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 
  24 
  25 package org.graalvm.compiler.loop;
  26 
  27 import static org.graalvm.compiler.loop.MathUtil.mul;
  28 
  29 import org.graalvm.compiler.core.common.type.IntegerStamp;
  30 import org.graalvm.compiler.core.common.type.Stamp;
  31 import org.graalvm.compiler.nodes.ConstantNode;
  32 import org.graalvm.compiler.nodes.NodeView;
  33 import org.graalvm.compiler.nodes.ValueNode;
  34 import org.graalvm.compiler.nodes.calc.IntegerConvertNode;
  35 import org.graalvm.compiler.nodes.calc.NegateNode;
  36 import org.graalvm.compiler.nodes.util.GraphUtil;
  37 
  38 public class DerivedScaledInductionVariable extends DerivedInductionVariable {
  39 
  40     private final ValueNode scale;
  41     private final ValueNode value;
  42 
  43     public DerivedScaledInductionVariable(LoopEx loop, InductionVariable base, ValueNode scale, ValueNode value) {
  44         super(loop, base);
  45         this.scale = scale;
  46         this.value = value;
  47     }
  48 
  49     public DerivedScaledInductionVariable(LoopEx loop, InductionVariable base, NegateNode value) {
  50         super(loop, base);
  51         this.scale = ConstantNode.forIntegerStamp(value.stamp(NodeView.DEFAULT), -1, value.graph());
  52         this.value = value;
  53     }
  54 
  55     public ValueNode getScale() {
  56         return scale;
  57     }
  58 
  59     @Override
  60     public ValueNode valueNode() {
  61         return value;
  62     }
  63 
  64     @Override
  65     public Direction direction() {
  66         Stamp stamp = scale.stamp(NodeView.DEFAULT);
  67         if (stamp instanceof IntegerStamp) {
  68             IntegerStamp integerStamp = (IntegerStamp) stamp;
  69             if (integerStamp.isStrictlyPositive()) {
  70                 return base.direction();
  71             } else if (integerStamp.isStrictlyNegative()) {
  72                 return base.direction().opposite();
  73             }
  74         }
  75         return null;
  76     }
  77 
  78     @Override
  79     public ValueNode initNode() {
  80         return mul(graph(), base.initNode(), scale);
  81     }
  82 
  83     @Override
  84     public ValueNode strideNode() {
  85         return mul(graph(), base.strideNode(), scale);
  86     }
  87 
  88     @Override
  89     public boolean isConstantInit() {
  90         return scale.isConstant() && base.isConstantInit();
  91     }
  92 
  93     @Override
  94     public boolean isConstantStride() {
  95         return scale.isConstant() && base.isConstantStride();
  96     }
  97 
  98     @Override
  99     public long constantInit() {
 100         return base.constantInit() * scale.asJavaConstant().asLong();
 101     }
 102 
 103     @Override
 104     public long constantStride() {
 105         return base.constantStride() * scale.asJavaConstant().asLong();
 106     }
 107 
 108     @Override
 109     public ValueNode extremumNode(boolean assumePositiveTripCount, Stamp stamp) {
 110         return mul(graph(), base.extremumNode(assumePositiveTripCount, stamp), IntegerConvertNode.convert(scale, stamp, graph(), NodeView.DEFAULT));
 111     }
 112 
 113     @Override
 114     public ValueNode exitValueNode() {
 115         return mul(graph(), base.exitValueNode(), scale);
 116     }
 117 
 118     @Override
 119     public boolean isConstantExtremum() {
 120         return scale.isConstant() && base.isConstantExtremum();
 121     }
 122 
 123     @Override
 124     public long constantExtremum() {
 125         return base.constantExtremum() * scale.asJavaConstant().asLong();
 126     }
 127 
 128     @Override
 129     public void deleteUnusedNodes() {
 130         GraphUtil.tryKillUnused(scale);
 131     }
 132 
 133     @Override
 134     public String toString() {
 135         return String.format("DerivedScaleInductionVariable base (%s) %s %s", base, value.getNodeClass().shortName(), scale);
 136     }
 137 }