Yi Kong | ce81bb6 | 2020-08-31 01:21:33 +0800 | [diff] [blame^] | 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 | #[macro_use] |
| 22 | mod macros; |
| 23 | |
| 24 | use std::f64; |
| 25 | |
| 26 | fn pretty(f: f64) -> String { |
| 27 | ryu::Buffer::new().format(f).to_owned() |
| 28 | } |
| 29 | |
| 30 | fn ieee_parts_to_double(sign: bool, ieee_exponent: u32, ieee_mantissa: u64) -> f64 { |
| 31 | assert!(ieee_exponent <= 2047); |
| 32 | assert!(ieee_mantissa <= (1u64 << 53) - 1); |
| 33 | f64::from_bits(((sign as u64) << 63) | ((ieee_exponent as u64) << 52) | ieee_mantissa) |
| 34 | } |
| 35 | |
| 36 | #[test] |
| 37 | fn test_ryu() { |
| 38 | check!(0.3); |
| 39 | check!(1234000000000000.0); |
| 40 | check!(1.234e16); |
| 41 | check!(2.71828); |
| 42 | check!(1.1e128); |
| 43 | check!(1.1e-64); |
| 44 | check!(2.718281828459045); |
| 45 | check!(5e-324); |
| 46 | check!(1.7976931348623157e308); |
| 47 | } |
| 48 | |
| 49 | #[test] |
| 50 | fn test_random() { |
| 51 | let n = if cfg!(miri) { 100 } else { 1000000 }; |
| 52 | let mut buffer = ryu::Buffer::new(); |
| 53 | for _ in 0..n { |
| 54 | let f: f64 = rand::random(); |
| 55 | assert_eq!(f, buffer.format_finite(f).parse().unwrap()); |
| 56 | } |
| 57 | } |
| 58 | |
| 59 | #[test] |
| 60 | #[cfg_attr(miri, ignore)] |
| 61 | fn test_non_finite() { |
| 62 | for i in 0u64..1 << 23 { |
| 63 | let f = f64::from_bits((((1 << 11) - 1) << 52) + (i << 29)); |
| 64 | assert!(!f.is_finite(), "f={}", f); |
| 65 | ryu::Buffer::new().format_finite(f); |
| 66 | } |
| 67 | } |
| 68 | |
| 69 | #[test] |
| 70 | fn test_basic() { |
| 71 | check!(0.0); |
| 72 | check!(-0.0); |
| 73 | check!(1.0); |
| 74 | check!(-1.0); |
| 75 | assert_eq!(pretty(f64::NAN), "NaN"); |
| 76 | assert_eq!(pretty(f64::INFINITY), "inf"); |
| 77 | assert_eq!(pretty(f64::NEG_INFINITY), "-inf"); |
| 78 | } |
| 79 | |
| 80 | #[test] |
| 81 | fn test_switch_to_subnormal() { |
| 82 | check!(2.2250738585072014e-308); |
| 83 | } |
| 84 | |
| 85 | #[test] |
| 86 | fn test_min_and_max() { |
| 87 | assert_eq!(f64::from_bits(0x7fefffffffffffff), 1.7976931348623157e308); |
| 88 | check!(1.7976931348623157e308); |
| 89 | assert_eq!(f64::from_bits(1), 5e-324); |
| 90 | check!(5e-324); |
| 91 | } |
| 92 | |
| 93 | #[test] |
| 94 | fn test_lots_of_trailing_zeros() { |
| 95 | check!(2.9802322387695312e-8); |
| 96 | } |
| 97 | |
| 98 | #[test] |
| 99 | fn test_regression() { |
| 100 | check!(-2.109808898695963e16); |
| 101 | check!(4.940656e-318); |
| 102 | check!(1.18575755e-316); |
| 103 | check!(2.989102097996e-312); |
| 104 | check!(9060801153433600.0); |
| 105 | check!(4.708356024711512e18); |
| 106 | check!(9.409340012568248e18); |
| 107 | check!(1.2345678); |
| 108 | } |
| 109 | |
| 110 | #[test] |
| 111 | fn test_looks_like_pow5() { |
| 112 | // These numbers have a mantissa that is a multiple of the largest power of |
| 113 | // 5 that fits, and an exponent that causes the computation for q to result |
| 114 | // in 22, which is a corner case for Ryƫ. |
| 115 | assert_eq!(f64::from_bits(0x4830F0CF064DD592), 5.764607523034235e39); |
| 116 | check!(5.764607523034235e39); |
| 117 | assert_eq!(f64::from_bits(0x4840F0CF064DD592), 1.152921504606847e40); |
| 118 | check!(1.152921504606847e40); |
| 119 | assert_eq!(f64::from_bits(0x4850F0CF064DD592), 2.305843009213694e40); |
| 120 | check!(2.305843009213694e40); |
| 121 | } |
| 122 | |
| 123 | #[test] |
| 124 | fn test_output_length() { |
| 125 | check!(1.0); // already tested in Basic |
| 126 | check!(1.2); |
| 127 | check!(1.23); |
| 128 | check!(1.234); |
| 129 | check!(1.2345); |
| 130 | check!(1.23456); |
| 131 | check!(1.234567); |
| 132 | check!(1.2345678); // already tested in Regression |
| 133 | check!(1.23456789); |
| 134 | check!(1.234567895); // 1.234567890 would be trimmed |
| 135 | check!(1.2345678901); |
| 136 | check!(1.23456789012); |
| 137 | check!(1.234567890123); |
| 138 | check!(1.2345678901234); |
| 139 | check!(1.23456789012345); |
| 140 | check!(1.234567890123456); |
| 141 | check!(1.2345678901234567); |
| 142 | |
| 143 | // Test 32-bit chunking |
| 144 | check!(4.294967294); // 2^32 - 2 |
| 145 | check!(4.294967295); // 2^32 - 1 |
| 146 | check!(4.294967296); // 2^32 |
| 147 | check!(4.294967297); // 2^32 + 1 |
| 148 | check!(4.294967298); // 2^32 + 2 |
| 149 | } |
| 150 | |
| 151 | // Test min, max shift values in shiftright128 |
| 152 | #[test] |
| 153 | fn test_min_max_shift() { |
| 154 | let max_mantissa = (1u64 << 53) - 1; |
| 155 | |
| 156 | // 32-bit opt-size=0: 49 <= dist <= 50 |
| 157 | // 32-bit opt-size=1: 30 <= dist <= 50 |
| 158 | // 64-bit opt-size=0: 50 <= dist <= 50 |
| 159 | // 64-bit opt-size=1: 30 <= dist <= 50 |
| 160 | assert_eq!(1.7800590868057611E-307, ieee_parts_to_double(false, 4, 0)); |
| 161 | check!(1.7800590868057611e-307); |
| 162 | // 32-bit opt-size=0: 49 <= dist <= 49 |
| 163 | // 32-bit opt-size=1: 28 <= dist <= 49 |
| 164 | // 64-bit opt-size=0: 50 <= dist <= 50 |
| 165 | // 64-bit opt-size=1: 28 <= dist <= 50 |
| 166 | assert_eq!( |
| 167 | 2.8480945388892175E-306, |
| 168 | ieee_parts_to_double(false, 6, max_mantissa) |
| 169 | ); |
| 170 | check!(2.8480945388892175e-306); |
| 171 | // 32-bit opt-size=0: 52 <= dist <= 53 |
| 172 | // 32-bit opt-size=1: 2 <= dist <= 53 |
| 173 | // 64-bit opt-size=0: 53 <= dist <= 53 |
| 174 | // 64-bit opt-size=1: 2 <= dist <= 53 |
| 175 | assert_eq!(2.446494580089078E-296, ieee_parts_to_double(false, 41, 0)); |
| 176 | check!(2.446494580089078e-296); |
| 177 | // 32-bit opt-size=0: 52 <= dist <= 52 |
| 178 | // 32-bit opt-size=1: 2 <= dist <= 52 |
| 179 | // 64-bit opt-size=0: 53 <= dist <= 53 |
| 180 | // 64-bit opt-size=1: 2 <= dist <= 53 |
| 181 | assert_eq!( |
| 182 | 4.8929891601781557E-296, |
| 183 | ieee_parts_to_double(false, 40, max_mantissa) |
| 184 | ); |
| 185 | check!(4.8929891601781557e-296); |
| 186 | |
| 187 | // 32-bit opt-size=0: 57 <= dist <= 58 |
| 188 | // 32-bit opt-size=1: 57 <= dist <= 58 |
| 189 | // 64-bit opt-size=0: 58 <= dist <= 58 |
| 190 | // 64-bit opt-size=1: 58 <= dist <= 58 |
| 191 | assert_eq!(1.8014398509481984E16, ieee_parts_to_double(false, 1077, 0)); |
| 192 | check!(1.8014398509481984e16); |
| 193 | // 32-bit opt-size=0: 57 <= dist <= 57 |
| 194 | // 32-bit opt-size=1: 57 <= dist <= 57 |
| 195 | // 64-bit opt-size=0: 58 <= dist <= 58 |
| 196 | // 64-bit opt-size=1: 58 <= dist <= 58 |
| 197 | assert_eq!( |
| 198 | 3.6028797018963964E16, |
| 199 | ieee_parts_to_double(false, 1076, max_mantissa) |
| 200 | ); |
| 201 | check!(3.6028797018963964e16); |
| 202 | // 32-bit opt-size=0: 51 <= dist <= 52 |
| 203 | // 32-bit opt-size=1: 51 <= dist <= 59 |
| 204 | // 64-bit opt-size=0: 52 <= dist <= 52 |
| 205 | // 64-bit opt-size=1: 52 <= dist <= 59 |
| 206 | assert_eq!(2.900835519859558E-216, ieee_parts_to_double(false, 307, 0)); |
| 207 | check!(2.900835519859558e-216); |
| 208 | // 32-bit opt-size=0: 51 <= dist <= 51 |
| 209 | // 32-bit opt-size=1: 51 <= dist <= 59 |
| 210 | // 64-bit opt-size=0: 52 <= dist <= 52 |
| 211 | // 64-bit opt-size=1: 52 <= dist <= 59 |
| 212 | assert_eq!( |
| 213 | 5.801671039719115E-216, |
| 214 | ieee_parts_to_double(false, 306, max_mantissa) |
| 215 | ); |
| 216 | check!(5.801671039719115e-216); |
| 217 | |
| 218 | // https://github.com/ulfjack/ryu/commit/19e44d16d80236f5de25800f56d82606d1be00b9#commitcomment-30146483 |
| 219 | // 32-bit opt-size=0: 49 <= dist <= 49 |
| 220 | // 32-bit opt-size=1: 44 <= dist <= 49 |
| 221 | // 64-bit opt-size=0: 50 <= dist <= 50 |
| 222 | // 64-bit opt-size=1: 44 <= dist <= 50 |
| 223 | assert_eq!( |
| 224 | 3.196104012172126E-27, |
| 225 | ieee_parts_to_double(false, 934, 0x000FA7161A4D6E0C) |
| 226 | ); |
| 227 | check!(3.196104012172126e-27); |
| 228 | } |
| 229 | |
| 230 | #[test] |
| 231 | fn test_small_integers() { |
| 232 | check!(9007199254740991.0); // 2^53-1 |
| 233 | check!(9007199254740992.0); // 2^53 |
| 234 | |
| 235 | check!(1.0); |
| 236 | check!(12.0); |
| 237 | check!(123.0); |
| 238 | check!(1234.0); |
| 239 | check!(12345.0); |
| 240 | check!(123456.0); |
| 241 | check!(1234567.0); |
| 242 | check!(12345678.0); |
| 243 | check!(123456789.0); |
| 244 | check!(1234567890.0); |
| 245 | check!(1234567895.0); |
| 246 | check!(12345678901.0); |
| 247 | check!(123456789012.0); |
| 248 | check!(1234567890123.0); |
| 249 | check!(12345678901234.0); |
| 250 | check!(123456789012345.0); |
| 251 | check!(1234567890123456.0); |
| 252 | |
| 253 | // 10^i |
| 254 | check!(1.0); |
| 255 | check!(10.0); |
| 256 | check!(100.0); |
| 257 | check!(1000.0); |
| 258 | check!(10000.0); |
| 259 | check!(100000.0); |
| 260 | check!(1000000.0); |
| 261 | check!(10000000.0); |
| 262 | check!(100000000.0); |
| 263 | check!(1000000000.0); |
| 264 | check!(10000000000.0); |
| 265 | check!(100000000000.0); |
| 266 | check!(1000000000000.0); |
| 267 | check!(10000000000000.0); |
| 268 | check!(100000000000000.0); |
| 269 | check!(1000000000000000.0); |
| 270 | |
| 271 | // 10^15 + 10^i |
| 272 | check!(1000000000000001.0); |
| 273 | check!(1000000000000010.0); |
| 274 | check!(1000000000000100.0); |
| 275 | check!(1000000000001000.0); |
| 276 | check!(1000000000010000.0); |
| 277 | check!(1000000000100000.0); |
| 278 | check!(1000000001000000.0); |
| 279 | check!(1000000010000000.0); |
| 280 | check!(1000000100000000.0); |
| 281 | check!(1000001000000000.0); |
| 282 | check!(1000010000000000.0); |
| 283 | check!(1000100000000000.0); |
| 284 | check!(1001000000000000.0); |
| 285 | check!(1010000000000000.0); |
| 286 | check!(1100000000000000.0); |
| 287 | |
| 288 | // Largest power of 2 <= 10^(i+1) |
| 289 | check!(8.0); |
| 290 | check!(64.0); |
| 291 | check!(512.0); |
| 292 | check!(8192.0); |
| 293 | check!(65536.0); |
| 294 | check!(524288.0); |
| 295 | check!(8388608.0); |
| 296 | check!(67108864.0); |
| 297 | check!(536870912.0); |
| 298 | check!(8589934592.0); |
| 299 | check!(68719476736.0); |
| 300 | check!(549755813888.0); |
| 301 | check!(8796093022208.0); |
| 302 | check!(70368744177664.0); |
| 303 | check!(562949953421312.0); |
| 304 | check!(9007199254740992.0); |
| 305 | |
| 306 | // 1000 * (Largest power of 2 <= 10^(i+1)) |
| 307 | check!(8000.0); |
| 308 | check!(64000.0); |
| 309 | check!(512000.0); |
| 310 | check!(8192000.0); |
| 311 | check!(65536000.0); |
| 312 | check!(524288000.0); |
| 313 | check!(8388608000.0); |
| 314 | check!(67108864000.0); |
| 315 | check!(536870912000.0); |
| 316 | check!(8589934592000.0); |
| 317 | check!(68719476736000.0); |
| 318 | check!(549755813888000.0); |
| 319 | check!(8796093022208000.0); |
| 320 | } |