Profile compression: Replace method index with difference with the last method_index
Store the difference with the last method index in the profile rather than
putting the actual method index. Leveraging the common difference values,
compressing the profile will reduce the size further.
Results:
App1
Without - 74K
With - 58K
App2
Without - 54K
With - 30K
App3
Without 40K,
With - 24K
Bug: 36281963
Test: dexlayout_test, profile_assistant_test, \
profman_test, profile_compilation_info_test
Change-Id: I96bcadac250c08aaf23ade7465c5ac6ba9ea75dc
diff --git a/dexlayout/dexlayout_test.cc b/dexlayout/dexlayout_test.cc
index d2aef27..5a6a20d 100644
--- a/dexlayout/dexlayout_test.cc
+++ b/dexlayout/dexlayout_test.cc
@@ -41,7 +41,7 @@
"AAAAdQEAAAAQAAABAAAAjAEAAA==";
static const char kDexFileLayoutInputProfile[] =
- "cHJvADAwNgAAAAAAAAgAAAB4AQMAAAAAAQ==";
+ "cHJvADAwNwAAAAAAAAgAAAB4AQMAAAAAAQ==";
// Dex file with catch handler unreferenced by try blocks.
// Constructed by building a dex file with try/catch blocks and hex editing.
diff --git a/runtime/jit/profile_compilation_info.cc b/runtime/jit/profile_compilation_info.cc
index f163a59..d922bc4 100644
--- a/runtime/jit/profile_compilation_info.cc
+++ b/runtime/jit/profile_compilation_info.cc
@@ -45,8 +45,9 @@
namespace art {
const uint8_t ProfileCompilationInfo::kProfileMagic[] = { 'p', 'r', 'o', '\0' };
-// Last profile version: Compress profile data.
-const uint8_t ProfileCompilationInfo::kProfileVersion[] = { '0', '0', '6', '\0' };
+// Last profile version: Instead of method index, put the difference with the last
+// method's index.
+const uint8_t ProfileCompilationInfo::kProfileVersion[] = { '0', '0', '7', '\0' };
static constexpr uint16_t kMaxDexFileKeyLength = PATH_MAX;
@@ -302,12 +303,25 @@
AddStringToBuffer(&buffer, dex_data.profile_key);
+ uint16_t last_method_index = 0;
for (const auto& method_it : dex_data.method_map) {
- AddUintToBuffer(&buffer, method_it.first);
+ // Store the difference between the method indices. The SafeMap is ordered by
+ // method_id, so the difference will always be non negative.
+ DCHECK_GE(method_it.first, last_method_index);
+ uint16_t diff_with_last_method_index = method_it.first - last_method_index;
+ last_method_index = method_it.first;
+ AddUintToBuffer(&buffer, diff_with_last_method_index);
AddInlineCacheToBuffer(&buffer, method_it.second);
}
+
+ uint16_t last_class_index = 0;
for (const auto& class_id : dex_data.class_set) {
- AddUintToBuffer(&buffer, class_id.index_);
+ // Store the difference between the class indices. The set is ordered by
+ // class_id, so the difference will always be non negative.
+ DCHECK_GE(class_id.index_, last_class_index);
+ uint16_t diff_with_last_class_index = class_id.index_ - last_class_index;
+ last_class_index = class_id.index_;
+ AddUintToBuffer(&buffer, diff_with_last_class_index);
}
}
@@ -632,11 +646,13 @@
}
size_t expected_unread_bytes_after_operation = buffer.CountUnreadBytes()
- line_header.method_region_size_bytes;
+ uint16_t last_method_index = 0;
while (buffer.CountUnreadBytes() > expected_unread_bytes_after_operation) {
DexFileData* const data = GetOrAddDexFileData(line_header.dex_location, line_header.checksum);
- uint16_t method_index;
- READ_UINT(uint16_t, buffer, method_index, error);
-
+ uint16_t diff_with_last_method_index;
+ READ_UINT(uint16_t, buffer, diff_with_last_method_index, error);
+ uint16_t method_index = last_method_index + diff_with_last_method_index;
+ last_method_index = method_index;
auto it = data->method_map.FindOrAdd(method_index);
if (!ReadInlineCache(buffer, number_of_dex_files, &(it->second), error)) {
return false;
@@ -659,9 +675,12 @@
return kProfileLoadBadData;
}
+ uint16_t last_class_index = 0;
for (uint16_t i = 0; i < line_header.class_set_size; i++) {
- uint16_t type_index;
- READ_UINT(uint16_t, buffer, type_index, error);
+ uint16_t diff_with_last_class_index;
+ READ_UINT(uint16_t, buffer, diff_with_last_class_index, error);
+ uint16_t type_index = last_class_index + diff_with_last_class_index;
+ last_class_index = type_index;
if (!AddClassIndex(line_header.dex_location,
line_header.checksum,
dex::TypeIndex(type_index))) {