Add runtime and native entry tags

runtime/vm/stub_code_mips.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_MIPS)
 
 #include "vm/assembler.h"
 #include "vm/code_generator.h"
 #include "vm/compiler.h"
@@ skipping 55 matching lines @@
   { Label ok;
     // Check that we are always entering from Dart code.
     __ lw(T0, Address(A0, Isolate::vm_tag_offset()));
     __ BranchEqual(T0, VMTag::kScriptTagId, &ok);
     __ Stop("Not coming from Dart code.");
     __ Bind(&ok);
   }
 #endif
 
   // Mark that the isolate is executing VM code.
-  __ LoadImmediate(T0, VMTag::kVMTagId);
-  __ sw(T0, Address(A0, Isolate::vm_tag_offset()));
+  __ sw(S5, Address(A0, 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(4 * kWordSize);  // Reserve space for arguments.
 
   // Pass NativeArguments structure by value and call runtime.
   // Registers A0, A1, A2, and A3 are used.
 
   ASSERT(isolate_offset == 0 * kWordSize);
@@ skipping 105 matching lines @@
   { Label ok;
     // Check that we are always entering from Dart code.
     __ lw(T0, Address(A0, Isolate::vm_tag_offset()));
     __ BranchEqual(T0, VMTag::kScriptTagId, &ok);
     __ Stop("Not coming from Dart code.");
     __ Bind(&ok);
   }
 #endif
 
   // Mark that the isolate is executing Native code.
-  __ LoadImmediate(T0, VMTag::kRuntimeNativeTagId);
-  __ sw(T0, Address(A0, Isolate::vm_tag_offset()));
+  __ sw(T5, Address(A0, Isolate::vm_tag_offset()));
 
   // Initialize NativeArguments structure and call native function.
   // Registers A0, A1, A2, and A3 are used.
 
   ASSERT(isolate_offset == 0 * kWordSize);
   // Set isolate in NativeArgs: A0 already contains CTX.
 
   // There are no native calls to closures, so we do not need to set the tag
   // bits kClosureFunctionBit and kInstanceFunctionBit in argc_tag_.
   ASSERT(argc_tag_offset == 1 * kWordSize);
@@ skipping 112 matching lines @@
   { Label ok;
     // Check that we are always entering from Dart code.
     __ lw(T0, Address(A0, Isolate::vm_tag_offset()));
     __ BranchEqual(T0, VMTag::kScriptTagId, &ok);
     __ Stop("Not coming from Dart code.");
     __ Bind(&ok);
   }
 #endif
 
   // Mark that the isolate is executing Native code.
-  __ LoadImmediate(T0, VMTag::kRuntimeNativeTagId);
-  __ sw(T0, Address(A0, Isolate::vm_tag_offset()));
+  __ sw(T5, Address(A0, Isolate::vm_tag_offset()));
 
   // Initialize NativeArguments structure and call native function.
   // Registers A0, A1, A2, and A3 are used.
 
   ASSERT(isolate_offset == 0 * kWordSize);
   // Set isolate in NativeArgs: A0 already contains CTX.
 
   // There are no native calls to closures, so we do not need to set the tag
   // bits kClosureFunctionBit and kInstanceFunctionBit in argc_tag_.
   ASSERT(argc_tag_offset == 1 * kWordSize);
@@ skipping 1751 matching lines @@
   const Register right = T0;
   __ lw(left, Address(SP, 1 * kWordSize));
   __ lw(right, Address(SP, 0 * kWordSize));
   GenerateIdenticalWithNumberCheckStub(assembler, left, right, temp1, temp2);
   __ Ret();
 }
 
 }  // namespace dart
 
 #endif  // defined TARGET_ARCH_MIPS