1 // Copyright (c) 2017 Google Inc. 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 #include "source/opt/eliminate_dead_functions_pass.h" 16 #include "source/opt/eliminate_dead_functions_util.h" 17 18 #include <unordered_set> 19 20 #include "source/opt/ir_context.h" 21 22 namespace spvtools { 23 namespace opt { 24 Process()25Pass::Status EliminateDeadFunctionsPass::Process() { 26 // Identify live functions first. Those that are not live 27 // are dead. 28 std::unordered_set<const Function*> live_function_set; 29 ProcessFunction mark_live = [&live_function_set](Function* fp) { 30 live_function_set.insert(fp); 31 return false; 32 }; 33 context()->ProcessReachableCallTree(mark_live); 34 35 bool modified = false; 36 for (auto funcIter = get_module()->begin(); 37 funcIter != get_module()->end();) { 38 if (live_function_set.count(&*funcIter) == 0) { 39 modified = true; 40 funcIter = 41 eliminatedeadfunctionsutil::EliminateFunction(context(), &funcIter); 42 } else { 43 ++funcIter; 44 } 45 } 46 47 return modified ? Pass::Status::SuccessWithChange 48 : Pass::Status::SuccessWithoutChange; 49 } 50 51 } // namespace opt 52 } // namespace spvtools 53