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