1 /*
   2  * Copyright (c) 2011, 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.nodes.calc;
  24 
  25 import static org.graalvm.compiler.nodeinfo.NodeCycles.CYCLES_32;
  26 
  27 import org.graalvm.compiler.core.common.type.ArithmeticOpTable;
  28 import org.graalvm.compiler.core.common.type.ArithmeticOpTable.BinaryOp;
  29 import org.graalvm.compiler.core.common.type.ArithmeticOpTable.BinaryOp.Div;
  30 import org.graalvm.compiler.core.common.type.Stamp;
  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.spi.NodeLIRBuilderTool;
  38 
  39 import jdk.vm.ci.code.CodeUtil;
  40 import jdk.vm.ci.meta.Constant;
  41 import jdk.vm.ci.meta.PrimitiveConstant;
  42 
  43 @NodeInfo(shortName = "/", cycles = CYCLES_32)
  44 public class DivNode extends BinaryArithmeticNode<Div> {
  45 
  46     public static final NodeClass<DivNode> TYPE = NodeClass.create(DivNode.class);
  47 
  48     public DivNode(ValueNode x, ValueNode y) {
  49         super(TYPE, ArithmeticOpTable::getDiv, x, y);
  50     }
  51 
  52     protected DivNode(NodeClass<? extends DivNode> c, ValueNode x, ValueNode y) {
  53         super(c, ArithmeticOpTable::getDiv, x, y);
  54     }
  55 
  56     public static ValueNode create(ValueNode x, ValueNode y) {
  57         BinaryOp<Div> op = ArithmeticOpTable.forStamp(x.stamp()).getDiv();
  58         Stamp stamp = op.foldStamp(x.stamp(), y.stamp());
  59         ConstantNode tryConstantFold = tryConstantFold(op, x, y, stamp);
  60         if (tryConstantFold != null) {
  61             return tryConstantFold;
  62         }
  63         return canonical(null, op, x, y);
  64     }
  65 
  66     @Override
  67     public ValueNode canonical(CanonicalizerTool tool, ValueNode forX, ValueNode forY) {
  68         ValueNode ret = super.canonical(tool, forX, forY);
  69         if (ret != this) {
  70             return ret;
  71         }
  72 
  73         return canonical(this, getOp(forX, forY), forX, forY);
  74     }
  75 
  76     private static ValueNode canonical(DivNode self, BinaryOp<Div> op, ValueNode forX, ValueNode forY) {
  77         if (forY.isConstant()) {
  78             Constant c = forY.asConstant();
  79             if (op.isNeutral(c)) {
  80                 return forX;
  81             }
  82             if (c instanceof PrimitiveConstant && ((PrimitiveConstant) c).getJavaKind().isNumericInteger()) {
  83                 long i = ((PrimitiveConstant) c).asLong();
  84                 boolean signFlip = false;
  85                 if (i < 0) {
  86                     i = -i;
  87                     signFlip = true;
  88                 }
  89                 ValueNode divResult = null;
  90                 if (CodeUtil.isPowerOf2(i)) {
  91                     divResult = new RightShiftNode(forX, ConstantNode.forInt(CodeUtil.log2(i)));
  92                 }
  93                 if (divResult != null) {
  94                     if (signFlip) {
  95                         return NegateNode.create(divResult);
  96                     } else {
  97                         return divResult;
  98                     }
  99                 }
 100             }
 101         }
 102         return self != null ? self : new DivNode(forX, forY);
 103     }
 104 
 105     @Override
 106     public void generate(NodeLIRBuilderTool nodeValueMap, ArithmeticLIRGeneratorTool gen) {
 107         nodeValueMap.setResult(this, gen.emitDiv(nodeValueMap.operand(getX()), nodeValueMap.operand(getY()), null));
 108     }
 109 }