dart2js cps: Share interceptors by default and propagate to use later.

pkg/compiler/lib/src/js_backend/codegen/task.dart

 // Copyright (c) 2014, 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.
 
 /// Generate code using the cps-based IR pipeline.
 library code_generator_task;
 
 import 'glue.dart';
 import 'codegen.dart';
 import 'unsugar.dart';
@@ skipping 100 matching lines @@
 
     cps.FunctionDefinition cpsNode = irBuilderTask.buildNode(element);
     if (cpsNode == null) {
       if (irBuilderTask.bailoutMessage == null) {
         giveUp('unable to build cps definition of $element');
       } else {
         giveUp(irBuilderTask.bailoutMessage);
       }
     }
     traceGraph("IR Builder", cpsNode);
+    // Eliminating redundant phis before the unsugaring pass will make it
+    // insert fewer getInterceptor calls.
+    new RedundantPhiEliminator().rewrite(cpsNode);
+    traceGraph("Redundant phi elimination", cpsNode);
     new UnsugarVisitor(glue).rewrite(cpsNode);
     traceGraph("Unsugaring", cpsNode);
     return cpsNode;
   }
 
   static const Pattern PRINT_TYPED_IR_FILTER = null;
 
   String formatTypeMask(TypeMask type) {
     if (type is UnionTypeMask) {
       return '[${type.disjointMasks.map(formatTypeMask).join(', ')}]';
@@ skipping 31 matching lines @@
   }
 
   cps.FunctionDefinition optimizeCpsIR(cps.FunctionDefinition cpsNode) {
     // Transformations on the CPS IR.
     void applyCpsPass(cps_opt.Pass pass) {
       pass.rewrite(cpsNode);
       traceGraph(pass.passName, cpsNode);
       assert(checkCpsIntegrity(cpsNode));
     }
 
-    applyCpsPass(new RedundantPhiEliminator());
     TypePropagator typePropagator = new TypePropagator(compiler);
     applyCpsPass(typePropagator);
     dumpTypedIR(cpsNode, typePropagator);
     applyCpsPass(new ShrinkingReducer());
     applyCpsPass(new MutableVariableEliminator());
     applyCpsPass(new RedundantJoinEliminator());
     applyCpsPass(new RedundantPhiEliminator());
     applyCpsPass(new ShrinkingReducer());
+    applyCpsPass(new LetSinker());
 
     return cpsNode;
   }
 
   tree_ir.FunctionDefinition compileToTreeIR(cps.FunctionDefinition cpsNode) {
     tree_builder.Builder builder = new tree_builder.Builder(
         compiler.internalError);
     tree_ir.FunctionDefinition treeNode = builder.buildFunction(cpsNode);
     assert(treeNode != null);
     traceGraph('Tree builder', treeNode);
@@ skipping 32 matching lines @@
     // TODO(sigurdm): Make a better list of tasks.
     return <CompilerTask>[irBuilderTask]..addAll(fallbackCompiler.tasks);
   }
 
   js.Node attachPosition(js.Node node, AstElement element) {
     return node.withSourceInformation(
         sourceInformationFactory.createBuilderForContext(element)
             .buildDeclaration(element));
   }
 }