Use dex cache from compilation unit in RTP.

Avoid calling the costly ClassLinker::FindDexCache() from
reference type propagation when the dex cache from the
compilation unit will do, i.e. almost always. Compiling
the Nexus 5 boot image on host under perf(1) shows that
the FindDexCache() hits drop from about 0.2% to almost
nothing, though enabling inlining for the boot image will
increase it a bit to 0.03% due to unavoidable calls from
the inliner.

Also clean up the ScopedObjectAccess usage a bit.

Change-Id: I426a5f9f5da9e64fad2ea57654240789a48d3871

1 files changed, 5 insertions, 1 deletions

diff --git a/compiler/optimizing/ssa_builder.h b/compiler/optimizing/ssa_builder.h
index c37c28c801..d7360adef8 100644
--- a/compiler/optimizing/ssa_builder.h
+++ b/compiler/optimizing/ssa_builder.h
@@ -47,8 +47,11 @@ namespace art {
  */
 class SsaBuilder : public ValueObject {
  public:
-  SsaBuilder(HGraph* graph, StackHandleScopeCollection* handles)
+  SsaBuilder(HGraph* graph,
+             Handle<mirror::DexCache> dex_cache,
+             StackHandleScopeCollection* handles)
       : graph_(graph),
+        dex_cache_(dex_cache),
         handles_(handles),
         agets_fixed_(false),
         ambiguous_agets_(graph->GetArena()->Adapter(kArenaAllocGraphBuilder)),
@@ -112,6 +115,7 @@ class SsaBuilder : public ValueObject {
   void RemoveRedundantUninitializedStrings();
 
   HGraph* graph_;
+  Handle<mirror::DexCache> dex_cache_;
   StackHandleScopeCollection* const handles_;
 
   // True if types of ambiguous ArrayGets have been resolved.