[MLIR][OpenMP] Add Lowering support for OpenMP Declare Mapper directive

This patch adds HLFIR/FIR lowering support for OpenMP Declare Mapper directive.

Author: TIFitis

flang/lib/Lower/OpenMP/OpenMP.cpp

@@ -40,6 +40,7 @@
 #include "mlir/Transforms/RegionUtils.h"
 #include "llvm/ADT/STLExtras.h"
 #include "llvm/Frontend/OpenMP/OMPConstants.h"
+#include <string>
 
 using namespace Fortran::lower::omp;
 using namespace Fortran::common::openmp;
@@ -3119,7 +3120,39 @@ static void
 genOMP(lower::AbstractConverter &converter, lower::SymMap &symTable,
        semantics::SemanticsContext &semaCtx, lower::pft::Evaluation &eval,
        const parser::OpenMPDeclareMapperConstruct &declareMapperConstruct) {
-  TODO(converter.getCurrentLocation(), "OpenMPDeclareMapperConstruct");
+  fir::FirOpBuilder &firOpBuilder = converter.getFirOpBuilder();
+  lower::StatementContext stmtCtx;
+  const auto &spec =
+      std::get<parser::OmpDeclareMapperSpecifier>(declareMapperConstruct.t);
+  const auto &mapperName{std::get<std::optional<parser::Name>>(spec.t)};
+  const auto &varType{std::get<parser::TypeSpec>(spec.t)};
+  const auto &varName{std::get<parser::Name>(spec.t)};
+  std::stringstream mapperNameStr;
+  if (mapperName.has_value()) {
+    mapperNameStr << mapperName->ToString();
+  } else {
+    mapperNameStr << "default_"
+                  << varType.declTypeSpec->derivedTypeSpec().name().ToString();
+  }
+
+  mlir::OpBuilder::InsertPoint insPt = firOpBuilder.saveInsertionPoint();
+  firOpBuilder.setInsertionPointToStart(converter.getModuleOp().getBody());
+  auto mlirType = converter.genType(varType.declTypeSpec->derivedTypeSpec());
+  auto varVal = firOpBuilder.createTemporaryAlloc(
+      converter.getCurrentLocation(), mlirType, varName.ToString());
+  symTable.addSymbol(*varName.symbol, varVal);
+
+  mlir::omp::DeclareMapperOperands clauseOps;
+  const auto *clauseList{
+      parser::Unwrap<parser::OmpClauseList>(declareMapperConstruct.t)};
+  List<Clause> clauses = makeClauses(*clauseList, semaCtx);
+  ClauseProcessor cp(converter, semaCtx, clauses);
+  cp.processMap(converter.getCurrentLocation(), stmtCtx, clauseOps);
+  auto declMapperOp = firOpBuilder.create<mlir::omp::DeclareMapperOp>(
+      converter.getCurrentLocation(), mapperNameStr.str(), varVal, mlirType,
+      clauseOps.mapVars);
+  converter.getMLIRSymbolTable()->insert(declMapperOp.getOperation());
+  firOpBuilder.restoreInsertionPoint(insPt);
 }
 
 static void

flang/lib/Optimizer/OpenMP/MapInfoFinalization.cpp

@@ -464,7 +464,8 @@ class MapInfoFinalizationPass
     for (auto *user : mapOp->getUsers()) {
       if (llvm::isa<mlir::omp::TargetOp, mlir::omp::TargetDataOp,
                     mlir::omp::TargetUpdateOp, mlir::omp::TargetExitDataOp,
-                    mlir::omp::TargetEnterDataOp>(user))
+                    mlir::omp::TargetEnterDataOp, mlir::omp::DeclareMapperOp>(
+              user))
         return user;
 
       if (auto mapUser = llvm::dyn_cast<mlir::omp::MapInfoOp>(user))

flang/test/Lower/OpenMP/Todo/omp-declare-mapper.f90

@@ -10,7 +10,7 @@ subroutine declare_mapper_1
  type my_type
    integer              :: num_vals
    integer, allocatable :: values(:)
- end type 
+ end type
 
  type my_type2
    type (my_type)        :: my_type_var
@@ -21,7 +21,7 @@ subroutine declare_mapper_1
   type (my_type2)        :: t
   real                   :: x, y(nvals)
   !$omp declare mapper (my_type :: var) map (var, var%values (1:var%num_vals))
-!CHECK: not yet implemented: OpenMPDeclareMapperConstruct
+!CHECK: not yet implemented: lowering symbol to HLFIR
 end subroutine declare_mapper_1
 
 
@@ -31,7 +31,7 @@ subroutine declare_mapper_2
  type my_type
    integer              :: num_vals
    integer, allocatable :: values(:)
- end type 
+ end type
 
  type my_type2
    type (my_type)        :: my_type_var
@@ -43,5 +43,5 @@ subroutine declare_mapper_2
   real                   :: x, y(nvals)
   !$omp declare mapper (my_mapper : my_type2 :: v) map (v%arr, x, y(:)) &
   !$omp&                map (alloc : v%temp)
-!CHECK: not yet implemented: OpenMPDeclareMapperConstruct
+!CHECK: not yet implemented: lowering symbol to HLFIR
 end subroutine declare_mapper_2

flang/test/Lower/OpenMP/declare-mapper.f90

@@ -0,0 +1,31 @@
+! This test checks lowering of OpenMP declare mapper Directive.
+
+! RUN: split-file %s %t
+! RUN: %flang_fc1 -emit-hlfir -fopenmp -fopenmp-version=50 %t/declare-mapper-1.f90 -o - | FileCheck %t/declare-mapper-1.f90
+! RUN  %flang_fc1 -emit-hlfir -fopenmp -fopenmp-version=50 %t/declare-mapper-2.f90 -o - | FileCheck %t/declare-mapper-2.f90
+
+!--- declare-mapper-1.f90
+subroutine mapper
+   implicit none
+   type my_type
+      integer, pointer :: my_buffer
+      integer :: my_buffer_size
+   end type
+   !CHECK: %[[MY_VAR:.*]] = fir.alloca ![[VAR_TYPE:.*]] {bindc_name = "my_var"}
+   !CHECK: %[[MAP_INFO:.*]] = omp.map.info var_ptr(%[[MY_VAR]] : !fir.ref<![[VAR_TYPE]]>, ![[VAR_TYPE]]) map_clauses(tofrom) capture(ByRef) -> !fir.ref<![[VAR_TYPE]]> {name = "my_var"}
+   !CHECK: omp.declare_mapper @my_mapper : %[[MY_VAR]] : !fir.ref<![[VAR_TYPE]]> : ![[VAR_TYPE]] map_entries(%[[MAP_INFO]] : !fir.ref<![[VAR_TYPE]]>)
+   !$omp DECLARE MAPPER(my_mapper : my_type :: my_var) map(tofrom : my_var)
+end subroutine
+
+!--- declare-mapper-2.f90
+subroutine mapper_default
+   implicit none
+   type my_type
+      integer, pointer :: my_buffer
+      integer :: my_buffer_size
+   end type
+   !CHECK: %[[MY_VAR:.*]] = fir.alloca ![[VAR_TYPE:.*]] {bindc_name = "my_var"}
+   !CHECK: %[[MAP_INFO:.*]] = omp.map.info var_ptr(%[[MY_VAR]] : !fir.ref<![[VAR_TYPE]]>, ![[VAR_TYPE]]) map_clauses(tofrom) capture(ByRef) -> !fir.ref<![[VAR_TYPE]]> {name = "my_var"}
+   !CHECK: omp.declare_mapper @default_my_type : %[[MY_VAR]] : !fir.ref<![[VAR_TYPE]]> : ![[VAR_TYPE]] map_entries(%[[MAP_INFO]] : !fir.ref<![[VAR_TYPE]]>)
+   !$omp DECLARE MAPPER(my_type :: my_var) map(tofrom : my_var)
+end subroutine