1 /* Copyright 2017 The TensorFlow Authors. All Rights Reserved.
2 
3 Licensed under the Apache License, Version 2.0 (the "License");
4 you may not use this file except in compliance with the License.
5 You may obtain a copy of the License at
6 
7     http://www.apache.org/licenses/LICENSE-2.0
8 
9 Unless required by applicable law or agreed to in writing, software
10 distributed under the License is distributed on an "AS IS" BASIS,
11 WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
12 See the License for the specific language governing permissions and
13 limitations under the License.
14 ==============================================================================*/
15 
16 #ifndef TENSORFLOW_COMPILER_XLA_SERVICE_TUPLE_SIMPLIFIER_H_
17 #define TENSORFLOW_COMPILER_XLA_SERVICE_TUPLE_SIMPLIFIER_H_
18 
19 #include <utility>
20 
21 #include "tensorflow/compiler/xla/service/hlo_module.h"
22 #include "tensorflow/compiler/xla/service/hlo_pass_interface.h"
23 
24 namespace xla {
25 
26 // A pass which simplifies patterns of Tuple and GetTupleElement instructions in
27 // the module.
28 class TupleSimplifier : public HloModulePass {
29  public:
TupleSimplifier()30   TupleSimplifier() : TupleSimplifier(/*exclude_entry_computation=*/false) {}
31   explicit TupleSimplifier(bool exclude_entry_computation);
~TupleSimplifier()32   ~TupleSimplifier() override {}
name()33   absl::string_view name() const override { return "tuple-simplifier"; }
34 
35   // Run tuple simplification on the given computation. Returns whether the
36   // computation was changed.
37   StatusOr<bool> Run(HloModule* module) override;
38 
39  private:
40   // When set, this pipeline stage will perform optimization of all computations
41   // apart from the module's entry computation. This is used by Graphcore's
42   // backend.
43   bool exclude_entry_computation_;
44 };
45 
46 }  // namespace xla
47 
48 #endif  // TENSORFLOW_COMPILER_XLA_SERVICE_TUPLE_SIMPLIFIER_H_
49