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_OPT_DESC_SROA_H_ 16 #define SOURCE_OPT_DESC_SROA_H_ 17 18 #include <cstdio> 19 #include <memory> 20 #include <queue> 21 #include <unordered_map> 22 #include <unordered_set> 23 #include <vector> 24 25 #include "source/opt/function.h" 26 #include "source/opt/pass.h" 27 #include "source/opt/type_manager.h" 28 29 namespace spvtools { 30 namespace opt { 31 32 // Documented in optimizer.hpp 33 class DescriptorScalarReplacement : public Pass { 34 public: DescriptorScalarReplacement()35 DescriptorScalarReplacement() {} 36 name()37 const char* name() const override { return "descriptor-scalar-replacement"; } 38 39 Status Process() override; 40 GetPreservedAnalyses()41 IRContext::Analysis GetPreservedAnalyses() override { 42 return IRContext::kAnalysisDefUse | 43 IRContext::kAnalysisInstrToBlockMapping | 44 IRContext::kAnalysisCombinators | IRContext::kAnalysisCFG | 45 IRContext::kAnalysisConstants | IRContext::kAnalysisTypes; 46 } 47 48 private: 49 // Returns true if |var| is an OpVariable instruction that represents a 50 // descriptor array. These are the variables that we want to replace. 51 bool IsCandidate(Instruction* var); 52 53 // Replaces all references to |var| by new variables, one for each element of 54 // the array |var|. The binding for the new variables corresponding to 55 // element i will be the binding of |var| plus i. Returns true if successful. 56 bool ReplaceCandidate(Instruction* var); 57 58 // Replaces the base address |var| in the OpAccessChain or 59 // OpInBoundsAccessChain instruction |use| by the variable that the access 60 // chain accesses. The first index in |use| must be an |OpConstant|. Returns 61 // |true| if successful. 62 bool ReplaceAccessChain(Instruction* var, Instruction* use); 63 64 // Replaces the given compososite variable |var| loaded by OpLoad |value| with 65 // replacement variables, one for each component that's accessed in the 66 // shader. Assumes that |value| is only used by OpCompositeExtract 67 // instructions, one index at a time. Returns true on success, and false 68 // otherwise. 69 bool ReplaceLoadedValue(Instruction* var, Instruction* value); 70 71 // Replaces the given OpCompositeExtract |extract| and all of its references 72 // with an OpLoad of a replacement variable. |var| is the variable with 73 // composite type whose value is being used by |extract|. Assumes that 74 // |extract| is extracting one index only. Returns true on success, and false 75 // otherwise. 76 bool ReplaceCompositeExtract(Instruction* var, Instruction* extract); 77 78 // Returns the id of the variable that will be used to replace the |idx|th 79 // element of |var|. The variable is created if it has not already been 80 // created. 81 uint32_t GetReplacementVariable(Instruction* var, uint32_t idx); 82 83 // Returns the id of a new variable that can be used to replace the |idx|th 84 // element of |var|. 85 uint32_t CreateReplacementVariable(Instruction* var, uint32_t idx); 86 87 // Returns the number of bindings used by the given |type_id|. 88 // All types are considered to use 1 binding slot, except: 89 // 1- A pointer type consumes as many binding numbers as its pointee. 90 // 2- An array of size N consumes N*M binding numbers, where M is the number 91 // of bindings used by each array element. 92 // 3- The number of bindings consumed by a structure is the sum of the 93 // bindings used by its members. 94 uint32_t GetNumBindingsUsedByType(uint32_t type_id); 95 96 // Returns true if |type| is a type that could be used for a structured buffer 97 // as opposed to a type that would be used for a structure of resource 98 // descriptors. 99 bool IsTypeOfStructuredBuffer(const Instruction* type) const; 100 101 // A map from an OpVariable instruction to the set of variables that will be 102 // used to replace it. The entry |replacement_variables_[var][i]| is the id of 103 // a variable that will be used in the place of the the ith element of the 104 // array |var|. If the entry is |0|, then the variable has not been 105 // created yet. 106 std::map<Instruction*, std::vector<uint32_t>> replacement_variables_; 107 }; 108 109 } // namespace opt 110 } // namespace spvtools 111 112 #endif // SOURCE_OPT_DESC_SROA_H_ 113