[flang-commits] [flang] [flang][NFCI] Stop tracking memory source after a load in a more explicit manner. (PR #126156)

[Joel E. Denny via flang-commits]

================
@@ -600,6 +590,40 @@ AliasAnalysis::Source AliasAnalysis::getSource(mlir::Value v,
             defOp = v.getDefiningOp();
             return;
           }
+
+          // If we are loading a box reference, but following the data,
+          // we gather the attributes of the box to populate the source
+          // and stop tracking.
+          if (auto boxTy = mlir::dyn_cast<fir::BaseBoxType>(ty);
+              boxTy && followingData) {
+
+            if (mlir::isa<fir::PointerType>(boxTy.getEleTy()))
+              attributes.set(Attribute::Pointer);
+
+            auto def = getOriginalDef(op.getMemref());
+            if (auto addrOfOp = def.template getDefiningOp<fir::AddrOfOp>()) {
+              global = addrOfOp.getSymbol();
+
+              if (hasGlobalOpTargetAttr(def, addrOfOp))
+                attributes.set(Attribute::Target);
+
+              type = SourceKind::Global;
+            }
+
+            // TODO: Add support to fir.alloca and fir.allocmem
+            // if (auto allocOp = def.template getDefiningOp<fir::AllocaOp>()) {
+            //   ...
+            // }
+
+            if (isDummyArgument(def)) {
+              defOp = nullptr;
+              v = def;
+            }
+
+            breakFromLoop = true;
+            return;
----------------
jdenny-ornl wrote:

I just noticed that we now return here without setting `type = SourceKind::Indirect` in some cases when we don't have a dummy arg or AddrOfOp.  As a result, some cases that used to be Indirect are now Unknown.  That seems fine for `AliasAnalysis::alias`, whose logic treats them equivalently.  Is this change intentional?

https://github.com/llvm/llvm-project/pull/126156