001/*
002 * Copyright (c) 2012, 2014, 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.replacements.nodes;
024
025import jdk.internal.jvmci.meta.*;
026
027import com.oracle.graal.compiler.common.type.*;
028import com.oracle.graal.graph.*;
029import com.oracle.graal.nodeinfo.*;
030import com.oracle.graal.nodes.*;
031import com.oracle.graal.nodes.extended.*;
032import com.oracle.graal.nodes.spi.*;
033
034/**
035 * A special purpose store node that differs from {@link UnsafeStoreNode} in that it is not a
036 * {@link StateSplit} and takes a computed address instead of an object.
037 */
038@NodeInfo
039public final class DirectReadNode extends FixedWithNextNode implements LIRLowerable {
040
041    public static final NodeClass<DirectReadNode> TYPE = NodeClass.create(DirectReadNode.class);
042    @Input protected ValueNode address;
043    protected final Kind readKind;
044
045    public DirectReadNode(ValueNode address, Kind readKind) {
046        super(TYPE, StampFactory.forKind(readKind.getStackKind()));
047        this.address = address;
048        this.readKind = readKind;
049    }
050
051    protected ValueNode getAddress() {
052        return address;
053    }
054
055    /**
056     * If we are sub int sizes, we try to sign/zero extend the value to at least int as it is done
057     * in the {@link com.oracle.graal.replacements.DefaultJavaLoweringProvider#implicitLoadConvert}
058     * and {@link com.oracle.graal.replacements.DefaultJavaLoweringProvider#createUnsafeRead}.
059     *
060     * @see com.oracle.graal.replacements.DefaultJavaLoweringProvider#implicitLoadConvert
061     * @see com.oracle.graal.replacements.DefaultJavaLoweringProvider#createUnsafeRead
062     */
063    @Override
064    public void generate(NodeLIRBuilderTool gen) {
065        LIRKind kind = gen.getLIRGeneratorTool().target().getLIRKind(readKind);
066        Value loaded = gen.getLIRGeneratorTool().emitLoad(kind, gen.operand(address), null);
067        switch ((Kind) kind.getPlatformKind()) {
068            case Byte:
069                loaded = gen.getLIRGeneratorTool().emitSignExtend(loaded, 8, 32);
070                break;
071            case Short:
072                loaded = gen.getLIRGeneratorTool().emitSignExtend(loaded, 16, 32);
073                break;
074            case Boolean:
075                loaded = gen.getLIRGeneratorTool().emitZeroExtend(loaded, 8, 32);
076                break;
077            case Char:
078                loaded = gen.getLIRGeneratorTool().emitZeroExtend(loaded, 16, 32);
079                break;
080        }
081        gen.setResult(this, loaded);
082    }
083}