openmp-utils.h

//===-- flang/Parser/openmp-utils.h ---------------------------------------===//
//
// 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
//
//===----------------------------------------------------------------------===//
//
// Common OpenMP utilities.
//
//===----------------------------------------------------------------------===//
 
#ifndef FORTRAN_PARSER_OPENMP_UTILS_H
#define FORTRAN_PARSER_OPENMP_UTILS_H
 
#include "flang/Common/indirection.h"
#include "flang/Parser/parse-tree.h"
#include "llvm/Frontend/OpenMP/OMP.h"
 
#include <cassert>
#include <tuple>
#include <type_traits>
#include <utility>
#include <variant>
#include <vector>
 
namespace Fortran::parser::omp {
 
template <typename T> constexpr auto addr_if(std::optional<T> &x) {
  return x ? &*x : nullptr;
}
template <typename T> constexpr auto addr_if(const std::optional<T> &x) {
  return x ? &*x : nullptr;
}
 
namespace detail {
struct DirectiveNameScope {
  static OmpDirectiveName MakeName(CharBlock source = {},
      llvm::omp::Directive id = llvm::omp::Directive::OMPD_unknown) {
    OmpDirectiveName name;
    name.source = source;
    name.v = id;
    return name;
  }
 
  static OmpDirectiveName GetOmpDirectiveName(const OmpDirectiveName &x) {
    return x;
  }
 
  static OmpDirectiveName GetOmpDirectiveName(const OmpBeginLoopDirective &x) {
    return x.DirName();
  }
 
  static OmpDirectiveName GetOmpDirectiveName(const OpenMPSectionConstruct &x) {
    if (auto &spec{std::get<std::optional<OmpDirectiveSpecification>>(x.t)}) {
      return spec->DirName();
    } else {
      return MakeName({}, llvm::omp::Directive::OMPD_section);
    }
  }
 
  static OmpDirectiveName GetOmpDirectiveName(
      const OmpBeginSectionsDirective &x) {
    return x.DirName();
  }
 
  template <typename T>
  static OmpDirectiveName GetOmpDirectiveName(const T &x) {
    if constexpr (WrapperTrait<T>) {
      if constexpr (std::is_same_v<T, OpenMPCancelConstruct> ||
          std::is_same_v<T, OpenMPCancellationPointConstruct> ||
          std::is_same_v<T, OpenMPDepobjConstruct> ||
          std::is_same_v<T, OpenMPFlushConstruct> ||
          std::is_same_v<T, OpenMPInteropConstruct> ||
          std::is_same_v<T, OpenMPSimpleStandaloneConstruct> ||
          std::is_same_v<T, OpenMPGroupprivate>) {
        return x.v.DirName();
      } else {
        return GetOmpDirectiveName(x.v);
      }
    } else if constexpr (TupleTrait<T>) {
      if constexpr (std::is_base_of_v<OmpBlockConstruct, T>) {
        return std::get<OmpBeginDirective>(x.t).DirName();
      } else {
        return GetFromTuple(
            x.t, std::make_index_sequence<std::tuple_size_v<decltype(x.t)>>{});
      }
    } else if constexpr (UnionTrait<T>) {
      return common::visit(
          [](auto &&s) { return GetOmpDirectiveName(s); }, x.u);
    } else {
      return MakeName();
    }
  }
 
  template <typename... Ts, size_t... Is>
  static OmpDirectiveName GetFromTuple(
      const std::tuple<Ts...> &t, std::index_sequence<Is...>) {
    OmpDirectiveName name = MakeName();
    auto accumulate = [&](const OmpDirectiveName &n) {
      if (name.v == llvm::omp::Directive::OMPD_unknown) {
        name = n;
      } else {
        assert(
            n.v == llvm::omp::Directive::OMPD_unknown && "Conflicting names");
      }
    };
    (accumulate(GetOmpDirectiveName(std::get<Is>(t))), ...);
    return name;
  }
 
  template <typename T>
  static OmpDirectiveName GetOmpDirectiveName(const common::Indirection<T> &x) {
    return GetOmpDirectiveName(x.value());
  }
};
} // namespace detail
 
template <typename T> OmpDirectiveName GetOmpDirectiveName(const T &x) {
  return detail::DirectiveNameScope::GetOmpDirectiveName(x);
}
 
const OpenMPDeclarativeConstruct *GetOmp(const DeclarationConstruct &x);
const OpenMPConstruct *GetOmp(const ExecutionPartConstruct &x);
 
const OpenMPLoopConstruct *GetOmpLoop(const ExecutionPartConstruct &x);
const DoConstruct *GetDoConstruct(const ExecutionPartConstruct &x);
 
// Is the template argument "Statement<T>" for some T?
template <typename T> struct IsStatement {
  static constexpr bool value{false};
};
template <typename T> struct IsStatement<Statement<T>> {
  static constexpr bool value{true};
};
 
std::optional<Label> GetStatementLabel(const ExecutionPartConstruct &x);
std::optional<Label> GetFinalLabel(const OpenMPConstruct &x);
 
const OmpObjectList *GetOmpObjectList(const OmpClause &clause);
 
template <typename T>
const T *GetFirstArgument(const OmpDirectiveSpecification &spec) {
  for (const OmpArgument &arg : spec.Arguments().v) {
    if (auto *t{std::get_if<T>(&arg.u)}) {
      return t;
    }
  }
  return nullptr;
}
 
const BlockConstruct *GetFortranBlockConstruct(
    const ExecutionPartConstruct &epc);
const Block &GetInnermostExecPart(const Block &block);
bool IsStrictlyStructuredBlock(const Block &block);
 
const OmpCombinerExpression *GetCombinerExpr(
    const OmpReductionSpecifier &rspec);
const OmpInitializerExpression *GetInitializerExpr(const OmpClause &init);
 
struct OmpAllocateInfo {
  std::vector<const OmpAllocateDirective *> dirs;
  const ExecutionPartConstruct *body{nullptr};
};
 
OmpAllocateInfo SplitOmpAllocate(const OmpAllocateDirective &x);
 
} // namespace Fortran::parser::omp
 
#endif // FORTRAN_PARSER_OPENMP_UTILS_H