Do not add extra argument for new.target

src/x64/full-codegen-x64.cc

 // Copyright 2012 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.
 
 #include "src/v8.h"
 
 #if V8_TARGET_ARCH_X64
 
 #include "src/code-factory.h"
 #include "src/code-stubs.h"
@@ skipping 223 matching lines @@
   // derived constructors with super calls.
   Variable* this_function_var = scope()->this_function_var();
   if (this_function_var != nullptr) {
     Comment cmnt(masm_, "[ This function");
     SetVar(this_function_var, rdi, rbx, rdx);
   }
 
   Variable* new_target_var = scope()->new_target_var();
   if (new_target_var != nullptr) {
     Comment cmnt(masm_, "[ new.target");
-    // new.target is parameter -2.
-    int offset = 2 * kPointerSize + kFPOnStackSize + kPCOnStackSize +
-                 (info_->scope()->num_parameters() - 1) * kPointerSize;
-    __ movp(rax, Operand(rbp, offset));
+
+    __ movp(rax, Operand(rbp, StandardFrameConstants::kCallerFPOffset));
+    Label non_adaptor_frame;
+    __ Cmp(Operand(rax, StandardFrameConstants::kContextOffset),
+           Smi::FromInt(StackFrame::ARGUMENTS_ADAPTOR));
+    __ j(not_equal, &non_adaptor_frame);
+    __ movp(rax, Operand(rax, StandardFrameConstants::kCallerFPOffset));
+
+    __ bind(&non_adaptor_frame);
+    __ Cmp(Operand(rax, StandardFrameConstants::kMarkerOffset),
+           Smi::FromInt(StackFrame::CONSTRUCT));
+
+    Label non_construct_frame, done;
+    __ j(not_equal, &non_construct_frame);
+
+    // Construct frame
+    __ movp(rax, Operand(rax, StandardFrameConstants::kExpressionsOffset -
+                                  2 * kPointerSize));
+    __ jmp(&done);
+
+    // Non-construct frame
+    __ bind(&non_construct_frame);
+    __ LoadRoot(rax, Heap::kUndefinedValueRootIndex);
+
+    __ bind(&done);
     SetVar(new_target_var, rax, rbx, rdx);
   }
 
-  ArgumentsAccessStub::HasNewTarget has_new_target =
-      IsSubclassConstructor(info->function()->kind())
-          ? ArgumentsAccessStub::HAS_NEW_TARGET
-          : ArgumentsAccessStub::NO_NEW_TARGET;
-
   // Possibly allocate RestParameters
   int rest_index;
   Variable* rest_param = scope()->rest_parameter(&rest_index);
   if (rest_param) {
     Comment cmnt(masm_, "[ Allocate rest parameter array");
 
     int num_parameters = info->scope()->num_parameters();
     int offset = num_parameters * kPointerSize;
-    if (has_new_target == ArgumentsAccessStub::HAS_NEW_TARGET) {
-      --num_parameters;
-      ++rest_index;
-    }
 
     __ leap(rdx,
             Operand(rbp, StandardFrameConstants::kCallerSPOffset + offset));
     __ Push(rdx);
     __ Push(Smi::FromInt(num_parameters));
     __ Push(Smi::FromInt(rest_index));
     __ Push(Smi::FromInt(language_mode()));
 
     RestParamAccessStub stub(isolate());
     __ CallStub(&stub);
@@ skipping 25 matching lines @@
     // stack frame was an arguments adapter frame.
 
     ArgumentsAccessStub::Type type;
     if (is_strict(language_mode()) || !is_simple_parameter_list()) {
       type = ArgumentsAccessStub::NEW_STRICT;
     } else if (function()->has_duplicate_parameters()) {
       type = ArgumentsAccessStub::NEW_SLOPPY_SLOW;
     } else {
       type = ArgumentsAccessStub::NEW_SLOPPY_FAST;
     }
-    ArgumentsAccessStub stub(isolate(), type, has_new_target);
+    ArgumentsAccessStub stub(isolate(), type);
     __ CallStub(&stub);
 
     SetVar(arguments, rax, rbx, rdx);
   }
 
   if (FLAG_trace) {
     __ CallRuntime(Runtime::kTraceEnter, 0);
   }
 
   // Visit the declarations and body unless there is an illegal
@@ skipping 134 matching lines @@
 #endif
     CodeGenerator::RecordPositions(masm_, function()->end_position() - 1);
     __ RecordJSReturn();
     // Do not use the leave instruction here because it is too short to
     // patch with the code required by the debugger.
     __ movp(rsp, rbp);
     __ popq(rbp);
     int no_frame_start = masm_->pc_offset();
 
     int arg_count = info_->scope()->num_parameters() + 1;
-    if (IsSubclassConstructor(info_->function()->kind())) {
-      arg_count++;
-    }
     int arguments_bytes = arg_count * kPointerSize;
     __ Ret(arguments_bytes, rcx);
 
     // Add padding that will be overwritten by a debugger breakpoint.  We
     // have just generated at least 7 bytes: "movp rsp, rbp; pop rbp; ret k"
     // (3 + 1 + 3) for x64 and at least 6 (2 + 1 + 3) bytes for x32.
     const int kPadding = Assembler::kJSReturnSequenceLength -
                          kPointerSize == kInt64Size ? 7 : 6;
     for (int i = 0; i < kPadding; ++i) {
       masm_->int3();
@@ skipping 3686 matching lines @@
   // default constructor has no arguments, so no adaptor frame means no args.
   __ movp(rax, Immediate(0));
   __ jmp(&args_set_up);
 
   // Copy arguments from adaptor frame.
   {
     __ bind(&adaptor_frame);
     __ movp(rcx, Operand(rdx, ArgumentsAdaptorFrameConstants::kLengthOffset));
     __ SmiToInteger64(rcx, rcx);
 
-    // Subtract 1 from arguments count, for new.target.
-    __ subp(rcx, Immediate(1));
     __ movp(rax, rcx);
     __ leap(rdx, Operand(rdx, rcx, times_pointer_size,
                          StandardFrameConstants::kCallerSPOffset));
     Label loop;
     __ bind(&loop);
     __ Push(Operand(rdx, -1 * kPointerSize));
     __ subp(rdx, Immediate(kPointerSize));
     __ decp(rcx);
     __ j(not_zero, &loop);
   }
@@ skipping 1307 matching lines @@
             Assembler::target_address_at(call_target_address,
                                          unoptimized_code));
   return OSR_AFTER_STACK_CHECK;
 }
 
 
 }  // namespace internal
 }  // namespace v8
 
 #endif  // V8_TARGET_ARCH_X64