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_FUZZER_PASS_OUTLINE_FUNCTIONS_H_ 16 #define SOURCE_FUZZ_FUZZER_PASS_OUTLINE_FUNCTIONS_H_ 17 18 #include "source/fuzz/fuzzer_pass.h" 19 20 namespace spvtools { 21 namespace fuzz { 22 23 // A fuzzer pass for outlining single-entry single-exit regions of a control 24 // flow graph into their own functions. 25 class FuzzerPassOutlineFunctions : public FuzzerPass { 26 public: 27 FuzzerPassOutlineFunctions( 28 opt::IRContext* ir_context, TransformationContext* transformation_context, 29 FuzzerContext* fuzzer_context, 30 protobufs::TransformationSequence* transformations); 31 32 void Apply() override; 33 34 // Returns a block suitable to be an entry block for a region that can be 35 // outlined, i.e. a block that is not a loop header and that does not start 36 // with OpPhi or OpVariable. In particular, it returns: 37 // - |entry_block| if it is suitable 38 // - otherwise, a block found by: 39 // - looking for or creating a new preheader, if |entry_block| is a loop 40 // header 41 // - splitting the candidate entry block, if it starts with OpPhi or 42 // OpVariable. 43 // Returns nullptr if a suitable block cannot be found following the 44 // instructions above. 45 opt::BasicBlock* MaybeGetEntryBlockSuitableForOutlining( 46 opt::BasicBlock* entry_block); 47 48 // Returns: 49 // - |exit_block| if it is not a merge block 50 // - the second block obtained by splitting |exit_block|, if |exit_block| is a 51 // merge block. 52 // Assumes that |exit_block| is not a continue target. 53 // The block returned by this function should be suitable to be the exit block 54 // of a region that can be outlined. 55 // Returns nullptr if |exit_block| is a merge block and it cannot be split. 56 opt::BasicBlock* MaybeGetExitBlockSuitableForOutlining( 57 opt::BasicBlock* exit_block); 58 }; 59 60 } // namespace fuzz 61 } // namespace spvtools 62 63 #endif // SOURCE_FUZZ_FUZZER_PASS_OUTLINE_FUNCTIONS_H_ 64