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