Allocation Info Tracking, continued.

src/arm/code-stubs-arm.cc

 // Copyright 2012 the V8 project authors. All rights reserved.
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 //     * Redistributions of source code must retain the above copyright
 //       notice, this list of conditions and the following disclaimer.
 //     * Redistributions in binary form must reproduce the above
 //       copyright notice, this list of conditions and the following
 //       disclaimer in the documentation and/or other materials provided
@@ skipping 43 matching lines @@
     CodeStubInterfaceDescriptor* descriptor) {
   static Register registers[] = { r0, r1 };
   descriptor->register_param_count_ = 2;
   descriptor->register_params_ = registers;
   Address entry =
       Runtime::FunctionForId(Runtime::kTransitionElementsKind)->entry;
   descriptor->deoptimization_handler_ = FUNCTION_ADDR(entry);
 }
 
 
+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,
                                           Label* slow,
                                           Condition cond);
 static void EmitSmiNonsmiComparison(MacroAssembler* masm,
                                     Register lhs,
                                     Register rhs,
                                     Label* lhs_not_nan,
                                     Label* slow,
@@ skipping 5500 matching lines @@
   __ TailCallRuntime(Runtime::kRegExpConstructResult, 3, 1);
 }
 
 
 static void GenerateRecordCallTarget(MacroAssembler* masm) {
   // Cache the called function in a global property cell.  Cache states
   // are uninitialized, monomorphic (indicated by a JSFunction), and
   // 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());
   ASSERT_EQ(*TypeFeedbackCells::UninitializedSentinel(masm->isolate()),
             masm->isolate()->heap()->the_hole_value());
 
   // Load the cache state into r3.
   __ ldr(r3, FieldMemOperand(r2, JSGlobalPropertyCell::kValueOffset));
 
   // A monomorphic cache hit or an already megamorphic state: invoke the
   // function without changing the state.
   __ cmp(r3, r1);
   __ b(eq, &done);
   __ 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.
-  __ str(r1, FieldMemOperand(r2, JSGlobalPropertyCell::kValueOffset), eq);
+  // 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);
+
+  __ bind(&not_array_function);
+  __ str(r1, FieldMemOperand(r2, JSGlobalPropertyCell::kValueOffset));
   // No need for a write barrier here - cells are rescanned.
 
   __ bind(&done);
 }
 
 
 void CallFunctionStub::Generate(MacroAssembler* masm) {
   // r1 : the function to call
   // r2 : cache cell for call target
   Label slow, non_function;
@@ skipping 97 matching lines @@
   __ JumpIfSmi(r1, &non_function_call);
   // Check that the function is a JSFunction.
   __ CompareObjectType(r1, r3, r3, JS_FUNCTION_TYPE);
   __ b(ne, &slow);
 
   if (RecordCallTarget()) {
     GenerateRecordCallTarget(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
   // r3: object type
   Label do_call;
   __ bind(&slow);
   __ cmp(r3, Operand(JS_FUNCTION_PROXY_TYPE));
   __ b(ne, &non_function_call);
   __ GetBuiltinEntry(r3, Builtins::CALL_FUNCTION_PROXY_AS_CONSTRUCTOR);
   __ jmp(&do_call);
@@ skipping 2205 matching lines @@
 
   __ Pop(lr, r5, r1);
   __ Ret();
 }
 
 #undef __
 
 } }  // namespace v8::internal
 
 #endif  // V8_TARGET_ARCH_ARM