/*
* Copyright (c) 2014, 2016, Oracle and/or its affiliates. All rights reserved.
* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
*
* This code is free software; you can redistribute it and/or modify it
* under the terms of the GNU General Public License version 2 only, as
* published by the Free Software Foundation.
*
* This code is distributed in the hope that it will be useful, but WITHOUT
* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
* version 2 for more details (a copy is included in the LICENSE file that
* accompanied this code).
*
* You should have received a copy of the GNU General Public License version
* 2 along with this work; if not, write to the Free Software Foundation,
* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
*
* Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
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*/
package org.graalvm.compiler.nodes;
import static org.graalvm.compiler.core.common.GraalOptions.GeneratePIC;
import static org.graalvm.compiler.nodeinfo.NodeCycles.CYCLES_2;
import static org.graalvm.compiler.nodeinfo.NodeSize.SIZE_2;
import org.graalvm.compiler.core.common.CompressEncoding;
import org.graalvm.compiler.core.common.type.AbstractObjectStamp;
import org.graalvm.compiler.core.common.type.Stamp;
import org.graalvm.compiler.debug.GraalError;
import org.graalvm.compiler.graph.NodeClass;
import org.graalvm.compiler.graph.spi.CanonicalizerTool;
import org.graalvm.compiler.lir.gen.LIRGeneratorTool;
import org.graalvm.compiler.nodeinfo.NodeInfo;
import org.graalvm.compiler.nodes.calc.ConvertNode;
import org.graalvm.compiler.nodes.calc.UnaryNode;
import org.graalvm.compiler.nodes.spi.LIRLowerable;
import org.graalvm.compiler.nodes.spi.NodeLIRBuilderTool;
import org.graalvm.compiler.nodes.type.StampTool;
import jdk.vm.ci.meta.Constant;
import jdk.vm.ci.meta.ConstantReflectionProvider;
import jdk.vm.ci.meta.Value;
/**
* Compress or uncompress an oop or metaspace pointer.
*/
@NodeInfo(nameTemplate = "{p#op/s}", cycles = CYCLES_2, size = SIZE_2)
public abstract class CompressionNode extends UnaryNode implements ConvertNode, LIRLowerable {
public static final NodeClass<CompressionNode> TYPE = NodeClass.create(CompressionNode.class);
public enum CompressionOp {
Compress,
Uncompress
}
protected final CompressionOp op;
protected final CompressEncoding encoding;
public CompressionNode(NodeClass<? extends UnaryNode> c, CompressionOp op, ValueNode input, Stamp stamp, CompressEncoding encoding) {
super(c, stamp, input);
this.op = op;
this.encoding = encoding;
}
@Override
public Stamp foldStamp(Stamp newStamp) {
assert newStamp.isCompatible(getValue().stamp());
return mkStamp(newStamp);
}
protected abstract Constant compress(Constant c);
protected abstract Constant uncompress(Constant c);
@Override
public Constant convert(Constant c, ConstantReflectionProvider constantReflection) {
switch (op) {
case Compress:
return compress(c);
case Uncompress:
return uncompress(c);
default:
throw GraalError.shouldNotReachHere();
}
}
@Override
public Constant reverse(Constant c, ConstantReflectionProvider constantReflection) {
switch (op) {
case Compress:
return uncompress(c);
case Uncompress:
return compress(c);
default:
throw GraalError.shouldNotReachHere();
}
}
@Override
public boolean isLossless() {
return true;
}
protected abstract Stamp mkStamp(Stamp input);
public CompressionOp getOp() {
return op;
}
public CompressEncoding getEncoding() {
return encoding;
}
@Override
public ValueNode canonical(CanonicalizerTool tool, ValueNode forValue) {
if (forValue.isConstant()) {
if (GeneratePIC.getValue(tool.getOptions())) {
// We always want uncompressed constants
return this;
}
int stableDimension = ((ConstantNode) forValue).getStableDimension();
boolean isDefaultStable = ((ConstantNode) forValue).isDefaultStable();
return ConstantNode.forConstant(stamp(), convert(forValue.asConstant(), tool.getConstantReflection()), stableDimension, isDefaultStable, tool.getMetaAccess());
} else if (forValue instanceof CompressionNode) {
CompressionNode other = (CompressionNode) forValue;
if (op != other.op && encoding.equals(other.encoding)) {
return other.getValue();
}
}
return this;
}
@Override
public void generate(NodeLIRBuilderTool gen) {
LIRGeneratorTool hsGen = gen.getLIRGeneratorTool();
boolean nonNull;
if (getValue().stamp() instanceof AbstractObjectStamp) {
nonNull = StampTool.isPointerNonNull(getValue().stamp());
} else {
// metaspace pointers are never null
nonNull = true;
}
Value result;
switch (op) {
case Compress:
result = hsGen.emitCompress(gen.operand(getValue()), encoding, nonNull);
break;
case Uncompress:
result = hsGen.emitUncompress(gen.operand(getValue()), encoding, nonNull);
break;
default:
throw GraalError.shouldNotReachHere();
}
gen.setResult(this, result);
}
@Override
public boolean mayNullCheckSkipConversion() {
return true;
}
}