Add runtime and native entry tags

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 52 matching lines @@
     // Check that we are always entering from Dart code.
     __ movq(RAX, Immediate(VMTag::kScriptTagId));
     __ cmpq(RAX, Address(CTX, Isolate::vm_tag_offset()));
     __ j(EQUAL, &ok, Assembler::kNearJump);
     __ Stop("Not coming from Dart code.");
     __ Bind(&ok);
   }
 #endif
 
   // Mark that the isolate is executing VM code.
-  __ movq(Address(CTX, Isolate::vm_tag_offset()), Immediate(VMTag::kVMTagId));
+  __ movq(Address(CTX, Isolate::vm_tag_offset()), RBX);
 
   // Reserve space for arguments and align frame before entering C++ world.
   __ subq(RSP, Immediate(sizeof(NativeArguments)));
   if (OS::ActivationFrameAlignment() > 1) {
     __ andq(RSP, Immediate(~(OS::ActivationFrameAlignment() - 1)));
   }
 
   // Pass NativeArguments structure by value and call runtime.
   __ movq(Address(RSP, isolate_offset), CTX);  // Set isolate in NativeArgs.
   // There are no runtime calls to closures, so we do not need to set the tag
@@ skipping 84 matching lines @@
     // Check that we are always entering from Dart code.
     __ movq(R8, Immediate(VMTag::kScriptTagId));
     __ cmpq(R8, Address(CTX, Isolate::vm_tag_offset()));
     __ j(EQUAL, &ok, Assembler::kNearJump);
     __ Stop("Not coming from Dart code.");
     __ Bind(&ok);
   }
 #endif
 
   // Mark that the isolate is executing Native code.
-  __ movq(Address(CTX, Isolate::vm_tag_offset()),
-          Immediate(VMTag::kRuntimeNativeTagId));
+  __ movq(Address(CTX, Isolate::vm_tag_offset()), RBX);
 
   // Reserve space for the native arguments structure passed on the stack (the
   // outgoing pointer parameter to the native arguments structure is passed in
   // RDI) and align frame before entering the C++ world.
   __ subq(RSP, Immediate(sizeof(NativeArguments)));
   if (OS::ActivationFrameAlignment() > 1) {
     __ andq(RSP, Immediate(~(OS::ActivationFrameAlignment() - 1)));
   }
 
   // Pass NativeArguments structure by value and call native function.
@@ skipping 75 matching lines @@
     // Check that we are always entering from Dart code.
     __ movq(R8, Immediate(VMTag::kScriptTagId));
     __ cmpq(R8, Address(CTX, Isolate::vm_tag_offset()));
     __ j(EQUAL, &ok, Assembler::kNearJump);
     __ Stop("Not coming from Dart code.");
     __ Bind(&ok);
   }
 #endif
 
   // Mark that the isolate is executing Native code.
-  __ movq(Address(CTX, Isolate::vm_tag_offset()),
-          Immediate(VMTag::kRuntimeNativeTagId));
+  __ movq(Address(CTX, Isolate::vm_tag_offset()), RBX);
 
   // Reserve space for the native arguments structure passed on the stack (the
   // outgoing pointer parameter to the native arguments structure is passed in
   // RDI) and align frame before entering the C++ world.
   __ subq(RSP, Immediate(sizeof(NativeArguments)));
   if (OS::ActivationFrameAlignment() > 1) {
     __ andq(RSP, Immediate(~(OS::ActivationFrameAlignment() - 1)));
   }
 
   // Pass NativeArguments structure by value and call native function.
@@ skipping 1556 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