Delete CPS IR

pkg/compiler/lib/src/cps_ir/eagerly_load_statics.dart

-// Copyright (c) 2015, 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.
-
-library dart2js.cps_ir.eagerly_load_statics;
-
-import '../elements/elements.dart';
-import 'cps_fragment.dart';
-import 'cps_ir_nodes.dart';
-import 'optimizers.dart' show Pass;
-
-/// Replaces [GetLazyStatic] with [GetStatic] when the static field is known
-/// to have been initialized.
-///
-/// Apart from [GetStatic] generating better code, this improves the side-effect
-/// analysis in the [GVN] pass, since [GetStatic] has no effects.
-class EagerlyLoadStatics extends TrampolineRecursiveVisitor implements Pass {
-  String get passName => 'Eagerly load statics';
-
-  Map<FieldElement, Primitive> initializerFor = <FieldElement, Primitive>{};
-
-  final Map<Continuation, Map<FieldElement, Primitive>> initializersAt =
-      <Continuation, Map<FieldElement, Primitive>>{};
-
-  static Map<FieldElement, Primitive> cloneFieldMap(
-      Map<FieldElement, Primitive> map) {
-    return new Map<FieldElement, Primitive>.from(map);
-  }
-
-  void rewrite(FunctionDefinition node) {
-    visit(node.body);
-  }
-
-  Expression traverseLetPrim(LetPrim node) {
-    Expression next = node.body;
-    visit(node.primitive);
-    return next;
-  }
-
-  Expression traverseLetCont(LetCont node) {
-    for (Continuation cont in node.continuations) {
-      initializersAt[cont] = cloneFieldMap(initializerFor);
-      push(cont);
-    }
-    return node.body;
-  }
-
-  Expression traverseLetHandler(LetHandler node) {
-    initializersAt[node.handler] = cloneFieldMap(initializerFor);
-    push(node.handler);
-    return node.body;
-  }
-
-  Expression traverseContinuation(Continuation cont) {
-    initializerFor = initializersAt[cont];
-    return cont.body;
-  }
-
-  void visitGetLazyStatic(GetLazyStatic node) {
-    Primitive initializer = initializerFor[node.element];
-    if (initializer is GetLazyStatic && initializer.isFinal) {
-      // No reason to create a GetStatic when the field is final.
-      node.replaceWithFragment(new CpsFragment(), initializer);
-    } else if (initializer != null) {
-      GetStatic newNode = new GetStatic.witnessed(node.element, initializer,
-          sourceInformation: node.sourceInformation)..type = node.type;
-      node.replaceWith(newNode);
-    } else {
-      initializerFor[node.element] = node;
-    }
-  }
-
-  void visitSetStatic(SetStatic node) {
-    initializerFor.putIfAbsent(node.element, () => node);
-  }
-}