xref: /llvm-project/mlir/lib/Dialect/Tensor/Transforms/MergeConsecutiveInsertExtractSlicePatterns.cpp (revision 4c48f016effde67d500fc95290096aec9f3bdb70)
1 //===- MergeConsecutiveInsertExtractSlicePatterns.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/Affine/ViewLikeInterfaceUtils.h"
10 #include "mlir/Dialect/Tensor/IR/Tensor.h"
11 #include "mlir/Dialect/Tensor/Transforms/Transforms.h"
12 #include "mlir/IR/BuiltinTypes.h"
13 #include "mlir/IR/OpDefinition.h"
14 #include "mlir/IR/PatternMatch.h"
15 
16 using namespace mlir;
17 using namespace mlir::tensor;
18 
19 namespace {
20 /// Merges consecutive tensor.extract_slice ops into one.
21 // TODO: move to FoldTensorSubsetOps and unify APIs with FoldMemRefAliasOps.
22 struct MergeConsecutiveExtractSlice : public OpRewritePattern<ExtractSliceOp> {
23   using OpRewritePattern::OpRewritePattern;
24 
25   LogicalResult matchAndRewrite(ExtractSliceOp nextOp,
26                                 PatternRewriter &rewriter) const override {
27     auto prevOp = nextOp.getSource().getDefiningOp<ExtractSliceOp>();
28     if (!prevOp)
29       return failure();
30 
31     SmallVector<OpFoldResult> newOffsets, newSizes, newStrides;
32     if (failed(affine::mergeOffsetsSizesAndStrides(
33             rewriter, nextOp.getLoc(), prevOp, nextOp, prevOp.getDroppedDims(),
34             newOffsets, newSizes, newStrides)))
35       return failure();
36 
37     rewriter.replaceOpWithNewOp<ExtractSliceOp>(nextOp, nextOp.getType(),
38                                                 prevOp.getSource(), newOffsets,
39                                                 newSizes, newStrides);
40     return success();
41   }
42 };
43 
44 /// Merges consecutive tensor.insert_slice ops into one.
45 // TODO: move to FoldTensorSubsetOps and unify APIs with FoldMemRefAliasOps.
46 template <typename OpTy>
47 struct MergeConsecutiveInsertSlice : public OpRewritePattern<OpTy> {
48   using OpRewritePattern<OpTy>::OpRewritePattern;
49 
50   LogicalResult matchAndRewrite(OpTy nextOp,
51                                 PatternRewriter &rewriter) const override {
52     auto prevOp = nextOp.getSource().template getDefiningOp<InsertSliceOp>();
53     if (!prevOp)
54       return failure();
55 
56     if (!prevOp.hasUnitStride() || !nextOp.hasUnitStride())
57       return failure();
58 
59     // The first insert_slice op should be rank reducing to make sure we cover
60     // the full source tensor to be inserted in the second insert_slice op.
61     SliceVerificationResult result =
62         isRankReducedType(prevOp.getDestType(), prevOp.getSourceType());
63     if (result != SliceVerificationResult::Success)
64       return failure();
65 
66     // Dynamic dimensions can pass rank reducing check in the above, e.g,
67     // inserting <?xf32> into <1x?x1xf32>. For such cases we cannot be certain
68     // the dynamic size covers the full tensor.
69     if (!prevOp.getSourceType().hasStaticShape() ||
70         !prevOp.getDestType().hasStaticShape())
71       return failure();
72 
73     rewriter.replaceOpWithNewOp<OpTy>(
74         nextOp, prevOp.getSource(), nextOp.getDest(), nextOp.getMixedOffsets(),
75         nextOp.getMixedSizes(), nextOp.getMixedStrides());
76     return success();
77   }
78 };
79 } // namespace
80 
81 void mlir::tensor::populateMergeConsecutiveInsertExtractSlicePatterns(
82     RewritePatternSet &patterns) {
83   patterns.add<MergeConsecutiveExtractSlice,
84                MergeConsecutiveInsertSlice<InsertSliceOp>,
85                MergeConsecutiveInsertSlice<ParallelInsertSliceOp>>(
86       patterns.getContext());
87 }
88