[flang][openacc] Add lowering support for deviceptr clause on OpenACC declare

[clementval]

Summary

Lower the deviceptr clause for the OpenACC declare directive.

[razvanlupusoru]

Looks good to me!

flang/lib/Lower/OpenACC.cpp

if (const auto *copyClause =
           std::get<Fortran::parser::AccObjectList>(listWithModifier.t);
       auto crtDataStart = dataClauseOperands.size();
       genDataOperandOperations<mlir::acc::CreateOp>(
           accObjectList, converter, semanticsContext, stmtCtx,
           dataClauseOperands, mlir::acc::DataClause::acc_copyout,
           /*structured=*/true, /*setDeclareAttr=*/true);
       copyoutEntryOperands.append(dataClauseOperands.begin() + crtDataStart,
                                   dataClauseOperands.end());
+    } else if (const auto *devicePtrClause =
+                   std::get_if<Fortran::parser::AccClause::Deviceptr>(
+                       &clause.u)) {
+      genDataOperandOperations<mlir::acc::DevicePtrOp>(
+          devicePtrClause->v, converter, semanticsContext, stmtCtx,
+          dataClauseOperands, mlir::acc::DataClause::acc_deviceptr,
+          /*structured=*/true);
     } else {
       mlir::Location clauseLocation = converter.genLocation(clause.source);
       TODO(clauseLocation, "clause on declare directive");
     }
   }
   builder.create<mlir::acc::DeclareEnterOp>(loc, dataClauseOperands);
 
   if (!createEntryOperands.empty() || !copyEntryOperands.empty() ||

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

 ! CHECK: %[[A:.*]] = fir.alloca !fir.array<100xi32> {acc.declare = #acc.declare<dataClause =  acc_copyout>, bindc_name = "a", uniq_name = "_QMacc_declareFacc_declare_copyoutEa"}
 ! CHECK: %[[CREATE:.*]] = acc.create varPtr(%[[A]] : !fir.ref<!fir.array<100xi32>>) bounds(%{{.*}}) -> !fir.ref<!fir.array<100xi32>> {dataClause = #acc<data_clause acc_copyout>, name = "a"}
 ! CHECK: acc.declare_enter dataOperands(%[[CREATE]] : !fir.ref<!fir.array<100xi32>>)
 ! CHECK: %{{.*}}:2 = fir.do_loop %{{.*}} = %{{.*}} to %{{.*}} step %{{.*}} iter_args(%arg{{.*}} = %{{.*}}) -> (index, i32)
 ! CHECK: acc.declare_exit dataOperands(%[[CREATE]] : !fir.ref<!fir.array<100xi32>>)
 ! CHECK: acc.copyout accPtr(%[[CREATE]] : !fir.ref<!fir.array<100xi32>>) bounds(%{{.*}}) to varPtr(%[[A]] : !fir.ref<!fir.array<100xi32>>) {name = "a"}
 ! CHECK: return
 
+  subroutine acc_declare_deviceptr(a)
+    integer :: a(100), i
+    !$acc declare deviceptr(a)
+
+    do i = 1, 100
+      a(i) = i
+    end do
+  end subroutine
+
+! CHECK-LABEL: func.func @_QMacc_declarePacc_declare_deviceptr(
+! CHECK-SAME: %[[ARG0:.*]]: !fir.ref<!fir.array<100xi32>> {fir.bindc_name = "a"}) {
+! CHECK: %[[DEVICEPTR:.*]] = acc.deviceptr varPtr(%[[ARG0]] : !fir.ref<!fir.array<100xi32>>) bounds(%{{.*}}) -> !fir.ref<!fir.array<100xi32>> {name = "a"}
+! CHECK: acc.declare_enter dataOperands(%[[DEVICEPTR]] : !fir.ref<!fir.array<100xi32>>)
+! CHECK: %{{.*}}:2 = fir.do_loop %{{.*}} = %{{.*}} to %{{.*}} step %{{.*}} iter_args(%arg{{.*}} = %{{.*}}) -> (index, i32)
+! CHECK-NOT: acc.declare_exit
+
 end module