[builtins] Add support for NewTarget to Execution::New.

src/x64/code-stubs-x64.cc

 // Copyright 2013 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #if V8_TARGET_ARCH_X64
 
 #include "src/bootstrapper.h"
 #include "src/code-stubs.h"
 #include "src/codegen.h"
 #include "src/ic/handler-compiler.h"
@@ skipping 1959 matching lines @@
   CallFunctionNoFeedback(masm, argc(), NeedsChecks(), CallAsMethod());
 }
 
 
 void CallConstructStub::Generate(MacroAssembler* masm) {
   // rax : number of arguments
   // rbx : feedback vector
   // rcx : original constructor (for IsSuperConstructorCall)
   // rdx : slot in feedback vector (Smi, for RecordCallTarget)
   // rdi : constructor function
-  Label slow, non_function_call;
 
-  // Check that function is not a smi.
-  __ JumpIfSmi(rdi, &non_function_call);
-  // Check that function is a JSFunction.
+  Label non_function;
+  // Check that the constructor is not a smi.
+  __ JumpIfSmi(rdi, &non_function);
+  // Check that constructor is a JSFunction.
   __ CmpObjectType(rdi, JS_FUNCTION_TYPE, r11);
-  __ j(not_equal, &slow);
+  __ j(not_equal, &non_function);
 
   if (RecordCallTarget()) {
     GenerateRecordCallTarget(masm, IsSuperConstructorCall());
 
     __ SmiToInteger32(rdx, rdx);
     Label feedback_register_initialized;
     // Put the AllocationSite from the feedback vector into rbx, or undefined.
     __ movp(rbx, FieldOperand(rbx, rdx, times_pointer_size,
                               FixedArray::kHeaderSize));
     __ CompareRoot(FieldOperand(rbx, 0), Heap::kAllocationSiteMapRootIndex);
     __ j(equal, &feedback_register_initialized);
     __ LoadRoot(rbx, Heap::kUndefinedValueRootIndex);
     __ bind(&feedback_register_initialized);
 
     __ AssertUndefinedOrAllocationSite(rbx);
   }
 
   // Pass original constructor to construct stub.
   if (IsSuperConstructorCall()) {
     __ movp(rdx, rcx);
   } else {
     __ movp(rdx, rdi);
   }
 
-  // Jump to the function-specific construct stub.
-  Register jmp_reg = rcx;
-  __ movp(jmp_reg, FieldOperand(rdi, JSFunction::kSharedFunctionInfoOffset));
-  __ movp(jmp_reg, FieldOperand(jmp_reg,
-                                SharedFunctionInfo::kConstructStubOffset));
-  __ leap(jmp_reg, FieldOperand(jmp_reg, Code::kHeaderSize));
-  __ jmp(jmp_reg);
+  // Tail call to the function-specific construct stub (still in the caller
+  // context at this point).
+  __ movp(rcx, FieldOperand(rdi, JSFunction::kSharedFunctionInfoOffset));
+  __ movp(rcx, FieldOperand(rcx, SharedFunctionInfo::kConstructStubOffset));
+  __ leap(rcx, FieldOperand(rcx, Code::kHeaderSize));
+  __ jmp(rcx);
 
-  // rdi: called object
-  // rax: number of arguments
-  // r11: object map
-  __ bind(&slow);
-  {
-    __ CmpInstanceType(r11, JS_FUNCTION_PROXY_TYPE);
-    __ j(not_equal, &non_function_call, Label::kNear);
-
-    // TODO(neis): This doesn't match the ES6 spec for [[Construct]] on proxies.
-    __ movp(rdi, FieldOperand(rdi, JSFunctionProxy::kConstructTrapOffset));
-    __ Jump(isolate()->builtins()->Call(), RelocInfo::CODE_TARGET);
-
-    __ bind(&non_function_call);
-    {
-      // Determine the delegate for the target (if any).
-      FrameScope scope(masm, StackFrame::INTERNAL);
-      __ Integer32ToSmi(rax, rax);
-      __ Push(rax);
-      __ Push(rdi);
-      __ CallRuntime(Runtime::kGetConstructorDelegate, 1);
-      __ movp(rdi, rax);
-      __ Pop(rax);
-      __ SmiToInteger32(rax, rax);
-    }
-    // The delegate is always a regular function.
-    __ AssertFunction(rdi);
-    __ Jump(isolate()->builtins()->CallFunction(), RelocInfo::CODE_TARGET);
-  }
+  __ bind(&non_function);
+  __ movp(rdx, rdi);
+  __ Jump(isolate()->builtins()->Construct(), RelocInfo::CODE_TARGET);
 }
 
 
 static void EmitLoadTypeFeedbackVector(MacroAssembler* masm, Register vector) {
   __ movp(vector, Operand(rbp, JavaScriptFrameConstants::kFunctionOffset));
   __ movp(vector, FieldOperand(vector, JSFunction::kSharedFunctionInfoOffset));
   __ movp(vector, FieldOperand(vector,
                                SharedFunctionInfo::kFeedbackVectorOffset));
 }
 
@@ skipping 3510 matching lines @@
                            kStackSpace, nullptr, return_value_operand, NULL);
 }
 
 
 #undef __
 
 }  // namespace internal
 }  // namespace v8
 
 #endif  // V8_TARGET_ARCH_X64