[flang-commits] [flang] [Flang][OpenMP] Correct ArrayElements in Reduction Clause (PR #196094)

[Tom Eccles via flang-commits]

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@@ -1592,6 +1592,29 @@ static bool hasDeferredCharacterLength(const Fortran::semantics::Symbol &sym) {
          type->characterTypeSpec().length().isDeferred();
 }
 
+static mlir::Value
+findOverriddenExprValue(const Fortran::lower::ExprToValueMap &map,
+                        const Fortran::lower::SomeExpr &expr) {
+  if (auto match = map.find(&expr); match != map.end())
+    return match->second;
+
+  if (!Fortran::evaluate::IsArrayElement(expr))
+    return {};
+
+  for (auto [key, value] : map) {
+    if (key == llvm::DenseMapInfo<
+                   const Fortran::lower::SomeExpr *>::getEmptyKey() ||
+        key == llvm::DenseMapInfo<
+                   const Fortran::lower::SomeExpr *>::getTombstoneKey())
+      continue;
+    if (Fortran::evaluate::IsArrayElement(*key) &&
+        key->AsFortran() == expr.AsFortran())
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tblah wrote:

Is this defensive programming or did you actually find cases where this caught things? I think if this is needed it would imply that we fundamentally can't trust a map keyed by SomeExpr*

https://github.com/llvm/llvm-project/pull/196094