| // Copyright (c) 2017 Google Inc. |
| // |
| // Licensed under the Apache License, Version 2.0 (the "License"); |
| // you may not use this file except in compliance with the License. |
| // You may obtain a copy of the License at |
| // |
| // http://www.apache.org/licenses/LICENSE-2.0 |
| // |
| // Unless required by applicable law or agreed to in writing, software |
| // distributed under the License is distributed on an "AS IS" BASIS, |
| // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| // See the License for the specific language governing permissions and |
| // limitations under the License. |
| |
| #ifndef LIBSPIRV_OPT_MERGE_RETURN_PASS_H_ |
| #define LIBSPIRV_OPT_MERGE_RETURN_PASS_H_ |
| |
| #include "basic_block.h" |
| #include "function.h" |
| #include "pass.h" |
| |
| #include <vector> |
| |
| namespace spvtools { |
| namespace opt { |
| |
| // Documented in optimizer.hpp |
| class MergeReturnPass : public Pass { |
| public: |
| MergeReturnPass() = default; |
| const char* name() const override { return "merge-return-pass"; } |
| Status Process(ir::IRContext*) override; |
| |
| ir::IRContext::Analysis GetPreservedAnalyses() override { |
| return ir::IRContext::kAnalysisDefUse; |
| } |
| |
| private: |
| // Returns all BasicBlocks terminated by OpReturn or OpReturnValue in |
| // |function|. |
| std::vector<ir::BasicBlock*> CollectReturnBlocks(ir::Function* function); |
| |
| // Returns |true| if returns were merged, |false| otherwise. |
| // |
| // Creates a new basic block with a single return. If |function| returns a |
| // value, a phi node is created to select the correct value to return. |
| // Replaces old returns with an unconditional branch to the new block. |
| bool MergeReturnBlocks(ir::Function* function, |
| const std::vector<ir::BasicBlock*>& returnBlocks); |
| }; |
| |
| } // namespace opt |
| } // namespace spvtools |
| |
| #endif // LIBSPIRV_OPT_MERGE_RETURN_PASS_H_ |