SPIRV-Tools/source/fuzz/transformation_invert_comparison_operator.cpp
2020-07-03 17:37:32 +01:00

143 lines
4.6 KiB
C++

// Copyright (c) 2020 Vasyl Teliman
//
// 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/transformation_invert_comparison_operator.h"
#include <utility>
#include "source/fuzz/fuzzer_util.h"
namespace spvtools {
namespace fuzz {
TransformationInvertComparisonOperator::TransformationInvertComparisonOperator(
protobufs::TransformationInvertComparisonOperator message)
: message_(std::move(message)) {}
TransformationInvertComparisonOperator::TransformationInvertComparisonOperator(
uint32_t operator_id, uint32_t fresh_id) {
message_.set_operator_id(operator_id);
message_.set_fresh_id(fresh_id);
}
bool TransformationInvertComparisonOperator::IsApplicable(
opt::IRContext* ir_context, const TransformationContext& /*unused*/) const {
// |message_.operator_id| must be valid and inversion must be supported for
// it.
auto* inst = ir_context->get_def_use_mgr()->GetDef(message_.operator_id());
if (!inst || !IsInversionSupported(inst->opcode())) {
return false;
}
// Check that we can insert negation instruction.
auto* block = ir_context->get_instr_block(inst);
assert(block && "Instruction must have a basic block");
auto iter = fuzzerutil::GetIteratorForInstruction(block, inst);
++iter;
assert(iter != block->end() && "Instruction can't be the last in the block");
assert(fuzzerutil::CanInsertOpcodeBeforeInstruction(SpvOpLogicalNot, iter) &&
"Can't insert negation after comparison operator");
// |message_.fresh_id| must be fresh.
return fuzzerutil::IsFreshId(ir_context, message_.fresh_id());
}
void TransformationInvertComparisonOperator::Apply(
opt::IRContext* ir_context, TransformationContext* /*unused*/) const {
auto* inst = ir_context->get_def_use_mgr()->GetDef(message_.operator_id());
assert(inst && "Result id of an operator is invalid");
// Insert negation after |inst|.
auto iter = fuzzerutil::GetIteratorForInstruction(
ir_context->get_instr_block(inst), inst);
++iter;
iter.InsertBefore(MakeUnique<opt::Instruction>(
ir_context, SpvOpLogicalNot, inst->type_id(), inst->result_id(),
opt::Instruction::OperandList{
{SPV_OPERAND_TYPE_ID, {message_.fresh_id()}}}));
// Change the result id of the original operator to |fresh_id|.
inst->SetResultId(message_.fresh_id());
// Invert the operator.
inst->SetOpcode(InvertOpcode(inst->opcode()));
fuzzerutil::UpdateModuleIdBound(ir_context, message_.fresh_id());
ir_context->InvalidateAnalysesExceptFor(
opt::IRContext::Analysis::kAnalysisNone);
}
bool TransformationInvertComparisonOperator::IsInversionSupported(
SpvOp opcode) {
switch (opcode) {
case SpvOpSGreaterThan:
case SpvOpSGreaterThanEqual:
case SpvOpSLessThan:
case SpvOpSLessThanEqual:
case SpvOpUGreaterThan:
case SpvOpUGreaterThanEqual:
case SpvOpULessThan:
case SpvOpULessThanEqual:
case SpvOpIEqual:
case SpvOpINotEqual:
return true;
default:
return false;
}
}
SpvOp TransformationInvertComparisonOperator::InvertOpcode(SpvOp opcode) {
assert(IsInversionSupported(opcode) && "Inversion must be supported");
switch (opcode) {
case SpvOpSGreaterThan:
return SpvOpSLessThanEqual;
case SpvOpSGreaterThanEqual:
return SpvOpSLessThan;
case SpvOpSLessThan:
return SpvOpSGreaterThanEqual;
case SpvOpSLessThanEqual:
return SpvOpSGreaterThan;
case SpvOpUGreaterThan:
return SpvOpULessThanEqual;
case SpvOpUGreaterThanEqual:
return SpvOpULessThan;
case SpvOpULessThan:
return SpvOpUGreaterThanEqual;
case SpvOpULessThanEqual:
return SpvOpUGreaterThan;
case SpvOpIEqual:
return SpvOpINotEqual;
case SpvOpINotEqual:
return SpvOpIEqual;
default:
// The program will fail in the debug mode because of the assertion
// at the beginning of the function.
return SpvOpNop;
}
}
protobufs::Transformation TransformationInvertComparisonOperator::ToMessage()
const {
protobufs::Transformation result;
*result.mutable_invert_comparison_operator() = message_;
return result;
}
} // namespace fuzz
} // namespace spvtools