1 /* Copyright 2018 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_HLO_MODULE_DCE_H_ 17 #define TENSORFLOW_COMPILER_XLA_SERVICE_HLO_MODULE_DCE_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 // HLO pass which removes dead code from computations in the module using 26 // HloModule-scoped analysis (HloLivenessAnalysis). 27 // 28 // Sweeps through live instructions which cross computation boundaries (kWhile), 29 // and removes code at dead shape indices. 30 // 31 class HloModuleDCE : public HloModulePass { 32 public: ~HloModuleDCE()33 ~HloModuleDCE() override {} name()34 absl::string_view name() const override { return "hlo-module-dce"; } 35 36 // Run the pass on the given module. Returns whether the module was changed 37 // (instructions were removed). 38 using HloPassInterface::Run; 39 StatusOr<bool> Run( 40 HloModule* module, 41 const absl::flat_hash_set<absl::string_view>& execution_threads) override; 42 }; 43 44 } // namespace xla 45 46 #endif // TENSORFLOW_COMPILER_XLA_SERVICE_HLO_MODULE_DCE_H_ 47