Improve constant pool implementation in the assembler.

runtime/vm/assembler_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"  // NOLINT
 #if defined(TARGET_ARCH_MIPS)
 
 #include "vm/assembler.h"
 #include "vm/longjump.h"
 #include "vm/runtime_entry.h"
@@ skipping 468 matching lines @@
 
 
 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(Heap::kOld);
   }
-  for (intptr_t i = 0; i < object_pool_.Length(); i++) {
-    if (object_pool_.At(i) == obj.raw()) {
-      return i;
-    }
+
+  intptr_t index = object_pool_index_table_.Lookup(&obj);
+  if (index != ObjIndexPair::kNoIndex) {
+    return index;
   }
+
   object_pool_.Add(obj, Heap::kOld);
+  object_pool_index_table_.Insert(
+      ObjIndexPair(&obj, object_pool_.Length() - 1));
   return object_pool_.Length() - 1;
 }
 
 
 void Assembler::PushObject(const Object& object) {
   ASSERT(!in_delay_slot_);
   LoadObject(TMP, object);
   Push(TMP);
 }
 
@@ skipping 754 matching lines @@
     Emit(reinterpret_cast<int32_t>(message));
     Bind(&msg);
     break_(Instr::kSimulatorMessageCode);
   }
 #endif
 }
 
 }  // namespace dart
 
 #endif  // defined TARGET_ARCH_MIPS