1/*
2 * Copyright (c) 2013, 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 */
23package org.graalvm.compiler.replacements.nodes;
24
25import static org.graalvm.compiler.nodeinfo.InputType.Memory;
26import static org.graalvm.compiler.nodeinfo.NodeCycles.CYCLES_1024;
27import static org.graalvm.compiler.nodeinfo.NodeSize.SIZE_1024;
28
29import org.graalvm.compiler.core.common.type.StampFactory;
30import org.graalvm.compiler.graph.Node;
31import org.graalvm.compiler.graph.NodeClass;
32import org.graalvm.compiler.graph.spi.Canonicalizable;
33import org.graalvm.compiler.graph.spi.CanonicalizerTool;
34import org.graalvm.compiler.nodeinfo.NodeInfo;
35import org.graalvm.compiler.nodes.ConstantNode;
36import org.graalvm.compiler.nodes.FixedWithNextNode;
37import org.graalvm.compiler.nodes.NamedLocationIdentity;
38import org.graalvm.compiler.nodes.ValueNode;
39import org.graalvm.compiler.nodes.ValueNodeUtil;
40import org.graalvm.compiler.nodes.memory.MemoryAccess;
41import org.graalvm.compiler.nodes.memory.MemoryNode;
42import org.graalvm.compiler.nodes.spi.LIRLowerable;
43import org.graalvm.compiler.nodes.spi.NodeLIRBuilderTool;
44import org.graalvm.compiler.nodes.spi.Virtualizable;
45import org.graalvm.compiler.nodes.spi.VirtualizerTool;
46import org.graalvm.compiler.nodes.util.GraphUtil;
47import org.graalvm.compiler.nodes.virtual.VirtualObjectNode;
48import org.graalvm.word.LocationIdentity;
49
50import jdk.vm.ci.meta.ConstantReflectionProvider;
51import jdk.vm.ci.meta.JavaConstant;
52import jdk.vm.ci.meta.JavaKind;
53import jdk.vm.ci.meta.Value;
54
55// JaCoCo Exclude
56
57/**
58 * Compares two arrays with the same length.
59 */
60@NodeInfo(cycles = CYCLES_1024, size = SIZE_1024)
61public final class ArrayEqualsNode extends FixedWithNextNode implements LIRLowerable, Canonicalizable, Virtualizable, MemoryAccess {
62
63    public static final NodeClass<ArrayEqualsNode> TYPE = NodeClass.create(ArrayEqualsNode.class);
64    /** {@link JavaKind} of the arrays to compare. */
65    protected final JavaKind kind;
66
67    /** One array to be tested for equality. */
68    @Input ValueNode array1;
69
70    /** The other array to be tested for equality. */
71    @Input ValueNode array2;
72
73    /** Length of both arrays. */
74    @Input ValueNode length;
75
76    @OptionalInput(Memory) MemoryNode lastLocationAccess;
77
78    public ArrayEqualsNode(ValueNode array1, ValueNode array2, ValueNode length, @ConstantNodeParameter JavaKind kind) {
79        super(TYPE, StampFactory.forKind(JavaKind.Boolean));
80        this.kind = kind;
81        this.array1 = array1;
82        this.array2 = array2;
83        this.length = length;
84    }
85
86    public ValueNode getArray1() {
87        return array1;
88    }
89
90    public ValueNode getArray2() {
91        return array2;
92    }
93
94    public ValueNode getLength() {
95        return length;
96    }
97
98    private static boolean isNaNFloat(JavaConstant constant) {
99        JavaKind kind = constant.getJavaKind();
100        return (kind == JavaKind.Float && Float.isNaN(constant.asFloat())) || (kind == JavaKind.Double && Double.isNaN(constant.asDouble()));
101    }
102
103    private static boolean arrayEquals(ConstantReflectionProvider constantReflection, JavaConstant a, JavaConstant b, int len) {
104        for (int i = 0; i < len; i++) {
105            JavaConstant aElem = constantReflection.readArrayElement(a, i);
106            JavaConstant bElem = constantReflection.readArrayElement(b, i);
107            if (!constantReflection.constantEquals(aElem, bElem) && !(isNaNFloat(aElem) && isNaNFloat(bElem))) {
108                return false;
109            }
110        }
111        return true;
112    }
113
114    @Override
115    public Node canonical(CanonicalizerTool tool) {
116        if (tool.allUsagesAvailable() && hasNoUsages()) {
117            return null;
118        }
119        ValueNode a1 = GraphUtil.unproxify(array1);
120        ValueNode a2 = GraphUtil.unproxify(array2);
121        if (a1 == a2) {
122            return ConstantNode.forBoolean(true);
123        }
124        if (a1.isConstant() && a2.isConstant() && length.isConstant()) {
125            ConstantNode c1 = (ConstantNode) a1;
126            ConstantNode c2 = (ConstantNode) a2;
127            if (c1.getStableDimension() >= 1 && c2.getStableDimension() >= 1) {
128                boolean ret = arrayEquals(tool.getConstantReflection(), c1.asJavaConstant(), c2.asJavaConstant(), length.asJavaConstant().asInt());
129                return ConstantNode.forBoolean(ret);
130            }
131        }
132        return this;
133    }
134
135    @Override
136    public void virtualize(VirtualizerTool tool) {
137        ValueNode alias1 = tool.getAlias(array1);
138        ValueNode alias2 = tool.getAlias(array2);
139        if (alias1 == alias2) {
140            // the same virtual objects will always have the same contents
141            tool.replaceWithValue(ConstantNode.forBoolean(true, graph()));
142        } else if (alias1 instanceof VirtualObjectNode && alias2 instanceof VirtualObjectNode) {
143            VirtualObjectNode virtual1 = (VirtualObjectNode) alias1;
144            VirtualObjectNode virtual2 = (VirtualObjectNode) alias2;
145
146            if (virtual1.entryCount() == virtual2.entryCount()) {
147                int entryCount = virtual1.entryCount();
148                boolean allEqual = true;
149                for (int i = 0; i < entryCount; i++) {
150                    ValueNode entry1 = tool.getEntry(virtual1, i);
151                    ValueNode entry2 = tool.getEntry(virtual2, i);
152                    if (entry1 != entry2) {
153                        if (entry1 instanceof ConstantNode && entry2 instanceof ConstantNode) {
154                            // Float NaN constants are different constant nodes but treated as
155                            // equal in Arrays.equals([F[F) or Arrays.equals([D[D).
156                            if (entry1.getStackKind() == JavaKind.Float && entry2.getStackKind() == JavaKind.Float) {
157                                float value1 = ((JavaConstant) ((ConstantNode) entry1).asConstant()).asFloat();
158                                float value2 = ((JavaConstant) ((ConstantNode) entry2).asConstant()).asFloat();
159                                if (Float.floatToIntBits(value1) != Float.floatToIntBits(value2)) {
160                                    allEqual = false;
161                                }
162                            } else if (entry1.getStackKind() == JavaKind.Double && entry2.getStackKind() == JavaKind.Double) {
163                                double value1 = ((JavaConstant) ((ConstantNode) entry1).asConstant()).asDouble();
164                                double value2 = ((JavaConstant) ((ConstantNode) entry2).asConstant()).asDouble();
165                                if (Double.doubleToLongBits(value1) != Double.doubleToLongBits(value2)) {
166                                    allEqual = false;
167                                }
168                            } else {
169                                allEqual = false;
170                            }
171                        } else {
172                            // the contents might be different
173                            allEqual = false;
174                        }
175                    }
176                    if (entry1.stamp().alwaysDistinct(entry2.stamp())) {
177                        // the contents are different
178                        tool.replaceWithValue(ConstantNode.forBoolean(false, graph()));
179                        return;
180                    }
181                }
182                if (allEqual) {
183                    tool.replaceWithValue(ConstantNode.forBoolean(true, graph()));
184                }
185            }
186        }
187    }
188
189    @NodeIntrinsic
190    public static native boolean equals(Object array1, Object array2, int length, @ConstantNodeParameter JavaKind kind);
191
192    public static boolean equals(boolean[] array1, boolean[] array2, int length) {
193        return equals(array1, array2, length, JavaKind.Boolean);
194    }
195
196    public static boolean equals(byte[] array1, byte[] array2, int length) {
197        return equals(array1, array2, length, JavaKind.Byte);
198    }
199
200    public static boolean equals(char[] array1, char[] array2, int length) {
201        return equals(array1, array2, length, JavaKind.Char);
202    }
203
204    public static boolean equals(short[] array1, short[] array2, int length) {
205        return equals(array1, array2, length, JavaKind.Short);
206    }
207
208    public static boolean equals(int[] array1, int[] array2, int length) {
209        return equals(array1, array2, length, JavaKind.Int);
210    }
211
212    public static boolean equals(long[] array1, long[] array2, int length) {
213        return equals(array1, array2, length, JavaKind.Long);
214    }
215
216    public static boolean equals(float[] array1, float[] array2, int length) {
217        return equals(array1, array2, length, JavaKind.Float);
218    }
219
220    public static boolean equals(double[] array1, double[] array2, int length) {
221        return equals(array1, array2, length, JavaKind.Double);
222    }
223
224    @Override
225    public void generate(NodeLIRBuilderTool gen) {
226        Value result = gen.getLIRGeneratorTool().emitArrayEquals(kind, gen.operand(array1), gen.operand(array2), gen.operand(length));
227        gen.setResult(this, result);
228    }
229
230    @Override
231    public LocationIdentity getLocationIdentity() {
232        return NamedLocationIdentity.getArrayLocation(kind);
233    }
234
235    @Override
236    public MemoryNode getLastLocationAccess() {
237        return lastLocationAccess;
238    }
239
240    @Override
241    public void setLastLocationAccess(MemoryNode lla) {
242        updateUsages(ValueNodeUtil.asNode(lastLocationAccess), ValueNodeUtil.asNode(lla));
243        lastLocationAccess = lla;
244    }
245}
246