Cache initial (empty) ic_data arrays so that they are not repeatedly allocated. Factor out descript…

runtime/vm/snapshot.cc

 // Copyright (c) 2012, 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/snapshot.h"
 
 #include "platform/assert.h"
 #include "vm/bootstrap.h"
 #include "vm/class_finalizer.h"
 #include "vm/dart.h"
@@ skipping 1315 matching lines @@
     return isolate()->class_table()->At(class_id);  // get singleton class.
   }
 
   // Check if it is a singleton Argument descriptor object.
   for (intptr_t i = 0; i < ArgumentsDescriptor::kCachedDescriptorCount; i++) {
     if (object_id == (kCachedArgumentsDescriptor0 + i)) {
       return ArgumentsDescriptor::cached_args_descriptors_[i];
     }
   }
 
+  // Check if it is a singleton ICData array object.
+  for (intptr_t i = 0; i < ICData::kCachedICDataArrayCount; i++) {
+    if (object_id == (kCachedICDataArray0 + i)) {
+      return ICData::cached_icdata_arrays_[i];
+    }
+  }
+
   ASSERT(Symbols::IsVMSymbolId(object_id));
   return Symbols::GetVMSymbol(object_id);  // return VM symbol.
 }
 
 
 RawObject* SnapshotReader::ReadIndexedObject(intptr_t object_id,
                                              intptr_t patch_object_id,
                                              intptr_t patch_offset) {
   intptr_t class_id = ClassIdFromObjectId(object_id);
   if (IsObjectStoreClassId(class_id)) {
@@ skipping 322 matching lines @@
   }
 
   // Check if it is a singleton Argument descriptor object.
   for (intptr_t i = 0; i < ArgumentsDescriptor::kCachedDescriptorCount; i++) {
     if (rawobj == ArgumentsDescriptor::cached_args_descriptors_[i]) {
       WriteVMIsolateObject(kCachedArgumentsDescriptor0 + i);
       return true;
     }
   }
 
+  // Check if it is a singleton ICData array object.
+  for (intptr_t i = 0; i < ICData::kCachedICDataArrayCount; i++) {
+    if (rawobj == ICData::cached_icdata_arrays_[i]) {
+      WriteVMIsolateObject(kCachedICDataArray0 + i);
+      return true;
+    }
+  }
+
   if (kind() == Snapshot::kFull) {
     // Check it is a predefined symbol in the VM isolate.
     id = Symbols::LookupVMSymbol(rawobj);
     if (id != kInvalidIndex) {
       WriteVMIsolateObject(id);
       return true;
     }
 
     // Check if it is an object from the vm isolate snapshot object table.
     id = FindVmSnapshotObject(rawobj);
@@ skipping 867 matching lines @@
   if (setjmp(*jump.Set()) == 0) {
     NoSafepointScope no_safepoint;
     WriteObject(obj.raw());
   } else {
     ThrowException(exception_type(), exception_msg());
   }
 }
 
 
 }  // namespace dart