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1 /*
2  * Copyright (c) 2003, 2011, 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  * @library ../Math
29  * @build DoubleConsts
30  * @run main ToHexString
31  * @author Joseph D. Darcy
32  */
33 
34 package test.java.lang.Double;
35 
36 import java.util.regex.*;
37 
38 import jdk.internal.math.DoubleConsts;
39 
40 public class ToHexString {
41     // Android-changed: JUnit expects exactly one public constructor.
42     // private ToHexString() {}
43 
44     /*
45      * Given a double value, create a hexadecimal floating-point
46      * string via an intermediate long hex string.
47      */
doubleToHexString(double d)48     static String doubleToHexString(double d) {
49         return hexLongStringtoHexDoubleString(Long.toHexString(Double.doubleToLongBits(d)));
50     }
51 
52     /*
53      * Transform the hexadecimal long output into the equivalent
54      * hexadecimal double value.
55      */
hexLongStringtoHexDoubleString(String transString)56     static String hexLongStringtoHexDoubleString(String transString) {
57         transString = transString.toLowerCase();
58 
59         String zeros = "";
60         StringBuffer result = new StringBuffer(24);
61 
62         for(int i = 0; i < (16 - transString.length()); i++, zeros += "0");
63         transString = zeros + transString;
64 
65         // assert transString.length == 16;
66 
67             char topChar;
68             // Extract sign
69             if((topChar=transString.charAt(0)) >= '8' ) {// 8, 9, a, A, b, B, ...
70                 result.append("-");
71                 // clear sign bit
72                 transString =
73                     Character.toString(Character.forDigit(Character.digit(topChar, 16) - 8, 16)) +
74                     transString.substring(1,16);
75             }
76 
77             // check for NaN and infinity
78             String signifString = transString.substring(3,16);
79 
80             if( transString.substring(0,3).equals("7ff") ) {
81                 if(signifString.equals("0000000000000")) {
82                     result.append("Infinity");
83                 }
84                 else
85                     result.append("NaN");
86             }
87             else { // finite value
88                 // Extract exponent
89                 int exponent = Integer.parseInt(transString.substring(0,3), 16) -
90                     DoubleConsts.EXP_BIAS;
91                 result.append("0x");
92 
93                 if (exponent == Double.MIN_EXPONENT - 1) { // zero or subnormal
94                     if(signifString.equals("0000000000000")) {
95                         result.append("0.0p0");
96                     }
97                     else {
98                         result.append("0." + signifString.replaceFirst("0+$", "").replaceFirst("^$", "0") +
99                                       "p-1022");
100                     }
101                 }
102                 else {  // normal value
103                     result.append("1." + signifString.replaceFirst("0+$", "").replaceFirst("^$", "0") +
104                                   "p" + exponent);
105                 }
106             }
107             return result.toString();
108     }
109 
toHexStringTests()110     public static int toHexStringTests() {
111         int failures = 0;
112         String [][] testCases1 = {
113             {"Infinity",                "Infinity"},
114             {"-Infinity",               "-Infinity"},
115             {"NaN",                     "NaN"},
116             {"-NaN",                    "NaN"},
117             {"0.0",                     "0x0.0p0"},
118             {"-0.0",                    "-0x0.0p0"},
119             {"1.0",                     "0x1.0p0"},
120             {"-1.0",                    "-0x1.0p0"},
121             {"2.0",                     "0x1.0p1"},
122             {"3.0",                     "0x1.8p1"},
123             {"0.5",                     "0x1.0p-1"},
124             {"0.25",                    "0x1.0p-2"},
125             {"1.7976931348623157e+308", "0x1.fffffffffffffp1023"},      // MAX_VALUE
126             {"2.2250738585072014E-308", "0x1.0p-1022"},                 // MIN_NORMAL
127             {"2.225073858507201E-308",  "0x0.fffffffffffffp-1022"},     // MAX_SUBNORMAL
128             {"4.9e-324",                "0x0.0000000000001p-1022"}      // MIN_VALUE
129         };
130 
131         // Compare decimal string -> double -> hex string to hex string
132         for (int i = 0; i < testCases1.length; i++) {
133             String result;
134             if(! (result=Double.toHexString(Double.parseDouble(testCases1[i][0]))).
135                equals(testCases1[i][1])) {
136                 failures ++;
137                 System.err.println("For floating-point string " + testCases1[i][0] +
138                                    ", expected hex output " + testCases1[i][1] + ", got " + result +".");
139             }
140         }
141 
142 
143         // Except for float subnormals, the output for numerically
144         // equal float and double values should be the same.
145         // Therefore, we will explicitly test float subnormal values.
146         String [][] floatTestCases = {
147             {"Infinity",                "Infinity"},
148             {"-Infinity",               "-Infinity"},
149             {"NaN",                     "NaN"},
150             {"-NaN",                    "NaN"},
151             {"0.0",                     "0x0.0p0"},
152             {"-0.0",                    "-0x0.0p0"},
153             {"1.0",                     "0x1.0p0"},
154             {"-1.0",                    "-0x1.0p0"},
155             {"2.0",                     "0x1.0p1"},
156             {"3.0",                     "0x1.8p1"},
157             {"0.5",                     "0x1.0p-1"},
158             {"0.25",                    "0x1.0p-2"},
159             {"3.4028235e+38f",          "0x1.fffffep127"},      // MAX_VALUE
160             {"1.17549435E-38f",         "0x1.0p-126"},          // MIN_NORMAL
161             {"1.1754942E-38",           "0x0.fffffep-126"},     // MAX_SUBNORMAL
162             {"1.4e-45f",                "0x0.000002p-126"}      // MIN_VALUE
163         };
164         // Compare decimal string -> double -> hex string to hex string
165         for (int i = 0; i < floatTestCases.length; i++) {
166             String result;
167             if(! (result=Float.toHexString(Float.parseFloat(floatTestCases[i][0]))).
168                equals(floatTestCases[i][1])) {
169                 failures++;
170                 System.err.println("For floating-point string " + floatTestCases[i][0] +
171                                    ", expected hex output\n" + floatTestCases[i][1] + ", got\n" + result +".");
172             }
173         }
174 
175         // Particular floating-point values and hex equivalents, mostly
176         // taken from fdlibm source.
177         String [][] testCases2 = {
178             {"+0.0",                                    "0000000000000000"},
179             {"-0.0",                                    "8000000000000000"},
180             {"+4.9e-324",                               "0000000000000001"},
181             {"-4.9e-324",                               "8000000000000001"},
182 
183             // fdlibm k_sin.c
184             {"+5.00000000000000000000e-01",             "3FE0000000000000"},
185             {"-1.66666666666666324348e-01",             "BFC5555555555549"},
186             {"+8.33333333332248946124e-03",             "3F8111111110F8A6"},
187             {"-1.98412698298579493134e-04",             "BF2A01A019C161D5"},
188             {"+2.75573137070700676789e-06",             "3EC71DE357B1FE7D"},
189             {"-2.50507602534068634195e-08",             "BE5AE5E68A2B9CEB"},
190             {"+1.58969099521155010221e-10",             "3DE5D93A5ACFD57C"},
191 
192             // fdlibm k_cos.c
193             {"+4.16666666666666019037e-02",             "3FA555555555554C"},
194             {"-1.38888888888741095749e-03",             "BF56C16C16C15177"},
195             {"+2.48015872894767294178e-05",             "3EFA01A019CB1590"},
196             {"-2.75573143513906633035e-07",             "BE927E4F809C52AD"},
197             {"+2.08757232129817482790e-09",             "3E21EE9EBDB4B1C4"},
198             {"-1.13596475577881948265e-11",             "BDA8FAE9BE8838D4"},
199 
200             // fdlibm e_rempio.c
201             {"1.67772160000000000000e+07",              "4170000000000000"},
202             {"6.36619772367581382433e-01",              "3FE45F306DC9C883"},
203             {"1.57079632673412561417e+00",              "3FF921FB54400000"},
204             {"6.07710050650619224932e-11",              "3DD0B4611A626331"},
205             {"6.07710050630396597660e-11",              "3DD0B4611A600000"},
206             {"2.02226624879595063154e-21",              "3BA3198A2E037073"},
207             {"2.02226624871116645580e-21",              "3BA3198A2E000000"},
208             {"8.47842766036889956997e-32",              "397B839A252049C1"},
209 
210 
211             // fdlibm s_cbrt.c
212             {"+5.42857142857142815906e-01",             "3FE15F15F15F15F1"},
213             {"-7.05306122448979611050e-01",             "BFE691DE2532C834"},
214             {"+1.41428571428571436819e+00",             "3FF6A0EA0EA0EA0F"},
215             {"+1.60714285714285720630e+00",             "3FF9B6DB6DB6DB6E"},
216             {"+3.57142857142857150787e-01",             "3FD6DB6DB6DB6DB7"},
217         };
218 
219         // Compare decimal string -> double -> hex string to
220         // long hex string -> double hex string
221         for (int i = 0; i < testCases2.length; i++) {
222             String result;
223             String expected;
224             if(! (result=Double.toHexString(Double.parseDouble(testCases2[i][0]))).
225                equals( expected=hexLongStringtoHexDoubleString(testCases2[i][1]) )) {
226                 failures ++;
227                 System.err.println("For floating-point string " + testCases2[i][0] +
228                                    ", expected hex output " + expected + ", got " + result +".");
229             }
230         }
231 
232         // Test random double values;
233         // compare double -> Double.toHexString with local doubleToHexString
234         java.util.Random rand = new java.util.Random(0);
235         for (int i = 0; i < 1000; i++) {
236             String result;
237             String expected;
238             double d = rand.nextDouble();
239             if(! (expected=doubleToHexString(d)).equals(result=Double.toHexString(d)) ) {
240                 failures ++;
241                 System.err.println("For floating-point value " + d +
242                                    ", expected hex output " + expected + ", got " + result +".");
243             }
244         }
245 
246         return failures;
247     }
248 
main(String argv[])249     public static void main(String argv[]) {
250         int failures = 0;
251 
252         failures = toHexStringTests();
253 
254         if (failures != 0) {
255             throw new RuntimeException("" + failures + " failures while testing Double.toHexString");
256         }
257     }
258 }
259