void CodeGenerator::GenerateClassOf(ZoneList<Expression*>* args) {
VirtualFrame::SpilledScope spilled_scope;
ASSERT(args->length() == 1);
- LoadAndSpill(args->at(0)); // Load the object.
- frame_->CallRuntime(Runtime::kClassOf, 1);
+ JumpTarget leave, null, function, non_function_constructor;
+
+ // Load the object into r0.
+ LoadAndSpill(args->at(0));
+ frame_->EmitPop(r0);
+
+ // If the object is a smi, we return null.
+ __ tst(r0, Operand(kSmiTagMask));
+ null.Branch(eq);
+
+ // Check that the object is a JS object but take special care of JS
+ // functions to make sure they have 'Function' as their class.
+ __ CompareObjectType(r0, r0, r1, FIRST_JS_OBJECT_TYPE);
+ null.Branch(lt);
+
+ // As long as JS_FUNCTION_TYPE is the last instance type and it is
+ // right after LAST_JS_OBJECT_TYPE, we can avoid checking for
+ // LAST_JS_OBJECT_TYPE.
+ ASSERT(LAST_TYPE == JS_FUNCTION_TYPE);
+ ASSERT(JS_FUNCTION_TYPE == LAST_JS_OBJECT_TYPE + 1);
+ __ cmp(r1, Operand(JS_FUNCTION_TYPE));
+ function.Branch(eq);
+
+ // Check if the constructor in the map is a function.
+ __ ldr(r0, FieldMemOperand(r0, Map::kConstructorOffset));
+ __ CompareObjectType(r0, r1, r1, JS_FUNCTION_TYPE);
+ non_function_constructor.Branch(ne);
+
+ // The r0 register now contains the constructor function. Grab the
+ // instance class name from there.
+ __ ldr(r0, FieldMemOperand(r0, JSFunction::kSharedFunctionInfoOffset));
+ __ ldr(r0, FieldMemOperand(r0, SharedFunctionInfo::kInstanceClassNameOffset));
+ frame_->EmitPush(r0);
+ leave.Jump();
+
+ // Functions have class 'Function'.
+ function.Bind();
+ __ mov(r0, Operand(Factory::function_class_symbol()));
+ frame_->EmitPush(r0);
+ leave.Jump();
+
+ // Objects with a non-function constructor have class 'Object'.
+ non_function_constructor.Bind();
+ __ mov(r0, Operand(Factory::Object_symbol()));
frame_->EmitPush(r0);
+ leave.Jump();
+
+ // Non-JS objects have class null.
+ null.Bind();
+ __ mov(r0, Operand(Factory::null_value()));
+ frame_->EmitPush(r0);
+
+ // All done.
+ leave.Bind();
}
void CodeGenerator::GenerateClassOf(ZoneList<Expression*>* args) {
- // TODO(X64): Optimize this like it's done on IA-32.
ASSERT(args->length() == 1);
+ JumpTarget leave, null, function, non_function_constructor;
Load(args->at(0)); // Load the object.
- Result result = frame_->CallRuntime(Runtime::kClassOf, 1);
- frame_->Push(&result);
+ Result obj = frame_->Pop();
+ obj.ToRegister();
+ frame_->Spill(obj.reg());
+
+ // If the object is a smi, we return null.
+ __ testl(obj.reg(), Immediate(kSmiTagMask));
+ null.Branch(zero);
+
+ // Check that the object is a JS object but take special care of JS
+ // functions to make sure they have 'Function' as their class.
+ { Result tmp = allocator()->Allocate();
+ __ movq(obj.reg(), FieldOperand(obj.reg(), HeapObject::kMapOffset));
+ __ movb(tmp.reg(), FieldOperand(obj.reg(), Map::kInstanceTypeOffset));
+ __ cmpb(tmp.reg(), Immediate(FIRST_JS_OBJECT_TYPE));
+ null.Branch(less);
+
+ // As long as JS_FUNCTION_TYPE is the last instance type and it is
+ // right after LAST_JS_OBJECT_TYPE, we can avoid checking for
+ // LAST_JS_OBJECT_TYPE.
+ ASSERT(LAST_TYPE == JS_FUNCTION_TYPE);
+ ASSERT(JS_FUNCTION_TYPE == LAST_JS_OBJECT_TYPE + 1);
+ __ cmpb(tmp.reg(), Immediate(JS_FUNCTION_TYPE));
+ function.Branch(equal);
+ }
+
+ // Check if the constructor in the map is a function.
+ { Result tmp = allocator()->Allocate();
+ __ movq(obj.reg(), FieldOperand(obj.reg(), Map::kConstructorOffset));
+ __ CmpObjectType(obj.reg(), JS_FUNCTION_TYPE, tmp.reg());
+ non_function_constructor.Branch(not_equal);
+ }
+
+ // The obj register now contains the constructor function. Grab the
+ // instance class name from there.
+ __ movq(obj.reg(),
+ FieldOperand(obj.reg(), JSFunction::kSharedFunctionInfoOffset));
+ __ movq(obj.reg(),
+ FieldOperand(obj.reg(),
+ SharedFunctionInfo::kInstanceClassNameOffset));
+ frame_->Push(&obj);
+ leave.Jump();
+
+ // Functions have class 'Function'.
+ function.Bind();
+ frame_->Push(Factory::function_class_symbol());
+ leave.Jump();
+
+ // Objects with a non-function constructor have class 'Object'.
+ non_function_constructor.Bind();
+ frame_->Push(Factory::Object_symbol());
+ leave.Jump();
+
+ // Non-JS objects have class null.
+ null.Bind();
+ frame_->Push(Factory::null_value());
+
+ // All done.
+ leave.Bind();
}