1 // Copyright (c) 2019 Google LLC 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 #ifndef SOURCE_REDUCE_REMOVE_BLOCK_REDUCTION_OPPORTUNITY_FINDER_H_ 16 #define SOURCE_REDUCE_REMOVE_BLOCK_REDUCTION_OPPORTUNITY_FINDER_H_ 17 18 #include "source/opt/function.h" 19 #include "source/reduce/reduction_opportunity_finder.h" 20 21 namespace spvtools { 22 namespace reduce { 23 24 // A finder of opportunities to remove a block. The optimizer can remove dead 25 // code. However, the reducer needs to be able to remove at a fine-grained 26 // level. 27 class RemoveBlockReductionOpportunityFinder 28 : public ReductionOpportunityFinder { 29 public: 30 RemoveBlockReductionOpportunityFinder() = default; 31 32 ~RemoveBlockReductionOpportunityFinder() override = default; 33 34 std::string GetName() const final; 35 36 std::vector<std::unique_ptr<ReductionOpportunity>> GetAvailableOpportunities( 37 opt::IRContext* context, uint32_t target_function) const final; 38 39 private: 40 // Returns true if the block |bi| in function |function| is a valid 41 // opportunity according to various restrictions. 42 static bool IsBlockValidOpportunity(opt::IRContext* context, 43 opt::Function* function, 44 opt::Function::iterator* bi); 45 46 // Returns true if the instructions (definitions) in block |bi| have no 47 // references, except for references from inside the block itself. 48 static bool BlockInstructionsHaveNoOutsideReferences( 49 opt::IRContext* context, const opt::Function::iterator& bi); 50 }; 51 52 } // namespace reduce 53 } // namespace spvtools 54 55 #endif // SOURCE_REDUCE_REMOVE_BLOCK_REDUCTION_OPPORTUNITY_FINDER_H_ 56