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_OP_EXPANDER_PASS_H_ 17 #define TENSORFLOW_COMPILER_XLA_SERVICE_OP_EXPANDER_PASS_H_ 18 19 #include "tensorflow/compiler/xla/service/hlo_pass_interface.h" 20 21 namespace xla { 22 23 // This pass is an abstract superclass for passes that replace operations that 24 // match a pattern. It is intended to be subclassed, not used directly. 25 // 26 // This pass is useful for legalizing HLO instructions that a particular backend 27 // does not support into other HLO instructions. 28 class OpExpanderPass : public HloModulePass { 29 public: 30 using HloPassInterface::Run; 31 StatusOr<bool> Run( 32 HloModule* module, 33 const absl::flat_hash_set<absl::string_view>& execution_threads) override; 34 35 // extra_filter: Optional extra filtering criteria for matching instructions, 36 // used in conjunction with InstructionMatchesPattern. 37 explicit OpExpanderPass(HloPredicate extra_filter = nullptr) extra_filter_(std::move (extra_filter))38 : extra_filter_(std::move(extra_filter)) {} 39 40 protected: 41 // Returns `true` if `instruction` should be expanded by this pass. 42 virtual bool InstructionMatchesPattern(HloInstruction* instruction) = 0; 43 44 // Returns a replacement for `instruction`, or nullptr if no replacement is 45 // needed (e.g. only the to_apply subcomputation of the instruction was 46 // modified). 47 virtual StatusOr<HloInstruction*> ExpandInstruction( 48 HloInstruction* instruction) = 0; 49 50 HloPredicate extra_filter_; 51 }; 52 53 } // namespace xla 54 55 #endif // TENSORFLOW_COMPILER_XLA_SERVICE_OP_EXPANDER_PASS_H_ 56