[flang] Fix lowering of host associated cray pointee symbols (#86121)

Cray pointee symbols can be host associated from a module or host procedure while the related cray pointer is not explicitly associated. This caused the "not yet implemented: lowering symbol to HLFIR" to fire when lowering a reference to the cray pointee and fetching the cray pointer. This patch: - Ensures cray pointers are always instantiated when instantiating a cray pointee. - Fix internal procedure lowering to deal with cray pointee host association like it does for pointers (the lowering strategy for cray pointee is to create a pointer that is updated with the cray pointer value before being fetched). This should fix the bug reported in #85420.
llvm · Mar 22, 2024 · de7a50f · de7a50f
1 parent 465ea0b
commit de7a50f
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Showing 11 changed files with 176 additions and 53 deletions.
diff --git a/flang/include/flang/Lower/ConvertVariable.h b/flang/include/flang/Lower/ConvertVariable.h
@@ -161,9 +161,9 @@ void genDeclareSymbol(Fortran::lower::AbstractConverter &converter,
                           fir::FortranVariableFlagsEnum::None,
                       bool force = false);
 
-/// For the given Cray pointee symbol return the corresponding
-/// Cray pointer symbol. Assert if the pointer symbol cannot be found.
-Fortran::semantics::SymbolRef getCrayPointer(Fortran::semantics::SymbolRef sym);
+/// Given the Fortran type of a Cray pointee, return the fir.box type used to
+/// track the cray pointee as Fortran pointer.
+mlir::Type getCrayPointeeBoxType(mlir::Type);
 
 } // namespace lower
 } // namespace Fortran

diff --git a/flang/include/flang/Semantics/tools.h b/flang/include/flang/Semantics/tools.h
@@ -282,6 +282,9 @@ const Symbol *FindExternallyVisibleObject(
 // specific procedure of the same name, return it instead.
 const Symbol &BypassGeneric(const Symbol &);
 
+// Given a cray pointee symbol, returns the related cray pointer symbol.
+const Symbol &GetCrayPointer(const Symbol &crayPointee);
+
 using SomeExpr = evaluate::Expr<evaluate::SomeType>;
 
 bool ExprHasTypeCategory(

diff --git a/flang/lib/Lower/Bridge.cpp b/flang/lib/Lower/Bridge.cpp
@@ -3995,11 +3995,12 @@ class FirConverter : public Fortran::lower::AbstractConverter {
                     sym->Rank() == 0) {
                   // get the corresponding Cray pointer
 
-                  auto ptrSym = Fortran::lower::getCrayPointer(*sym);
+                  const Fortran::semantics::Symbol &ptrSym =
+                      Fortran::semantics::GetCrayPointer(*sym);
                   fir::ExtendedValue ptr =
                       getSymbolExtendedValue(ptrSym, nullptr);
                   mlir::Value ptrVal = fir::getBase(ptr);
-                  mlir::Type ptrTy = genType(*ptrSym);
+                  mlir::Type ptrTy = genType(ptrSym);
 
                   fir::ExtendedValue pte =
                       getSymbolExtendedValue(*sym, nullptr);

diff --git a/flang/lib/Lower/ConvertExpr.cpp b/flang/lib/Lower/ConvertExpr.cpp
@@ -862,7 +862,8 @@ class ScalarExprLowering {
                                          addr);
         } else if (sym->test(Fortran::semantics::Symbol::Flag::CrayPointee)) {
           // get the corresponding Cray pointer
-          auto ptrSym = Fortran::lower::getCrayPointer(sym);
+          Fortran::semantics::SymbolRef ptrSym{
+              Fortran::semantics::GetCrayPointer(sym)};
           ExtValue ptr = gen(ptrSym);
           mlir::Value ptrVal = fir::getBase(ptr);
           mlir::Type ptrTy = converter.genType(*ptrSym);
@@ -1537,8 +1538,8 @@ class ScalarExprLowering {
     auto baseSym = getFirstSym(aref);
     if (baseSym.test(Fortran::semantics::Symbol::Flag::CrayPointee)) {
       // get the corresponding Cray pointer
-      auto ptrSym = Fortran::lower::getCrayPointer(baseSym);
-
+      Fortran::semantics::SymbolRef ptrSym{
+          Fortran::semantics::GetCrayPointer(baseSym)};
       fir::ExtendedValue ptr = gen(ptrSym);
       mlir::Value ptrVal = fir::getBase(ptr);
       mlir::Type ptrTy = ptrVal.getType();
@@ -6946,7 +6947,8 @@ class ArrayExprLowering {
                             ComponentPath &components) {
     mlir::Value ptrVal = nullptr;
     if (x.test(Fortran::semantics::Symbol::Flag::CrayPointee)) {
-      auto ptrSym = Fortran::lower::getCrayPointer(x);
+      Fortran::semantics::SymbolRef ptrSym{
+          Fortran::semantics::GetCrayPointer(x)};
       ExtValue ptr = converter.getSymbolExtendedValue(ptrSym);
       ptrVal = fir::getBase(ptr);
     }

diff --git a/flang/lib/Lower/ConvertExprToHLFIR.cpp b/flang/lib/Lower/ConvertExprToHLFIR.cpp
@@ -284,7 +284,7 @@ class HlfirDesignatorBuilder {
         // value of the Cray pointer variable.
         fir::FirOpBuilder &builder = getBuilder();
         fir::FortranVariableOpInterface ptrVar =
-            gen(Fortran::lower::getCrayPointer(symbolRef));
+            gen(Fortran::semantics::GetCrayPointer(symbolRef));
         mlir::Value ptrAddr = ptrVar.getBase();
 
         // Reinterpret the reference to a Cray pointer so that
@@ -306,9 +306,16 @@ class HlfirDesignatorBuilder {
       }
       return *varDef;
     }
+    llvm::errs() << *symbolRef << "\n";
     TODO(getLoc(), "lowering symbol to HLFIR");
   }
 
+  fir::FortranVariableOpInterface
+  gen(const Fortran::semantics::Symbol &symbol) {
+    Fortran::evaluate::SymbolRef symref{symbol};
+    return gen(symref);
+  }
+
   fir::FortranVariableOpInterface
   gen(const Fortran::evaluate::Component &component) {
     if (Fortran::semantics::IsAllocatableOrPointer(component.GetLastSymbol()))

diff --git a/flang/lib/Lower/ConvertVariable.cpp b/flang/lib/Lower/ConvertVariable.cpp
@@ -1554,6 +1554,11 @@ fir::FortranVariableFlagsAttr Fortran::lower::translateSymbolAttributes(
     mlir::MLIRContext *mlirContext, const Fortran::semantics::Symbol &sym,
     fir::FortranVariableFlagsEnum extraFlags) {
   fir::FortranVariableFlagsEnum flags = extraFlags;
+  if (sym.test(Fortran::semantics::Symbol::Flag::CrayPointee)) {
+    // CrayPointee are represented as pointers.
+    flags = flags | fir::FortranVariableFlagsEnum::pointer;
+    return fir::FortranVariableFlagsAttr::get(mlirContext, flags);
+  }
   const auto &attrs = sym.attrs();
   if (attrs.test(Fortran::semantics::Attr::ALLOCATABLE))
     flags = flags | fir::FortranVariableFlagsEnum::allocatable;
@@ -1615,8 +1620,6 @@ static void genDeclareSymbol(Fortran::lower::AbstractConverter &converter,
       (!Fortran::semantics::IsProcedure(sym) ||
        Fortran::semantics::IsPointer(sym)) &&
       !sym.detailsIf<Fortran::semantics::CommonBlockDetails>()) {
-    bool isCrayPointee =
-        sym.test(Fortran::semantics::Symbol::Flag::CrayPointee);
     fir::FirOpBuilder &builder = converter.getFirOpBuilder();
     const mlir::Location loc = genLocation(converter, sym);
     mlir::Value shapeOrShift;
@@ -1636,31 +1639,21 @@ static void genDeclareSymbol(Fortran::lower::AbstractConverter &converter,
         Fortran::lower::translateSymbolCUDADataAttribute(builder.getContext(),
                                                          sym);
 
-    if (isCrayPointee) {
-      mlir::Type baseType =
-          hlfir::getFortranElementOrSequenceType(base.getType());
-      if (auto seqType = mlir::dyn_cast<fir::SequenceType>(baseType)) {
-        // The pointer box's sequence type must be with unknown shape.
-        llvm::SmallVector<int64_t> shape(seqType.getDimension(),
-                                         fir::SequenceType::getUnknownExtent());
-        baseType = fir::SequenceType::get(shape, seqType.getEleTy());
-      }
-      fir::BoxType ptrBoxType =
-          fir::BoxType::get(fir::PointerType::get(baseType));
+    if (sym.test(Fortran::semantics::Symbol::Flag::CrayPointee)) {
+      mlir::Type ptrBoxType =
+          Fortran::lower::getCrayPointeeBoxType(base.getType());
       mlir::Value boxAlloc = builder.createTemporary(loc, ptrBoxType);
 
       // Declare a local pointer variable.
-      attributes = fir::FortranVariableFlagsAttr::get(
-          builder.getContext(), fir::FortranVariableFlagsEnum::pointer);
       auto newBase = builder.create<hlfir::DeclareOp>(
           loc, boxAlloc, name, /*shape=*/nullptr, lenParams, attributes);
-      mlir::Value nullAddr =
-          builder.createNullConstant(loc, ptrBoxType.getEleTy());
+      mlir::Value nullAddr = builder.createNullConstant(
+          loc, llvm::cast<fir::BaseBoxType>(ptrBoxType).getEleTy());
 
       // If the element type is known-length character, then
       // EmboxOp does not need the length parameters.
       if (auto charType = mlir::dyn_cast<fir::CharacterType>(
-              fir::unwrapSequenceType(baseType)))
+              hlfir::getFortranElementType(base.getType())))
         if (!charType.hasDynamicLen())
           lenParams.clear();
 
@@ -2346,16 +2339,13 @@ void Fortran::lower::createRuntimeTypeInfoGlobal(
   defineGlobal(converter, var, globalName, linkage);
 }
 
-Fortran::semantics::SymbolRef
-Fortran::lower::getCrayPointer(Fortran::semantics::SymbolRef sym) {
-  assert(!sym->GetUltimate().owner().crayPointers().empty() &&
-         "empty Cray pointer/pointee map");
-  for (const auto &[pointee, pointer] :
-       sym->GetUltimate().owner().crayPointers()) {
-    if (pointee == sym->name()) {
-      Fortran::semantics::SymbolRef v{pointer.get()};
-      return v;
-    }
+mlir::Type Fortran::lower::getCrayPointeeBoxType(mlir::Type fortranType) {
+  mlir::Type baseType = hlfir::getFortranElementOrSequenceType(fortranType);
+  if (auto seqType = mlir::dyn_cast<fir::SequenceType>(baseType)) {
+    // The pointer box's sequence type must be with unknown shape.
+    llvm::SmallVector<int64_t> shape(seqType.getDimension(),
+                                     fir::SequenceType::getUnknownExtent());
+    baseType = fir::SequenceType::get(shape, seqType.getEleTy());
   }
-  llvm_unreachable("corresponding Cray pointer cannot be found");
+  return fir::BoxType::get(fir::PointerType::get(baseType));
 }
diff --git a/flang/lib/Lower/HostAssociations.cpp b/flang/lib/Lower/HostAssociations.cpp
@@ -315,7 +315,11 @@ class CapturedAllocatableAndPointer
 public:
   static mlir::Type getType(Fortran::lower::AbstractConverter &converter,
                             const Fortran::semantics::Symbol &sym) {
-    return fir::ReferenceType::get(converter.genType(sym));
+    mlir::Type baseType = converter.genType(sym);
+    if (sym.GetUltimate().test(Fortran::semantics::Symbol::Flag::CrayPointee))
+      return fir::ReferenceType::get(
+          Fortran::lower::getCrayPointeeBoxType(baseType));
+    return fir::ReferenceType::get(baseType);
   }
   static void instantiateHostTuple(const InstantiateHostTuple &args,
                                    Fortran::lower::AbstractConverter &converter,
@@ -507,7 +511,8 @@ walkCaptureCategories(T visitor, Fortran::lower::AbstractConverter &converter,
   if (Fortran::semantics::IsProcedure(sym))
     return CapturedProcedure::visit(visitor, converter, sym, ba);
   ba.analyze(sym);
-  if (Fortran::semantics::IsAllocatableOrPointer(sym))
+  if (Fortran::semantics::IsAllocatableOrPointer(sym) ||
+      sym.GetUltimate().test(Fortran::semantics::Symbol::Flag::CrayPointee))
     return CapturedAllocatableAndPointer::visit(visitor, converter, sym, ba);
   if (ba.isArray())
     return CapturedArrays::visit(visitor, converter, sym, ba);

diff --git a/flang/lib/Lower/PFTBuilder.cpp b/flang/lib/Lower/PFTBuilder.cpp
@@ -1594,6 +1594,11 @@ struct SymbolDependenceAnalysis {
           if (!s->has<semantics::DerivedTypeDetails>())
             depth = std::max(analyze(s) + 1, depth);
     }
+
+    // Make sure cray pointer is instantiated even if it is not visible.
+    if (ultimate.test(Fortran::semantics::Symbol::Flag::CrayPointee))
+      depth = std::max(
+          analyze(Fortran::semantics::GetCrayPointer(ultimate)) + 1, depth);
     adjustSize(depth + 1);
     bool global = lower::symbolIsGlobal(sym);
     layeredVarList[depth].emplace_back(sym, global, depth);
@@ -2002,6 +2007,10 @@ struct SymbolVisitor {
         }
       }
     }
+    // - CrayPointer needs to be available whenever a CrayPointee is used.
+    if (symbol.GetUltimate().test(
+            Fortran::semantics::Symbol::Flag::CrayPointee))
+      visitSymbol(Fortran::semantics::GetCrayPointer(symbol));
   }
 
   template <typename A>

diff --git a/flang/lib/Semantics/tools.cpp b/flang/lib/Semantics/tools.cpp
@@ -403,6 +403,18 @@ const Symbol &BypassGeneric(const Symbol &symbol) {
   return symbol;
 }
 
+const Symbol &GetCrayPointer(const Symbol &crayPointee) {
+  const Symbol *found{nullptr};
+  for (const auto &[pointee, pointer] :
+      crayPointee.GetUltimate().owner().crayPointers()) {
+    if (pointee == crayPointee.name()) {
+      found = &pointer.get();
+      break;
+    }
+  }
+  return DEREF(found);
+}
+
 bool ExprHasTypeCategory(
     const SomeExpr &expr, const common::TypeCategory &type) {
   auto dynamicType{expr.GetType()};