Change heuristic to determine which fields contain modifieable double boxes: do it if field was ini…

runtime/vm/parser.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/parser.h"
 
 #include "lib/invocation_mirror.h"
 #include "platform/utils.h"
 #include "vm/ast_transformer.h"
 #include "vm/bootstrap.h"
@@ skipping 3954 matching lines @@
       // For instance fields, the expression is parsed when a constructor
       // is compiled.
       // For static fields with very simple initializer expressions
       // (e.g. a literal number or string), we optimize away the
       // kImplicitStaticFinalGetter and initialize the field here.
       // However, the class finalizer will check the value type for
       // assignability once the declared field type can be resolved. If the
       // value is not assignable (assuming checked mode and disregarding actual
       // mode), the field value is reset and a kImplicitStaticFinalGetter is
       // created at finalization time.
-      if (LookaheadToken(1) == Token::kSEMICOLON) {
+      if ((LookaheadToken(1) == Token::kSEMICOLON) ||
+          (LookaheadToken(1) == Token::kCOMMA)) {
         has_simple_literal = IsSimpleLiteral(*field->type, &init_value);
       }
       SkipExpr();
     } else {
       // Static const and static final fields must have an initializer.
       // Static const fields are implicitly final.
       if (field->has_static && field->has_final) {
         ReportError(field->name_pos,
                     "static %s field '%s' must have an initializer expression",
                     field->has_const ? "const" : "final",
@@ skipping 17 matching lines @@
     field->field_ = &class_field;
     if (field->metadata_pos >= 0) {
       library_.AddFieldMetadata(class_field, field->metadata_pos);
     }
 
     // Start tracking types for fields with simple initializers in their
     // definition. This avoids some of the overhead to track this at runtime
     // and rules out many fields from being unnecessary unboxing candidates.
     if (!field->has_static && has_initializer && has_simple_literal) {
       class_field.RecordStore(init_value);
+      if (!init_value.IsNull() && init_value.IsDouble()) {
+        class_field.set_is_double_initialized(true);
+      }
     }
 
     // For static final fields (this includes static const fields), set value to
     // "uninitialized" and create a kImplicitStaticFinalGetter getter method.
     if (field->has_static && has_initializer) {
       class_field.set_value(init_value);
       if (!has_simple_literal) {
         String& getter_name =
             String::Handle(Z, Field::GetterSymbol(*field->name));
         getter = Function::New(getter_name,
@@ skipping 10034 matching lines @@
 void Parser::SkipQualIdent() {
   ASSERT(IsIdentifier());
   ConsumeToken();
   if (CurrentToken() == Token::kPERIOD) {
     ConsumeToken();  // Consume the kPERIOD token.
     ExpectIdentifier("identifier expected after '.'");
   }
 }
 
 }  // namespace dart