diff options
author | Andrey Tuganov <andreyt@google.com> | 2017-10-27 11:31:39 -0400 |
---|---|---|
committer | David Neto <dneto@google.com> | 2017-10-28 18:38:13 -0400 |
commit | 6724c272515686398105813de0801407566ae914 (patch) | |
tree | 445ae4c4a0a6df9ca002f90eb72d38202df34a2c /source/comp | |
parent | f063f91d24f83790ba5c3fccd127624260c472f0 (diff) |
Compression: removed 'presumed index' feature
The feature used to improve compression of const integers which were
presumed to be indices. Now obsolete as descriptor-based compression
does this in a more generalized way.
Diffstat (limited to 'source/comp')
-rw-r--r-- | source/comp/markv_codec.cpp | 67 |
1 files changed, 1 insertions, 66 deletions
diff --git a/source/comp/markv_codec.cpp b/source/comp/markv_codec.cpp index 46fb09b5..b5df2b06 100644 --- a/source/comp/markv_codec.cpp +++ b/source/comp/markv_codec.cpp @@ -103,8 +103,6 @@ enum : uint64_t { kMtfTypeIntScalarOrVector, // All types declared as return types in OpTypeFunction. kMtfTypeReturnedByFunction, - // All object ids which are integer constants. - kMtfConstInteger, // All composite objects. kMtfComposite, // All bool objects or vectors of bools. @@ -139,10 +137,6 @@ enum : uint64_t { kMtfIdDescriptorSpaceBegin = 0x100000000, }; -// Used by "presumed index" technique which does special treatment of integer -// constants no greater than this value. -const uint32_t kMarkvMaxPresumedAccessIndex = 31; - // Signals that the value is not in the coding scheme and a fallback method // needs to be used. const uint64_t kMarkvNoneOfTheAbove = MarkvModel::GetMarkvNoneOfTheAbove(); @@ -271,7 +265,7 @@ size_t GetNumBitsToNextByte(size_t bit_pos) { // Defines and returns current MARK-V version. uint32_t GetMarkvVersion() { const uint32_t kVersionMajor = 1; - const uint32_t kVersionMinor = 2; + const uint32_t kVersionMinor = 3; return kVersionMinor | (kVersionMajor << 16); } @@ -556,11 +550,6 @@ class MarkvCodecBase { // List of instructions in the order they are given in the module. std::vector<std::unique_ptr<const Instruction>> instructions_; - // Maps used for the 'presumed id' techniques. Maps small constant integer - // value to its id and back. - std::map<uint32_t, uint32_t> presumed_index_to_id_; - std::map<uint32_t, uint32_t> id_to_presumed_index_; - // Container/computer for id descriptors. IdDescriptorCollection id_descriptors_; @@ -1010,21 +999,6 @@ void MarkvCodecBase::ProcessCurInstruction() { if (multi_mtf_.HasValue(kMtfTypeComposite, inst_.type_id)) multi_mtf_.Insert(kMtfComposite, inst_.result_id); - if (inst_.opcode == SpvOpConstant) { - if (multi_mtf_.HasValue( - GetMtfIdGeneratedByOpcode(SpvOpTypeInt), inst_.type_id)) { - multi_mtf_.Insert(kMtfConstInteger, inst_.result_id); - const uint32_t presumed_index = inst_.words[3]; - if (presumed_index <= kMarkvMaxPresumedAccessIndex) { - const auto result = - presumed_index_to_id_.emplace(presumed_index, inst_.result_id); - if (result.second) { - id_to_presumed_index_.emplace(inst_.result_id, presumed_index); - } - } - } - } - switch (type_inst->opcode()) { case SpvOpTypeInt: case SpvOpTypeBool: @@ -1799,19 +1773,6 @@ spv_result_t MarkvDecoder::DecodeExistingId(uint64_t mtf, uint32_t* id) { } spv_result_t MarkvEncoder::EncodeRefId(uint32_t id) { - // TODO(atgoo@github.com) This might not be needed as EncodeIdWithDescriptor - // can handle SpvOpAccessChain indices if enough statistics is collected. - if (inst_.opcode == SpvOpAccessChain && operand_index_ >= 3) { - const auto it = id_to_presumed_index_.find(id); - if (it != id_to_presumed_index_.end()) { - writer_.WriteBits(1, 1); - writer_.WriteFixedWidth(it->second, kMarkvMaxPresumedAccessIndex); - return SPV_SUCCESS; - } - - writer_.WriteBits(0, 1); - } - { // Try to encode using id descriptor mtfs. const spv_result_t result = EncodeIdWithDescriptor(id); @@ -1849,32 +1810,6 @@ spv_result_t MarkvEncoder::EncodeRefId(uint32_t id) { } spv_result_t MarkvDecoder::DecodeRefId(uint32_t* id) { - if (inst_.opcode == SpvOpAccessChain && operand_index_ >= 3) { - uint64_t use_presumed_index_technique = 0; - if (!reader_.ReadBits(&use_presumed_index_technique, 1)) - return Diag(SPV_ERROR_INVALID_BINARY) - << "Failed to read use_presumed_index_technique flag"; - - if (use_presumed_index_technique) { - uint64_t value = 0; - if (!reader_.ReadFixedWidth(&value, kMarkvMaxPresumedAccessIndex)) - return Diag(SPV_ERROR_INVALID_BINARY) - << "Failed to read presumed_index"; - - const uint32_t presumed_index = static_cast<uint32_t>(value); - - const auto it = presumed_index_to_id_.find(presumed_index); - if (it == presumed_index_to_id_.end()) { - assert(0); - return Diag(SPV_ERROR_INTERNAL) - << "Presumed index id not found"; - } - - *id = it->second; - return SPV_SUCCESS; - } - } - { const spv_result_t result = DecodeIdWithDescriptor(id); if (result != SPV_UNSUPPORTED) |