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 */
23 package org.graalvm.compiler.lir.sparc;
24
25 import static org.graalvm.compiler.asm.sparc.SPARCAssembler.BPCC;
26 import static org.graalvm.compiler.asm.sparc.SPARCAssembler.Annul.ANNUL;
27 import static org.graalvm.compiler.asm.sparc.SPARCAssembler.Annul.NOT_ANNUL;
28 import static org.graalvm.compiler.asm.sparc.SPARCAssembler.BranchPredict.PREDICT_NOT_TAKEN;
29 import static org.graalvm.compiler.asm.sparc.SPARCAssembler.BranchPredict.PREDICT_TAKEN;
30 import static org.graalvm.compiler.asm.sparc.SPARCAssembler.CC.Xcc;
31 import static org.graalvm.compiler.asm.sparc.SPARCAssembler.ConditionFlag.Equal;
32 import static org.graalvm.compiler.asm.sparc.SPARCAssembler.ConditionFlag.Less;
33 import static org.graalvm.compiler.asm.sparc.SPARCAssembler.ConditionFlag.NotEqual;
34 import static org.graalvm.compiler.lir.LIRInstruction.OperandFlag.REG;
35 import static jdk.vm.ci.code.ValueUtil.asRegister;
36 import static jdk.vm.ci.sparc.SPARC.g0;
37 import static jdk.vm.ci.sparc.SPARCKind.WORD;
38
39 import java.lang.reflect.Array;
40 import java.lang.reflect.Field;
41
42 import org.graalvm.compiler.asm.Label;
43 import org.graalvm.compiler.asm.sparc.SPARCAddress;
44 import org.graalvm.compiler.asm.sparc.SPARCMacroAssembler;
45 import org.graalvm.compiler.core.common.LIRKind;
46 import org.graalvm.compiler.lir.LIRInstructionClass;
47 import org.graalvm.compiler.lir.Opcode;
48 import org.graalvm.compiler.lir.asm.CompilationResultBuilder;
49 import org.graalvm.compiler.lir.gen.LIRGeneratorTool;
50
51 import jdk.vm.ci.code.Register;
52 import jdk.vm.ci.meta.JavaKind;
53 import jdk.vm.ci.meta.Value;
54 import jdk.vm.ci.sparc.SPARCKind;
55 import sun.misc.Unsafe;
56
57 /**
58 * Emits code which compares two arrays of the same length.
59 */
60 @Opcode("ARRAY_EQUALS")
61 public final class SPARCArrayEqualsOp extends SPARCLIRInstruction {
62 public static final LIRInstructionClass<SPARCArrayEqualsOp> TYPE = LIRInstructionClass.create(SPARCArrayEqualsOp.class);
63 public static final SizeEstimate SIZE = SizeEstimate.create(32);
64
65 private final JavaKind kind;
66 private final int arrayBaseOffset;
67 private final int arrayIndexScale;
68
69 @Def({REG}) protected Value resultValue;
70 @Alive({REG}) protected Value array1Value;
71 @Alive({REG}) protected Value array2Value;
72 @Alive({REG}) protected Value lengthValue;
73 @Temp({REG}) protected Value temp1;
74 @Temp({REG}) protected Value temp2;
75 @Temp({REG}) protected Value temp3;
76 @Temp({REG}) protected Value temp4;
77 @Temp({REG}) protected Value temp5;
78
79 public SPARCArrayEqualsOp(LIRGeneratorTool tool, JavaKind kind, Value result, Value array1, Value array2, Value length) {
80 super(TYPE, SIZE);
81 this.kind = kind;
82
83 Class<?> arrayClass = Array.newInstance(kind.toJavaClass(), 0).getClass();
84 this.arrayBaseOffset = UNSAFE.arrayBaseOffset(arrayClass);
85 this.arrayIndexScale = UNSAFE.arrayIndexScale(arrayClass);
86
87 this.resultValue = result;
88 this.array1Value = array1;
89 this.array2Value = array2;
90 this.lengthValue = length;
91
92 // Allocate some temporaries.
93 this.temp1 = tool.newVariable(LIRKind.unknownReference(tool.target().arch.getWordKind()));
94 this.temp2 = tool.newVariable(LIRKind.unknownReference(tool.target().arch.getWordKind()));
95 this.temp3 = tool.newVariable(LIRKind.value(tool.target().arch.getWordKind()));
96 this.temp4 = tool.newVariable(LIRKind.value(tool.target().arch.getWordKind()));
97 this.temp5 = tool.newVariable(LIRKind.value(tool.target().arch.getWordKind()));
98 }
99
100 @Override
101 public void emitCode(CompilationResultBuilder crb, SPARCMacroAssembler masm) {
102 Register result = asRegister(resultValue);
103 Register array1 = asRegister(temp1);
104 Register array2 = asRegister(temp2);
105 Register length = asRegister(temp3);
106
107 Label trueLabel = new Label();
108 Label falseLabel = new Label();
109 Label done = new Label();
110
111 // Load array base addresses.
112 masm.add(asRegister(array1Value), arrayBaseOffset, array1);
113 masm.add(asRegister(array2Value), arrayBaseOffset, array2);
114
115 // Get array length in bytes.
116 masm.mulx(asRegister(lengthValue, WORD), arrayIndexScale, length);
117 masm.mov(length, result); // copy
118
119 emit8ByteCompare(masm, result, array1, array2, length, trueLabel, falseLabel);
120 emitTailCompares(masm, result, array1, array2, trueLabel, falseLabel);
121
122 // Return true
123 masm.bind(trueLabel);
124 masm.mov(1, result);
125 masm.jmp(done);
126
127 // Return false
128 masm.bind(falseLabel);
129 masm.mov(g0, result);
130
131 // That's it
132 masm.bind(done);
133 }
134
135 /**
136 * Vector size used in {@link #emit8ByteCompare}.
137 */
138 private static final int VECTOR_SIZE = 8;
139
140 /**
141 * Emits code that uses 8-byte vector compares.
142 */
143 private void emit8ByteCompare(SPARCMacroAssembler masm, Register result, Register array1, Register array2, Register length, Label trueLabel, Label falseLabel) {
144 assert lengthValue.getPlatformKind().equals(SPARCKind.WORD);
145 Label loop = new Label();
146 Label compareTail = new Label();
147 Label compareTailCorrectVectorEnd = new Label();
148
149 Register tempReg1 = asRegister(temp4);
150 Register tempReg2 = asRegister(temp5);
151
152 masm.sra(length, 0, length);
153 masm.and(result, VECTOR_SIZE - 1, result); // tail count (in bytes)
154 masm.andcc(length, ~(VECTOR_SIZE - 1), length); // vector count (in bytes)
155 BPCC.emit(masm, Xcc, Equal, NOT_ANNUL, PREDICT_NOT_TAKEN, compareTail);
156
157 masm.sub(length, VECTOR_SIZE, length); // Delay slot
158 masm.add(array1, length, array1);
159 masm.add(array2, length, array2);
160 masm.sub(g0, length, length);
161
162 // Compare the last element first
163 masm.ldx(new SPARCAddress(array1, 0), tempReg1);
164 masm.ldx(new SPARCAddress(array2, 0), tempReg2);
165 masm.compareBranch(tempReg1, tempReg2, NotEqual, Xcc, falseLabel, PREDICT_NOT_TAKEN, null);
166 masm.compareBranch(length, 0, Equal, Xcc, compareTailCorrectVectorEnd, PREDICT_NOT_TAKEN, null);
167
168 // Load the first value from array 1 (Later done in back branch delay-slot)
169 masm.ldx(new SPARCAddress(array1, length), tempReg1);
170 masm.bind(loop);
171 masm.ldx(new SPARCAddress(array2, length), tempReg2);
172 masm.cmp(tempReg1, tempReg2);
173
174 BPCC.emit(masm, Xcc, NotEqual, NOT_ANNUL, PREDICT_NOT_TAKEN, falseLabel);
175 // Delay slot, not annul, add for next iteration
176 masm.addcc(length, VECTOR_SIZE, length);
177 // Annul, to prevent access past the array
178 BPCC.emit(masm, Xcc, NotEqual, ANNUL, PREDICT_TAKEN, loop);
179 masm.ldx(new SPARCAddress(array1, length), tempReg1); // Load in delay slot
180
181 // Tail count zero, therefore we can go to the end
182 masm.compareBranch(result, 0, Equal, Xcc, trueLabel, PREDICT_TAKEN, null);
183
184 masm.bind(compareTailCorrectVectorEnd);
185 // Correct the array pointers
186 masm.add(array1, VECTOR_SIZE, array1);
187 masm.add(array2, VECTOR_SIZE, array2);
188
189 masm.bind(compareTail);
190 }
191
192 /**
193 * Emits code to compare the remaining 1 to 4 bytes.
194 */
195 private void emitTailCompares(SPARCMacroAssembler masm, Register result, Register array1, Register array2, Label trueLabel, Label falseLabel) {
196 Label compare2Bytes = new Label();
197 Label compare1Byte = new Label();
198
199 Register tempReg1 = asRegister(temp3);
200 Register tempReg2 = asRegister(temp4);
201
202 if (kind.getByteCount() <= 4) {
203 // Compare trailing 4 bytes, if any.
204 masm.compareBranch(result, 4, Less, Xcc, compare2Bytes, PREDICT_NOT_TAKEN, null);
205
206 masm.lduw(new SPARCAddress(array1, 0), tempReg1);
207 masm.lduw(new SPARCAddress(array2, 0), tempReg2);
208 masm.compareBranch(tempReg1, tempReg2, NotEqual, Xcc, falseLabel, PREDICT_NOT_TAKEN, null);
209
210 if (kind.getByteCount() <= 2) {
211 // Move array pointers forward.
212 masm.add(array1, 4, array1);
213 masm.add(array2, 4, array2);
214 masm.sub(result, 4, result);
215
216 // Compare trailing 2 bytes, if any.
217 masm.bind(compare2Bytes);
218
219 masm.compareBranch(result, 2, Less, Xcc, compare1Byte, PREDICT_TAKEN, null);
220
221 masm.lduh(new SPARCAddress(array1, 0), tempReg1);
222 masm.lduh(new SPARCAddress(array2, 0), tempReg2);
223
224 masm.compareBranch(tempReg1, tempReg2, NotEqual, Xcc, falseLabel, PREDICT_TAKEN, null);
225
226 // The one-byte tail compare is only required for boolean and byte arrays.
227 if (kind.getByteCount() <= 1) {
228 // Move array pointers forward before we compare the last trailing byte.
229 masm.add(array1, 2, array1);
230 masm.add(array2, 2, array2);
231 masm.sub(result, 2, result);
232
233 // Compare trailing byte, if any.
234 masm.bind(compare1Byte);
235 masm.compareBranch(result, 1, NotEqual, Xcc, trueLabel, PREDICT_TAKEN, null);
236
237 masm.ldub(new SPARCAddress(array1, 0), tempReg1);
238 masm.ldub(new SPARCAddress(array2, 0), tempReg2);
239 masm.compareBranch(tempReg1, tempReg2, NotEqual, Xcc, falseLabel, PREDICT_TAKEN, null);
240 } else {
241 masm.bind(compare1Byte);
242 }
243 } else {
244 masm.bind(compare2Bytes);
245 }
246 }
247 }
248
249 private static final Unsafe UNSAFE = initUnsafe();
250
251 private static Unsafe initUnsafe() {
252 try {
253 return Unsafe.getUnsafe();
254 } catch (SecurityException se) {
255 try {
256 Field theUnsafe = Unsafe.class.getDeclaredField("theUnsafe");
257 theUnsafe.setAccessible(true);
258 return (Unsafe) theUnsafe.get(Unsafe.class);
259 } catch (Exception e) {
260 throw new RuntimeException("exception while trying to get Unsafe", e);
261 }
262 }
263 }
264 }