Merge "Ensure object ArraySet with null value does not need a type check."

3 files changed, 16 insertions, 0 deletions

diff --git a/compiler/optimizing/graph_visualizer.cc b/compiler/optimizing/graph_visualizer.cc
index 4f1e90cd7f..3a9d242df2 100644
--- a/compiler/optimizing/graph_visualizer.cc
+++ b/compiler/optimizing/graph_visualizer.cc
@@ -382,6 +382,8 @@ class HGraphVisualizerPrinter : public HGraphDelegateVisitor {
   void VisitArraySet(HArraySet* array_set) OVERRIDE {
     StartAttributeStream("value_can_be_null") << std::boolalpha
         << array_set->GetValueCanBeNull() << std::noboolalpha;
+    StartAttributeStream("needs_type_check") << std::boolalpha
+        << array_set->NeedsTypeCheck() << std::noboolalpha;
   }
 
   void VisitCompare(HCompare* compare) OVERRIDE {
diff --git a/compiler/optimizing/prepare_for_register_allocation.cc b/compiler/optimizing/prepare_for_register_allocation.cc
index 0ad104eaa7..fc72727196 100644
--- a/compiler/optimizing/prepare_for_register_allocation.cc
+++ b/compiler/optimizing/prepare_for_register_allocation.cc
@@ -47,6 +47,19 @@ void PrepareForRegisterAllocation::VisitBoundType(HBoundType* bound_type) {
   bound_type->GetBlock()->RemoveInstruction(bound_type);
 }
 
+void PrepareForRegisterAllocation::VisitArraySet(HArraySet* instruction) {
+  HInstruction* value = instruction->GetValue();
+  // PrepareForRegisterAllocation::VisitBoundType may have replaced a
+  // BoundType (as value input of this ArraySet) with a NullConstant.
+  // If so, this ArraySet no longer needs a type check.
+  if (value->IsNullConstant()) {
+    DCHECK_EQ(value->GetType(), Primitive::kPrimNot);
+    if (instruction->NeedsTypeCheck()) {
+      instruction->ClearNeedsTypeCheck();
+    }
+  }
+}
+
 void PrepareForRegisterAllocation::VisitClinitCheck(HClinitCheck* check) {
   // Try to find a static invoke or a new-instance from which this check originated.
   HInstruction* implicit_clinit = nullptr;
diff --git a/compiler/optimizing/prepare_for_register_allocation.h b/compiler/optimizing/prepare_for_register_allocation.h
index c90724c251..a6791482a7 100644
--- a/compiler/optimizing/prepare_for_register_allocation.h
+++ b/compiler/optimizing/prepare_for_register_allocation.h
@@ -40,6 +40,7 @@ class PrepareForRegisterAllocation : public HGraphDelegateVisitor {
   void VisitDivZeroCheck(HDivZeroCheck* check) OVERRIDE;
   void VisitBoundsCheck(HBoundsCheck* check) OVERRIDE;
   void VisitBoundType(HBoundType* bound_type) OVERRIDE;
+  void VisitArraySet(HArraySet* instruction) OVERRIDE;
   void VisitClinitCheck(HClinitCheck* check) OVERRIDE;
   void VisitCondition(HCondition* condition) OVERRIDE;
   void VisitInvokeStaticOrDirect(HInvokeStaticOrDirect* invoke) OVERRIDE;