| 1 | //===- RewriteAsConstant.cpp - Patterns to rewrite tensor ops as constants ===// |
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| 2 | // |
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| 3 | // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. |
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| 4 | // See https://llvm.org/LICENSE.txt for license information. |
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| 5 | // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception |
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| 6 | // |
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| 7 | //===----------------------------------------------------------------------===// |
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| 8 | // |
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| 9 | #include "mlir/Dialect/Tensor/IR/Tensor.h" |
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| 10 | #include "mlir/Dialect/Tensor/Transforms/Transforms.h" |
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| 11 | #include "mlir/IR/Matchers.h" |
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| 12 | #include "mlir/IR/PatternMatch.h" |
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| 13 | |
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| 14 | using namespace mlir; |
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| 15 | using namespace mlir::tensor; |
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| 16 | |
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| 17 | namespace { |
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| 18 | |
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| 19 | /// Rewrite tensor.generate with arith.constant if the yielded value is a |
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| 20 | /// constant and the tensor type is static. |
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| 21 | struct GenerateToConstant : public OpRewritePattern<GenerateOp> { |
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| 22 | using OpRewritePattern<GenerateOp>::OpRewritePattern; |
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| 23 | |
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| 24 | LogicalResult matchAndRewrite(GenerateOp generateOp, |
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| 25 | PatternRewriter &rewriter) const override { |
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| 26 | auto tensorType = |
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| 27 | llvm::cast<RankedTensorType>(generateOp.getResult().getType()); |
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| 28 | if (!tensorType.hasStaticShape()) |
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| 29 | return failure(); |
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| 30 | auto terminatorOp = |
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| 31 | cast<tensor::YieldOp>(generateOp.getBody().front().getTerminator()); |
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| 32 | Attribute attr; |
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| 33 | if (!matchPattern(terminatorOp.getValue(), m_Constant(bind_value: &attr))) |
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| 34 | return failure(); |
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| 35 | Operation *constantOp = |
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| 36 | rewriter.getContext() |
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| 37 | ->getLoadedDialect<TensorDialect>() |
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| 38 | ->materializeConstant(rewriter, |
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| 39 | DenseElementsAttr::get(tensorType, attr), |
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| 40 | tensorType, generateOp->getLoc()); |
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| 41 | if (!constantOp) |
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| 42 | return failure(); |
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| 43 | rewriter.replaceOp(generateOp, constantOp->getResults()); |
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| 44 | return success(); |
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| 45 | } |
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| 46 | }; |
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| 47 | |
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| 48 | } // namespace |
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| 49 | |
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| 50 | void mlir::tensor::populateRewriteAsConstantPatterns( |
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| 51 | RewritePatternSet &patterns) { |
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| 52 | patterns.add<GenerateToConstant>(arg: patterns.getContext()); |
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| 53 | } |
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| 54 | |
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