1 /*
2 * Copyright (c) 2011, 2017, 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.core.common.calc.Condition.LT;
26
27 import org.graalvm.compiler.core.common.NumUtil;
28 import org.graalvm.compiler.core.common.calc.Condition;
29 import org.graalvm.compiler.core.common.type.FloatStamp;
30 import org.graalvm.compiler.core.common.type.IntegerStamp;
31 import org.graalvm.compiler.core.common.type.StampFactory;
32 import org.graalvm.compiler.debug.GraalError;
33 import org.graalvm.compiler.graph.NodeClass;
34 import org.graalvm.compiler.graph.spi.CanonicalizerTool;
35 import org.graalvm.compiler.nodeinfo.NodeInfo;
36 import org.graalvm.compiler.nodes.ConstantNode;
37 import org.graalvm.compiler.nodes.LogicNode;
38 import org.graalvm.compiler.nodes.ValueNode;
39
40 import jdk.vm.ci.code.CodeUtil;
41 import jdk.vm.ci.meta.Constant;
42 import jdk.vm.ci.meta.ConstantReflectionProvider;
43 import jdk.vm.ci.meta.JavaConstant;
44 import jdk.vm.ci.meta.JavaKind;
45 import jdk.vm.ci.meta.PrimitiveConstant;
46
47 @NodeInfo(shortName = "<")
48 public final class IntegerLessThanNode extends IntegerLowerThanNode {
49 public static final NodeClass<IntegerLessThanNode> TYPE = NodeClass.create(IntegerLessThanNode.class);
50 public static final LessThanOp OP = new LessThanOp();
51
52 public IntegerLessThanNode(ValueNode x, ValueNode y) {
53 super(TYPE, x, y, OP);
54 assert !x.getStackKind().isNumericFloat() && x.getStackKind() != JavaKind.Object;
55 assert !y.getStackKind().isNumericFloat() && y.getStackKind() != JavaKind.Object;
56 }
57
58 public static LogicNode create(ValueNode x, ValueNode y, ConstantReflectionProvider constantReflection) {
59 return OP.create(x, y, constantReflection);
60 }
61
62 @Override
63 protected ValueNode optimizeNormalizeCmp(Constant constant, NormalizeCompareNode normalizeNode, boolean mirrored) {
64 PrimitiveConstant primitive = (PrimitiveConstant) constant;
65 assert condition() == LT;
66 if (primitive.getJavaKind() == JavaKind.Int && primitive.asInt() == 0) {
67 ValueNode a = mirrored ? normalizeNode.getY() : normalizeNode.getX();
68 ValueNode b = mirrored ? normalizeNode.getX() : normalizeNode.getY();
69
70 if (normalizeNode.getX().getStackKind() == JavaKind.Double || normalizeNode.getX().getStackKind() == JavaKind.Float) {
71 return new FloatLessThanNode(a, b, mirrored ^ normalizeNode.isUnorderedLess);
72 } else {
73 return new IntegerLessThanNode(a, b);
74 }
75 }
76 return this;
77 }
78
79 public static boolean subtractMayUnderflow(long x, long y, long minValue) {
80 long r = x - y;
81 // HD 2-12 Overflow iff the arguments have different signs and
82 // the sign of the result is different than the sign of x
83 return (((x ^ y) & (x ^ r)) < 0) || r <= minValue;
84 }
85
86 public static boolean subtractMayOverflow(long x, long y, long maxValue) {
87 long r = x - y;
88 // HD 2-12 Overflow iff the arguments have different signs and
89 // the sign of the result is different than the sign of x
90 return (((x ^ y) & (x ^ r)) < 0) || r > maxValue;
91 }
92
93 @Override
94 public ValueNode canonical(CanonicalizerTool tool, ValueNode forX, ValueNode forY) {
95 ValueNode result = super.canonical(tool, forX, forY);
96 if (result != this) {
97 return result;
98 }
99 if (forX.stamp() instanceof IntegerStamp && forY.stamp() instanceof IntegerStamp) {
100 if (IntegerStamp.sameSign((IntegerStamp) forX.stamp(), (IntegerStamp) forY.stamp())) {
101 return new IntegerBelowNode(forX, forY);
102 }
103 }
104 if (forY.isConstant() && forY.asConstant().isDefaultForKind() && forX instanceof SubNode) {
105 // (x - y) < 0 when x - y is known not to underflow <=> x < y
106 SubNode sub = (SubNode) forX;
107 IntegerStamp xStamp = (IntegerStamp) sub.getX().stamp();
108 IntegerStamp yStamp = (IntegerStamp) sub.getY().stamp();
109 long minValue = CodeUtil.minValue(xStamp.getBits());
110 long maxValue = CodeUtil.maxValue(xStamp.getBits());
111
112 if (!subtractMayUnderflow(xStamp.lowerBound(), yStamp.upperBound(), minValue) && !subtractMayOverflow(xStamp.upperBound(), yStamp.lowerBound(), maxValue)) {
113 return new IntegerLessThanNode(sub.getX(), sub.getY());
114 }
115 }
116
117 int bits = ((IntegerStamp) getX().stamp()).getBits();
118 assert ((IntegerStamp) getY().stamp()).getBits() == bits;
119 long min = OP.minValue(bits);
120 long xResidue = 0;
121 ValueNode left = null;
122 JavaConstant leftCst = null;
123 if (forX instanceof AddNode) {
124 AddNode xAdd = (AddNode) forX;
125 if (xAdd.getY().isJavaConstant()) {
126 long xCst = xAdd.getY().asJavaConstant().asLong();
127 xResidue = xCst - min;
128 left = xAdd.getX();
129 }
130 } else if (forX.isJavaConstant()) {
131 leftCst = forX.asJavaConstant();
132 }
133 if (left != null || leftCst != null) {
134 long yResidue = 0;
135 ValueNode right = null;
136 JavaConstant rightCst = null;
137 if (forY instanceof AddNode) {
138 AddNode yAdd = (AddNode) forY;
139 if (yAdd.getY().isJavaConstant()) {
140 long yCst = yAdd.getY().asJavaConstant().asLong();
141 yResidue = yCst - min;
142 right = yAdd.getX();
143 }
144 } else if (forY.isJavaConstant()) {
145 rightCst = forY.asJavaConstant();
146 }
147 if (right != null || rightCst != null) {
148 if ((xResidue == 0 && left != null) || (yResidue == 0 && right != null)) {
149 if (left == null) {
150 left = ConstantNode.forIntegerBits(bits, leftCst.asLong() - min);
151 } else if (xResidue != 0) {
152 left = AddNode.create(left, ConstantNode.forIntegerBits(bits, xResidue));
153 }
154 if (right == null) {
155 right = ConstantNode.forIntegerBits(bits, rightCst.asLong() - min);
156 } else if (yResidue != 0) {
157 right = AddNode.create(right, ConstantNode.forIntegerBits(bits, yResidue));
158 }
159 return new IntegerBelowNode(left, right);
160 }
161 }
162 }
163 return this;
164 }
165
166 @Override
167 protected CompareNode duplicateModified(ValueNode newX, ValueNode newY) {
168 if (newX.stamp() instanceof FloatStamp && newY.stamp() instanceof FloatStamp) {
169 return new FloatLessThanNode(newX, newY, true);
170 } else if (newX.stamp() instanceof IntegerStamp && newY.stamp() instanceof IntegerStamp) {
171 return new IntegerLessThanNode(newX, newY);
172 }
173 throw GraalError.shouldNotReachHere();
174 }
175
176 public static class LessThanOp extends LowerOp {
177
178 @Override
179 protected Condition getCondition() {
180 return LT;
181 }
182
183 @Override
184 protected IntegerLowerThanNode create(ValueNode x, ValueNode y) {
185 return new IntegerLessThanNode(x, y);
186 }
187
188 @Override
189 protected long upperBound(IntegerStamp stamp) {
190 return stamp.upperBound();
191 }
192
193 @Override
194 protected long lowerBound(IntegerStamp stamp) {
195 return stamp.lowerBound();
196 }
197
198 @Override
199 protected int compare(long a, long b) {
200 return Long.compare(a, b);
201 }
202
203 @Override
204 protected long min(long a, long b) {
205 return Math.min(a, b);
206 }
207
208 @Override
209 protected long max(long a, long b) {
210 return Math.max(a, b);
211 }
212
213 @Override
214 protected long cast(long a, int bits) {
215 return CodeUtil.signExtend(a, bits);
216 }
217
218 @Override
219 protected long minValue(int bits) {
220 return NumUtil.minValue(bits);
221 }
222
223 @Override
224 protected long maxValue(int bits) {
225 return NumUtil.maxValue(bits);
226 }
227
228 @Override
229 protected IntegerStamp forInteger(int bits, long min, long max) {
230 return StampFactory.forInteger(bits, cast(min, bits), cast(max, bits));
231 }
232 }
233 }