AuroraMiddleware/SPIRV-Tools
1
0
Fork 0
mirror of https://github.com/KhronosGroup/SPIRV-Tools synced 2025-01-14 18:30:19 +00:00
Code Issues Packages Projects Releases Wiki Activity

Compression: removed 'presumed index' feature

Browse Source 
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.
This commit is contained in:
Andrey Tuganov 2017-10-27 11:31:39 -04:00 committed by David Neto
parent f063f91d24
commit 6724c27251
1 changed files with 1 additions and 66 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

67
source/comp/markv_codec.cpp
View File

@ -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)