1 //===- OpenMPToLLVM.cpp - conversion from OpenMP to LLVM dialect ----------===//
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 #include "mlir/Conversion/OpenMPToLLVM/ConvertOpenMPToLLVM.h"
10 
11 #include "../PassDetail.h"
12 #include "mlir/Conversion/ArithmeticToLLVM/ArithmeticToLLVM.h"
13 #include "mlir/Conversion/ControlFlowToLLVM/ControlFlowToLLVM.h"
14 #include "mlir/Conversion/FuncToLLVM/ConvertFuncToLLVM.h"
15 #include "mlir/Conversion/FuncToLLVM/ConvertFuncToLLVMPass.h"
16 #include "mlir/Conversion/LLVMCommon/ConversionTarget.h"
17 #include "mlir/Conversion/LLVMCommon/Pattern.h"
18 #include "mlir/Conversion/MemRefToLLVM/MemRefToLLVM.h"
19 #include "mlir/Dialect/LLVMIR/LLVMDialect.h"
20 #include "mlir/Dialect/OpenMP/OpenMPDialect.h"
21 
22 using namespace mlir;
23 
24 namespace {
25 /// A pattern that converts the region arguments in a single-region OpenMP
26 /// operation to the LLVM dialect. The body of the region is not modified and is
27 /// expected to either be processed by the conversion infrastructure or already
28 /// contain ops compatible with LLVM dialect types.
29 template <typename OpType>
30 struct RegionOpConversion : public ConvertOpToLLVMPattern<OpType> {
31   using ConvertOpToLLVMPattern<OpType>::ConvertOpToLLVMPattern;
32 
33   LogicalResult
34   matchAndRewrite(OpType curOp, typename OpType::Adaptor adaptor,
35                   ConversionPatternRewriter &rewriter) const override {
36     auto newOp = rewriter.create<OpType>(
37         curOp.getLoc(), TypeRange(), adaptor.getOperands(), curOp->getAttrs());
38     rewriter.inlineRegionBefore(curOp.region(), newOp.region(),
39                                 newOp.region().end());
40     if (failed(rewriter.convertRegionTypes(&newOp.region(),
41                                            *this->getTypeConverter())))
42       return failure();
43 
44     rewriter.eraseOp(curOp);
45     return success();
46   }
47 };
48 } // namespace
49 
50 void mlir::populateOpenMPToLLVMConversionPatterns(LLVMTypeConverter &converter,
51                                                   RewritePatternSet &patterns) {
52   patterns.add<RegionOpConversion<omp::MasterOp>,
53                RegionOpConversion<omp::ParallelOp>,
54                RegionOpConversion<omp::WsLoopOp>>(converter);
55 }
56 
57 namespace {
58 struct ConvertOpenMPToLLVMPass
59     : public ConvertOpenMPToLLVMBase<ConvertOpenMPToLLVMPass> {
60   void runOnOperation() override;
61 };
62 } // namespace
63 
64 void ConvertOpenMPToLLVMPass::runOnOperation() {
65   auto module = getOperation();
66 
67   // Convert to OpenMP operations with LLVM IR dialect
68   RewritePatternSet patterns(&getContext());
69   LLVMTypeConverter converter(&getContext());
70   arith::populateArithmeticToLLVMConversionPatterns(converter, patterns);
71   cf::populateControlFlowToLLVMConversionPatterns(converter, patterns);
72   populateMemRefToLLVMConversionPatterns(converter, patterns);
73   populateFuncToLLVMConversionPatterns(converter, patterns);
74   populateOpenMPToLLVMConversionPatterns(converter, patterns);
75 
76   LLVMConversionTarget target(getContext());
77   target.addDynamicallyLegalOp<omp::MasterOp, omp::ParallelOp, omp::WsLoopOp>(
78       [&](Operation *op) { return converter.isLegal(&op->getRegion(0)); });
79   target.addLegalOp<omp::TerminatorOp, omp::TaskyieldOp, omp::FlushOp,
80                     omp::BarrierOp, omp::TaskwaitOp>();
81   if (failed(applyPartialConversion(module, target, std::move(patterns))))
82     signalPassFailure();
83 }
84 
85 std::unique_ptr<OperationPass<ModuleOp>> mlir::createConvertOpenMPToLLVMPass() {
86   return std::make_unique<ConvertOpenMPToLLVMPass>();
87 }
88