| // Copyright 2008 Google Inc. |
| // Author: Lincoln Smith |
| // |
| // 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 <config.h> |
| #include "instruction_map.h" |
| #include <string.h> // memset |
| #include "addrcache.h" |
| #include "vcdiff_defs.h" |
| |
| namespace open_vcdiff { |
| |
| // VCDiffInstructionMap members and methods |
| |
| VCDiffInstructionMap* VCDiffInstructionMap::default_instruction_map = NULL; |
| |
| VCDiffInstructionMap* VCDiffInstructionMap::GetDefaultInstructionMap() { |
| if (!default_instruction_map) { |
| default_instruction_map = new VCDiffInstructionMap( |
| VCDiffCodeTableData::kDefaultCodeTableData, |
| VCDiffAddressCache::DefaultLastMode()); |
| } |
| return default_instruction_map; |
| } |
| |
| static unsigned char FindMaxSize( |
| const unsigned char size_array[VCDiffCodeTableData::kCodeTableSize]) { |
| unsigned char max_size = size_array[0]; |
| for (int i = 1; i < VCDiffCodeTableData::kCodeTableSize; ++i) { |
| if (size_array[i] > max_size) { |
| max_size = size_array[i]; |
| } |
| } |
| return max_size; |
| } |
| |
| static void ClearSizeOpcodeArray(int length, OpcodeOrNone* array) { |
| for (int i = 0; i < length; ++i) { |
| array[i] = kNoOpcode; |
| } |
| } |
| |
| static OpcodeOrNone* NewSizeOpcodeArray(int length) { |
| OpcodeOrNone* array = new OpcodeOrNone[length]; |
| ClearSizeOpcodeArray(length, array); |
| return array; |
| } |
| |
| VCDiffInstructionMap::FirstInstructionMap::FirstInstructionMap( |
| int num_insts_and_modes, |
| int max_size_1) |
| : num_instruction_type_modes_(num_insts_and_modes), |
| max_size_1_(max_size_1) { |
| first_opcodes_ = new OpcodeOrNone*[num_instruction_type_modes_]; |
| for (int i = 0; i < num_instruction_type_modes_; ++i) { |
| // There must be at least (max_size_1_ + 1) elements in first_opcodes_ |
| // because the element first_opcodes[max_size_1_] will be referenced. |
| first_opcodes_[i] = NewSizeOpcodeArray(max_size_1_ + 1); |
| } |
| } |
| |
| VCDiffInstructionMap::FirstInstructionMap::~FirstInstructionMap() { |
| for (int i = 0; i < num_instruction_type_modes_; ++i) { |
| delete[] first_opcodes_[i]; |
| } |
| delete[] first_opcodes_; |
| } |
| |
| VCDiffInstructionMap::SecondInstructionMap::SecondInstructionMap( |
| int num_insts_and_modes, |
| int max_size_2) |
| : num_instruction_type_modes_(num_insts_and_modes), |
| max_size_2_(max_size_2) { |
| memset(second_opcodes_, 0, sizeof(second_opcodes_)); |
| } |
| |
| |
| VCDiffInstructionMap::SecondInstructionMap::~SecondInstructionMap() { |
| for (int opcode = 0; opcode < VCDiffCodeTableData::kCodeTableSize; ++opcode) { |
| if (second_opcodes_[opcode] != NULL) { |
| for (int inst_mode = 0; |
| inst_mode < num_instruction_type_modes_; |
| ++inst_mode) { |
| // No need to check for NULL |
| delete[] second_opcodes_[opcode][inst_mode]; |
| } |
| delete[] second_opcodes_[opcode]; |
| } |
| } |
| } |
| |
| void VCDiffInstructionMap::SecondInstructionMap::Add( |
| unsigned char first_opcode, |
| unsigned char inst, |
| unsigned char size, |
| unsigned char mode, |
| unsigned char second_opcode) { |
| OpcodeOrNone**& inst_mode_array = second_opcodes_[first_opcode]; |
| if (!inst_mode_array) { |
| inst_mode_array = new OpcodeOrNone*[num_instruction_type_modes_]; |
| memset(inst_mode_array, |
| 0, |
| num_instruction_type_modes_ * sizeof(inst_mode_array[0])); |
| } |
| OpcodeOrNone*& size_array = inst_mode_array[inst + mode]; |
| if (!size_array) { |
| // There must be at least (max_size_2_ + 1) elements in size_array |
| // because the element size_array[max_size_2_] will be referenced. |
| size_array = NewSizeOpcodeArray(max_size_2_ + 1); |
| } |
| if (size_array[size] == kNoOpcode) { |
| size_array[size] = second_opcode; |
| } |
| } |
| |
| OpcodeOrNone VCDiffInstructionMap::SecondInstructionMap::Lookup( |
| unsigned char first_opcode, |
| unsigned char inst, |
| unsigned char size, |
| unsigned char mode) const { |
| if (size > max_size_2_) { |
| return kNoOpcode; |
| } |
| const OpcodeOrNone* const * const inst_mode_array = |
| second_opcodes_[first_opcode]; |
| if (!inst_mode_array) { |
| return kNoOpcode; |
| } |
| int inst_mode = (inst == VCD_COPY) ? (inst + mode) : inst; |
| const OpcodeOrNone* const size_array = inst_mode_array[inst_mode]; |
| if (!size_array) { |
| return kNoOpcode; |
| } |
| return size_array[size]; |
| } |
| |
| // Because a constructor should never fail, the caller must already |
| // have run ValidateCodeTable() against the code table data. |
| // |
| VCDiffInstructionMap::VCDiffInstructionMap( |
| const VCDiffCodeTableData& code_table_data, |
| unsigned char max_mode) |
| : first_instruction_map_(VCD_LAST_INSTRUCTION_TYPE + max_mode + 1, |
| FindMaxSize(code_table_data.size1)), |
| second_instruction_map_(VCD_LAST_INSTRUCTION_TYPE + max_mode + 1, |
| FindMaxSize(code_table_data.size2)) { |
| // First pass to fill up first_instruction_map_ |
| for (int opcode = 0; opcode < VCDiffCodeTableData::kCodeTableSize; ++opcode) { |
| if (code_table_data.inst2[opcode] == VCD_NOOP) { |
| // Single instruction. If there is more than one opcode for the same |
| // inst, mode, and size, then the lowest-numbered opcode will always |
| // be used by the encoder, because of the descending loop. |
| first_instruction_map_.Add(code_table_data.inst1[opcode], |
| code_table_data.size1[opcode], |
| code_table_data.mode1[opcode], |
| opcode); |
| } else if (code_table_data.inst1[opcode] == VCD_NOOP) { |
| // An unusual case where inst1 == NOOP and inst2 == ADD, RUN, or COPY. |
| // This is valid under the standard, but unlikely to be used. |
| // Add it to the first instruction map as if inst1 and inst2 were swapped. |
| first_instruction_map_.Add(code_table_data.inst2[opcode], |
| code_table_data.size2[opcode], |
| code_table_data.mode2[opcode], |
| opcode); |
| } |
| } |
| // Second pass to fill up second_instruction_map_ (depends on first pass) |
| for (int opcode = 0; opcode < VCDiffCodeTableData::kCodeTableSize; ++opcode) { |
| if ((code_table_data.inst1[opcode] != VCD_NOOP) && |
| (code_table_data.inst2[opcode] != VCD_NOOP)) { |
| // Double instruction. Find the corresponding single instruction opcode |
| const OpcodeOrNone single_opcode = |
| LookupFirstOpcode(code_table_data.inst1[opcode], |
| code_table_data.size1[opcode], |
| code_table_data.mode1[opcode]); |
| if (single_opcode == kNoOpcode) continue; // No single opcode found |
| second_instruction_map_.Add(static_cast<unsigned char>(single_opcode), |
| code_table_data.inst2[opcode], |
| code_table_data.size2[opcode], |
| code_table_data.mode2[opcode], |
| opcode); |
| } |
| } |
| } |
| |
| }; // namespace open_vcdiff |
