1/* Copyright 2022 The TensorFlow Authors. All Rights Reserved.
2
3Licensed under the Apache License, Version 2.0 (the "License");
4you may not use this file except in compliance with the License.
5You may obtain a copy of the License at
6
7 http://www.apache.org/licenses/LICENSE-2.0
8
9Unless required by applicable law or agreed to in writing, software
10distributed under the License is distributed on an "AS IS" BASIS,
11WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
12See the License for the specific language governing permissions and
13limitations under the License.
14==============================================================================*/
15
16#ifndef TENSORFLOW_DTENSOR_MLIR_SPARSE_EXPANDER_H_
17#define TENSORFLOW_DTENSOR_MLIR_SPARSE_EXPANDER_H_
18
19#include <string>
20
21#include "absl/container/flat_hash_map.h"
22#include "mlir/IR/Builders.h" // from @llvm-project
23#include "mlir/IR/Operation.h" // from @llvm-project
24#include "mlir/IR/UseDefLists.h" // from @llvm-project
25#include "tensorflow/core/framework/registration/registration.h"
26#include "tensorflow/dtensor/cc/dstatus.h"
27
28namespace tensorflow {
29namespace dtensor {
30
31// Base class for handling Sparse expansion of a MLIR TF Operation.
32// Note that an op will only go through Sparse Expansion only if it has
33// any sparse input tensors.
34class SparseExpanderBase {
35 public:
36 virtual ~SparseExpanderBase() {}
37
38 // Converts `op` to a Sparse expanded form. Sparse expansion logic is
39 // a function of op type and op's operand type.
40 // Must return the `op` that is expanded as the final return value.
41 //
42 // An op has a SparseTensor operand if the defining op of that operand
43 // is a SparseToDenseOp.
44 virtual StatusOr<mlir::Operation*> ExpandOp(mlir::Operation* op) = 0;
45};
46
47// Computes the Sparse expansion for `op`.
48Status RunSparseExpansion(mlir::Operation* op, mlir::Operation** output);
49
50// A registry of sparse SPMD expanders. This map is statically stored and
51// initialized with all the registered sparse SPMD expanders.
52class SparseExpanderRegistry {
53 public:
54 ~SparseExpanderRegistry() = default;
55
56 // A singleton available at startup.
57 static SparseExpanderRegistry* Global();
58
59 // Returns the sparse expansion for the given operation (or nullptr if no
60 // expansion has been registered).
61 SparseExpanderBase* GetSparseExpansionFnForOp(mlir::Operation* op);
62
63 // Registers a sparse expander for the provided opName.
64 InitOnStartupMarker RegisterSparseExpansionFn(
65 std::string opName, std::unique_ptr<SparseExpanderBase> prop);
66
67 private:
68 absl::flat_hash_map<std::string, std::unique_ptr<SparseExpanderBase>>
69 op_to_sparse_expansion_fn_map_;
70};
71
72#define REGISTER_SPARSE(name, op, prop, ...) \
73 static ::tensorflow::InitOnStartupMarker const spmd_##name = \
74 InitOnStartupMarker{} \
75 << SparseExpanderRegistry::Global()->RegisterSparseExpansionFn( \
76 mlir::op ::getOperationName().str(), \
77 std::make_unique<prop>(__VA_ARGS__))
78
79} // namespace dtensor
80} // namespace tensorflow
81
82#endif // TENSORFLOW_DTENSOR_MLIR_SPARSE_EXPANDER_H_
83