Switch CallConstructStub to take new.target in register.

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 3253 matching lines @@
   PrepareForBailoutForId(expr->ReturnId(), TOS_REG);
   context()->Plug(rax);
 }
 
 
 void FullCodeGenerator::EmitSuperConstructorCall(Call* expr) {
   SuperCallReference* super_call_ref =
       expr->expression()->AsSuperCallReference();
   DCHECK_NOT_NULL(super_call_ref);
 
-  VariableProxy* new_target_proxy = super_call_ref->new_target_var();
-  VisitForStackValue(new_target_proxy);
-
   EmitLoadSuperConstructor(super_call_ref);
   __ Push(result_register());
 
   // Push the arguments ("left-to-right") on the stack.
   ZoneList<Expression*>* args = expr->arguments();
   int arg_count = args->length();
   for (int i = 0; i < arg_count; i++) {
     VisitForStackValue(args->at(i));
   }
 
   // Call the construct call builtin that handles allocation and
   // constructor invocation.
   SetConstructCallPosition(expr);
 
-  // Load function and argument count into edi and eax.
+  // Load original constructor into rcx.
+  VisitForAccumulatorValue(super_call_ref->new_target_var());
+  __ movp(rcx, result_register());
+
+  // Load function and argument count into rdi and rax.
   __ Set(rax, arg_count);
   __ movp(rdi, Operand(rsp, arg_count * kPointerSize));
 
   // Record call targets in unoptimized code.
   if (FLAG_pretenuring_call_new) {
     UNREACHABLE();
     /* TODO(dslomov): support pretenuring.
     EnsureSlotContainsAllocationSite(expr->AllocationSiteFeedbackSlot());
     DCHECK(expr->AllocationSiteFeedbackSlot().ToInt() ==
            expr->CallNewFeedbackSlot().ToInt() + 1);
     */
   }
 
   __ Move(rbx, FeedbackVector());
   __ Move(rdx, SmiFromSlot(expr->CallFeedbackSlot()));
 
   CallConstructStub stub(isolate(), SUPER_CALL_RECORD_TARGET);
   __ call(stub.GetCode(), RelocInfo::CONSTRUCT_CALL);
 
-  __ Drop(1);
-
   RecordJSReturnSite(expr);
 
   EmitInitializeThisAfterSuper(super_call_ref, expr->CallFeedbackICSlot());
   context()->Plug(rax);
 }
 
 
 void FullCodeGenerator::EmitIsSmi(CallRuntime* expr) {
   ZoneList<Expression*>* args = expr->arguments();
   DCHECK(args->length() == 1);
@@ skipping 902 matching lines @@
   DCHECK(args->length() == 2);
 
   // new.target
   VisitForStackValue(args->at(0));
 
   // .this_function
   VisitForStackValue(args->at(1));
   __ CallRuntime(Runtime::kGetPrototype, 1);
   __ Push(result_register());
 
+  // Load original constructor into rcx.
+  __ movp(rcx, Operand(rsp, 1 * kPointerSize));
+
   // Check if the calling frame is an arguments adaptor frame.
   Label adaptor_frame, args_set_up, runtime;
   __ movp(rdx, Operand(rbp, StandardFrameConstants::kCallerFPOffset));
-  __ movp(rcx, Operand(rdx, StandardFrameConstants::kContextOffset));
-  __ Cmp(rcx, Smi::FromInt(StackFrame::ARGUMENTS_ADAPTOR));
+  __ movp(rbx, Operand(rdx, StandardFrameConstants::kContextOffset));
+  __ Cmp(rbx, Smi::FromInt(StackFrame::ARGUMENTS_ADAPTOR));
   __ j(equal, &adaptor_frame);
   // 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);
+    __ movp(rbx, Operand(rdx, ArgumentsAdaptorFrameConstants::kLengthOffset));
+    __ SmiToInteger64(rbx, rbx);
 
-    __ movp(rax, rcx);
-    __ leap(rdx, Operand(rdx, rcx, times_pointer_size,
+    __ movp(rax, rbx);
+    __ leap(rdx, Operand(rdx, rbx, times_pointer_size,
                          StandardFrameConstants::kCallerSPOffset));
     Label loop;
     __ bind(&loop);
     __ Push(Operand(rdx, -1 * kPointerSize));
     __ subp(rdx, Immediate(kPointerSize));
-    __ decp(rcx);
+    __ decp(rbx);
     __ j(not_zero, &loop);
   }
 
   __ bind(&args_set_up);
   __ movp(rdi, Operand(rsp, rax, times_pointer_size, 0));
   __ LoadRoot(rbx, Heap::kUndefinedValueRootIndex);
 
   CallConstructStub stub(isolate(), SUPER_CONSTRUCTOR_CALL);
   __ call(stub.GetCode(), RelocInfo::CONSTRUCT_CALL);
 
@@ skipping 1263 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