| /* |
| * Copyright 2008 Google Inc. |
| * |
| * Licensed under the Apache License, Version 2.0 (the "License"); you may not |
| * use this file except in compliance with the License. You may obtain a copy of |
| * the License at |
| * |
| * http://www.apache.org/licenses/LICENSE-2.0 |
| * |
| * Unless required by applicable law or agreed to in writing, software |
| * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT |
| * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the |
| * License for the specific language governing permissions and limitations under |
| * the License. |
| */ |
| package com.google.gwt.dev.jjs.impl.gflow.constants; |
| |
| import com.google.gwt.dev.jjs.impl.gflow.Analysis; |
| import com.google.gwt.dev.jjs.impl.gflow.AssumptionMap; |
| import com.google.gwt.dev.jjs.impl.gflow.AssumptionUtil; |
| import com.google.gwt.dev.jjs.impl.gflow.IntegratedAnalysis; |
| import com.google.gwt.dev.jjs.impl.gflow.cfg.Cfg; |
| import com.google.gwt.dev.jjs.impl.gflow.cfg.CfgEdge; |
| import com.google.gwt.dev.jjs.impl.gflow.cfg.CfgNode; |
| import com.google.gwt.dev.jjs.impl.gflow.cfg.CfgTransformer; |
| |
| /** |
| * Constant propagation optimization. |
| * |
| * Detects a situation when variable value is constant and replaces variable |
| * access with constant value. |
| * As of now supports only locals & parameters. |
| */ |
| public class ConstantsAnalysis implements |
| Analysis<CfgNode<?>, CfgEdge, Cfg, ConstantsAssumption>, |
| IntegratedAnalysis<CfgNode<?>, CfgEdge, CfgTransformer, Cfg, ConstantsAssumption> { |
| |
| public ConstantsFlowFunction getFlowFunction() { |
| return new ConstantsFlowFunction(); |
| } |
| |
| public ConstantsIntegratedFlowFunction getIntegratedFlowFunction() { |
| return new ConstantsIntegratedFlowFunction(); |
| } |
| |
| public void setInitialGraphAssumptions(Cfg graph, |
| AssumptionMap<CfgEdge, ConstantsAssumption> assumptionMap) { |
| AssumptionUtil.setAssumptions(graph.getGraphInEdges(), |
| ConstantsAssumption.TOP, assumptionMap); |
| } |
| } |