1 /* Copyright 2021 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_ALL_REDUCE_REASSOCIATE_H_ 17 #define TENSORFLOW_COMPILER_XLA_SERVICE_ALL_REDUCE_REASSOCIATE_H_ 18 19 #include "tensorflow/compiler/xla/service/hlo_module.h" 20 #include "tensorflow/compiler/xla/service/hlo_pass_interface.h" 21 #include "tensorflow/compiler/xla/statusor.h" 22 23 namespace xla { 24 25 // A pass that reassociates all-reduce feeding into compatible elementwise 26 // operations. As an example: add(all-reduce(x), all-reduce(y)) will be replaced 27 // with all-reduce(add(x,y)). Mathematically, this is replacing 28 // add(x0, x1, ... xk) + add(y0, y1, ... yk) with 29 // add((x0+y0), (x1+y), ... (xk+yk) 30 // 31 // i.e., reassociating the reduction operation. 32 33 class AllReduceReassociate : public HloModulePass { 34 public: name()35 absl::string_view name() const override { return "all-reduce-reassociate"; } 36 37 using HloPassInterface::Run; 38 StatusOr<bool> Run( 39 HloModule* module, 40 const absl::flat_hash_set<absl::string_view>& execution_threads) override; 41 }; 42 43 } // namespace xla 44 45 #endif // TENSORFLOW_COMPILER_XLA_SERVICE_ALL_REDUCE_REASSOCIATE_H_ 46