Allocation Info Tracking, continued.

src/arm/code-stubs-arm.cc

Index: src/arm/code-stubs-arm.cc
diff --git a/src/arm/code-stubs-arm.cc b/src/arm/code-stubs-arm.cc
index 62fcc9a981ccd5946ed7946d006d7e6d5224d4d1..a3701037b9cb29749a5ddd320d94905c4319051d 100644
--- a/src/arm/code-stubs-arm.cc
+++ b/src/arm/code-stubs-arm.cc
@@ -61,6 +61,40 @@ void TransitionElementsKindStub::InitializeInterfaceDescriptor(
 }
 
 
+static void InitializeArrayConstructorDescriptor(Isolate* isolate,
+    CodeStubInterfaceDescriptor* descriptor) {
+  static Register registers[] = { r1, r2 };
+  descriptor->register_param_count_ = 2;
+  // stack param count needs (constructor pointer, and single argument)
+  descriptor->stack_parameter_count_ = &r0;
+  descriptor->register_params_ = registers;
+  descriptor->extra_expression_stack_count_ = 1;
+  descriptor->deoptimization_handler_ =
+      FUNCTION_ADDR(ArrayConstructor_StubFailure);
+}
+
+
+void ArrayNoArgumentConstructorStub::InitializeInterfaceDescriptor(
+    Isolate* isolate,
+    CodeStubInterfaceDescriptor* descriptor) {
+  InitializeArrayConstructorDescriptor(isolate, descriptor);
+}
+
+
+void ArraySingleArgumentConstructorStub::InitializeInterfaceDescriptor(
+    Isolate* isolate,
+    CodeStubInterfaceDescriptor* descriptor) {
+  InitializeArrayConstructorDescriptor(isolate, descriptor);
+}
+
+
+void ArrayNArgumentsConstructorStub::InitializeInterfaceDescriptor(
+    Isolate* isolate,
+    CodeStubInterfaceDescriptor* descriptor) {
+  InitializeArrayConstructorDescriptor(isolate, descriptor);
+}
+
+
 #define __ ACCESS_MASM(masm)
 
 static void EmitIdenticalObjectComparison(MacroAssembler* masm,
@@ -5581,7 +5615,7 @@ static void GenerateRecordCallTarget(MacroAssembler* masm) {
   // megamorphic.
   // r1 : the function to call
   // r2 : cache cell for call target
-  Label done;
+  Label initialize, done, miss, megamorphic, not_array_function;
 
   ASSERT_EQ(*TypeFeedbackCells::MegamorphicSentinel(masm->isolate()),
             masm->isolate()->heap()->undefined_value());
@@ -5598,16 +5632,62 @@ static void GenerateRecordCallTarget(MacroAssembler* masm) {
   __ CompareRoot(r3, Heap::kUndefinedValueRootIndex);
   __ b(eq, &done);
 
+  // Special handling of the Array() function, which caches not only the
+  // monomorphic Array function but the initial ElementsKind with special
+  // sentinels
+  Handle<Object> terminal_kind_sentinel =
+      TypeFeedbackCells::MonomorphicArraySentinel(LAST_FAST_ELEMENTS_KIND);
+  __ cmp(r3, Operand(terminal_kind_sentinel));
+  __ b(ne, &miss);
+  // Load the global or builtins object from the current context
+  __ ldr(r3, MemOperand(cp, Context::SlotOffset(Context::GLOBAL_OBJECT_INDEX)));
+  __ ldr(r3, FieldMemOperand(r3, GlobalObject::kGlobalContextOffset));
+  // Make sure the function is the Array() function
+  __ ldr(r3,
+         MemOperand(r3, Context::SlotOffset(Context::ARRAY_FUNCTION_INDEX)));
+  __ cmp(r1, r3);
+  Label megamorphic_pre;
+  __ b(ne, &megamorphic_pre);
+  __ jmp(&done);
+
+  __ bind(&megamorphic_pre);
+  __ jmp(&megamorphic);
+
+  __ bind(&miss);
+
   // A monomorphic miss (i.e, here the cache is not uninitialized) goes
   // megamorphic.
   __ CompareRoot(r3, Heap::kTheHoleValueRootIndex);
+  __ b(eq, &initialize);
   // MegamorphicSentinel is an immortal immovable object (undefined) so no
   // write-barrier is needed.
-  __ LoadRoot(ip, Heap::kUndefinedValueRootIndex, ne);
-  __ str(ip, FieldMemOperand(r2, JSGlobalPropertyCell::kValueOffset), ne);
+  __ bind(&megamorphic);
+  __ LoadRoot(ip, Heap::kUndefinedValueRootIndex);
+  __ str(ip, FieldMemOperand(r2, JSGlobalPropertyCell::kValueOffset));
+
+  // An uninitialized cache is patched with the function or sentinel to
+  // indicate the ElementsKind if function is the Array constructor.
+  __ bind(&initialize);
+  __ ldr(r3, MemOperand(cp, Context::SlotOffset(Context::GLOBAL_OBJECT_INDEX)));
+  __ ldr(r3, FieldMemOperand(r3, GlobalObject::kGlobalContextOffset));
+  __ ldr(r3,
+         MemOperand(r3, Context::SlotOffset(Context::ARRAY_FUNCTION_INDEX)));
+  // Make sure the function is the Array() function
+  __ cmp(r1, r3);
+  __ b(ne, &not_array_function);
+
+  // The target function is the Array constructor, install a sentinel value in
+  // the constructor's type info cell that will track the initial ElementsKind
+  // that should be used for the array when its constructed.
+  Handle<Object> initial_kind_sentinel =
+      TypeFeedbackCells::MonomorphicArraySentinel(
+          GetInitialFastElementsKind());
+  __ mov(r3, Operand(initial_kind_sentinel));
+  __ str(r3, FieldMemOperand(r2, JSGlobalPropertyCell::kValueOffset));
+  __ b(&done);
 
-  // An uninitialized cache is patched with the function.
-  __ str(r1, FieldMemOperand(r2, JSGlobalPropertyCell::kValueOffset), eq);
+  __ bind(&not_array_function);
+  __ str(r1, FieldMemOperand(r2, JSGlobalPropertyCell::kValueOffset));
   // No need for a write barrier here - cells are rescanned.
 
   __ bind(&done);
@@ -5725,9 +5805,9 @@ void CallConstructStub::Generate(MacroAssembler* masm) {
   }
 
   // Jump to the function-specific construct stub.
-  __ ldr(r2, FieldMemOperand(r1, JSFunction::kSharedFunctionInfoOffset));
-  __ ldr(r2, FieldMemOperand(r2, SharedFunctionInfo::kConstructStubOffset));
-  __ add(pc, r2, Operand(Code::kHeaderSize - kHeapObjectTag));
+  __ ldr(r3, FieldMemOperand(r1, JSFunction::kSharedFunctionInfoOffset));
+  __ ldr(r3, FieldMemOperand(r3, SharedFunctionInfo::kConstructStubOffset));
+  __ add(pc, r3, Operand(Code::kHeaderSize - kHeapObjectTag));
 
   // r0: number of arguments
   // r1: called object