ParseHexFloatingPoint.java revision 11822:110f7f35760f
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 27 * @summary Numerical tests for hexadecimal inputs to parseDouble, parseFloat 28 * @author Joseph D. Darcy 29 * @key randomness 30 */ 31 32 33import java.util.regex.*; 34 35public class ParseHexFloatingPoint { 36 private ParseHexFloatingPoint(){} 37 38 public static final double infinityD = Double.POSITIVE_INFINITY; 39 public static final double NaND = Double.NaN; 40 41 static int test(String testName, String input, 42 double result, double expected) { 43 int failures =0; 44 45 if (Double.compare(result, expected) != 0 ) { 46 System.err.println("Failure for " + testName + 47 ": For input " + input + 48 " expected " + expected + 49 " got " + result + "."); 50 } 51 52 return failures; 53 } 54 55 static int testCase(String input, double expected) { 56 int failures =0; 57 58 59 // Try different combination of letter components 60 input = input.toLowerCase(java.util.Locale.US); 61 62 String [] suffices = {"", "f", "F", "d", "D"}; 63 String [] signs = {"", "-", "+"}; 64 65 for(int i = 0; i < 2; i++) { 66 String s1 = input; 67 if(i == 1) 68 s1 = s1.replace('x', 'X'); 69 70 for(int j = 0; j < 2; j++) { 71 String s2 = s1; 72 if(j == 1) 73 s2 = s2.replace('p', 'P'); 74 75 for(int k = 0; k < 2; k++) { 76 String s3 = s2; 77 if(k == 1) 78 s3 = upperCaseHex(s3); 79 80 81 for(int m = 0; m < suffices.length; m++) { 82 String s4 = s3 + suffices[m]; 83 84 85 for(int n = 0; n < signs.length; n++) { 86 String s5 = signs[n] + s4; 87 88 double result = Double.parseDouble(s5); 89 failures += test("Double.parseDouble", 90 s5, result, (signs[n].equals("-") ? 91 -expected: 92 expected)); 93 } 94 } 95 } 96 } 97 } 98 99 return failures; 100 } 101 102 static String upperCaseHex(String s) { 103 return s.replace('a', 'A').replace('b', 'B').replace('c', 'C'). 104 replace('d', 'D').replace('e','E').replace('f', 'F'); 105 } 106 107 /* 108 * Test easy and tricky double rounding cases. 109 */ 110 static int doubleTests() { 111 112 /* 113 * A String, double pair 114 */ 115 class PairSD { 116 public String s; 117 public double d; 118 PairSD(String s, double d) { 119 this.s = s; 120 this.d = d; 121 } 122 } 123 int failures = 0; 124 125 126 127 // Hex strings that convert to three; test basic functionality 128 // of significand and exponent shift adjusts along with the 129 // no-op of adding leading zeros. These cases don't exercise 130 // the rounding code. 131 String leadingZeros = "0x0000000000000000000"; 132 String [] threeTests = { 133 "0x.003p12", 134 "0x.006p11", 135 "0x.00cp10", 136 "0x.018p9", 137 138 "0x.3p4", 139 "0x.6p3", 140 "0x.cp2", 141 "0x1.8p1", 142 143 "0x3p0", 144 "0x6.0p-1", 145 "0xc.0p-2", 146 "0x18.0p-3", 147 148 "0x3000000p-24", 149 "0x3.0p0", 150 "0x3.000000p0", 151 }; 152 for(int i=0; i < threeTests.length; i++) { 153 String input = threeTests[i]; 154 failures += testCase(input, 3.0); 155 156 input.replaceFirst("^0x", leadingZeros); 157 failures += testCase(input, 3.0); 158 } 159 160 long bigExponents [] = { 161 2*Double.MAX_EXPONENT, 162 2*Double.MIN_EXPONENT, 163 164 (long)Integer.MAX_VALUE-1, 165 (long)Integer.MAX_VALUE, 166 (long)Integer.MAX_VALUE+1, 167 168 (long)Integer.MIN_VALUE-1, 169 (long)Integer.MIN_VALUE, 170 (long)Integer.MIN_VALUE+1, 171 172 Long.MAX_VALUE-1, 173 Long.MAX_VALUE, 174 175 Long.MIN_VALUE+1, 176 Long.MIN_VALUE, 177 }; 178 179 // Test zero significand with large exponents. 180 for(int i = 0; i < bigExponents.length; i++) { 181 failures += testCase("0x0.0p"+Long.toString(bigExponents[i]) , 0.0); 182 } 183 184 // Test nonzero significand with large exponents. 185 for(int i = 0; i < bigExponents.length; i++) { 186 long exponent = bigExponents[i]; 187 failures += testCase("0x10000.0p"+Long.toString(exponent) , 188 (exponent <0?0.0:infinityD)); 189 } 190 191 // Test significands with different lengths and bit patterns. 192 { 193 long signif = 0; 194 for(int i = 1; i <= 0xe; i++) { 195 signif = (signif <<4) | (long)i; 196 failures += testCase("0x"+Long.toHexString(signif)+"p0", signif); 197 } 198 } 199 200 PairSD [] testCases = { 201 new PairSD("0x0.0p0", 0.0/16.0), 202 new PairSD("0x0.1p0", 1.0/16.0), 203 new PairSD("0x0.2p0", 2.0/16.0), 204 new PairSD("0x0.3p0", 3.0/16.0), 205 new PairSD("0x0.4p0", 4.0/16.0), 206 new PairSD("0x0.5p0", 5.0/16.0), 207 new PairSD("0x0.6p0", 6.0/16.0), 208 new PairSD("0x0.7p0", 7.0/16.0), 209 new PairSD("0x0.8p0", 8.0/16.0), 210 new PairSD("0x0.9p0", 9.0/16.0), 211 new PairSD("0x0.ap0", 10.0/16.0), 212 new PairSD("0x0.bp0", 11.0/16.0), 213 new PairSD("0x0.cp0", 12.0/16.0), 214 new PairSD("0x0.dp0", 13.0/16.0), 215 new PairSD("0x0.ep0", 14.0/16.0), 216 new PairSD("0x0.fp0", 15.0/16.0), 217 218 // Half-way case between zero and MIN_VALUE rounds down to 219 // zero 220 new PairSD("0x1.0p-1075", 0.0), 221 222 // Slighly more than half-way case between zero and 223 // MIN_VALUES rounds up to zero. 224 new PairSD("0x1.1p-1075", Double.MIN_VALUE), 225 new PairSD("0x1.000000000001p-1075", Double.MIN_VALUE), 226 new PairSD("0x1.000000000000001p-1075", Double.MIN_VALUE), 227 228 // More subnormal rounding tests 229 new PairSD("0x0.fffffffffffff7fffffp-1022", Math.nextDown(Double.MIN_NORMAL)), 230 new PairSD("0x0.fffffffffffff8p-1022", Double.MIN_NORMAL), 231 new PairSD("0x0.fffffffffffff800000001p-1022",Double.MIN_NORMAL), 232 new PairSD("0x0.fffffffffffff80000000000000001p-1022",Double.MIN_NORMAL), 233 new PairSD("0x1.0p-1022", Double.MIN_NORMAL), 234 235 236 // Large value and overflow rounding tests 237 new PairSD("0x1.fffffffffffffp1023", Double.MAX_VALUE), 238 new PairSD("0x1.fffffffffffff0000000p1023", Double.MAX_VALUE), 239 new PairSD("0x1.fffffffffffff4p1023", Double.MAX_VALUE), 240 new PairSD("0x1.fffffffffffff7fffffp1023", Double.MAX_VALUE), 241 new PairSD("0x1.fffffffffffff8p1023", infinityD), 242 new PairSD("0x1.fffffffffffff8000001p1023", infinityD), 243 244 new PairSD("0x1.ffffffffffffep1023", Math.nextDown(Double.MAX_VALUE)), 245 new PairSD("0x1.ffffffffffffe0000p1023", Math.nextDown(Double.MAX_VALUE)), 246 new PairSD("0x1.ffffffffffffe8p1023", Math.nextDown(Double.MAX_VALUE)), 247 new PairSD("0x1.ffffffffffffe7p1023", Math.nextDown(Double.MAX_VALUE)), 248 new PairSD("0x1.ffffffffffffeffffffp1023", Double.MAX_VALUE), 249 new PairSD("0x1.ffffffffffffe8000001p1023", Double.MAX_VALUE), 250 }; 251 252 for (int i = 0; i < testCases.length; i++) { 253 failures += testCase(testCases[i].s,testCases[i].d); 254 } 255 256 failures += significandAlignmentTests(); 257 258 { 259 java.util.Random rand = new java.util.Random(); 260 // Consistency check; double => hexadecimal => double 261 // preserves the original value. 262 for(int i = 0; i < 1000; i++) { 263 double d = rand.nextDouble(); 264 failures += testCase(Double.toHexString(d), d); 265 } 266 } 267 268 return failures; 269 } 270 271 /* 272 * Verify rounding works the same regardless of how the 273 * significand is aligned on input. A useful extension could be 274 * to have this sort of test for strings near the overflow 275 * threshold. 276 */ 277 static int significandAlignmentTests() { 278 int failures = 0; 279 // baseSignif * 2^baseExp = nextDown(2.0) 280 long [] baseSignifs = { 281 0x1ffffffffffffe00L, 282 0x1fffffffffffff00L 283 }; 284 285 double [] answers = { 286 Math.nextDown(Math.nextDown(2.0)), 287 Math.nextDown(2.0), 288 2.0 289 }; 290 291 int baseExp = -60; 292 int count = 0; 293 for(int i = 0; i < 2; i++) { 294 for(long j = 0; j <= 0xfL; j++) { 295 for(long k = 0; k <= 8; k+= 4) { // k = {0, 4, 8} 296 long base = baseSignifs[i]; 297 long testValue = base | (j<<4) | k; 298 299 int offset = 0; 300 // Calculate when significand should be incremented 301 // see table 4.7 in Koren book 302 303 if ((base & 0x100L) == 0L ) { // lsb is 0 304 if ( (j >= 8L) && // round is 1 305 ((j & 0x7L) != 0 || k != 0 ) ) // sticky is 1 306 offset = 1; 307 } 308 else { // lsb is 1 309 if (j >= 8L) // round is 1 310 offset = 1; 311 } 312 313 double expected = answers[i+offset]; 314 315 for(int m = -2; m <= 3; m++) { 316 count ++; 317 318 // Form equal value string and evaluate it 319 String s = "0x" + 320 Long.toHexString((m >=0) ?(testValue<<m):(testValue>>(-m))) + 321 "p" + (baseExp - m); 322 323 failures += testCase(s, expected); 324 } 325 } 326 } 327 } 328 329 return failures; 330 } 331 332 333 /* 334 * Test tricky float rounding cases. The code which 335 * reads in a hex string converts the string to a double value. 336 * If a float value is needed, the double value is cast to float. 337 * However, the cast be itself not always guaranteed to return the 338 * right result since: 339 * 340 * 1. hex string => double can discard a sticky bit which would 341 * influence a direct hex string => float conversion. 342 * 343 * 2. hex string => double => float can have a rounding to double 344 * precision which results in a larger float value while a direct 345 * hex string => float conversion would not round up. 346 * 347 * This method includes tests of the latter two possibilities. 348 */ 349 static int floatTests(){ 350 int failures = 0; 351 352 /* 353 * A String, float pair 354 */ 355 class PairSD { 356 public String s; 357 public float f; 358 PairSD(String s, float f) { 359 this.s = s; 360 this.f = f; 361 } 362 } 363 364 String [][] roundingTestCases = { 365 // Target float value hard rouding version 366 367 {"0x1.000000p0", "0x1.0000000000001p0"}, 368 369 // Try some values that should round up to nextUp(1.0f) 370 {"0x1.000002p0", "0x1.0000010000001p0"}, 371 {"0x1.000002p0", "0x1.00000100000008p0"}, 372 {"0x1.000002p0", "0x1.0000010000000fp0"}, 373 {"0x1.000002p0", "0x1.00000100000001p0"}, 374 {"0x1.000002p0", "0x1.00000100000000000000000000000000000000001p0"}, 375 {"0x1.000002p0", "0x1.0000010000000fp0"}, 376 377 // Potential double rounding cases 378 {"0x1.000002p0", "0x1.000002fffffffp0"}, 379 {"0x1.000002p0", "0x1.000002fffffff8p0"}, 380 {"0x1.000002p0", "0x1.000002ffffffffp0"}, 381 382 {"0x1.000002p0", "0x1.000002ffff0ffp0"}, 383 {"0x1.000002p0", "0x1.000002ffff0ff8p0"}, 384 {"0x1.000002p0", "0x1.000002ffff0fffp0"}, 385 386 387 {"0x1.000000p0", "0x1.000000fffffffp0"}, 388 {"0x1.000000p0", "0x1.000000fffffff8p0"}, 389 {"0x1.000000p0", "0x1.000000ffffffffp0"}, 390 391 {"0x1.000000p0", "0x1.000000ffffffep0"}, 392 {"0x1.000000p0", "0x1.000000ffffffe8p0"}, 393 {"0x1.000000p0", "0x1.000000ffffffefp0"}, 394 395 // Float subnormal cases 396 {"0x0.000002p-126", "0x0.0000010000001p-126"}, 397 {"0x0.000002p-126", "0x0.00000100000000000001p-126"}, 398 399 {"0x0.000006p-126", "0x0.0000050000001p-126"}, 400 {"0x0.000006p-126", "0x0.00000500000000000001p-126"}, 401 402 {"0x0.0p-149", "0x0.7ffffffffffffffp-149"}, 403 {"0x1.0p-148", "0x1.3ffffffffffffffp-148"}, 404 {"0x1.cp-147", "0x1.bffffffffffffffp-147"}, 405 406 {"0x1.fffffcp-127", "0x1.fffffdffffffffp-127"}, 407 }; 408 409 String [] signs = {"", "-"}; 410 411 for(int i = 0; i < roundingTestCases.length; i++) { 412 for(int j = 0; j < signs.length; j++) { 413 String expectedIn = signs[j]+roundingTestCases[i][0]; 414 String resultIn = signs[j]+roundingTestCases[i][1]; 415 416 float expected = Float.parseFloat(expectedIn); 417 float result = Float.parseFloat(resultIn); 418 419 if( Float.compare(expected, result) != 0) { 420 failures += 1; 421 System.err.println("" + (i+1)); 422 System.err.println("Expected = " + Float.toHexString(expected)); 423 System.err.println("Rounded = " + Float.toHexString(result)); 424 System.err.println("Double = " + Double.toHexString(Double.parseDouble(resultIn))); 425 System.err.println("Input = " + resultIn); 426 System.err.println(""); 427 } 428 } 429 } 430 431 return failures; 432 } 433 434 public static void main(String argv[]) { 435 int failures = 0; 436 437 failures += doubleTests(); 438 failures += floatTests(); 439 440 if (failures != 0) { 441 throw new RuntimeException("" + failures + " failures while " + 442 "testing hexadecimal floating-point " + 443 "parsing."); 444 } 445 } 446 447} 448