| // Copyright (c) 2018 Google LLC |
| // |
| // 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 SOURCE_OPT_REDUCE_LOAD_SIZE_H_ |
| #define SOURCE_OPT_REDUCE_LOAD_SIZE_H_ |
| |
| #include <unordered_map> |
| |
| #include "source/opt/ir_context.h" |
| #include "source/opt/module.h" |
| #include "source/opt/pass.h" |
| |
| namespace spvtools { |
| namespace opt { |
| |
| // See optimizer.hpp for documentation. |
| class ReduceLoadSize : public Pass { |
| public: |
| explicit ReduceLoadSize(double replacement_threshold) |
| : replacement_threshold_(replacement_threshold) {} |
| |
| const char* name() const override { return "reduce-load-size"; } |
| Status Process() override; |
| |
| // Return the mask of preserved Analyses. |
| IRContext::Analysis GetPreservedAnalyses() override { |
| return IRContext::kAnalysisDefUse | |
| IRContext::kAnalysisInstrToBlockMapping | |
| IRContext::kAnalysisCombinators | IRContext::kAnalysisCFG | |
| IRContext::kAnalysisDominatorAnalysis | |
| IRContext::kAnalysisLoopAnalysis | IRContext::kAnalysisNameMap | |
| IRContext::kAnalysisConstants | IRContext::kAnalysisTypes; |
| } |
| |
| private: |
| // Replaces |inst|, which must be an OpCompositeExtract instruction, with |
| // an OpAccessChain and a load if possible. This happens only if it is a load |
| // feeding |inst|. Returns true if the substitution happened. The position |
| // of the new instructions will be in the same place as the load feeding the |
| // extract. |
| bool ReplaceExtract(Instruction* inst); |
| |
| // Returns true if the OpCompositeExtract instruction |inst| should be replace |
| // or not. This is determined by looking at the load that feeds |inst| if |
| // it is a load. |should_replace_cache_| is used to cache the results based |
| // on the load feeding |inst|. |
| bool ShouldReplaceExtract(Instruction* inst); |
| |
| // Threshold to determine whether we have to replace the load or not. If the |
| // ratio of the used components of the load is less than the threshold, we |
| // replace the load. |
| double replacement_threshold_; |
| |
| // Maps the result id of an OpLoad instruction to the result of whether or |
| // not the OpCompositeExtract that use the id should be replaced. |
| std::unordered_map<uint32_t, bool> should_replace_cache_; |
| }; |
| |
| } // namespace opt |
| } // namespace spvtools |
| |
| #endif // SOURCE_OPT_REDUCE_LOAD_SIZE_H_ |