xref: /llvm-project/mlir/lib/Dialect/Linalg/Transforms/SwapExtractSliceWithFillPatterns.cpp (revision c325e978b529e7e899a31cd2693fbc1a676afcf0)
1 //===- SwapExtractSliceWithFillPatterns.cpp -------------------------------===//
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/Dialect/Linalg/Transforms/Transforms.h"
10 #include "mlir/IR/PatternMatch.h"
11 
12 using namespace mlir;
13 using namespace mlir::linalg;
14 
15 /// Swaps tensor.extract_slice(linalg.fill(%cst, %init)) into linalg.fill(%cst,
16 /// tensor.extract_slice(%init)) when the linalg.fill op have no other users.
17 /// This helps to reduce the fill footprint.
18 struct SwapExtractSliceOfFill final
19     : public OpRewritePattern<tensor::ExtractSliceOp> {
20   using OpRewritePattern::OpRewritePattern;
21 
matchAndRewriteSwapExtractSliceOfFill22   LogicalResult matchAndRewrite(tensor::ExtractSliceOp extractOp,
23                                 PatternRewriter &rewriter) const override {
24     auto fillOp = extractOp.getSource().getDefiningOp<FillOp>();
25     if (!fillOp || !fillOp->hasOneUse())
26       return failure();
27 
28     auto newExtractOp = rewriter.create<tensor::ExtractSliceOp>(
29         extractOp.getLoc(), extractOp.getType(), fillOp.getOutputs()[0],
30         extractOp.getMixedOffsets(), extractOp.getMixedSizes(),
31         extractOp.getMixedStrides());
32     rewriter.replaceOpWithNewOp<FillOp>(extractOp, fillOp.getInputs(),
33                                         ValueRange{newExtractOp.getResult()});
34     return success();
35   }
36 };
37 
populateSwapExtractSliceWithFillPatterns(RewritePatternSet & patterns)38 void mlir::linalg::populateSwapExtractSliceWithFillPatterns(
39     RewritePatternSet &patterns) {
40   patterns.add<SwapExtractSliceOfFill>(patterns.getContext());
41 }
42