1 // Translated from C to Rust. The original C code can be found at
2 // https://github.com/ulfjack/ryu and carries the following license:
3 //
4 // Copyright 2018 Ulf Adams
5 //
6 // The contents of this file may be used under the terms of the Apache License,
7 // Version 2.0.
8 //
9 //    (See accompanying file LICENSE-Apache or copy at
10 //     http://www.apache.org/licenses/LICENSE-2.0)
11 //
12 // Alternatively, the contents of this file may be used under the terms of
13 // the Boost Software License, Version 1.0.
14 //    (See accompanying file LICENSE-Boost or copy at
15 //     https://www.boost.org/LICENSE_1_0.txt)
16 //
17 // Unless required by applicable law or agreed to in writing, this software
18 // is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
19 // KIND, either express or implied.
20 
21 extern crate rand;
22 extern crate ryu;
23 
24 #[macro_use]
25 mod macros;
26 
27 use std::f64;
28 
pretty(f: f64) -> String29 fn pretty(f: f64) -> String {
30     ryu::Buffer::new().format(f).to_owned()
31 }
32 
ieee_parts_to_double(sign: bool, ieee_exponent: u32, ieee_mantissa: u64) -> f6433 fn ieee_parts_to_double(sign: bool, ieee_exponent: u32, ieee_mantissa: u64) -> f64 {
34     assert!(ieee_exponent <= 2047);
35     assert!(ieee_mantissa <= (1u64 << 53) - 1);
36     f64::from_bits(((sign as u64) << 63) | ((ieee_exponent as u64) << 52) | ieee_mantissa)
37 }
38 
39 #[test]
test_ryu()40 fn test_ryu() {
41     check!(0.3);
42     check!(1234000000000000.0);
43     check!(1.234e16);
44     check!(2.71828);
45     check!(1.1e128);
46     check!(1.1e-64);
47     check!(2.718281828459045);
48     check!(5e-324);
49     check!(1.7976931348623157e308);
50 }
51 
52 #[test]
test_random()53 fn test_random() {
54     let mut buffer = ryu::Buffer::new();
55     for _ in 0..1000000 {
56         let f: f64 = rand::random();
57         assert_eq!(f, buffer.format_finite(f).parse().unwrap());
58     }
59 }
60 
61 #[test]
test_non_finite()62 fn test_non_finite() {
63     for i in 0u64..1 << 23 {
64         let f = f64::from_bits((((1 << 11) - 1) << 52) + (i << 29));
65         assert!(!f.is_finite(), "f={}", f);
66         ryu::Buffer::new().format_finite(f);
67     }
68 }
69 
70 #[test]
test_basic()71 fn test_basic() {
72     check!(0.0);
73     check!(-0.0);
74     check!(1.0);
75     check!(-1.0);
76     assert_eq!(pretty(f64::NAN), "NaN");
77     assert_eq!(pretty(f64::INFINITY), "inf");
78     assert_eq!(pretty(f64::NEG_INFINITY), "-inf");
79 }
80 
81 #[test]
test_switch_to_subnormal()82 fn test_switch_to_subnormal() {
83     check!(2.2250738585072014e-308);
84 }
85 
86 #[test]
test_min_and_max()87 fn test_min_and_max() {
88     assert_eq!(f64::from_bits(0x7fefffffffffffff), 1.7976931348623157e308);
89     check!(1.7976931348623157e308);
90     assert_eq!(f64::from_bits(1), 5e-324);
91     check!(5e-324);
92 }
93 
94 #[test]
test_lots_of_trailing_zeros()95 fn test_lots_of_trailing_zeros() {
96     check!(2.9802322387695312e-8);
97 }
98 
99 #[test]
test_regression()100 fn test_regression() {
101     check!(-2.109808898695963e16);
102     check!(4.940656e-318);
103     check!(1.18575755e-316);
104     check!(2.989102097996e-312);
105     check!(9060801153433600.0);
106     check!(4.708356024711512e18);
107     check!(9.409340012568248e18);
108     check!(1.2345678);
109 }
110 
111 #[test]
test_looks_like_pow5()112 fn test_looks_like_pow5() {
113     // These numbers have a mantissa that is a multiple of the largest power of
114     // 5 that fits, and an exponent that causes the computation for q to result
115     // in 22, which is a corner case for Ryu.
116     assert_eq!(f64::from_bits(0x4830F0CF064DD592), 5.764607523034235e39);
117     check!(5.764607523034235e39);
118     assert_eq!(f64::from_bits(0x4840F0CF064DD592), 1.152921504606847e40);
119     check!(1.152921504606847e40);
120     assert_eq!(f64::from_bits(0x4850F0CF064DD592), 2.305843009213694e40);
121     check!(2.305843009213694e40);
122 }
123 
124 #[test]
test_output_length()125 fn test_output_length() {
126     check!(1.0); // already tested in Basic
127     check!(1.2);
128     check!(1.23);
129     check!(1.234);
130     check!(1.2345);
131     check!(1.23456);
132     check!(1.234567);
133     check!(1.2345678); // already tested in Regression
134     check!(1.23456789);
135     check!(1.234567895); // 1.234567890 would be trimmed
136     check!(1.2345678901);
137     check!(1.23456789012);
138     check!(1.234567890123);
139     check!(1.2345678901234);
140     check!(1.23456789012345);
141     check!(1.234567890123456);
142     check!(1.2345678901234567);
143 
144     // Test 32-bit chunking
145     check!(4.294967294); // 2^32 - 2
146     check!(4.294967295); // 2^32 - 1
147     check!(4.294967296); // 2^32
148     check!(4.294967297); // 2^32 + 1
149     check!(4.294967298); // 2^32 + 2
150 }
151 
152 // Test min, max shift values in shiftright128
153 #[test]
test_min_max_shift()154 fn test_min_max_shift() {
155     let max_mantissa = (1u64 << 53) - 1;
156 
157     // 32-bit opt-size=0:  49 <= dist <= 50
158     // 32-bit opt-size=1:  30 <= dist <= 50
159     // 64-bit opt-size=0:  50 <= dist <= 50
160     // 64-bit opt-size=1:  30 <= dist <= 50
161     assert_eq!(1.7800590868057611E-307, ieee_parts_to_double(false, 4, 0));
162     check!(1.7800590868057611e-307);
163     // 32-bit opt-size=0:  49 <= dist <= 49
164     // 32-bit opt-size=1:  28 <= dist <= 49
165     // 64-bit opt-size=0:  50 <= dist <= 50
166     // 64-bit opt-size=1:  28 <= dist <= 50
167     assert_eq!(
168         2.8480945388892175E-306,
169         ieee_parts_to_double(false, 6, max_mantissa)
170     );
171     check!(2.8480945388892175e-306);
172     // 32-bit opt-size=0:  52 <= dist <= 53
173     // 32-bit opt-size=1:   2 <= dist <= 53
174     // 64-bit opt-size=0:  53 <= dist <= 53
175     // 64-bit opt-size=1:   2 <= dist <= 53
176     assert_eq!(2.446494580089078E-296, ieee_parts_to_double(false, 41, 0));
177     check!(2.446494580089078e-296);
178     // 32-bit opt-size=0:  52 <= dist <= 52
179     // 32-bit opt-size=1:   2 <= dist <= 52
180     // 64-bit opt-size=0:  53 <= dist <= 53
181     // 64-bit opt-size=1:   2 <= dist <= 53
182     assert_eq!(
183         4.8929891601781557E-296,
184         ieee_parts_to_double(false, 40, max_mantissa)
185     );
186     check!(4.8929891601781557e-296);
187 
188     // 32-bit opt-size=0:  57 <= dist <= 58
189     // 32-bit opt-size=1:  57 <= dist <= 58
190     // 64-bit opt-size=0:  58 <= dist <= 58
191     // 64-bit opt-size=1:  58 <= dist <= 58
192     assert_eq!(1.8014398509481984E16, ieee_parts_to_double(false, 1077, 0));
193     check!(1.8014398509481984e16);
194     // 32-bit opt-size=0:  57 <= dist <= 57
195     // 32-bit opt-size=1:  57 <= dist <= 57
196     // 64-bit opt-size=0:  58 <= dist <= 58
197     // 64-bit opt-size=1:  58 <= dist <= 58
198     assert_eq!(
199         3.6028797018963964E16,
200         ieee_parts_to_double(false, 1076, max_mantissa)
201     );
202     check!(3.6028797018963964e16);
203     // 32-bit opt-size=0:  51 <= dist <= 52
204     // 32-bit opt-size=1:  51 <= dist <= 59
205     // 64-bit opt-size=0:  52 <= dist <= 52
206     // 64-bit opt-size=1:  52 <= dist <= 59
207     assert_eq!(2.900835519859558E-216, ieee_parts_to_double(false, 307, 0));
208     check!(2.900835519859558e-216);
209     // 32-bit opt-size=0:  51 <= dist <= 51
210     // 32-bit opt-size=1:  51 <= dist <= 59
211     // 64-bit opt-size=0:  52 <= dist <= 52
212     // 64-bit opt-size=1:  52 <= dist <= 59
213     assert_eq!(
214         5.801671039719115E-216,
215         ieee_parts_to_double(false, 306, max_mantissa)
216     );
217     check!(5.801671039719115e-216);
218 
219     // https://github.com/ulfjack/ryu/commit/19e44d16d80236f5de25800f56d82606d1be00b9#commitcomment-30146483
220     // 32-bit opt-size=0:  49 <= dist <= 49
221     // 32-bit opt-size=1:  44 <= dist <= 49
222     // 64-bit opt-size=0:  50 <= dist <= 50
223     // 64-bit opt-size=1:  44 <= dist <= 50
224     assert_eq!(
225         3.196104012172126E-27,
226         ieee_parts_to_double(false, 934, 0x000FA7161A4D6E0C)
227     );
228     check!(3.196104012172126e-27);
229 }
230 
231 #[test]
test_small_integers()232 fn test_small_integers() {
233     check!(9007199254740991.0); // 2^53-1
234     check!(9007199254740992.0); // 2^53
235 
236     check!(1.0);
237     check!(12.0);
238     check!(123.0);
239     check!(1234.0);
240     check!(12345.0);
241     check!(123456.0);
242     check!(1234567.0);
243     check!(12345678.0);
244     check!(123456789.0);
245     check!(1234567890.0);
246     check!(1234567895.0);
247     check!(12345678901.0);
248     check!(123456789012.0);
249     check!(1234567890123.0);
250     check!(12345678901234.0);
251     check!(123456789012345.0);
252     check!(1234567890123456.0);
253 
254     // 10^i
255     check!(1.0);
256     check!(10.0);
257     check!(100.0);
258     check!(1000.0);
259     check!(10000.0);
260     check!(100000.0);
261     check!(1000000.0);
262     check!(10000000.0);
263     check!(100000000.0);
264     check!(1000000000.0);
265     check!(10000000000.0);
266     check!(100000000000.0);
267     check!(1000000000000.0);
268     check!(10000000000000.0);
269     check!(100000000000000.0);
270     check!(1000000000000000.0);
271 
272     // 10^15 + 10^i
273     check!(1000000000000001.0);
274     check!(1000000000000010.0);
275     check!(1000000000000100.0);
276     check!(1000000000001000.0);
277     check!(1000000000010000.0);
278     check!(1000000000100000.0);
279     check!(1000000001000000.0);
280     check!(1000000010000000.0);
281     check!(1000000100000000.0);
282     check!(1000001000000000.0);
283     check!(1000010000000000.0);
284     check!(1000100000000000.0);
285     check!(1001000000000000.0);
286     check!(1010000000000000.0);
287     check!(1100000000000000.0);
288 
289     // Largest power of 2 <= 10^(i+1)
290     check!(8.0);
291     check!(64.0);
292     check!(512.0);
293     check!(8192.0);
294     check!(65536.0);
295     check!(524288.0);
296     check!(8388608.0);
297     check!(67108864.0);
298     check!(536870912.0);
299     check!(8589934592.0);
300     check!(68719476736.0);
301     check!(549755813888.0);
302     check!(8796093022208.0);
303     check!(70368744177664.0);
304     check!(562949953421312.0);
305     check!(9007199254740992.0);
306 
307     // 1000 * (Largest power of 2 <= 10^(i+1))
308     check!(8000.0);
309     check!(64000.0);
310     check!(512000.0);
311     check!(8192000.0);
312     check!(65536000.0);
313     check!(524288000.0);
314     check!(8388608000.0);
315     check!(67108864000.0);
316     check!(536870912000.0);
317     check!(8589934592000.0);
318     check!(68719476736000.0);
319     check!(549755813888000.0);
320     check!(8796093022208000.0);
321 }
322