Add runtime and native entry tags

runtime/vm/stub_code_arm.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_ARM)
 
 #include "vm/assembler.h"
 #include "vm/code_generator.h"
 #include "vm/compiler.h"
@@ skipping 52 matching lines @@
     // Check that we are always entering from Dart code.
     __ LoadFromOffset(kWord, R6, CTX, Isolate::vm_tag_offset());
     __ CompareImmediate(R6, VMTag::kScriptTagId);
     __ b(&ok, EQ);
     __ Stop("Not coming from Dart code.");
     __ Bind(&ok);
   }
 #endif
 
   // Mark that the isolate is executing VM code.
-  __ LoadImmediate(R6, VMTag::kVMTagId);
-  __ StoreToOffset(kWord, R6, CTX, Isolate::vm_tag_offset());
+  __ StoreToOffset(kWord, R5, CTX, Isolate::vm_tag_offset());
 
   // Reserve space for arguments and align frame before entering C++ world.
   // NativeArguments are passed in registers.
   ASSERT(sizeof(NativeArguments) == 4 * kWordSize);
   __ ReserveAlignedFrameSpace(0);
 
   // Pass NativeArguments structure by value and call runtime.
   // Registers R0, R1, R2, and R3 are used.
 
   ASSERT(isolate_offset == 0 * kWordSize);
@@ skipping 93 matching lines @@
     // Check that we are always entering from Dart code.
     __ LoadFromOffset(kWord, R6, CTX, Isolate::vm_tag_offset());
     __ CompareImmediate(R6, VMTag::kScriptTagId);
     __ b(&ok, EQ);
     __ Stop("Not coming from Dart code.");
     __ Bind(&ok);
   }
 #endif
 
   // Mark that the isolate is executing Native code.
-  __ LoadImmediate(R6, VMTag::kRuntimeNativeTagId);
-  __ StoreToOffset(kWord, R6, CTX, Isolate::vm_tag_offset());
+  __ StoreToOffset(kWord, R5, CTX, Isolate::vm_tag_offset());
 
   // Reserve space for the native arguments structure passed on the stack (the
   // outgoing pointer parameter to the native arguments structure is passed in
   // R0) and align frame before entering the C++ world.
   __ ReserveAlignedFrameSpace(sizeof(NativeArguments));
 
   // Initialize NativeArguments structure and call native function.
   // Registers R0, R1, R2, and R3 are used.
 
   ASSERT(isolate_offset == 0 * kWordSize);
@@ skipping 100 matching lines @@
     // Check that we are always entering from Dart code.
     __ LoadFromOffset(kWord, R6, CTX, Isolate::vm_tag_offset());
     __ CompareImmediate(R6, VMTag::kScriptTagId);
     __ b(&ok, EQ);
     __ Stop("Not coming from Dart code.");
     __ Bind(&ok);
   }
 #endif
 
   // Mark that the isolate is executing Native code.
-  __ LoadImmediate(R6, VMTag::kRuntimeNativeTagId);
-  __ StoreToOffset(kWord, R6, CTX, Isolate::vm_tag_offset());
+  __ StoreToOffset(kWord, R5, CTX, Isolate::vm_tag_offset());
 
   // Reserve space for the native arguments structure passed on the stack (the
   // outgoing pointer parameter to the native arguments structure is passed in
   // R0) and align frame before entering the C++ world.
   __ ReserveAlignedFrameSpace(sizeof(NativeArguments));
 
   // Initialize NativeArguments structure and call native function.
   // Registers R0, R1, R2, and R3 are used.
 
   ASSERT(isolate_offset == 0 * kWordSize);
@@ skipping 1530 matching lines @@
   const Register right = R0;
   __ ldr(left, Address(SP, 1 * kWordSize));
   __ ldr(right, Address(SP, 0 * kWordSize));
   GenerateIdenticalWithNumberCheckStub(assembler, left, right, temp);
   __ Ret();
 }
 
 }  // namespace dart
 
 #endif  // defined TARGET_ARCH_ARM