[flang][openacc] Support array slices when creating firstprivate recipe

[clementval]

Summary

The return type of the recipe must match the array slice provided by
the user. This patch enhance the recipe creation to take into account
the constant slices.

Depends on D154657

[razvanlupusoru]

Awesome work. Looks great!

flang/lib/Lower/OpenACC.cpp

for (const auto &accObject : objectList.v) {
     llvm::SmallVector<mlir::Value> bounds;
     std::stringstream asFortran;
     mlir::Location operandLocation = genOperandLocation(converter, accObject);
     mlir::Value baseAddr = gatherDataOperandAddrAndBounds(
         converter, builder, semanticsContext, stmtCtx, accObject,
         operandLocation, asFortran, bounds);
 
     RecipeOp recipe;
-    if constexpr (std::is_same_v<RecipeOp, mlir::acc::PrivateRecipeOp>) {
-      mlir::Type retTy = getTypeFromBounds(bounds, baseAddr.getType());
+    if constexpr (std::is_same_v<RecipeOp, mlir::acc::PrivateRecipeOp>) {
       std::string recipeName =
           fir::getTypeAsString(retTy, converter.getKindMap(), "privatization");
       recipe = Fortran::lower::createOrGetPrivateRecipe(builder, recipeName,
                                                         operandLocation, retTy);
       auto op = createDataEntryOp<mlir::acc::PrivateOp>(
           builder, operandLocation, baseAddr, asFortran, bounds, true,
           mlir::acc::DataClause::acc_private, retTy);
       dataOperands.push_back(op.getAccPtr());
     } else {
       std::string recipeName = fir::getTypeAsString(
-          baseAddr.getType(), converter.getKindMap(), "firstprivatization");
+          retTy, converter.getKindMap(), "firstprivatization");
       recipe = Fortran::lower::createOrGetFirstprivateRecipe(
-          builder, recipeName, operandLocation, baseAddr.getType());
+          builder, recipeName, operandLocation, retTy);
       auto op = createDataEntryOp<mlir::acc::FirstprivateOp>(
           builder, operandLocation, baseAddr, asFortran, bounds, true,
-          mlir::acc::DataClause::acc_firstprivate, baseAddr.getType());
+          mlir::acc::DataClause::acc_firstprivate, retTy);
       dataOperands.push_back(op.getAccPtr());
     }
     privatizations.push_back(mlir::SymbolRefAttr::get(
         builder.getContext(), recipe.getSymName().str()));
   }
 }
 
 /// Return the corresponding enum value for the mlir::acc::ReductionOperator

flang/test/Lower/OpenACC/acc-private.f90

 ! This test checks lowering of OpenACC loop directive.
 
 ! RUN: bbc -fopenacc -emit-fir %s -o - | FileCheck %s
 
+! CHECK-LABEL: acc.firstprivate.recipe @firstprivatization_ref_50xf32 : !fir.ref<!fir.array<50xf32>> init {
+! CHECK: ^bb0(%{{.*}}: !fir.ref<!fir.array<50xf32>>):
+! CHECK:   %[[ALLOCA:.*]] = fir.alloca !fir.array<50xf32>
+! CHECK:   acc.yield %[[ALLOCA]] : !fir.ref<!fir.array<50xf32>>
+! CHECK: } copy {
+! CHECK: ^bb0(%[[SRC:.*]]: !fir.ref<!fir.array<50xf32>>, %[[DST:.*]]: !fir.ref<!fir.array<50xf32>>):
+! CHECK:   %[[LB0:.*]] = arith.constant 0 : index
+! CHECK:   %[[UB0:.*]] = arith.constant 49 : index
+! CHECK:   %[[STEP0:.*]] = arith.constant 1 : index
+! CHECK:   fir.do_loop %[[IV0:.*]] = %[[LB0]] to %[[UB0]] step %[[STEP0]] {
+! CHECK:     %[[COORD0:.*]] = fir.coordinate_of %[[SRC]], %[[IV0]] : (!fir.ref<!fir.array<50xf32>>, index) -> !fir.ref<f32>
+! CHECK:     %[[COORD1:.*]] = fir.coordinate_of %[[DST]], %[[IV0]] : (!fir.ref<!fir.array<50xf32>>, index) -> !fir.ref<f32>
+! CHECK:     %[[VALUE:.*]] = fir.load %[[COORD0]] : !fir.ref<f32>
+! CHECK:     fir.store %[[VALUE]] to %[[COORD1]] : !fir.ref<f32>
+! CHECK:   }
+! CHECK:   acc.terminator
+! CHECK: }
+
 ! CHECK-LABEL: acc.firstprivate.recipe @firstprivatization_ref_100xf32 : !fir.ref<!fir.array<100xf32>> init {
 ! CHECK: ^bb0(%{{.*}}: !fir.ref<!fir.array<100xf32>>):
 ! CHECK:   %[[ALLOCA:.*]] = fir.alloca !fir.array<100xf32>
 ! CHECK:   acc.yield %[[ALLOCA]] : !fir.ref<!fir.array<100xf32>>
 ! CHECK: } copy {
 ! CHECK: ^bb0(%[[SRC:.*]]: !fir.ref<!fir.array<100xf32>>, %[[DST:.*]]: !fir.ref<!fir.array<100xf32>>):
 ! CHECK:   %[[LB0:.*]] = arith.constant 0 : index
 ! CHECK:   %[[UB0:.*]] = arith.constant 99 : index
! CHECK: acc.yield
   END DO
 
 ! CHECK: %[[C1:.*]] = arith.constant 1 : index
 ! CHECK: %[[LB:.*]] = arith.constant 0 : index
 ! CHECK: %[[UB:.*]] = arith.subi %{{.*}}, %[[C1]] : index
 ! CHECK: %[[BOUND:.*]] = acc.bounds lowerbound(%[[LB]] : index) upperbound(%[[UB]] : index) stride(%[[C1]] : index) startIdx(%[[C1]] : index)
 ! CHECK: %[[FP_B:.*]] = acc.firstprivate varPtr(%[[B]] : !fir.ref<!fir.array<100xf32>>) bounds(%[[BOUND]]) -> !fir.ref<!fir.array<100xf32>> {name = "b"}
 ! CHECK: acc.parallel firstprivate(@firstprivatization_ref_100xf32 -> %[[FP_B]] : !fir.ref<!fir.array<100xf32>>)
+! CHECK: acc.yield
+
+  !$acc parallel loop firstprivate(b(51:100))
+  DO i = 1, n
+    c = i
+    a(i) = b(i) + c
+  END DO
+
+! CHECK: %[[C1:.*]] = arith.constant 1 : index
+! CHECK: %[[LB:.*]] = arith.constant 50 : index
+! CHECK: %[[UB:.*]] = arith.constant 99 : index
+! CHECK: %[[BOUND:.*]] = acc.bounds lowerbound(%[[LB]] : index) upperbound(%[[UB]] : index) stride(%[[C1]] : index) startIdx(%[[C1]] : index)
+! CHECK: %[[FP_B:.*]] = acc.firstprivate varPtr(%[[B]] : !fir.ref<!fir.array<100xf32>>) bounds(%[[BOUND]]) -> !fir.ref<!fir.array<50xf32>> {name = "b(51:100)"}
+! CHECK: acc.parallel firstprivate(@firstprivatization_ref_50xf32 -> %[[FP_B]] : !fir.ref<!fir.array<50xf32>>)
 
 end program