Changeset 388 for python/vendor/current/Objects/floatobject.c
- Timestamp:
- Mar 19, 2014, 11:11:30 AM (11 years ago)
- File:
-
- 1 edited
Legend:
- Unmodified
- Added
- Removed
-
python/vendor/current/Objects/floatobject.c
r2 r388 16 16 #define MIN(x, y) ((x) < (y) ? (x) : (y)) 17 17 18 #ifdef HAVE_IEEEFP_H19 #include <ieeefp.h>20 #endif21 22 18 #ifdef _OSF_SOURCE 23 19 /* OSF1 5.1 doesn't make this available with XOPEN_SOURCE_EXTENDED defined */ … … 26 22 27 23 /* Special free list -- see comments for same code in intobject.c. */ 28 #define BLOCK_SIZE 1000/* 1K less typical malloc overhead */29 #define BHEAD_SIZE 8/* Enough for a 64-bit pointer */30 #define N_FLOATOBJECTS 24 #define BLOCK_SIZE 1000 /* 1K less typical malloc overhead */ 25 #define BHEAD_SIZE 8 /* Enough for a 64-bit pointer */ 26 #define N_FLOATOBJECTS ((BLOCK_SIZE - BHEAD_SIZE) / sizeof(PyFloatObject)) 31 27 32 28 struct _floatblock { 33 34 29 struct _floatblock *next; 30 PyFloatObject objects[N_FLOATOBJECTS]; 35 31 }; 36 32 … … 43 39 fill_free_list(void) 44 40 { 45 46 47 48 49 50 51 52 53 54 55 56 57 41 PyFloatObject *p, *q; 42 /* XXX Float blocks escape the object heap. Use PyObject_MALLOC ??? */ 43 p = (PyFloatObject *) PyMem_MALLOC(sizeof(PyFloatBlock)); 44 if (p == NULL) 45 return (PyFloatObject *) PyErr_NoMemory(); 46 ((PyFloatBlock *)p)->next = block_list; 47 block_list = (PyFloatBlock *)p; 48 p = &((PyFloatBlock *)p)->objects[0]; 49 q = p + N_FLOATOBJECTS; 50 while (--q > p) 51 Py_TYPE(q) = (struct _typeobject *)(q-1); 52 Py_TYPE(q) = NULL; 53 return p + N_FLOATOBJECTS - 1; 58 54 } 59 55 … … 61 57 PyFloat_GetMax(void) 62 58 { 63 59 return DBL_MAX; 64 60 } 65 61 … … 67 63 PyFloat_GetMin(void) 68 64 { 69 65 return DBL_MIN; 70 66 } 71 67 … … 73 69 74 70 PyDoc_STRVAR(floatinfo__doc__, 75 "sys.float info\n\71 "sys.float_info\n\ 76 72 \n\ 77 73 A structseq holding information about the float type. It contains low level\n\ … … 80 76 81 77 static PyStructSequence_Field floatinfo_fields[] = { 82 {"max","DBL_MAX -- maximum representable finite float"},83 {"max_exp","DBL_MAX_EXP -- maximum int e such that radix**(e-1) "84 85 {"max_10_exp","DBL_MAX_10_EXP -- maximum int e such that 10**e "86 87 {"min","DBL_MIN -- Minimum positive normalizer float"},88 {"min_exp","DBL_MIN_EXP -- minimum int e such that radix**(e-1) "89 90 {"min_10_exp","DBL_MIN_10_EXP -- minimum int e such that 10**e is "91 92 {"dig","DBL_DIG -- digits"},93 {"mant_dig","DBL_MANT_DIG -- mantissa digits"},94 {"epsilon","DBL_EPSILON -- Difference between 1 and the next "95 96 {"radix","FLT_RADIX -- radix of exponent"},97 {"rounds","FLT_ROUNDS -- addition rounds"},98 78 {"max", "DBL_MAX -- maximum representable finite float"}, 79 {"max_exp", "DBL_MAX_EXP -- maximum int e such that radix**(e-1) " 80 "is representable"}, 81 {"max_10_exp", "DBL_MAX_10_EXP -- maximum int e such that 10**e " 82 "is representable"}, 83 {"min", "DBL_MIN -- Minimum positive normalizer float"}, 84 {"min_exp", "DBL_MIN_EXP -- minimum int e such that radix**(e-1) " 85 "is a normalized float"}, 86 {"min_10_exp", "DBL_MIN_10_EXP -- minimum int e such that 10**e is " 87 "a normalized"}, 88 {"dig", "DBL_DIG -- digits"}, 89 {"mant_dig", "DBL_MANT_DIG -- mantissa digits"}, 90 {"epsilon", "DBL_EPSILON -- Difference between 1 and the next " 91 "representable float"}, 92 {"radix", "FLT_RADIX -- radix of exponent"}, 93 {"rounds", "FLT_ROUNDS -- addition rounds"}, 94 {0} 99 95 }; 100 96 101 97 static PyStructSequence_Desc floatinfo_desc = { 102 "sys.floatinfo",/* name */103 floatinfo__doc__,/* doc */104 floatinfo_fields,/* fields */105 98 "sys.float_info", /* name */ 99 floatinfo__doc__, /* doc */ 100 floatinfo_fields, /* fields */ 101 11 106 102 }; 107 103 … … 109 105 PyFloat_GetInfo(void) 110 106 { 111 112 113 114 115 116 117 107 PyObject* floatinfo; 108 int pos = 0; 109 110 floatinfo = PyStructSequence_New(&FloatInfoType); 111 if (floatinfo == NULL) { 112 return NULL; 113 } 118 114 119 115 #define SetIntFlag(flag) \ 120 116 PyStructSequence_SET_ITEM(floatinfo, pos++, PyInt_FromLong(flag)) 121 117 #define SetDblFlag(flag) \ 122 123 124 125 126 127 128 129 130 131 132 133 134 118 PyStructSequence_SET_ITEM(floatinfo, pos++, PyFloat_FromDouble(flag)) 119 120 SetDblFlag(DBL_MAX); 121 SetIntFlag(DBL_MAX_EXP); 122 SetIntFlag(DBL_MAX_10_EXP); 123 SetDblFlag(DBL_MIN); 124 SetIntFlag(DBL_MIN_EXP); 125 SetIntFlag(DBL_MIN_10_EXP); 126 SetIntFlag(DBL_DIG); 127 SetIntFlag(DBL_MANT_DIG); 128 SetDblFlag(DBL_EPSILON); 129 SetIntFlag(FLT_RADIX); 130 SetIntFlag(FLT_ROUNDS); 135 131 #undef SetIntFlag 136 132 #undef SetDblFlag 137 138 139 140 141 142 133 134 if (PyErr_Occurred()) { 135 Py_CLEAR(floatinfo); 136 return NULL; 137 } 138 return floatinfo; 143 139 } 144 140 … … 146 142 PyFloat_FromDouble(double fval) 147 143 { 148 149 150 151 152 153 154 155 156 157 158 144 register PyFloatObject *op; 145 if (free_list == NULL) { 146 if ((free_list = fill_free_list()) == NULL) 147 return NULL; 148 } 149 /* Inline PyObject_New */ 150 op = free_list; 151 free_list = (PyFloatObject *)Py_TYPE(op); 152 PyObject_INIT(op, &PyFloat_Type); 153 op->ob_fval = fval; 154 return (PyObject *) op; 159 155 } 160 156 … … 178 174 PyFloat_FromString(PyObject *v, char **pend) 179 175 { 180 const char *s, *last, *end, *sp;181 182 176 const char *s, *last, *end; 177 double x; 178 char buffer[256]; /* for errors */ 183 179 #ifdef Py_USING_UNICODE 184 char s_buffer[256]; /* for objects convertible to a char buffer */ 180 char *s_buffer = NULL; 185 181 #endif 186 Py_ssize_t len; 187 188 if (pend) 189 *pend = NULL; 190 if (PyString_Check(v)) { 191 s = PyString_AS_STRING(v); 192 len = PyString_GET_SIZE(v); 193 } 182 Py_ssize_t len; 183 PyObject *result = NULL; 184 185 if (pend) 186 *pend = NULL; 187 if (PyString_Check(v)) { 188 s = PyString_AS_STRING(v); 189 len = PyString_GET_SIZE(v); 190 } 194 191 #ifdef Py_USING_UNICODE 195 else if (PyUnicode_Check(v)) { 196 if (PyUnicode_GET_SIZE(v) >= (Py_ssize_t)sizeof(s_buffer)) { 197 PyErr_SetString(PyExc_ValueError, 198 "Unicode float() literal too long to convert"); 199 return NULL; 200 } 201 if (PyUnicode_EncodeDecimal(PyUnicode_AS_UNICODE(v), 202 PyUnicode_GET_SIZE(v), 203 s_buffer, 204 NULL)) 205 return NULL; 206 s = s_buffer; 207 len = strlen(s); 208 } 192 else if (PyUnicode_Check(v)) { 193 s_buffer = (char *)PyMem_MALLOC(PyUnicode_GET_SIZE(v)+1); 194 if (s_buffer == NULL) 195 return PyErr_NoMemory(); 196 if (PyUnicode_EncodeDecimal(PyUnicode_AS_UNICODE(v), 197 PyUnicode_GET_SIZE(v), 198 s_buffer, 199 NULL)) 200 goto error; 201 s = s_buffer; 202 len = strlen(s); 203 } 209 204 #endif 210 else if (PyObject_AsCharBuffer(v, &s, &len)) { 211 PyErr_SetString(PyExc_TypeError, 212 "float() argument must be a string or a number"); 213 return NULL; 214 } 215 216 last = s + len; 217 while (*s && isspace(Py_CHARMASK(*s))) 218 s++; 219 if (*s == '\0') { 220 PyErr_SetString(PyExc_ValueError, "empty string for float()"); 221 return NULL; 222 } 223 sp = s; 224 /* We don't care about overflow or underflow. If the platform supports 225 * them, infinities and signed zeroes (on underflow) are fine. 226 * However, strtod can return 0 for denormalized numbers, where atof 227 * does not. So (alas!) we special-case a zero result. Note that 228 * whether strtod sets errno on underflow is not defined, so we can't 229 * key off errno. 230 */ 231 PyFPE_START_PROTECT("strtod", return NULL) 232 x = PyOS_ascii_strtod(s, (char **)&end); 233 PyFPE_END_PROTECT(x) 234 errno = 0; 235 /* Believe it or not, Solaris 2.6 can move end *beyond* the null 236 byte at the end of the string, when the input is inf(inity). */ 237 if (end > last) 238 end = last; 239 /* Check for inf and nan. This is done late because it rarely happens. */ 240 if (end == s) { 241 char *p = (char*)sp; 242 int sign = 1; 243 244 if (*p == '-') { 245 sign = -1; 246 p++; 247 } 248 if (*p == '+') { 249 p++; 250 } 251 if (PyOS_strnicmp(p, "inf", 4) == 0) { 252 Py_RETURN_INF(sign); 253 } 254 if (PyOS_strnicmp(p, "infinity", 9) == 0) { 255 Py_RETURN_INF(sign); 256 } 257 #ifdef Py_NAN 258 if(PyOS_strnicmp(p, "nan", 4) == 0) { 259 Py_RETURN_NAN; 260 } 205 else if (PyObject_AsCharBuffer(v, &s, &len)) { 206 PyErr_SetString(PyExc_TypeError, 207 "float() argument must be a string or a number"); 208 return NULL; 209 } 210 last = s + len; 211 212 while (Py_ISSPACE(*s)) 213 s++; 214 /* We don't care about overflow or underflow. If the platform 215 * supports them, infinities and signed zeroes (on underflow) are 216 * fine. */ 217 x = PyOS_string_to_double(s, (char **)&end, NULL); 218 if (x == -1.0 && PyErr_Occurred()) 219 goto error; 220 while (Py_ISSPACE(*end)) 221 end++; 222 if (end == last) 223 result = PyFloat_FromDouble(x); 224 else { 225 PyOS_snprintf(buffer, sizeof(buffer), 226 "invalid literal for float(): %.200s", s); 227 PyErr_SetString(PyExc_ValueError, buffer); 228 result = NULL; 229 } 230 231 error: 232 #ifdef Py_USING_UNICODE 233 if (s_buffer) 234 PyMem_FREE(s_buffer); 261 235 #endif 262 PyOS_snprintf(buffer, sizeof(buffer), 263 "invalid literal for float(): %.200s", s); 264 PyErr_SetString(PyExc_ValueError, buffer); 265 return NULL; 266 } 267 /* Since end != s, the platform made *some* kind of sense out 268 of the input. Trust it. */ 269 while (*end && isspace(Py_CHARMASK(*end))) 270 end++; 271 if (*end != '\0') { 272 PyOS_snprintf(buffer, sizeof(buffer), 273 "invalid literal for float(): %.200s", s); 274 PyErr_SetString(PyExc_ValueError, buffer); 275 return NULL; 276 } 277 else if (end != last) { 278 PyErr_SetString(PyExc_ValueError, 279 "null byte in argument for float()"); 280 return NULL; 281 } 282 if (x == 0.0) { 283 /* See above -- may have been strtod being anal 284 about denorms. */ 285 PyFPE_START_PROTECT("atof", return NULL) 286 x = PyOS_ascii_atof(s); 287 PyFPE_END_PROTECT(x) 288 errno = 0; /* whether atof ever set errno is undefined */ 289 } 290 return PyFloat_FromDouble(x); 236 return result; 291 237 } 292 238 … … 294 240 float_dealloc(PyFloatObject *op) 295 241 { 296 297 298 299 300 301 242 if (PyFloat_CheckExact(op)) { 243 Py_TYPE(op) = (struct _typeobject *)free_list; 244 free_list = op; 245 } 246 else 247 Py_TYPE(op)->tp_free((PyObject *)op); 302 248 } 303 249 … … 305 251 PyFloat_AsDouble(PyObject *op) 306 252 { 307 308 309 310 311 312 313 314 315 316 317 318 319 320 321 322 323 324 325 326 327 328 329 330 331 332 333 334 335 336 253 PyNumberMethods *nb; 254 PyFloatObject *fo; 255 double val; 256 257 if (op && PyFloat_Check(op)) 258 return PyFloat_AS_DOUBLE((PyFloatObject*) op); 259 260 if (op == NULL) { 261 PyErr_BadArgument(); 262 return -1; 263 } 264 265 if ((nb = Py_TYPE(op)->tp_as_number) == NULL || nb->nb_float == NULL) { 266 PyErr_SetString(PyExc_TypeError, "a float is required"); 267 return -1; 268 } 269 270 fo = (PyFloatObject*) (*nb->nb_float) (op); 271 if (fo == NULL) 272 return -1; 273 if (!PyFloat_Check(fo)) { 274 PyErr_SetString(PyExc_TypeError, 275 "nb_float should return float object"); 276 return -1; 277 } 278 279 val = PyFloat_AS_DOUBLE(fo); 280 Py_DECREF(fo); 281 282 return val; 337 283 } 338 284 339 285 /* Methods */ 340 341 static void342 format_float(char *buf, size_t buflen, PyFloatObject *v, int precision)343 {344 register char *cp;345 char format[32];346 int i;347 348 /* Subroutine for float_repr and float_print.349 We want float numbers to be recognizable as such,350 i.e., they should contain a decimal point or an exponent.351 However, %g may print the number as an integer;352 in such cases, we append ".0" to the string. */353 354 assert(PyFloat_Check(v));355 PyOS_snprintf(format, 32, "%%.%ig", precision);356 PyOS_ascii_formatd(buf, buflen, format, v->ob_fval);357 cp = buf;358 if (*cp == '-')359 cp++;360 for (; *cp != '\0'; cp++) {361 /* Any non-digit means it's not an integer;362 this takes care of NAN and INF as well. */363 if (!isdigit(Py_CHARMASK(*cp)))364 break;365 }366 if (*cp == '\0') {367 *cp++ = '.';368 *cp++ = '0';369 *cp++ = '\0';370 return;371 }372 /* Checking the next three chars should be more than enough to373 * detect inf or nan, even on Windows. We check for inf or nan374 * at last because they are rare cases.375 */376 for (i=0; *cp != '\0' && i<3; cp++, i++) {377 if (isdigit(Py_CHARMASK(*cp)) || *cp == '.')378 continue;379 /* found something that is neither a digit nor point380 * it might be a NaN or INF381 */382 #ifdef Py_NAN383 if (Py_IS_NAN(v->ob_fval)) {384 strcpy(buf, "nan");385 }386 else387 #endif388 if (Py_IS_INFINITY(v->ob_fval)) {389 cp = buf;390 if (*cp == '-')391 cp++;392 strcpy(cp, "inf");393 }394 break;395 }396 397 }398 399 /* XXX PyFloat_AsStringEx should not be a public API function (for one400 XXX thing, its signature passes a buffer without a length; for another,401 XXX it isn't useful outside this file).402 */403 void404 PyFloat_AsStringEx(char *buf, PyFloatObject *v, int precision)405 {406 format_float(buf, 100, v, precision);407 }408 286 409 287 /* Macro and helper that convert PyObject obj to a C double and store … … 414 292 stored in obj, and returned from the function invoking this macro. 415 293 */ 416 #define CONVERT_TO_DOUBLE(obj, dbl) 417 if (PyFloat_Check(obj))\418 dbl = PyFloat_AS_DOUBLE(obj);\419 else if (convert_to_double(&(obj), &(dbl)) < 0)\420 294 #define CONVERT_TO_DOUBLE(obj, dbl) \ 295 if (PyFloat_Check(obj)) \ 296 dbl = PyFloat_AS_DOUBLE(obj); \ 297 else if (convert_to_double(&(obj), &(dbl)) < 0) \ 298 return obj; 421 299 422 300 static int 423 301 convert_to_double(PyObject **v, double *dbl) 424 302 { 425 register PyObject *obj = *v; 426 427 if (PyInt_Check(obj)) { 428 *dbl = (double)PyInt_AS_LONG(obj); 429 } 430 else if (PyLong_Check(obj)) { 431 *dbl = PyLong_AsDouble(obj); 432 if (*dbl == -1.0 && PyErr_Occurred()) { 433 *v = NULL; 434 return -1; 435 } 436 } 437 else { 438 Py_INCREF(Py_NotImplemented); 439 *v = Py_NotImplemented; 440 return -1; 441 } 442 return 0; 443 } 444 445 /* Precisions used by repr() and str(), respectively. 446 447 The repr() precision (17 significant decimal digits) is the minimal number 448 that is guaranteed to have enough precision so that if the number is read 449 back in the exact same binary value is recreated. This is true for IEEE 450 floating point by design, and also happens to work for all other modern 451 hardware. 452 453 The str() precision is chosen so that in most cases, the rounding noise 454 created by various operations is suppressed, while giving plenty of 455 precision for practical use. 456 457 */ 458 459 #define PREC_REPR 17 460 #define PREC_STR 12 461 462 /* XXX PyFloat_AsString and PyFloat_AsReprString should be deprecated: 303 register PyObject *obj = *v; 304 305 if (PyInt_Check(obj)) { 306 *dbl = (double)PyInt_AS_LONG(obj); 307 } 308 else if (PyLong_Check(obj)) { 309 *dbl = PyLong_AsDouble(obj); 310 if (*dbl == -1.0 && PyErr_Occurred()) { 311 *v = NULL; 312 return -1; 313 } 314 } 315 else { 316 Py_INCREF(Py_NotImplemented); 317 *v = Py_NotImplemented; 318 return -1; 319 } 320 return 0; 321 } 322 323 /* XXX PyFloat_AsString and PyFloat_AsReprString are deprecated: 463 324 XXX they pass a char buffer without passing a length. 464 325 */ … … 466 327 PyFloat_AsString(char *buf, PyFloatObject *v) 467 328 { 468 format_float(buf, 100, v, PREC_STR); 329 char *tmp = PyOS_double_to_string(v->ob_fval, 'g', 330 PyFloat_STR_PRECISION, 331 Py_DTSF_ADD_DOT_0, NULL); 332 strcpy(buf, tmp); 333 PyMem_Free(tmp); 469 334 } 470 335 … … 472 337 PyFloat_AsReprString(char *buf, PyFloatObject *v) 473 338 { 474 format_float(buf, 100, v, PREC_REPR); 339 char * tmp = PyOS_double_to_string(v->ob_fval, 'r', 0, 340 Py_DTSF_ADD_DOT_0, NULL); 341 strcpy(buf, tmp); 342 PyMem_Free(tmp); 475 343 } 476 344 … … 479 347 float_print(PyFloatObject *v, FILE *fp, int flags) 480 348 { 481 char buf[100]; 482 format_float(buf, sizeof(buf), v, 483 (flags & Py_PRINT_RAW) ? PREC_STR : PREC_REPR); 484 Py_BEGIN_ALLOW_THREADS 485 fputs(buf, fp); 486 Py_END_ALLOW_THREADS 487 return 0; 349 char *buf; 350 if (flags & Py_PRINT_RAW) 351 buf = PyOS_double_to_string(v->ob_fval, 352 'g', PyFloat_STR_PRECISION, 353 Py_DTSF_ADD_DOT_0, NULL); 354 else 355 buf = PyOS_double_to_string(v->ob_fval, 356 'r', 0, Py_DTSF_ADD_DOT_0, NULL); 357 Py_BEGIN_ALLOW_THREADS 358 fputs(buf, fp); 359 Py_END_ALLOW_THREADS 360 PyMem_Free(buf); 361 return 0; 362 } 363 364 static PyObject * 365 float_str_or_repr(PyFloatObject *v, int precision, char format_code) 366 { 367 PyObject *result; 368 char *buf = PyOS_double_to_string(PyFloat_AS_DOUBLE(v), 369 format_code, precision, 370 Py_DTSF_ADD_DOT_0, 371 NULL); 372 if (!buf) 373 return PyErr_NoMemory(); 374 result = PyString_FromString(buf); 375 PyMem_Free(buf); 376 return result; 488 377 } 489 378 … … 491 380 float_repr(PyFloatObject *v) 492 381 { 493 char buf[100]; 494 format_float(buf, sizeof(buf), v, PREC_REPR); 495 496 return PyString_FromString(buf); 382 return float_str_or_repr(v, 0, 'r'); 497 383 } 498 384 … … 500 386 float_str(PyFloatObject *v) 501 387 { 502 char buf[100]; 503 format_float(buf, sizeof(buf), v, PREC_STR); 504 return PyString_FromString(buf); 388 return float_str_or_repr(v, PyFloat_STR_PRECISION, 'g'); 505 389 } 506 390 … … 523 407 float_richcompare(PyObject *v, PyObject *w, int op) 524 408 { 525 526 527 528 529 530 531 532 533 534 535 536 537 538 539 540 541 542 543 544 545 546 547 548 549 550 551 552 553 409 double i, j; 410 int r = 0; 411 412 assert(PyFloat_Check(v)); 413 i = PyFloat_AS_DOUBLE(v); 414 415 /* Switch on the type of w. Set i and j to doubles to be compared, 416 * and op to the richcomp to use. 417 */ 418 if (PyFloat_Check(w)) 419 j = PyFloat_AS_DOUBLE(w); 420 421 else if (!Py_IS_FINITE(i)) { 422 if (PyInt_Check(w) || PyLong_Check(w)) 423 /* If i is an infinity, its magnitude exceeds any 424 * finite integer, so it doesn't matter which int we 425 * compare i with. If i is a NaN, similarly. 426 */ 427 j = 0.0; 428 else 429 goto Unimplemented; 430 } 431 432 else if (PyInt_Check(w)) { 433 long jj = PyInt_AS_LONG(w); 434 /* In the worst realistic case I can imagine, C double is a 435 * Cray single with 48 bits of precision, and long has 64 436 * bits. 437 */ 554 438 #if SIZEOF_LONG > 6 555 556 557 558 559 560 561 562 563 564 565 566 567 568 439 unsigned long abs = (unsigned long)(jj < 0 ? -jj : jj); 440 if (abs >> 48) { 441 /* Needs more than 48 bits. Make it take the 442 * PyLong path. 443 */ 444 PyObject *result; 445 PyObject *ww = PyLong_FromLong(jj); 446 447 if (ww == NULL) 448 return NULL; 449 result = float_richcompare(v, ww, op); 450 Py_DECREF(ww); 451 return result; 452 } 569 453 #endif 570 571 572 573 574 575 576 577 578 579 580 581 582 583 584 585 586 587 588 589 590 591 592 593 594 595 596 597 598 599 600 601 602 603 604 605 606 607 608 609 610 611 612 613 614 615 616 617 618 619 620 621 622 623 624 625 626 627 628 629 630 631 632 633 634 635 636 637 638 639 640 641 642 643 644 645 646 647 648 649 650 651 652 653 654 655 656 657 658 659 660 661 662 663 664 665 666 667 668 669 670 671 672 673 674 675 676 677 678 679 680 681 682 683 684 685 686 687 688 689 690 691 692 693 694 695 696 697 698 699 700 701 702 703 else/* w isn't float, int, or long */704 454 j = (double)jj; 455 assert((long)j == jj); 456 } 457 458 else if (PyLong_Check(w)) { 459 int vsign = i == 0.0 ? 0 : i < 0.0 ? -1 : 1; 460 int wsign = _PyLong_Sign(w); 461 size_t nbits; 462 int exponent; 463 464 if (vsign != wsign) { 465 /* Magnitudes are irrelevant -- the signs alone 466 * determine the outcome. 467 */ 468 i = (double)vsign; 469 j = (double)wsign; 470 goto Compare; 471 } 472 /* The signs are the same. */ 473 /* Convert w to a double if it fits. In particular, 0 fits. */ 474 nbits = _PyLong_NumBits(w); 475 if (nbits == (size_t)-1 && PyErr_Occurred()) { 476 /* This long is so large that size_t isn't big enough 477 * to hold the # of bits. Replace with little doubles 478 * that give the same outcome -- w is so large that 479 * its magnitude must exceed the magnitude of any 480 * finite float. 481 */ 482 PyErr_Clear(); 483 i = (double)vsign; 484 assert(wsign != 0); 485 j = wsign * 2.0; 486 goto Compare; 487 } 488 if (nbits <= 48) { 489 j = PyLong_AsDouble(w); 490 /* It's impossible that <= 48 bits overflowed. */ 491 assert(j != -1.0 || ! PyErr_Occurred()); 492 goto Compare; 493 } 494 assert(wsign != 0); /* else nbits was 0 */ 495 assert(vsign != 0); /* if vsign were 0, then since wsign is 496 * not 0, we would have taken the 497 * vsign != wsign branch at the start */ 498 /* We want to work with non-negative numbers. */ 499 if (vsign < 0) { 500 /* "Multiply both sides" by -1; this also swaps the 501 * comparator. 502 */ 503 i = -i; 504 op = _Py_SwappedOp[op]; 505 } 506 assert(i > 0.0); 507 (void) frexp(i, &exponent); 508 /* exponent is the # of bits in v before the radix point; 509 * we know that nbits (the # of bits in w) > 48 at this point 510 */ 511 if (exponent < 0 || (size_t)exponent < nbits) { 512 i = 1.0; 513 j = 2.0; 514 goto Compare; 515 } 516 if ((size_t)exponent > nbits) { 517 i = 2.0; 518 j = 1.0; 519 goto Compare; 520 } 521 /* v and w have the same number of bits before the radix 522 * point. Construct two longs that have the same comparison 523 * outcome. 524 */ 525 { 526 double fracpart; 527 double intpart; 528 PyObject *result = NULL; 529 PyObject *one = NULL; 530 PyObject *vv = NULL; 531 PyObject *ww = w; 532 533 if (wsign < 0) { 534 ww = PyNumber_Negative(w); 535 if (ww == NULL) 536 goto Error; 537 } 538 else 539 Py_INCREF(ww); 540 541 fracpart = modf(i, &intpart); 542 vv = PyLong_FromDouble(intpart); 543 if (vv == NULL) 544 goto Error; 545 546 if (fracpart != 0.0) { 547 /* Shift left, and or a 1 bit into vv 548 * to represent the lost fraction. 549 */ 550 PyObject *temp; 551 552 one = PyInt_FromLong(1); 553 if (one == NULL) 554 goto Error; 555 556 temp = PyNumber_Lshift(ww, one); 557 if (temp == NULL) 558 goto Error; 559 Py_DECREF(ww); 560 ww = temp; 561 562 temp = PyNumber_Lshift(vv, one); 563 if (temp == NULL) 564 goto Error; 565 Py_DECREF(vv); 566 vv = temp; 567 568 temp = PyNumber_Or(vv, one); 569 if (temp == NULL) 570 goto Error; 571 Py_DECREF(vv); 572 vv = temp; 573 } 574 575 r = PyObject_RichCompareBool(vv, ww, op); 576 if (r < 0) 577 goto Error; 578 result = PyBool_FromLong(r); 579 Error: 580 Py_XDECREF(vv); 581 Py_XDECREF(ww); 582 Py_XDECREF(one); 583 return result; 584 } 585 } /* else if (PyLong_Check(w)) */ 586 587 else /* w isn't float, int, or long */ 588 goto Unimplemented; 705 589 706 590 Compare: 707 708 709 710 711 712 713 714 715 716 717 718 719 720 721 722 723 724 725 726 727 728 729 591 PyFPE_START_PROTECT("richcompare", return NULL) 592 switch (op) { 593 case Py_EQ: 594 r = i == j; 595 break; 596 case Py_NE: 597 r = i != j; 598 break; 599 case Py_LE: 600 r = i <= j; 601 break; 602 case Py_GE: 603 r = i >= j; 604 break; 605 case Py_LT: 606 r = i < j; 607 break; 608 case Py_GT: 609 r = i > j; 610 break; 611 } 612 PyFPE_END_PROTECT(r) 613 return PyBool_FromLong(r); 730 614 731 615 Unimplemented: 732 733 616 Py_INCREF(Py_NotImplemented); 617 return Py_NotImplemented; 734 618 } 735 619 … … 737 621 float_hash(PyFloatObject *v) 738 622 { 739 623 return _Py_HashDouble(v->ob_fval); 740 624 } 741 625 … … 743 627 float_add(PyObject *v, PyObject *w) 744 628 { 745 746 747 748 749 750 751 629 double a,b; 630 CONVERT_TO_DOUBLE(v, a); 631 CONVERT_TO_DOUBLE(w, b); 632 PyFPE_START_PROTECT("add", return 0) 633 a = a + b; 634 PyFPE_END_PROTECT(a) 635 return PyFloat_FromDouble(a); 752 636 } 753 637 … … 755 639 float_sub(PyObject *v, PyObject *w) 756 640 { 757 758 759 760 761 762 763 641 double a,b; 642 CONVERT_TO_DOUBLE(v, a); 643 CONVERT_TO_DOUBLE(w, b); 644 PyFPE_START_PROTECT("subtract", return 0) 645 a = a - b; 646 PyFPE_END_PROTECT(a) 647 return PyFloat_FromDouble(a); 764 648 } 765 649 … … 767 651 float_mul(PyObject *v, PyObject *w) 768 652 { 769 770 771 772 773 774 775 653 double a,b; 654 CONVERT_TO_DOUBLE(v, a); 655 CONVERT_TO_DOUBLE(w, b); 656 PyFPE_START_PROTECT("multiply", return 0) 657 a = a * b; 658 PyFPE_END_PROTECT(a) 659 return PyFloat_FromDouble(a); 776 660 } 777 661 … … 779 663 float_div(PyObject *v, PyObject *w) 780 664 { 781 782 783 665 double a,b; 666 CONVERT_TO_DOUBLE(v, a); 667 CONVERT_TO_DOUBLE(w, b); 784 668 #ifdef Py_NAN 785 786 787 "float division");788 789 669 if (b == 0.0) { 670 PyErr_SetString(PyExc_ZeroDivisionError, 671 "float division by zero"); 672 return NULL; 673 } 790 674 #endif 791 792 793 794 675 PyFPE_START_PROTECT("divide", return 0) 676 a = a / b; 677 PyFPE_END_PROTECT(a) 678 return PyFloat_FromDouble(a); 795 679 } 796 680 … … 798 682 float_classic_div(PyObject *v, PyObject *w) 799 683 { 800 801 802 803 804 805 684 double a,b; 685 CONVERT_TO_DOUBLE(v, a); 686 CONVERT_TO_DOUBLE(w, b); 687 if (Py_DivisionWarningFlag >= 2 && 688 PyErr_Warn(PyExc_DeprecationWarning, "classic float division") < 0) 689 return NULL; 806 690 #ifdef Py_NAN 807 808 809 "float division");810 811 691 if (b == 0.0) { 692 PyErr_SetString(PyExc_ZeroDivisionError, 693 "float division by zero"); 694 return NULL; 695 } 812 696 #endif 813 814 815 816 697 PyFPE_START_PROTECT("divide", return 0) 698 a = a / b; 699 PyFPE_END_PROTECT(a) 700 return PyFloat_FromDouble(a); 817 701 } 818 702 … … 820 704 float_rem(PyObject *v, PyObject *w) 821 705 { 822 823 824 825 706 double vx, wx; 707 double mod; 708 CONVERT_TO_DOUBLE(v, vx); 709 CONVERT_TO_DOUBLE(w, wx); 826 710 #ifdef Py_NAN 827 828 829 830 831 711 if (wx == 0.0) { 712 PyErr_SetString(PyExc_ZeroDivisionError, 713 "float modulo"); 714 return NULL; 715 } 832 716 #endif 833 PyFPE_START_PROTECT("modulo", return 0) 834 mod = fmod(vx, wx); 835 /* note: checking mod*wx < 0 is incorrect -- underflows to 836 0 if wx < sqrt(smallest nonzero double) */ 837 if (mod && ((wx < 0) != (mod < 0))) { 838 mod += wx; 839 } 840 PyFPE_END_PROTECT(mod) 841 return PyFloat_FromDouble(mod); 717 PyFPE_START_PROTECT("modulo", return 0) 718 mod = fmod(vx, wx); 719 if (mod) { 720 /* ensure the remainder has the same sign as the denominator */ 721 if ((wx < 0) != (mod < 0)) { 722 mod += wx; 723 } 724 } 725 else { 726 /* the remainder is zero, and in the presence of signed zeroes 727 fmod returns different results across platforms; ensure 728 it has the same sign as the denominator; we'd like to do 729 "mod = wx * 0.0", but that may get optimized away */ 730 mod *= mod; /* hide "mod = +0" from optimizer */ 731 if (wx < 0.0) 732 mod = -mod; 733 } 734 PyFPE_END_PROTECT(mod) 735 return PyFloat_FromDouble(mod); 842 736 } 843 737 … … 845 739 float_divmod(PyObject *v, PyObject *w) 846 740 { 847 848 849 850 851 852 853 854 855 856 857 858 859 860 861 862 863 864 865 866 867 868 869 870 871 872 873 874 875 876 877 878 879 880 881 882 883 884 885 886 887 888 div *= div;/* hide "div = +0" from optimizers */889 890 891 892 741 double vx, wx; 742 double div, mod, floordiv; 743 CONVERT_TO_DOUBLE(v, vx); 744 CONVERT_TO_DOUBLE(w, wx); 745 if (wx == 0.0) { 746 PyErr_SetString(PyExc_ZeroDivisionError, "float divmod()"); 747 return NULL; 748 } 749 PyFPE_START_PROTECT("divmod", return 0) 750 mod = fmod(vx, wx); 751 /* fmod is typically exact, so vx-mod is *mathematically* an 752 exact multiple of wx. But this is fp arithmetic, and fp 753 vx - mod is an approximation; the result is that div may 754 not be an exact integral value after the division, although 755 it will always be very close to one. 756 */ 757 div = (vx - mod) / wx; 758 if (mod) { 759 /* ensure the remainder has the same sign as the denominator */ 760 if ((wx < 0) != (mod < 0)) { 761 mod += wx; 762 div -= 1.0; 763 } 764 } 765 else { 766 /* the remainder is zero, and in the presence of signed zeroes 767 fmod returns different results across platforms; ensure 768 it has the same sign as the denominator; we'd like to do 769 "mod = wx * 0.0", but that may get optimized away */ 770 mod *= mod; /* hide "mod = +0" from optimizer */ 771 if (wx < 0.0) 772 mod = -mod; 773 } 774 /* snap quotient to nearest integral value */ 775 if (div) { 776 floordiv = floor(div); 777 if (div - floordiv > 0.5) 778 floordiv += 1.0; 779 } 780 else { 781 /* div is zero - get the same sign as the true quotient */ 782 div *= div; /* hide "div = +0" from optimizers */ 783 floordiv = div * vx / wx; /* zero w/ sign of vx/wx */ 784 } 785 PyFPE_END_PROTECT(floordiv) 786 return Py_BuildValue("(dd)", floordiv, mod); 893 787 } 894 788 … … 896 790 float_floor_div(PyObject *v, PyObject *w) 897 791 { 898 PyObject *t, *r; 899 900 t = float_divmod(v, w); 901 if (t == NULL || t == Py_NotImplemented) 902 return t; 903 assert(PyTuple_CheckExact(t)); 904 r = PyTuple_GET_ITEM(t, 0); 905 Py_INCREF(r); 906 Py_DECREF(t); 907 return r; 908 } 792 PyObject *t, *r; 793 794 t = float_divmod(v, w); 795 if (t == NULL || t == Py_NotImplemented) 796 return t; 797 assert(PyTuple_CheckExact(t)); 798 r = PyTuple_GET_ITEM(t, 0); 799 Py_INCREF(r); 800 Py_DECREF(t); 801 return r; 802 } 803 804 /* determine whether x is an odd integer or not; assumes that 805 x is not an infinity or nan. */ 806 #define DOUBLE_IS_ODD_INTEGER(x) (fmod(fabs(x), 2.0) == 1.0) 909 807 910 808 static PyObject * 911 809 float_pow(PyObject *v, PyObject *w, PyObject *z) 912 810 { 913 double iv, iw, ix; 914 915 if ((PyObject *)z != Py_None) { 916 PyErr_SetString(PyExc_TypeError, "pow() 3rd argument not " 917 "allowed unless all arguments are integers"); 918 return NULL; 919 } 920 921 CONVERT_TO_DOUBLE(v, iv); 922 CONVERT_TO_DOUBLE(w, iw); 923 924 /* Sort out special cases here instead of relying on pow() */ 925 if (iw == 0) { /* v**0 is 1, even 0**0 */ 926 return PyFloat_FromDouble(1.0); 927 } 928 if (iv == 0.0) { /* 0**w is error if w<0, else 1 */ 929 if (iw < 0.0) { 930 PyErr_SetString(PyExc_ZeroDivisionError, 931 "0.0 cannot be raised to a negative power"); 932 return NULL; 933 } 934 return PyFloat_FromDouble(0.0); 935 } 936 if (iv == 1.0) { /* 1**w is 1, even 1**inf and 1**nan */ 937 return PyFloat_FromDouble(1.0); 938 } 939 if (iv < 0.0) { 940 /* Whether this is an error is a mess, and bumps into libm 941 * bugs so we have to figure it out ourselves. 942 */ 943 if (iw != floor(iw)) { 944 PyErr_SetString(PyExc_ValueError, "negative number " 945 "cannot be raised to a fractional power"); 946 return NULL; 947 } 948 /* iw is an exact integer, albeit perhaps a very large one. 949 * -1 raised to an exact integer should never be exceptional. 950 * Alas, some libms (chiefly glibc as of early 2003) return 951 * NaN and set EDOM on pow(-1, large_int) if the int doesn't 952 * happen to be representable in a *C* integer. That's a 953 * bug; we let that slide in math.pow() (which currently 954 * reflects all platform accidents), but not for Python's **. 955 */ 956 if (iv == -1.0 && Py_IS_FINITE(iw)) { 957 /* Return 1 if iw is even, -1 if iw is odd; there's 958 * no guarantee that any C integral type is big 959 * enough to hold iw, so we have to check this 960 * indirectly. 961 */ 962 ix = floor(iw * 0.5) * 2.0; 963 return PyFloat_FromDouble(ix == iw ? 1.0 : -1.0); 964 } 965 /* Else iv != -1.0, and overflow or underflow are possible. 966 * Unless we're to write pow() ourselves, we have to trust 967 * the platform to do this correctly. 968 */ 969 } 970 errno = 0; 971 PyFPE_START_PROTECT("pow", return NULL) 972 ix = pow(iv, iw); 973 PyFPE_END_PROTECT(ix) 974 Py_ADJUST_ERANGE1(ix); 975 if (errno != 0) { 976 /* We don't expect any errno value other than ERANGE, but 977 * the range of libm bugs appears unbounded. 978 */ 979 PyErr_SetFromErrno(errno == ERANGE ? PyExc_OverflowError : 980 PyExc_ValueError); 981 return NULL; 982 } 983 return PyFloat_FromDouble(ix); 984 } 811 double iv, iw, ix; 812 int negate_result = 0; 813 814 if ((PyObject *)z != Py_None) { 815 PyErr_SetString(PyExc_TypeError, "pow() 3rd argument not " 816 "allowed unless all arguments are integers"); 817 return NULL; 818 } 819 820 CONVERT_TO_DOUBLE(v, iv); 821 CONVERT_TO_DOUBLE(w, iw); 822 823 /* Sort out special cases here instead of relying on pow() */ 824 if (iw == 0) { /* v**0 is 1, even 0**0 */ 825 return PyFloat_FromDouble(1.0); 826 } 827 if (Py_IS_NAN(iv)) { /* nan**w = nan, unless w == 0 */ 828 return PyFloat_FromDouble(iv); 829 } 830 if (Py_IS_NAN(iw)) { /* v**nan = nan, unless v == 1; 1**nan = 1 */ 831 return PyFloat_FromDouble(iv == 1.0 ? 1.0 : iw); 832 } 833 if (Py_IS_INFINITY(iw)) { 834 /* v**inf is: 0.0 if abs(v) < 1; 1.0 if abs(v) == 1; inf if 835 * abs(v) > 1 (including case where v infinite) 836 * 837 * v**-inf is: inf if abs(v) < 1; 1.0 if abs(v) == 1; 0.0 if 838 * abs(v) > 1 (including case where v infinite) 839 */ 840 iv = fabs(iv); 841 if (iv == 1.0) 842 return PyFloat_FromDouble(1.0); 843 else if ((iw > 0.0) == (iv > 1.0)) 844 return PyFloat_FromDouble(fabs(iw)); /* return inf */ 845 else 846 return PyFloat_FromDouble(0.0); 847 } 848 if (Py_IS_INFINITY(iv)) { 849 /* (+-inf)**w is: inf for w positive, 0 for w negative; in 850 * both cases, we need to add the appropriate sign if w is 851 * an odd integer. 852 */ 853 int iw_is_odd = DOUBLE_IS_ODD_INTEGER(iw); 854 if (iw > 0.0) 855 return PyFloat_FromDouble(iw_is_odd ? iv : fabs(iv)); 856 else 857 return PyFloat_FromDouble(iw_is_odd ? 858 copysign(0.0, iv) : 0.0); 859 } 860 if (iv == 0.0) { /* 0**w is: 0 for w positive, 1 for w zero 861 (already dealt with above), and an error 862 if w is negative. */ 863 int iw_is_odd = DOUBLE_IS_ODD_INTEGER(iw); 864 if (iw < 0.0) { 865 PyErr_SetString(PyExc_ZeroDivisionError, 866 "0.0 cannot be raised to a " 867 "negative power"); 868 return NULL; 869 } 870 /* use correct sign if iw is odd */ 871 return PyFloat_FromDouble(iw_is_odd ? iv : 0.0); 872 } 873 874 if (iv < 0.0) { 875 /* Whether this is an error is a mess, and bumps into libm 876 * bugs so we have to figure it out ourselves. 877 */ 878 if (iw != floor(iw)) { 879 PyErr_SetString(PyExc_ValueError, "negative number " 880 "cannot be raised to a fractional power"); 881 return NULL; 882 } 883 /* iw is an exact integer, albeit perhaps a very large 884 * one. Replace iv by its absolute value and remember 885 * to negate the pow result if iw is odd. 886 */ 887 iv = -iv; 888 negate_result = DOUBLE_IS_ODD_INTEGER(iw); 889 } 890 891 if (iv == 1.0) { /* 1**w is 1, even 1**inf and 1**nan */ 892 /* (-1) ** large_integer also ends up here. Here's an 893 * extract from the comments for the previous 894 * implementation explaining why this special case is 895 * necessary: 896 * 897 * -1 raised to an exact integer should never be exceptional. 898 * Alas, some libms (chiefly glibc as of early 2003) return 899 * NaN and set EDOM on pow(-1, large_int) if the int doesn't 900 * happen to be representable in a *C* integer. That's a 901 * bug. 902 */ 903 return PyFloat_FromDouble(negate_result ? -1.0 : 1.0); 904 } 905 906 /* Now iv and iw are finite, iw is nonzero, and iv is 907 * positive and not equal to 1.0. We finally allow 908 * the platform pow to step in and do the rest. 909 */ 910 errno = 0; 911 PyFPE_START_PROTECT("pow", return NULL) 912 ix = pow(iv, iw); 913 PyFPE_END_PROTECT(ix) 914 Py_ADJUST_ERANGE1(ix); 915 if (negate_result) 916 ix = -ix; 917 918 if (errno != 0) { 919 /* We don't expect any errno value other than ERANGE, but 920 * the range of libm bugs appears unbounded. 921 */ 922 PyErr_SetFromErrno(errno == ERANGE ? PyExc_OverflowError : 923 PyExc_ValueError); 924 return NULL; 925 } 926 return PyFloat_FromDouble(ix); 927 } 928 929 #undef DOUBLE_IS_ODD_INTEGER 985 930 986 931 static PyObject * 987 932 float_neg(PyFloatObject *v) 988 933 { 989 934 return PyFloat_FromDouble(-v->ob_fval); 990 935 } 991 936 … … 993 938 float_abs(PyFloatObject *v) 994 939 { 995 940 return PyFloat_FromDouble(fabs(v->ob_fval)); 996 941 } 997 942 … … 999 944 float_nonzero(PyFloatObject *v) 1000 945 { 1001 946 return v->ob_fval != 0.0; 1002 947 } 1003 948 … … 1005 950 float_coerce(PyObject **pv, PyObject **pw) 1006 951 { 1007 1008 1009 1010 1011 1012 1013 1014 1015 1016 1017 1018 1019 1020 1021 1022 1023 1024 1025 1026 952 if (PyInt_Check(*pw)) { 953 long x = PyInt_AsLong(*pw); 954 *pw = PyFloat_FromDouble((double)x); 955 Py_INCREF(*pv); 956 return 0; 957 } 958 else if (PyLong_Check(*pw)) { 959 double x = PyLong_AsDouble(*pw); 960 if (x == -1.0 && PyErr_Occurred()) 961 return -1; 962 *pw = PyFloat_FromDouble(x); 963 Py_INCREF(*pv); 964 return 0; 965 } 966 else if (PyFloat_Check(*pw)) { 967 Py_INCREF(*pv); 968 Py_INCREF(*pw); 969 return 0; 970 } 971 return 1; /* Can't do it */ 1027 972 } 1028 973 … … 1030 975 float_is_integer(PyObject *v) 1031 976 { 1032 1033 1034 1035 1036 1037 1038 1039 1040 1041 1042 1043 1044 1045 1046 1047 1048 1049 977 double x = PyFloat_AsDouble(v); 978 PyObject *o; 979 980 if (x == -1.0 && PyErr_Occurred()) 981 return NULL; 982 if (!Py_IS_FINITE(x)) 983 Py_RETURN_FALSE; 984 errno = 0; 985 PyFPE_START_PROTECT("is_integer", return NULL) 986 o = (floor(x) == x) ? Py_True : Py_False; 987 PyFPE_END_PROTECT(x) 988 if (errno != 0) { 989 PyErr_SetFromErrno(errno == ERANGE ? PyExc_OverflowError : 990 PyExc_ValueError); 991 return NULL; 992 } 993 Py_INCREF(o); 994 return o; 1050 995 } 1051 996 … … 1054 999 float_is_inf(PyObject *v) 1055 1000 { 1056 1057 1058 1059 1001 double x = PyFloat_AsDouble(v); 1002 if (x == -1.0 && PyErr_Occurred()) 1003 return NULL; 1004 return PyBool_FromLong((long)Py_IS_INFINITY(x)); 1060 1005 } 1061 1006 … … 1063 1008 float_is_nan(PyObject *v) 1064 1009 { 1065 1066 1067 1068 1010 double x = PyFloat_AsDouble(v); 1011 if (x == -1.0 && PyErr_Occurred()) 1012 return NULL; 1013 return PyBool_FromLong((long)Py_IS_NAN(x)); 1069 1014 } 1070 1015 … … 1072 1017 float_is_finite(PyObject *v) 1073 1018 { 1074 1075 1076 1077 1019 double x = PyFloat_AsDouble(v); 1020 if (x == -1.0 && PyErr_Occurred()) 1021 return NULL; 1022 return PyBool_FromLong((long)Py_IS_FINITE(x)); 1078 1023 } 1079 1024 #endif … … 1082 1027 float_trunc(PyObject *v) 1083 1028 { 1084 double x = PyFloat_AsDouble(v); 1085 double wholepart; /* integral portion of x, rounded toward 0 */ 1086 1087 (void)modf(x, &wholepart); 1088 /* Try to get out cheap if this fits in a Python int. The attempt 1089 * to cast to long must be protected, as C doesn't define what 1090 * happens if the double is too big to fit in a long. Some rare 1091 * systems raise an exception then (RISCOS was mentioned as one, 1092 * and someone using a non-default option on Sun also bumped into 1093 * that). Note that checking for >= and <= LONG_{MIN,MAX} would 1094 * still be vulnerable: if a long has more bits of precision than 1095 * a double, casting MIN/MAX to double may yield an approximation, 1096 * and if that's rounded up, then, e.g., wholepart=LONG_MAX+1 would 1097 * yield true from the C expression wholepart<=LONG_MAX, despite 1098 * that wholepart is actually greater than LONG_MAX. 1099 */ 1100 if (LONG_MIN < wholepart && wholepart < LONG_MAX) { 1101 const long aslong = (long)wholepart; 1102 return PyInt_FromLong(aslong); 1103 } 1104 return PyLong_FromDouble(wholepart); 1029 double x = PyFloat_AsDouble(v); 1030 double wholepart; /* integral portion of x, rounded toward 0 */ 1031 1032 (void)modf(x, &wholepart); 1033 /* Try to get out cheap if this fits in a Python int. The attempt 1034 * to cast to long must be protected, as C doesn't define what 1035 * happens if the double is too big to fit in a long. Some rare 1036 * systems raise an exception then (RISCOS was mentioned as one, 1037 * and someone using a non-default option on Sun also bumped into 1038 * that). Note that checking for <= LONG_MAX is unsafe: if a long 1039 * has more bits of precision than a double, casting LONG_MAX to 1040 * double may yield an approximation, and if that's rounded up, 1041 * then, e.g., wholepart=LONG_MAX+1 would yield true from the C 1042 * expression wholepart<=LONG_MAX, despite that wholepart is 1043 * actually greater than LONG_MAX. However, assuming a two's complement 1044 * machine with no trap representation, LONG_MIN will be a power of 2 (and 1045 * hence exactly representable as a double), and LONG_MAX = -1-LONG_MIN, so 1046 * the comparisons with (double)LONG_MIN below should be safe. 1047 */ 1048 if ((double)LONG_MIN <= wholepart && wholepart < -(double)LONG_MIN) { 1049 const long aslong = (long)wholepart; 1050 return PyInt_FromLong(aslong); 1051 } 1052 return PyLong_FromDouble(wholepart); 1105 1053 } 1106 1054 … … 1108 1056 float_long(PyObject *v) 1109 1057 { 1110 double x = PyFloat_AsDouble(v); 1111 return PyLong_FromDouble(x); 1112 } 1058 double x = PyFloat_AsDouble(v); 1059 return PyLong_FromDouble(x); 1060 } 1061 1062 /* _Py_double_round: rounds a finite nonzero double to the closest multiple of 1063 10**-ndigits; here ndigits is within reasonable bounds (typically, -308 <= 1064 ndigits <= 323). Returns a Python float, or sets a Python error and 1065 returns NULL on failure (OverflowError and memory errors are possible). */ 1066 1067 #ifndef PY_NO_SHORT_FLOAT_REPR 1068 /* version of _Py_double_round that uses the correctly-rounded string<->double 1069 conversions from Python/dtoa.c */ 1070 1071 /* FIVE_POW_LIMIT is the largest k such that 5**k is exactly representable as 1072 a double. Since we're using the code in Python/dtoa.c, it should be safe 1073 to assume that C doubles are IEEE 754 binary64 format. To be on the safe 1074 side, we check this. */ 1075 #if DBL_MANT_DIG == 53 1076 #define FIVE_POW_LIMIT 22 1077 #else 1078 #error "C doubles do not appear to be IEEE 754 binary64 format" 1079 #endif 1080 1081 PyObject * 1082 _Py_double_round(double x, int ndigits) { 1083 1084 double rounded, m; 1085 Py_ssize_t buflen, mybuflen=100; 1086 char *buf, *buf_end, shortbuf[100], *mybuf=shortbuf; 1087 int decpt, sign, val, halfway_case; 1088 PyObject *result = NULL; 1089 _Py_SET_53BIT_PRECISION_HEADER; 1090 1091 /* Easy path for the common case ndigits == 0. */ 1092 if (ndigits == 0) { 1093 rounded = round(x); 1094 if (fabs(rounded - x) == 0.5) 1095 /* halfway between two integers; use round-away-from-zero */ 1096 rounded = x + (x > 0.0 ? 0.5 : -0.5); 1097 return PyFloat_FromDouble(rounded); 1098 } 1099 1100 /* The basic idea is very simple: convert and round the double to a 1101 decimal string using _Py_dg_dtoa, then convert that decimal string 1102 back to a double with _Py_dg_strtod. There's one minor difficulty: 1103 Python 2.x expects round to do round-half-away-from-zero, while 1104 _Py_dg_dtoa does round-half-to-even. So we need some way to detect 1105 and correct the halfway cases. 1106 1107 Detection: a halfway value has the form k * 0.5 * 10**-ndigits for 1108 some odd integer k. Or in other words, a rational number x is 1109 exactly halfway between two multiples of 10**-ndigits if its 1110 2-valuation is exactly -ndigits-1 and its 5-valuation is at least 1111 -ndigits. For ndigits >= 0 the latter condition is automatically 1112 satisfied for a binary float x, since any such float has 1113 nonnegative 5-valuation. For 0 > ndigits >= -22, x needs to be an 1114 integral multiple of 5**-ndigits; we can check this using fmod. 1115 For -22 > ndigits, there are no halfway cases: 5**23 takes 54 bits 1116 to represent exactly, so any odd multiple of 0.5 * 10**n for n >= 1117 23 takes at least 54 bits of precision to represent exactly. 1118 1119 Correction: a simple strategy for dealing with halfway cases is to 1120 (for the halfway cases only) call _Py_dg_dtoa with an argument of 1121 ndigits+1 instead of ndigits (thus doing an exact conversion to 1122 decimal), round the resulting string manually, and then convert 1123 back using _Py_dg_strtod. 1124 */ 1125 1126 /* nans, infinities and zeros should have already been dealt 1127 with by the caller (in this case, builtin_round) */ 1128 assert(Py_IS_FINITE(x) && x != 0.0); 1129 1130 /* find 2-valuation val of x */ 1131 m = frexp(x, &val); 1132 while (m != floor(m)) { 1133 m *= 2.0; 1134 val--; 1135 } 1136 1137 /* determine whether this is a halfway case */ 1138 if (val == -ndigits-1) { 1139 if (ndigits >= 0) 1140 halfway_case = 1; 1141 else if (ndigits >= -FIVE_POW_LIMIT) { 1142 double five_pow = 1.0; 1143 int i; 1144 for (i=0; i < -ndigits; i++) 1145 five_pow *= 5.0; 1146 halfway_case = fmod(x, five_pow) == 0.0; 1147 } 1148 else 1149 halfway_case = 0; 1150 } 1151 else 1152 halfway_case = 0; 1153 1154 /* round to a decimal string; use an extra place for halfway case */ 1155 _Py_SET_53BIT_PRECISION_START; 1156 buf = _Py_dg_dtoa(x, 3, ndigits+halfway_case, &decpt, &sign, &buf_end); 1157 _Py_SET_53BIT_PRECISION_END; 1158 if (buf == NULL) { 1159 PyErr_NoMemory(); 1160 return NULL; 1161 } 1162 buflen = buf_end - buf; 1163 1164 /* in halfway case, do the round-half-away-from-zero manually */ 1165 if (halfway_case) { 1166 int i, carry; 1167 /* sanity check: _Py_dg_dtoa should not have stripped 1168 any zeros from the result: there should be exactly 1169 ndigits+1 places following the decimal point, and 1170 the last digit in the buffer should be a '5'.*/ 1171 assert(buflen - decpt == ndigits+1); 1172 assert(buf[buflen-1] == '5'); 1173 1174 /* increment and shift right at the same time. */ 1175 decpt += 1; 1176 carry = 1; 1177 for (i=buflen-1; i-- > 0;) { 1178 carry += buf[i] - '0'; 1179 buf[i+1] = carry % 10 + '0'; 1180 carry /= 10; 1181 } 1182 buf[0] = carry + '0'; 1183 } 1184 1185 /* Get new buffer if shortbuf is too small. Space needed <= buf_end - 1186 buf + 8: (1 extra for '0', 1 for sign, 5 for exp, 1 for '\0'). */ 1187 if (buflen + 8 > mybuflen) { 1188 mybuflen = buflen+8; 1189 mybuf = (char *)PyMem_Malloc(mybuflen); 1190 if (mybuf == NULL) { 1191 PyErr_NoMemory(); 1192 goto exit; 1193 } 1194 } 1195 /* copy buf to mybuf, adding exponent, sign and leading 0 */ 1196 PyOS_snprintf(mybuf, mybuflen, "%s0%se%d", (sign ? "-" : ""), 1197 buf, decpt - (int)buflen); 1198 1199 /* and convert the resulting string back to a double */ 1200 errno = 0; 1201 _Py_SET_53BIT_PRECISION_START; 1202 rounded = _Py_dg_strtod(mybuf, NULL); 1203 _Py_SET_53BIT_PRECISION_END; 1204 if (errno == ERANGE && fabs(rounded) >= 1.) 1205 PyErr_SetString(PyExc_OverflowError, 1206 "rounded value too large to represent"); 1207 else 1208 result = PyFloat_FromDouble(rounded); 1209 1210 /* done computing value; now clean up */ 1211 if (mybuf != shortbuf) 1212 PyMem_Free(mybuf); 1213 exit: 1214 _Py_dg_freedtoa(buf); 1215 return result; 1216 } 1217 1218 #undef FIVE_POW_LIMIT 1219 1220 #else /* PY_NO_SHORT_FLOAT_REPR */ 1221 1222 /* fallback version, to be used when correctly rounded binary<->decimal 1223 conversions aren't available */ 1224 1225 PyObject * 1226 _Py_double_round(double x, int ndigits) { 1227 double pow1, pow2, y, z; 1228 if (ndigits >= 0) { 1229 if (ndigits > 22) { 1230 /* pow1 and pow2 are each safe from overflow, but 1231 pow1*pow2 ~= pow(10.0, ndigits) might overflow */ 1232 pow1 = pow(10.0, (double)(ndigits-22)); 1233 pow2 = 1e22; 1234 } 1235 else { 1236 pow1 = pow(10.0, (double)ndigits); 1237 pow2 = 1.0; 1238 } 1239 y = (x*pow1)*pow2; 1240 /* if y overflows, then rounded value is exactly x */ 1241 if (!Py_IS_FINITE(y)) 1242 return PyFloat_FromDouble(x); 1243 } 1244 else { 1245 pow1 = pow(10.0, (double)-ndigits); 1246 pow2 = 1.0; /* unused; silences a gcc compiler warning */ 1247 y = x / pow1; 1248 } 1249 1250 z = round(y); 1251 if (fabs(y-z) == 0.5) 1252 /* halfway between two integers; use round-away-from-zero */ 1253 z = y + copysign(0.5, y); 1254 1255 if (ndigits >= 0) 1256 z = (z / pow2) / pow1; 1257 else 1258 z *= pow1; 1259 1260 /* if computation resulted in overflow, raise OverflowError */ 1261 if (!Py_IS_FINITE(z)) { 1262 PyErr_SetString(PyExc_OverflowError, 1263 "overflow occurred during round"); 1264 return NULL; 1265 } 1266 1267 return PyFloat_FromDouble(z); 1268 } 1269 1270 #endif /* PY_NO_SHORT_FLOAT_REPR */ 1113 1271 1114 1272 static PyObject * 1115 1273 float_float(PyObject *v) 1116 1274 { 1117 1118 1119 1120 1121 1275 if (PyFloat_CheckExact(v)) 1276 Py_INCREF(v); 1277 else 1278 v = PyFloat_FromDouble(((PyFloatObject *)v)->ob_fval); 1279 return v; 1122 1280 } 1123 1281 … … 1127 1285 char_from_hex(int x) 1128 1286 { 1129 1130 1287 assert(0 <= x && x < 16); 1288 return "0123456789abcdef"[x]; 1131 1289 } 1132 1290 1133 1291 static int 1134 1292 hex_from_char(char c) { 1135 1136 1137 1138 1139 1140 1141 1142 1143 1144 1145 1146 1147 1148 1149 1150 1151 1152 1153 1154 1155 1156 1157 1158 1159 1160 1161 1162 1163 1164 1165 1166 1167 1168 1169 1170 1171 1172 1173 1174 1175 1176 1177 1178 1179 1180 1181 1182 1183 1184 1185 1186 1187 1188 1189 1190 1191 1192 1193 1194 1195 1293 int x; 1294 switch(c) { 1295 case '0': 1296 x = 0; 1297 break; 1298 case '1': 1299 x = 1; 1300 break; 1301 case '2': 1302 x = 2; 1303 break; 1304 case '3': 1305 x = 3; 1306 break; 1307 case '4': 1308 x = 4; 1309 break; 1310 case '5': 1311 x = 5; 1312 break; 1313 case '6': 1314 x = 6; 1315 break; 1316 case '7': 1317 x = 7; 1318 break; 1319 case '8': 1320 x = 8; 1321 break; 1322 case '9': 1323 x = 9; 1324 break; 1325 case 'a': 1326 case 'A': 1327 x = 10; 1328 break; 1329 case 'b': 1330 case 'B': 1331 x = 11; 1332 break; 1333 case 'c': 1334 case 'C': 1335 x = 12; 1336 break; 1337 case 'd': 1338 case 'D': 1339 x = 13; 1340 break; 1341 case 'e': 1342 case 'E': 1343 x = 14; 1344 break; 1345 case 'f': 1346 case 'F': 1347 x = 15; 1348 break; 1349 default: 1350 x = -1; 1351 break; 1352 } 1353 return x; 1196 1354 } 1197 1355 … … 1205 1363 float_hex(PyObject *v) 1206 1364 { 1207 1208 1209 1210 1211 1212 1213 1214 1215 1216 1217 1218 1219 if(copysign(1.0, x) == -1.0)1220 1221 1222 1223 1224 1225 1226 1227 1228 1229 1230 1231 1232 1233 1234 1235 1236 1237 1238 1239 1240 1241 1242 1243 1244 1245 1246 1247 1248 1249 1250 1251 1252 1253 1254 1365 double x, m; 1366 int e, shift, i, si, esign; 1367 /* Space for 1+(TOHEX_NBITS-1)/4 digits, a decimal point, and the 1368 trailing NUL byte. */ 1369 char s[(TOHEX_NBITS-1)/4+3]; 1370 1371 CONVERT_TO_DOUBLE(v, x); 1372 1373 if (Py_IS_NAN(x) || Py_IS_INFINITY(x)) 1374 return float_str((PyFloatObject *)v); 1375 1376 if (x == 0.0) { 1377 if (copysign(1.0, x) == -1.0) 1378 return PyString_FromString("-0x0.0p+0"); 1379 else 1380 return PyString_FromString("0x0.0p+0"); 1381 } 1382 1383 m = frexp(fabs(x), &e); 1384 shift = 1 - MAX(DBL_MIN_EXP - e, 0); 1385 m = ldexp(m, shift); 1386 e -= shift; 1387 1388 si = 0; 1389 s[si] = char_from_hex((int)m); 1390 si++; 1391 m -= (int)m; 1392 s[si] = '.'; 1393 si++; 1394 for (i=0; i < (TOHEX_NBITS-1)/4; i++) { 1395 m *= 16.0; 1396 s[si] = char_from_hex((int)m); 1397 si++; 1398 m -= (int)m; 1399 } 1400 s[si] = '\0'; 1401 1402 if (e < 0) { 1403 esign = (int)'-'; 1404 e = -e; 1405 } 1406 else 1407 esign = (int)'+'; 1408 1409 if (x < 0.0) 1410 return PyString_FromFormat("-0x%sp%c%d", s, esign, e); 1411 else 1412 return PyString_FromFormat("0x%sp%c%d", s, esign, e); 1255 1413 } 1256 1414 … … 1264 1422 '0x1.921f9f01b866ep+1'"); 1265 1423 1266 /* Case-insensitive string match used for nan and inf detection. t should be1267 lower-case and null-terminated. Return a nonzero result if the first1268 strlen(t) characters of s match t and 0 otherwise. */1424 /* Case-insensitive locale-independent string match used for nan and inf 1425 detection. t should be lower-case and null-terminated. Return a nonzero 1426 result if the first strlen(t) characters of s match t and 0 otherwise. */ 1269 1427 1270 1428 static int 1271 1429 case_insensitive_match(const char *s, const char *t) 1272 1430 { 1273 while(*t && tolower(*s) == *t) {1274 1275 1276 1277 1431 while(*t && Py_TOLOWER(*s) == *t) { 1432 s++; 1433 t++; 1434 } 1435 return *t ? 0 : 1; 1278 1436 } 1279 1437 … … 1283 1441 float_fromhex(PyObject *cls, PyObject *arg) 1284 1442 { 1285 1286 1287 1288 1289 1290 1291 1292 1293 1294 1295 1296 1297 1298 1299 1300 1301 1302 1303 1304 1305 1306 1307 1308 1309 1310 1311 1312 1313 1314 1315 1316 1317 1318 1319 1320 1321 1322 1323 1324 1325 1326 1327 1328 1329 1330 1331 1332 1333 1334 1335 1336 1337 1338 1339 1340 1341 1342 1343 1344 1345 1346 while (*s && isspace(Py_CHARMASK(*s)))1347 1348 1349 1350 1351 1352 1353 1354 1355 1356 1357 1358 1359 1360 1361 1362 1363 1364 1365 1366 1367 1368 1369 1370 1371 1372 1373 1374 1375 1376 1377 if (tolower(*s) == (int)'x')1378 1379 1380 1381 1382 1383 1384 1385 1386 1387 1388 1389 1390 1391 1392 1393 1394 1395 1396 1397 1398 1399 1400 1401 1402 1403 1404 1405 1406 1407 if (tolower(*s) == (int)'p') {1408 1409 1410 1411 1412 1413 1414 1415 1416 1417 1418 1419 1420 1443 PyObject *result_as_float, *result; 1444 double x; 1445 long exp, top_exp, lsb, key_digit; 1446 char *s, *coeff_start, *s_store, *coeff_end, *exp_start, *s_end; 1447 int half_eps, digit, round_up, sign=1; 1448 Py_ssize_t length, ndigits, fdigits, i; 1449 1450 /* 1451 * For the sake of simplicity and correctness, we impose an artificial 1452 * limit on ndigits, the total number of hex digits in the coefficient 1453 * The limit is chosen to ensure that, writing exp for the exponent, 1454 * 1455 * (1) if exp > LONG_MAX/2 then the value of the hex string is 1456 * guaranteed to overflow (provided it's nonzero) 1457 * 1458 * (2) if exp < LONG_MIN/2 then the value of the hex string is 1459 * guaranteed to underflow to 0. 1460 * 1461 * (3) if LONG_MIN/2 <= exp <= LONG_MAX/2 then there's no danger of 1462 * overflow in the calculation of exp and top_exp below. 1463 * 1464 * More specifically, ndigits is assumed to satisfy the following 1465 * inequalities: 1466 * 1467 * 4*ndigits <= DBL_MIN_EXP - DBL_MANT_DIG - LONG_MIN/2 1468 * 4*ndigits <= LONG_MAX/2 + 1 - DBL_MAX_EXP 1469 * 1470 * If either of these inequalities is not satisfied, a ValueError is 1471 * raised. Otherwise, write x for the value of the hex string, and 1472 * assume x is nonzero. Then 1473 * 1474 * 2**(exp-4*ndigits) <= |x| < 2**(exp+4*ndigits). 1475 * 1476 * Now if exp > LONG_MAX/2 then: 1477 * 1478 * exp - 4*ndigits >= LONG_MAX/2 + 1 - (LONG_MAX/2 + 1 - DBL_MAX_EXP) 1479 * = DBL_MAX_EXP 1480 * 1481 * so |x| >= 2**DBL_MAX_EXP, which is too large to be stored in C 1482 * double, so overflows. If exp < LONG_MIN/2, then 1483 * 1484 * exp + 4*ndigits <= LONG_MIN/2 - 1 + ( 1485 * DBL_MIN_EXP - DBL_MANT_DIG - LONG_MIN/2) 1486 * = DBL_MIN_EXP - DBL_MANT_DIG - 1 1487 * 1488 * and so |x| < 2**(DBL_MIN_EXP-DBL_MANT_DIG-1), hence underflows to 0 1489 * when converted to a C double. 1490 * 1491 * It's easy to show that if LONG_MIN/2 <= exp <= LONG_MAX/2 then both 1492 * exp+4*ndigits and exp-4*ndigits are within the range of a long. 1493 */ 1494 1495 if (PyString_AsStringAndSize(arg, &s, &length)) 1496 return NULL; 1497 s_end = s + length; 1498 1499 /******************** 1500 * Parse the string * 1501 ********************/ 1502 1503 /* leading whitespace and optional sign */ 1504 while (Py_ISSPACE(*s)) 1505 s++; 1506 if (*s == '-') { 1507 s++; 1508 sign = -1; 1509 } 1510 else if (*s == '+') 1511 s++; 1512 1513 /* infinities and nans */ 1514 if (*s == 'i' || *s == 'I') { 1515 if (!case_insensitive_match(s+1, "nf")) 1516 goto parse_error; 1517 s += 3; 1518 x = Py_HUGE_VAL; 1519 if (case_insensitive_match(s, "inity")) 1520 s += 5; 1521 goto finished; 1522 } 1523 if (*s == 'n' || *s == 'N') { 1524 if (!case_insensitive_match(s+1, "an")) 1525 goto parse_error; 1526 s += 3; 1527 x = Py_NAN; 1528 goto finished; 1529 } 1530 1531 /* [0x] */ 1532 s_store = s; 1533 if (*s == '0') { 1534 s++; 1535 if (*s == 'x' || *s == 'X') 1536 s++; 1537 else 1538 s = s_store; 1539 } 1540 1541 /* coefficient: <integer> [. <fraction>] */ 1542 coeff_start = s; 1543 while (hex_from_char(*s) >= 0) 1544 s++; 1545 s_store = s; 1546 if (*s == '.') { 1547 s++; 1548 while (hex_from_char(*s) >= 0) 1549 s++; 1550 coeff_end = s-1; 1551 } 1552 else 1553 coeff_end = s; 1554 1555 /* ndigits = total # of hex digits; fdigits = # after point */ 1556 ndigits = coeff_end - coeff_start; 1557 fdigits = coeff_end - s_store; 1558 if (ndigits == 0) 1559 goto parse_error; 1560 if (ndigits > MIN(DBL_MIN_EXP - DBL_MANT_DIG - LONG_MIN/2, 1561 LONG_MAX/2 + 1 - DBL_MAX_EXP)/4) 1562 goto insane_length_error; 1563 1564 /* [p <exponent>] */ 1565 if (*s == 'p' || *s == 'P') { 1566 s++; 1567 exp_start = s; 1568 if (*s == '-' || *s == '+') 1569 s++; 1570 if (!('0' <= *s && *s <= '9')) 1571 goto parse_error; 1572 s++; 1573 while ('0' <= *s && *s <= '9') 1574 s++; 1575 exp = strtol(exp_start, NULL, 10); 1576 } 1577 else 1578 exp = 0; 1421 1579 1422 1580 /* for 0 <= j < ndigits, HEX_DIGIT(j) gives the jth most significant digit */ 1423 #define HEX_DIGIT(j) hex_from_char(*((j) < fdigits ? 1424 coeff_end-(j) :\1425 1426 1427 1428 1429 1430 1431 1432 1433 1434 1435 1436 1437 1438 1439 1440 1441 1442 1443 1444 1445 1446 1447 1448 1449 1450 1451 1452 1453 1454 1455 1456 1457 1458 1459 1460 1461 1462 1463 1464 1465 1466 1467 1468 1469 1470 1471 1472 1473 1474 1475 1476 1477 1478 1479 1480 1481 1482 1483 1484 1485 1486 1487 1488 1489 1490 1491 1492 1493 1494 1495 1496 1497 1498 1499 1500 1581 #define HEX_DIGIT(j) hex_from_char(*((j) < fdigits ? \ 1582 coeff_end-(j) : \ 1583 coeff_end-1-(j))) 1584 1585 /******************************************* 1586 * Compute rounded value of the hex string * 1587 *******************************************/ 1588 1589 /* Discard leading zeros, and catch extreme overflow and underflow */ 1590 while (ndigits > 0 && HEX_DIGIT(ndigits-1) == 0) 1591 ndigits--; 1592 if (ndigits == 0 || exp < LONG_MIN/2) { 1593 x = 0.0; 1594 goto finished; 1595 } 1596 if (exp > LONG_MAX/2) 1597 goto overflow_error; 1598 1599 /* Adjust exponent for fractional part. */ 1600 exp = exp - 4*((long)fdigits); 1601 1602 /* top_exp = 1 more than exponent of most sig. bit of coefficient */ 1603 top_exp = exp + 4*((long)ndigits - 1); 1604 for (digit = HEX_DIGIT(ndigits-1); digit != 0; digit /= 2) 1605 top_exp++; 1606 1607 /* catch almost all nonextreme cases of overflow and underflow here */ 1608 if (top_exp < DBL_MIN_EXP - DBL_MANT_DIG) { 1609 x = 0.0; 1610 goto finished; 1611 } 1612 if (top_exp > DBL_MAX_EXP) 1613 goto overflow_error; 1614 1615 /* lsb = exponent of least significant bit of the *rounded* value. 1616 This is top_exp - DBL_MANT_DIG unless result is subnormal. */ 1617 lsb = MAX(top_exp, (long)DBL_MIN_EXP) - DBL_MANT_DIG; 1618 1619 x = 0.0; 1620 if (exp >= lsb) { 1621 /* no rounding required */ 1622 for (i = ndigits-1; i >= 0; i--) 1623 x = 16.0*x + HEX_DIGIT(i); 1624 x = ldexp(x, (int)(exp)); 1625 goto finished; 1626 } 1627 /* rounding required. key_digit is the index of the hex digit 1628 containing the first bit to be rounded away. */ 1629 half_eps = 1 << (int)((lsb - exp - 1) % 4); 1630 key_digit = (lsb - exp - 1) / 4; 1631 for (i = ndigits-1; i > key_digit; i--) 1632 x = 16.0*x + HEX_DIGIT(i); 1633 digit = HEX_DIGIT(key_digit); 1634 x = 16.0*x + (double)(digit & (16-2*half_eps)); 1635 1636 /* round-half-even: round up if bit lsb-1 is 1 and at least one of 1637 bits lsb, lsb-2, lsb-3, lsb-4, ... is 1. */ 1638 if ((digit & half_eps) != 0) { 1639 round_up = 0; 1640 if ((digit & (3*half_eps-1)) != 0 || 1641 (half_eps == 8 && (HEX_DIGIT(key_digit+1) & 1) != 0)) 1642 round_up = 1; 1643 else 1644 for (i = key_digit-1; i >= 0; i--) 1645 if (HEX_DIGIT(i) != 0) { 1646 round_up = 1; 1647 break; 1648 } 1649 if (round_up == 1) { 1650 x += 2*half_eps; 1651 if (top_exp == DBL_MAX_EXP && 1652 x == ldexp((double)(2*half_eps), DBL_MANT_DIG)) 1653 /* overflow corner case: pre-rounded value < 1654 2**DBL_MAX_EXP; rounded=2**DBL_MAX_EXP. */ 1655 goto overflow_error; 1656 } 1657 } 1658 x = ldexp(x, (int)(exp+4*key_digit)); 1501 1659 1502 1660 finished: 1503 1504 while (*s && isspace(Py_CHARMASK(*s)))1505 1506 1507 1508 1509 1510 1511 1512 1513 1661 /* optional trailing whitespace leading to the end of the string */ 1662 while (Py_ISSPACE(*s)) 1663 s++; 1664 if (s != s_end) 1665 goto parse_error; 1666 result_as_float = Py_BuildValue("(d)", sign * x); 1667 if (result_as_float == NULL) 1668 return NULL; 1669 result = PyObject_CallObject(cls, result_as_float); 1670 Py_DECREF(result_as_float); 1671 return result; 1514 1672 1515 1673 overflow_error: 1516 1517 1518 1674 PyErr_SetString(PyExc_OverflowError, 1675 "hexadecimal value too large to represent as a float"); 1676 return NULL; 1519 1677 1520 1678 parse_error: 1521 1522 1523 1679 PyErr_SetString(PyExc_ValueError, 1680 "invalid hexadecimal floating-point string"); 1681 return NULL; 1524 1682 1525 1683 insane_length_error: 1526 1527 1528 1684 PyErr_SetString(PyExc_ValueError, 1685 "hexadecimal string too long to convert"); 1686 return NULL; 1529 1687 } 1530 1688 … … 1542 1700 float_as_integer_ratio(PyObject *v, PyObject *unused) 1543 1701 { 1544 1545 1546 1547 1548 1549 1550 1551 1552 1553 1554 1702 double self; 1703 double float_part; 1704 int exponent; 1705 int i; 1706 1707 PyObject *prev; 1708 PyObject *py_exponent = NULL; 1709 PyObject *numerator = NULL; 1710 PyObject *denominator = NULL; 1711 PyObject *result_pair = NULL; 1712 PyNumberMethods *long_methods = PyLong_Type.tp_as_number; 1555 1713 1556 1714 #define INPLACE_UPDATE(obj, call) \ 1557 1558 1559 1560 1561 1562 1563 1564 1565 1566 1567 1715 prev = obj; \ 1716 obj = call; \ 1717 Py_DECREF(prev); \ 1718 1719 CONVERT_TO_DOUBLE(v, self); 1720 1721 if (Py_IS_INFINITY(self)) { 1722 PyErr_SetString(PyExc_OverflowError, 1723 "Cannot pass infinity to float.as_integer_ratio."); 1724 return NULL; 1725 } 1568 1726 #ifdef Py_NAN 1569 1570 1571 1572 1573 1727 if (Py_IS_NAN(self)) { 1728 PyErr_SetString(PyExc_ValueError, 1729 "Cannot pass NaN to float.as_integer_ratio."); 1730 return NULL; 1731 } 1574 1732 #endif 1575 1733 1576 1577 float_part = frexp(self, &exponent);/* self == float_part * 2**exponent exactly */1578 1579 1580 1581 1582 1583 } 1584 1585 1586 1587 1588 1589 1590 1591 1592 1593 1594 1595 1596 1597 1598 1599 1600 1601 1602 1603 1604 1605 1606 1607 1608 1609 1610 1611 1612 1613 1614 1615 1734 PyFPE_START_PROTECT("as_integer_ratio", goto error); 1735 float_part = frexp(self, &exponent); /* self == float_part * 2**exponent exactly */ 1736 PyFPE_END_PROTECT(float_part); 1737 1738 for (i=0; i<300 && float_part != floor(float_part) ; i++) { 1739 float_part *= 2.0; 1740 exponent--; 1741 } 1742 /* self == float_part * 2**exponent exactly and float_part is integral. 1743 If FLT_RADIX != 2, the 300 steps may leave a tiny fractional part 1744 to be truncated by PyLong_FromDouble(). */ 1745 1746 numerator = PyLong_FromDouble(float_part); 1747 if (numerator == NULL) goto error; 1748 1749 /* fold in 2**exponent */ 1750 denominator = PyLong_FromLong(1); 1751 py_exponent = PyLong_FromLong(labs((long)exponent)); 1752 if (py_exponent == NULL) goto error; 1753 INPLACE_UPDATE(py_exponent, 1754 long_methods->nb_lshift(denominator, py_exponent)); 1755 if (py_exponent == NULL) goto error; 1756 if (exponent > 0) { 1757 INPLACE_UPDATE(numerator, 1758 long_methods->nb_multiply(numerator, py_exponent)); 1759 if (numerator == NULL) goto error; 1760 } 1761 else { 1762 Py_DECREF(denominator); 1763 denominator = py_exponent; 1764 py_exponent = NULL; 1765 } 1766 1767 /* Returns ints instead of longs where possible */ 1768 INPLACE_UPDATE(numerator, PyNumber_Int(numerator)); 1769 if (numerator == NULL) goto error; 1770 INPLACE_UPDATE(denominator, PyNumber_Int(denominator)); 1771 if (denominator == NULL) goto error; 1772 1773 result_pair = PyTuple_Pack(2, numerator, denominator); 1616 1774 1617 1775 #undef INPLACE_UPDATE 1618 1776 error: 1619 1620 1621 1622 1777 Py_XDECREF(py_exponent); 1778 Py_XDECREF(denominator); 1779 Py_XDECREF(numerator); 1780 return result_pair; 1623 1781 } 1624 1782 … … 1626 1784 "float.as_integer_ratio() -> (int, int)\n" 1627 1785 "\n" 1628 "Return sa pair of integers, whose ratio is exactly equal to the original\n"1786 "Return a pair of integers, whose ratio is exactly equal to the original\n" 1629 1787 "float and with a positive denominator.\n" 1630 "Raise sOverflowError on infinities and a ValueError on NaNs.\n"1788 "Raise OverflowError on infinities and a ValueError on NaNs.\n" 1631 1789 "\n" 1632 1790 ">>> (10.0).as_integer_ratio()\n" … … 1644 1802 float_new(PyTypeObject *type, PyObject *args, PyObject *kwds) 1645 1803 { 1646 1647 1648 1649 1650 1651 1652 1653 1654 1655 1656 1657 1804 PyObject *x = Py_False; /* Integer zero */ 1805 static char *kwlist[] = {"x", 0}; 1806 1807 if (type != &PyFloat_Type) 1808 return float_subtype_new(type, args, kwds); /* Wimp out */ 1809 if (!PyArg_ParseTupleAndKeywords(args, kwds, "|O:float", kwlist, &x)) 1810 return NULL; 1811 /* If it's a string, but not a string subclass, use 1812 PyFloat_FromString. */ 1813 if (PyString_CheckExact(x)) 1814 return PyFloat_FromString(x, NULL); 1815 return PyNumber_Float(x); 1658 1816 } 1659 1817 … … 1666 1824 float_subtype_new(PyTypeObject *type, PyObject *args, PyObject *kwds) 1667 1825 { 1668 1669 1670 1671 1672 1673 1674 1675 1676 1677 1678 1679 1680 1681 1682 1826 PyObject *tmp, *newobj; 1827 1828 assert(PyType_IsSubtype(type, &PyFloat_Type)); 1829 tmp = float_new(&PyFloat_Type, args, kwds); 1830 if (tmp == NULL) 1831 return NULL; 1832 assert(PyFloat_CheckExact(tmp)); 1833 newobj = type->tp_alloc(type, 0); 1834 if (newobj == NULL) { 1835 Py_DECREF(tmp); 1836 return NULL; 1837 } 1838 ((PyFloatObject *)newobj)->ob_fval = ((PyFloatObject *)tmp)->ob_fval; 1839 Py_DECREF(tmp); 1840 return newobj; 1683 1841 } 1684 1842 … … 1686 1844 float_getnewargs(PyFloatObject *v) 1687 1845 { 1688 1846 return Py_BuildValue("(d)", v->ob_fval); 1689 1847 } 1690 1848 … … 1692 1850 1693 1851 typedef enum { 1694 1852 unknown_format, ieee_big_endian_format, ieee_little_endian_format 1695 1853 } float_format_type; 1696 1854 … … 1701 1859 float_getformat(PyTypeObject *v, PyObject* arg) 1702 1860 { 1703 1704 1705 1706 1707 1708 1709 1710 1711 1712 1713 1714 1715 1716 1717 1718 1719 1720 1721 1722 1723 1724 1725 1726 1727 1728 1729 1730 1731 1732 1733 1734 1735 1736 1861 char* s; 1862 float_format_type r; 1863 1864 if (!PyString_Check(arg)) { 1865 PyErr_Format(PyExc_TypeError, 1866 "__getformat__() argument must be string, not %.500s", 1867 Py_TYPE(arg)->tp_name); 1868 return NULL; 1869 } 1870 s = PyString_AS_STRING(arg); 1871 if (strcmp(s, "double") == 0) { 1872 r = double_format; 1873 } 1874 else if (strcmp(s, "float") == 0) { 1875 r = float_format; 1876 } 1877 else { 1878 PyErr_SetString(PyExc_ValueError, 1879 "__getformat__() argument 1 must be " 1880 "'double' or 'float'"); 1881 return NULL; 1882 } 1883 1884 switch (r) { 1885 case unknown_format: 1886 return PyString_FromString("unknown"); 1887 case ieee_little_endian_format: 1888 return PyString_FromString("IEEE, little-endian"); 1889 case ieee_big_endian_format: 1890 return PyString_FromString("IEEE, big-endian"); 1891 default: 1892 Py_FatalError("insane float_format or double_format"); 1893 return NULL; 1894 } 1737 1895 } 1738 1896 … … 1750 1908 float_setformat(PyTypeObject *v, PyObject* args) 1751 1909 { 1752 1753 1754 1755 1756 1757 1758 1759 1760 1761 1762 1763 1764 1765 1766 1767 1768 1769 1770 1771 1772 1773 1774 1775 1776 1777 1778 1779 1780 1781 1782 1783 1784 1785 1786 1787 1788 1789 1790 1791 1792 1793 1794 1795 1796 1797 1798 1799 1800 1801 1802 1910 char* typestr; 1911 char* format; 1912 float_format_type f; 1913 float_format_type detected; 1914 float_format_type *p; 1915 1916 if (!PyArg_ParseTuple(args, "ss:__setformat__", &typestr, &format)) 1917 return NULL; 1918 1919 if (strcmp(typestr, "double") == 0) { 1920 p = &double_format; 1921 detected = detected_double_format; 1922 } 1923 else if (strcmp(typestr, "float") == 0) { 1924 p = &float_format; 1925 detected = detected_float_format; 1926 } 1927 else { 1928 PyErr_SetString(PyExc_ValueError, 1929 "__setformat__() argument 1 must " 1930 "be 'double' or 'float'"); 1931 return NULL; 1932 } 1933 1934 if (strcmp(format, "unknown") == 0) { 1935 f = unknown_format; 1936 } 1937 else if (strcmp(format, "IEEE, little-endian") == 0) { 1938 f = ieee_little_endian_format; 1939 } 1940 else if (strcmp(format, "IEEE, big-endian") == 0) { 1941 f = ieee_big_endian_format; 1942 } 1943 else { 1944 PyErr_SetString(PyExc_ValueError, 1945 "__setformat__() argument 2 must be " 1946 "'unknown', 'IEEE, little-endian' or " 1947 "'IEEE, big-endian'"); 1948 return NULL; 1949 1950 } 1951 1952 if (f != unknown_format && f != detected) { 1953 PyErr_Format(PyExc_ValueError, 1954 "can only set %s format to 'unknown' or the " 1955 "detected platform value", typestr); 1956 return NULL; 1957 } 1958 1959 *p = f; 1960 Py_RETURN_NONE; 1803 1961 } 1804 1962 … … 1813 1971 "one of the latter two if it appears to match the underlying C reality.\n" 1814 1972 "\n" 1815 "Override sthe automatic determination of C-level floating point type.\n"1973 "Override the automatic determination of C-level floating point type.\n" 1816 1974 "This affects how floats are converted to and from binary strings."); 1817 1975 … … 1819 1977 float_getzero(PyObject *v, void *closure) 1820 1978 { 1821 1979 return PyFloat_FromDouble(0.0); 1822 1980 } 1823 1981 … … 1825 1983 float__format__(PyObject *self, PyObject *args) 1826 1984 { 1827 1828 1829 1830 1831 1832 1833 1834 1835 1836 1837 1838 1839 1840 1841 1842 1843 1844 1845 1846 1847 1848 1849 1850 1851 1985 PyObject *format_spec; 1986 1987 if (!PyArg_ParseTuple(args, "O:__format__", &format_spec)) 1988 return NULL; 1989 if (PyBytes_Check(format_spec)) 1990 return _PyFloat_FormatAdvanced(self, 1991 PyBytes_AS_STRING(format_spec), 1992 PyBytes_GET_SIZE(format_spec)); 1993 if (PyUnicode_Check(format_spec)) { 1994 /* Convert format_spec to a str */ 1995 PyObject *result; 1996 PyObject *str_spec = PyObject_Str(format_spec); 1997 1998 if (str_spec == NULL) 1999 return NULL; 2000 2001 result = _PyFloat_FormatAdvanced(self, 2002 PyBytes_AS_STRING(str_spec), 2003 PyBytes_GET_SIZE(str_spec)); 2004 2005 Py_DECREF(str_spec); 2006 return result; 2007 } 2008 PyErr_SetString(PyExc_TypeError, "__format__ requires str or unicode"); 2009 return NULL; 1852 2010 } 1853 2011 … … 1859 2017 1860 2018 static PyMethodDef float_methods[] = { 1861 {"conjugate", (PyCFunction)float_float,METH_NOARGS,1862 "Returnsself, the complex conjugate of any float."},1863 {"__trunc__",(PyCFunction)float_trunc, METH_NOARGS,1864 "Returnsthe Integral closest to x between 0 and x."},1865 1866 1867 1868 1869 1870 1871 {"is_integer", (PyCFunction)float_is_integer,METH_NOARGS,1872 "ReturnsTrue if the float is an integer."},2019 {"conjugate", (PyCFunction)float_float, METH_NOARGS, 2020 "Return self, the complex conjugate of any float."}, 2021 {"__trunc__", (PyCFunction)float_trunc, METH_NOARGS, 2022 "Return the Integral closest to x between 0 and x."}, 2023 {"as_integer_ratio", (PyCFunction)float_as_integer_ratio, METH_NOARGS, 2024 float_as_integer_ratio_doc}, 2025 {"fromhex", (PyCFunction)float_fromhex, 2026 METH_O|METH_CLASS, float_fromhex_doc}, 2027 {"hex", (PyCFunction)float_hex, 2028 METH_NOARGS, float_hex_doc}, 2029 {"is_integer", (PyCFunction)float_is_integer, METH_NOARGS, 2030 "Return True if the float is an integer."}, 1873 2031 #if 0 1874 {"is_inf", (PyCFunction)float_is_inf,METH_NOARGS,1875 "ReturnsTrue if the float is positive or negative infinite."},1876 {"is_finite", (PyCFunction)float_is_finite,METH_NOARGS,1877 "ReturnsTrue if the float is finite, neither infinite nor NaN."},1878 {"is_nan", (PyCFunction)float_is_nan,METH_NOARGS,1879 "ReturnsTrue if the float is not a number (NaN)."},2032 {"is_inf", (PyCFunction)float_is_inf, METH_NOARGS, 2033 "Return True if the float is positive or negative infinite."}, 2034 {"is_finite", (PyCFunction)float_is_finite, METH_NOARGS, 2035 "Return True if the float is finite, neither infinite nor NaN."}, 2036 {"is_nan", (PyCFunction)float_is_nan, METH_NOARGS, 2037 "Return True if the float is not a number (NaN)."}, 1880 2038 #endif 1881 {"__getnewargs__", (PyCFunction)float_getnewargs,METH_NOARGS},1882 {"__getformat__", (PyCFunction)float_getformat, 1883 METH_O|METH_CLASS,float_getformat_doc},1884 {"__setformat__", (PyCFunction)float_setformat, 1885 METH_VARARGS|METH_CLASS,float_setformat_doc},1886 1887 1888 {NULL, NULL}/* sentinel */2039 {"__getnewargs__", (PyCFunction)float_getnewargs, METH_NOARGS}, 2040 {"__getformat__", (PyCFunction)float_getformat, 2041 METH_O|METH_CLASS, float_getformat_doc}, 2042 {"__setformat__", (PyCFunction)float_setformat, 2043 METH_VARARGS|METH_CLASS, float_setformat_doc}, 2044 {"__format__", (PyCFunction)float__format__, 2045 METH_VARARGS, float__format__doc}, 2046 {NULL, NULL} /* sentinel */ 1889 2047 }; 1890 2048 1891 2049 static PyGetSetDef float_getset[] = { 1892 {"real", 2050 {"real", 1893 2051 (getter)float_float, (setter)NULL, 1894 2052 "the real part of a complex number", 1895 2053 NULL}, 1896 {"imag", 2054 {"imag", 1897 2055 (getter)float_getzero, (setter)NULL, 1898 2056 "the imaginary part of a complex number", … … 1908 2066 1909 2067 static PyNumberMethods float_as_number = { 1910 float_add,/*nb_add*/1911 float_sub,/*nb_subtract*/1912 float_mul,/*nb_multiply*/1913 1914 float_rem,/*nb_remainder*/1915 float_divmod,/*nb_divmod*/1916 float_pow,/*nb_power*/1917 1918 1919 1920 1921 0,/*nb_invert*/1922 0,/*nb_lshift*/1923 0,/*nb_rshift*/1924 0,/*nb_and*/1925 0,/*nb_xor*/1926 0,/*nb_or*/1927 float_coerce,/*nb_coerce*/1928 float_trunc,/*nb_int*/1929 float_long,/*nb_long*/1930 float_float,/*nb_float*/1931 0,/* nb_oct */1932 0,/* nb_hex */1933 0,/* nb_inplace_add */1934 0,/* nb_inplace_subtract */1935 0,/* nb_inplace_multiply */1936 0,/* nb_inplace_divide */1937 0,/* nb_inplace_remainder */1938 0,/* nb_inplace_power */1939 0,/* nb_inplace_lshift */1940 0,/* nb_inplace_rshift */1941 0,/* nb_inplace_and */1942 0,/* nb_inplace_xor */1943 0,/* nb_inplace_or */1944 1945 float_div,/* nb_true_divide */1946 0,/* nb_inplace_floor_divide */1947 0,/* nb_inplace_true_divide */2068 float_add, /*nb_add*/ 2069 float_sub, /*nb_subtract*/ 2070 float_mul, /*nb_multiply*/ 2071 float_classic_div, /*nb_divide*/ 2072 float_rem, /*nb_remainder*/ 2073 float_divmod, /*nb_divmod*/ 2074 float_pow, /*nb_power*/ 2075 (unaryfunc)float_neg, /*nb_negative*/ 2076 (unaryfunc)float_float, /*nb_positive*/ 2077 (unaryfunc)float_abs, /*nb_absolute*/ 2078 (inquiry)float_nonzero, /*nb_nonzero*/ 2079 0, /*nb_invert*/ 2080 0, /*nb_lshift*/ 2081 0, /*nb_rshift*/ 2082 0, /*nb_and*/ 2083 0, /*nb_xor*/ 2084 0, /*nb_or*/ 2085 float_coerce, /*nb_coerce*/ 2086 float_trunc, /*nb_int*/ 2087 float_long, /*nb_long*/ 2088 float_float, /*nb_float*/ 2089 0, /* nb_oct */ 2090 0, /* nb_hex */ 2091 0, /* nb_inplace_add */ 2092 0, /* nb_inplace_subtract */ 2093 0, /* nb_inplace_multiply */ 2094 0, /* nb_inplace_divide */ 2095 0, /* nb_inplace_remainder */ 2096 0, /* nb_inplace_power */ 2097 0, /* nb_inplace_lshift */ 2098 0, /* nb_inplace_rshift */ 2099 0, /* nb_inplace_and */ 2100 0, /* nb_inplace_xor */ 2101 0, /* nb_inplace_or */ 2102 float_floor_div, /* nb_floor_divide */ 2103 float_div, /* nb_true_divide */ 2104 0, /* nb_inplace_floor_divide */ 2105 0, /* nb_inplace_true_divide */ 1948 2106 }; 1949 2107 1950 2108 PyTypeObject PyFloat_Type = { 1951 1952 1953 1954 1955 (destructor)float_dealloc,/* tp_dealloc */1956 (printfunc)float_print,/* tp_print */1957 0,/* tp_getattr */1958 0,/* tp_setattr */1959 0,/* tp_compare */1960 (reprfunc)float_repr,/* tp_repr */1961 &float_as_number,/* tp_as_number */1962 0,/* tp_as_sequence */1963 0,/* tp_as_mapping */1964 (hashfunc)float_hash,/* tp_hash */1965 0,/* tp_call */1966 (reprfunc)float_str,/* tp_str */1967 PyObject_GenericGetAttr,/* tp_getattro */1968 0,/* tp_setattro */1969 0,/* tp_as_buffer */1970 1971 Py_TPFLAGS_BASETYPE,/* tp_flags */1972 float_doc,/* tp_doc */1973 0,/* tp_traverse */1974 0,/* tp_clear */1975 float_richcompare,/* tp_richcompare */1976 0,/* tp_weaklistoffset */1977 0,/* tp_iter */1978 0,/* tp_iternext */1979 float_methods,/* tp_methods */1980 0,/* tp_members */1981 float_getset,/* tp_getset */1982 0,/* tp_base */1983 0,/* tp_dict */1984 0,/* tp_descr_get */1985 0,/* tp_descr_set */1986 0,/* tp_dictoffset */1987 0,/* tp_init */1988 0,/* tp_alloc */1989 float_new,/* tp_new */2109 PyVarObject_HEAD_INIT(&PyType_Type, 0) 2110 "float", 2111 sizeof(PyFloatObject), 2112 0, 2113 (destructor)float_dealloc, /* tp_dealloc */ 2114 (printfunc)float_print, /* tp_print */ 2115 0, /* tp_getattr */ 2116 0, /* tp_setattr */ 2117 0, /* tp_compare */ 2118 (reprfunc)float_repr, /* tp_repr */ 2119 &float_as_number, /* tp_as_number */ 2120 0, /* tp_as_sequence */ 2121 0, /* tp_as_mapping */ 2122 (hashfunc)float_hash, /* tp_hash */ 2123 0, /* tp_call */ 2124 (reprfunc)float_str, /* tp_str */ 2125 PyObject_GenericGetAttr, /* tp_getattro */ 2126 0, /* tp_setattro */ 2127 0, /* tp_as_buffer */ 2128 Py_TPFLAGS_DEFAULT | Py_TPFLAGS_CHECKTYPES | 2129 Py_TPFLAGS_BASETYPE, /* tp_flags */ 2130 float_doc, /* tp_doc */ 2131 0, /* tp_traverse */ 2132 0, /* tp_clear */ 2133 float_richcompare, /* tp_richcompare */ 2134 0, /* tp_weaklistoffset */ 2135 0, /* tp_iter */ 2136 0, /* tp_iternext */ 2137 float_methods, /* tp_methods */ 2138 0, /* tp_members */ 2139 float_getset, /* tp_getset */ 2140 0, /* tp_base */ 2141 0, /* tp_dict */ 2142 0, /* tp_descr_get */ 2143 0, /* tp_descr_set */ 2144 0, /* tp_dictoffset */ 2145 0, /* tp_init */ 2146 0, /* tp_alloc */ 2147 float_new, /* tp_new */ 1990 2148 }; 1991 2149 … … 1993 2151 _PyFloat_Init(void) 1994 2152 { 1995 1996 1997 1998 1999 2000 2001 2002 2003 2004 2005 2006 2007 2008 2153 /* We attempt to determine if this machine is using IEEE 2154 floating point formats by peering at the bits of some 2155 carefully chosen values. If it looks like we are on an 2156 IEEE platform, the float packing/unpacking routines can 2157 just copy bits, if not they resort to arithmetic & shifts 2158 and masks. The shifts & masks approach works on all finite 2159 values, but what happens to infinities, NaNs and signed 2160 zeroes on packing is an accident, and attempting to unpack 2161 a NaN or an infinity will raise an exception. 2162 2163 Note that if we're on some whacked-out platform which uses 2164 IEEE formats but isn't strictly little-endian or big- 2165 endian, we will fall back to the portable shifts & masks 2166 method. */ 2009 2167 2010 2168 #if SIZEOF_DOUBLE == 8 2011 2012 2013 2014 2015 2016 2017 else 2018 2019 2169 { 2170 double x = 9006104071832581.0; 2171 if (memcmp(&x, "\x43\x3f\xff\x01\x02\x03\x04\x05", 8) == 0) 2172 detected_double_format = ieee_big_endian_format; 2173 else if (memcmp(&x, "\x05\x04\x03\x02\x01\xff\x3f\x43", 8) == 0) 2174 detected_double_format = ieee_little_endian_format; 2175 else 2176 detected_double_format = unknown_format; 2177 } 2020 2178 #else 2021 2179 detected_double_format = unknown_format; 2022 2180 #endif 2023 2181 2024 2182 #if SIZEOF_FLOAT == 4 2025 2026 2027 2028 2029 2030 2031 else 2032 2033 2183 { 2184 float y = 16711938.0; 2185 if (memcmp(&y, "\x4b\x7f\x01\x02", 4) == 0) 2186 detected_float_format = ieee_big_endian_format; 2187 else if (memcmp(&y, "\x02\x01\x7f\x4b", 4) == 0) 2188 detected_float_format = ieee_little_endian_format; 2189 else 2190 detected_float_format = unknown_format; 2191 } 2034 2192 #else 2035 2193 detected_float_format = unknown_format; 2036 2194 #endif 2037 2195 2038 2039 2040 2041 2042 2043 2196 double_format = detected_double_format; 2197 float_format = detected_float_format; 2198 2199 /* Init float info */ 2200 if (FloatInfoType.tp_name == 0) 2201 PyStructSequence_InitType(&FloatInfoType, &floatinfo_desc); 2044 2202 } 2045 2203 … … 2047 2205 PyFloat_ClearFreeList(void) 2048 2206 { 2049 2050 2051 2052 int u;/* remaining unfreed ints per block */2053 2054 2055 2056 2057 2058 2059 2060 2061 2062 2063 2064 2065 2066 2067 2068 2069 2070 2071 2072 2073 2074 2075 2076 2077 2078 2079 2080 2081 2082 2083 2084 2085 2086 2087 2207 PyFloatObject *p; 2208 PyFloatBlock *list, *next; 2209 int i; 2210 int u; /* remaining unfreed ints per block */ 2211 int freelist_size = 0; 2212 2213 list = block_list; 2214 block_list = NULL; 2215 free_list = NULL; 2216 while (list != NULL) { 2217 u = 0; 2218 for (i = 0, p = &list->objects[0]; 2219 i < N_FLOATOBJECTS; 2220 i++, p++) { 2221 if (PyFloat_CheckExact(p) && Py_REFCNT(p) != 0) 2222 u++; 2223 } 2224 next = list->next; 2225 if (u) { 2226 list->next = block_list; 2227 block_list = list; 2228 for (i = 0, p = &list->objects[0]; 2229 i < N_FLOATOBJECTS; 2230 i++, p++) { 2231 if (!PyFloat_CheckExact(p) || 2232 Py_REFCNT(p) == 0) { 2233 Py_TYPE(p) = (struct _typeobject *) 2234 free_list; 2235 free_list = p; 2236 } 2237 } 2238 } 2239 else { 2240 PyMem_FREE(list); 2241 } 2242 freelist_size += u; 2243 list = next; 2244 } 2245 return freelist_size; 2088 2246 } 2089 2247 … … 2091 2249 PyFloat_Fini(void) 2092 2250 { 2093 PyFloatObject *p; 2094 PyFloatBlock *list; 2095 int i; 2096 int u; /* total unfreed floats per block */ 2097 2098 u = PyFloat_ClearFreeList(); 2099 2100 if (!Py_VerboseFlag) 2101 return; 2102 fprintf(stderr, "# cleanup floats"); 2103 if (!u) { 2104 fprintf(stderr, "\n"); 2105 } 2106 else { 2107 fprintf(stderr, 2108 ": %d unfreed float%s\n", 2109 u, u == 1 ? "" : "s"); 2110 } 2111 if (Py_VerboseFlag > 1) { 2112 list = block_list; 2113 while (list != NULL) { 2114 for (i = 0, p = &list->objects[0]; 2115 i < N_FLOATOBJECTS; 2116 i++, p++) { 2117 if (PyFloat_CheckExact(p) && 2118 Py_REFCNT(p) != 0) { 2119 char buf[100]; 2120 PyFloat_AsString(buf, p); 2121 /* XXX(twouters) cast refcount to 2122 long until %zd is universally 2123 available 2124 */ 2125 fprintf(stderr, 2126 "# <float at %p, refcnt=%ld, val=%s>\n", 2127 p, (long)Py_REFCNT(p), buf); 2128 } 2129 } 2130 list = list->next; 2131 } 2132 } 2251 PyFloatObject *p; 2252 PyFloatBlock *list; 2253 int i; 2254 int u; /* total unfreed floats per block */ 2255 2256 u = PyFloat_ClearFreeList(); 2257 2258 if (!Py_VerboseFlag) 2259 return; 2260 fprintf(stderr, "# cleanup floats"); 2261 if (!u) { 2262 fprintf(stderr, "\n"); 2263 } 2264 else { 2265 fprintf(stderr, 2266 ": %d unfreed float%s\n", 2267 u, u == 1 ? "" : "s"); 2268 } 2269 if (Py_VerboseFlag > 1) { 2270 list = block_list; 2271 while (list != NULL) { 2272 for (i = 0, p = &list->objects[0]; 2273 i < N_FLOATOBJECTS; 2274 i++, p++) { 2275 if (PyFloat_CheckExact(p) && 2276 Py_REFCNT(p) != 0) { 2277 char *buf = PyOS_double_to_string( 2278 PyFloat_AS_DOUBLE(p), 'r', 2279 0, 0, NULL); 2280 if (buf) { 2281 /* XXX(twouters) cast 2282 refcount to long 2283 until %zd is 2284 universally 2285 available 2286 */ 2287 fprintf(stderr, 2288 "# <float at %p, refcnt=%ld, val=%s>\n", 2289 p, (long)Py_REFCNT(p), buf); 2290 PyMem_Free(buf); 2291 } 2292 } 2293 } 2294 list = list->next; 2295 } 2296 } 2133 2297 } 2134 2298 … … 2139 2303 _PyFloat_Pack4(double x, unsigned char *p, int le) 2140 2304 { 2141 2142 2143 2144 2145 2146 2147 2148 2149 2150 2151 2152 2153 2154 2155 2156 2157 2158 2159 2160 2161 2162 2163 2164 2165 2166 2167 2168 2169 2170 2171 2172 2173 2174 2175 2176 2177 2178 2179 2180 2181 2182 2183 2184 2185 2186 2187 2188 2189 2190 2191 2192 2193 2194 2195 2196 2197 2198 2199 2200 2201 2202 2203 2204 2205 2206 2207 2208 2209 2210 2211 2212 2213 2214 2215 2216 2217 2218 2219 2220 2221 2222 2223 2224 2225 2226 2227 2228 2229 2230 2231 2232 2233 2234 2235 2236 2305 if (float_format == unknown_format) { 2306 unsigned char sign; 2307 int e; 2308 double f; 2309 unsigned int fbits; 2310 int incr = 1; 2311 2312 if (le) { 2313 p += 3; 2314 incr = -1; 2315 } 2316 2317 if (x < 0) { 2318 sign = 1; 2319 x = -x; 2320 } 2321 else 2322 sign = 0; 2323 2324 f = frexp(x, &e); 2325 2326 /* Normalize f to be in the range [1.0, 2.0) */ 2327 if (0.5 <= f && f < 1.0) { 2328 f *= 2.0; 2329 e--; 2330 } 2331 else if (f == 0.0) 2332 e = 0; 2333 else { 2334 PyErr_SetString(PyExc_SystemError, 2335 "frexp() result out of range"); 2336 return -1; 2337 } 2338 2339 if (e >= 128) 2340 goto Overflow; 2341 else if (e < -126) { 2342 /* Gradual underflow */ 2343 f = ldexp(f, 126 + e); 2344 e = 0; 2345 } 2346 else if (!(e == 0 && f == 0.0)) { 2347 e += 127; 2348 f -= 1.0; /* Get rid of leading 1 */ 2349 } 2350 2351 f *= 8388608.0; /* 2**23 */ 2352 fbits = (unsigned int)(f + 0.5); /* Round */ 2353 assert(fbits <= 8388608); 2354 if (fbits >> 23) { 2355 /* The carry propagated out of a string of 23 1 bits. */ 2356 fbits = 0; 2357 ++e; 2358 if (e >= 255) 2359 goto Overflow; 2360 } 2361 2362 /* First byte */ 2363 *p = (sign << 7) | (e >> 1); 2364 p += incr; 2365 2366 /* Second byte */ 2367 *p = (char) (((e & 1) << 7) | (fbits >> 16)); 2368 p += incr; 2369 2370 /* Third byte */ 2371 *p = (fbits >> 8) & 0xFF; 2372 p += incr; 2373 2374 /* Fourth byte */ 2375 *p = fbits & 0xFF; 2376 2377 /* Done */ 2378 return 0; 2379 2380 } 2381 else { 2382 float y = (float)x; 2383 const char *s = (char*)&y; 2384 int i, incr = 1; 2385 2386 if (Py_IS_INFINITY(y) && !Py_IS_INFINITY(x)) 2387 goto Overflow; 2388 2389 if ((float_format == ieee_little_endian_format && !le) 2390 || (float_format == ieee_big_endian_format && le)) { 2391 p += 3; 2392 incr = -1; 2393 } 2394 2395 for (i = 0; i < 4; i++) { 2396 *p = *s++; 2397 p += incr; 2398 } 2399 return 0; 2400 } 2237 2401 Overflow: 2238 2239 2240 2402 PyErr_SetString(PyExc_OverflowError, 2403 "float too large to pack with f format"); 2404 return -1; 2241 2405 } 2242 2406 … … 2244 2408 _PyFloat_Pack8(double x, unsigned char *p, int le) 2245 2409 { 2246 2247 2248 2249 2250 2251 2252 2253 2254 2255 2256 2257 2258 2259 2260 2261 2262 2263 2264 2265 2266 2267 2268 2269 2270 2271 2272 2273 2274 2275 2276 2277 2278 2279 2280 2281 2282 2283 2284 2285 2286 2287 2288 2289 2290 2291 2292 2293 2294 2295 2296 2297 2298 2299 2300 2301 2302 2303 2304 2305 2306 2307 2308 2309 2310 2311 2312 2313 2314 2315 2316 2317 2318 2319 2320 2321 2322 2323 2324 2325 2326 2327 2328 2329 2330 2331 2332 2333 2334 2335 2336 2337 2338 2339 2340 2341 2342 2343 2344 p += incr; 2345 2346 2347 2348 2349 2350 2351 2352 2353 2354 2355 2356 2357 2358 2359 2360 2361 2362 2363 2364 2365 2366 2367 2368 2369 2410 if (double_format == unknown_format) { 2411 unsigned char sign; 2412 int e; 2413 double f; 2414 unsigned int fhi, flo; 2415 int incr = 1; 2416 2417 if (le) { 2418 p += 7; 2419 incr = -1; 2420 } 2421 2422 if (x < 0) { 2423 sign = 1; 2424 x = -x; 2425 } 2426 else 2427 sign = 0; 2428 2429 f = frexp(x, &e); 2430 2431 /* Normalize f to be in the range [1.0, 2.0) */ 2432 if (0.5 <= f && f < 1.0) { 2433 f *= 2.0; 2434 e--; 2435 } 2436 else if (f == 0.0) 2437 e = 0; 2438 else { 2439 PyErr_SetString(PyExc_SystemError, 2440 "frexp() result out of range"); 2441 return -1; 2442 } 2443 2444 if (e >= 1024) 2445 goto Overflow; 2446 else if (e < -1022) { 2447 /* Gradual underflow */ 2448 f = ldexp(f, 1022 + e); 2449 e = 0; 2450 } 2451 else if (!(e == 0 && f == 0.0)) { 2452 e += 1023; 2453 f -= 1.0; /* Get rid of leading 1 */ 2454 } 2455 2456 /* fhi receives the high 28 bits; flo the low 24 bits (== 52 bits) */ 2457 f *= 268435456.0; /* 2**28 */ 2458 fhi = (unsigned int)f; /* Truncate */ 2459 assert(fhi < 268435456); 2460 2461 f -= (double)fhi; 2462 f *= 16777216.0; /* 2**24 */ 2463 flo = (unsigned int)(f + 0.5); /* Round */ 2464 assert(flo <= 16777216); 2465 if (flo >> 24) { 2466 /* The carry propagated out of a string of 24 1 bits. */ 2467 flo = 0; 2468 ++fhi; 2469 if (fhi >> 28) { 2470 /* And it also progagated out of the next 28 bits. */ 2471 fhi = 0; 2472 ++e; 2473 if (e >= 2047) 2474 goto Overflow; 2475 } 2476 } 2477 2478 /* First byte */ 2479 *p = (sign << 7) | (e >> 4); 2480 p += incr; 2481 2482 /* Second byte */ 2483 *p = (unsigned char) (((e & 0xF) << 4) | (fhi >> 24)); 2484 p += incr; 2485 2486 /* Third byte */ 2487 *p = (fhi >> 16) & 0xFF; 2488 p += incr; 2489 2490 /* Fourth byte */ 2491 *p = (fhi >> 8) & 0xFF; 2492 p += incr; 2493 2494 /* Fifth byte */ 2495 *p = fhi & 0xFF; 2496 p += incr; 2497 2498 /* Sixth byte */ 2499 *p = (flo >> 16) & 0xFF; 2500 p += incr; 2501 2502 /* Seventh byte */ 2503 *p = (flo >> 8) & 0xFF; 2504 p += incr; 2505 2506 /* Eighth byte */ 2507 *p = flo & 0xFF; 2508 /* p += incr; Unneeded (for now) */ 2509 2510 /* Done */ 2511 return 0; 2512 2513 Overflow: 2514 PyErr_SetString(PyExc_OverflowError, 2515 "float too large to pack with d format"); 2516 return -1; 2517 } 2518 else { 2519 const char *s = (char*)&x; 2520 int i, incr = 1; 2521 2522 if ((double_format == ieee_little_endian_format && !le) 2523 || (double_format == ieee_big_endian_format && le)) { 2524 p += 7; 2525 incr = -1; 2526 } 2527 2528 for (i = 0; i < 8; i++) { 2529 *p = *s++; 2530 p += incr; 2531 } 2532 return 0; 2533 } 2370 2534 } 2371 2535 … … 2373 2537 _PyFloat_Unpack4(const unsigned char *p, int le) 2374 2538 { 2375 2376 2377 2378 2379 2380 2381 2382 2383 2384 2385 2386 2387 2388 2389 2390 2391 2392 2393 2394 2395 2396 2397 2398 2399 2400 2401 2402 2403 2404 2405 2406 2407 2408 2409 2410 2411 2412 2413 2414 2415 2416 2417 2418 2419 2420 2421 2422 2423 2424 2425 2426 2427 2428 2429 2430 2431 2432 2433 2434 2435 2436 2437 2438 2439 2440 2441 2442 2443 2444 2445 2446 2447 } 2539 if (float_format == unknown_format) { 2540 unsigned char sign; 2541 int e; 2542 unsigned int f; 2543 double x; 2544 int incr = 1; 2545 2546 if (le) { 2547 p += 3; 2548 incr = -1; 2549 } 2550 2551 /* First byte */ 2552 sign = (*p >> 7) & 1; 2553 e = (*p & 0x7F) << 1; 2554 p += incr; 2555 2556 /* Second byte */ 2557 e |= (*p >> 7) & 1; 2558 f = (*p & 0x7F) << 16; 2559 p += incr; 2560 2561 if (e == 255) { 2562 PyErr_SetString( 2563 PyExc_ValueError, 2564 "can't unpack IEEE 754 special value " 2565 "on non-IEEE platform"); 2566 return -1; 2567 } 2568 2569 /* Third byte */ 2570 f |= *p << 8; 2571 p += incr; 2572 2573 /* Fourth byte */ 2574 f |= *p; 2575 2576 x = (double)f / 8388608.0; 2577 2578 /* XXX This sadly ignores Inf/NaN issues */ 2579 if (e == 0) 2580 e = -126; 2581 else { 2582 x += 1.0; 2583 e -= 127; 2584 } 2585 x = ldexp(x, e); 2586 2587 if (sign) 2588 x = -x; 2589 2590 return x; 2591 } 2592 else { 2593 float x; 2594 2595 if ((float_format == ieee_little_endian_format && !le) 2596 || (float_format == ieee_big_endian_format && le)) { 2597 char buf[4]; 2598 char *d = &buf[3]; 2599 int i; 2600 2601 for (i = 0; i < 4; i++) { 2602 *d-- = *p++; 2603 } 2604 memcpy(&x, buf, 4); 2605 } 2606 else { 2607 memcpy(&x, p, 4); 2608 } 2609 2610 return x; 2611 } 2448 2612 } 2449 2613 … … 2451 2615 _PyFloat_Unpack8(const unsigned char *p, int le) 2452 2616 { 2453 2454 2455 2456 2457 2458 2459 2460 2461 2462 2463 2464 2465 2466 2467 2468 2469 2470 2471 2472 2473 2474 2475 2476 2477 2478 2479 2480 2481 2482 2483 2484 2485 2486 2487 2488 2489 2490 2491 2492 2493 2494 2495 2496 2497 2498 2499 2500 2501 2502 2503 2504 2505 2506 2507 2508 2509 2510 2511 2512 2513 2514 2515 2516 2517 2518 2519 2520 2521 2522 2523 2524 2525 2526 2527 2528 2529 2530 2531 2532 2533 2534 2535 2536 2537 2538 2539 2540 2541 2542 2543 } 2617 if (double_format == unknown_format) { 2618 unsigned char sign; 2619 int e; 2620 unsigned int fhi, flo; 2621 double x; 2622 int incr = 1; 2623 2624 if (le) { 2625 p += 7; 2626 incr = -1; 2627 } 2628 2629 /* First byte */ 2630 sign = (*p >> 7) & 1; 2631 e = (*p & 0x7F) << 4; 2632 2633 p += incr; 2634 2635 /* Second byte */ 2636 e |= (*p >> 4) & 0xF; 2637 fhi = (*p & 0xF) << 24; 2638 p += incr; 2639 2640 if (e == 2047) { 2641 PyErr_SetString( 2642 PyExc_ValueError, 2643 "can't unpack IEEE 754 special value " 2644 "on non-IEEE platform"); 2645 return -1.0; 2646 } 2647 2648 /* Third byte */ 2649 fhi |= *p << 16; 2650 p += incr; 2651 2652 /* Fourth byte */ 2653 fhi |= *p << 8; 2654 p += incr; 2655 2656 /* Fifth byte */ 2657 fhi |= *p; 2658 p += incr; 2659 2660 /* Sixth byte */ 2661 flo = *p << 16; 2662 p += incr; 2663 2664 /* Seventh byte */ 2665 flo |= *p << 8; 2666 p += incr; 2667 2668 /* Eighth byte */ 2669 flo |= *p; 2670 2671 x = (double)fhi + (double)flo / 16777216.0; /* 2**24 */ 2672 x /= 268435456.0; /* 2**28 */ 2673 2674 if (e == 0) 2675 e = -1022; 2676 else { 2677 x += 1.0; 2678 e -= 1023; 2679 } 2680 x = ldexp(x, e); 2681 2682 if (sign) 2683 x = -x; 2684 2685 return x; 2686 } 2687 else { 2688 double x; 2689 2690 if ((double_format == ieee_little_endian_format && !le) 2691 || (double_format == ieee_big_endian_format && le)) { 2692 char buf[8]; 2693 char *d = &buf[7]; 2694 int i; 2695 2696 for (i = 0; i < 8; i++) { 2697 *d-- = *p++; 2698 } 2699 memcpy(&x, buf, 8); 2700 } 2701 else { 2702 memcpy(&x, p, 8); 2703 } 2704 2705 return x; 2706 } 2707 }
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