[flang][openacc] Lower host_data construct

[clementval]

Summary

Lower host_data construct to the acc.host_data operation.

Depends on D150289

[clementval]

Rebase

[jeanPerier]

LGTM

[razvanlupusoru]

LGTM

flang/lib/Lower/OpenACC.cpp

genDataExitOperations<mlir::acc::AttachOp, mlir::acc::DetachOp>(
       builder, attachEntryOperands, /*structured=*/true, /*implicit=*/false);
   genDataExitOperations<mlir::acc::CreateOp, mlir::acc::DeleteOp>(
       builder, createEntryOperands, /*structured=*/true, /*implicit=*/false);
 
   builder.restoreInsertionPoint(insPt);
 }
 
 static void
+genACCHostDataOp(Fortran::lower::AbstractConverter &converter,
+                 mlir::Location currentLocation,
+                 Fortran::semantics::SemanticsContext &semanticsContext,
+                 Fortran::lower::StatementContext &stmtCtx,
+                 const Fortran::parser::AccClauseList &accClauseList) {
+  mlir::Value ifCond;
+  llvm::SmallVector<mlir::Value> dataOperands;
+  bool addIfPresentAttr = false;
+
+  fir::FirOpBuilder &builder = converter.getFirOpBuilder();
+
+  for (const Fortran::parser::AccClause &clause : accClauseList.v) {
+    mlir::Location clauseLocation = converter.genLocation(clause.source);
+    if (const auto *ifClause =
+            std::get_if<Fortran::parser::AccClause::If>(&clause.u)) {
+      genIfClause(converter, clauseLocation, ifClause, ifCond, stmtCtx);
+    } else if (const auto *useDevice =
+                   std::get_if<Fortran::parser::AccClause::UseDevice>(
+                       &clause.u)) {
+      genDataOperandOperations<mlir::acc::UseDeviceOp>(
+          useDevice->v, converter, semanticsContext, stmtCtx, dataOperands,
+          mlir::acc::DataClause::acc_use_device,
+          /*structured=*/true);
+    } else if (std::get_if<Fortran::parser::AccClause::IfPresent>(&clause.u)) {
+      addIfPresentAttr = true;
+    }
+  }
+
+  if (ifCond) {
+    if (auto cst =
+            mlir::dyn_cast<mlir::arith::ConstantOp>(ifCond.getDefiningOp()))
+      if (auto boolAttr = cst.getValue().dyn_cast<mlir::BoolAttr>()) {
+        if (boolAttr.getValue()) {
+          // get rid of the if condition if it is always true.
+          ifCond = mlir::Value();
+        } else {
+          // Do not generate the acc.host_data op if the if condition is always
+          // false.
+          return;
+        }
+      }
+  }
+
+  // Prepare the operand segment size attribute and the operands value range.
+  llvm::SmallVector<mlir::Value> operands;
+  llvm::SmallVector<int32_t> operandSegments;
+  addOperand(operands, operandSegments, ifCond);
+  addOperands(operands, operandSegments, dataOperands);
+
+  auto hostDataOp =
+      createRegionOp<mlir::acc::HostDataOp, mlir::acc::TerminatorOp>(
+          builder, currentLocation, operands, operandSegments);
+
+  if (addIfPresentAttr)
+    hostDataOp.setIfPresentAttr(builder.getUnitAttr());
+}
+
+static void
 genACC(Fortran::lower::AbstractConverter &converter,
        Fortran::semantics::SemanticsContext &semanticsContext,
        Fortran::lower::pft::Evaluation &eval,
        const Fortran::parser::OpenACCBlockConstruct &blockConstruct) {
   const auto &beginBlockDirective =
       std::get<Fortran::parser::AccBeginBlockDirective>(blockConstruct.t);
   const auto &blockDirective =
       std::get<Fortran::parser::AccBlockDirective>(beginBlockDirective.t);
genACCDataOp(converter, currentLocation, semanticsContext, stmtCtx,
                  accClauseList);
   } else if (blockDirective.v == llvm::acc::ACCD_serial) {
     createComputeOp<mlir::acc::SerialOp>(
         converter, currentLocation, semanticsContext, stmtCtx, accClauseList);
   } else if (blockDirective.v == llvm::acc::ACCD_kernels) {
     createComputeOp<mlir::acc::KernelsOp>(
         converter, currentLocation, semanticsContext, stmtCtx, accClauseList);
   } else if (blockDirective.v == llvm::acc::ACCD_host_data) {
-    TODO(currentLocation, "host_data construct lowering");
+    genACCHostDataOp(converter, currentLocation, semanticsContext, stmtCtx,
+                     accClauseList);
   }
 }
 
 static void
 genACC(Fortran::lower::AbstractConverter &converter,
        Fortran::semantics::SemanticsContext &semanticsContext,
        Fortran::lower::pft::Evaluation &eval,
        const Fortran::parser::OpenACCCombinedConstruct &combinedConstruct) {

flang/test/Lower/OpenACC/acc-host-data.f90

+! This test checks lowering of OpenACC host_data directive.
+
+! RUN: bbc -fopenacc -emit-fir %s -o - | FileCheck %s
+
+subroutine acc_host_data()
+  real, dimension(10) :: a
+  logical :: ifCondition = .TRUE.
+
+! CHECK: %[[A:.*]] = fir.alloca !fir.array<10xf32> {bindc_name = "a", uniq_name = "_QFacc_host_dataEa"}
+! CHECK: %[[IFCOND:.*]] = fir.address_of(@_QFacc_host_dataEifcondition) : !fir.ref<!fir.logical<4>>
+
+  !$acc host_data use_device(a)
+  !$acc end host_data
+
+! CHECK: %[[BOUND:.*]] = acc.bounds lowerbound(%{{.*}} : index) upperbound(%{{.*}} : index) stride(%{{.*}} : index) startIdx(%{{.*}} : index)
+! CHECK: %[[DA:.*]] = acc.use_device varPtr(%[[A]] : !fir.ref<!fir.array<10xf32>>) bounds(%[[BOUND]]) -> !fir.ref<!fir.array<10xf32>> {name = "a"}
+! CHECK: acc.host_data dataOperands(%[[DA]] : !fir.ref<!fir.array<10xf32>>)
+
+  !$acc host_data use_device(a) if_present
+  !$acc end host_data
+
+! CHECK: %[[BOUND:.*]] = acc.bounds lowerbound(%{{.*}} : index) upperbound(%{{.*}} : index) stride(%{{.*}} : index) startIdx(%{{.*}} : index)
+! CHECK: %[[DA:.*]] = acc.use_device varPtr(%[[A]] : !fir.ref<!fir.array<10xf32>>) bounds(%[[BOUND]]) -> !fir.ref<!fir.array<10xf32>> {name = "a"}
+! CHECK: acc.host_data dataOperands(%[[DA]] : !fir.ref<!fir.array<10xf32>>) {
+! CHECK: } attributes {ifPresent}
+
+  !$acc host_data use_device(a) if(ifCondition)
+  !$acc end host_data
+
+! CHECK: %[[BOUND:.*]] = acc.bounds lowerbound(%{{.*}} : index) upperbound(%{{.*}} : index) stride(%{{.*}} : index) startIdx(%{{.*}} : index)
+! CHECK: %[[DA:.*]] = acc.use_device varPtr(%[[A]] : !fir.ref<!fir.array<10xf32>>) bounds(%[[BOUND]]) -> !fir.ref<!fir.array<10xf32>> {name = "a"}
+! CHECK: %[[LOAD_IFCOND:.*]] = fir.load %[[IFCOND]] : !fir.ref<!fir.logical<4>>
+! CHECK: %[[IFCOND_I1:.*]] = fir.convert %[[LOAD_IFCOND]] : (!fir.logical<4>) -> i1
+! CHECK: acc.host_data if(%[[IFCOND_I1]]) dataOperands(%[[DA]] : !fir.ref<!fir.array<10xf32>>)
+
+  !$acc host_data use_device(a) if(.true.)
+  !$acc end host_data
+
+! CHECK: %[[BOUND:.*]] = acc.bounds lowerbound(%{{.*}} : index) upperbound(%{{.*}} : index) stride(%{{.*}} : index) startIdx(%{{.*}} : index)
+! CHECK: %[[DA:.*]] = acc.use_device varPtr(%[[A]] : !fir.ref<!fir.array<10xf32>>) bounds(%[[BOUND]]) -> !fir.ref<!fir.array<10xf32>> {name = "a"}
+! CHECK: acc.host_data dataOperands(%[[DA]] : !fir.ref<!fir.array<10xf32>>)
+
+  !$acc host_data use_device(a) if(.false.)
+    a = 1.0
+  !$acc end host_data
+
+! CHECK-NOT: acc.host_data
+! CHECK: fir.do_loop
+
+end subroutine