1 files changed, 45 insertions, 0 deletions
diff --git a/mlir/lib/Transforms/Canonicalizer.cpp b/mlir/lib/Transforms/Canonicalizer.cpp
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index 00000000000..5b3a1eb1cf3
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+++ b/mlir/lib/Transforms/Canonicalizer.cpp
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+//===- Canonicalizer.cpp - Canonicalize MLIR operations -------------------===//
+//
+// Part of the MLIR Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+//
+// This transformation pass converts operations into their canonical forms by
+// folding constants, applying operation identity transformations etc.
+//
+//===----------------------------------------------------------------------===//
+
+#include "mlir/IR/MLIRContext.h"
+#include "mlir/IR/PatternMatch.h"
+#include "mlir/Pass/Pass.h"
+#include "mlir/Transforms/Passes.h"
+using namespace mlir;
+
+namespace {
+/// Canonicalize operations in nested regions.
+struct Canonicalizer : public OperationPass<Canonicalizer> {
+  void runOnOperation() override {
+    OwningRewritePatternList patterns;
+
+    // TODO: Instead of adding all known patterns from the whole system lazily
+    // add and cache the canonicalization patterns for ops we see in practice
+    // when building the worklist.  For now, we just grab everything.
+    auto *context = &getContext();
+    for (auto *op : context->getRegisteredOperations())
+      op->getCanonicalizationPatterns(patterns, context);
+
+    Operation *op = getOperation();
+    applyPatternsGreedily(op->getRegions(), patterns);
+  }
+};
+} // end anonymous namespace
+
+/// Create a Canonicalizer pass.
+std::unique_ptr<Pass> mlir::createCanonicalizerPass() {
+  return std::make_unique<Canonicalizer>();
+}
+
+static PassRegistration<Canonicalizer> pass("canonicalize",
+                                            "Canonicalize operations");