// Allocated the JSObject, now initialize the fields and add the heap tag.
// ebx: initial map
- // edx: JSObject
+ // edx: JSObject (untagged)
__ mov(Operand(edx, JSObject::kMapOffset), ebx);
__ mov(ebx, Factory::empty_fixed_array());
__ mov(Operand(edx, JSObject::kPropertiesOffset), ebx);
__ mov(Operand(edx, JSObject::kElementsOffset), ebx);
- __ or_(Operand(edx), Immediate(kHeapObjectTag));
// Push the allocated object to the stack. This is the object that will be
- // returned.
+ // returned (after it is tagged).
__ push(edx);
// eax: argc
- // edx: JSObject
+ // edx: JSObject (untagged)
// Load the address of the first in-object property into edx.
__ lea(edx, Operand(edx, JSObject::kHeaderSize));
- __ xor_(Operand(edx), Immediate(kHeapObjectTag)); // Clear heap object tag.
// Calculate the location of the first argument. The stack contains the
// allocated object and the return address on top of the argc arguments.
__ lea(ecx, Operand(esp, eax, times_4, 1 * kPointerSize));
__ mov(Operand(edx, i * kPointerSize), edi);
}
- // Move argc to ebx and retreive the JSObject to return.
+ // Move argc to ebx and retrieve and tag the JSObject to return.
__ mov(ebx, eax);
__ pop(eax);
+ __ or_(Operand(eax), Immediate(kHeapObjectTag));
// Remove caller arguments and receiver from the stack and return.
__ pop(ecx);
}
+// Specialized stub for constructing objects from functions which only have only
+// simple assignments of the form this.x = ...; in their body.
Object* ConstructStubCompiler::CompileConstructStub(
SharedFunctionInfo* shared) {
- // Not implemented yet - just jump to generic stub.
+ // ----------- S t a t e -------------
+ // -- rax : argc
+ // -- rdi : constructor
+ // -- rsp[0] : return address
+ // -- rsp[4] : last argument
+ // -----------------------------------
+ Label generic_stub_call;
+
+ // Use r8 for holding undefined which is used in several places below.
+ __ Move(r8, Factory::undefined_value());
+
+#ifdef ENABLE_DEBUGGER_SUPPORT
+ // Check to see whether there are any break points in the function code. If
+ // there are jump to the generic constructor stub which calls the actual
+ // code for the function thereby hitting the break points.
+ __ movq(rbx, FieldOperand(rdi, JSFunction::kSharedFunctionInfoOffset));
+ __ movq(rbx, FieldOperand(rbx, SharedFunctionInfo::kDebugInfoOffset));
+ __ cmpq(rbx, r8);
+ __ j(not_equal, &generic_stub_call);
+#endif
+
+ // Load the initial map and verify that it is in fact a map.
+ __ movq(rbx, FieldOperand(rdi, JSFunction::kPrototypeOrInitialMapOffset));
+ // Will both indicate a NULL and a Smi.
+ __ testq(rbx, Immediate(kSmiTagMask));
+ __ j(zero, &generic_stub_call);
+ __ CmpObjectType(rbx, MAP_TYPE, rcx);
+ __ j(not_equal, &generic_stub_call);
+
+#ifdef DEBUG
+ // Cannot construct functions this way.
+ // rdi: constructor
+ // rbx: initial map
+ __ CmpInstanceType(rbx, JS_FUNCTION_TYPE);
+ __ Assert(not_equal, "Function constructed by construct stub.");
+#endif
+
+ // Now allocate the JSObject in new space.
+ // rdi: constructor
+ // rbx: initial map
+ __ movzxbq(rcx, FieldOperand(rbx, Map::kInstanceSizeOffset));
+ __ shl(rcx, Immediate(kPointerSizeLog2));
+ // Make sure that the maximum heap object size will never cause us
+ // problems here.
+ ASSERT(Heap::MaxObjectSizeInPagedSpace() >= JSObject::kMaxInstanceSize);
+ __ AllocateObjectInNewSpace(rcx, rdx, rcx, no_reg, &generic_stub_call, false);
+
+ // Allocated the JSObject, now initialize the fields and add the heap tag.
+ // rbx: initial map
+ // rdx: JSObject (untagged)
+ __ movq(Operand(rdx, JSObject::kMapOffset), rbx);
+ __ Move(rbx, Factory::empty_fixed_array());
+ __ movq(Operand(rdx, JSObject::kPropertiesOffset), rbx);
+ __ movq(Operand(rdx, JSObject::kElementsOffset), rbx);
+
+ // rax: argc
+ // rdx: JSObject (untagged)
+ // Load the address of the first in-object property into r9.
+ __ lea(r9, Operand(rdx, JSObject::kHeaderSize));
+ // Calculate the location of the first argument. The stack contains only the
+ // return address on top of the argc arguments.
+ __ lea(rcx, Operand(rsp, rax, times_pointer_size, 0));
+
+ // rax: argc
+ // rcx: first argument
+ // rdx: JSObject (untagged)
+ // r8: undefined
+ // r9: first in-object property of the JSObject
+ // Fill the initialized properties with a constant value or a passed argument
+ // depending on the this.x = ...; assignment in the function.
+ for (int i = 0; i < shared->this_property_assignments_count(); i++) {
+ if (shared->IsThisPropertyAssignmentArgument(i)) {
+ Label not_passed;
+ // Set the property to undefined.
+ __ movq(Operand(r9, i * kPointerSize), r8);
+ // Check if the argument assigned to the property is actually passed.
+ int arg_number = shared->GetThisPropertyAssignmentArgument(i);
+ __ cmpq(rax, Immediate(arg_number));
+ __ j(below_equal, ¬_passed);
+ // Argument passed - find it on the stack.
+ __ movq(rbx, Operand(rcx, arg_number * -kPointerSize));
+ __ movq(Operand(r9, i * kPointerSize), rbx);
+ __ bind(¬_passed);
+ } else {
+ // Set the property to the constant value.
+ Handle<Object> constant(shared->GetThisPropertyAssignmentConstant(i));
+ __ Move(Operand(r9, i * kPointerSize), constant);
+ }
+ }
+
+ // Fill the unused in-object property fields with undefined.
+ for (int i = shared->this_property_assignments_count();
+ i < shared->CalculateInObjectProperties();
+ i++) {
+ __ movq(Operand(r9, i * kPointerSize), r8);
+ }
+
+ // rax: argc
+ // rdx: JSObject (untagged)
+ // Move argc to rbx and the JSObject to return to rax and tag it.
+ __ movq(rbx, rax);
+ __ movq(rax, rdx);
+ __ or_(rax, Immediate(kHeapObjectTag));
+
+ // rax: JSObject
+ // rbx: argc
+ // Remove caller arguments and receiver from the stack and return.
+ __ pop(rcx);
+ __ lea(rsp, Operand(rsp, rbx, times_pointer_size, 1 * kPointerSize));
+ __ push(rcx);
+ __ IncrementCounter(&Counters::constructed_objects, 1);
+ __ IncrementCounter(&Counters::constructed_objects_stub, 1);
+ __ ret(0);
+
+ // Jump to the generic stub in case the specialized code cannot handle the
+ // construction.
+ __ bind(&generic_stub_call);
Code* code = Builtins::builtin(Builtins::JSConstructStubGeneric);
Handle<Code> generic_construct_stub(code);
__ Jump(generic_construct_stub, RelocInfo::CODE_TARGET);