MLIR  20.0.0git
Canonicalizer.cpp
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1 //===- Canonicalizer.cpp - Canonicalize MLIR operations -------------------===//
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 // This transformation pass converts operations into their canonical forms by
10 // folding constants, applying operation identity transformations etc.
11 //
12 //===----------------------------------------------------------------------===//
13 
14 #include "mlir/Transforms/Passes.h"
15 
16 #include "mlir/Pass/Pass.h"
18 
19 namespace mlir {
20 #define GEN_PASS_DEF_CANONICALIZER
21 #include "mlir/Transforms/Passes.h.inc"
22 } // namespace mlir
23 
24 using namespace mlir;
25 
26 namespace {
27 /// Canonicalize operations in nested regions.
28 struct Canonicalizer : public impl::CanonicalizerBase<Canonicalizer> {
29  Canonicalizer() = default;
30  Canonicalizer(const GreedyRewriteConfig &config,
31  ArrayRef<std::string> disabledPatterns,
32  ArrayRef<std::string> enabledPatterns)
33  : config(config) {
34  this->topDownProcessingEnabled = config.useTopDownTraversal;
35  this->enableRegionSimplification = config.enableRegionSimplification;
36  this->maxIterations = config.maxIterations;
37  this->maxNumRewrites = config.maxNumRewrites;
38  this->disabledPatterns = disabledPatterns;
39  this->enabledPatterns = enabledPatterns;
40  }
41 
42  /// Initialize the canonicalizer by building the set of patterns used during
43  /// execution.
44  LogicalResult initialize(MLIRContext *context) override {
45  // Set the config from possible pass options set in the meantime.
46  config.useTopDownTraversal = topDownProcessingEnabled;
47  config.enableRegionSimplification = enableRegionSimplification;
48  config.maxIterations = maxIterations;
49  config.maxNumRewrites = maxNumRewrites;
50 
51  RewritePatternSet owningPatterns(context);
52  for (auto *dialect : context->getLoadedDialects())
53  dialect->getCanonicalizationPatterns(owningPatterns);
55  op.getCanonicalizationPatterns(owningPatterns, context);
56 
57  patterns = std::make_shared<FrozenRewritePatternSet>(
58  std::move(owningPatterns), disabledPatterns, enabledPatterns);
59  return success();
60  }
61  void runOnOperation() override {
62  LogicalResult converged =
63  applyPatternsGreedily(getOperation(), *patterns, config);
64  // Canonicalization is best-effort. Non-convergence is not a pass failure.
65  if (testConvergence && failed(converged))
66  signalPassFailure();
67  }
69  std::shared_ptr<const FrozenRewritePatternSet> patterns;
70 };
71 } // namespace
72 
73 /// Create a Canonicalizer pass.
74 std::unique_ptr<Pass> mlir::createCanonicalizerPass() {
75  return std::make_unique<Canonicalizer>();
76 }
77 
78 /// Creates an instance of the Canonicalizer pass with the specified config.
79 std::unique_ptr<Pass>
81  ArrayRef<std::string> disabledPatterns,
82  ArrayRef<std::string> enabledPatterns) {
83  return std::make_unique<Canonicalizer>(config, disabledPatterns,
84  enabledPatterns);
85 }
This class allows control over how the GreedyPatternRewriteDriver works.
MLIRContext is the top-level object for a collection of MLIR operations.
Definition: MLIRContext.h:60
std::vector< Dialect * > getLoadedDialects()
Return information about all IR dialects loaded in the context.
ArrayRef< RegisteredOperationName > getRegisteredOperations()
Return a sorted array containing the information about all registered operations.
This is a "type erased" representation of a registered operation.
Include the generated interface declarations.
const FrozenRewritePatternSet GreedyRewriteConfig config
LogicalResult applyPatternsGreedily(Region &region, const FrozenRewritePatternSet &patterns, GreedyRewriteConfig config=GreedyRewriteConfig(), bool *changed=nullptr)
Rewrite ops in the given region, which must be isolated from above, by repeatedly applying the highes...
const FrozenRewritePatternSet & patterns
std::unique_ptr< Pass > createCanonicalizerPass()
Creates an instance of the Canonicalizer pass, configured with default settings (which can be overrid...