Deoptimizer support for hydrogen stubs that accept a variable number of arguments.

src/x64/code-stubs-x64.cc

 // Copyright 2012 the V8 project authors. All rights reserved.
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 //     * Redistributions of source code must retain the above copyright
 //       notice, this list of conditions and the following disclaimer.
 //     * Redistributions in binary form must reproduce the above
 //       copyright notice, this list of conditions and the following
 //       disclaimer in the documentation and/or other materials provided
@@ skipping 77 matching lines @@
     CodeStubInterfaceDescriptor* descriptor) {
   // register state
   // rdi -- constructor function
   // rbx -- type info cell with elements kind
   // rax -- number of arguments to the constructor function
   static Register registers[] = { rdi, rbx };
   descriptor->register_param_count_ = 2;
   // stack param count needs (constructor pointer, and single argument)
   descriptor->stack_parameter_count_ = &rax;
   descriptor->register_params_ = registers;
-  descriptor->extra_expression_stack_count_ = 1;
+  descriptor->function_mode_ = JS_FUNCTION_STUB_MODE;
   descriptor->deoptimization_handler_ =
       FUNCTION_ADDR(ArrayConstructor_StubFailure);
 }
 
 
 void ArrayNoArgumentConstructorStub::InitializeInterfaceDescriptor(
     Isolate* isolate,
     CodeStubInterfaceDescriptor* descriptor) {
   InitializeArrayConstructorDescriptor(isolate, descriptor);
 }
@@ skipping 6667 matching lines @@
 
 void StubFailureTrampolineStub::Generate(MacroAssembler* masm) {
   ASSERT(!Serializer::enabled());
   CEntryStub ces(1, kSaveFPRegs);
   __ Call(ces.GetCode(masm->isolate()), RelocInfo::CODE_TARGET);
   int parameter_count_offset =
       StubFailureTrampolineFrame::kCallerStackParameterCountFrameOffset;
   __ movq(rbx, MemOperand(rbp, parameter_count_offset));
   masm->LeaveFrame(StackFrame::STUB_FAILURE_TRAMPOLINE);
   __ pop(rcx);
-  __ lea(rsp, MemOperand(rsp, rbx, times_pointer_size,
-                         extra_expression_stack_count_ * kPointerSize));
+  int additional_offset = function_mode_ == JS_FUNCTION_STUB_MODE
+      ? kPointerSize
+      : 0;
+  __ lea(rsp, MemOperand(rsp, rbx, times_pointer_size, additional_offset));
   __ jmp(rcx);  // Return to IC Miss stub, continuation still on stack.
 }
 
 
 void ProfileEntryHookStub::MaybeCallEntryHook(MacroAssembler* masm) {
   if (entry_hook_ != NULL) {
     ProfileEntryHookStub stub;
     masm->CallStub(&stub);
   }
 }
@@ skipping 56 matching lines @@
 #endif
 
   __ Ret();
 }
 
 #undef __
 
 } }  // namespace v8::internal
 
 #endif  // V8_TARGET_ARCH_X64