Improve constant pool implementation in the assembler.

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"  // NOLINT
 #if defined(TARGET_ARCH_ARM)
 
 #include "vm/assembler.h"
 #include "vm/cpu.h"
 #include "vm/longjump.h"
@@ skipping 3488 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;
 }
 
 
 int32_t Assembler::AddExternalLabel(const ExternalLabel* label) {
   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);
   }
@@ skipping 96 matching lines @@
 
 
 const char* Assembler::FpuRegisterName(FpuRegister reg) {
   ASSERT((0 <= reg) && (reg < kNumberOfFpuRegisters));
   return fpu_reg_names[reg];
 }
 
 }  // namespace dart
 
 #endif  // defined TARGET_ARCH_ARM