1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
|
/*
* Copyright (c) 2003, 2011, Oracle and/or its affiliates. All rights reserved.
* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
*
* This code is free software; you can redistribute it and/or modify it
* under the terms of the GNU General Public License version 2 only, as
* published by the Free Software Foundation.
*
* This code is distributed in the hope that it will be useful, but WITHOUT
* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
* version 2 for more details (a copy is included in the LICENSE file that
* accompanied this code).
*
* You should have received a copy of the GNU General Public License version
* 2 along with this work; if not, write to the Free Software Foundation,
* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
*
* Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
* or visit www.oracle.com if you need additional information or have any
* questions.
*/
/*
* @test
* @bug 4826774 4926547
* @summary Tests for {Float, Double}.toHexString methods
* @library ../Math
* @build DoubleConsts
* @run main ToHexString
* @author Joseph D. Darcy
*/
import java.util.regex.*;
public class ToHexString {
private ToHexString() {}
/*
* Given a double value, create a hexadecimal floating-point
* string via an intermediate long hex string.
*/
static String doubleToHexString(double d) {
return hexLongStringtoHexDoubleString(Long.toHexString(Double.doubleToLongBits(d)));
}
/*
* Transform the hexadecimal long output into the equivalent
* hexadecimal double value.
*/
static String hexLongStringtoHexDoubleString(String transString) {
transString = transString.toLowerCase();
String zeros = "";
StringBuffer result = new StringBuffer(24);
for(int i = 0; i < (16 - transString.length()); i++, zeros += "0");
transString = zeros + transString;
// assert transString.length == 16;
char topChar;
// Extract sign
if((topChar=transString.charAt(0)) >= '8' ) {// 8, 9, a, A, b, B, ...
result.append("-");
// clear sign bit
transString =
Character.toString(Character.forDigit(Character.digit(topChar, 16) - 8, 16)) +
transString.substring(1,16);
}
// check for NaN and infinity
String signifString = transString.substring(3,16);
if( transString.substring(0,3).equals("7ff") ) {
if(signifString.equals("0000000000000")) {
result.append("Infinity");
}
else
result.append("NaN");
}
else { // finite value
// Extract exponent
int exponent = Integer.parseInt(transString.substring(0,3), 16) -
DoubleConsts.EXP_BIAS;
result.append("0x");
if (exponent == Double.MIN_EXPONENT - 1) { // zero or subnormal
if(signifString.equals("0000000000000")) {
result.append("0.0p0");
}
else {
result.append("0." + signifString.replaceFirst("0+$", "").replaceFirst("^$", "0") +
"p-1022");
}
}
else { // normal value
result.append("1." + signifString.replaceFirst("0+$", "").replaceFirst("^$", "0") +
"p" + exponent);
}
}
return result.toString();
}
public static int toHexStringTests() {
int failures = 0;
String [][] testCases1 = {
{"Infinity", "Infinity"},
{"-Infinity", "-Infinity"},
{"NaN", "NaN"},
{"-NaN", "NaN"},
{"0.0", "0x0.0p0"},
{"-0.0", "-0x0.0p0"},
{"1.0", "0x1.0p0"},
{"-1.0", "-0x1.0p0"},
{"2.0", "0x1.0p1"},
{"3.0", "0x1.8p1"},
{"0.5", "0x1.0p-1"},
{"0.25", "0x1.0p-2"},
{"1.7976931348623157e+308", "0x1.fffffffffffffp1023"}, // MAX_VALUE
{"2.2250738585072014E-308", "0x1.0p-1022"}, // MIN_NORMAL
{"2.225073858507201E-308", "0x0.fffffffffffffp-1022"}, // MAX_SUBNORMAL
{"4.9e-324", "0x0.0000000000001p-1022"} // MIN_VALUE
};
// Compare decimal string -> double -> hex string to hex string
for (int i = 0; i < testCases1.length; i++) {
String result;
if(! (result=Double.toHexString(Double.parseDouble(testCases1[i][0]))).
equals(testCases1[i][1])) {
failures ++;
System.err.println("For floating-point string " + testCases1[i][0] +
", expected hex output " + testCases1[i][1] + ", got " + result +".");
}
}
// Except for float subnormals, the output for numerically
// equal float and double values should be the same.
// Therefore, we will explicitly test float subnormal values.
String [][] floatTestCases = {
{"Infinity", "Infinity"},
{"-Infinity", "-Infinity"},
{"NaN", "NaN"},
{"-NaN", "NaN"},
{"0.0", "0x0.0p0"},
{"-0.0", "-0x0.0p0"},
{"1.0", "0x1.0p0"},
{"-1.0", "-0x1.0p0"},
{"2.0", "0x1.0p1"},
{"3.0", "0x1.8p1"},
{"0.5", "0x1.0p-1"},
{"0.25", "0x1.0p-2"},
{"3.4028235e+38f", "0x1.fffffep127"}, // MAX_VALUE
{"1.17549435E-38f", "0x1.0p-126"}, // MIN_NORMAL
{"1.1754942E-38", "0x0.fffffep-126"}, // MAX_SUBNORMAL
{"1.4e-45f", "0x0.000002p-126"} // MIN_VALUE
};
// Compare decimal string -> double -> hex string to hex string
for (int i = 0; i < floatTestCases.length; i++) {
String result;
if(! (result=Float.toHexString(Float.parseFloat(floatTestCases[i][0]))).
equals(floatTestCases[i][1])) {
failures++;
System.err.println("For floating-point string " + floatTestCases[i][0] +
", expected hex output\n" + floatTestCases[i][1] + ", got\n" + result +".");
}
}
// Particular floating-point values and hex equivalents, mostly
// taken from fdlibm source.
String [][] testCases2 = {
{"+0.0", "0000000000000000"},
{"-0.0", "8000000000000000"},
{"+4.9e-324", "0000000000000001"},
{"-4.9e-324", "8000000000000001"},
// fdlibm k_sin.c
{"+5.00000000000000000000e-01", "3FE0000000000000"},
{"-1.66666666666666324348e-01", "BFC5555555555549"},
{"+8.33333333332248946124e-03", "3F8111111110F8A6"},
{"-1.98412698298579493134e-04", "BF2A01A019C161D5"},
{"+2.75573137070700676789e-06", "3EC71DE357B1FE7D"},
{"-2.50507602534068634195e-08", "BE5AE5E68A2B9CEB"},
{"+1.58969099521155010221e-10", "3DE5D93A5ACFD57C"},
// fdlibm k_cos.c
{"+4.16666666666666019037e-02", "3FA555555555554C"},
{"-1.38888888888741095749e-03", "BF56C16C16C15177"},
{"+2.48015872894767294178e-05", "3EFA01A019CB1590"},
{"-2.75573143513906633035e-07", "BE927E4F809C52AD"},
{"+2.08757232129817482790e-09", "3E21EE9EBDB4B1C4"},
{"-1.13596475577881948265e-11", "BDA8FAE9BE8838D4"},
// fdlibm e_rempio.c
{"1.67772160000000000000e+07", "4170000000000000"},
{"6.36619772367581382433e-01", "3FE45F306DC9C883"},
{"1.57079632673412561417e+00", "3FF921FB54400000"},
{"6.07710050650619224932e-11", "3DD0B4611A626331"},
{"6.07710050630396597660e-11", "3DD0B4611A600000"},
{"2.02226624879595063154e-21", "3BA3198A2E037073"},
{"2.02226624871116645580e-21", "3BA3198A2E000000"},
{"8.47842766036889956997e-32", "397B839A252049C1"},
// fdlibm s_cbrt.c
{"+5.42857142857142815906e-01", "3FE15F15F15F15F1"},
{"-7.05306122448979611050e-01", "BFE691DE2532C834"},
{"+1.41428571428571436819e+00", "3FF6A0EA0EA0EA0F"},
{"+1.60714285714285720630e+00", "3FF9B6DB6DB6DB6E"},
{"+3.57142857142857150787e-01", "3FD6DB6DB6DB6DB7"},
};
// Compare decimal string -> double -> hex string to
// long hex string -> double hex string
for (int i = 0; i < testCases2.length; i++) {
String result;
String expected;
if(! (result=Double.toHexString(Double.parseDouble(testCases2[i][0]))).
equals( expected=hexLongStringtoHexDoubleString(testCases2[i][1]) )) {
failures ++;
System.err.println("For floating-point string " + testCases2[i][0] +
", expected hex output " + expected + ", got " + result +".");
}
}
// Test random double values;
// compare double -> Double.toHexString with local doubleToHexString
java.util.Random rand = new java.util.Random(0);
for (int i = 0; i < 1000; i++) {
String result;
String expected;
double d = rand.nextDouble();
if(! (expected=doubleToHexString(d)).equals(result=Double.toHexString(d)) ) {
failures ++;
System.err.println("For floating-point value " + d +
", expected hex output " + expected + ", got " + result +".");
}
}
return failures;
}
public static void main(String argv[]) {
int failures = 0;
failures = toHexStringTests();
if (failures != 0) {
throw new RuntimeException("" + failures + " failures while testing Double.toHexString");
}
}
}
|
