Expand the class id to 32 bits and size field to 16 bits on 64-bit platforms.

runtime/vm/intermediate_language_ia32.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_IA32.
 #if defined(TARGET_ARCH_IA32)
 
 #include "vm/intermediate_language.h"
 
 #include "vm/dart_entry.h"
@@ skipping 1401 matching lines @@
 
   for (intptr_t i = 0; i < num_temps; i++) {
     summary->set_temp(i, Location::RequiresRegister());
   }
 
   return summary;
 }
 
 
 void GuardFieldClassInstr::EmitNativeCode(FlowGraphCompiler* compiler) {
+  ASSERT(sizeof(classid_t) == 2);

[siva, 2015/06/12 22:08:11]

Ditto here and elsewhere.

   const intptr_t value_cid = value()->Type()->ToCid();
   const intptr_t field_cid = field().guarded_cid();
   const intptr_t nullability = field().is_nullable() ? kNullCid : kIllegalCid;
 
   if (field_cid == kDynamicCid) {
     ASSERT(!compiler->is_optimizing());
     return;  // Nothing to emit.
   }
 
   const bool emit_full_guard =
@@ skipping 327 matching lines @@
   __ movl(temp, box_reg);
   __ StoreIntoObject(instance_reg,
                      FieldAddress(instance_reg, offset),
                      temp);
 
   __ Bind(&done);
 }
 
 
 void StoreInstanceFieldInstr::EmitNativeCode(FlowGraphCompiler* compiler) {
+  ASSERT(sizeof(classid_t) == 2);
   Label skip_store;
 
   Register instance_reg = locs()->in(0).reg();
 
   if (IsUnboxedStore() && compiler->is_optimizing()) {
     XmmRegister value = locs()->in(1).fpu_reg();
     Register temp = locs()->temp(0).reg();
     Register temp2 = locs()->temp(1).reg();
     const intptr_t cid = field().UnboxedFieldCid();
 
@@ skipping 382 matching lines @@
     locs->set_temp(0, opt ? Location::RequiresFpuRegister()
                           : Location::FpuRegisterLocation(XMM1));
     locs->set_temp(1, Location::RequiresRegister());
   }
   locs->set_out(0, Location::RequiresRegister());
   return locs;
 }
 
 
 void LoadFieldInstr::EmitNativeCode(FlowGraphCompiler* compiler) {
+  ASSERT(sizeof(classid_t) == 2);
+
   Register instance_reg = locs()->in(0).reg();
   if (IsUnboxedLoad() && compiler->is_optimizing()) {
     XmmRegister result = locs()->out(0).fpu_reg();
     Register temp = locs()->temp(0).reg();
     __ movl(temp, FieldAddress(instance_reg, offset_in_bytes()));
     const intptr_t cid = field()->UnboxedFieldCid();
     switch (cid) {
       case kDoubleCid:
         __ Comment("UnboxedDoubleLoadFieldInstr");
         __ movsd(result, FieldAddress(temp, Double::value_offset()));
@@ skipping 4698 matching lines @@
   __ Drop(1);
   __ popl(result);
 }
 
 
 }  // namespace dart
 
 #undef __
 
 #endif  // defined TARGET_ARCH_IA32