[Interpreter] Support for operator new.

src/x64/builtins-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.
 
 #if V8_TARGET_ARCH_X64
 
 #include "src/code-factory.h"
 #include "src/codegen.h"
 #include "src/deoptimizer.h"
 #include "src/full-codegen/full-codegen.h"
@@ skipping 777 matching lines @@
 // static
 void Builtins::Generate_InterpreterPushArgsAndCall(MacroAssembler* masm) {
   // ----------- S t a t e -------------
   //  -- rax : the number of arguments (not including the receiver)
   //  -- rbx : the address of the first argument to be pushed. Subsequent
   //           arguments should be consecutive above this, in the same order as
   //           they are to be pushed onto the stack.
   //  -- rdi : the target to call (can be any Object).
 
   // Pop return address to allow tail-call after pushing arguments.
-  __ Pop(rdx);
+  __ PopReturnAddressTo(kScratchRegister);
 
   // Find the address of the last argument.
   __ movp(rcx, rax);
   __ addp(rcx, Immediate(1));  // Add one for receiver.
   __ shlp(rcx, Immediate(kPointerSizeLog2));
   __ negp(rcx);
   __ addp(rcx, rbx);
 
   // Push the arguments.
   Label loop_header, loop_check;
   __ j(always, &loop_check);
   __ bind(&loop_header);
   __ Push(Operand(rbx, 0));
   __ subp(rbx, Immediate(kPointerSize));
   __ bind(&loop_check);
   __ cmpp(rbx, rcx);
   __ j(greater, &loop_header, Label::kNear);
 
   // Call the target.
-  __ Push(rdx);  // Re-push return address.
+  __ PushReturnAddressFrom(kScratchRegister);  // Re-push return address.
   __ Jump(masm->isolate()->builtins()->Call(), RelocInfo::CODE_TARGET);
 }
 
 
+// static
+void Builtins::Generate_InterpreterPushArgsAndConstruct(MacroAssembler* masm) {
+  // ----------- S t a t e -------------
+  //  -- rax : the number of arguments (not including the receiver)
+  //  -- rdx : the original constructor (either the same as the constructor or
+  //           the JSFunction on which new was invoked initially)
+  //  -- rdi : the constructor to call (can be any Object)
+  //  -- rbx : the address of the first argument to be pushed. Subsequent
+  //           arguments should be consecutive above this, in the same order as
+  //           they are to be pushed onto the stack.
+  // -----------------------------------
+
+  // Pop return address to allow tail-call after pushing arguments.
+  __ PopReturnAddressTo(kScratchRegister);
+
+  // Find the address of the last argument.
+  __ movp(rcx, rax);
+  __ addp(rcx, Immediate(1));  // Add one for receiver.
+  __ shlp(rcx, Immediate(kPointerSizeLog2));
+  __ negp(rcx);
+  __ addp(rcx, rbx);
+
+  // Push the arguments.
+  Label loop_header, loop_check;
+  __ j(always, &loop_check);
+  __ bind(&loop_header);
+  __ Push(Operand(rbx, 0));
+  __ subp(rbx, Immediate(kPointerSize));
+  __ bind(&loop_check);
+  __ cmpp(rbx, rcx);
+  __ j(greater, &loop_header, Label::kNear);
+
+  // Push return address in preparation for the tail-call.
+  __ PushReturnAddressFrom(kScratchRegister);

[rmcilroy, 2015/10/13 14:07:30]

nit - could we create a helper function for the arg pushing assembly which is
shared between PushArgsAndCall and PushArgsAndConstruct.

[oth, 2015/10/14 08:40:09]

Done.

+
+  // Call the target.
+  __ Jump(masm->isolate()->builtins()->Construct(), RelocInfo::CONSTRUCT_CALL);
+}
+
+
 void Builtins::Generate_CompileLazy(MacroAssembler* masm) {
   CallRuntimePassFunction(masm, Runtime::kCompileLazy);
   GenerateTailCallToReturnedCode(masm);
 }
 
 
 static void CallCompileOptimized(MacroAssembler* masm,
                                             bool concurrent) {
   FrameScope scope(masm, StackFrame::INTERNAL);
   // Push a copy of the function onto the stack.
@@ skipping 1100 matching lines @@
   __ ret(0);
 }
 
 
 #undef __
 
 }  // namespace internal
 }  // namespace v8
 
 #endif  // V8_TARGET_ARCH_X64