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// Copyright (c) 2020 André Perez Maselco
//
// 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_add_bit_instruction_synonym.h"
#include "source/fuzz/fuzzer_util.h"
#include "source/fuzz/instruction_descriptor.h"
namespace spvtools {
namespace fuzz {
TransformationAddBitInstructionSynonym::TransformationAddBitInstructionSynonym(
protobufs::TransformationAddBitInstructionSynonym message)
: message_(std::move(message)) {}
TransformationAddBitInstructionSynonym::TransformationAddBitInstructionSynonym(
const uint32_t instruction_result_id,
const std::vector<uint32_t>& fresh_ids) {
message_.set_instruction_result_id(instruction_result_id);
*message_.mutable_fresh_ids() =
google::protobuf::RepeatedField<google::protobuf::uint32>(
fresh_ids.begin(), fresh_ids.end());
}
bool TransformationAddBitInstructionSynonym::IsApplicable(
opt::IRContext* ir_context,
const TransformationContext& transformation_context) const {
auto instruction =
ir_context->get_def_use_mgr()->GetDef(message_.instruction_result_id());
// Checks on: only integer operands are supported, instructions are bitwise
// operations only. Signedness of the operands must be the same.
if (!IsInstructionSupported(ir_context, instruction)) {
return false;
}
// TODO(https://github.com/KhronosGroup/SPIRV-Tools/issues/3791):
// This condition could be relaxed if the index exists as another integer
// type.
// All bit indexes must be defined as 32-bit unsigned integers.
uint32_t width = ir_context->get_type_mgr()
->GetType(instruction->type_id())
->AsInteger()
->width();
for (uint32_t i = 0; i < width; i++) {
if (!fuzzerutil::MaybeGetIntegerConstant(ir_context, transformation_context,
{i}, 32, false, false)) {
return false;
}
}
// |message_.fresh_ids.size| must have the exact number of fresh ids required
// to apply the transformation.
if (static_cast<uint32_t>(message_.fresh_ids().size()) !=
GetRequiredFreshIdCount(ir_context, instruction)) {
return false;
}
// All ids in |message_.fresh_ids| must be fresh.
for (uint32_t fresh_id : message_.fresh_ids()) {
if (!fuzzerutil::IsFreshId(ir_context, fresh_id)) {
return false;
}
}
return true;
}
void TransformationAddBitInstructionSynonym::Apply(
opt::IRContext* ir_context,
TransformationContext* transformation_context) const {
auto bit_instruction =
ir_context->get_def_use_mgr()->GetDef(message_.instruction_result_id());
// Use an appropriate helper function to add the new instruction and new
// synonym fact. The helper function should take care of invalidating
// analyses before adding facts.
switch (bit_instruction->opcode()) {
case SpvOpBitwiseOr:
case SpvOpBitwiseXor:
case SpvOpBitwiseAnd:
case SpvOpNot:
AddOpBitwiseOrOpNotSynonym(ir_context, transformation_context,
bit_instruction);
break;
default:
assert(false && "Should be unreachable.");
break;
}
}
bool TransformationAddBitInstructionSynonym::IsInstructionSupported(
opt::IRContext* ir_context, opt::Instruction* instruction) {
// TODO(https://github.com/KhronosGroup/SPIRV-Tools/issues/3557):
// Right now we only support certain operations. When this issue is addressed
// the following conditional can use the function |spvOpcodeIsBit|.
// |instruction| must be defined and must be a supported bit instruction.
if (!instruction || (instruction->opcode() != SpvOpBitwiseOr &&
instruction->opcode() != SpvOpBitwiseXor &&
instruction->opcode() != SpvOpBitwiseAnd &&
instruction->opcode() != SpvOpNot)) {
return false;
}
// TODO(https://github.com/KhronosGroup/SPIRV-Tools/issues/3792):
// Right now, only integer operands are supported.
if (ir_context->get_type_mgr()->GetType(instruction->type_id())->AsVector()) {
return false;
}
if (instruction->opcode() == SpvOpNot) {
auto operand = instruction->GetInOperand(0).words[0];
auto operand_inst = ir_context->get_def_use_mgr()->GetDef(operand);
auto operand_type =
ir_context->get_type_mgr()->GetType(operand_inst->type_id());
auto operand_sign = operand_type->AsInteger()->IsSigned();
auto type_id_sign = ir_context->get_type_mgr()
->GetType(instruction->type_id())
->AsInteger()
->IsSigned();
return operand_sign == type_id_sign;
} else {
// Other BitWise operations that takes two operands.
auto first_operand = instruction->GetInOperand(0).words[0];
auto first_operand_inst =
ir_context->get_def_use_mgr()->GetDef(first_operand);
auto first_operand_type =
ir_context->get_type_mgr()->GetType(first_operand_inst->type_id());
auto first_operand_sign = first_operand_type->AsInteger()->IsSigned();
auto second_operand = instruction->GetInOperand(1).words[0];
auto second_operand_inst =
ir_context->get_def_use_mgr()->GetDef(second_operand);
auto second_operand_type =
ir_context->get_type_mgr()->GetType(second_operand_inst->type_id());
auto second_operand_sign = second_operand_type->AsInteger()->IsSigned();
auto type_id_sign = ir_context->get_type_mgr()
->GetType(instruction->type_id())
->AsInteger()
->IsSigned();
return first_operand_sign == second_operand_sign &&
first_operand_sign == type_id_sign;
}
}
protobufs::Transformation TransformationAddBitInstructionSynonym::ToMessage()
const {
protobufs::Transformation result;
*result.mutable_add_bit_instruction_synonym() = message_;
return result;
}
uint32_t TransformationAddBitInstructionSynonym::GetRequiredFreshIdCount(
opt::IRContext* ir_context, opt::Instruction* bit_instruction) {
// TODO(https://github.com/KhronosGroup/SPIRV-Tools/issues/3557):
// Right now, only certain operations are supported.
switch (bit_instruction->opcode()) {
case SpvOpBitwiseOr:
case SpvOpBitwiseXor:
case SpvOpBitwiseAnd:
case SpvOpNot:
return (2 + bit_instruction->NumInOperands()) *
ir_context->get_type_mgr()
->GetType(bit_instruction->type_id())
->AsInteger()
->width() -
1;
default:
assert(false && "Unsupported bit instruction.");
return 0;
}
}
void TransformationAddBitInstructionSynonym::AddOpBitwiseOrOpNotSynonym(
opt::IRContext* ir_context, TransformationContext* transformation_context,
opt::Instruction* bit_instruction) const {
// Fresh id iterator.
auto fresh_id = message_.fresh_ids().begin();
// |width| is the bit width of operands (8, 16, 32 or 64).
const uint32_t width = ir_context->get_type_mgr()
->GetType(bit_instruction->type_id())
->AsInteger()
->width();
// |count| is the number of bits to be extracted and inserted at a time.
const uint32_t count = fuzzerutil::MaybeGetIntegerConstant(
ir_context, *transformation_context, {1}, 32, false, false);
// |extracted_bit_instructions| is the collection of OpBiwise* or OpNot
// instructions that evaluate the extracted bits. Those ids will be used to
// insert the result bits.
std::vector<uint32_t> extracted_bit_instructions(width);
for (uint32_t i = 0; i < width; i++) {
// |offset| is the current bit index.
uint32_t offset = fuzzerutil::MaybeGetIntegerConstant(
ir_context, *transformation_context, {i}, 32, false, false);
// |bit_extract_ids| are the two extracted bits from the operands.
opt::Instruction::OperandList bit_extract_ids;
// Extracts the i-th bit from operands.
for (auto operand = bit_instruction->begin() + 2;
operand != bit_instruction->end(); operand++) {
auto bit_extract =
opt::Instruction(ir_context, SpvOpBitFieldUExtract,
bit_instruction->type_id(), *fresh_id++,
{{SPV_OPERAND_TYPE_ID, operand->words},
{SPV_OPERAND_TYPE_ID, {offset}},
{SPV_OPERAND_TYPE_ID, {count}}});
bit_instruction->InsertBefore(MakeUnique<opt::Instruction>(bit_extract));
fuzzerutil::UpdateModuleIdBound(ir_context, bit_extract.result_id());
bit_extract_ids.push_back(
{SPV_OPERAND_TYPE_ID, {bit_extract.result_id()}});
}
// Applies |bit_instruction| to the extracted bits.
auto extracted_bit_instruction = opt::Instruction(
ir_context, bit_instruction->opcode(), bit_instruction->type_id(),
*fresh_id++, bit_extract_ids);
bit_instruction->InsertBefore(
MakeUnique<opt::Instruction>(extracted_bit_instruction));
fuzzerutil::UpdateModuleIdBound(ir_context,
extracted_bit_instruction.result_id());
extracted_bit_instructions[i] = extracted_bit_instruction.result_id();
}
// The first two ids in |extracted_bit_instructions| are used to insert the
// first two bits of the result.
uint32_t offset = fuzzerutil::MaybeGetIntegerConstant(
ir_context, *transformation_context, {1}, 32, false, false);
auto bit_insert = opt::Instruction(
ir_context, SpvOpBitFieldInsert, bit_instruction->type_id(), *fresh_id++,
{{SPV_OPERAND_TYPE_ID, {extracted_bit_instructions[0]}},
{SPV_OPERAND_TYPE_ID, {extracted_bit_instructions[1]}},
{SPV_OPERAND_TYPE_ID, {offset}},
{SPV_OPERAND_TYPE_ID, {count}}});
bit_instruction->InsertBefore(MakeUnique<opt::Instruction>(bit_insert));
fuzzerutil::UpdateModuleIdBound(ir_context, bit_insert.result_id());
// Inserts the remaining bits.
for (uint32_t i = 2; i < width; i++) {
offset = fuzzerutil::MaybeGetIntegerConstant(
ir_context, *transformation_context, {i}, 32, false, false);
bit_insert = opt::Instruction(
ir_context, SpvOpBitFieldInsert, bit_instruction->type_id(),
*fresh_id++,
{{SPV_OPERAND_TYPE_ID, {bit_insert.result_id()}},
{SPV_OPERAND_TYPE_ID, {extracted_bit_instructions[i]}},
{SPV_OPERAND_TYPE_ID, {offset}},
{SPV_OPERAND_TYPE_ID, {count}}});
bit_instruction->InsertBefore(MakeUnique<opt::Instruction>(bit_insert));
fuzzerutil::UpdateModuleIdBound(ir_context, bit_insert.result_id());
}
ir_context->InvalidateAnalysesExceptFor(opt::IRContext::kAnalysisNone);
// We only add a synonym fact if the bit instruction is not irrelevant, and if
// the new result id we would make it synonymous with is not irrelevant. (It
// could be irrelevant if we are in a dead block.)
if (!transformation_context->GetFactManager()->IdIsIrrelevant(
bit_instruction->result_id()) &&
!transformation_context->GetFactManager()->IdIsIrrelevant(
bit_insert.result_id())) {
// Adds the fact that the last |bit_insert| instruction is synonymous of
// |bit_instruction|.
transformation_context->GetFactManager()->AddFactDataSynonym(
MakeDataDescriptor(bit_insert.result_id(), {}),
MakeDataDescriptor(bit_instruction->result_id(), {}));
}
}
std::unordered_set<uint32_t>
TransformationAddBitInstructionSynonym::GetFreshIds() const {
std::unordered_set<uint32_t> result;
for (auto id : message_.fresh_ids()) {
result.insert(id);
}
return result;
}
} // namespace fuzz
} // namespace spvtools