commit badee9820fcf5dca5f8c46c3215ae1779ee7736e
author Nelli Kim <nelli.kim@samsung.com> Fri May 13 13:08:53 2016 +0300
committer Matthew Gharrity <gharrma@google.com> Tue Jun 14 10:05:47 2016 -0700
tree 982948a67a88a1f9a734c935f919f8d307969f48
parent 614968198625a6693666bdc1e5609e2f663f5638

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

runtime/entrypoints/entrypoint_utils-inl.h

diff --git a/runtime/entrypoints/entrypoint_utils-inl.h b/runtime/entrypoints/entrypoint_utils-inl.h
index fc62573..916ca29 100644
--- a/runtime/entrypoints/entrypoint_utils-inl.h
+++ b/runtime/entrypoints/entrypoint_utils-inl.h
@@ -559,9 +559,10 @@
       }
     }
     case kInterface: {
-      uint32_t imt_index = resolved_method->GetDexMethodIndex() % mirror::Class::kImtSize;
-      ArtMethod* imt_method = (*this_object)->GetClass()->GetEmbeddedImTableEntry(
-          imt_index, class_linker->GetImagePointerSize());
+      uint32_t imt_index = resolved_method->GetDexMethodIndex() % ImTable::kSize;
+      size_t pointer_size = class_linker->GetImagePointerSize();
+      ArtMethod* imt_method = (*this_object)->GetClass()->GetImt(pointer_size)->
+          Get(imt_index, pointer_size);
       if (!imt_method->IsRuntimeMethod()) {
         if (kIsDebugBuild) {
           mirror::Class* klass = (*this_object)->GetClass();