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.core.common.type.IntegerStamp.addOverflowsNegatively;
28 import static org.graalvm.compiler.core.common.type.IntegerStamp.addOverflowsPositively;
29 import static org.graalvm.compiler.core.common.type.IntegerStamp.carryBits;
30 import static org.graalvm.compiler.nodeinfo.NodeCycles.CYCLES_2;
31 import static org.graalvm.compiler.nodeinfo.NodeSize.SIZE_2;
32
33 import org.graalvm.compiler.core.common.type.IntegerStamp;
34 import org.graalvm.compiler.core.common.type.Stamp;
35 import org.graalvm.compiler.core.common.type.StampFactory;
36 import org.graalvm.compiler.graph.NodeClass;
37 import org.graalvm.compiler.graph.spi.CanonicalizerTool;
38 import org.graalvm.compiler.nodeinfo.InputType;
39 import org.graalvm.compiler.nodeinfo.NodeInfo;
40 import org.graalvm.compiler.nodes.AbstractBeginNode;
41 import org.graalvm.compiler.nodes.ConstantNode;
42 import org.graalvm.compiler.nodes.NodeView;
43 import org.graalvm.compiler.nodes.ValueNode;
44 import org.graalvm.compiler.nodes.calc.AddNode;
45 import org.graalvm.compiler.nodes.extended.AnchoringNode;
46 import org.graalvm.compiler.nodes.spi.LoweringTool;
47
48 import jdk.vm.ci.code.CodeUtil;
49 import jdk.vm.ci.meta.JavaConstant;
50 import jdk.vm.ci.meta.JavaKind;
51 import jdk.vm.ci.meta.SpeculationLog.SpeculationReason;
52
53 /**
54 * Node representing an exact integer addition that will throw an {@link ArithmeticException} in
55 * case the addition would overflow the 32 bit range.
56 */
57 @NodeInfo(cycles = CYCLES_2, size = SIZE_2)
58 public final class IntegerAddExactNode extends AddNode implements IntegerExactArithmeticNode {
59 public static final NodeClass<IntegerAddExactNode> TYPE = NodeClass.create(IntegerAddExactNode.class);
60
61 @OptionalInput(InputType.Anchor) protected AnchoringNode anchor;
62 protected final SpeculationReason speculation;
63
64 public IntegerAddExactNode(ValueNode x, ValueNode y, SpeculationReason speculation) {
65 super(TYPE, x, y);
66 setStamp(x.stamp(NodeView.DEFAULT).unrestricted());
67 assert x.stamp(NodeView.DEFAULT).isCompatible(y.stamp(NodeView.DEFAULT)) && x.stamp(NodeView.DEFAULT) instanceof IntegerStamp;
68 this.speculation = speculation;
69 }
70
71 @Override
72 public boolean inferStamp() {
73 /*
74 * Note: it is not allowed to use the foldStamp method of the regular add node as we do not
75 * know the result stamp of this node if we do not know whether we may deopt. If we know we
76 * can never overflow we will replace this node with its non overflow checking counterpart
77 * anyway.
78 */
79 return false;
80 }
81
82 @Override
83 public Stamp foldStamp(Stamp stampX, Stamp stampY) {
84 IntegerStamp a = (IntegerStamp) stampX;
85 IntegerStamp b = (IntegerStamp) stampY;
86
87 int bits = a.getBits();
88 assert bits == b.getBits();
89
90 long defaultMask = CodeUtil.mask(bits);
91 long variableBits = (a.downMask() ^ a.upMask()) | (b.downMask() ^ b.upMask());
92 long variableBitsWithCarry = variableBits | (carryBits(a.downMask(), b.downMask()) ^ carryBits(a.upMask(), b.upMask()));
93 long newDownMask = (a.downMask() + b.downMask()) & ~variableBitsWithCarry;
94 long newUpMask = (a.downMask() + b.downMask()) | variableBitsWithCarry;
95
96 newDownMask &= defaultMask;
97 newUpMask &= defaultMask;
98
99 long newLowerBound;
100 long newUpperBound;
101 boolean lowerOverflowsPositively = addOverflowsPositively(a.lowerBound(), b.lowerBound(), bits);
102 boolean upperOverflowsPositively = addOverflowsPositively(a.upperBound(), b.upperBound(), bits);
103 boolean lowerOverflowsNegatively = addOverflowsNegatively(a.lowerBound(), b.lowerBound(), bits);
104 boolean upperOverflowsNegatively = addOverflowsNegatively(a.upperBound(), b.upperBound(), bits);
105 if (lowerOverflowsPositively) {
106 newLowerBound = CodeUtil.maxValue(bits);
107 } else if (lowerOverflowsNegatively) {
108 newLowerBound = CodeUtil.minValue(bits);
109 } else {
110 newLowerBound = CodeUtil.signExtend((a.lowerBound() + b.lowerBound()) & defaultMask, bits);
111 }
112
113 if (upperOverflowsPositively) {
114 newUpperBound = CodeUtil.maxValue(bits);
115 } else if (upperOverflowsNegatively) {
116 newUpperBound = CodeUtil.minValue(bits);
117 } else {
118 newUpperBound = CodeUtil.signExtend((a.upperBound() + b.upperBound()) & defaultMask, bits);
119 }
120
121 IntegerStamp limit = StampFactory.forInteger(bits, newLowerBound, newUpperBound);
122 newUpMask &= limit.upMask();
123 newUpperBound = CodeUtil.signExtend(newUpperBound & newUpMask, bits);
124 newDownMask |= limit.downMask();
125 newLowerBound |= newDownMask;
126 return IntegerStamp.create(bits, newLowerBound, newUpperBound, newDownMask, newUpMask);
127 }
128
129 @Override
130 public ValueNode canonical(CanonicalizerTool tool, ValueNode forX, ValueNode forY) {
131 if (forX.isConstant() && !forY.isConstant()) {
132 return new IntegerAddExactNode(forY, forX, speculation).canonical(tool);
133 }
134 if (forX.isConstant()) {
135 ConstantNode constantNode = canonicalXconstant(forX, forY);
136 if (constantNode != null) {
137 return constantNode;
138 }
139 } else if (forY.isConstant()) {
140 long c = forY.asJavaConstant().asLong();
141 if (c == 0) {
142 return forX;
143 }
144 }
145 if (!IntegerStamp.addCanOverflow((IntegerStamp) forX.stamp(NodeView.DEFAULT), (IntegerStamp) forY.stamp(NodeView.DEFAULT))) {
146 return new AddNode(forX, forY).canonical(tool);
147 }
148 return this;
149 }
150
151 private static ConstantNode canonicalXconstant(ValueNode forX, ValueNode forY) {
152 JavaConstant xConst = forX.asJavaConstant();
153 JavaConstant yConst = forY.asJavaConstant();
154 if (xConst != null && yConst != null) {
155 assert xConst.getJavaKind() == yConst.getJavaKind();
156 try {
157 if (xConst.getJavaKind() == JavaKind.Int) {
158 return ConstantNode.forInt(Math.addExact(xConst.asInt(), yConst.asInt()));
159 } else {
160 assert xConst.getJavaKind() == JavaKind.Long;
161 return ConstantNode.forLong(Math.addExact(xConst.asLong(), yConst.asLong()));
162 }
163 } catch (ArithmeticException ex) {
164 // The operation will result in an overflow exception, so do not canonicalize.
165 }
166 }
167 return null;
168 }
169
170 @Override
171 public IntegerExactArithmeticSplitNode createSplit(AbstractBeginNode next, AbstractBeginNode deopt) {
172 return graph().add(new IntegerAddExactSplitNode(stamp(NodeView.DEFAULT), getX(), getY(), next, deopt));
173 }
174
175 @Override
176 public SpeculationReason getSpeculation() {
177 return speculation;
178 }
179
180 @Override
181 public AnchoringNode getAnchor() {
182 return anchor;
183 }
184
185 @Override
186 public void setAnchor(AnchoringNode x) {
187 updateUsagesInterface(this.anchor, x);
188 this.anchor = x;
189 }
190
191 @Override
192 public void lower(LoweringTool tool) {
193 IntegerExactArithmeticSplitNode.lower(tool, this);
194 }
195 }