1/* Copyright 2016 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_COMPILER_XLA_SERVICE_HLO_SCHEDULING_H_
17#define TENSORFLOW_COMPILER_XLA_SERVICE_HLO_SCHEDULING_H_
18
19#include <vector>
20
21#include "tensorflow/compiler/xla/service/hlo_instruction.h"
22#include "tensorflow/compiler/xla/service/hlo_module.h"
23#include "tensorflow/compiler/xla/service/hlo_ordering.h"
24#include "tensorflow/compiler/xla/service/logical_buffer.h"
25#include "tensorflow/compiler/xla/statusor.h"
26#include "tensorflow/compiler/xla/types.h"
27
28namespace xla {
29
30// Returns the minimum memory required to compute the given module sequence,
31// assuming no fragmentation.
32StatusOr<int64> MinimumMemoryForSequence(
33    const SequentialHloOrdering::HloModuleSequence& module_sequence,
34    const LogicalBuffer::SizeFunction& size_function);
35
36enum class SchedulerAlgorithm {
37  kListSchedule,
38  kDfsSchedule,
39
40  // Selects the available scheduler algorithm that had the minimum memory in
41  // the resulting sequence (a la MinimumMemoryForSequence).
42  kAuto,
43};
44
45// Returns an HloModuleSequence which seeks to minimize the memory required for
46// the computation. size_function is the function returning the number of bytes
47// required for a LogicalBuffer.
48StatusOr<SequentialHloOrdering::HloModuleSequence>
49CreateMemoryMinimizingSequence(
50    const HloModule& module, const LogicalBuffer::SizeFunction& size_function,
51    SchedulerAlgorithm algorithm = SchedulerAlgorithm::kAuto);
52
53// Overload of above that computes the sequence for a single computation.
54StatusOr<std::vector<const HloInstruction*>> CreateMemoryMinimizingSequence(
55    const HloComputation& computation,
56    const LogicalBuffer::SizeFunction& size_function,
57    SchedulerAlgorithm algorithm = SchedulerAlgorithm::kAuto);
58
59}  // namespace xla
60
61#endif  // TENSORFLOW_COMPILER_XLA_SERVICE_HLO_SCHEDULING_H_
62