1 /*
2 * Copyright (c) 2015, 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 */
24
25 /**
26 * @test
27 * @bug 8003585
28 * @summary strength reduce or eliminate range checks for power-of-two sized arrays
29 * @run main/othervm -XX:CompileCommand=compileonly,PowerOf2SizedArraysChecks::test* -XX:-BackgroundCompilation PowerOf2SizedArraysChecks
30 *
31 */
32
33 import java.util.function.*;
34
35 public class PowerOf2SizedArraysChecks {
36
37 static void check_result(String name, int x, int m, boolean expected, boolean res) {
38 if (expected != res) {
39 throw new RuntimeException("Bad result in " + name + " for x = " + x + " m = " + m + " expected " + expected + " got " + res);
40 }
41 }
42
43 static void helper(String name, BiFunction<Integer, int[], Boolean> test, int[] x_values, int[] m_values, boolean[][] expected) {
44 for (int i = 0; i < x_values.length; i++) {
45 int x = x_values[i];
46 for (int j = 0; j < m_values.length; j++) {
47 int m = m_values[j];
48 int[] array = new int[m];
49 boolean res = test.apply(x, array);
50 check_result(name, x, m, expected[i][j], res);
51 }
52 }
53 }
54
55 static void check_result(String name, int m, boolean expected, boolean res) {
56 if (expected != res) {
57 throw new RuntimeException("Bad result in " + name + " for m = " + m + " expected " + expected + " got " + res);
58 }
59 }
60
61 static void helper2(String name, Function<int[], Boolean> test, int[] m_values, boolean[] expected) {
62 for (int j = 0; j < m_values.length; j++) {
63 int m = m_values[j];
64 int[] array = new int[m];
65 boolean res = test.apply(array);
66 check_result(name, m, expected[j], res);
67 }
68 }
69
70 // ((x & m) u<= m) is always true
71 static boolean test1(int x, int[] array) {
72 int m = array.length;
73 if ((x & m) < 0 || (x & m) > m) {
74 return false;
75 }
76 return true;
77 }
78
79 // ((x & (m - 1)) u< m) iff (m > 0)
80 static boolean test2(int x, int[] array) {
81 int m = array.length;
82 if ((x & (m-1)) < 0 || (x & (m-1)) >= m) {
83 return false;
84 }
85 return true;
86 }
87
88 static boolean test3(int x, int[] array) {
89 try {
90 int v = array[x & (array.length-1)];
91 } catch(ArrayIndexOutOfBoundsException aioobe) {
92 return false;
93 }
94 return true;
95 }
96
97 // arraylength <= 0 to arraylength u<= 0
98 static boolean test4(int[] array) {
99 if (array.length <= 0) {
100 return false;
101 }
102 return true;
103 }
104
105 // arraylength == 0 to arraylength u<= 0
106 static boolean test5(int[] array) {
107 if (array.length == 0) {
108 return false;
109 }
110 return true;
111 }
112
113 // arraylength != 0 to arraylength u> 0
114 static boolean test6(int[] array) {
115 if (array.length != 0) {
116 return false;
117 }
118 return true;
119 }
120
121 static public void main(String[] args) {
122 int[] x_values = {-10, -5, 0, 5, 8, 16, 100};
123 int[] m_values = { 16, 10, 0 };
124
125 boolean[][] test1_expected = new boolean[x_values.length][m_values.length];
126 for (int i = 0; i < x_values.length; i++) {
127 for (int j = 0; j < m_values.length; j++) {
128 test1_expected[i][j] = true;
129 }
130 }
131
132 boolean[][] test2_expected = new boolean[x_values.length][m_values.length];
133 for (int i = 0; i < x_values.length; i++) {
134 for (int j = 0; j < m_values.length; j++) {
135 test2_expected[i][j] = (m_values[j] > 0);
136 }
137 }
138
139 boolean[] test4_expected = new boolean[m_values.length];
140 for (int i = 0; i < m_values.length; i++) {
141 test4_expected[i] = (m_values[i] > 0);
142 }
143 boolean[] test5_expected = new boolean[m_values.length];
144 for (int i = 0; i < m_values.length; i++) {
145 test5_expected[i] = (m_values[i] != 0);
146 }
147 boolean[] test6_expected = new boolean[m_values.length];
148 for (int i = 0; i < m_values.length; i++) {
149 test6_expected[i] = (m_values[i] == 0);
150 }
151
152 for (int i = 0; i < 20000; i++) {
153 helper("test1", PowerOf2SizedArraysChecks::test1, x_values, m_values, test1_expected);
154 helper("test2", PowerOf2SizedArraysChecks::test2, x_values, m_values, test2_expected);
155 helper("test3", PowerOf2SizedArraysChecks::test3, x_values, m_values, test2_expected);
156 helper2("test4", PowerOf2SizedArraysChecks::test4, m_values, test4_expected);
157 helper2("test5", PowerOf2SizedArraysChecks::test5, m_values, test5_expected);
158 helper2("test6", PowerOf2SizedArraysChecks::test6, m_values, test6_expected);
159 }
160 }
161 }