1//===-- Decomposer.cpp -- Compound directive decomposition ----------------===//
2//
3// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4// See https://llvm.org/LICENSE.txt for license information.
5// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6//
7//===----------------------------------------------------------------------===//
8//
9// Coding style: https://mlir.llvm.org/getting_started/DeveloperGuide/
10//
11//===----------------------------------------------------------------------===//
12
13#include "Decomposer.h"
14
15#include "Clauses.h"
16#include "Utils.h"
17#include "flang/Lower/PFTBuilder.h"
18#include "flang/Semantics/semantics.h"
19#include "flang/Tools/CrossToolHelpers.h"
20#include "mlir/IR/BuiltinOps.h"
21#include "llvm/ADT/ArrayRef.h"
22#include "llvm/ADT/STLExtras.h"
23#include "llvm/ADT/SmallVector.h"
24#include "llvm/Frontend/OpenMP/ClauseT.h"
25#include "llvm/Frontend/OpenMP/ConstructDecompositionT.h"
26#include "llvm/Frontend/OpenMP/OMP.h"
27#include "llvm/Support/raw_ostream.h"
28
29#include <optional>
30#include <utility>
31#include <variant>
32
33using namespace Fortran;
34
35namespace {
36using namespace Fortran::lower::omp;
37
38struct ConstructDecomposition {
39 ConstructDecomposition(mlir::ModuleOp modOp,
40 semantics::SemanticsContext &semaCtx,
41 lower::pft::Evaluation &ev,
42 llvm::omp::Directive compound,
43 const List<Clause> &clauses)
44 : semaCtx(semaCtx), mod(modOp), eval(ev) {
45 tomp::ConstructDecompositionT decompose(getOpenMPVersionAttribute(modOp),
46 *this, compound,
47 llvm::ArrayRef(clauses));
48 output = std::move(decompose.output);
49 }
50
51 // Given an object, return its base object if one exists.
52 std::optional<Object> getBaseObject(const Object &object) {
53 return lower::omp::getBaseObject(object, semaCtx);
54 }
55
56 // Return the iteration variable of the associated loop if any.
57 std::optional<Object> getLoopIterVar() {
58 if (semantics::Symbol *symbol = getIterationVariableSymbol(eval))
59 return Object{symbol, /*designator=*/{}};
60 return std::nullopt;
61 }
62
63 semantics::SemanticsContext &semaCtx;
64 mlir::ModuleOp mod;
65 lower::pft::Evaluation &eval;
66 List<UnitConstruct> output;
67};
68} // namespace
69
70namespace Fortran::lower::omp {
71LLVM_DUMP_METHOD llvm::raw_ostream &operator<<(llvm::raw_ostream &os,
72 const UnitConstruct &uc) {
73 os << llvm::omp::getOpenMPDirectiveName(uc.id, llvm::omp::FallbackVersion);
74 for (auto [index, clause] : llvm::enumerate(First: uc.clauses)) {
75 os << (index == 0 ? '\t' : ' ');
76 os << llvm::omp::getOpenMPClauseName(clause.id);
77 }
78 return os;
79}
80
81ConstructQueue buildConstructQueue(
82 mlir::ModuleOp modOp, Fortran::semantics::SemanticsContext &semaCtx,
83 Fortran::lower::pft::Evaluation &eval, const parser::CharBlock &source,
84 llvm::omp::Directive compound, const List<Clause> &clauses) {
85
86 ConstructDecomposition decompose(modOp, semaCtx, eval, compound, clauses);
87 assert(!decompose.output.empty() && "Construct decomposition failed");
88
89 for (UnitConstruct &uc : decompose.output) {
90 assert(getLeafConstructs(uc.id).empty() && "unexpected compound directive");
91 // If some clauses are left without source information, use the directive's
92 // source.
93 for (auto &clause : uc.clauses)
94 if (clause.source.empty())
95 clause.source = source;
96 }
97
98 return decompose.output;
99}
100
101bool matchLeafSequence(ConstructQueue::const_iterator item,
102 const ConstructQueue &queue,
103 llvm::omp::Directive directive) {
104 llvm::ArrayRef<llvm::omp::Directive> leafDirs =
105 llvm::omp::getLeafConstructsOrSelf(directive);
106
107 for (auto [dir, leaf] :
108 llvm::zip_longest(leafDirs, llvm::make_range(item, queue.end()))) {
109 if (!dir.has_value() || !leaf.has_value())
110 return false;
111
112 if (*dir != leaf->id)
113 return false;
114 }
115
116 return true;
117}
118
119bool isLastItemInQueue(ConstructQueue::const_iterator item,
120 const ConstructQueue &queue) {
121 return std::next(x: item) == queue.end();
122}
123} // namespace Fortran::lower::omp
124

source code of flang/lib/Lower/OpenMP/Decomposer.cpp