SPIRV-Tools/source/fuzz/transformation_adjust_branch_weights.cpp

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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_adjust_branch_weights.h"
#include "source/fuzz/fuzzer_util.h"
#include "source/fuzz/instruction_descriptor.h"
namespace spvtools {
namespace fuzz {
namespace {
const uint32_t kBranchWeightForTrueLabelIndex = 3;
const uint32_t kBranchWeightForFalseLabelIndex = 4;
} // namespace
TransformationAdjustBranchWeights::TransformationAdjustBranchWeights(
const spvtools::fuzz::protobufs::TransformationAdjustBranchWeights& message)
: message_(message) {}
TransformationAdjustBranchWeights::TransformationAdjustBranchWeights(
const protobufs::InstructionDescriptor& instruction_descriptor,
const std::pair<uint32_t, uint32_t>& branch_weights) {
*message_.mutable_instruction_descriptor() = instruction_descriptor;
message_.mutable_branch_weights()->set_first(branch_weights.first);
message_.mutable_branch_weights()->set_second(branch_weights.second);
}
bool TransformationAdjustBranchWeights::IsApplicable(
opt::IRContext* ir_context, const TransformationContext& /*unused*/) const {
auto instruction =
FindInstruction(message_.instruction_descriptor(), ir_context);
if (instruction == nullptr) {
return false;
}
SpvOp opcode = static_cast<SpvOp>(
message_.instruction_descriptor().target_instruction_opcode());
assert(instruction->opcode() == opcode &&
"The located instruction must have the same opcode as in the "
"descriptor.");
// Must be an OpBranchConditional instruction.
if (opcode != SpvOpBranchConditional) {
return false;
}
assert((message_.branch_weights().first() != 0 ||
message_.branch_weights().second() != 0) &&
"At least one weight must be non-zero.");
assert(message_.branch_weights().first() <=
UINT32_MAX - message_.branch_weights().second() &&
"The sum of the two weights must not be greater than UINT32_MAX.");
return true;
}
void TransformationAdjustBranchWeights::Apply(
opt::IRContext* ir_context, TransformationContext* /*unused*/) const {
auto instruction =
FindInstruction(message_.instruction_descriptor(), ir_context);
if (instruction->HasBranchWeights()) {
instruction->SetOperand(kBranchWeightForTrueLabelIndex,
{message_.branch_weights().first()});
instruction->SetOperand(kBranchWeightForFalseLabelIndex,
{message_.branch_weights().second()});
} else {
instruction->AddOperand({SPV_OPERAND_TYPE_OPTIONAL_LITERAL_INTEGER,
{message_.branch_weights().first()}});
instruction->AddOperand({SPV_OPERAND_TYPE_OPTIONAL_LITERAL_INTEGER,
{message_.branch_weights().second()}});
}
}
protobufs::Transformation TransformationAdjustBranchWeights::ToMessage() const {
protobufs::Transformation result;
*result.mutable_adjust_branch_weights() = message_;
return result;
}
} // namespace fuzz
} // namespace spvtools