Optimize IMT
* Remove IMT for classes which do not implement interfaces
* Remove IMT for array classes
* Share same IMT
Saved memory (measured on hammerhead):
boot.art:
Total number of classes: 3854
Number of affected classes: 1637
Saved memory: 409kB
Chrome (excluding classes in boot.art):
Total number of classes: 2409
Number of affected classes: 1259
Saved memory: 314kB
Google Maps (excluding classes in boot.art):
Total number of classes: 6988
Number of affected classes: 2574
Saved memory: 643kB
Performance regression on benchmarks/InvokeInterface.java benchmark
(measured timeCall10Interface)
1st launch: 9.6%
2nd launch: 6.8%
Change-Id: If07e45390014a6ee8f3c1c4ca095b43046f0871f
diff --git a/patchoat/patchoat.cc b/patchoat/patchoat.cc
index 0a7ffda..5bb61bb 100644
--- a/patchoat/patchoat.cc
+++ b/patchoat/patchoat.cc
@@ -494,6 +494,17 @@
image_header->VisitPackedArtMethods(&visitor, heap_->Begin(), pointer_size);
}
+void PatchOat::PatchImTables(const ImageHeader* image_header) {
+ const size_t pointer_size = InstructionSetPointerSize(isa_);
+ // We can safely walk target image since the conflict tables are independent.
+ image_header->VisitPackedImTables(
+ [this](ArtMethod* method) {
+ return RelocatedAddressOfPointer(method);
+ },
+ image_->Begin(),
+ pointer_size);
+}
+
void PatchOat::PatchImtConflictTables(const ImageHeader* image_header) {
const size_t pointer_size = InstructionSetPointerSize(isa_);
// We can safely walk target image since the conflict tables are independent.
@@ -636,6 +647,7 @@
PatchArtFields(image_header);
PatchArtMethods(image_header);
+ PatchImTables(image_header);
PatchImtConflictTables(image_header);
PatchInternedStrings(image_header);
PatchClassTable(image_header);