dexanalyze: Improve field analysis.
Analyze also SGET/SPUT and better estimate the savings based
on given field index and in/out cutoff.
Experiments with core-oj indicate that the cutoffs 16/16 are
good for IGET/IPUT but SGET/SPUT would benefit more from
32/8 (assuming we want to use 8 bits together for the field
index and in/out).
Test: Manually run dexanalyze.
Change-Id: Id7cddaf20be4b345516777be6fbc599aed79ac5b
diff --git a/tools/dexanalyze/dexanalyze_experiments.cc b/tools/dexanalyze/dexanalyze_experiments.cc
index d4e3f1f..e216f89 100644
--- a/tools/dexanalyze/dexanalyze_experiments.cc
+++ b/tools/dexanalyze/dexanalyze_experiments.cc
@@ -321,15 +321,73 @@
// Types accessed and count.
std::map<size_t, size_t> types_accessed;
- // Map from dex field index -> class field index.
- std::map<uint32_t, uint32_t> field_index_map_;
+ // Maps from dex field index -> class field index (static or instance).
+ std::map<uint32_t, uint32_t> static_field_index_map_;
size_t current_idx = 0u;
- for (const ClassAccessor::Field& field : accessor.GetInstanceFields()) {
- field_index_map_[field.GetIndex()] = current_idx++;
+ for (const ClassAccessor::Field& field : accessor.GetStaticFields()) {
+ static_field_index_map_[field.GetIndex()] = current_idx++;
}
+ std::map<uint32_t, uint32_t> instance_field_index_map_;
+ current_idx = 0u;
+ for (const ClassAccessor::Field& field : accessor.GetInstanceFields()) {
+ instance_field_index_map_[field.GetIndex()] = current_idx++;
+ }
+ auto ProcessInstanceField = [&](const Instruction& inst,
+ uint32_t first_arg_reg,
+ const std::map<uint32_t, uint32_t>& index_map,
+ /*inout*/ InstanceFieldAccessStats* stats) {
+ const uint32_t dex_field_idx = inst.VRegC_22c();
+ ++types_accessed[dex_file.GetFieldId(dex_field_idx).class_idx_.index_];
+ uint32_t input = inst.VRegA_22c();
+ ++stats->inout_[input];
+ const uint32_t receiver = inst.VRegB_22c();
+ // FIXME: This is weird if receiver < first_arg_reg.
+ ++stats->receiver_[(receiver - first_arg_reg) & 0xF];
+ if (first_arg_reg == receiver) {
+ auto it = index_map.find(dex_field_idx);
+ if (it != index_map.end() && it->second < FieldAccessStats::kMaxFieldIndex) {
+ ++stats->field_index_[it->second];
+ } else {
+ ++stats->field_index_other_;
+ }
+ if (it != index_map.end() &&
+ it->second < FieldAccessStats::kShortBytecodeFieldIndexOutCutOff &&
+ input < FieldAccessStats::kShortBytecodeInOutCutOff) {
+ ++stats->short_bytecode_;
+ }
+ }
+ };
+ auto ProcessStaticField = [&](const Instruction& inst,
+ const std::map<uint32_t, uint32_t>& index_map,
+ /*inout*/ StaticFieldAccessStats* stats) {
+ const uint32_t dex_field_idx = inst.VRegB_21c();
+ ++types_accessed[dex_file.GetFieldId(dex_field_idx).class_idx_.index_];
+ uint8_t output = inst.VRegA_21c();
+ if (output < 16u) {
+ ++stats->inout_[output];
+ } else {
+ ++stats->inout_other_;
+ }
+ auto it = index_map.find(dex_field_idx);
+ if (it != index_map.end() && it->second < FieldAccessStats::kMaxFieldIndex) {
+ ++stats->field_index_[it->second];
+ } else {
+ ++stats->field_index_other_;
+ }
+ if (it != index_map.end() &&
+ it->second < FieldAccessStats::kShortBytecodeFieldIndexOutCutOff &&
+ output < FieldAccessStats::kShortBytecodeInOutCutOff) {
+ ++stats->short_bytecode_;
+ }
+ };
for (const ClassAccessor::Method& method : accessor.GetMethods()) {
CodeItemDataAccessor code_item(dex_file, method.GetCodeItem());
+ const uint32_t first_arg_reg =
+ ((method.GetAccessFlags() & kAccStatic) == 0)
+ ? code_item.RegistersSize() - code_item.InsSize()
+ : static_cast<uint32_t>(-1);
+
dex_code_bytes_ += code_item.InsnsSizeInBytes();
unique_code_items.insert(method.GetCodeItemOffset());
for (const DexInstructionPcPair& inst : code_item) {
@@ -346,7 +404,11 @@
case Instruction::IGET_BOOLEAN:
case Instruction::IGET_BYTE:
case Instruction::IGET_CHAR:
- case Instruction::IGET_SHORT:
+ case Instruction::IGET_SHORT: {
+ ProcessInstanceField(
+ inst.Inst(), first_arg_reg, instance_field_index_map_, &iget_stats_);
+ break;
+ }
case Instruction::IPUT:
case Instruction::IPUT_WIDE:
case Instruction::IPUT_OBJECT:
@@ -354,20 +416,28 @@
case Instruction::IPUT_BYTE:
case Instruction::IPUT_CHAR:
case Instruction::IPUT_SHORT: {
- const uint32_t receiver = inst->VRegB_22c();
- const uint32_t dex_field_idx = inst->VRegC_22c();
- const uint32_t first_arg_reg = code_item.RegistersSize() - code_item.InsSize();
- ++field_receiver_[(receiver - first_arg_reg) & 0xF];
- ++types_accessed[dex_file.GetFieldId(dex_field_idx).class_idx_.index_];
- if (first_arg_reg == receiver) {
- auto it = field_index_map_.find(dex_field_idx);
- if (it != field_index_map_.end() && it->second < kMaxFieldIndex) {
- ++field_index_[it->second];
- } else {
- ++field_index_other_;
- }
- }
- ++field_output_[inst->VRegA_22c()];
+ ProcessInstanceField(
+ inst.Inst(), first_arg_reg, instance_field_index_map_, &iput_stats_);
+ break;
+ }
+ case Instruction::SGET:
+ case Instruction::SGET_WIDE:
+ case Instruction::SGET_OBJECT:
+ case Instruction::SGET_BOOLEAN:
+ case Instruction::SGET_BYTE:
+ case Instruction::SGET_CHAR:
+ case Instruction::SGET_SHORT: {
+ ProcessStaticField(inst.Inst(), static_field_index_map_, &sget_stats_);
+ break;
+ }
+ case Instruction::SPUT:
+ case Instruction::SPUT_WIDE:
+ case Instruction::SPUT_OBJECT:
+ case Instruction::SPUT_BOOLEAN:
+ case Instruction::SPUT_BYTE:
+ case Instruction::SPUT_CHAR:
+ case Instruction::SPUT_SHORT: {
+ ProcessStaticField(inst.Inst(), static_field_index_map_, &sput_stats_);
break;
}
case Instruction::CONST_STRING_JUMBO: {
@@ -479,22 +549,55 @@
}
void CountDexIndices::Dump(std::ostream& os, uint64_t total_size) const {
- const uint64_t fields_total = std::accumulate(field_receiver_, field_receiver_ + 16u, 0u);
- for (size_t i = 0; i < 16; ++i) {
- os << "receiver_reg=" << i << ": " << Percent(field_receiver_[i], fields_total) << "\n";
- }
- for (size_t i = 0; i < 16; ++i) {
- os << "output_reg=" << i << ": " << Percent(field_output_[i], fields_total) << "\n";
- }
- const uint64_t fields_idx_total = std::accumulate(field_index_,
- field_index_ + kMaxFieldIndex,
- 0u) + field_index_other_;
- for (size_t i = 0; i < kMaxFieldIndex; ++i) {
- os << "field_idx=" << i << ": " << Percent(field_index_[i], fields_idx_total) << "\n";
- }
- os << "field_idx=other: " << Percent(field_index_other_, fields_idx_total) << "\n";
- os << "field_idx_savings=" << Percent((fields_idx_total - field_index_other_) * 2, total_size)
- << "\n";
+ auto DumpInstanceFieldStats = [&](const char* tag, const InstanceFieldAccessStats& stats) {
+ const uint64_t fields_total = std::accumulate(stats.inout_, stats.inout_ + 16u, 0u);
+ os << tag << "\n";
+ for (size_t i = 0; i < 16; ++i) {
+ os << " receiver_reg=" << i << ": " << Percent(stats.receiver_[i], fields_total) << "\n";
+ }
+ DCHECK(tag[1] == 'G' || tag[1] == 'P');
+ const char* inout_tag = (tag[1] == 'G') ? "output_reg" : "input_reg";
+ for (size_t i = 0; i < 16; ++i) {
+ os << " " << inout_tag << "=" << i << ": " << Percent(stats.inout_[i], fields_total) << "\n";
+ }
+ const uint64_t fields_idx_total = std::accumulate(
+ stats.field_index_,
+ stats.field_index_ + FieldAccessStats::kMaxFieldIndex,
+ stats.field_index_other_);
+ for (size_t i = 0; i < FieldAccessStats::kMaxFieldIndex; ++i) {
+ os << " field_idx=" << i << ": " << Percent(stats.field_index_[i], fields_idx_total) << "\n";
+ }
+ os << " field_idx=other: " << Percent(stats.field_index_other_, fields_idx_total) << "\n";
+ os << " short_bytecode: " << Percent(stats.short_bytecode_, fields_total) << "\n";
+ os << " short_bytecode_savings=" << Percent(stats.short_bytecode_ * 2, total_size) << "\n";
+ };
+ DumpInstanceFieldStats("IGET", iget_stats_);
+ DumpInstanceFieldStats("IPUT", iput_stats_);
+
+ auto DumpStaticFieldStats = [&](const char* tag, const StaticFieldAccessStats& stats) {
+ const uint64_t fields_total =
+ std::accumulate(stats.inout_, stats.inout_ + 16u, stats.inout_other_);
+ os << tag << "\n";
+ DCHECK(tag[1] == 'G' || tag[1] == 'P');
+ const char* inout_tag = (tag[1] == 'G') ? "output_reg" : "input_reg";
+ for (size_t i = 0; i < 16; ++i) {
+ os << " " << inout_tag << "=" << i << ": " << Percent(stats.inout_[i], fields_total) << "\n";
+ }
+ os << " " << inout_tag << "=other: " << Percent(stats.inout_other_, fields_total) << "\n";
+ const uint64_t fields_idx_total = std::accumulate(
+ stats.field_index_,
+ stats.field_index_ + FieldAccessStats::kMaxFieldIndex,
+ stats.field_index_other_);
+ for (size_t i = 0; i < FieldAccessStats::kMaxFieldIndex; ++i) {
+ os << " field_idx=" << i << ": " << Percent(stats.field_index_[i], fields_idx_total) << "\n";
+ }
+ os << " field_idx=other: " << Percent(stats.field_index_other_, fields_idx_total) << "\n";
+ os << " short_bytecode: " << Percent(stats.short_bytecode_, fields_total) << "\n";
+ os << " short_bytecode_savings=" << Percent(stats.short_bytecode_ * 2, total_size) << "\n";
+ };
+ DumpStaticFieldStats("SGET", sget_stats_);
+ DumpStaticFieldStats("SPUT", sput_stats_);
+
os << "Num string ids: " << num_string_ids_ << "\n";
os << "Num method ids: " << num_method_ids_ << "\n";
os << "Num field ids: " << num_field_ids_ << "\n";
diff --git a/tools/dexanalyze/dexanalyze_experiments.h b/tools/dexanalyze/dexanalyze_experiments.h
index 0cafe27..c59cd0b 100644
--- a/tools/dexanalyze/dexanalyze_experiments.h
+++ b/tools/dexanalyze/dexanalyze_experiments.h
@@ -98,11 +98,25 @@
size_t total_unique_string_ids_ = 0;
uint64_t total_unique_code_items_ = 0u;
- static constexpr size_t kMaxFieldIndex = 32;
- uint64_t field_index_[kMaxFieldIndex] = {};
- uint64_t field_index_other_ = 0u;
- uint64_t field_receiver_[16] = {};
- uint64_t field_output_[16] = {};
+ struct FieldAccessStats {
+ static constexpr size_t kMaxFieldIndex = 32;
+ uint64_t field_index_[kMaxFieldIndex] = {};
+ uint64_t field_index_other_ = 0u;
+ uint64_t inout_[16] = {}; // Input for IPUT/SPUT, output for IGET/SGET.
+ static constexpr size_t kShortBytecodeFieldIndexOutCutOff = 16u;
+ static constexpr size_t kShortBytecodeInOutCutOff = 16u;
+ uint64_t short_bytecode_ = 0u;
+ };
+ struct InstanceFieldAccessStats : FieldAccessStats {
+ uint64_t receiver_[16] = {};
+ };
+ struct StaticFieldAccessStats : FieldAccessStats {
+ uint64_t inout_other_ = 0u; // Input for SPUT, output for SGET.
+ };
+ InstanceFieldAccessStats iget_stats_;
+ InstanceFieldAccessStats iput_stats_;
+ StaticFieldAccessStats sget_stats_;
+ StaticFieldAccessStats sput_stats_;
// Unique names.
uint64_t total_unique_method_names_ = 0u;
