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

[clementval]

Summary

Depends on D156828

[razvanlupusoru]

I think this operation needs an acc.declare_exit + acc.delete. The device_resident variable needs removed from device memory on exit from its implicit data region.

[clementval]

In D156829#4555617, @razvanlupusoru wrote:

I think this operation needs an acc.declare_exit + acc.delete. The device_resident variable needs removed from device memory on exit from its implicit data region.

Makes sense! I'll update the patch

[clementval]

Add exit operation

[clementval]

Rebase

[razvanlupusoru]

Looks good to me!

flang/lib/Lower/OpenACC.cpp

 
 static void
 genDeclareInFunction(Fortran::lower::AbstractConverter &converter,
                      Fortran::semantics::SemanticsContext &semanticsContext,
                      Fortran::lower::StatementContext &fctCtx,
                      mlir::Location loc,
                      const Fortran::parser::AccClauseList &accClauseList) {
   llvm::SmallVector<mlir::Value> dataClauseOperands, copyEntryOperands,
-      createEntryOperands, copyoutEntryOperands;
+      createEntryOperands, copyoutEntryOperands, deviceResidentEntryOperands;
   Fortran::lower::StatementContext stmtCtx;
   fir::FirOpBuilder &builder = converter.getFirOpBuilder();
   for (const Fortran::parser::AccClause &clause : accClauseList.v) {
     if (const auto *copyClause =
             std::get_if<Fortran::parser::AccClause::Copy>(&clause.u)) {
       auto crtDataStart = dataClauseOperands.size();
       genDataOperandOperations<mlir::acc::CopyinOp>(
           copyClause->v, converter, semanticsContext, stmtCtx,
if (const auto *copyClause =
           dataClauseOperands, mlir::acc::DataClause::acc_deviceptr,
           /*structured=*/true);
     } else if (const auto *linkClause =
                    std::get_if<Fortran::parser::AccClause::Link>(&clause.u)) {
       genDataOperandOperations<mlir::acc::DeclareLinkOp>(
           linkClause->v, converter, semanticsContext, stmtCtx,
           dataClauseOperands, mlir::acc::DataClause::acc_declare_link,
           /*structured=*/true);
+    } else if (const auto *deviceResidentClause =
+                   std::get_if<Fortran::parser::AccClause::DeviceResident>(
+                       &clause.u)) {
+      auto crtDataStart = dataClauseOperands.size();
+      genDataOperandOperations<mlir::acc::DeclareDeviceResidentOp>(
+          deviceResidentClause->v, converter, semanticsContext, stmtCtx,
+          dataClauseOperands,
+          mlir::acc::DataClause::acc_declare_device_resident,
+          /*structured=*/true);
+      deviceResidentEntryOperands.append(
+          dataClauseOperands.begin() + crtDataStart, dataClauseOperands.end());
     } 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() ||
-      !copyoutEntryOperands.empty()) {
+      !copyoutEntryOperands.empty() || !deviceResidentEntryOperands.empty()) {
     // Attach declare exit operation generation to function context.
     fctCtx.attachCleanup([&builder, loc, dataClauseOperands,
                           createEntryOperands, copyEntryOperands,
-                          copyoutEntryOperands]() {
+                          copyoutEntryOperands, deviceResidentEntryOperands]() {
       builder.create<mlir::acc::DeclareExitOp>(loc, dataClauseOperands);
       genDataExitOperations<mlir::acc::CreateOp, mlir::acc::DeleteOp>(
           builder, createEntryOperands, /*structured=*/true,
           /*implicit=*/false);
+      genDataExitOperations<mlir::acc::DeclareDeviceResidentOp,
+                            mlir::acc::DeleteOp>(
+          builder, deviceResidentEntryOperands, /*structured=*/true,
+          /*implicit=*/false);
       genDataExitOperations<mlir::acc::CopyinOp, mlir::acc::CopyoutOp>(
           builder, copyEntryOperands, /*structured=*/true, /*implicit=*/false);
       genDataExitOperations<mlir::acc::CreateOp, mlir::acc::CopyoutOp>(
           builder, copyoutEntryOperands, /*structured=*/true,
           /*implicit=*/false);
     });
   }
 }

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

 
 ! CHECK-LABEL: func.func @_QMacc_declarePacc_declare_link(
 ! CHECK-SAME: %[[ARG0:.*]]: !fir.ref<!fir.array<100xi32>> {fir.bindc_name = "a"})
 ! CHECK: %[[LINK:.*]] = acc.declare_link varPtr(%[[ARG0]] : !fir.ref<!fir.array<100xi32>>) bounds(%{{.*}}) -> !fir.ref<!fir.array<100xi32>> {name = "a"}
 ! CHECK: acc.declare_enter dataOperands(%[[LINK]] : !fir.ref<!fir.array<100xi32>>)
 ! CHECK: %{{.*}}:2 = fir.do_loop %{{.*}} = %{{.*}} to %{{.*}} step %{{.*}} iter_args(%arg{{.*}} = %{{.*}}) -> (index, i32)
 ! CHECK-NOT: acc.declare_exit
 
+  subroutine acc_declare_device_resident(a)
+    integer :: a(100), i
+    !$acc declare device_resident(a)
+
+    do i = 1, 100
+      a(i) = i
+    end do
+  end subroutine
+
+! CHECK-LABEL: func.func @_QMacc_declarePacc_declare_device_resident(
+! CHECK-SAME: %[[ARG0:.*]]: !fir.ref<!fir.array<100xi32>> {fir.bindc_name = "a"})
+! CHECK: %[[DEVICERES:.*]] = acc.declare_device_resident varPtr(%[[ARG0]] : !fir.ref<!fir.array<100xi32>>) bounds(%{{.*}}) -> !fir.ref<!fir.array<100xi32>> {name = "a"}
+! CHECK: acc.declare_enter dataOperands(%[[DEVICERES]] : !fir.ref<!fir.array<100xi32>>)
+! CHECK: %{{.*}}:2 = fir.do_loop %{{.*}} = %{{.*}} to %{{.*}} step %{{.*}} iter_args(%arg{{.*}} = %{{.*}}) -> (index, i32)
+! CHECK: acc.declare_exit dataOperands(%[[DEVICERES]] : !fir.ref<!fir.array<100xi32>>) 
+! CHECK: acc.delete accPtr(%[[DEVICERES]] : !fir.ref<!fir.array<100xi32>>) bounds(%{{.*}}) {dataClause = #acc<data_clause acc_declare_device_resident>, name = "a"} 
+
 end module