Deletion barrier: Distinguish+verify field initialization in ia32 generated code.

runtime/vm/intrinsifier_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"  // Needed here to get TARGET_ARCH_X64.
 #if defined(TARGET_ARCH_X64)
 
 #include "vm/intrinsifier.h"
 
 #include "vm/assembler.h"
@@ skipping 72 matching lines @@
 
   // RAX: new growable array object start as a tagged pointer.
   // Store the type argument field in the growable array object.
   __ movq(RCX, Address(RSP, kTypeArgumentsOffset));  // type argument.
   __ StoreIntoObjectNoBarrier(
       RAX,
       FieldAddress(RAX, GrowableObjectArray::type_arguments_offset()),
       RCX);
 
   // Set the length field in the growable array object to 0.
-  __ ZeroSmiField(FieldAddress(RAX, GrowableObjectArray::length_offset()));
+  __ ZeroInitSmiField(FieldAddress(RAX, GrowableObjectArray::length_offset()));
   __ ret();  // returns the newly allocated object in RAX.
 
   __ Bind(&fall_through);
 }
 
 
 // Access growable object array at specified index.
 // On stack: growable array (+2), index (+1), return-address (+0).
 void Intrinsifier::GrowableArrayGetIndexed(Assembler* assembler) {
   Label fall_through;
@@ skipping 1671 matching lines @@
     __ orq(RDI, Immediate(RawObject::ClassIdTag::encode(cid)));
     __ movq(FieldAddress(RAX, String::tags_offset()), RDI);  // Tags.
   }
 
   // Set the length field.
   __ popq(RDI);
   __ StoreIntoObjectNoBarrier(RAX,
                               FieldAddress(RAX, String::length_offset()),
                               RDI);
   // Clear hash.
-  __ ZeroSmiField(FieldAddress(RAX, String::hash_offset()));
+  __ ZeroInitSmiField(FieldAddress(RAX, String::hash_offset()));
   __ jmp(ok, Assembler::kNearJump);
 
   __ Bind(&pop_and_fail);
   __ popq(RDI);
   __ jmp(failure);
 }
 
 
 // Arg0: OneByteString (receiver).
 // Arg1: Start index as Smi.
@@ skipping 213 matching lines @@
   // Set return value to Isolate::current_tag_.
   __ movq(RAX, Address(RBX, Isolate::current_tag_offset()));
   __ ret();
 }
 
 #undef __
 
 }  // namespace dart
 
 #endif  // defined TARGET_ARCH_X64