1 /*
2 * Copyright (c) 2013, 2018, 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_2;
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.InputType;
34 import org.graalvm.compiler.nodeinfo.NodeInfo;
35 import org.graalvm.compiler.nodes.AbstractBeginNode;
36 import org.graalvm.compiler.nodes.ConstantNode;
37 import org.graalvm.compiler.nodes.NodeView;
38 import org.graalvm.compiler.nodes.ValueNode;
39 import org.graalvm.compiler.nodes.calc.SubNode;
40 import org.graalvm.compiler.nodes.extended.AnchoringNode;
41 import org.graalvm.compiler.nodes.spi.LoweringTool;
42 import org.graalvm.compiler.nodes.util.GraphUtil;
43
44 import jdk.vm.ci.meta.JavaConstant;
45 import jdk.vm.ci.meta.JavaKind;
46 import jdk.vm.ci.meta.SpeculationLog.SpeculationReason;
47
48 /**
49 * Node representing an exact integer substraction that will throw an {@link ArithmeticException} in
50 * case the addition would overflow the 32 bit range.
51 */
52 @NodeInfo(cycles = CYCLES_2, size = SIZE_2)
53 public final class IntegerSubExactNode extends SubNode implements IntegerExactArithmeticNode {
54 public static final NodeClass<IntegerSubExactNode> TYPE = NodeClass.create(IntegerSubExactNode.class);
55
56 @OptionalInput(InputType.Anchor) protected AnchoringNode anchor;
57 protected final SpeculationReason speculation;
58
59 public IntegerSubExactNode(ValueNode x, ValueNode y, SpeculationReason speculation) {
60 super(TYPE, x, y);
61 setStamp(x.stamp(NodeView.DEFAULT).unrestricted());
62 assert x.stamp(NodeView.DEFAULT).isCompatible(y.stamp(NodeView.DEFAULT)) && x.stamp(NodeView.DEFAULT) instanceof IntegerStamp;
63 this.speculation = speculation;
64 }
65
66 @Override
67 public boolean inferStamp() {
68 /*
69 * Note: it is not allowed to use the foldStamp method of the regular sub node as we do not
70 * know the result stamp of this node if we do not know whether we may deopt. If we know we
71 * can never overflow we will replace this node with its non overflow checking counterpart
72 * anyway.
73 */
74 return false;
75 }
76
77 @Override
78 public ValueNode canonical(CanonicalizerTool tool, ValueNode forX, ValueNode forY) {
79 if (GraphUtil.unproxify(forX) == GraphUtil.unproxify(forY)) {
80 return ConstantNode.forIntegerStamp(stamp(NodeView.DEFAULT), 0);
81 }
82 if (forX.isConstant() && forY.isConstant()) {
83 return canonicalXYconstant(forX, forY);
84 } else if (forY.isConstant()) {
85 long c = forY.asJavaConstant().asLong();
86 if (c == 0) {
87 return forX;
88 }
89 }
90 if (!IntegerStamp.subtractionCanOverflow((IntegerStamp) x.stamp(NodeView.DEFAULT), (IntegerStamp) y.stamp(NodeView.DEFAULT))) {
91 return new SubNode(x, y).canonical(tool);
92 }
93 return this;
94 }
95
96 private ValueNode canonicalXYconstant(ValueNode forX, ValueNode forY) {
97 JavaConstant xConst = forX.asJavaConstant();
98 JavaConstant yConst = forY.asJavaConstant();
99 assert xConst.getJavaKind() == yConst.getJavaKind();
100 try {
101 if (xConst.getJavaKind() == JavaKind.Int) {
102 return ConstantNode.forInt(Math.subtractExact(xConst.asInt(), yConst.asInt()));
103 } else {
104 assert xConst.getJavaKind() == JavaKind.Long;
105 return ConstantNode.forLong(Math.subtractExact(xConst.asLong(), yConst.asLong()));
106 }
107 } catch (ArithmeticException ex) {
108 // The operation will result in an overflow exception, so do not canonicalize.
109 }
110 return this;
111 }
112
113 @Override
114 public IntegerExactArithmeticSplitNode createSplit(AbstractBeginNode next, AbstractBeginNode deopt) {
115 return graph().add(new IntegerSubExactSplitNode(stamp(NodeView.DEFAULT), getX(), getY(), next, deopt));
116 }
117
118 @Override
119 public SpeculationReason getSpeculation() {
120 return speculation;
121 }
122
123 @Override
124 public AnchoringNode getAnchor() {
125 return anchor;
126 }
127
128 @Override
129 public void setAnchor(AnchoringNode x) {
130 updateUsagesInterface(this.anchor, x);
131 this.anchor = x;
132 }
133
134 @Override
135 public void lower(LoweringTool tool) {
136 IntegerExactArithmeticSplitNode.lower(tool, this);
137 }
138 }