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23
24 /**
25 * @test
26 * @bug 6603011
27 * @summary long/int division by constant
28 * @modules java.base/jdk.internal.misc
29 * @library /test/lib
30 *
31 * @run main/othervm -Xcomp -Xbatch -XX:-Inline compiler.c2.Test6603011
32 */
33
34 //
35 // -XX:-Inline is essential to this test so that verification functions
36 // divi, modi, divl and modl generate "plain" divides.
37 // -Xcomp -Xbatch are also useful to ensure the full range of
38 // dividend and divisor combinations are tested
39 //
40
41 package compiler.c2;
42
43 import jdk.test.lib.Utils;
44
45 public class Test6603011 implements Runnable {
46 static class s {
47 static int divi(int dividend, int divisor) { return dividend / divisor; }
48 static int modi(int dividend, int divisor) { return dividend % divisor; }
49 static long divl(long dividend, long divisor) { return dividend / divisor; }
50 static long modl(long dividend, long divisor) { return dividend % divisor; }
51 }
52 // Report verbose messages on failure; turn off to suppress
53 // too much output with gross numbers of failures.
54 static final boolean VERBOSE = true;
55
56 // Initailize DIVISOR so that it is final in this class.
57 static final int DIVISOR;
58 static {
59 int value = 0;
60 try {
61 value = Integer.decode(System.getProperty("divisor"));
62 } catch (Throwable e) {
63 }
64 DIVISOR = value;
65 }
66
67 // The methods of interest. We want the JIT to compile these
68 // and convert the divide into a multiply.
69 public int divbyI (int dividend) { return dividend / DIVISOR; }
70 public int modbyI (int dividend) { return dividend % DIVISOR; }
71 public long divbyL (long dividend) { return dividend / DIVISOR; }
72 public long modbyL (long dividend) { return dividend % DIVISOR; }
73
74 public int divisor() { return DIVISOR; }
75
76 public boolean checkI (int dividend) {
77 int quo = divbyI(dividend);
78 int rem = modbyI(dividend);
79 int quo0 = s.divi(dividend, divisor());
80 int rem0 = s.modi(dividend, divisor());
81
82 if (quo != quo0 || rem != rem0) {
83 if (VERBOSE) {
84 System.out.println("Computed: " + dividend + " / " + divisor() + " = " +
85 quo + ", " + dividend + " % " + divisor() + " = " + rem );
86 System.out.println("expected: " + dividend + " / " + divisor() + " = " +
87 quo0 + ", " + dividend + " % " + divisor() + " = " + rem0);
88 // Report sign of rem failure
89 if (rem != 0 && (rem ^ dividend) < 0) {
90 System.out.println(" rem & dividend have different signs");
91 }
92 // Report range of rem failure
93 if (java.lang.Math.abs(rem) >= java.lang.Math.abs(divisor())) {
94 System.out.println(" remainder out of range");
95 }
96 // Report quo/rem identity relationship failure
97 if ((quo * divisor()) + rem != dividend) {
98 System.out.println(" quotien/remainder invariant broken");
99 }
100 }
101 return false;
102 }
103 return true;
104 }
105
106 public boolean checkL (long dividend) {
107 long quo = divbyL(dividend);
108 long rem = modbyL(dividend);
109 long quo0 = s.divl(dividend, divisor());
110 long rem0 = s.modl(dividend, divisor());
111
112 if (quo != quo0 || rem != rem0) {
113 if (VERBOSE) {
114 System.out.println("Computed: " + dividend + " / " + divisor() + " = " +
115 quo + ", " + dividend + " % " + divisor() + " = " + rem );
116 System.out.println("expected: " + dividend + " / " + divisor() + " = " +
117 quo0 + ", " + dividend + " % " + divisor() + " = " + rem0);
118 // Report sign of rem failure
119 if (rem != 0 && (rem ^ dividend) < 0) {
120 System.out.println(" rem & dividend have different signs");
121 }
122 // Report range of rem failure
123 if (java.lang.Math.abs(rem) >= java.lang.Math.abs(divisor())) {
124 System.out.println(" remainder out of range");
125 }
126 // Report quo/rem identity relationship failure
127 if ((quo * divisor()) + rem != dividend) {
128 System.out.println(" (" + quo + " * " + divisor() + ") + " + rem + " != "
129 + dividend);
130 }
131 }
132 return false;
133 }
134 return true;
135 }
136
137 public void run() {
138 // Don't try to divide by zero
139 if (divisor() == 0) return;
140
141 // Range of dividends to check. Try dividends from start to end
142 // inclusive, as well as variations on those values as shifted
143 // left.
144 int start = -1024;
145 int end = 1024;
146
147 // Test int division using a variety of dividends.
148 int wrong = 0;
149 int total = 0;
150
151 outerloop:
152 for (int i = start; i <= end; i++) {
153 for (int s = 0; s < 32; s += 4) {
154 total++;
155 int dividend = i << s;
156 if (!checkI(dividend)) {
157 wrong++;
158 // Stop on the first failure
159 // break outerloop;
160 }
161 }
162 }
163 if (wrong > 0) {
164 System.out.println("divisor " + divisor() + ": " +
165 wrong + "/" + total + " wrong int divisions");
166 }
167
168 // Test long division using a variety of dividends.
169 wrong = 0;
170 total = 0;
171
172 outerloop:
173 for (int i = start; i <= end; i++) {
174 for (int s = 0; s < 64; s += 4) {
175 total++;
176 long dividend = ((long)i) << s;
177 if (!checkL(dividend)) {
178 wrong++;
179 // Stop on the first failure
180 // break outerloop;
181 }
182 }
183 }
184 if (wrong > 0) {
185 System.out.println("divisor " + divisor() + ": " +
186 wrong + "/" + total + " wrong long divisions");
187 }
188
189 }
190
191 // Reload this class with the "divisor" property set to the input parameter.
192 // This allows the JIT to see q.DIVISOR as a final constant, and change
193 // any divisions or mod operations into multiplies.
194 public static void test_divisor(int divisor,
195 ClassLoader apploader) throws Exception {
196 System.setProperty("divisor", "" + divisor);
197 ClassLoader loader
198 = Utils.getTestClassPathURLClassLoader(apploader.getParent());
199 Class c = loader.loadClass(Test6603011.class.getName());
200 Runnable r = (Runnable)c.newInstance();
201 r.run();
202 }
203
204 public static void main(String[] args) throws Exception {
205 Class cl = Test6603011.class;
206 ClassLoader apploader = cl.getClassLoader();
207
208
209 // Test every divisor between -100 and 100.
210 for (int i = -100; i <= 100; i++) {
211 test_divisor(i, apploader);
212 }
213
214 // Try a few divisors outside the typical range.
215 // The values below have been observed in rt.jar.
216 test_divisor(101, apploader);
217 test_divisor(400, apploader);
218 test_divisor(1000, apploader);
219 test_divisor(3600, apploader);
220 test_divisor(9973, apploader);
221 test_divisor(86400, apploader);
222 test_divisor(1000000, apploader);
223 }
224
225 }