[flang] [NFCI] Using getSource instead of getOriginalDef (#128984)

As discussed in past MRs, this change removes the use of getOriginalDef
to use getSource instead to gather data from an indirection.

Author: Renaud-K

flang/lib/Optimizer/Analysis/AliasAnalysis.cpp

@@ -51,40 +51,6 @@ static bool hasGlobalOpTargetAttr(mlir::Value v, fir::AddrOfOp op) {
       v, fir::GlobalOp::getTargetAttrName(globalOpName));
 }
 
-static mlir::Value
-getOriginalDef(mlir::Value v,
-               fir::AliasAnalysis::Source::Attributes &attributes,
-               bool &isCapturedInInternalProcedure, bool &approximateSource) {
-  mlir::Operation *defOp;
-  bool breakFromLoop = false;
-  while (!breakFromLoop && (defOp = v.getDefiningOp())) {
-    mlir::Type ty = defOp->getResultTypes()[0];
-    llvm::TypeSwitch<Operation *>(defOp)
-        .Case<fir::ConvertOp>([&](fir::ConvertOp op) { v = op.getValue(); })
-        .Case<fir::DeclareOp, hlfir::DeclareOp>([&](auto op) {
-          v = op.getMemref();
-          auto varIf = llvm::cast<fir::FortranVariableOpInterface>(defOp);
-          attributes |= getAttrsFromVariable(varIf);
-          isCapturedInInternalProcedure |=
-              varIf.isCapturedInInternalProcedure();
-        })
-        .Case<fir::CoordinateOp>([&](auto op) {
-          if (fir::AliasAnalysis::isPointerReference(ty))
-            attributes.set(fir::AliasAnalysis::Attribute::Pointer);
-          v = op->getOperand(0);
-          approximateSource = true;
-        })
-        .Case<hlfir::DesignateOp>([&](hlfir::DesignateOp op) {
-          auto varIf = llvm::cast<fir::FortranVariableOpInterface>(defOp);
-          attributes |= getAttrsFromVariable(varIf);
-          v = op.getMemref();
-          approximateSource = true;
-        })
-        .Default([&](auto op) { breakFromLoop = true; });
-  }
-  return v;
-}
-
 static bool isEvaluateInMemoryBlockArg(mlir::Value v) {
   if (auto evalInMem = llvm::dyn_cast_or_null<hlfir::EvaluateInMemoryOp>(
           v.getParentRegion()->getParentOp()))
@@ -621,38 +587,34 @@ AliasAnalysis::Source AliasAnalysis::getSource(mlir::Value v,
             if (mlir::isa<fir::PointerType>(boxTy.getEleTy()))
               attributes.set(Attribute::Pointer);
 
-            auto def = getOriginalDef(op.getMemref(), attributes,
-                                      isCapturedInInternalProcedure,
-                                      approximateSource);
-            if (auto addrOfOp = def.template getDefiningOp<fir::AddrOfOp>()) {
-              global = addrOfOp.getSymbol();
-
-              if (hasGlobalOpTargetAttr(def, addrOfOp))
-                attributes.set(Attribute::Target);
+            auto boxSrc = getSource(op.getMemref());
+            attributes |= boxSrc.attributes;
+            approximateSource |= boxSrc.approximateSource;
+            isCapturedInInternalProcedure |=
+                boxSrc.isCapturedInInternalProcedure;
 
+            global = llvm::dyn_cast<mlir::SymbolRefAttr>(boxSrc.origin.u);
+            if (global) {
               type = SourceKind::Global;
-            }
-            // TODO: Add support to fir.allocmem
-            else if (auto allocOp =
-                         def.template getDefiningOp<fir::AllocaOp>()) {
-              v = def;
-              defOp = v.getDefiningOp();
-              type = SourceKind::Allocate;
-            } else if (isDummyArgument(def)) {
-              defOp = nullptr;
-              v = def;
             } else {
-              type = SourceKind::Indirect;
+              auto def = llvm::cast<mlir::Value>(boxSrc.origin.u);
+              // TODO: Add support to fir.allocmem
+              if (auto allocOp = def.template getDefiningOp<fir::AllocaOp>()) {
+                v = def;
+                defOp = v.getDefiningOp();
+                type = SourceKind::Allocate;
+              } else if (isDummyArgument(def)) {
+                defOp = nullptr;
+                v = def;
+              } else {
+                type = SourceKind::Indirect;
+              }
             }
-            // TODO: This assignment is redundant but somehow works around an
-            // apparent MSVC bug reporting "undeclared identifier" at the next
-            // "breakFromLoop = true;".  See
-            // <https://github.com/llvm/llvm-project/pull/127845#issuecomment-2669829610>.
             breakFromLoop = true;
-          } else {
-            // No further tracking for addresses loaded from memory for now.
-            type = SourceKind::Indirect;
+            return;
           }
+          // No further tracking for addresses loaded from memory for now.
+          type = SourceKind::Indirect;
           breakFromLoop = true;
         })
         .Case<fir::AddrOfOp>([&](auto op) {

flang/test/Analysis/AliasAnalysis/source-kind.fir

@@ -0,0 +1,25 @@
+// RUN: fir-opt %s -pass-pipeline='builtin.module(func.func(test-fir-alias-analysis))' -debug-only=fir-alias-analysis 2>&1 | FileCheck %s
+
+// CHECK-LABEL: Testing : "_QFPtest"
+
+// Checking that the source kind of a load of a load is SourceKind::Indirect
+// CHECK: {test.ptr = "load_load"}
+// CHECK-NEXT: SourceKind: Indirect
+
+// Checking that the source kind of a load of an arg is SourceKind::Argument
+// CHECK: {test.ptr = "load_arg"}
+// CHECK-NEXT: SourceKind: Argument
+
+func.func @_QFPtest(%arg0: !fir.ref<!fir.box<!fir.ptr<f32>>> ) attributes {test.ptr = "func"} {
+  
+  %0 = fir.alloca !fir.llvm_ptr<!fir.box<!fir.ptr<f32>>>
+  %1 = fir.convert %arg0 : (!fir.ref<!fir.box<!fir.ptr<f32>>>) -> !fir.llvm_ptr<!fir.box<!fir.ptr<f32>>>
+  fir.store %1 to %0 : !fir.ref<!fir.llvm_ptr<!fir.box<!fir.ptr<f32>>>>
+  %2 = fir.load %0 : !fir.ref<!fir.llvm_ptr<!fir.box<!fir.ptr<f32>>>>
+  %3 = fir.convert %2 : (!fir.llvm_ptr<!fir.box<!fir.ptr<f32>>>) -> !fir.ref<!fir.box<!fir.ptr<f32>>>
+  %15 = fir.load %3 : !fir.ref<!fir.box<!fir.ptr<f32>>>
+  %16 = fir.box_addr %15 {test.ptr = "load_load"} : (!fir.box<!fir.ptr<f32>>) -> !fir.ptr<f32>
+  %17 = fir.load %arg0 : !fir.ref<!fir.box<!fir.ptr<f32>>>
+  %18 = fir.box_addr %17 {test.ptr = "load_arg"} : (!fir.box<!fir.ptr<f32>>) -> !fir.ptr<f32>
+  return
+}