source/fuzz/fuzzer_pass_adjust_branch_weights.cpp

   1 // Copyright (c) 2020 André Perez Maselco
   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 #include "source/fuzz/fuzzer_pass_adjust_branch_weights.h"
  16
  17 #include "source/fuzz/fuzzer_util.h"
  18 #include "source/fuzz/instruction_descriptor.h"
  19 #include "source/fuzz/transformation_adjust_branch_weights.h"
  20
  21 namespace spvtools {
  22 namespace fuzz {
  23
  24 FuzzerPassAdjustBranchWeights::FuzzerPassAdjustBranchWeights(
  25     opt::IRContext* ir_context, TransformationContext* transformation_context,
  26     FuzzerContext* fuzzer_context,
  27     protobufs::TransformationSequence* transformations,
  28     bool ignore_inapplicable_transformations)
  29     : FuzzerPass(ir_context, transformation_context, fuzzer_context,
  30                  transformations, ignore_inapplicable_transformations) {}
  31
  32 void FuzzerPassAdjustBranchWeights::Apply() {
  33   // For all OpBranchConditional instructions,
  34   // randomly applies the transformation.
  35   GetIRContext()->module()->ForEachInst([this](opt::Instruction* instruction) {
  36     if (instruction->opcode() == spv::Op::OpBranchConditional &&
  37         GetFuzzerContext()->ChoosePercentage(
  38             GetFuzzerContext()->GetChanceOfAdjustingBranchWeights())) {
  39       ApplyTransformation(TransformationAdjustBranchWeights(
  40           MakeInstructionDescriptor(GetIRContext(), instruction),
  41           GetFuzzerContext()->GetRandomBranchWeights()));
  42     }
  43   });
  44 }
  45
  46 }  // namespace fuzz
  47 }  // namespace spvtools