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
33 import java.util.regex.*;
34
35 public 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 }