SPIRV-Tools/source/fuzz/fuzzer_pass_adjust_selection_controls.cpp

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// Copyright (c) 2019 Google LLC
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
#include "source/fuzz/fuzzer_pass_adjust_selection_controls.h"
#include "source/fuzz/transformation_set_selection_control.h"
namespace spvtools {
namespace fuzz {
FuzzerPassAdjustSelectionControls::FuzzerPassAdjustSelectionControls(
opt::IRContext* ir_context, FactManager* fact_manager,
FuzzerContext* fuzzer_context,
protobufs::TransformationSequence* transformations)
: FuzzerPass(ir_context, fact_manager, fuzzer_context, transformations) {}
FuzzerPassAdjustSelectionControls::~FuzzerPassAdjustSelectionControls() =
default;
void FuzzerPassAdjustSelectionControls::Apply() {
// Consider every merge instruction in the module (via looking through all
// functions and blocks).
for (auto& function : *GetIRContext()->module()) {
for (auto& block : function) {
if (auto merge_inst = block.GetMergeInst()) {
// Ignore the instruction if it is not a selection merge.
if (merge_inst->opcode() != SpvOpSelectionMerge) {
continue;
}
// Choose randomly whether to change the selection control for this
// instruction.
if (!GetFuzzerContext()->ChoosePercentage(
GetFuzzerContext()->GetChanceOfAdjustingSelectionControl())) {
continue;
}
// The choices to change the selection control to are the set of valid
// controls, minus the current control.
std::vector<uint32_t> choices;
for (auto control :
{SpvSelectionControlMaskNone, SpvSelectionControlFlattenMask,
SpvSelectionControlDontFlattenMask}) {
if (control == merge_inst->GetSingleWordOperand(1)) {
continue;
}
choices.push_back(control);
}
// Apply the transformation and add it to the output transformation
// sequence.
TransformationSetSelectionControl transformation(
block.id(), choices[GetFuzzerContext()->RandomIndex(choices)]);
assert(transformation.IsApplicable(GetIRContext(), *GetFactManager()) &&
"Transformation should be applicable by construction.");
transformation.Apply(GetIRContext(), GetFactManager());
*GetTransformations()->add_transformation() =
transformation.ToMessage();
}
}
}
}
} // namespace fuzz
} // namespace spvtools