1 /*
   2  * Copyright (c) 2017, 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 
  24 
  25 package org.graalvm.compiler.nodes.calc;
  26 
  27 import java.nio.ByteOrder;
  28 
  29 import org.graalvm.compiler.core.common.type.StampFactory;
  30 import org.graalvm.compiler.graph.Node;
  31 import org.graalvm.compiler.graph.NodeClass;
  32 import org.graalvm.compiler.graph.spi.CanonicalizerTool;
  33 import org.graalvm.compiler.nodeinfo.NodeCycles;
  34 import org.graalvm.compiler.nodeinfo.NodeInfo;
  35 import org.graalvm.compiler.nodes.ConstantNode;
  36 import org.graalvm.compiler.nodes.NodeView;
  37 import org.graalvm.compiler.nodes.ValueNode;
  38 import org.graalvm.compiler.nodes.spi.Lowerable;
  39 import org.graalvm.compiler.nodes.spi.LoweringTool;
  40 
  41 import jdk.vm.ci.meta.JavaKind;
  42 
  43 /**
  44  * Produces the platform dependent first or second half of a long or double value as an int.
  45  */
  46 @NodeInfo(cycles = NodeCycles.CYCLES_2)
  47 public final class UnpackEndianHalfNode extends UnaryNode implements Lowerable {
  48     public static final NodeClass<UnpackEndianHalfNode> TYPE = NodeClass.create(UnpackEndianHalfNode.class);
  49 
  50     private final boolean firstHalf;
  51 
  52     protected UnpackEndianHalfNode(ValueNode value, boolean firstHalf) {
  53         super(TYPE, StampFactory.forKind(JavaKind.Int), value);
  54         assert value.getStackKind() == JavaKind.Double || value.getStackKind() == JavaKind.Long : "unexpected kind " + value.getStackKind();
  55         this.firstHalf = firstHalf;
  56     }
  57 
  58     @SuppressWarnings("unused")
  59     public static ValueNode create(ValueNode value, boolean firstHalf, NodeView view) {
  60         if (value.isConstant() && value.asConstant().isDefaultForKind()) {
  61             return ConstantNode.defaultForKind(JavaKind.Int);
  62         }
  63         return new UnpackEndianHalfNode(value, firstHalf);
  64     }
  65 
  66     public boolean isFirstHalf() {
  67         return firstHalf;
  68     }
  69 
  70     @Override
  71     public Node canonical(CanonicalizerTool tool, ValueNode forValue) {
  72         if (forValue.isDefaultConstant()) {
  73             return ConstantNode.defaultForKind(stamp.getStackKind());
  74         }
  75         return this;
  76     }
  77 
  78     @Override
  79     public void lower(LoweringTool tool) {
  80         tool.getLowerer().lower(this, tool);
  81     }
  82 
  83     public void lower(ByteOrder byteOrder) {
  84         ValueNode result = value;
  85         if (value.getStackKind() == JavaKind.Double) {
  86             result = graph().unique(new ReinterpretNode(JavaKind.Long, value));
  87         }
  88         if ((byteOrder == ByteOrder.BIG_ENDIAN) == firstHalf) {
  89             result = graph().unique(new UnsignedRightShiftNode(result, ConstantNode.forInt(32, graph())));
  90         }
  91         result = IntegerConvertNode.convert(result, StampFactory.forKind(JavaKind.Int), graph(), NodeView.DEFAULT);
  92         replaceAtUsagesAndDelete(result);
  93     }
  94 }