Improve constant pool implementation in the assembler.

runtime/vm/assembler_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"  // NOLINT
 #if defined(TARGET_ARCH_X64)
 
 #include "vm/assembler.h"
 #include "vm/cpu.h"
 #include "vm/heap.h"
@@ skipping 19 matching lines @@
   // Far branching mode is only needed and implemented for MIPS and ARM.
   ASSERT(!use_far_branches);
   Isolate* isolate = Isolate::Current();
   if (isolate != Dart::vm_isolate()) {
     object_pool_ = GrowableObjectArray::New(Heap::kOld);
 
     // These objects and labels need to be accessible through every pool-pointer
     // at the same index.
     object_pool_.Add(Object::null_object(), Heap::kOld);
     patchable_pool_entries_.Add(kNotPatchable);
-    // Not adding Object::null() to the index table. It is at index 0 in the
-    // object pool, but the HashMap uses 0 to indicate not found.
+    object_pool_index_table_.Insert(ObjIndexPair(&Object::null_object(), 0));
 
     object_pool_.Add(Bool::True(), Heap::kOld);
     patchable_pool_entries_.Add(kNotPatchable);
-    object_pool_index_table_.Insert(ObjIndexPair(Bool::True().raw(), 1));
+    object_pool_index_table_.Insert(ObjIndexPair(&Bool::True(), 1));
 
     object_pool_.Add(Bool::False(), Heap::kOld);
     patchable_pool_entries_.Add(kNotPatchable);
-    object_pool_index_table_.Insert(ObjIndexPair(Bool::False().raw(), 2));
+    object_pool_index_table_.Insert(ObjIndexPair(&Bool::False(), 2));
 
     const Smi& vacant = Smi::Handle(Smi::New(0xfa >> kSmiTagShift));
 
     StubCode* stub_code = isolate->stub_code();
     if (stub_code->UpdateStoreBuffer_entry() != NULL) {
       FindExternalLabel(&stub_code->UpdateStoreBufferLabel(), kNotPatchable);
     } else {
       object_pool_.Add(vacant, Heap::kOld);
       patchable_pool_entries_.Add(kNotPatchable);
     }
@@ skipping 2705 matching lines @@
 
 
 intptr_t Assembler::FindObject(const Object& obj, Patchability patchable) {
   // The object pool cannot be used in the vm isolate.
   ASSERT(Isolate::Current() != Dart::vm_isolate());
   ASSERT(!object_pool_.IsNull());
 
   // If the object is not patchable, check if we've already got it in the
   // object pool.
   if (patchable == kNotPatchable) {
-    // Special case for Object::null(), which is always at object_pool_ index 0
-    // because Lookup() below returns 0 when the object is not mapped in the
-    // table.
-    if (obj.raw() == Object::null()) {
-      return 0;
-    }
-
-    intptr_t idx = object_pool_index_table_.Lookup(obj.raw());
-    if (idx != 0) {
+    intptr_t idx = object_pool_index_table_.Lookup(&obj);
+    if (idx != ObjIndexPair::NoValue()) {
       ASSERT(patchable_pool_entries_[idx] == kNotPatchable);
       return idx;
     }
   }
 
   object_pool_.Add(obj, Heap::kOld);
   patchable_pool_entries_.Add(patchable);
   if (patchable == kNotPatchable) {
     // The object isn't patchable. Record the index for fast lookup.
     object_pool_index_table_.Insert(
-        ObjIndexPair(obj.raw(), object_pool_.Length() - 1));
+        ObjIndexPair(&obj, object_pool_.Length() - 1));
   }
   return object_pool_.Length() - 1;
 }
 
 
 intptr_t Assembler::FindExternalLabel(const ExternalLabel* label,
                                       Patchability patchable) {
   // The object pool cannot be used in the vm isolate.
   ASSERT(Isolate::Current() != Dart::vm_isolate());
   ASSERT(!object_pool_.IsNull());
@@ skipping 1197 matching lines @@
 
 
 const char* Assembler::FpuRegisterName(FpuRegister reg) {
   ASSERT((0 <= reg) && (reg < kNumberOfXmmRegisters));
   return xmm_reg_names[reg];
 }
 
 }  // namespace dart
 
 #endif  // defined TARGET_ARCH_X64