1 /*
2 * Copyright (c) 2003, 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 * @test
26 * @bug 4826774 4926547
27 * @summary Tests for {Float, Double}.toHexString methods
28 * @author Joseph D. Darcy
29 */
30
31 import java.util.regex.*;
32 import sun.misc.DoubleConsts;
33
34 public class ToHexString {
35 private ToHexString() {}
36
37 /*
38 * Given a double value, create a hexadecimal floating-point
39 * string via an intermediate long hex string.
40 */
41 static String doubleToHexString(double d) {
42 return hexLongStringtoHexDoubleString(Long.toHexString(Double.doubleToLongBits(d)));
43 }
44
45 /*
46 * Transform the hexadecimal long output into the equivalent
47 * hexadecimal double value.
48 */
49 static String hexLongStringtoHexDoubleString(String transString) {
50 transString = transString.toLowerCase();
51
52 String zeros = "";
53 StringBuffer result = new StringBuffer(24);
54
55 for(int i = 0; i < (16 - transString.length()); i++, zeros += "0");
56 transString = zeros + transString;
57
58 // assert transString.length == 16;
59
60 char topChar;
61 // Extract sign
62 if((topChar=transString.charAt(0)) >= '8' ) {// 8, 9, a, A, b, B, ...
63 result.append("-");
64 // clear sign bit
65 transString =
66 Character.toString(Character.forDigit(Character.digit(topChar, 16) - 8, 16)) +
67 transString.substring(1,16);
68 }
69
70 // check for NaN and infinity
71 String signifString = transString.substring(3,16);
72
73 if( transString.substring(0,3).equals("7ff") ) {
74 if(signifString.equals("0000000000000")) {
75 result.append("Infinity");
76 }
77 else
78 result.append("NaN");
79 }
80 else { // finite value
81 // Extract exponent
82 int exponent = Integer.parseInt(transString.substring(0,3), 16) -
83 DoubleConsts.EXP_BIAS;
84 result.append("0x");
85
86 if (exponent == DoubleConsts.MIN_EXPONENT - 1) { // zero or subnormal
87 if(signifString.equals("0000000000000")) {
88 result.append("0.0p0");
89 }
90 else {
91 result.append("0." + signifString.replaceFirst("0+$", "").replaceFirst("^$", "0") +
92 "p-1022");
93 }
94 }
95 else { // normal value
96 result.append("1." + signifString.replaceFirst("0+$", "").replaceFirst("^$", "0") +
97 "p" + exponent);
98 }
99 }
100 return result.toString();
101 }
102
103 public static int toHexStringTests() {
104 int failures = 0;
105 String [][] testCases1 = {
106 {"Infinity", "Infinity"},
107 {"-Infinity", "-Infinity"},
108 {"NaN", "NaN"},
109 {"-NaN", "NaN"},
110 {"0.0", "0x0.0p0"},
111 {"-0.0", "-0x0.0p0"},
112 {"1.0", "0x1.0p0"},
113 {"-1.0", "-0x1.0p0"},
114 {"2.0", "0x1.0p1"},
115 {"3.0", "0x1.8p1"},
116 {"0.5", "0x1.0p-1"},
117 {"0.25", "0x1.0p-2"},
118 {"1.7976931348623157e+308", "0x1.fffffffffffffp1023"}, // MAX_VALUE
119 {"2.2250738585072014E-308", "0x1.0p-1022"}, // MIN_NORMAL
120 {"2.225073858507201E-308", "0x0.fffffffffffffp-1022"}, // MAX_SUBNORMAL
121 {"4.9e-324", "0x0.0000000000001p-1022"} // MIN_VALUE
122 };
123
124 // Compare decimal string -> double -> hex string to hex string
125 for (int i = 0; i < testCases1.length; i++) {
126 String result;
127 if(! (result=Double.toHexString(Double.parseDouble(testCases1[i][0]))).
128 equals(testCases1[i][1])) {
129 failures ++;
130 System.err.println("For floating-point string " + testCases1[i][0] +
131 ", expected hex output " + testCases1[i][1] + ", got " + result +".");
132 }
133 }
134
135
136 // Except for float subnormals, the output for numerically
137 // equal float and double values should be the same.
138 // Therefore, we will explicitly test float subnormal values.
139 String [][] floatTestCases = {
140 {"Infinity", "Infinity"},
141 {"-Infinity", "-Infinity"},
142 {"NaN", "NaN"},
143 {"-NaN", "NaN"},
144 {"0.0", "0x0.0p0"},
145 {"-0.0", "-0x0.0p0"},
146 {"1.0", "0x1.0p0"},
147 {"-1.0", "-0x1.0p0"},
148 {"2.0", "0x1.0p1"},
149 {"3.0", "0x1.8p1"},
150 {"0.5", "0x1.0p-1"},
151 {"0.25", "0x1.0p-2"},
152 {"3.4028235e+38f", "0x1.fffffep127"}, // MAX_VALUE
153 {"1.17549435E-38f", "0x1.0p-126"}, // MIN_NORMAL
154 {"1.1754942E-38", "0x0.fffffep-126"}, // MAX_SUBNORMAL
155 {"1.4e-45f", "0x0.000002p-126"} // MIN_VALUE
156 };
157 // Compare decimal string -> double -> hex string to hex string
158 for (int i = 0; i < floatTestCases.length; i++) {
159 String result;
160 if(! (result=Float.toHexString(Float.parseFloat(floatTestCases[i][0]))).
161 equals(floatTestCases[i][1])) {
162 failures++;
163 System.err.println("For floating-point string " + floatTestCases[i][0] +
164 ", expected hex output\n" + floatTestCases[i][1] + ", got\n" + result +".");
165 }
166 }
167
168 // Particular floating-point values and hex equivalents, mostly
169 // taken from fdlibm source.
170 String [][] testCases2 = {
171 {"+0.0", "0000000000000000"},
172 {"-0.0", "8000000000000000"},
173 {"+4.9e-324", "0000000000000001"},
174 {"-4.9e-324", "8000000000000001"},
175
176 // fdlibm k_sin.c
177 {"+5.00000000000000000000e-01", "3FE0000000000000"},
178 {"-1.66666666666666324348e-01", "BFC5555555555549"},
179 {"+8.33333333332248946124e-03", "3F8111111110F8A6"},
180 {"-1.98412698298579493134e-04", "BF2A01A019C161D5"},
181 {"+2.75573137070700676789e-06", "3EC71DE357B1FE7D"},
182 {"-2.50507602534068634195e-08", "BE5AE5E68A2B9CEB"},
183 {"+1.58969099521155010221e-10", "3DE5D93A5ACFD57C"},
184
185 // fdlibm k_cos.c
186 {"+4.16666666666666019037e-02", "3FA555555555554C"},
187 {"-1.38888888888741095749e-03", "BF56C16C16C15177"},
188 {"+2.48015872894767294178e-05", "3EFA01A019CB1590"},
189 {"-2.75573143513906633035e-07", "BE927E4F809C52AD"},
190 {"+2.08757232129817482790e-09", "3E21EE9EBDB4B1C4"},
191 {"-1.13596475577881948265e-11", "BDA8FAE9BE8838D4"},
192
193 // fdlibm e_rempio.c
194 {"1.67772160000000000000e+07", "4170000000000000"},
195 {"6.36619772367581382433e-01", "3FE45F306DC9C883"},
196 {"1.57079632673412561417e+00", "3FF921FB54400000"},
197 {"6.07710050650619224932e-11", "3DD0B4611A626331"},
198 {"6.07710050630396597660e-11", "3DD0B4611A600000"},
199 {"2.02226624879595063154e-21", "3BA3198A2E037073"},
200 {"2.02226624871116645580e-21", "3BA3198A2E000000"},
201 {"8.47842766036889956997e-32", "397B839A252049C1"},
202
203
204 // fdlibm s_cbrt.c
205 {"+5.42857142857142815906e-01", "3FE15F15F15F15F1"},
206 {"-7.05306122448979611050e-01", "BFE691DE2532C834"},
207 {"+1.41428571428571436819e+00", "3FF6A0EA0EA0EA0F"},
208 {"+1.60714285714285720630e+00", "3FF9B6DB6DB6DB6E"},
209 {"+3.57142857142857150787e-01", "3FD6DB6DB6DB6DB7"},
210 };
211
212 // Compare decimal string -> double -> hex string to
213 // long hex string -> double hex string
214 for (int i = 0; i < testCases2.length; i++) {
215 String result;
216 String expected;
217 if(! (result=Double.toHexString(Double.parseDouble(testCases2[i][0]))).
218 equals( expected=hexLongStringtoHexDoubleString(testCases2[i][1]) )) {
219 failures ++;
220 System.err.println("For floating-point string " + testCases2[i][0] +
221 ", expected hex output " + expected + ", got " + result +".");
222 }
223 }
224
225 // Test random double values;
226 // compare double -> Double.toHexString with local doubleToHexString
227 java.util.Random rand = new java.util.Random(0);
228 for (int i = 0; i < 1000; i++) {
229 String result;
230 String expected;
231 double d = rand.nextDouble();
232 if(! (expected=doubleToHexString(d)).equals(result=Double.toHexString(d)) ) {
233 failures ++;
234 System.err.println("For floating-point value " + d +
235 ", expected hex output " + expected + ", got " + result +".");
236 }
237 }
238
239 return failures;
240 }
241
242 public static void main(String argv[]) {
243 int failures = 0;
244
245 failures = toHexStringTests();
246
247 if (failures != 0) {
248 throw new RuntimeException("" + failures + " failures while testing Double.toHexString");
249 }
250 }
251 }