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