1 // Copyright (c) 2018 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_REDUCTION_PASS_H_ 16 #define SOURCE_REDUCE_REDUCTION_PASS_H_ 17 18 #include <limits> 19 20 #include "source/opt/ir_context.h" 21 #include "source/reduce/reduction_opportunity_finder.h" 22 #include "spirv-tools/libspirv.hpp" 23 24 namespace spvtools { 25 namespace reduce { 26 27 // Abstract class representing a reduction pass, which can be repeatedly 28 // invoked to find and apply particular reduction opportunities to a SPIR-V 29 // binary. In the spirit of delta debugging, a pass initially tries to apply 30 // large chunks of reduction opportunities, iterating through available 31 // opportunities at a given granularity. When an iteration over available 32 // opportunities completes, the granularity is reduced and iteration starts 33 // again, until the minimum granularity is reached. 34 class ReductionPass { 35 public: 36 // Constructs a reduction pass with a given target environment, |target_env|, 37 // and a given finder of reduction opportunities, |finder|. ReductionPass(const spv_target_env target_env,std::unique_ptr<ReductionOpportunityFinder> finder)38 explicit ReductionPass(const spv_target_env target_env, 39 std::unique_ptr<ReductionOpportunityFinder> finder) 40 : target_env_(target_env), 41 finder_(std::move(finder)), 42 index_(0), 43 granularity_(std::numeric_limits<uint32_t>::max()) {} 44 45 // Applies the reduction pass to the given binary by applying a "chunk" of 46 // reduction opportunities. Returns the new binary if a chunk was applied; in 47 // this case, before the next call the caller must invoke 48 // NotifyInteresting(...) to indicate whether the new binary is interesting. 49 // Returns an empty vector if there are no more chunks left to apply; in this 50 // case, the index will be reset and the granularity lowered for the next 51 // round. 52 // 53 // If |target_function| is non-zero, only reduction opportunities that 54 // simplify the internals of the function with result id |target_function| 55 // will be applied. 56 std::vector<uint32_t> TryApplyReduction(const std::vector<uint32_t>& binary, 57 uint32_t target_function); 58 59 // Notifies the reduction pass whether the binary returned from 60 // TryApplyReduction is interesting, so that the next call to 61 // TryApplyReduction will avoid applying the same chunk of opportunities. 62 void NotifyInteresting(bool interesting); 63 64 // Sets a consumer to which relevant messages will be directed. 65 void SetMessageConsumer(MessageConsumer consumer); 66 67 // Returns true if the granularity with which reduction opportunities are 68 // applied has reached a minimum. 69 bool ReachedMinimumGranularity() const; 70 71 // Returns the name associated with this reduction pass (based on its 72 // associated finder). 73 std::string GetName() const; 74 75 private: 76 const spv_target_env target_env_; 77 const std::unique_ptr<ReductionOpportunityFinder> finder_; 78 MessageConsumer consumer_; 79 uint32_t index_; 80 uint32_t granularity_; 81 }; 82 83 } // namespace reduce 84 } // namespace spvtools 85 86 #endif // SOURCE_REDUCE_REDUCTION_PASS_H_ 87