ToHexString.java revision 6073:cea72c2bf071
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 * @author Joseph D. Darcy 29 */ 30 31import java.util.regex.*; 32import sun.misc.DoubleConsts; 33 34public 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} 252