1 /*
2 * Copyright (c) 2011, 2016, 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.GraalOptions.GeneratePIC;
26 import static org.graalvm.compiler.nodeinfo.NodeCycles.CYCLES_1;
27
28 import org.graalvm.compiler.core.common.calc.Condition;
29 import org.graalvm.compiler.core.common.type.AbstractObjectStamp;
30 import org.graalvm.compiler.core.common.type.AbstractPointerStamp;
31 import org.graalvm.compiler.core.common.type.IntegerStamp;
32 import org.graalvm.compiler.debug.GraalError;
33 import org.graalvm.compiler.graph.NodeClass;
34 import org.graalvm.compiler.graph.spi.Canonicalizable;
35 import org.graalvm.compiler.graph.spi.CanonicalizerTool;
36 import org.graalvm.compiler.nodeinfo.NodeInfo;
37 import org.graalvm.compiler.nodes.BinaryOpLogicNode;
38 import org.graalvm.compiler.nodes.ConstantNode;
39 import org.graalvm.compiler.nodes.LogicConstantNode;
40 import org.graalvm.compiler.nodes.LogicNegationNode;
41 import org.graalvm.compiler.nodes.LogicNode;
42 import org.graalvm.compiler.nodes.StructuredGraph;
43 import org.graalvm.compiler.nodes.ValueNode;
44
45 import jdk.vm.ci.meta.Constant;
46 import jdk.vm.ci.meta.ConstantReflectionProvider;
47
48 @NodeInfo(cycles = CYCLES_1)
49 public abstract class CompareNode extends BinaryOpLogicNode implements Canonicalizable.Binary<ValueNode> {
50
51 public static final NodeClass<CompareNode> TYPE = NodeClass.create(CompareNode.class);
52 protected final Condition condition;
53 protected final boolean unorderedIsTrue;
54
55 /**
56 * Constructs a new Compare instruction.
57 *
58 * @param x the instruction producing the first input to the instruction
59 * @param y the instruction that produces the second input to this instruction
60 */
61 protected CompareNode(NodeClass<? extends CompareNode> c, Condition condition, boolean unorderedIsTrue, ValueNode x, ValueNode y) {
62 super(c, x, y);
63 this.condition = condition;
64 this.unorderedIsTrue = unorderedIsTrue;
65 }
66
67 /**
68 * Gets the condition (comparison operation) for this instruction.
69 *
70 * @return the condition
71 */
72 public final Condition condition() {
73 return condition;
74 }
75
76 /**
77 * Checks whether unordered inputs mean true or false (only applies to float operations).
78 *
79 * @return {@code true} if unordered inputs produce true
80 */
81 public final boolean unorderedIsTrue() {
82 return this.unorderedIsTrue;
83 }
84
85 private ValueNode optimizeConditional(Constant constant, ConditionalNode conditionalNode, ConstantReflectionProvider constantReflection, Condition cond) {
86 Constant trueConstant = conditionalNode.trueValue().asConstant();
87 Constant falseConstant = conditionalNode.falseValue().asConstant();
88
89 if (falseConstant != null && trueConstant != null && constantReflection != null) {
90 boolean trueResult = cond.foldCondition(trueConstant, constant, constantReflection, unorderedIsTrue());
91 boolean falseResult = cond.foldCondition(falseConstant, constant, constantReflection, unorderedIsTrue());
92
93 if (trueResult == falseResult) {
94 return LogicConstantNode.forBoolean(trueResult);
95 } else {
96 if (trueResult) {
97 assert falseResult == false;
98 return conditionalNode.condition();
99 } else {
100 assert falseResult == true;
101 return LogicNegationNode.create(conditionalNode.condition());
102
103 }
104 }
105 }
106 return this;
107 }
108
109 protected ValueNode optimizeNormalizeCmp(Constant constant, NormalizeCompareNode normalizeNode, boolean mirrored) {
110 throw new GraalError("NormalizeCompareNode connected to %s (%s %s %s)", this, constant, normalizeNode, mirrored);
111 }
112
113 @Override
114 public ValueNode canonical(CanonicalizerTool tool, ValueNode forX, ValueNode forY) {
115 ConstantReflectionProvider constantReflection = tool.getConstantReflection();
116 LogicNode constantCondition = tryConstantFold(condition(), forX, forY, constantReflection, unorderedIsTrue());
117 if (constantCondition != null) {
118 return constantCondition;
119 }
120 ValueNode result;
121 if (forX.isConstant()) {
122 if ((result = canonicalizeSymmetricConstant(tool, forX.asConstant(), forY, true)) != this) {
123 return result;
124 }
125 } else if (forY.isConstant()) {
126 if ((result = canonicalizeSymmetricConstant(tool, forY.asConstant(), forX, false)) != this) {
127 return result;
128 }
129 } else if (forX instanceof ConvertNode && forY instanceof ConvertNode) {
130 ConvertNode convertX = (ConvertNode) forX;
131 ConvertNode convertY = (ConvertNode) forY;
132 if (convertX.preservesOrder(condition()) && convertY.preservesOrder(condition()) && convertX.getValue().stamp().isCompatible(convertY.getValue().stamp())) {
133 boolean supported = true;
134 if (convertX.getValue().stamp() instanceof IntegerStamp) {
135 IntegerStamp intStamp = (IntegerStamp) convertX.getValue().stamp();
136 supported = tool.supportSubwordCompare(intStamp.getBits());
137 }
138
139 if (supported) {
140 boolean multiUsage = (convertX.asNode().hasMoreThanOneUsage() || convertY.asNode().hasMoreThanOneUsage());
141 if ((forX instanceof ZeroExtendNode || forX instanceof SignExtendNode) && multiUsage) {
142 // Do not perform for zero or sign extend if there are multiple usages of
143 // the value.
144 return this;
145 }
146 return duplicateModified(convertX.getValue(), convertY.getValue());
147 }
148 }
149 }
150 return this;
151 }
152
153 public static LogicNode tryConstantFold(Condition condition, ValueNode forX, ValueNode forY, ConstantReflectionProvider constantReflection, boolean unorderedIsTrue) {
154 if (forX.isConstant() && forY.isConstant() && constantReflection != null) {
155 return LogicConstantNode.forBoolean(condition.foldCondition(forX.asConstant(), forY.asConstant(), constantReflection, unorderedIsTrue));
156 }
157 return null;
158 }
159
160 /**
161 * Does this operation represent an identity check such that for x == y, x is exactly the same
162 * thing as y. This is generally true except for some floating point comparisons.
163 *
164 * @return true for identity comparisons
165 */
166 public boolean isIdentityComparison() {
167 return condition == Condition.EQ;
168 }
169
170 protected abstract LogicNode duplicateModified(ValueNode newX, ValueNode newY);
171
172 protected ValueNode canonicalizeSymmetricConstant(CanonicalizerTool tool, Constant constant, ValueNode nonConstant, boolean mirrored) {
173 if (nonConstant instanceof ConditionalNode) {
174 return optimizeConditional(constant, (ConditionalNode) nonConstant, tool.getConstantReflection(), mirrored ? condition().mirror() : condition());
175 } else if (nonConstant instanceof NormalizeCompareNode) {
176 return optimizeNormalizeCmp(constant, (NormalizeCompareNode) nonConstant, mirrored);
177 } else if (nonConstant instanceof ConvertNode) {
178 ConvertNode convert = (ConvertNode) nonConstant;
179 boolean multiUsage = (convert.asNode().hasMoreThanOneUsage() && convert.getValue().hasExactlyOneUsage());
180 if ((convert instanceof ZeroExtendNode || convert instanceof SignExtendNode) && multiUsage) {
181 // Do not perform for zero or sign extend if it could introduce
182 // new live values.
183 return this;
184 }
185
186 boolean supported = true;
187 if (convert.getValue().stamp() instanceof IntegerStamp) {
188 IntegerStamp intStamp = (IntegerStamp) convert.getValue().stamp();
189 supported = tool.supportSubwordCompare(intStamp.getBits());
190 }
191
192 if (supported) {
193 ConstantNode newConstant = canonicalConvertConstant(tool, convert, constant);
194 if (newConstant != null) {
195 if (mirrored) {
196 return duplicateModified(newConstant, convert.getValue());
197 } else {
198 return duplicateModified(convert.getValue(), newConstant);
199 }
200 }
201 }
202 }
203
204 return this;
205 }
206
207 private ConstantNode canonicalConvertConstant(CanonicalizerTool tool, ConvertNode convert, Constant constant) {
208 ConstantReflectionProvider constantReflection = tool.getConstantReflection();
209 if (convert.preservesOrder(condition(), constant, constantReflection)) {
210 Constant reverseConverted = convert.reverse(constant, constantReflection);
211 if (reverseConverted != null && convert.convert(reverseConverted, constantReflection).equals(constant)) {
212 if (GeneratePIC.getValue(tool.getOptions())) {
213 // We always want uncompressed constants
214 return null;
215 }
216 return ConstantNode.forConstant(convert.getValue().stamp(), reverseConverted, tool.getMetaAccess());
217 }
218 }
219 return null;
220 }
221
222 public static LogicNode createCompareNode(StructuredGraph graph, Condition condition, ValueNode x, ValueNode y, ConstantReflectionProvider constantReflection) {
223 LogicNode result = createCompareNode(condition, x, y, constantReflection);
224 return (result.graph() == null ? graph.unique(result) : result);
225 }
226
227 public static LogicNode createCompareNode(Condition condition, ValueNode x, ValueNode y, ConstantReflectionProvider constantReflection) {
228 assert x.getStackKind() == y.getStackKind();
229 assert condition.isCanonical();
230 assert !x.getStackKind().isNumericFloat();
231
232 LogicNode comparison;
233 if (condition == Condition.EQ) {
234 if (x.stamp() instanceof AbstractObjectStamp) {
235 comparison = ObjectEqualsNode.create(x, y, constantReflection);
236 } else if (x.stamp() instanceof AbstractPointerStamp) {
237 comparison = PointerEqualsNode.create(x, y);
238 } else {
239 assert x.getStackKind().isNumericInteger();
240 comparison = IntegerEqualsNode.create(x, y, constantReflection);
241 }
242 } else if (condition == Condition.LT) {
243 assert x.getStackKind().isNumericInteger();
244 comparison = IntegerLessThanNode.create(x, y, constantReflection);
245 } else {
246 assert condition == Condition.BT;
247 assert x.getStackKind().isNumericInteger();
248 comparison = IntegerBelowNode.create(x, y, constantReflection);
249 }
250
251 return comparison;
252 }
253 }