1// Copyright 2006-2008 the V8 project authors. All rights reserved.
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27
28#include <stdlib.h>
29
30#include "src/v8.h"
31
32#include "src/base/platform/platform.h"
33#include "src/diy-fp.h"
34#include "src/double.h"
35#include "src/fast-dtoa.h"
36#include "test/cctest/cctest.h"
37#include "test/cctest/gay-precision.h"
38#include "test/cctest/gay-shortest.h"
39
40using namespace v8::internal;
41
42static const int kBufferSize = 100;
43
44
45// Removes trailing '0' digits.
46static void TrimRepresentation(Vector<char> representation) {
47  int len = StrLength(representation.start());
48  int i;
49  for (i = len - 1; i >= 0; --i) {
50    if (representation[i] != '0') break;
51  }
52  representation[i + 1] = '\0';
53}
54
55
56TEST(FastDtoaShortestVariousDoubles) {
57  char buffer_container[kBufferSize];
58  Vector<char> buffer(buffer_container, kBufferSize);
59  int length;
60  int point;
61  int status;
62
63  double min_double = 5e-324;
64  status = FastDtoa(min_double, FAST_DTOA_SHORTEST, 0,
65                    buffer, &length, &point);
66  CHECK(status);
67  CHECK_EQ("5", buffer.start());
68  CHECK_EQ(-323, point);
69
70  double max_double = 1.7976931348623157e308;
71  status = FastDtoa(max_double, FAST_DTOA_SHORTEST, 0,
72                    buffer, &length, &point);
73  CHECK(status);
74  CHECK_EQ("17976931348623157", buffer.start());
75  CHECK_EQ(309, point);
76
77  status = FastDtoa(4294967272.0, FAST_DTOA_SHORTEST, 0,
78                    buffer, &length, &point);
79  CHECK(status);
80  CHECK_EQ("4294967272", buffer.start());
81  CHECK_EQ(10, point);
82
83  status = FastDtoa(4.1855804968213567e298, FAST_DTOA_SHORTEST, 0,
84                    buffer, &length, &point);
85  CHECK(status);
86  CHECK_EQ("4185580496821357", buffer.start());
87  CHECK_EQ(299, point);
88
89  status = FastDtoa(5.5626846462680035e-309, FAST_DTOA_SHORTEST, 0,
90                    buffer, &length, &point);
91  CHECK(status);
92  CHECK_EQ("5562684646268003", buffer.start());
93  CHECK_EQ(-308, point);
94
95  status = FastDtoa(2147483648.0, FAST_DTOA_SHORTEST, 0,
96                    buffer, &length, &point);
97  CHECK(status);
98  CHECK_EQ("2147483648", buffer.start());
99  CHECK_EQ(10, point);
100
101  status = FastDtoa(3.5844466002796428e+298, FAST_DTOA_SHORTEST, 0,
102                    buffer, &length, &point);
103  if (status) {  // Not all FastDtoa variants manage to compute this number.
104    CHECK_EQ("35844466002796428", buffer.start());
105    CHECK_EQ(299, point);
106  }
107
108  uint64_t smallest_normal64 = V8_2PART_UINT64_C(0x00100000, 00000000);
109  double v = Double(smallest_normal64).value();
110  status = FastDtoa(v, FAST_DTOA_SHORTEST, 0, buffer, &length, &point);
111  if (status) {
112    CHECK_EQ("22250738585072014", buffer.start());
113    CHECK_EQ(-307, point);
114  }
115
116  uint64_t largest_denormal64 = V8_2PART_UINT64_C(0x000FFFFF, FFFFFFFF);
117  v = Double(largest_denormal64).value();
118  status = FastDtoa(v, FAST_DTOA_SHORTEST, 0, buffer, &length, &point);
119  if (status) {
120    CHECK_EQ("2225073858507201", buffer.start());
121    CHECK_EQ(-307, point);
122  }
123}
124
125
126TEST(FastDtoaPrecisionVariousDoubles) {
127  char buffer_container[kBufferSize];
128  Vector<char> buffer(buffer_container, kBufferSize);
129  int length;
130  int point;
131  int status;
132
133  status = FastDtoa(1.0, FAST_DTOA_PRECISION, 3, buffer, &length, &point);
134  CHECK(status);
135  CHECK_GE(3, length);
136  TrimRepresentation(buffer);
137  CHECK_EQ("1", buffer.start());
138  CHECK_EQ(1, point);
139
140  status = FastDtoa(1.5, FAST_DTOA_PRECISION, 10, buffer, &length, &point);
141  if (status) {
142    CHECK_GE(10, length);
143    TrimRepresentation(buffer);
144    CHECK_EQ("15", buffer.start());
145    CHECK_EQ(1, point);
146  }
147
148  double min_double = 5e-324;
149  status = FastDtoa(min_double, FAST_DTOA_PRECISION, 5,
150                    buffer, &length, &point);
151  CHECK(status);
152  CHECK_EQ("49407", buffer.start());
153  CHECK_EQ(-323, point);
154
155  double max_double = 1.7976931348623157e308;
156  status = FastDtoa(max_double, FAST_DTOA_PRECISION, 7,
157                    buffer, &length, &point);
158  CHECK(status);
159  CHECK_EQ("1797693", buffer.start());
160  CHECK_EQ(309, point);
161
162  status = FastDtoa(4294967272.0, FAST_DTOA_PRECISION, 14,
163                    buffer, &length, &point);
164  if (status) {
165    CHECK_GE(14, length);
166    TrimRepresentation(buffer);
167    CHECK_EQ("4294967272", buffer.start());
168    CHECK_EQ(10, point);
169  }
170
171  status = FastDtoa(4.1855804968213567e298, FAST_DTOA_PRECISION, 17,
172                    buffer, &length, &point);
173  CHECK(status);
174  CHECK_EQ("41855804968213567", buffer.start());
175  CHECK_EQ(299, point);
176
177  status = FastDtoa(5.5626846462680035e-309, FAST_DTOA_PRECISION, 1,
178                    buffer, &length, &point);
179  CHECK(status);
180  CHECK_EQ("6", buffer.start());
181  CHECK_EQ(-308, point);
182
183  status = FastDtoa(2147483648.0, FAST_DTOA_PRECISION, 5,
184                    buffer, &length, &point);
185  CHECK(status);
186  CHECK_EQ("21475", buffer.start());
187  CHECK_EQ(10, point);
188
189  status = FastDtoa(3.5844466002796428e+298, FAST_DTOA_PRECISION, 10,
190                    buffer, &length, &point);
191  CHECK(status);
192  CHECK_GE(10, length);
193  TrimRepresentation(buffer);
194  CHECK_EQ("35844466", buffer.start());
195  CHECK_EQ(299, point);
196
197  uint64_t smallest_normal64 = V8_2PART_UINT64_C(0x00100000, 00000000);
198  double v = Double(smallest_normal64).value();
199  status = FastDtoa(v, FAST_DTOA_PRECISION, 17, buffer, &length, &point);
200  CHECK(status);
201  CHECK_EQ("22250738585072014", buffer.start());
202  CHECK_EQ(-307, point);
203
204  uint64_t largest_denormal64 = V8_2PART_UINT64_C(0x000FFFFF, FFFFFFFF);
205  v = Double(largest_denormal64).value();
206  status = FastDtoa(v, FAST_DTOA_PRECISION, 17, buffer, &length, &point);
207  CHECK(status);
208  CHECK_GE(20, length);
209  TrimRepresentation(buffer);
210  CHECK_EQ("22250738585072009", buffer.start());
211  CHECK_EQ(-307, point);
212
213  v = 3.3161339052167390562200598e-237;
214  status = FastDtoa(v, FAST_DTOA_PRECISION, 18, buffer, &length, &point);
215  CHECK(status);
216  CHECK_EQ("331613390521673906", buffer.start());
217  CHECK_EQ(-236, point);
218
219  v = 7.9885183916008099497815232e+191;
220  status = FastDtoa(v, FAST_DTOA_PRECISION, 4, buffer, &length, &point);
221  CHECK(status);
222  CHECK_EQ("7989", buffer.start());
223  CHECK_EQ(192, point);
224}
225
226
227TEST(FastDtoaGayShortest) {
228  char buffer_container[kBufferSize];
229  Vector<char> buffer(buffer_container, kBufferSize);
230  bool status;
231  int length;
232  int point;
233  int succeeded = 0;
234  int total = 0;
235  bool needed_max_length = false;
236
237  Vector<const PrecomputedShortest> precomputed =
238      PrecomputedShortestRepresentations();
239  for (int i = 0; i < precomputed.length(); ++i) {
240    const PrecomputedShortest current_test = precomputed[i];
241    total++;
242    double v = current_test.v;
243    status = FastDtoa(v, FAST_DTOA_SHORTEST, 0, buffer, &length, &point);
244    CHECK_GE(kFastDtoaMaximalLength, length);
245    if (!status) continue;
246    if (length == kFastDtoaMaximalLength) needed_max_length = true;
247    succeeded++;
248    CHECK_EQ(current_test.decimal_point, point);
249    CHECK_EQ(current_test.representation, buffer.start());
250  }
251  CHECK_GT(succeeded*1.0/total, 0.99);
252  CHECK(needed_max_length);
253}
254
255
256TEST(FastDtoaGayPrecision) {
257  char buffer_container[kBufferSize];
258  Vector<char> buffer(buffer_container, kBufferSize);
259  bool status;
260  int length;
261  int point;
262  int succeeded = 0;
263  int total = 0;
264  // Count separately for entries with less than 15 requested digits.
265  int succeeded_15 = 0;
266  int total_15 = 0;
267
268  Vector<const PrecomputedPrecision> precomputed =
269      PrecomputedPrecisionRepresentations();
270  for (int i = 0; i < precomputed.length(); ++i) {
271    const PrecomputedPrecision current_test = precomputed[i];
272    double v = current_test.v;
273    int number_digits = current_test.number_digits;
274    total++;
275    if (number_digits <= 15) total_15++;
276    status = FastDtoa(v, FAST_DTOA_PRECISION, number_digits,
277                      buffer, &length, &point);
278    CHECK_GE(number_digits, length);
279    if (!status) continue;
280    succeeded++;
281    if (number_digits <= 15) succeeded_15++;
282    TrimRepresentation(buffer);
283    CHECK_EQ(current_test.decimal_point, point);
284    CHECK_EQ(current_test.representation, buffer.start());
285  }
286  // The precomputed numbers contain many entries with many requested
287  // digits. These have a high failure rate and we therefore expect a lower
288  // success rate than for the shortest representation.
289  CHECK_GT(succeeded*1.0/total, 0.85);
290  // However with less than 15 digits almost the algorithm should almost always
291  // succeed.
292  CHECK_GT(succeeded_15*1.0/total_15, 0.9999);
293}
294