1 /* 2 * Copyright (c) 2015, Red Hat, Inc. 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 * @test 26 * @bug 8144028 27 * @summary Use AArch64 bit-test instructions in C2 28 * 29 * @run main/othervm -Xbatch -XX:-TieredCompilation 30 * -XX:CompileCommand=dontinline,compiler.codegen.BitTests::* 31 * compiler.codegen.BitTests 32 * @run main/othervm -Xbatch -XX:+TieredCompilation -XX:TieredStopAtLevel=1 33 * compiler.codegen.BitTests 34 * @run main/othervm -Xbatch -XX:+TieredCompilation 35 * compiler.codegen.BitTests 36 */ 37 38 package compiler.codegen; 39 40 // Try to ensure that the bit test instructions TBZ/TBNZ, TST/TSTW 41 // don't generate incorrect code. We can't guarantee that C2 will use 42 // bit test instructions for this test and it's not a bug if it 43 // doesn't. However, these test cases are ideal candidates for each 44 // of the instruction forms. 45 public class BitTests { 46 47 private final XorShift r = new XorShift(); 48 increment(long ctr)49 private final long increment(long ctr) { 50 return ctr + 1; 51 } 52 increment(int ctr)53 private final int increment(int ctr) { 54 return ctr + 1; 55 } 56 testIntSignedBranch(long counter)57 private final long testIntSignedBranch(long counter) { 58 if ((int) r.nextLong() < 0) { 59 counter = increment(counter); 60 } 61 return counter; 62 } 63 testLongSignedBranch(long counter)64 private final long testLongSignedBranch(long counter) { 65 if (r.nextLong() < 0) { 66 counter = increment(counter); 67 } 68 return counter; 69 } 70 testIntBitBranch(long counter)71 private final long testIntBitBranch(long counter) { 72 if (((int) r.nextLong() & (1 << 27)) != 0) { 73 counter = increment(counter); 74 } 75 if (((int) r.nextLong() & (1 << 27)) != 0) { 76 counter = increment(counter); 77 } 78 return counter; 79 } 80 testLongBitBranch(long counter)81 private final long testLongBitBranch(long counter) { 82 if ((r.nextLong() & (1l << 50)) != 0) { 83 counter = increment(counter); 84 } 85 if ((r.nextLong() & (1l << 50)) != 0) { 86 counter = increment(counter); 87 } 88 return counter; 89 } 90 testLongMaskBranch(long counter)91 private final long testLongMaskBranch(long counter) { 92 if (((r.nextLong() & 0x0800000000l) != 0)) { 93 counter++; 94 } 95 return counter; 96 } 97 testIntMaskBranch(long counter)98 private final long testIntMaskBranch(long counter) { 99 if ((((int) r.nextLong() & 0x08) != 0)) { 100 counter++; 101 } 102 return counter; 103 } 104 testLongMaskBranch(long counter, long mask)105 private final long testLongMaskBranch(long counter, long mask) { 106 if (((r.nextLong() & mask) != 0)) { 107 counter++; 108 } 109 return counter; 110 } 111 testIntMaskBranch(long counter, int mask)112 private final long testIntMaskBranch(long counter, int mask) { 113 if ((((int) r.nextLong() & mask) != 0)) { 114 counter++; 115 } 116 return counter; 117 } 118 step(long counter)119 private final long step(long counter) { 120 counter = testIntSignedBranch(counter); 121 counter = testLongSignedBranch(counter); 122 counter = testIntBitBranch(counter); 123 counter = testLongBitBranch(counter); 124 counter = testIntMaskBranch(counter); 125 counter = testLongMaskBranch(counter); 126 counter = testIntMaskBranch(counter, 0x8000); 127 counter = testLongMaskBranch(counter, 0x800000000l); 128 return counter; 129 } 130 131 132 private final long finalBits = 3; 133 134 private long bits = 7; 135 main(String[] args)136 public static void main(String[] args) { 137 BitTests t = new BitTests(); 138 139 long counter = 0; 140 for (int i = 0; i < 10000000; i++) { 141 counter = t.step((int) counter); 142 } 143 if (counter != 50001495) { 144 System.err.println("FAILED: counter = " + counter + ", should be 50001495."); 145 System.exit(97); 146 } 147 System.out.println("PASSED"); 148 } 149 150 // Marsaglia's xor-shift generator, used here because it is 151 // reproducible across all Java implementations. It is also very 152 // fast. 153 static class XorShift { 154 155 private long y; 156 XorShift()157 XorShift() { 158 y = 2463534242l; 159 } 160 nextLong()161 public long nextLong() { 162 y ^= (y << 13); 163 y ^= (y >>> 17); 164 return (y ^= (y << 5)); 165 166 } 167 } 168 } 169