Recognize const/fixed/growable arrays in simple types inferrer.

sdk/lib/_internal/compiler/implementation/ssa/builder.dart

 // 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.
 
 part of ssa;
 
 /**
  * A special element for the extra parameter taken by intercepted
  * methods. We need to override [Element.computeType] because our
  * optimizers may look at its declared type.
@@ skipping 3252 matching lines @@
    *
    * Invariant: [type] must not be malformed in checked mode.
    */
   visitNewSend(Send node, InterfaceType type) {
     assert(invariant(node,
                      !compiler.enableTypeAssertions || !type.isMalformed,
                      message: '$type is malformed in checked mode'));
     bool isListConstructor = false;
     computeType(element) {
       Element originalElement = elements[node];
-      if (identical(originalElement.getEnclosingClass(), compiler.listClass)) {
+      if (Elements.isFixedListConstructorCall(
+              originalElement, node, compiler)) {
         isListConstructor = true;
-        if (node.arguments.isEmpty) {
-          return HType.EXTENDABLE_ARRAY;
-        } else {
-          return HType.MUTABLE_ARRAY;

[kasperl, 2013/03/11 08:40:57]

Was this just pessimistic before?

[ngeoffray, 2013/03/11 08:59:57]

Yes it was. But the optimizers were putting it back to FIXED_LENGTH. I'm not
sure when and how we got that weird state. Frequent changes on the List class
lately may have created this situation.

-        }
+        return HType.FIXED_ARRAY;
+      } else if (Elements.isGrowableListConstructorCall(
+                    originalElement, node, compiler)) {
+        isListConstructor = true;
+        return HType.EXTENDABLE_ARRAY;
       } else if (element.isGenerativeConstructor()) {
         ClassElement cls = element.getEnclosingClass();
         return new HType.nonNullExact(cls.thisType, compiler);
       } else {
         return HType.UNKNOWN;
       }
     }
 
     Element constructor = elements[node];
     Selector selector = elements.getSelector(node);
@@ skipping 1806 matching lines @@
           new HSubGraphBlockInformation(elseBranch.graph));
 
     HBasicBlock conditionStartBlock = conditionBranch.block;
     conditionStartBlock.setBlockFlow(info, joinBlock);
     SubGraph conditionGraph = conditionBranch.graph;
     HIf branch = conditionGraph.end.last;
     assert(branch is HIf);
     branch.blockInformation = conditionStartBlock.blockFlow;
   }
 }