Do not add extra argument for new.target

src/mips/full-codegen-mips.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_MIPS
 
 // Note on Mips implementation:
 //
@@ skipping 240 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, a1, a2, a3);
   }
 
   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 +
-                 (info_->scope()->num_parameters() + 1) * kPointerSize;
-    __ lw(v0, MemOperand(fp, offset));
+
+    // Get the frame pointer for the calling frame.
+    __ lw(a2, MemOperand(fp, StandardFrameConstants::kCallerFPOffset));
+
+    // Skip the arguments adaptor frame if it exists.
+    Label check_frame_marker;
+    __ lw(a1, MemOperand(a2, StandardFrameConstants::kContextOffset));
+    __ Branch(&check_frame_marker, ne, a1,
+              Operand(Smi::FromInt(StackFrame::ARGUMENTS_ADAPTOR)));
+    __ lw(a2, MemOperand(a2, StandardFrameConstants::kCallerFPOffset));
+
+    // Check the marker in the calling frame.
+    __ bind(&check_frame_marker);
+    __ lw(a1, MemOperand(a2, StandardFrameConstants::kMarkerOffset));
+
+    Label non_construct_frame, done;
+    __ Branch(&non_construct_frame, ne, a1,
+              Operand(Smi::FromInt(StackFrame::CONSTRUCT)));
+
+    __ lw(v0, MemOperand(a2, StandardFrameConstants::kExpressionsOffset -
+                                 2 * kPointerSize));
+    __ Branch(&done);
+
+    __ bind(&non_construct_frame);
+    __ LoadRoot(v0, Heap::kUndefinedValueRootIndex);
+    __ bind(&done);
+
     SetVar(new_target_var, v0, a2, a3);
   }
 
-  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;
-    }
 
     __ Addu(a3, fp,
             Operand(StandardFrameConstants::kCallerSPOffset + offset));
     __ li(a2, Operand(Smi::FromInt(num_parameters)));
     __ li(a1, Operand(Smi::FromInt(rest_index)));
     __ li(a0, Operand(Smi::FromInt(language_mode())));
     __ Push(a3, a2, a1, a0);
 
     RestParamAccessStub stub(isolate());
     __ CallStub(&stub);
@@ skipping 24 matching lines @@
     // The stub will rewrite receiever and parameter count if the previous
     // 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, v0, a1, a2);
   }
 
   if (FLAG_trace) {
     __ CallRuntime(Runtime::kTraceEnter, 0);
   }
 
   // Visit the declarations and body unless there is an illegal
@@ skipping 140 matching lines @@
     // Add a label for checking the size of the code used for returning.
     Label check_exit_codesize;
     masm_->bind(&check_exit_codesize);
 #endif
     // Make sure that the constant pool is not emitted inside of the return
     // sequence.
     { Assembler::BlockTrampolinePoolScope block_trampoline_pool(masm_);
       // Here we use masm_-> instead of the __ macro to avoid the code coverage
       // tool from instrumenting as we rely on the code size here.
       int32_t arg_count = info_->scope()->num_parameters() + 1;
-      if (IsSubclassConstructor(info_->function()->kind())) {
-        arg_count++;
-      }
       int32_t sp_delta = arg_count * kPointerSize;
       CodeGenerator::RecordPositions(masm_, function()->end_position() - 1);
       __ RecordJSReturn();
       masm_->mov(sp, fp);
       int no_frame_start = masm_->pc_offset();
       masm_->MultiPop(static_cast<RegList>(fp.bit() | ra.bit()));
       masm_->Addu(sp, sp, Operand(sp_delta));
       masm_->Jump(ra);
       info_->AddNoFrameRange(no_frame_start, masm_->pc_offset());
     }
@@ skipping 3770 matching lines @@
   // default constructor has no arguments, so no adaptor frame means no args.
   __ mov(a0, zero_reg);
   __ Branch(&args_set_up);
 
   // Copy arguments from adaptor frame.
   {
     __ bind(&adaptor_frame);
     __ lw(a1, MemOperand(a2, ArgumentsAdaptorFrameConstants::kLengthOffset));
     __ SmiUntag(a1, a1);
 
-    // Subtract 1 from arguments count, for new.target.
-    __ Addu(a1, a1, Operand(-1));
     __ mov(a0, a1);
 
     // Get arguments pointer in a2.
     __ sll(at, a1, kPointerSizeLog2);
     __ addu(a2, a2, at);
     __ Addu(a2, a2, Operand(StandardFrameConstants::kCallerSPOffset));
     Label loop;
     __ bind(&loop);
     // Pre-decrement a2 with kPointerSize on each iteration.
     // Pre-decrement in order to skip receiver.
@@ skipping 1258 matching lines @@
          reinterpret_cast<uint32_t>(
              isolate->builtins()->OsrAfterStackCheck()->entry()));
   return OSR_AFTER_STACK_CHECK;
 }
 
 
 }  // namespace internal
 }  // namespace v8
 
 #endif  // V8_TARGET_ARCH_MIPS