| // 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( |
| protobufs::TransformationAdjustBranchWeights message) |
| : message_(std::move(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; |
| } |
| |
| std::unordered_set<uint32_t> TransformationAdjustBranchWeights::GetFreshIds() |
| const { |
| return std::unordered_set<uint32_t>(); |
| } |
| |
| } // namespace fuzz |
| } // namespace spvtools |