1 /*
2  * Copyright (c) 2013, 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.replacements.nodes.arithmetic;
26 
27 import static org.graalvm.compiler.nodeinfo.NodeCycles.CYCLES_4;
28 import static org.graalvm.compiler.nodeinfo.NodeSize.SIZE_2;
29 
30 import org.graalvm.compiler.core.common.type.IntegerStamp;
31 import org.graalvm.compiler.graph.NodeClass;
32 import org.graalvm.compiler.graph.spi.CanonicalizerTool;
33 import org.graalvm.compiler.nodeinfo.NodeInfo;
34 import org.graalvm.compiler.nodes.AbstractBeginNode;
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.calc.MulNode;
39 import org.graalvm.compiler.nodes.spi.LoweringTool;
40 
41 import jdk.vm.ci.meta.JavaConstant;
42 import jdk.vm.ci.meta.JavaKind;
43 
44 /**
45  * Node representing an exact integer multiplication that will throw an {@link ArithmeticException}
46  * in case the addition would overflow the 32 bit range.
47  */
48 @NodeInfo(cycles = CYCLES_4, cyclesRationale = "mul+cmp", size = SIZE_2)
49 public final class IntegerMulExactNode extends MulNode implements IntegerExactArithmeticNode {
50     public static final NodeClass<IntegerMulExactNode> TYPE = NodeClass.create(IntegerMulExactNode.class);
51 
IntegerMulExactNode(ValueNode x, ValueNode y)52     public IntegerMulExactNode(ValueNode x, ValueNode y) {
53         super(TYPE, x, y);
54         setStamp(x.stamp(NodeView.DEFAULT).unrestricted());
55         assert x.stamp(NodeView.DEFAULT).isCompatible(y.stamp(NodeView.DEFAULT)) && x.stamp(NodeView.DEFAULT) instanceof IntegerStamp;
56     }
57 
58     @Override
inferStamp()59     public boolean inferStamp() {
60         /*
61          * Note: it is not allowed to use the foldStamp method of the regular mul node as we do not
62          * know the result stamp of this node if we do not know whether we may deopt. If we know we
63          * can never overflow we will replace this node with its non overflow checking counterpart
64          * anyway.
65          */
66         return false;
67     }
68 
69     @Override
canonical(CanonicalizerTool tool, ValueNode forX, ValueNode forY)70     public ValueNode canonical(CanonicalizerTool tool, ValueNode forX, ValueNode forY) {
71         if (forX.isConstant() && !forY.isConstant()) {
72             return new IntegerMulExactNode(forY, forX).canonical(tool);
73         }
74         if (forX.isConstant()) {
75             return canonicalXconstant(forX, forY);
76         } else if (forY.isConstant()) {
77             long c = forY.asJavaConstant().asLong();
78             if (c == 1) {
79                 return forX;
80             }
81             if (c == 0) {
82                 return ConstantNode.forIntegerStamp(stamp(NodeView.DEFAULT), 0);
83             }
84         }
85         if (!IntegerStamp.multiplicationCanOverflow((IntegerStamp) x.stamp(NodeView.DEFAULT), (IntegerStamp) y.stamp(NodeView.DEFAULT))) {
86             return new MulNode(x, y).canonical(tool);
87         }
88         return this;
89     }
90 
canonicalXconstant(ValueNode forX, ValueNode forY)91     private ValueNode canonicalXconstant(ValueNode forX, ValueNode forY) {
92         JavaConstant xConst = forX.asJavaConstant();
93         JavaConstant yConst = forY.asJavaConstant();
94         assert xConst.getJavaKind() == yConst.getJavaKind();
95         try {
96             if (xConst.getJavaKind() == JavaKind.Int) {
97                 return ConstantNode.forInt(Math.multiplyExact(xConst.asInt(), yConst.asInt()));
98             } else {
99                 assert xConst.getJavaKind() == JavaKind.Long;
100                 return ConstantNode.forLong(Math.multiplyExact(xConst.asLong(), yConst.asLong()));
101             }
102         } catch (ArithmeticException ex) {
103             // The operation will result in an overflow exception, so do not canonicalize.
104         }
105         return this;
106     }
107 
108     @Override
createSplit(AbstractBeginNode next, AbstractBeginNode deopt)109     public IntegerExactArithmeticSplitNode createSplit(AbstractBeginNode next, AbstractBeginNode deopt) {
110         return graph().add(new IntegerMulExactSplitNode(stamp(NodeView.DEFAULT), getX(), getY(), next, deopt));
111     }
112 
113     @Override
lower(LoweringTool tool)114     public void lower(LoweringTool tool) {
115         IntegerExactArithmeticSplitNode.lower(tool, this);
116     }
117 }
118