote:

Are there not other situations where we get `SourceKind::Unknown`? For example, when encountering an unsupported operation.

I think it would be better to keep `SourceKind::Unknown` as a state for "we don't know what's going on, conservatively assume it aliases with everything", then set these global pointers to a new state representing a "known unknown" - we don't know much about them but in a controlled way.

https://github.com/llvm/llvm-project/pull/66713