Remove dead code from InvokeDartCode stub.

runtime/vm/stub_code_x64.cc

 // Copyright (c) 2013, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 #include "vm/globals.h"
 #if defined(TARGET_ARCH_X64)
 
 #include "vm/assembler.h"
 #include "vm/compiler.h"
 #include "vm/dart_entry.h"
@@ skipping 729 matching lines @@
   const Register kNewContextReg = CallingConventions::kArg4Reg;
 
   // At this point, the stack looks like:
   // | saved RBP                                      | <-- RBP
   // | saved PC (return to DartEntry::InvokeFunction) |
 
   const intptr_t kInitialOffset = 1;
   // Save arguments descriptor array and new context.
   const intptr_t kArgumentsDescOffset = -(kInitialOffset) * kWordSize;
   __ pushq(kArgDescReg);
-  const intptr_t kNewContextOffset = -(kInitialOffset + 1) * kWordSize;
   __ pushq(kNewContextReg);
 
   // Save C++ ABI callee-saved registers.
   __ PushRegisters(CallingConventions::kCalleeSaveCpuRegisters,
                    CallingConventions::kCalleeSaveXmmRegisters);
 
   // We now load the pool pointer(PP) as we are about to invoke dart code and we
   // could potentially invoke some intrinsic functions which need the PP to be
   // set up.
   __ LoadPoolPointer(PP);
@@ skipping 97 matching lines @@
   __ Bind(&push_arguments);
   __ pushq(Address(RDX, RAX, TIMES_8, 0));
   __ incq(RAX);
   __ cmpq(RAX, RBX);
   __ j(LESS, &push_arguments, Assembler::kNearJump);
   __ Bind(&done_push_arguments);
 
   // Call the Dart code entrypoint.
   __ call(kEntryPointReg);  // R10 is the arguments descriptor array.
 
-  // Restore CTX from the saved context handle.
-  __ movq(CTX, Address(RBP, kNewContextOffset));
-  __ movq(CTX, Address(CTX, VMHandles::kOffsetOfRawPtrInHandle));
-
   // Read the saved arguments descriptor array to obtain the number of passed
   // arguments.
   __ movq(kArgDescReg, Address(RBP, kArgumentsDescOffset));
   __ movq(R10, Address(kArgDescReg, VMHandles::kOffsetOfRawPtrInHandle));
   __ movq(RDX, FieldAddress(R10, ArgumentsDescriptor::count_offset()));
   // Get rid of arguments pushed on the stack.
   __ leaq(RSP, Address(RSP, RDX, TIMES_4, 0));  // RDX is a Smi.
 
   __ LoadIsolate(kIsolateReg);
   // Restore the saved Context pointer into the Isolate structure.
@@ skipping 1163 matching lines @@
 
   __ movq(left, Address(RSP, 2 * kWordSize));
   __ movq(right, Address(RSP, 1 * kWordSize));
   GenerateIdenticalWithNumberCheckStub(assembler, left, right);
   __ ret();
 }
 
 }  // namespace dart
 
 #endif  // defined TARGET_ARCH_X64