| /* |
| * 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.copy; |
| |
| import com.google.gwt.dev.jjs.ast.JLocal; |
| import com.google.gwt.dev.jjs.ast.JParameter; |
| import com.google.gwt.dev.jjs.ast.JVariable; |
| import com.google.gwt.dev.jjs.ast.JVariableRef; |
| 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.FlowFunction; |
| 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.CfgReadWriteNode; |
| import com.google.gwt.dev.jjs.impl.gflow.cfg.CfgVisitor; |
| import com.google.gwt.dev.jjs.impl.gflow.cfg.CfgWriteNode; |
| import com.google.gwt.dev.jjs.impl.gflow.copy.CopyAssumption.Updater; |
| |
| /** |
| * Flow function for CopyAnalysis. |
| */ |
| public class CopyFlowFunction implements |
| FlowFunction<CfgNode<?>, CfgEdge, Cfg, CopyAssumption> { |
| public void interpret(CfgNode<?> node, |
| Cfg g, AssumptionMap<CfgEdge, CopyAssumption> assumptionMap) { |
| CopyAssumption in = AssumptionUtil.join(g.getInEdges(node), assumptionMap); |
| final Updater result = new Updater(in); |
| |
| node.accept(new CfgVisitor() { |
| @Override |
| public void visitReadWriteNode(CfgReadWriteNode node) { |
| JVariable targetVariable = node.getTargetVariable(); |
| if (isSupportedVar(targetVariable)) { |
| result.kill(targetVariable); |
| } |
| } |
| |
| @Override |
| public void visitWriteNode(CfgWriteNode node) { |
| JVariable targetVariable = node.getTargetVariable(); |
| if (!isSupportedVar(targetVariable)) { |
| return; |
| } |
| |
| if (!(node.getValue() instanceof JVariableRef)) { |
| result.kill(targetVariable); |
| return; |
| } |
| |
| JVariable original = ((JVariableRef) node.getValue()).getTarget(); |
| original = result.getMostOriginal(original); |
| |
| if (original != targetVariable) { |
| result.kill(targetVariable); |
| if (isSupportedVar(original)) { |
| result.addCopy(original, targetVariable); |
| } |
| } else { |
| // We don't have to kill any assumptions after i = i assignment. |
| } |
| } |
| |
| private boolean isSupportedVar(JVariable targetVariable) { |
| return targetVariable instanceof JParameter || |
| targetVariable instanceof JLocal; |
| } |
| }); |
| |
| AssumptionUtil.setAssumptions(g.getOutEdges(node), result.unwrap(), assumptionMap); |
| } |
| } |