Implement optional parameter handling in ARM vm.

runtime/vm/assembler_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/simulator.h"
 #include "vm/runtime_entry.h"
@@ skipping 1244 matching lines @@
         movt(rd, value_high);
       }
       add(rd, PP, ShifterOperand(LR));
     }
     ldr(rd, Address(rd, offset_lo));
   }
 }
 
 
 void Assembler::LoadObject(Register rd, const Object& object) {
+  // Since objects in the VM heap are never relocated, test instead
+  // if (object.IsSmi() || object.InVMHeap()) {
+  // and modify the decoding code in CallPattern to understand movt, movw.
   if (object.IsNull() ||
       object.IsSmi() ||
       (object.raw() == Bool::True().raw()) ||
       (object.raw() == Bool::False().raw())) {
     // This object is never relocated; do not use object pool.
     LoadImmediate(rd, reinterpret_cast<int32_t>(object.raw()));
     return;
   }
   const int32_t offset =
       Array::data_offset() + 4*AddObject(object) - kHeapObjectTag;
   LoadWordFromPoolOffset(rd, offset);
 }
 
 
 void Assembler::PushObject(const Object& object) {
   LoadObject(IP, object);
   Push(IP);
 }
 
 
+void Assembler::CompareObject(Register rn, const Object& object) {
+  ASSERT(rn != IP);
+  LoadObject(IP, object);
+  cmp(rn, ShifterOperand(IP));
+}
+
+
 void Assembler::Bind(Label* label) {
   ASSERT(!label->IsBound());
   int bound_pc = buffer_.Size();
   while (label->IsLinked()) {
     int32_t position = label->Position();
     int32_t next = buffer_.Load<int32_t>(position);
     int32_t encoded = Assembler::EncodeBranchOffset(bound_pc - position, next);
     buffer_.Store<int32_t>(position, encoded);
     label->position_ = Assembler::DecodeBranchOffset(next);
   }
@@ skipping 617 matching lines @@
 }
 
 
 int Assembler::DecodeBranchOffset(int32_t inst) {
   // Sign-extend, left-shift by 2, then add 8.
   return ((((inst & kBranchOffsetMask) << 8) >> 6) + 8);
 }
 
 
 int32_t Assembler::AddObject(const Object& obj) {
+  ASSERT(obj.IsNotTemporaryScopedHandle());
+  ASSERT(obj.IsOld());
   if (object_pool_.IsNull()) {
     // The object pool cannot be used in the vm isolate.
     ASSERT(Isolate::Current() != Dart::vm_isolate());
     object_pool_ = GrowableObjectArray::New();
   }
   for (int i = 0; i < object_pool_.Length(); i++) {
     if (object_pool_.At(i) == obj.raw()) {
       return i;
     }
   }
@@ skipping 15 matching lines @@
   // Do not reuse an existing entry, since each reference may be patched
   // independently.
   object_pool_.Add(smi);
   return object_pool_.Length() - 1;
 }
 
 }  // namespace dart
 
 #endif  // defined TARGET_ARCH_ARM