[flang][openacc] Lower acc declare copyin for module variable

[clementval]

Summary

This patch adds support to lower the copyin clause on OpenACC
declare construct in module declaration.

Depends on D156353

[razvanlupusoru]

Looks great!

flang/lib/Lower/OpenACC.cpp

std::visit(
                 if (!globalOp)
                   llvm::report_fatal_error("could not retrieve global symbol");
                 addDeclareAttr(builder, globalOp.getOperation(), clause);
                 auto crtPos = builder.saveInsertionPoint();
                 modBuilder.setInsertionPointAfter(globalOp);
                 createDeclareGlobalOp<mlir::acc::GlobalConstructorOp, EntryOp,
                                       mlir::acc::DeclareEnterOp, ExitOp>(
                     modBuilder, builder, operandLocation, globalOp, clause);
+                if constexpr (!std::is_same_v<EntryOp, ExitOp>) {
                   createDeclareGlobalOp<mlir::acc::GlobalDestructorOp,
                                         mlir::acc::GetDevicePtrOp,
                                         mlir::acc::DeclareExitOp, ExitOp>(
                       modBuilder, builder, operandLocation, globalOp, clause);
+                }
                 builder.restoreInsertionPoint(crtPos);
               }
             },
             [&](const Fortran::parser::Name &name) {
               TODO(operandLocation, "OpenACC Global Ctor from parser::Name");
             }},
         accObject.u);
   }
if (funcOp) {
         if (const auto *createClause =
                 std::get_if<Fortran::parser::AccClause::Create>(&clause.u)) {
           genGlobalCtorsWithModifier<Fortran::parser::AccClause::Create,
                                      mlir::acc::CreateOp, mlir::acc::DeleteOp>(
               converter, modBuilder, createClause,
               Fortran::parser::AccDataModifier::Modifier::Zero,
               mlir::acc::DataClause::acc_create,
               mlir::acc::DataClause::acc_create_zero);
+        } else if (const auto *copyinClause =
+                       std::get_if<Fortran::parser::AccClause::Copyin>(
+                           &clause.u)) {
+          genGlobalCtorsWithModifier<Fortran::parser::AccClause::Copyin,
+                                     mlir::acc::CopyinOp, mlir::acc::CopyinOp>(
+              converter, modBuilder, copyinClause,
+              Fortran::parser::AccDataModifier::Modifier::ReadOnly,
+              mlir::acc::DataClause::acc_copyin,
+              mlir::acc::DataClause::acc_copyin_readonly);
         } else {
           TODO(clauseLocation, "OpenACC declare clause");
         }
       }
     }
     return;
   }
   llvm_unreachable("unsupported declarative directive");

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

 
 ! CHECK-LABEL: acc.global_dtor @_QMacc_declare_testEdata2_acc_dtor {
 ! CHECK:         %[[GLOBAL_ADDR:.*]] = fir.address_of(@_QMacc_declare_testEdata2) {acc.declare = #acc.declare<dataClause =  acc_create_zero>} : !fir.ref<!fir.array<100000xf32>>
 ! CHECK:         %[[DEVICEPTR:.*]] = acc.getdeviceptr varPtr(%[[GLOBAL_ADDR]] : !fir.ref<!fir.array<100000xf32>>) -> !fir.ref<!fir.array<100000xf32>> {dataClause = #acc<data_clause acc_create_zero>, name = "data2"}
 ! CHECK:         acc.declare_exit dataOperands(%[[DEVICEPTR]] : !fir.ref<!fir.array<100000xf32>>)
 ! CHECK:         acc.delete accPtr(%[[DEVICEPTR]] : !fir.ref<!fir.array<100000xf32>>) {dataClause = #acc<data_clause acc_create_zero>, name = "data2", structured = false}
 ! CHECK:         acc.terminator
 ! CHECK:       }
+
+module acc_declare_copyin_test
+ integer, parameter :: n = 100000
+ real, dimension(n) :: data1
+ !$acc declare copyin(data1)
+end module
+
+
+! CHECK-LABEL: acc.global_ctor @_QMacc_declare_copyin_testEdata1_acc_ctor {
+! CHECK:         %[[GLOBAL_ADDR:.*]] = fir.address_of(@_QMacc_declare_copyin_testEdata1) {acc.declare = #acc.declare<dataClause =  acc_copyin>} : !fir.ref<!fir.array<100000xf32>>
+! CHECK:         %[[COPYIN:.*]] = acc.copyin varPtr(%[[GLOBAL_ADDR]] : !fir.ref<!fir.array<100000xf32>>) -> !fir.ref<!fir.array<100000xf32>> {name = "data1"}
+! CHECK:         acc.declare_enter dataOperands(%[[COPYIN]] : !fir.ref<!fir.array<100000xf32>>)
+! CHECK:         acc.terminator
+! CHECK:       }