1 // Copyright 2006-2008 the V8 project authors. All rights reserved.
2 // Redistribution and use in source and binary forms, with or without
3 // modification, are permitted provided that the following conditions are
4 // met:
5 //
6 // * Redistributions of source code must retain the above copyright
7 // notice, this list of conditions and the following disclaimer.
8 // * Redistributions in binary form must reproduce the above
9 // copyright notice, this list of conditions and the following
10 // disclaimer in the documentation and/or other materials provided
11 // with the distribution.
12 // * Neither the name of Google Inc. nor the names of its
13 // contributors may be used to endorse or promote products derived
14 // from this software without specific prior written permission.
15 //
16 // THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
17 // "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
18 // LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
19 // A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
20 // OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
21 // SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
22 // LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
23 // DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
24 // THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
25 // (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
26 // OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
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
40 using namespace v8::internal;
41
42 static const int kBufferSize = 100;
43
44
45 // Removes trailing '0' digits.
TrimRepresentation(Vector<char> representation)46 static 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
TEST(FastDtoaShortestVariousDoubles)56 TEST(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
TEST(FastDtoaPrecisionVariousDoubles)126 TEST(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
TEST(FastDtoaGayShortest)227 TEST(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
TEST(FastDtoaGayPrecision)256 TEST(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