- Remove redundant initialization in Array::New

vm/object.cc

 // Copyright (c) 2011, 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/object.h"
 
 #include "vm/assembler.h"
 #include "vm/assert.h"
 #include "vm/bigint_operations.h"
 #include "vm/bootstrap.h"
@@ skipping 5260 matching lines @@
     result ^= raw;
     uword addr = reinterpret_cast<uword>(result.raw_ptr());
     // Initialize fields.
     intptr_t offset = sizeof(RawObject);
     // Initialize all native fields to NULL.
     for (intptr_t i = 0; i < cls.num_native_fields(); i++) {
       *reinterpret_cast<uword*>(addr + offset) = 0;
       offset += kWordSize;
     }
     // Initialize all dart fields to null.
     while (offset < instance_size) {

[Ivan Posva, 2012/01/06 21:40:05]

This could be dropped as well.

[siva, 2012/01/07 00:01:02]

Good point. Done.

On 2012/01/06 21:40:05, Ivan Posva wrote:

       *reinterpret_cast<RawObject**>(addr + offset) = Object::null();
       offset += kWordSize;
     }
   }
   return result.raw();
 }
 
 
 bool Instance::IsValidFieldOffset(int offset) const {
   const Class& cls = Class::Handle(clazz());
@@ skipping 1813 matching lines @@
     cls = isolate->object_store()->array_class();
   }
   Array& result = Array::Handle();
   {
     RawObject* raw = Object::Allocate(cls,
                                       Array::InstanceSize(len),
                                       space);
     NoGCScope no_gc;
     result ^= raw;
     result.SetLength(len);
-    for (intptr_t i = 0; i < len; i++) {
-      *result.ObjectAddr(i) = Object::null();
-    }
+    // Object::Allocate has already initialized the allocated area.

[Ivan Posva, 2012/01/06 21:40:05]

Comment can be dropped, no?

[siva, 2012/01/07 00:01:02]

Done.

   }
   return result.raw();
 }
 
 
 void Array::MakeImmutable() const {
   Isolate* isolate = Isolate::Current();
   raw()->ptr()->class_ = isolate->object_store()->immutable_array_class();
 }
 
@@ skipping 376 matching lines @@
   const String& str = String::Handle(pattern());
   const char* format = "JSRegExp: pattern=%s flags=%s";
   intptr_t len = OS::SNPrint(NULL, 0, format, str.ToCString(), Flags());
   char* chars = reinterpret_cast<char*>(
       Isolate::Current()->current_zone()->Allocate(len + 1));
   OS::SNPrint(chars, (len + 1), format, str.ToCString(), Flags());
   return chars;
 }
 
 }  // namespace dart