1 /* 2 * Licensed to the Apache Software Foundation (ASF) under one or more 3 * contributor license agreements. See the NOTICE file distributed with 4 * this work for additional information regarding copyright ownership. 5 * The ASF licenses this file to You under the Apache License, Version 2.0 6 * (the "License"); you may not use this file except in compliance with 7 * the License. You may obtain a copy of the License at 8 * 9 * http://www.apache.org/licenses/LICENSE-2.0 10 * 11 * Unless required by applicable law or agreed to in writing, software 12 * distributed under the License is distributed on an "AS IS" BASIS, 13 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 14 * See the License for the specific language governing permissions and 15 * limitations under the License. 16 */ 17 18 #include <stdlib.h> 19 #include <string.h> 20 #include <math.h> 21 #include "JNIHelp.h" 22 #include "JniConstants.h" 23 #include "JniException.h" 24 #include "ScopedUtfChars.h" 25 #include "cbigint.h" 26 27 /* ************************* Defines ************************* */ 28 29 #define LOW_I32_FROM_VAR(u64) LOW_I32_FROM_LONG64(u64) 30 #define LOW_I32_FROM_PTR(u64ptr) LOW_I32_FROM_LONG64_PTR(u64ptr) 31 #define HIGH_I32_FROM_VAR(u64) HIGH_I32_FROM_LONG64(u64) 32 #define HIGH_I32_FROM_PTR(u64ptr) HIGH_I32_FROM_LONG64_PTR(u64ptr) 33 34 #define MAX_DOUBLE_ACCURACY_WIDTH 17 35 36 #define DEFAULT_DOUBLE_WIDTH MAX_DOUBLE_ACCURACY_WIDTH 37 38 #define DOUBLE_INFINITE_LONGBITS (0x7FF0000000000000LL) 39 40 #define DOUBLE_MINIMUM_LONGBITS (0x1) 41 42 #define DOUBLE_MANTISSA_MASK (0x000FFFFFFFFFFFFFLL) 43 #define DOUBLE_EXPONENT_MASK (0x7FF0000000000000LL) 44 #define DOUBLE_NORMAL_MASK (0x0010000000000000LL) 45 46 #define allocateU64(x, n) if (!((x) = reinterpret_cast<uint64_t*>(malloc((n) * sizeof(uint64_t))))) goto OutOfMemory; 47 48 /* *********************************************************** */ 49 50 /* ************************ local data ************************ */ 51 static const jdouble double_tens[] = { 52 1.0, 53 1.0e1, 54 1.0e2, 55 1.0e3, 56 1.0e4, 57 1.0e5, 58 1.0e6, 59 1.0e7, 60 1.0e8, 61 1.0e9, 62 1.0e10, 63 1.0e11, 64 1.0e12, 65 1.0e13, 66 1.0e14, 67 1.0e15, 68 1.0e16, 69 1.0e17, 70 1.0e18, 71 1.0e19, 72 1.0e20, 73 1.0e21, 74 1.0e22 75 }; 76 /* *********************************************************** */ 77 78 /* ************** private function declarations ************** */ 79 static jdouble createDouble1 (JNIEnv* env, uint64_t * f, int32_t length, jint e); 80 static jdouble doubleAlgorithm (JNIEnv* env, uint64_t * f, int32_t length, jint e, 81 jdouble z); 82 /* *********************************************************** */ 83 84 #define doubleTenToTheE(e) (*(double_tens + (e))) 85 #define DOUBLE_LOG5_OF_TWO_TO_THE_N 23 86 87 #define sizeOfTenToTheE(e) (((e) / 19) + 1) 88 89 static jdouble createDouble(JNIEnv* env, const char* s, jint e) { 90 /* assumes s is a null terminated string with at least one 91 * character in it */ 92 uint64_t def[DEFAULT_DOUBLE_WIDTH]; 93 uint64_t defBackup[DEFAULT_DOUBLE_WIDTH]; 94 uint64_t* f; 95 uint64_t* fNoOverflow; 96 uint64_t* g; 97 uint64_t* tempBackup; 98 uint32_t overflow; 99 jdouble result; 100 int32_t index = 1; 101 int unprocessedDigits = 0; 102 103 f = def; 104 fNoOverflow = defBackup; 105 *f = 0; 106 tempBackup = g = 0; 107 do 108 { 109 if (*s >= '0' && *s <= '9') 110 { 111 /* Make a back up of f before appending, so that we can 112 * back out of it if there is no more room, i.e. index > 113 * MAX_DOUBLE_ACCURACY_WIDTH. 114 */ 115 memcpy (fNoOverflow, f, sizeof (uint64_t) * index); 116 overflow = 117 simpleAppendDecimalDigitHighPrecision (f, index, *s - '0'); 118 if (overflow) 119 { 120 f[index++] = overflow; 121 /* There is an overflow, but there is no more room 122 * to store the result. We really only need the top 52 123 * bits anyway, so we must back out of the overflow, 124 * and ignore the rest of the string. 125 */ 126 if (index >= MAX_DOUBLE_ACCURACY_WIDTH) 127 { 128 index--; 129 memcpy (f, fNoOverflow, sizeof (uint64_t) * index); 130 break; 131 } 132 if (tempBackup) 133 { 134 fNoOverflow = tempBackup; 135 } 136 } 137 } 138 else 139 index = -1; 140 } 141 while (index > 0 && *(++s) != '\0'); 142 143 /* We've broken out of the parse loop either because we've reached 144 * the end of the string or we've overflowed the maximum accuracy 145 * limit of a double. If we still have unprocessed digits in the 146 * given string, then there are three possible results: 147 * 1. (unprocessed digits + e) == 0, in which case we simply 148 * convert the existing bits that are already parsed 149 * 2. (unprocessed digits + e) < 0, in which case we simply 150 * convert the existing bits that are already parsed along 151 * with the given e 152 * 3. (unprocessed digits + e) > 0 indicates that the value is 153 * simply too big to be stored as a double, so return Infinity 154 */ 155 if ((unprocessedDigits = strlen (s)) > 0) 156 { 157 e += unprocessedDigits; 158 if (index > -1) 159 { 160 if (e == 0) 161 result = toDoubleHighPrecision (f, index); 162 else if (e < 0) 163 result = createDouble1 (env, f, index, e); 164 else 165 { 166 DOUBLE_TO_LONGBITS (result) = DOUBLE_INFINITE_LONGBITS; 167 } 168 } 169 else 170 { 171 LOW_I32_FROM_VAR (result) = -1; 172 HIGH_I32_FROM_VAR (result) = -1; 173 } 174 } 175 else 176 { 177 if (index > -1) 178 { 179 if (e == 0) 180 result = toDoubleHighPrecision (f, index); 181 else 182 result = createDouble1 (env, f, index, e); 183 } 184 else 185 { 186 LOW_I32_FROM_VAR (result) = -1; 187 HIGH_I32_FROM_VAR (result) = -1; 188 } 189 } 190 191 return result; 192 } 193 194 static jdouble createDouble1(JNIEnv* env, uint64_t* f, int32_t length, jint e) { 195 int32_t numBits; 196 jdouble result; 197 198 static const jint APPROX_MIN_MAGNITUDE = -309; 199 static const jint APPROX_MAX_MAGNITUDE = 309; 200 201 numBits = highestSetBitHighPrecision (f, length) + 1; 202 numBits -= lowestSetBitHighPrecision (f, length); 203 if (numBits < 54 && e >= 0 && e < DOUBLE_LOG5_OF_TWO_TO_THE_N) 204 { 205 return toDoubleHighPrecision (f, length) * doubleTenToTheE (e); 206 } 207 else if (numBits < 54 && e < 0 && (-e) < DOUBLE_LOG5_OF_TWO_TO_THE_N) 208 { 209 return toDoubleHighPrecision (f, length) / doubleTenToTheE (-e); 210 } 211 else if (e >= 0 && e < APPROX_MAX_MAGNITUDE) 212 { 213 result = toDoubleHighPrecision (f, length) * pow (10.0, e); 214 } 215 else if (e >= APPROX_MAX_MAGNITUDE) 216 { 217 /* Convert the partial result to make sure that the 218 * non-exponential part is not zero. This check fixes the case 219 * where the user enters 0.0e309! */ 220 result = toDoubleHighPrecision (f, length); 221 /* Don't go straight to zero as the fact that x*0 = 0 independent of x might 222 cause the algorithm to produce an incorrect result. Instead try the min value 223 first and let it fall to zero if need be. */ 224 225 if (result == 0.0) 226 { 227 DOUBLE_TO_LONGBITS (result) = DOUBLE_MINIMUM_LONGBITS; 228 } 229 else 230 { 231 DOUBLE_TO_LONGBITS (result) = DOUBLE_INFINITE_LONGBITS; 232 return result; 233 } 234 } 235 else if (e > APPROX_MIN_MAGNITUDE) 236 { 237 result = toDoubleHighPrecision (f, length) / pow (10.0, -e); 238 } 239 240 if (e <= APPROX_MIN_MAGNITUDE) 241 { 242 243 result = toDoubleHighPrecision (f, length) * pow (10.0, e + 52); 244 result = result * pow (10.0, -52); 245 246 } 247 248 /* Don't go straight to zero as the fact that x*0 = 0 independent of x might 249 cause the algorithm to produce an incorrect result. Instead try the min value 250 first and let it fall to zero if need be. */ 251 252 if (result == 0.0) 253 DOUBLE_TO_LONGBITS (result) = DOUBLE_MINIMUM_LONGBITS; 254 255 return doubleAlgorithm (env, f, length, e, result); 256 } 257 258 /* The algorithm for the function doubleAlgorithm() below can be found 259 * in: 260 * 261 * "How to Read Floating-Point Numbers Accurately", William D. 262 * Clinger, Proceedings of the ACM SIGPLAN '90 Conference on 263 * Programming Language Design and Implementation, June 20-22, 264 * 1990, pp. 92-101. 265 */ 266 static jdouble doubleAlgorithm(JNIEnv* env, uint64_t* f, int32_t length, jint e, jdouble z) { 267 uint64_t m; 268 int32_t k, comparison, comparison2; 269 uint64_t* x; 270 uint64_t* y; 271 uint64_t* D; 272 uint64_t* D2; 273 int32_t xLength, yLength, DLength, D2Length; 274 275 x = y = D = D2 = 0; 276 xLength = yLength = DLength = D2Length = 0; 277 278 do 279 { 280 m = doubleMantissa (z); 281 k = doubleExponent (z); 282 283 if (x && x != f) 284 free(x); 285 286 free(y); 287 free(D); 288 free(D2); 289 290 if (e >= 0 && k >= 0) 291 { 292 xLength = sizeOfTenToTheE (e) + length; 293 allocateU64 (x, xLength); 294 memset (x + length, 0, sizeof (uint64_t) * (xLength - length)); 295 memcpy (x, f, sizeof (uint64_t) * length); 296 timesTenToTheEHighPrecision (x, xLength, e); 297 298 yLength = (k >> 6) + 2; 299 allocateU64 (y, yLength); 300 memset (y + 1, 0, sizeof (uint64_t) * (yLength - 1)); 301 *y = m; 302 simpleShiftLeftHighPrecision (y, yLength, k); 303 } 304 else if (e >= 0) 305 { 306 xLength = sizeOfTenToTheE (e) + length + ((-k) >> 6) + 1; 307 allocateU64 (x, xLength); 308 memset (x + length, 0, sizeof (uint64_t) * (xLength - length)); 309 memcpy (x, f, sizeof (uint64_t) * length); 310 timesTenToTheEHighPrecision (x, xLength, e); 311 simpleShiftLeftHighPrecision (x, xLength, -k); 312 313 yLength = 1; 314 allocateU64 (y, 1); 315 *y = m; 316 } 317 else if (k >= 0) 318 { 319 xLength = length; 320 x = f; 321 322 yLength = sizeOfTenToTheE (-e) + 2 + (k >> 6); 323 allocateU64 (y, yLength); 324 memset (y + 1, 0, sizeof (uint64_t) * (yLength - 1)); 325 *y = m; 326 timesTenToTheEHighPrecision (y, yLength, -e); 327 simpleShiftLeftHighPrecision (y, yLength, k); 328 } 329 else 330 { 331 xLength = length + ((-k) >> 6) + 1; 332 allocateU64 (x, xLength); 333 memset (x + length, 0, sizeof (uint64_t) * (xLength - length)); 334 memcpy (x, f, sizeof (uint64_t) * length); 335 simpleShiftLeftHighPrecision (x, xLength, -k); 336 337 yLength = sizeOfTenToTheE (-e) + 1; 338 allocateU64 (y, yLength); 339 memset (y + 1, 0, sizeof (uint64_t) * (yLength - 1)); 340 *y = m; 341 timesTenToTheEHighPrecision (y, yLength, -e); 342 } 343 344 comparison = compareHighPrecision (x, xLength, y, yLength); 345 if (comparison > 0) 346 { /* x > y */ 347 DLength = xLength; 348 allocateU64 (D, DLength); 349 memcpy (D, x, DLength * sizeof (uint64_t)); 350 subtractHighPrecision (D, DLength, y, yLength); 351 } 352 else if (comparison) 353 { /* y > x */ 354 DLength = yLength; 355 allocateU64 (D, DLength); 356 memcpy (D, y, DLength * sizeof (uint64_t)); 357 subtractHighPrecision (D, DLength, x, xLength); 358 } 359 else 360 { /* y == x */ 361 DLength = 1; 362 allocateU64 (D, 1); 363 *D = 0; 364 } 365 366 D2Length = DLength + 1; 367 allocateU64 (D2, D2Length); 368 m <<= 1; 369 multiplyHighPrecision (D, DLength, &m, 1, D2, D2Length); 370 m >>= 1; 371 372 comparison2 = compareHighPrecision (D2, D2Length, y, yLength); 373 if (comparison2 < 0) 374 { 375 if (comparison < 0 && m == DOUBLE_NORMAL_MASK 376 && DOUBLE_TO_LONGBITS(z) != DOUBLE_NORMAL_MASK) 377 { 378 simpleShiftLeftHighPrecision (D2, D2Length, 1); 379 if (compareHighPrecision (D2, D2Length, y, yLength) > 0) 380 { 381 --DOUBLE_TO_LONGBITS (z); 382 } 383 else 384 { 385 break; 386 } 387 } 388 else 389 { 390 break; 391 } 392 } 393 else if (comparison2 == 0) 394 { 395 if ((LOW_U32_FROM_VAR (m) & 1) == 0) 396 { 397 if (comparison < 0 && m == DOUBLE_NORMAL_MASK) 398 { 399 --DOUBLE_TO_LONGBITS (z); 400 } 401 else 402 { 403 break; 404 } 405 } 406 else if (comparison < 0) 407 { 408 --DOUBLE_TO_LONGBITS (z); 409 break; 410 } 411 else 412 { 413 ++DOUBLE_TO_LONGBITS (z); 414 break; 415 } 416 } 417 else if (comparison < 0) 418 { 419 --DOUBLE_TO_LONGBITS (z); 420 } 421 else 422 { 423 if (DOUBLE_TO_LONGBITS (z) == DOUBLE_INFINITE_LONGBITS) 424 break; 425 ++DOUBLE_TO_LONGBITS (z); 426 } 427 } 428 while (1); 429 430 if (x && x != f) 431 free(x); 432 free(y); 433 free(D); 434 free(D2); 435 return z; 436 437 OutOfMemory: 438 if (x && x != f) 439 free(x); 440 free(y); 441 free(D); 442 free(D2); 443 jniThrowOutOfMemoryError(env, NULL); 444 return z; 445 } 446 447 448 449 #define MAX_FLOAT_ACCURACY_WIDTH 8 450 451 #define DEFAULT_FLOAT_WIDTH MAX_FLOAT_ACCURACY_WIDTH 452 453 static jfloat createFloat1(JNIEnv* env, uint64_t* f, int32_t length, jint e); 454 static jfloat floatAlgorithm(JNIEnv* env, uint64_t* f, int32_t length, jint e, jfloat z); 455 456 static const uint32_t float_tens[] = { 457 0x3f800000, 458 0x41200000, 459 0x42c80000, 460 0x447a0000, 461 0x461c4000, 462 0x47c35000, 463 0x49742400, 464 0x4b189680, 465 0x4cbebc20, 466 0x4e6e6b28, 467 0x501502f9 /* 10 ^ 10 in float */ 468 }; 469 470 #define floatTenToTheE(e) (*reinterpret_cast<const jfloat*>(float_tens + (e))) 471 #define FLOAT_LOG5_OF_TWO_TO_THE_N 11 472 473 #define FLOAT_INFINITE_INTBITS (0x7F800000) 474 #define FLOAT_MINIMUM_INTBITS (1) 475 476 #define FLOAT_MANTISSA_MASK (0x007FFFFF) 477 #define FLOAT_EXPONENT_MASK (0x7F800000) 478 #define FLOAT_NORMAL_MASK (0x00800000) 479 480 static jfloat createFloat(JNIEnv* env, const char* s, jint e) { 481 /* assumes s is a null terminated string with at least one 482 * character in it */ 483 uint64_t def[DEFAULT_FLOAT_WIDTH]; 484 uint64_t defBackup[DEFAULT_FLOAT_WIDTH]; 485 uint64_t* f; 486 uint64_t* fNoOverflow; 487 uint64_t* g; 488 uint64_t* tempBackup; 489 uint32_t overflow; 490 jfloat result; 491 int32_t index = 1; 492 int unprocessedDigits = 0; 493 494 f = def; 495 fNoOverflow = defBackup; 496 *f = 0; 497 tempBackup = g = 0; 498 do 499 { 500 if (*s >= '0' && *s <= '9') 501 { 502 /* Make a back up of f before appending, so that we can 503 * back out of it if there is no more room, i.e. index > 504 * MAX_FLOAT_ACCURACY_WIDTH. 505 */ 506 memcpy (fNoOverflow, f, sizeof (uint64_t) * index); 507 overflow = 508 simpleAppendDecimalDigitHighPrecision (f, index, *s - '0'); 509 if (overflow) 510 { 511 512 f[index++] = overflow; 513 /* There is an overflow, but there is no more room 514 * to store the result. We really only need the top 52 515 * bits anyway, so we must back out of the overflow, 516 * and ignore the rest of the string. 517 */ 518 if (index >= MAX_FLOAT_ACCURACY_WIDTH) 519 { 520 index--; 521 memcpy (f, fNoOverflow, sizeof (uint64_t) * index); 522 break; 523 } 524 if (tempBackup) 525 { 526 fNoOverflow = tempBackup; 527 } 528 } 529 } 530 else 531 index = -1; 532 } 533 while (index > 0 && *(++s) != '\0'); 534 535 /* We've broken out of the parse loop either because we've reached 536 * the end of the string or we've overflowed the maximum accuracy 537 * limit of a double. If we still have unprocessed digits in the 538 * given string, then there are three possible results: 539 * 1. (unprocessed digits + e) == 0, in which case we simply 540 * convert the existing bits that are already parsed 541 * 2. (unprocessed digits + e) < 0, in which case we simply 542 * convert the existing bits that are already parsed along 543 * with the given e 544 * 3. (unprocessed digits + e) > 0 indicates that the value is 545 * simply too big to be stored as a double, so return Infinity 546 */ 547 if ((unprocessedDigits = strlen (s)) > 0) 548 { 549 e += unprocessedDigits; 550 if (index > -1) 551 { 552 if (e <= 0) 553 { 554 result = createFloat1 (env, f, index, e); 555 } 556 else 557 { 558 FLOAT_TO_INTBITS (result) = FLOAT_INFINITE_INTBITS; 559 } 560 } 561 else 562 { 563 result = INTBITS_TO_FLOAT(index); 564 } 565 } 566 else 567 { 568 if (index > -1) 569 { 570 result = createFloat1 (env, f, index, e); 571 } 572 else 573 { 574 result = INTBITS_TO_FLOAT(index); 575 } 576 } 577 578 return result; 579 } 580 581 static jfloat createFloat1 (JNIEnv* env, uint64_t* f, int32_t length, jint e) { 582 int32_t numBits; 583 jdouble dresult; 584 jfloat result; 585 586 numBits = highestSetBitHighPrecision (f, length) + 1; 587 if (numBits < 25 && e >= 0 && e < FLOAT_LOG5_OF_TWO_TO_THE_N) 588 { 589 return ((jfloat) LOW_I32_FROM_PTR (f)) * floatTenToTheE (e); 590 } 591 else if (numBits < 25 && e < 0 && (-e) < FLOAT_LOG5_OF_TWO_TO_THE_N) 592 { 593 return ((jfloat) LOW_I32_FROM_PTR (f)) / floatTenToTheE (-e); 594 } 595 else if (e >= 0 && e < 39) 596 { 597 result = (jfloat) (toDoubleHighPrecision (f, length) * pow (10.0, (double) e)); 598 } 599 else if (e >= 39) 600 { 601 /* Convert the partial result to make sure that the 602 * non-exponential part is not zero. This check fixes the case 603 * where the user enters 0.0e309! */ 604 result = (jfloat) toDoubleHighPrecision (f, length); 605 606 if (result == 0.0) 607 608 FLOAT_TO_INTBITS (result) = FLOAT_MINIMUM_INTBITS; 609 else 610 FLOAT_TO_INTBITS (result) = FLOAT_INFINITE_INTBITS; 611 } 612 else if (e > -309) 613 { 614 int dexp; 615 uint32_t fmant, fovfl; 616 uint64_t dmant; 617 dresult = toDoubleHighPrecision (f, length) / pow (10.0, (double) -e); 618 if (IS_DENORMAL_DBL (dresult)) 619 { 620 FLOAT_TO_INTBITS (result) = 0; 621 return result; 622 } 623 dexp = doubleExponent (dresult) + 51; 624 dmant = doubleMantissa (dresult); 625 /* Is it too small to be represented by a single-precision 626 * float? */ 627 if (dexp <= -155) 628 { 629 FLOAT_TO_INTBITS (result) = 0; 630 return result; 631 } 632 /* Is it a denormalized single-precision float? */ 633 if ((dexp <= -127) && (dexp > -155)) 634 { 635 /* Only interested in 24 msb bits of the 53-bit double mantissa */ 636 fmant = (uint32_t) (dmant >> 29); 637 fovfl = ((uint32_t) (dmant & 0x1FFFFFFF)) << 3; 638 while ((dexp < -127) && ((fmant | fovfl) != 0)) 639 { 640 if ((fmant & 1) != 0) 641 { 642 fovfl |= 0x80000000; 643 } 644 fovfl >>= 1; 645 fmant >>= 1; 646 dexp++; 647 } 648 if ((fovfl & 0x80000000) != 0) 649 { 650 if ((fovfl & 0x7FFFFFFC) != 0) 651 { 652 fmant++; 653 } 654 else if ((fmant & 1) != 0) 655 { 656 fmant++; 657 } 658 } 659 else if ((fovfl & 0x40000000) != 0) 660 { 661 if ((fovfl & 0x3FFFFFFC) != 0) 662 { 663 fmant++; 664 } 665 } 666 FLOAT_TO_INTBITS (result) = fmant; 667 } 668 else 669 { 670 result = (jfloat) dresult; 671 } 672 } 673 674 /* Don't go straight to zero as the fact that x*0 = 0 independent 675 * of x might cause the algorithm to produce an incorrect result. 676 * Instead try the min value first and let it fall to zero if need 677 * be. 678 */ 679 if (e <= -309 || FLOAT_TO_INTBITS (result) == 0) 680 FLOAT_TO_INTBITS (result) = FLOAT_MINIMUM_INTBITS; 681 682 return floatAlgorithm (env, f, length, e, (jfloat) result); 683 } 684 685 /* The algorithm for the function floatAlgorithm() below can be found 686 * in: 687 * 688 * "How to Read Floating-Point Numbers Accurately", William D. 689 * Clinger, Proceedings of the ACM SIGPLAN '90 Conference on 690 * Programming Language Design and Implementation, June 20-22, 691 * 1990, pp. 92-101. 692 */ 693 static jfloat floatAlgorithm(JNIEnv* env, uint64_t* f, int32_t length, jint e, jfloat z) { 694 uint64_t m; 695 int32_t k, comparison, comparison2; 696 uint64_t* x; 697 uint64_t* y; 698 uint64_t* D; 699 uint64_t* D2; 700 int32_t xLength, yLength, DLength, D2Length; 701 702 x = y = D = D2 = 0; 703 xLength = yLength = DLength = D2Length = 0; 704 705 do 706 { 707 m = floatMantissa (z); 708 k = floatExponent (z); 709 710 if (x && x != f) 711 free(x); 712 713 free(y); 714 free(D); 715 free(D2); 716 717 if (e >= 0 && k >= 0) 718 { 719 xLength = sizeOfTenToTheE (e) + length; 720 allocateU64 (x, xLength); 721 memset (x + length, 0, sizeof (uint64_t) * (xLength - length)); 722 memcpy (x, f, sizeof (uint64_t) * length); 723 timesTenToTheEHighPrecision (x, xLength, e); 724 725 yLength = (k >> 6) + 2; 726 allocateU64 (y, yLength); 727 memset (y + 1, 0, sizeof (uint64_t) * (yLength - 1)); 728 *y = m; 729 simpleShiftLeftHighPrecision (y, yLength, k); 730 } 731 else if (e >= 0) 732 { 733 xLength = sizeOfTenToTheE (e) + length + ((-k) >> 6) + 1; 734 allocateU64 (x, xLength); 735 memset (x + length, 0, sizeof (uint64_t) * (xLength - length)); 736 memcpy (x, f, sizeof (uint64_t) * length); 737 timesTenToTheEHighPrecision (x, xLength, e); 738 simpleShiftLeftHighPrecision (x, xLength, -k); 739 740 yLength = 1; 741 allocateU64 (y, 1); 742 *y = m; 743 } 744 else if (k >= 0) 745 { 746 xLength = length; 747 x = f; 748 749 yLength = sizeOfTenToTheE (-e) + 2 + (k >> 6); 750 allocateU64 (y, yLength); 751 memset (y + 1, 0, sizeof (uint64_t) * (yLength - 1)); 752 *y = m; 753 timesTenToTheEHighPrecision (y, yLength, -e); 754 simpleShiftLeftHighPrecision (y, yLength, k); 755 } 756 else 757 { 758 xLength = length + ((-k) >> 6) + 1; 759 allocateU64 (x, xLength); 760 memset (x + length, 0, sizeof (uint64_t) * (xLength - length)); 761 memcpy (x, f, sizeof (uint64_t) * length); 762 simpleShiftLeftHighPrecision (x, xLength, -k); 763 764 yLength = sizeOfTenToTheE (-e) + 1; 765 allocateU64 (y, yLength); 766 memset (y + 1, 0, sizeof (uint64_t) * (yLength - 1)); 767 *y = m; 768 timesTenToTheEHighPrecision (y, yLength, -e); 769 } 770 771 comparison = compareHighPrecision (x, xLength, y, yLength); 772 if (comparison > 0) 773 { /* x > y */ 774 DLength = xLength; 775 allocateU64 (D, DLength); 776 memcpy (D, x, DLength * sizeof (uint64_t)); 777 subtractHighPrecision (D, DLength, y, yLength); 778 } 779 else if (comparison) 780 { /* y > x */ 781 DLength = yLength; 782 allocateU64 (D, DLength); 783 memcpy (D, y, DLength * sizeof (uint64_t)); 784 subtractHighPrecision (D, DLength, x, xLength); 785 } 786 else 787 { /* y == x */ 788 DLength = 1; 789 allocateU64 (D, 1); 790 *D = 0; 791 } 792 793 D2Length = DLength + 1; 794 allocateU64 (D2, D2Length); 795 m <<= 1; 796 multiplyHighPrecision (D, DLength, &m, 1, D2, D2Length); 797 m >>= 1; 798 799 comparison2 = compareHighPrecision (D2, D2Length, y, yLength); 800 if (comparison2 < 0) 801 { 802 if (comparison < 0 && m == FLOAT_NORMAL_MASK 803 && FLOAT_TO_INTBITS(z) != FLOAT_NORMAL_MASK) 804 { 805 simpleShiftLeftHighPrecision (D2, D2Length, 1); 806 if (compareHighPrecision (D2, D2Length, y, yLength) > 0) 807 { 808 --FLOAT_TO_INTBITS (z); 809 } 810 else 811 { 812 break; 813 } 814 } 815 else 816 { 817 break; 818 } 819 } 820 else if (comparison2 == 0) 821 { 822 if ((m & 1) == 0) 823 { 824 if (comparison < 0 && m == FLOAT_NORMAL_MASK) 825 { 826 --FLOAT_TO_INTBITS (z); 827 } 828 else 829 { 830 break; 831 } 832 } 833 else if (comparison < 0) 834 { 835 --FLOAT_TO_INTBITS (z); 836 break; 837 } 838 else 839 { 840 ++FLOAT_TO_INTBITS (z); 841 break; 842 } 843 } 844 else if (comparison < 0) 845 { 846 --FLOAT_TO_INTBITS (z); 847 } 848 else 849 { 850 if (FLOAT_TO_INTBITS (z) == FLOAT_EXPONENT_MASK) 851 break; 852 ++FLOAT_TO_INTBITS (z); 853 } 854 } 855 while (1); 856 857 if (x && x != f) 858 free(x); 859 free(y); 860 free(D); 861 free(D2); 862 return z; 863 864 OutOfMemory: 865 if (x && x != f) 866 free(x); 867 free(y); 868 free(D); 869 free(D2); 870 jniThrowOutOfMemoryError(env, NULL); 871 return z; 872 } 873 874 static jfloat StringToReal_parseFltImpl(JNIEnv* env, jclass, jstring s, jint e) { 875 ScopedUtfChars str(env, s); 876 if (str.c_str() == NULL) { 877 return 0.0; 878 } 879 return createFloat(env, str.c_str(), e); 880 } 881 882 static jdouble StringToReal_parseDblImpl(JNIEnv* env, jclass, jstring s, jint e) { 883 ScopedUtfChars str(env, s); 884 if (str.c_str() == NULL) { 885 return 0.0; 886 } 887 return createDouble(env, str.c_str(), e); 888 } 889 890 static JNINativeMethod gMethods[] = { 891 NATIVE_METHOD(StringToReal, parseFltImpl, "(Ljava/lang/String;I)F"), 892 NATIVE_METHOD(StringToReal, parseDblImpl, "(Ljava/lang/String;I)D"), 893 }; 894 void register_java_lang_StringToReal(JNIEnv* env) { 895 jniRegisterNativeMethods(env, "java/lang/StringToReal", gMethods, NELEM(gMethods)); 896 } 897
