xref: /llvm-project/mlir/lib/Conversion/OpenACCToSCF/OpenACCToSCF.cpp (revision 5fcf907b34355980f77d7665a175b05fea7a6b7b)
1 //===- OpenACCToSCF.cpp - OpenACC condition to SCF if conversion ----------===//
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/OpenACCToSCF/ConvertOpenACCToSCF.h"
10 
11 #include "mlir/Dialect/Arith/IR/Arith.h"
12 #include "mlir/Dialect/OpenACC/OpenACC.h"
13 #include "mlir/Dialect/SCF/IR/SCF.h"
14 #include "mlir/IR/Matchers.h"
15 #include "mlir/Pass/Pass.h"
16 #include "mlir/Transforms/DialectConversion.h"
17 
18 namespace mlir {
19 #define GEN_PASS_DEF_CONVERTOPENACCTOSCF
20 #include "mlir/Conversion/Passes.h.inc"
21 } // namespace mlir
22 
23 using namespace mlir;
24 
25 //===----------------------------------------------------------------------===//
26 // Conversion patterns
27 //===----------------------------------------------------------------------===//
28 
29 namespace {
30 /// Pattern to transform the `getIfCond` on operation without region into a
31 /// scf.if and move the operation into the `then` region.
32 template <typename OpTy>
33 class ExpandIfCondition : public OpRewritePattern<OpTy> {
34   using OpRewritePattern<OpTy>::OpRewritePattern;
35 
matchAndRewrite(OpTy op,PatternRewriter & rewriter) const36   LogicalResult matchAndRewrite(OpTy op,
37                                 PatternRewriter &rewriter) const override {
38     // Early exit if there is no condition.
39     if (!op.getIfCond())
40       return failure();
41 
42     IntegerAttr constAttr;
43     if (!matchPattern(op.getIfCond(), m_Constant(&constAttr))) {
44       auto ifOp = rewriter.create<scf::IfOp>(op.getLoc(), TypeRange(),
45                                              op.getIfCond(), false);
46       rewriter.modifyOpInPlace(op, [&]() { op.getIfCondMutable().erase(0); });
47       auto thenBodyBuilder = ifOp.getThenBodyBuilder(rewriter.getListener());
48       thenBodyBuilder.clone(*op.getOperation());
49       rewriter.eraseOp(op);
50     } else {
51       if (constAttr.getInt())
52         rewriter.modifyOpInPlace(op, [&]() { op.getIfCondMutable().erase(0); });
53       else
54         rewriter.eraseOp(op);
55     }
56     return success();
57   }
58 };
59 } // namespace
60 
populateOpenACCToSCFConversionPatterns(RewritePatternSet & patterns)61 void mlir::populateOpenACCToSCFConversionPatterns(RewritePatternSet &patterns) {
62   patterns.add<ExpandIfCondition<acc::EnterDataOp>>(patterns.getContext());
63   patterns.add<ExpandIfCondition<acc::ExitDataOp>>(patterns.getContext());
64   patterns.add<ExpandIfCondition<acc::UpdateOp>>(patterns.getContext());
65 }
66 
67 namespace {
68 struct ConvertOpenACCToSCFPass
69     : public impl::ConvertOpenACCToSCFBase<ConvertOpenACCToSCFPass> {
70   void runOnOperation() override;
71 };
72 } // namespace
73 
runOnOperation()74 void ConvertOpenACCToSCFPass::runOnOperation() {
75   auto op = getOperation();
76   auto *context = op.getContext();
77 
78   RewritePatternSet patterns(context);
79   ConversionTarget target(*context);
80   populateOpenACCToSCFConversionPatterns(patterns);
81 
82   target.addLegalDialect<scf::SCFDialect>();
83   target.addLegalDialect<acc::OpenACCDialect>();
84 
85   target.addDynamicallyLegalOp<acc::EnterDataOp>(
86       [](acc::EnterDataOp op) { return !op.getIfCond(); });
87 
88   target.addDynamicallyLegalOp<acc::ExitDataOp>(
89       [](acc::ExitDataOp op) { return !op.getIfCond(); });
90 
91   target.addDynamicallyLegalOp<acc::UpdateOp>(
92       [](acc::UpdateOp op) { return !op.getIfCond(); });
93 
94   if (failed(applyPartialConversion(op, target, std::move(patterns))))
95     signalPassFailure();
96 }
97 
createConvertOpenACCToSCFPass()98 std::unique_ptr<OperationPass<ModuleOp>> mlir::createConvertOpenACCToSCFPass() {
99   return std::make_unique<ConvertOpenACCToSCFPass>();
100 }
101