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 *
30 * @run main/othervm -XX:CompileCommand=compileonly,compiler.rangechecks.PowerOf2SizedArraysChecks::test*
31 * -XX:-BackgroundCompilation
32 * compiler.rangechecks.PowerOf2SizedArraysChecks
33 */
34
35 package compiler.rangechecks;
36
37 import java.util.function.BiFunction;
38 import java.util.function.Function;
39
40 public class PowerOf2SizedArraysChecks {
41
42 static void check_result(String name, int x, int m, boolean expected, boolean res) {
43 if (expected != res) {
44 throw new RuntimeException("Bad result in " + name + " for x = " + x + " m = " + m + " expected " + expected + " got " + res);
45 }
46 }
47
48 static void helper(String name, BiFunction<Integer, int[], Boolean> test, int[] x_values, int[] m_values, boolean[][] expected) {
49 for (int i = 0; i < x_values.length; i++) {
50 int x = x_values[i];
51 for (int j = 0; j < m_values.length; j++) {
52 int m = m_values[j];
53 int[] array = new int[m];
54 boolean res = test.apply(x, array);
55 check_result(name, x, m, expected[i][j], res);
56 }
57 }
58 }
59
60 static void check_result(String name, int m, boolean expected, boolean res) {
61 if (expected != res) {
62 throw new RuntimeException("Bad result in " + name + " for m = " + m + " expected " + expected + " got " + res);
63 }
64 }
65
66 static void helper2(String name, Function<int[], Boolean> test, int[] m_values, boolean[] expected) {
67 for (int j = 0; j < m_values.length; j++) {
68 int m = m_values[j];
69 int[] array = new int[m];
70 boolean res = test.apply(array);
71 check_result(name, m, expected[j], res);
72 }
73 }
74
75 // ((x & m) u<= m) is always true
76 static boolean test1(int x, int[] array) {
77 int m = array.length;
78 if ((x & m) < 0 || (x & m) > m) {
79 return false;
80 }
81 return true;
82 }
83
84 // ((x & (m - 1)) u< m) iff (m > 0)
85 static boolean test2(int x, int[] array) {
86 int m = array.length;
87 if ((x & (m-1)) < 0 || (x & (m-1)) >= m) {
88 return false;
89 }
90 return true;
91 }
92
93 static boolean test3(int x, int[] array) {
94 try {
95 int v = array[x & (array.length-1)];
96 } catch(ArrayIndexOutOfBoundsException aioobe) {
97 return false;
98 }
99 return true;
100 }
101
102 // arraylength <= 0 to arraylength u<= 0
103 static boolean test4(int[] array) {
104 if (array.length <= 0) {
105 return false;
106 }
107 return true;
108 }
109
110 // arraylength == 0 to arraylength u<= 0
111 static boolean test5(int[] array) {
112 if (array.length == 0) {
113 return false;
114 }
115 return true;
116 }
117
118 // arraylength != 0 to arraylength u> 0
119 static boolean test6(int[] array) {
120 if (array.length != 0) {
121 return false;
122 }
123 return true;
124 }
125
126 static public void main(String[] args) {
127 int[] x_values = {-10, -5, 0, 5, 8, 16, 100};
128 int[] m_values = { 16, 10, 0 };
129
130 boolean[][] test1_expected = new boolean[x_values.length][m_values.length];
131 for (int i = 0; i < x_values.length; i++) {
132 for (int j = 0; j < m_values.length; j++) {
133 test1_expected[i][j] = true;
134 }
135 }
136
137 boolean[][] test2_expected = new boolean[x_values.length][m_values.length];
138 for (int i = 0; i < x_values.length; i++) {
139 for (int j = 0; j < m_values.length; j++) {
140 test2_expected[i][j] = (m_values[j] > 0);
141 }
142 }
143
144 boolean[] test4_expected = new boolean[m_values.length];
145 for (int i = 0; i < m_values.length; i++) {
146 test4_expected[i] = (m_values[i] > 0);
147 }
148 boolean[] test5_expected = new boolean[m_values.length];
149 for (int i = 0; i < m_values.length; i++) {
150 test5_expected[i] = (m_values[i] != 0);
151 }
152 boolean[] test6_expected = new boolean[m_values.length];
153 for (int i = 0; i < m_values.length; i++) {
154 test6_expected[i] = (m_values[i] == 0);
155 }
156
157 for (int i = 0; i < 20000; i++) {
158 helper("test1", PowerOf2SizedArraysChecks::test1, x_values, m_values, test1_expected);
159 helper("test2", PowerOf2SizedArraysChecks::test2, x_values, m_values, test2_expected);
160 helper("test3", PowerOf2SizedArraysChecks::test3, x_values, m_values, test2_expected);
161 helper2("test4", PowerOf2SizedArraysChecks::test4, m_values, test4_expected);
162 helper2("test5", PowerOf2SizedArraysChecks::test5, m_values, test5_expected);
163 helper2("test6", PowerOf2SizedArraysChecks::test6, m_values, test6_expected);
164 }
165 }
166 }