0f8a6b7d03
This is intended as a fast pattern rewrite driver for the cases when a simple walk gets the job done but we would still want to implement it in terms of rewrite patterns (that can be used with the greedy pattern rewrite driver downstream). The new driver is inspired by the discussion in https://github.com/llvm/llvm-project/pull/112454 and the LLVM Dev presentation from @matthias-springer earlier this week. This limitation comes with some limitations: * It does not repeat until a fixpoint or revisit ops modified in place or newly created ops. In general, it only walks forward (in the post-order). * `matchAndRewrite` can only erase the matched op or its descendants. This is verified under expensive checks. * It does not perform folding / DCE. We could probably relax some of these in the future without sacrificing too much performance.
38 lines
1.5 KiB
C++
38 lines
1.5 KiB
C++
//===- WALKPATTERNREWRITEDRIVER.h - Walk Pattern Rewrite Driver -*- C++ -*-===//
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//
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// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
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// See https://llvm.org/LICENSE.txt for license information.
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// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
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//
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//===----------------------------------------------------------------------===//
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//
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// Declares a helper function to walk the given op and apply rewrite patterns.
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//
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//===----------------------------------------------------------------------===//
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#ifndef MLIR_TRANSFORMS_WALKPATTERNREWRITEDRIVER_H_
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#define MLIR_TRANSFORMS_WALKPATTERNREWRITEDRIVER_H_
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#include "mlir/IR/Visitors.h"
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#include "mlir/Rewrite/FrozenRewritePatternSet.h"
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namespace mlir {
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/// A fast walk-based pattern rewrite driver. Rewrites ops nested under the
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/// given operation by walking it and applying the highest benefit patterns.
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/// This rewriter *does not* wait until a fixpoint is reached and *does not*
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/// visit modified or newly replaced ops. Also *does not* perform folding or
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/// dead-code elimination.
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///
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/// This is intended as the simplest and most lightweight pattern rewriter in
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/// cases when a simple walk gets the job done.
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///
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/// Note: Does not apply patterns to the given operation itself.
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void walkAndApplyPatterns(Operation *op,
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const FrozenRewritePatternSet &patterns,
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RewriterBase::Listener *listener = nullptr);
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} // namespace mlir
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#endif // MLIR_TRANSFORMS_WALKPATTERNREWRITEDRIVER_H_
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