1 // Copyright 2009 The Go Authors. All rights reserved. 2 // Use of this source code is governed by a BSD-style 3 // license that can be found in the LICENSE file. 4 5 package strconv_test 6 7 import ( 8 "math" 9 "math/rand" 10 "reflect" 11 . "strconv" 12 "strings" 13 "sync" 14 "testing" 15 "time" 16 ) 17 18 type atofTest struct { 19 in string 20 out string 21 err error 22 } 23 24 var atoftests = []atofTest{ 25 {"", "0", ErrSyntax}, 26 {"1", "1", nil}, 27 {"+1", "1", nil}, 28 {"1x", "0", ErrSyntax}, 29 {"1.1.", "0", ErrSyntax}, 30 {"1e23", "1e+23", nil}, 31 {"1E23", "1e+23", nil}, 32 {"100000000000000000000000", "1e+23", nil}, 33 {"1e-100", "1e-100", nil}, 34 {"123456700", "1.234567e+08", nil}, 35 {"99999999999999974834176", "9.999999999999997e+22", nil}, 36 {"100000000000000000000001", "1.0000000000000001e+23", nil}, 37 {"100000000000000008388608", "1.0000000000000001e+23", nil}, 38 {"100000000000000016777215", "1.0000000000000001e+23", nil}, 39 {"100000000000000016777216", "1.0000000000000003e+23", nil}, 40 {"-1", "-1", nil}, 41 {"-0.1", "-0.1", nil}, 42 {"-0", "-0", nil}, 43 {"1e-20", "1e-20", nil}, 44 {"625e-3", "0.625", nil}, 45 46 // Hexadecimal floating-point. 47 {"0x1p0", "1", nil}, 48 {"0x1p1", "2", nil}, 49 {"0x1p-1", "0.5", nil}, 50 {"0x1ep-1", "15", nil}, 51 {"-0x1ep-1", "-15", nil}, 52 {"-0x1_ep-1", "-15", nil}, 53 {"0x1p-200", "6.223015277861142e-61", nil}, 54 {"0x1p200", "1.6069380442589903e+60", nil}, 55 {"0x1fFe2.p0", "131042", nil}, 56 {"0x1fFe2.P0", "131042", nil}, 57 {"-0x2p3", "-16", nil}, 58 {"0x0.fp4", "15", nil}, 59 {"0x0.fp0", "0.9375", nil}, 60 {"0x1e2", "0", ErrSyntax}, 61 {"1p2", "0", ErrSyntax}, 62 63 // zeros 64 {"0", "0", nil}, 65 {"0e0", "0", nil}, 66 {"-0e0", "-0", nil}, 67 {"+0e0", "0", nil}, 68 {"0e-0", "0", nil}, 69 {"-0e-0", "-0", nil}, 70 {"+0e-0", "0", nil}, 71 {"0e+0", "0", nil}, 72 {"-0e+0", "-0", nil}, 73 {"+0e+0", "0", nil}, 74 {"0e+01234567890123456789", "0", nil}, 75 {"0.00e-01234567890123456789", "0", nil}, 76 {"-0e+01234567890123456789", "-0", nil}, 77 {"-0.00e-01234567890123456789", "-0", nil}, 78 {"0x0p+01234567890123456789", "0", nil}, 79 {"0x0.00p-01234567890123456789", "0", nil}, 80 {"-0x0p+01234567890123456789", "-0", nil}, 81 {"-0x0.00p-01234567890123456789", "-0", nil}, 82 83 {"0e291", "0", nil}, // issue 15364 84 {"0e292", "0", nil}, // issue 15364 85 {"0e347", "0", nil}, // issue 15364 86 {"0e348", "0", nil}, // issue 15364 87 {"-0e291", "-0", nil}, 88 {"-0e292", "-0", nil}, 89 {"-0e347", "-0", nil}, 90 {"-0e348", "-0", nil}, 91 {"0x0p126", "0", nil}, 92 {"0x0p127", "0", nil}, 93 {"0x0p128", "0", nil}, 94 {"0x0p129", "0", nil}, 95 {"0x0p130", "0", nil}, 96 {"0x0p1022", "0", nil}, 97 {"0x0p1023", "0", nil}, 98 {"0x0p1024", "0", nil}, 99 {"0x0p1025", "0", nil}, 100 {"0x0p1026", "0", nil}, 101 {"-0x0p126", "-0", nil}, 102 {"-0x0p127", "-0", nil}, 103 {"-0x0p128", "-0", nil}, 104 {"-0x0p129", "-0", nil}, 105 {"-0x0p130", "-0", nil}, 106 {"-0x0p1022", "-0", nil}, 107 {"-0x0p1023", "-0", nil}, 108 {"-0x0p1024", "-0", nil}, 109 {"-0x0p1025", "-0", nil}, 110 {"-0x0p1026", "-0", nil}, 111 112 // NaNs 113 {"nan", "NaN", nil}, 114 {"NaN", "NaN", nil}, 115 {"NAN", "NaN", nil}, 116 117 // Infs 118 {"inf", "+Inf", nil}, 119 {"-Inf", "-Inf", nil}, 120 {"+INF", "+Inf", nil}, 121 {"-Infinity", "-Inf", nil}, 122 {"+INFINITY", "+Inf", nil}, 123 {"Infinity", "+Inf", nil}, 124 125 // largest float64 126 {"1.7976931348623157e308", "1.7976931348623157e+308", nil}, 127 {"-1.7976931348623157e308", "-1.7976931348623157e+308", nil}, 128 {"0x1.fffffffffffffp1023", "1.7976931348623157e+308", nil}, 129 {"-0x1.fffffffffffffp1023", "-1.7976931348623157e+308", nil}, 130 {"0x1fffffffffffffp+971", "1.7976931348623157e+308", nil}, 131 {"-0x1fffffffffffffp+971", "-1.7976931348623157e+308", nil}, 132 {"0x.1fffffffffffffp1027", "1.7976931348623157e+308", nil}, 133 {"-0x.1fffffffffffffp1027", "-1.7976931348623157e+308", nil}, 134 135 // next float64 - too large 136 {"1.7976931348623159e308", "+Inf", ErrRange}, 137 {"-1.7976931348623159e308", "-Inf", ErrRange}, 138 {"0x1p1024", "+Inf", ErrRange}, 139 {"-0x1p1024", "-Inf", ErrRange}, 140 {"0x2p1023", "+Inf", ErrRange}, 141 {"-0x2p1023", "-Inf", ErrRange}, 142 {"0x.1p1028", "+Inf", ErrRange}, 143 {"-0x.1p1028", "-Inf", ErrRange}, 144 {"0x.2p1027", "+Inf", ErrRange}, 145 {"-0x.2p1027", "-Inf", ErrRange}, 146 147 // the border is ...158079 148 // borderline - okay 149 {"1.7976931348623158e308", "1.7976931348623157e+308", nil}, 150 {"-1.7976931348623158e308", "-1.7976931348623157e+308", nil}, 151 {"0x1.fffffffffffff7fffp1023", "1.7976931348623157e+308", nil}, 152 {"-0x1.fffffffffffff7fffp1023", "-1.7976931348623157e+308", nil}, 153 // borderline - too large 154 {"1.797693134862315808e308", "+Inf", ErrRange}, 155 {"-1.797693134862315808e308", "-Inf", ErrRange}, 156 {"0x1.fffffffffffff8p1023", "+Inf", ErrRange}, 157 {"-0x1.fffffffffffff8p1023", "-Inf", ErrRange}, 158 {"0x1fffffffffffff.8p+971", "+Inf", ErrRange}, 159 {"-0x1fffffffffffff8p+967", "-Inf", ErrRange}, 160 {"0x.1fffffffffffff8p1027", "+Inf", ErrRange}, 161 {"-0x.1fffffffffffff9p1027", "-Inf", ErrRange}, 162 163 // a little too large 164 {"1e308", "1e+308", nil}, 165 {"2e308", "+Inf", ErrRange}, 166 {"1e309", "+Inf", ErrRange}, 167 {"0x1p1025", "+Inf", ErrRange}, 168 169 // way too large 170 {"1e310", "+Inf", ErrRange}, 171 {"-1e310", "-Inf", ErrRange}, 172 {"1e400", "+Inf", ErrRange}, 173 {"-1e400", "-Inf", ErrRange}, 174 {"1e400000", "+Inf", ErrRange}, 175 {"-1e400000", "-Inf", ErrRange}, 176 {"0x1p1030", "+Inf", ErrRange}, 177 {"0x1p2000", "+Inf", ErrRange}, 178 {"0x1p2000000000", "+Inf", ErrRange}, 179 {"-0x1p1030", "-Inf", ErrRange}, 180 {"-0x1p2000", "-Inf", ErrRange}, 181 {"-0x1p2000000000", "-Inf", ErrRange}, 182 183 // denormalized 184 {"1e-305", "1e-305", nil}, 185 {"1e-306", "1e-306", nil}, 186 {"1e-307", "1e-307", nil}, 187 {"1e-308", "1e-308", nil}, 188 {"1e-309", "1e-309", nil}, 189 {"1e-310", "1e-310", nil}, 190 {"1e-322", "1e-322", nil}, 191 // smallest denormal 192 {"5e-324", "5e-324", nil}, 193 {"4e-324", "5e-324", nil}, 194 {"3e-324", "5e-324", nil}, 195 // too small 196 {"2e-324", "0", nil}, 197 // way too small 198 {"1e-350", "0", nil}, 199 {"1e-400000", "0", nil}, 200 201 // Near denormals and denormals. 202 {"0x2.00000000000000p-1010", "1.8227805048890994e-304", nil}, // 0x00e0000000000000 203 {"0x1.fffffffffffff0p-1010", "1.8227805048890992e-304", nil}, // 0x00dfffffffffffff 204 {"0x1.fffffffffffff7p-1010", "1.8227805048890992e-304", nil}, // rounded down 205 {"0x1.fffffffffffff8p-1010", "1.8227805048890994e-304", nil}, // rounded up 206 {"0x1.fffffffffffff9p-1010", "1.8227805048890994e-304", nil}, // rounded up 207 208 {"0x2.00000000000000p-1022", "4.450147717014403e-308", nil}, // 0x0020000000000000 209 {"0x1.fffffffffffff0p-1022", "4.4501477170144023e-308", nil}, // 0x001fffffffffffff 210 {"0x1.fffffffffffff7p-1022", "4.4501477170144023e-308", nil}, // rounded down 211 {"0x1.fffffffffffff8p-1022", "4.450147717014403e-308", nil}, // rounded up 212 {"0x1.fffffffffffff9p-1022", "4.450147717014403e-308", nil}, // rounded up 213 214 {"0x1.00000000000000p-1022", "2.2250738585072014e-308", nil}, // 0x0010000000000000 215 {"0x0.fffffffffffff0p-1022", "2.225073858507201e-308", nil}, // 0x000fffffffffffff 216 {"0x0.ffffffffffffe0p-1022", "2.2250738585072004e-308", nil}, // 0x000ffffffffffffe 217 {"0x0.ffffffffffffe7p-1022", "2.2250738585072004e-308", nil}, // rounded down 218 {"0x1.ffffffffffffe8p-1023", "2.225073858507201e-308", nil}, // rounded up 219 {"0x1.ffffffffffffe9p-1023", "2.225073858507201e-308", nil}, // rounded up 220 221 {"0x0.00000003fffff0p-1022", "2.072261e-317", nil}, // 0x00000000003fffff 222 {"0x0.00000003456780p-1022", "1.694649e-317", nil}, // 0x0000000000345678 223 {"0x0.00000003456787p-1022", "1.694649e-317", nil}, // rounded down 224 {"0x0.00000003456788p-1022", "1.694649e-317", nil}, // rounded down (half to even) 225 {"0x0.00000003456790p-1022", "1.6946496e-317", nil}, // 0x0000000000345679 226 {"0x0.00000003456789p-1022", "1.6946496e-317", nil}, // rounded up 227 228 {"0x0.0000000345678800000000000000000000000001p-1022", "1.6946496e-317", nil}, // rounded up 229 230 {"0x0.000000000000f0p-1022", "7.4e-323", nil}, // 0x000000000000000f 231 {"0x0.00000000000060p-1022", "3e-323", nil}, // 0x0000000000000006 232 {"0x0.00000000000058p-1022", "3e-323", nil}, // rounded up 233 {"0x0.00000000000057p-1022", "2.5e-323", nil}, // rounded down 234 {"0x0.00000000000050p-1022", "2.5e-323", nil}, // 0x0000000000000005 235 236 {"0x0.00000000000010p-1022", "5e-324", nil}, // 0x0000000000000001 237 {"0x0.000000000000081p-1022", "5e-324", nil}, // rounded up 238 {"0x0.00000000000008p-1022", "0", nil}, // rounded down 239 {"0x0.00000000000007fp-1022", "0", nil}, // rounded down 240 241 // try to overflow exponent 242 {"1e-4294967296", "0", nil}, 243 {"1e+4294967296", "+Inf", ErrRange}, 244 {"1e-18446744073709551616", "0", nil}, 245 {"1e+18446744073709551616", "+Inf", ErrRange}, 246 {"0x1p-4294967296", "0", nil}, 247 {"0x1p+4294967296", "+Inf", ErrRange}, 248 {"0x1p-18446744073709551616", "0", nil}, 249 {"0x1p+18446744073709551616", "+Inf", ErrRange}, 250 251 // Parse errors 252 {"1e", "0", ErrSyntax}, 253 {"1e-", "0", ErrSyntax}, 254 {".e-1", "0", ErrSyntax}, 255 {"1\x00.2", "0", ErrSyntax}, 256 {"0x", "0", ErrSyntax}, 257 {"0x.", "0", ErrSyntax}, 258 {"0x1", "0", ErrSyntax}, 259 {"0x.1", "0", ErrSyntax}, 260 {"0x1p", "0", ErrSyntax}, 261 {"0x.1p", "0", ErrSyntax}, 262 {"0x1p+", "0", ErrSyntax}, 263 {"0x.1p+", "0", ErrSyntax}, 264 {"0x1p-", "0", ErrSyntax}, 265 {"0x.1p-", "0", ErrSyntax}, 266 {"0x1p+2", "4", nil}, 267 {"0x.1p+2", "0.25", nil}, 268 {"0x1p-2", "0.25", nil}, 269 {"0x.1p-2", "0.015625", nil}, 270 271 // https://www.exploringbinary.com/java-hangs-when-converting-2-2250738585072012e-308/ 272 {"2.2250738585072012e-308", "2.2250738585072014e-308", nil}, 273 // https://www.exploringbinary.com/php-hangs-on-numeric-value-2-2250738585072011e-308/ 274 {"2.2250738585072011e-308", "2.225073858507201e-308", nil}, 275 276 // A very large number (initially wrongly parsed by the fast algorithm). 277 {"4.630813248087435e+307", "4.630813248087435e+307", nil}, 278 279 // A different kind of very large number. 280 {"22.222222222222222", "22.22222222222222", nil}, 281 {"2." + strings.Repeat("2", 4000) + "e+1", "22.22222222222222", nil}, 282 {"0x1.1111111111111p222", "7.18931911124017e+66", nil}, 283 {"0x2.2222222222222p221", "7.18931911124017e+66", nil}, 284 {"0x2." + strings.Repeat("2", 4000) + "p221", "7.18931911124017e+66", nil}, 285 286 // Exactly halfway between 1 and math.Nextafter(1, 2). 287 // Round to even (down). 288 {"1.00000000000000011102230246251565404236316680908203125", "1", nil}, 289 {"0x1.00000000000008p0", "1", nil}, 290 // Slightly lower; still round down. 291 {"1.00000000000000011102230246251565404236316680908203124", "1", nil}, 292 {"0x1.00000000000007Fp0", "1", nil}, 293 // Slightly higher; round up. 294 {"1.00000000000000011102230246251565404236316680908203126", "1.0000000000000002", nil}, 295 {"0x1.000000000000081p0", "1.0000000000000002", nil}, 296 {"0x1.00000000000009p0", "1.0000000000000002", nil}, 297 // Slightly higher, but you have to read all the way to the end. 298 {"1.00000000000000011102230246251565404236316680908203125" + strings.Repeat("0", 10000) + "1", "1.0000000000000002", nil}, 299 {"0x1.00000000000008" + strings.Repeat("0", 10000) + "1p0", "1.0000000000000002", nil}, 300 301 // Halfway between x := math.Nextafter(1, 2) and math.Nextafter(x, 2) 302 // Round to even (up). 303 {"1.00000000000000033306690738754696212708950042724609375", "1.0000000000000004", nil}, 304 {"0x1.00000000000018p0", "1.0000000000000004", nil}, 305 306 // Underscores. 307 {"1_23.50_0_0e+1_2", "1.235e+14", nil}, 308 {"-_123.5e+12", "0", ErrSyntax}, 309 {"+_123.5e+12", "0", ErrSyntax}, 310 {"_123.5e+12", "0", ErrSyntax}, 311 {"1__23.5e+12", "0", ErrSyntax}, 312 {"123_.5e+12", "0", ErrSyntax}, 313 {"123._5e+12", "0", ErrSyntax}, 314 {"123.5_e+12", "0", ErrSyntax}, 315 {"123.5__0e+12", "0", ErrSyntax}, 316 {"123.5e_+12", "0", ErrSyntax}, 317 {"123.5e+_12", "0", ErrSyntax}, 318 {"123.5e_-12", "0", ErrSyntax}, 319 {"123.5e-_12", "0", ErrSyntax}, 320 {"123.5e+1__2", "0", ErrSyntax}, 321 {"123.5e+12_", "0", ErrSyntax}, 322 323 {"0x_1_2.3_4_5p+1_2", "74565", nil}, 324 {"-_0x12.345p+12", "0", ErrSyntax}, 325 {"+_0x12.345p+12", "0", ErrSyntax}, 326 {"_0x12.345p+12", "0", ErrSyntax}, 327 {"0x__12.345p+12", "0", ErrSyntax}, 328 {"0x1__2.345p+12", "0", ErrSyntax}, 329 {"0x12_.345p+12", "0", ErrSyntax}, 330 {"0x12._345p+12", "0", ErrSyntax}, 331 {"0x12.3__45p+12", "0", ErrSyntax}, 332 {"0x12.345_p+12", "0", ErrSyntax}, 333 {"0x12.345p_+12", "0", ErrSyntax}, 334 {"0x12.345p+_12", "0", ErrSyntax}, 335 {"0x12.345p_-12", "0", ErrSyntax}, 336 {"0x12.345p-_12", "0", ErrSyntax}, 337 {"0x12.345p+1__2", "0", ErrSyntax}, 338 {"0x12.345p+12_", "0", ErrSyntax}, 339 } 340 341 var atof32tests = []atofTest{ 342 // Hex 343 {"0x1p-100", "7.888609e-31", nil}, 344 {"0x1p100", "1.2676506e+30", nil}, 345 346 // Exactly halfway between 1 and the next float32. 347 // Round to even (down). 348 {"1.000000059604644775390625", "1", nil}, 349 {"0x1.000001p0", "1", nil}, 350 // Slightly lower. 351 {"1.000000059604644775390624", "1", nil}, 352 {"0x1.0000008p0", "1", nil}, 353 {"0x1.000000fp0", "1", nil}, 354 // Slightly higher. 355 {"1.000000059604644775390626", "1.0000001", nil}, 356 {"0x1.000002p0", "1.0000001", nil}, 357 {"0x1.0000018p0", "1.0000001", nil}, 358 {"0x1.0000011p0", "1.0000001", nil}, 359 // Slightly higher, but you have to read all the way to the end. 360 {"1.000000059604644775390625" + strings.Repeat("0", 10000) + "1", "1.0000001", nil}, 361 {"0x1.000001" + strings.Repeat("0", 10000) + "1p0", "1.0000001", nil}, 362 363 // largest float32: (1<<128) * (1 - 2^-24) 364 {"340282346638528859811704183484516925440", "3.4028235e+38", nil}, 365 {"-340282346638528859811704183484516925440", "-3.4028235e+38", nil}, 366 {"0x.ffffffp128", "3.4028235e+38", nil}, 367 {"-340282346638528859811704183484516925440", "-3.4028235e+38", nil}, 368 {"-0x.ffffffp128", "-3.4028235e+38", nil}, 369 // next float32 - too large 370 {"3.4028236e38", "+Inf", ErrRange}, 371 {"-3.4028236e38", "-Inf", ErrRange}, 372 {"0x1.0p128", "+Inf", ErrRange}, 373 {"-0x1.0p128", "-Inf", ErrRange}, 374 // the border is 3.40282356779...e+38 375 // borderline - okay 376 {"3.402823567e38", "3.4028235e+38", nil}, 377 {"-3.402823567e38", "-3.4028235e+38", nil}, 378 {"0x.ffffff7fp128", "3.4028235e+38", nil}, 379 {"-0x.ffffff7fp128", "-3.4028235e+38", nil}, 380 // borderline - too large 381 {"3.4028235678e38", "+Inf", ErrRange}, 382 {"-3.4028235678e38", "-Inf", ErrRange}, 383 {"0x.ffffff8p128", "+Inf", ErrRange}, 384 {"-0x.ffffff8p128", "-Inf", ErrRange}, 385 386 // Denormals: less than 2^-126 387 {"1e-38", "1e-38", nil}, 388 {"1e-39", "1e-39", nil}, 389 {"1e-40", "1e-40", nil}, 390 {"1e-41", "1e-41", nil}, 391 {"1e-42", "1e-42", nil}, 392 {"1e-43", "1e-43", nil}, 393 {"1e-44", "1e-44", nil}, 394 {"6e-45", "6e-45", nil}, // 4p-149 = 5.6e-45 395 {"5e-45", "6e-45", nil}, 396 397 // Smallest denormal 398 {"1e-45", "1e-45", nil}, // 1p-149 = 1.4e-45 399 {"2e-45", "1e-45", nil}, 400 {"3e-45", "3e-45", nil}, 401 402 // Near denormals and denormals. 403 {"0x0.89aBcDp-125", "1.2643093e-38", nil}, // 0x0089abcd 404 {"0x0.8000000p-125", "1.1754944e-38", nil}, // 0x00800000 405 {"0x0.1234560p-125", "1.671814e-39", nil}, // 0x00123456 406 {"0x0.1234567p-125", "1.671814e-39", nil}, // rounded down 407 {"0x0.1234568p-125", "1.671814e-39", nil}, // rounded down 408 {"0x0.1234569p-125", "1.671815e-39", nil}, // rounded up 409 {"0x0.1234570p-125", "1.671815e-39", nil}, // 0x00123457 410 {"0x0.0000010p-125", "1e-45", nil}, // 0x00000001 411 {"0x0.00000081p-125", "1e-45", nil}, // rounded up 412 {"0x0.0000008p-125", "0", nil}, // rounded down 413 {"0x0.0000007p-125", "0", nil}, // rounded down 414 415 // 2^92 = 8388608p+69 = 4951760157141521099596496896 (4.9517602e27) 416 // is an exact power of two that needs 8 decimal digits to be correctly 417 // parsed back. 418 // The float32 before is 16777215p+68 = 4.95175986e+27 419 // The halfway is 4.951760009. A bad algorithm that thinks the previous 420 // float32 is 8388607p+69 will shorten incorrectly to 4.95176e+27. 421 {"4951760157141521099596496896", "4.9517602e+27", nil}, 422 } 423 424 type atofSimpleTest struct { 425 x float64 426 s string 427 } 428 429 var ( 430 atofOnce sync.Once 431 atofRandomTests []atofSimpleTest 432 benchmarksRandomBits [1024]string 433 benchmarksRandomNormal [1024]string 434 ) 435 436 func initAtof() { 437 atofOnce.Do(initAtofOnce) 438 } 439 440 func initAtofOnce() { 441 // The atof routines return NumErrors wrapping 442 // the error and the string. Convert the table above. 443 for i := range atoftests { 444 test := &atoftests[i] 445 if test.err != nil { 446 test.err = &NumError{"ParseFloat", test.in, test.err} 447 } 448 } 449 for i := range atof32tests { 450 test := &atof32tests[i] 451 if test.err != nil { 452 test.err = &NumError{"ParseFloat", test.in, test.err} 453 } 454 } 455 456 // Generate random inputs for tests and benchmarks 457 rand.Seed(time.Now().UnixNano()) 458 if testing.Short() { 459 atofRandomTests = make([]atofSimpleTest, 100) 460 } else { 461 atofRandomTests = make([]atofSimpleTest, 10000) 462 } 463 for i := range atofRandomTests { 464 n := uint64(rand.Uint32())<<32 | uint64(rand.Uint32()) 465 x := math.Float64frombits(n) 466 s := FormatFloat(x, 'g', -1, 64) 467 atofRandomTests[i] = atofSimpleTest{x, s} 468 } 469 470 for i := range benchmarksRandomBits { 471 bits := uint64(rand.Uint32())<<32 | uint64(rand.Uint32()) 472 x := math.Float64frombits(bits) 473 benchmarksRandomBits[i] = FormatFloat(x, 'g', -1, 64) 474 } 475 476 for i := range benchmarksRandomNormal { 477 x := rand.NormFloat64() 478 benchmarksRandomNormal[i] = FormatFloat(x, 'g', -1, 64) 479 } 480 } 481 482 func testAtof(t *testing.T, opt bool) { 483 initAtof() 484 oldopt := SetOptimize(opt) 485 for i := 0; i < len(atoftests); i++ { 486 test := &atoftests[i] 487 out, err := ParseFloat(test.in, 64) 488 outs := FormatFloat(out, 'g', -1, 64) 489 if outs != test.out || !reflect.DeepEqual(err, test.err) { 490 t.Errorf("ParseFloat(%v, 64) = %v, %v want %v, %v", 491 test.in, out, err, test.out, test.err) 492 } 493 494 if float64(float32(out)) == out { 495 out, err := ParseFloat(test.in, 32) 496 out32 := float32(out) 497 if float64(out32) != out { 498 t.Errorf("ParseFloat(%v, 32) = %v, not a float32 (closest is %v)", test.in, out, float64(out32)) 499 continue 500 } 501 outs := FormatFloat(float64(out32), 'g', -1, 32) 502 if outs != test.out || !reflect.DeepEqual(err, test.err) { 503 t.Errorf("ParseFloat(%v, 32) = %v, %v want %v, %v # %v", 504 test.in, out32, err, test.out, test.err, out) 505 } 506 } 507 } 508 for _, test := range atof32tests { 509 out, err := ParseFloat(test.in, 32) 510 out32 := float32(out) 511 if float64(out32) != out { 512 t.Errorf("ParseFloat(%v, 32) = %v, not a float32 (closest is %v)", test.in, out, float64(out32)) 513 continue 514 } 515 outs := FormatFloat(float64(out32), 'g', -1, 32) 516 if outs != test.out || !reflect.DeepEqual(err, test.err) { 517 t.Errorf("ParseFloat(%v, 32) = %v, %v want %v, %v # %v", 518 test.in, out32, err, test.out, test.err, out) 519 } 520 } 521 SetOptimize(oldopt) 522 } 523 524 func TestAtof(t *testing.T) { testAtof(t, true) } 525 526 func TestAtofSlow(t *testing.T) { testAtof(t, false) } 527 528 func TestAtofRandom(t *testing.T) { 529 initAtof() 530 for _, test := range atofRandomTests { 531 x, _ := ParseFloat(test.s, 64) 532 switch { 533 default: 534 t.Errorf("number %s badly parsed as %b (expected %b)", test.s, x, test.x) 535 case x == test.x: 536 case math.IsNaN(test.x) && math.IsNaN(x): 537 } 538 } 539 t.Logf("tested %d random numbers", len(atofRandomTests)) 540 } 541 542 var roundTripCases = []struct { 543 f float64 544 s string 545 }{ 546 // Issue 2917. 547 // This test will break the optimized conversion if the 548 // FPU is using 80-bit registers instead of 64-bit registers, 549 // usually because the operating system initialized the 550 // thread with 80-bit precision and the Go runtime didn't 551 // fix the FP control word. 552 {8865794286000691 << 39, "4.87402195346389e+27"}, 553 {8865794286000692 << 39, "4.8740219534638903e+27"}, 554 } 555 556 func TestRoundTrip(t *testing.T) { 557 for _, tt := range roundTripCases { 558 old := SetOptimize(false) 559 s := FormatFloat(tt.f, 'g', -1, 64) 560 if s != tt.s { 561 t.Errorf("no-opt FormatFloat(%b) = %s, want %s", tt.f, s, tt.s) 562 } 563 f, err := ParseFloat(tt.s, 64) 564 if f != tt.f || err != nil { 565 t.Errorf("no-opt ParseFloat(%s) = %b, %v want %b, nil", tt.s, f, err, tt.f) 566 } 567 SetOptimize(true) 568 s = FormatFloat(tt.f, 'g', -1, 64) 569 if s != tt.s { 570 t.Errorf("opt FormatFloat(%b) = %s, want %s", tt.f, s, tt.s) 571 } 572 f, err = ParseFloat(tt.s, 64) 573 if f != tt.f || err != nil { 574 t.Errorf("opt ParseFloat(%s) = %b, %v want %b, nil", tt.s, f, err, tt.f) 575 } 576 SetOptimize(old) 577 } 578 } 579 580 // TestRoundTrip32 tries a fraction of all finite positive float32 values. 581 func TestRoundTrip32(t *testing.T) { 582 step := uint32(997) 583 if testing.Short() { 584 step = 99991 585 } 586 count := 0 587 for i := uint32(0); i < 0xff<<23; i += step { 588 f := math.Float32frombits(i) 589 if i&1 == 1 { 590 f = -f // negative 591 } 592 s := FormatFloat(float64(f), 'g', -1, 32) 593 594 parsed, err := ParseFloat(s, 32) 595 parsed32 := float32(parsed) 596 switch { 597 case err != nil: 598 t.Errorf("ParseFloat(%q, 32) gave error %s", s, err) 599 case float64(parsed32) != parsed: 600 t.Errorf("ParseFloat(%q, 32) = %v, not a float32 (nearest is %v)", s, parsed, parsed32) 601 case parsed32 != f: 602 t.Errorf("ParseFloat(%q, 32) = %b (expected %b)", s, parsed32, f) 603 } 604 count++ 605 } 606 t.Logf("tested %d float32's", count) 607 } 608 609 func BenchmarkAtof64Decimal(b *testing.B) { 610 for i := 0; i < b.N; i++ { 611 ParseFloat("33909", 64) 612 } 613 } 614 615 func BenchmarkAtof64Float(b *testing.B) { 616 for i := 0; i < b.N; i++ { 617 ParseFloat("339.7784", 64) 618 } 619 } 620 621 func BenchmarkAtof64FloatExp(b *testing.B) { 622 for i := 0; i < b.N; i++ { 623 ParseFloat("-5.09e75", 64) 624 } 625 } 626 627 func BenchmarkAtof64Big(b *testing.B) { 628 for i := 0; i < b.N; i++ { 629 ParseFloat("123456789123456789123456789", 64) 630 } 631 } 632 633 func BenchmarkAtof64RandomBits(b *testing.B) { 634 for i := 0; i < b.N; i++ { 635 ParseFloat(benchmarksRandomBits[i%1024], 64) 636 } 637 } 638 639 func BenchmarkAtof64RandomFloats(b *testing.B) { 640 for i := 0; i < b.N; i++ { 641 ParseFloat(benchmarksRandomNormal[i%1024], 64) 642 } 643 } 644 645 func BenchmarkAtof32Decimal(b *testing.B) { 646 for i := 0; i < b.N; i++ { 647 ParseFloat("33909", 32) 648 } 649 } 650 651 func BenchmarkAtof32Float(b *testing.B) { 652 for i := 0; i < b.N; i++ { 653 ParseFloat("339.778", 32) 654 } 655 } 656 657 func BenchmarkAtof32FloatExp(b *testing.B) { 658 for i := 0; i < b.N; i++ { 659 ParseFloat("12.3456e32", 32) 660 } 661 } 662 663 var float32strings [4096]string 664 665 func BenchmarkAtof32Random(b *testing.B) { 666 n := uint32(997) 667 for i := range float32strings { 668 n = (99991*n + 42) % (0xff << 23) 669 float32strings[i] = FormatFloat(float64(math.Float32frombits(n)), 'g', -1, 32) 670 } 671 b.ResetTimer() 672 for i := 0; i < b.N; i++ { 673 ParseFloat(float32strings[i%4096], 32) 674 } 675 } 676
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