1 /*
   2  * Copyright (c) 2012, 2015, Oracle and/or its affiliates. All rights reserved.
   3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
   4  *
   5  * This code is free software; you can redistribute it and/or modify it
   6  * under the terms of the GNU General Public License version 2 only, as
   7  * published by the Free Software Foundation.
   8  *
   9  * This code is distributed in the hope that it will be useful, but WITHOUT
  10  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  11  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  12  * version 2 for more details (a copy is included in the LICENSE file that
  13  * accompanied this code).
  14  *
  15  * You should have received a copy of the GNU General Public License version
  16  * 2 along with this work; if not, write to the Free Software Foundation,
  17  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
  18  *
  19  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
  20  * or visit www.oracle.com if you need additional information or have any
  21  * questions.
  22  */
  23 package org.graalvm.compiler.replacements.nodes;
  24 
  25 import static org.graalvm.compiler.nodeinfo.NodeCycles.CYCLES_3;
  26 import static org.graalvm.compiler.nodeinfo.NodeSize.SIZE_1;
  27 
  28 import org.graalvm.compiler.core.common.type.IntegerStamp;
  29 import org.graalvm.compiler.core.common.type.Stamp;
  30 import org.graalvm.compiler.core.common.type.StampFactory;
  31 import org.graalvm.compiler.graph.NodeClass;
  32 import org.graalvm.compiler.graph.spi.CanonicalizerTool;
  33 import org.graalvm.compiler.lir.gen.ArithmeticLIRGeneratorTool;
  34 import org.graalvm.compiler.nodeinfo.NodeInfo;
  35 import org.graalvm.compiler.nodes.ConstantNode;
  36 import org.graalvm.compiler.nodes.ValueNode;
  37 import org.graalvm.compiler.nodes.calc.UnaryNode;
  38 import org.graalvm.compiler.nodes.spi.ArithmeticLIRLowerable;
  39 import org.graalvm.compiler.nodes.spi.NodeLIRBuilderTool;
  40 
  41 import jdk.vm.ci.code.CodeUtil;
  42 import jdk.vm.ci.meta.JavaConstant;
  43 import jdk.vm.ci.meta.JavaKind;
  44 
  45 @NodeInfo(cycles = CYCLES_3, size = SIZE_1)
  46 public final class BitCountNode extends UnaryNode implements ArithmeticLIRLowerable {
  47 
  48     public static final NodeClass<BitCountNode> TYPE = NodeClass.create(BitCountNode.class);
  49 
  50     public BitCountNode(ValueNode value) {
  51         super(TYPE, computeStamp(value.stamp(), value), value);
  52         assert value.getStackKind() == JavaKind.Int || value.getStackKind() == JavaKind.Long;
  53     }
  54 
  55     @Override
  56     public Stamp foldStamp(Stamp newStamp) {
  57         ValueNode theValue = getValue();
  58         return computeStamp(newStamp, theValue);
  59     }
  60 
  61     static Stamp computeStamp(Stamp newStamp, ValueNode theValue) {
  62         assert newStamp.isCompatible(theValue.stamp());
  63         IntegerStamp valueStamp = (IntegerStamp) newStamp;
  64         assert (valueStamp.downMask() & CodeUtil.mask(valueStamp.getBits())) == valueStamp.downMask();
  65         assert (valueStamp.upMask() & CodeUtil.mask(valueStamp.getBits())) == valueStamp.upMask();
  66         return StampFactory.forInteger(JavaKind.Int, Long.bitCount(valueStamp.downMask()), Long.bitCount(valueStamp.upMask()));
  67     }
  68 
  69     @Override
  70     public ValueNode canonical(CanonicalizerTool tool, ValueNode forValue) {
  71         if (forValue.isConstant()) {
  72             JavaConstant c = forValue.asJavaConstant();
  73             return ConstantNode.forInt(forValue.getStackKind() == JavaKind.Int ? Integer.bitCount(c.asInt()) : Long.bitCount(c.asLong()));
  74         }
  75         return this;
  76     }
  77 
  78     @Override
  79     public void generate(NodeLIRBuilderTool builder, ArithmeticLIRGeneratorTool gen) {
  80         builder.setResult(this, gen.emitBitCount(builder.operand(getValue())));
  81     }
  82 }