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_FUZZ_TRANSFORMATION_ADD_DEAD_BREAK_H_ 16 #define SOURCE_FUZZ_TRANSFORMATION_ADD_DEAD_BREAK_H_ 17 18 #include <vector> 19 20 #include "source/fuzz/protobufs/spirvfuzz_protobufs.h" 21 #include "source/fuzz/transformation.h" 22 #include "source/fuzz/transformation_context.h" 23 #include "source/opt/ir_context.h" 24 25 namespace spvtools { 26 namespace fuzz { 27 28 class TransformationAddDeadBreak : public Transformation { 29 public: 30 explicit TransformationAddDeadBreak( 31 const protobufs::TransformationAddDeadBreak& message); 32 33 TransformationAddDeadBreak(uint32_t from_block, uint32_t to_block, 34 bool break_condition_value, 35 std::vector<uint32_t> phi_id); 36 37 // - |message_.from_block| must be the id of a block a in the given module. 38 // - |message_.to_block| must be the id of a block b in the given module. 39 // - if |message_.break_condition_value| holds (does not hold) then 40 // OpConstantTrue (OpConstantFalse) must be present in the module 41 // - |message_.phi_ids| must be a list of ids that are all available at 42 // |message_.from_block| 43 // - a and b must be in the same function. 44 // - b must be a merge block. 45 // - a must end with an unconditional branch to some block c. 46 // - replacing this branch with a conditional branch to b or c, with 47 // the boolean constant associated with |message_.break_condition_value| as 48 // the condition, and the ids in |message_.phi_ids| used to extend 49 // any OpPhi instructions at b as a result of the edge from a, must 50 // maintain validity of the module. 51 // In particular, the new branch must not lead to violations of the rule 52 // that a use must be dominated by its definition. 53 bool IsApplicable( 54 opt::IRContext* ir_context, 55 const TransformationContext& transformation_context) const override; 56 57 // Replaces the terminator of a with a conditional branch to b or c. 58 // The boolean constant associated with |message_.break_condition_value| is 59 // used as the condition, and the order of b and c is arranged such that 60 // control is guaranteed to jump to c. 61 void Apply(opt::IRContext* ir_context, 62 TransformationContext* transformation_context) const override; 63 64 std::unordered_set<uint32_t> GetFreshIds() const override; 65 66 protobufs::Transformation ToMessage() const override; 67 68 private: 69 // Returns true if and only if adding an edge from |bb_from| to 70 // |message_.to_block| respects structured control flow. 71 bool AddingBreakRespectsStructuredControlFlow(opt::IRContext* ir_context, 72 opt::BasicBlock* bb_from) const; 73 74 // Used by 'Apply' to actually apply the transformation to the module of 75 // interest, and by 'IsApplicable' to do a dry-run of the transformation on a 76 // cloned module, in order to check that the transformation leads to a valid 77 // module. This is only invoked by 'IsApplicable' after certain basic 78 // applicability checks have been made, ensuring that the invocation of this 79 // method is legal. 80 void ApplyImpl(opt::IRContext* ir_context, 81 const TransformationContext& transformation_context) const; 82 83 protobufs::TransformationAddDeadBreak message_; 84 }; 85 86 } // namespace fuzz 87 } // namespace spvtools 88 89 #endif // SOURCE_FUZZ_TRANSFORMATION_ADD_DEAD_BREAK_H_ 90