ReductionProcessor.h

//===-- Lower/OpenMP/ReductionProcessor.h -----------------------*- C++ -*-===//
//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See https://llvm.org/LICENSE.txt for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
//
//===----------------------------------------------------------------------===//
//
// Coding style: https://mlir.llvm.org/getting_started/DeveloperGuide/
//
//===----------------------------------------------------------------------===//
 
#ifndef FORTRAN_LOWER_REDUCTIONPROCESSOR_H
#define FORTRAN_LOWER_REDUCTIONPROCESSOR_H
 
#include "flang/Lower/AbstractConverter.h"
#include "flang/Lower/OpenMP/Clauses.h"
#include "flang/Optimizer/Builder/FIRBuilder.h"
#include "flang/Optimizer/Dialect/FIRType.h"
#include "flang/Parser/parse-tree.h"
#include "flang/Semantics/symbol.h"
#include "flang/Semantics/type.h"
#include "mlir/IR/Location.h"
#include "mlir/IR/Types.h"
#include "llvm/ADT/ArrayRef.h"
 
namespace mlir {
namespace omp {
class DeclareReductionOp;
} // namespace omp
} // namespace mlir
 
namespace Fortran {
namespace lower {
class AbstractConverter;
} // namespace lower
namespace semantics {
class SemanticsContext;
} // namespace semantics
} // namespace Fortran
 
namespace Fortran {
namespace lower {
namespace omp {
 
class ReductionProcessor {
public:
  // ompOrig: mold/original variable
  // ompPriv: private allocation (may be null for by-value reductions)
  using GenInitValueCBTy = std::function<mlir::Value(
      fir::FirOpBuilder &builder, mlir::Location loc, mlir::Type type,
      mlir::Value ompOrig, mlir::Value ompPriv)>;
  using GenCombinerCBTy = std::function<void(
      fir::FirOpBuilder &builder, mlir::Location loc, mlir::Type type,
      mlir::Value op1, mlir::Value op2, bool isByRef)>;
 
  // TODO: Move this enumeration to the OpenMP dialect
  enum ReductionIdentifier {
    ID,
    USER_DEF_OP,
    ADD,
    SUBTRACT,
    MULTIPLY,
    AND,
    OR,
    EQV,
    NEQV,
    MAX,
    MIN,
    IAND,
    IOR,
    IEOR
  };
 
  static bool doReductionByRef(mlir::Type reductionType);
  static bool doReductionByRef(mlir::Value reductionVar);
 
  static ReductionIdentifier
  getReductionType(const omp::clause::ProcedureDesignator &pd);
 
  static ReductionIdentifier
  getReductionType(omp::clause::DefinedOperator::IntrinsicOperator intrinsicOp);

  static parser::DefinedOperator::IntrinsicOperator
  toParserIntrinsicOperator(omp::clause::DefinedOperator::IntrinsicOperator op);
 
  static ReductionIdentifier
  getReductionType(const fir::ReduceOperationEnum &pd);
 
  static bool
  supportedIntrinsicProcReduction(const omp::clause::ProcedureDesignator &pd);
 
  static const semantics::SourceName
  getRealName(const semantics::Symbol *symbol);
 
  static const semantics::SourceName
  getRealName(const omp::clause::ProcedureDesignator &pd);
 
  static std::string getReductionName(llvm::StringRef name,
                                      const fir::KindMapping &kindMap,
                                      mlir::Type ty, bool isByRef);
 
  static std::string getReductionName(ReductionIdentifier redId,
                                      const fir::KindMapping &kindMap,
                                      mlir::Type ty, bool isByRef);

  static std::string
  getScopedUserReductionName(AbstractConverter &converter,
                             const semantics::Symbol &reductionSymbol,
                             mlir::Type reductionType, bool isByRef);

  static int getOperationIdentity(ReductionIdentifier redId,
                                  mlir::Location loc);
 
  static mlir::Value getReductionInitValue(mlir::Location loc, mlir::Type type,
                                           ReductionIdentifier redId,
                                           fir::FirOpBuilder &builder);
 
  template <typename FloatOp, typename IntegerOp>
  static mlir::Value getReductionOperation(fir::FirOpBuilder &builder,
                                           mlir::Type type, mlir::Location loc,
                                           mlir::Value op1, mlir::Value op2);
  template <typename FloatOp, typename IntegerOp, typename ComplexOp>
  static mlir::Value getReductionOperation(fir::FirOpBuilder &builder,
                                           mlir::Type type, mlir::Location loc,
                                           mlir::Value op1, mlir::Value op2);
 
  static mlir::Value createScalarCombiner(fir::FirOpBuilder &builder,
                                          mlir::Location loc,
                                          ReductionIdentifier redId,
                                          mlir::Type type, mlir::Value op1,
                                          mlir::Value op2);
  template <typename DeclareRedType>
  static DeclareRedType createDeclareReductionHelper(
      AbstractConverter &converter, llvm::StringRef reductionOpName,
      mlir::Type type, mlir::Location loc, bool isByRef,
      GenCombinerCBTy genCombinerCB, GenInitValueCBTy genInitValueCB,
      const semantics::Symbol *sym = nullptr);

  template <typename OpType>
  static OpType createDeclareReduction(AbstractConverter &builder,
                                       llvm::StringRef reductionOpName,
                                       const ReductionIdentifier redId,
                                       mlir::Type type, mlir::Location loc,
                                       bool isByRef);

  template <typename OpType, typename RedOperatorListTy>
  static bool processReductionArguments(
      mlir::Location currentLocation, lower::AbstractConverter &converter,
      const RedOperatorListTy &redOperatorList,
      llvm::SmallVectorImpl<mlir::Value> &reductionVars,
      llvm::SmallVectorImpl<bool> &reduceVarByRef,
      llvm::SmallVectorImpl<mlir::Attribute> &reductionDeclSymbols,
      const llvm::SmallVectorImpl<const semantics::Symbol *> &reductionSymbols,
      llvm::ArrayRef<Object> reductionObjects, lower::SymMap &symMap,
      semantics::SemanticsContext *semaCtx = nullptr,
      llvm::DenseMap<const semantics::Symbol *, mlir::Value>
          *reductionVarCache = nullptr);

  // TODO support more types of objects
  // to avoid Reduction clauses being represented in FIR as full arrays.
  static bool isExpressionLoweredAsReductionObject(const Object *object);
};
 
template <typename FloatOp, typename IntegerOp>
mlir::Value
ReductionProcessor::getReductionOperation(fir::FirOpBuilder &builder,
                                          mlir::Type type, mlir::Location loc,
                                          mlir::Value op1, mlir::Value op2) {
  type = fir::unwrapRefType(type);
  assert(type.isIntOrIndexOrFloat() &&
         "only integer, float and complex types are currently supported");
  if (type.isIntOrIndex())
    return IntegerOp::create(builder, loc, op1, op2);
  return FloatOp::create(builder, loc, op1, op2);
}
 
template <typename FloatOp, typename IntegerOp, typename ComplexOp>
mlir::Value
ReductionProcessor::getReductionOperation(fir::FirOpBuilder &builder,
                                          mlir::Type type, mlir::Location loc,
                                          mlir::Value op1, mlir::Value op2) {
  assert((type.isIntOrIndexOrFloat() || fir::isa_complex(type)) &&
         "only integer, float and complex types are currently supported");
  if (type.isIntOrIndex())
    return IntegerOp::create(builder, loc, op1, op2);
  if (fir::isa_real(type))
    return FloatOp::create(builder, loc, op1, op2);
  return ComplexOp::create(builder, loc, op1, op2);
}
 
} // namespace omp
} // namespace lower
} // namespace Fortran
 
#endif // FORTRAN_LOWER_REDUCTIONPROCESSOR_H