001/*
002 * Copyright (c) 2013, Oracle and/or its affiliates. All rights reserved.
003 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
004 *
005 * This code is free software; you can redistribute it and/or modify it
006 * under the terms of the GNU General Public License version 2 only, as
007 * published by the Free Software Foundation.
008 *
009 * This code is distributed in the hope that it will be useful, but WITHOUT
010 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
011 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
012 * version 2 for more details (a copy is included in the LICENSE file that
013 * accompanied this code).
014 *
015 * You should have received a copy of the GNU General Public License version
016 * 2 along with this work; if not, write to the Free Software Foundation,
017 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
018 *
019 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
020 * or visit www.oracle.com if you need additional information or have any
021 * questions.
022 */
023package com.oracle.graal.phases.common;
024
025import com.oracle.graal.compiler.common.type.*;
026import com.oracle.graal.nodes.*;
027import com.oracle.graal.phases.*;
028
029/**
030 * Modifies the stamp of all object {@linkplain ParameterNode parameters} in a graph to denote they
031 * are non-null. This can be used for graphs where the caller null checks all arguments.
032 */
033public class NonNullParametersPhase extends Phase {
034
035    @Override
036    protected void run(StructuredGraph graph) {
037        Stamp nonNull = StampFactory.objectNonNull();
038        for (ParameterNode param : graph.getNodes(ParameterNode.TYPE)) {
039            if (param.stamp() instanceof ObjectStamp) {
040                ObjectStamp paramStamp = (ObjectStamp) param.stamp();
041                param.setStamp(paramStamp.join(nonNull));
042            }
043        }
044    }
045}