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.code.*;
026import jdk.internal.jvmci.meta.*;
027
028import com.oracle.graal.compiler.common.type.*;
029import com.oracle.graal.graph.*;
030import com.oracle.graal.graph.spi.*;
031import com.oracle.graal.nodeinfo.*;
032import com.oracle.graal.nodes.*;
033import com.oracle.graal.nodes.calc.*;
034import com.oracle.graal.nodes.spi.*;
035
036@NodeInfo
037public final class BitCountNode extends UnaryNode implements LIRLowerable {
038
039    public static final NodeClass<BitCountNode> TYPE = NodeClass.create(BitCountNode.class);
040
041    public BitCountNode(ValueNode value) {
042        super(TYPE, StampFactory.forInteger(Kind.Int, 0, ((PrimitiveStamp) value.stamp()).getBits()), value);
043        assert value.getKind() == Kind.Int || value.getKind() == Kind.Long;
044    }
045
046    @Override
047    public boolean inferStamp() {
048        IntegerStamp valueStamp = (IntegerStamp) getValue().stamp();
049        assert (valueStamp.downMask() & CodeUtil.mask(valueStamp.getBits())) == valueStamp.downMask();
050        assert (valueStamp.upMask() & CodeUtil.mask(valueStamp.getBits())) == valueStamp.upMask();
051        return updateStamp(StampFactory.forInteger(Kind.Int, Long.bitCount(valueStamp.downMask()), Long.bitCount(valueStamp.upMask())));
052    }
053
054    @Override
055    public ValueNode canonical(CanonicalizerTool tool, ValueNode forValue) {
056        if (forValue.isConstant()) {
057            JavaConstant c = forValue.asJavaConstant();
058            return ConstantNode.forInt(forValue.getKind() == Kind.Int ? Integer.bitCount(c.asInt()) : Long.bitCount(c.asLong()));
059        }
060        return this;
061    }
062
063    @Override
064    public void generate(NodeLIRBuilderTool gen) {
065        Value result = gen.getLIRGeneratorTool().emitBitCount(gen.operand(getValue()));
066        gen.setResult(this, result);
067    }
068}