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1 /*
2  * Copyright (c) 2003, 2017, 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 package test.java.lang.Double;
25 
26 /*
27  * @test
28  * @library /test/lib
29  * @build jdk.test.lib.RandomFactory
30  * @run main ParseHexFloatingPoint
31  * @bug 4826774 8078672
32  * @summary Numerical tests for hexadecimal inputs to parse{Double, Float} (use -Dseed=X to set PRNG seed)
33  * @author Joseph D. Darcy
34  * @key randomness
35  */
36 
37 import jdk.test.lib.RandomFactory;
38 
39 public class ParseHexFloatingPoint {
40     // Android-changed: JUnit expects exactly one public constructor.
41     // private ParseHexFloatingPoint(){}
42 
43     public static final double infinityD = Double.POSITIVE_INFINITY;
44     public static final double NaND = Double.NaN;
45 
test(String testName, String input, double result, double expected)46     static int test(String testName, String input,
47                     double result, double expected) {
48         int failures =0;
49 
50         if (Double.compare(result, expected) != 0 ) {
51             System.err.println("Failure for " + testName +
52                                ": For input " + input +
53                                " expected " + expected +
54                                " got " + result + ".");
55         }
56 
57         return failures;
58     }
59 
testCase(String input, double expected)60     static int testCase(String input, double expected) {
61         int failures =0;
62 
63 
64         // Try different combination of letter components
65         input = input.toLowerCase(java.util.Locale.US);
66 
67         String [] suffices = {"", "f", "F", "d", "D"};
68         String [] signs = {"", "-", "+"};
69 
70         for(int i = 0; i < 2; i++) {
71             String s1 = input;
72             if(i == 1)
73                 s1 = s1.replace('x', 'X');
74 
75             for(int j = 0; j < 2; j++) {
76                 String s2 = s1;
77                 if(j == 1)
78                     s2 = s2.replace('p', 'P');
79 
80                 for(int k = 0; k < 2; k++) {
81                     String s3 = s2;
82                     if(k == 1)
83                         s3 = upperCaseHex(s3);
84 
85 
86                     for(int m = 0; m < suffices.length; m++) {
87                         String s4 = s3 + suffices[m];
88 
89 
90                         for(int n = 0; n < signs.length; n++) {
91                             String s5 = signs[n] + s4;
92 
93                             double result = Double.parseDouble(s5);
94                             failures += test("Double.parseDouble",
95                                              s5, result, (signs[n].equals("-") ?
96                                                           -expected:
97                                                           expected));
98                         }
99                     }
100                 }
101             }
102         }
103 
104         return failures;
105     }
106 
upperCaseHex(String s)107     static String upperCaseHex(String s) {
108         return s.replace('a', 'A').replace('b', 'B').replace('c', 'C').
109                  replace('d', 'D').replace('e','E').replace('f', 'F');
110     }
111 
112     /*
113      * Test easy and tricky double rounding cases.
114      */
doubleTests()115     static int doubleTests() {
116 
117         /*
118          * A String, double pair
119          */
120         class PairSD {
121             public String s;
122             public double d;
123             PairSD(String s, double d) {
124                 this.s = s;
125                 this.d = d;
126             }
127         }
128         int failures = 0;
129 
130 
131 
132         // Hex strings that convert to three; test basic functionality
133         // of significand and exponent shift adjusts along with the
134         // no-op of adding leading zeros.  These cases don't exercise
135         // the rounding code.
136         String leadingZeros = "0x0000000000000000000";
137         String [] threeTests = {
138             "0x.003p12",
139             "0x.006p11",
140             "0x.00cp10",
141             "0x.018p9",
142 
143             "0x.3p4",
144             "0x.6p3",
145             "0x.cp2",
146             "0x1.8p1",
147 
148             "0x3p0",
149             "0x6.0p-1",
150             "0xc.0p-2",
151             "0x18.0p-3",
152 
153             "0x3000000p-24",
154             "0x3.0p0",
155             "0x3.000000p0",
156         };
157         for(int i=0; i < threeTests.length; i++) {
158             String input = threeTests[i];
159             failures += testCase(input, 3.0);
160 
161             input.replaceFirst("^0x", leadingZeros);
162             failures += testCase(input, 3.0);
163         }
164 
165         long bigExponents [] = {
166             2*Double.MAX_EXPONENT,
167             2*Double.MIN_EXPONENT,
168 
169             (long)Integer.MAX_VALUE-1,
170             (long)Integer.MAX_VALUE,
171             (long)Integer.MAX_VALUE+1,
172 
173             (long)Integer.MIN_VALUE-1,
174             (long)Integer.MIN_VALUE,
175             (long)Integer.MIN_VALUE+1,
176 
177             Long.MAX_VALUE-1,
178             Long.MAX_VALUE,
179 
180             Long.MIN_VALUE+1,
181             Long.MIN_VALUE,
182         };
183 
184         // Test zero significand with large exponents.
185         for(int i = 0; i < bigExponents.length; i++) {
186             failures += testCase("0x0.0p"+Long.toString(bigExponents[i]) , 0.0);
187         }
188 
189         // Test nonzero significand with large exponents.
190         for(int i = 0; i < bigExponents.length; i++) {
191             long exponent = bigExponents[i];
192             failures += testCase("0x10000.0p"+Long.toString(exponent) ,
193                                  (exponent <0?0.0:infinityD));
194         }
195 
196         // Test significands with different lengths and bit patterns.
197         {
198             long signif = 0;
199                 for(int i = 1; i <= 0xe; i++) {
200                     signif = (signif <<4) | (long)i;
201                     failures += testCase("0x"+Long.toHexString(signif)+"p0", signif);
202                 }
203         }
204 
205         PairSD [] testCases = {
206             new PairSD("0x0.0p0",               0.0/16.0),
207             new PairSD("0x0.1p0",               1.0/16.0),
208             new PairSD("0x0.2p0",               2.0/16.0),
209             new PairSD("0x0.3p0",               3.0/16.0),
210             new PairSD("0x0.4p0",               4.0/16.0),
211             new PairSD("0x0.5p0",               5.0/16.0),
212             new PairSD("0x0.6p0",               6.0/16.0),
213             new PairSD("0x0.7p0",               7.0/16.0),
214             new PairSD("0x0.8p0",               8.0/16.0),
215             new PairSD("0x0.9p0",               9.0/16.0),
216             new PairSD("0x0.ap0",               10.0/16.0),
217             new PairSD("0x0.bp0",               11.0/16.0),
218             new PairSD("0x0.cp0",               12.0/16.0),
219             new PairSD("0x0.dp0",               13.0/16.0),
220             new PairSD("0x0.ep0",               14.0/16.0),
221             new PairSD("0x0.fp0",               15.0/16.0),
222 
223             // Half-way case between zero and MIN_VALUE rounds down to
224             // zero
225             new PairSD("0x1.0p-1075",           0.0),
226 
227             // Slighly more than half-way case between zero and
228             // MIN_VALUES rounds up to zero.
229             new PairSD("0x1.1p-1075",                   Double.MIN_VALUE),
230             new PairSD("0x1.000000000001p-1075",        Double.MIN_VALUE),
231             new PairSD("0x1.000000000000001p-1075",     Double.MIN_VALUE),
232 
233             // More subnormal rounding tests
234             new PairSD("0x0.fffffffffffff7fffffp-1022", Math.nextDown(Double.MIN_NORMAL)),
235             new PairSD("0x0.fffffffffffff8p-1022",      Double.MIN_NORMAL),
236             new PairSD("0x0.fffffffffffff800000001p-1022",Double.MIN_NORMAL),
237             new PairSD("0x0.fffffffffffff80000000000000001p-1022",Double.MIN_NORMAL),
238             new PairSD("0x1.0p-1022",                   Double.MIN_NORMAL),
239 
240 
241             // Large value and overflow rounding tests
242             new PairSD("0x1.fffffffffffffp1023",        Double.MAX_VALUE),
243             new PairSD("0x1.fffffffffffff0000000p1023", Double.MAX_VALUE),
244             new PairSD("0x1.fffffffffffff4p1023",       Double.MAX_VALUE),
245             new PairSD("0x1.fffffffffffff7fffffp1023",  Double.MAX_VALUE),
246             new PairSD("0x1.fffffffffffff8p1023",       infinityD),
247             new PairSD("0x1.fffffffffffff8000001p1023", infinityD),
248 
249             new PairSD("0x1.ffffffffffffep1023",        Math.nextDown(Double.MAX_VALUE)),
250             new PairSD("0x1.ffffffffffffe0000p1023",    Math.nextDown(Double.MAX_VALUE)),
251             new PairSD("0x1.ffffffffffffe8p1023",       Math.nextDown(Double.MAX_VALUE)),
252             new PairSD("0x1.ffffffffffffe7p1023",       Math.nextDown(Double.MAX_VALUE)),
253             new PairSD("0x1.ffffffffffffeffffffp1023",  Double.MAX_VALUE),
254             new PairSD("0x1.ffffffffffffe8000001p1023", Double.MAX_VALUE),
255         };
256 
257         for (int i = 0; i < testCases.length; i++) {
258             failures += testCase(testCases[i].s,testCases[i].d);
259         }
260 
261         failures += significandAlignmentTests();
262 
263         {
264             java.util.Random rand = RandomFactory.getRandom();
265             // Consistency check; double => hexadecimal => double
266             // preserves the original value.
267             for(int i = 0; i < 1000; i++) {
268                 double d = rand.nextDouble();
269                 failures += testCase(Double.toHexString(d), d);
270             }
271         }
272 
273         return failures;
274     }
275 
276     /*
277      * Verify rounding works the same regardless of how the
278      * significand is aligned on input.  A useful extension could be
279      * to have this sort of test for strings near the overflow
280      * threshold.
281      */
significandAlignmentTests()282     static int significandAlignmentTests() {
283         int failures = 0;
284                 // baseSignif * 2^baseExp = nextDown(2.0)
285         long [] baseSignifs = {
286             0x1ffffffffffffe00L,
287             0x1fffffffffffff00L
288         };
289 
290         double [] answers = {
291             Math.nextDown(Math.nextDown(2.0)),
292             Math.nextDown(2.0),
293             2.0
294         };
295 
296         int baseExp = -60;
297         int count = 0;
298         for(int i = 0; i < 2; i++) {
299             for(long j = 0; j <= 0xfL; j++) {
300                 for(long k = 0; k <= 8; k+= 4) { // k = {0, 4, 8}
301                     long base = baseSignifs[i];
302                     long testValue = base | (j<<4) | k;
303 
304                     int offset = 0;
305                     // Calculate when significand should be incremented
306                     // see table 4.7 in Koren book
307 
308                     if ((base & 0x100L) == 0L ) { // lsb is 0
309                         if ( (j >= 8L) &&         // round is 1
310                              ((j & 0x7L) != 0 || k != 0 ) ) // sticky is 1
311                             offset = 1;
312                     }
313                     else {                        // lsb is 1
314                         if (j >= 8L)              // round is 1
315                             offset = 1;
316                     }
317 
318                     double expected = answers[i+offset];
319 
320                     for(int m = -2; m <= 3; m++) {
321                         count ++;
322 
323                         // Form equal value string and evaluate it
324                         String s = "0x" +
325                             Long.toHexString((m >=0) ?(testValue<<m):(testValue>>(-m))) +
326                             "p" + (baseExp - m);
327 
328                         failures += testCase(s, expected);
329                     }
330                 }
331             }
332         }
333 
334         return failures;
335     }
336 
337 
338     /*
339      * Test tricky float rounding cases.  The code which
340      * reads in a hex string converts the string to a double value.
341      * If a float value is needed, the double value is cast to float.
342      * However, the cast be itself not always guaranteed to return the
343      * right result since:
344      *
345      * 1. hex string => double can discard a sticky bit which would
346      * influence a direct hex string => float conversion.
347      *
348      * 2. hex string => double => float can have a rounding to double
349      * precision which results in a larger float value while a direct
350      * hex string => float conversion would not round up.
351      *
352      * This method includes tests of the latter two possibilities.
353      */
floatTests()354     static int floatTests(){
355         int failures = 0;
356 
357         /*
358          * A String, float pair
359          */
360         class PairSD {
361             public String s;
362             public float f;
363             PairSD(String s, float f) {
364                 this.s = s;
365                 this.f = f;
366             }
367         }
368 
369         String [][] roundingTestCases = {
370             // Target float value       hard rouding version
371 
372             {"0x1.000000p0",    "0x1.0000000000001p0"},
373 
374             // Try some values that should round up to nextUp(1.0f)
375             {"0x1.000002p0",    "0x1.0000010000001p0"},
376             {"0x1.000002p0",    "0x1.00000100000008p0"},
377             {"0x1.000002p0",    "0x1.0000010000000fp0"},
378             {"0x1.000002p0",    "0x1.00000100000001p0"},
379             {"0x1.000002p0",    "0x1.00000100000000000000000000000000000000001p0"},
380             {"0x1.000002p0",    "0x1.0000010000000fp0"},
381 
382             // Potential double rounding cases
383             {"0x1.000002p0",    "0x1.000002fffffffp0"},
384             {"0x1.000002p0",    "0x1.000002fffffff8p0"},
385             {"0x1.000002p0",    "0x1.000002ffffffffp0"},
386 
387             {"0x1.000002p0",    "0x1.000002ffff0ffp0"},
388             {"0x1.000002p0",    "0x1.000002ffff0ff8p0"},
389             {"0x1.000002p0",    "0x1.000002ffff0fffp0"},
390 
391 
392             {"0x1.000000p0",    "0x1.000000fffffffp0"},
393             {"0x1.000000p0",    "0x1.000000fffffff8p0"},
394             {"0x1.000000p0",    "0x1.000000ffffffffp0"},
395 
396             {"0x1.000000p0",    "0x1.000000ffffffep0"},
397             {"0x1.000000p0",    "0x1.000000ffffffe8p0"},
398             {"0x1.000000p0",    "0x1.000000ffffffefp0"},
399 
400             // Float subnormal cases
401             {"0x0.000002p-126", "0x0.0000010000001p-126"},
402             {"0x0.000002p-126", "0x0.00000100000000000001p-126"},
403 
404             {"0x0.000006p-126", "0x0.0000050000001p-126"},
405             {"0x0.000006p-126", "0x0.00000500000000000001p-126"},
406 
407             {"0x0.0p-149",      "0x0.7ffffffffffffffp-149"},
408             {"0x1.0p-148",      "0x1.3ffffffffffffffp-148"},
409             {"0x1.cp-147",      "0x1.bffffffffffffffp-147"},
410 
411             {"0x1.fffffcp-127", "0x1.fffffdffffffffp-127"},
412         };
413 
414         String [] signs = {"", "-"};
415 
416         for(int i = 0; i < roundingTestCases.length; i++) {
417             for(int j = 0; j < signs.length; j++) {
418                 String expectedIn = signs[j]+roundingTestCases[i][0];
419                 String resultIn   = signs[j]+roundingTestCases[i][1];
420 
421                 float expected =  Float.parseFloat(expectedIn);
422                 float result   =  Float.parseFloat(resultIn);
423 
424                 if( Float.compare(expected, result) != 0) {
425                     failures += 1;
426                     System.err.println("" + (i+1));
427                     System.err.println("Expected = " + Float.toHexString(expected));
428                     System.err.println("Rounded  = " + Float.toHexString(result));
429                     System.err.println("Double   = " + Double.toHexString(Double.parseDouble(resultIn)));
430                     System.err.println("Input    = " + resultIn);
431                     System.err.println("");
432                 }
433             }
434         }
435 
436         return failures;
437     }
438 
main(String argv[])439     public static void main(String argv[]) {
440         int failures = 0;
441 
442         failures += doubleTests();
443         failures += floatTests();
444 
445         if (failures != 0) {
446             throw new RuntimeException("" + failures + " failures while " +
447                                        "testing hexadecimal floating-point " +
448                                        "parsing.");
449         }
450     }
451 
452 }
453