| 1 | /* numeric.c |
| 2 | * |
| 3 | * Copyright (C) 1993, 1994, 1995, 1996, 1997, 1998, 1999, 2000, 2001, |
| 4 | * 2002, 2003, 2004, 2005, 2006, 2007, 2008 by Larry Wall and others |
| 5 | * |
| 6 | * You may distribute under the terms of either the GNU General Public |
| 7 | * License or the Artistic License, as specified in the README file. |
| 8 | * |
| 9 | */ |
| 10 | |
| 11 | /* |
| 12 | * "That only makes eleven (plus one mislaid) and not fourteen, |
| 13 | * unless wizards count differently to other people." --Beorn |
| 14 | * |
| 15 | * [p.115 of _The Hobbit_: "Queer Lodgings"] |
| 16 | */ |
| 17 | |
| 18 | /* |
| 19 | =head1 Numeric functions |
| 20 | |
| 21 | This file contains all the stuff needed by perl for manipulating numeric |
| 22 | values, including such things as replacements for the OS's atof() function |
| 23 | |
| 24 | =cut |
| 25 | |
| 26 | */ |
| 27 | |
| 28 | #include "EXTERN.h" |
| 29 | #define PERL_IN_NUMERIC_C |
| 30 | #include "perl.h" |
| 31 | |
| 32 | U32 |
| 33 | Perl_cast_ulong(pTHX_ NV f) |
| 34 | { |
| 35 | PERL_UNUSED_CONTEXT; |
| 36 | if (f < 0.0) |
| 37 | return f < I32_MIN ? (U32) I32_MIN : (U32)(I32) f; |
| 38 | if (f < U32_MAX_P1) { |
| 39 | #if CASTFLAGS & 2 |
| 40 | if (f < U32_MAX_P1_HALF) |
| 41 | return (U32) f; |
| 42 | f -= U32_MAX_P1_HALF; |
| 43 | return ((U32) f) | (1 + U32_MAX >> 1); |
| 44 | #else |
| 45 | return (U32) f; |
| 46 | #endif |
| 47 | } |
| 48 | return f > 0 ? U32_MAX : 0 /* NaN */; |
| 49 | } |
| 50 | |
| 51 | I32 |
| 52 | Perl_cast_i32(pTHX_ NV f) |
| 53 | { |
| 54 | PERL_UNUSED_CONTEXT; |
| 55 | if (f < I32_MAX_P1) |
| 56 | return f < I32_MIN ? I32_MIN : (I32) f; |
| 57 | if (f < U32_MAX_P1) { |
| 58 | #if CASTFLAGS & 2 |
| 59 | if (f < U32_MAX_P1_HALF) |
| 60 | return (I32)(U32) f; |
| 61 | f -= U32_MAX_P1_HALF; |
| 62 | return (I32)(((U32) f) | (1 + U32_MAX >> 1)); |
| 63 | #else |
| 64 | return (I32)(U32) f; |
| 65 | #endif |
| 66 | } |
| 67 | return f > 0 ? (I32)U32_MAX : 0 /* NaN */; |
| 68 | } |
| 69 | |
| 70 | IV |
| 71 | Perl_cast_iv(pTHX_ NV f) |
| 72 | { |
| 73 | PERL_UNUSED_CONTEXT; |
| 74 | if (f < IV_MAX_P1) |
| 75 | return f < IV_MIN ? IV_MIN : (IV) f; |
| 76 | if (f < UV_MAX_P1) { |
| 77 | #if CASTFLAGS & 2 |
| 78 | /* For future flexibility allowing for sizeof(UV) >= sizeof(IV) */ |
| 79 | if (f < UV_MAX_P1_HALF) |
| 80 | return (IV)(UV) f; |
| 81 | f -= UV_MAX_P1_HALF; |
| 82 | return (IV)(((UV) f) | (1 + UV_MAX >> 1)); |
| 83 | #else |
| 84 | return (IV)(UV) f; |
| 85 | #endif |
| 86 | } |
| 87 | return f > 0 ? (IV)UV_MAX : 0 /* NaN */; |
| 88 | } |
| 89 | |
| 90 | UV |
| 91 | Perl_cast_uv(pTHX_ NV f) |
| 92 | { |
| 93 | PERL_UNUSED_CONTEXT; |
| 94 | if (f < 0.0) |
| 95 | return f < IV_MIN ? (UV) IV_MIN : (UV)(IV) f; |
| 96 | if (f < UV_MAX_P1) { |
| 97 | #if CASTFLAGS & 2 |
| 98 | if (f < UV_MAX_P1_HALF) |
| 99 | return (UV) f; |
| 100 | f -= UV_MAX_P1_HALF; |
| 101 | return ((UV) f) | (1 + UV_MAX >> 1); |
| 102 | #else |
| 103 | return (UV) f; |
| 104 | #endif |
| 105 | } |
| 106 | return f > 0 ? UV_MAX : 0 /* NaN */; |
| 107 | } |
| 108 | |
| 109 | /* |
| 110 | =for apidoc grok_bin |
| 111 | |
| 112 | converts a string representing a binary number to numeric form. |
| 113 | |
| 114 | On entry I<start> and I<*len> give the string to scan, I<*flags> gives |
| 115 | conversion flags, and I<result> should be NULL or a pointer to an NV. |
| 116 | The scan stops at the end of the string, or the first invalid character. |
| 117 | Unless C<PERL_SCAN_SILENT_ILLDIGIT> is set in I<*flags>, encountering an |
| 118 | invalid character will also trigger a warning. |
| 119 | On return I<*len> is set to the length of the scanned string, |
| 120 | and I<*flags> gives output flags. |
| 121 | |
| 122 | If the value is <= C<UV_MAX> it is returned as a UV, the output flags are clear, |
| 123 | and nothing is written to I<*result>. If the value is > UV_MAX C<grok_bin> |
| 124 | returns UV_MAX, sets C<PERL_SCAN_GREATER_THAN_UV_MAX> in the output flags, |
| 125 | and writes the value to I<*result> (or the value is discarded if I<result> |
| 126 | is NULL). |
| 127 | |
| 128 | The binary number may optionally be prefixed with "0b" or "b" unless |
| 129 | C<PERL_SCAN_DISALLOW_PREFIX> is set in I<*flags> on entry. If |
| 130 | C<PERL_SCAN_ALLOW_UNDERSCORES> is set in I<*flags> then the binary |
| 131 | number may use '_' characters to separate digits. |
| 132 | |
| 133 | =cut |
| 134 | |
| 135 | Not documented yet because experimental is C<PERL_SCAN_SILENT_NON_PORTABLE |
| 136 | which suppresses any message for non-portable numbers that are still valid |
| 137 | on this platform. |
| 138 | */ |
| 139 | |
| 140 | UV |
| 141 | Perl_grok_bin(pTHX_ const char *start, STRLEN *len_p, I32 *flags, NV *result) |
| 142 | { |
| 143 | const char *s = start; |
| 144 | STRLEN len = *len_p; |
| 145 | UV value = 0; |
| 146 | NV value_nv = 0; |
| 147 | |
| 148 | const UV max_div_2 = UV_MAX / 2; |
| 149 | const bool allow_underscores = cBOOL(*flags & PERL_SCAN_ALLOW_UNDERSCORES); |
| 150 | bool overflowed = FALSE; |
| 151 | char bit; |
| 152 | |
| 153 | PERL_ARGS_ASSERT_GROK_BIN; |
| 154 | |
| 155 | if (!(*flags & PERL_SCAN_DISALLOW_PREFIX)) { |
| 156 | /* strip off leading b or 0b. |
| 157 | for compatibility silently suffer "b" and "0b" as valid binary |
| 158 | numbers. */ |
| 159 | if (len >= 1) { |
| 160 | if (s[0] == 'b' || s[0] == 'B') { |
| 161 | s++; |
| 162 | len--; |
| 163 | } |
| 164 | else if (len >= 2 && s[0] == '0' && (s[1] == 'b' || s[1] == 'B')) { |
| 165 | s+=2; |
| 166 | len-=2; |
| 167 | } |
| 168 | } |
| 169 | } |
| 170 | |
| 171 | for (; len-- && (bit = *s); s++) { |
| 172 | if (bit == '0' || bit == '1') { |
| 173 | /* Write it in this wonky order with a goto to attempt to get the |
| 174 | compiler to make the common case integer-only loop pretty tight. |
| 175 | With gcc seems to be much straighter code than old scan_bin. */ |
| 176 | redo: |
| 177 | if (!overflowed) { |
| 178 | if (value <= max_div_2) { |
| 179 | value = (value << 1) | (bit - '0'); |
| 180 | continue; |
| 181 | } |
| 182 | /* Bah. We're just overflowed. */ |
| 183 | /* diag_listed_as: Integer overflow in %s number */ |
| 184 | Perl_ck_warner_d(aTHX_ packWARN(WARN_OVERFLOW), |
| 185 | "Integer overflow in binary number"); |
| 186 | overflowed = TRUE; |
| 187 | value_nv = (NV) value; |
| 188 | } |
| 189 | value_nv *= 2.0; |
| 190 | /* If an NV has not enough bits in its mantissa to |
| 191 | * represent a UV this summing of small low-order numbers |
| 192 | * is a waste of time (because the NV cannot preserve |
| 193 | * the low-order bits anyway): we could just remember when |
| 194 | * did we overflow and in the end just multiply value_nv by the |
| 195 | * right amount. */ |
| 196 | value_nv += (NV)(bit - '0'); |
| 197 | continue; |
| 198 | } |
| 199 | if (bit == '_' && len && allow_underscores && (bit = s[1]) |
| 200 | && (bit == '0' || bit == '1')) |
| 201 | { |
| 202 | --len; |
| 203 | ++s; |
| 204 | goto redo; |
| 205 | } |
| 206 | if (!(*flags & PERL_SCAN_SILENT_ILLDIGIT)) |
| 207 | Perl_ck_warner(aTHX_ packWARN(WARN_DIGIT), |
| 208 | "Illegal binary digit '%c' ignored", *s); |
| 209 | break; |
| 210 | } |
| 211 | |
| 212 | if ( ( overflowed && value_nv > 4294967295.0) |
| 213 | #if UVSIZE > 4 |
| 214 | || (!overflowed && value > 0xffffffff |
| 215 | && ! (*flags & PERL_SCAN_SILENT_NON_PORTABLE)) |
| 216 | #endif |
| 217 | ) { |
| 218 | Perl_ck_warner(aTHX_ packWARN(WARN_PORTABLE), |
| 219 | "Binary number > 0b11111111111111111111111111111111 non-portable"); |
| 220 | } |
| 221 | *len_p = s - start; |
| 222 | if (!overflowed) { |
| 223 | *flags = 0; |
| 224 | return value; |
| 225 | } |
| 226 | *flags = PERL_SCAN_GREATER_THAN_UV_MAX; |
| 227 | if (result) |
| 228 | *result = value_nv; |
| 229 | return UV_MAX; |
| 230 | } |
| 231 | |
| 232 | /* |
| 233 | =for apidoc grok_hex |
| 234 | |
| 235 | converts a string representing a hex number to numeric form. |
| 236 | |
| 237 | On entry I<start> and I<*len> give the string to scan, I<*flags> gives |
| 238 | conversion flags, and I<result> should be NULL or a pointer to an NV. |
| 239 | The scan stops at the end of the string, or the first invalid character. |
| 240 | Unless C<PERL_SCAN_SILENT_ILLDIGIT> is set in I<*flags>, encountering an |
| 241 | invalid character will also trigger a warning. |
| 242 | On return I<*len> is set to the length of the scanned string, |
| 243 | and I<*flags> gives output flags. |
| 244 | |
| 245 | If the value is <= UV_MAX it is returned as a UV, the output flags are clear, |
| 246 | and nothing is written to I<*result>. If the value is > UV_MAX C<grok_hex> |
| 247 | returns UV_MAX, sets C<PERL_SCAN_GREATER_THAN_UV_MAX> in the output flags, |
| 248 | and writes the value to I<*result> (or the value is discarded if I<result> |
| 249 | is NULL). |
| 250 | |
| 251 | The hex number may optionally be prefixed with "0x" or "x" unless |
| 252 | C<PERL_SCAN_DISALLOW_PREFIX> is set in I<*flags> on entry. If |
| 253 | C<PERL_SCAN_ALLOW_UNDERSCORES> is set in I<*flags> then the hex |
| 254 | number may use '_' characters to separate digits. |
| 255 | |
| 256 | =cut |
| 257 | |
| 258 | Not documented yet because experimental is C<PERL_SCAN_SILENT_NON_PORTABLE |
| 259 | which suppresses any message for non-portable numbers that are still valid |
| 260 | on this platform. |
| 261 | */ |
| 262 | |
| 263 | UV |
| 264 | Perl_grok_hex(pTHX_ const char *start, STRLEN *len_p, I32 *flags, NV *result) |
| 265 | { |
| 266 | dVAR; |
| 267 | const char *s = start; |
| 268 | STRLEN len = *len_p; |
| 269 | UV value = 0; |
| 270 | NV value_nv = 0; |
| 271 | const UV max_div_16 = UV_MAX / 16; |
| 272 | const bool allow_underscores = cBOOL(*flags & PERL_SCAN_ALLOW_UNDERSCORES); |
| 273 | bool overflowed = FALSE; |
| 274 | |
| 275 | PERL_ARGS_ASSERT_GROK_HEX; |
| 276 | |
| 277 | if (!(*flags & PERL_SCAN_DISALLOW_PREFIX)) { |
| 278 | /* strip off leading x or 0x. |
| 279 | for compatibility silently suffer "x" and "0x" as valid hex numbers. |
| 280 | */ |
| 281 | if (len >= 1) { |
| 282 | if (s[0] == 'x' || s[0] == 'X') { |
| 283 | s++; |
| 284 | len--; |
| 285 | } |
| 286 | else if (len >= 2 && s[0] == '0' && (s[1] == 'x' || s[1] == 'X')) { |
| 287 | s+=2; |
| 288 | len-=2; |
| 289 | } |
| 290 | } |
| 291 | } |
| 292 | |
| 293 | for (; len-- && *s; s++) { |
| 294 | const char *hexdigit = strchr(PL_hexdigit, *s); |
| 295 | if (hexdigit) { |
| 296 | /* Write it in this wonky order with a goto to attempt to get the |
| 297 | compiler to make the common case integer-only loop pretty tight. |
| 298 | With gcc seems to be much straighter code than old scan_hex. */ |
| 299 | redo: |
| 300 | if (!overflowed) { |
| 301 | if (value <= max_div_16) { |
| 302 | value = (value << 4) | ((hexdigit - PL_hexdigit) & 15); |
| 303 | continue; |
| 304 | } |
| 305 | /* Bah. We're just overflowed. */ |
| 306 | /* diag_listed_as: Integer overflow in %s number */ |
| 307 | Perl_ck_warner_d(aTHX_ packWARN(WARN_OVERFLOW), |
| 308 | "Integer overflow in hexadecimal number"); |
| 309 | overflowed = TRUE; |
| 310 | value_nv = (NV) value; |
| 311 | } |
| 312 | value_nv *= 16.0; |
| 313 | /* If an NV has not enough bits in its mantissa to |
| 314 | * represent a UV this summing of small low-order numbers |
| 315 | * is a waste of time (because the NV cannot preserve |
| 316 | * the low-order bits anyway): we could just remember when |
| 317 | * did we overflow and in the end just multiply value_nv by the |
| 318 | * right amount of 16-tuples. */ |
| 319 | value_nv += (NV)((hexdigit - PL_hexdigit) & 15); |
| 320 | continue; |
| 321 | } |
| 322 | if (*s == '_' && len && allow_underscores && s[1] |
| 323 | && (hexdigit = strchr(PL_hexdigit, s[1]))) |
| 324 | { |
| 325 | --len; |
| 326 | ++s; |
| 327 | goto redo; |
| 328 | } |
| 329 | if (!(*flags & PERL_SCAN_SILENT_ILLDIGIT)) |
| 330 | Perl_ck_warner(aTHX_ packWARN(WARN_DIGIT), |
| 331 | "Illegal hexadecimal digit '%c' ignored", *s); |
| 332 | break; |
| 333 | } |
| 334 | |
| 335 | if ( ( overflowed && value_nv > 4294967295.0) |
| 336 | #if UVSIZE > 4 |
| 337 | || (!overflowed && value > 0xffffffff |
| 338 | && ! (*flags & PERL_SCAN_SILENT_NON_PORTABLE)) |
| 339 | #endif |
| 340 | ) { |
| 341 | Perl_ck_warner(aTHX_ packWARN(WARN_PORTABLE), |
| 342 | "Hexadecimal number > 0xffffffff non-portable"); |
| 343 | } |
| 344 | *len_p = s - start; |
| 345 | if (!overflowed) { |
| 346 | *flags = 0; |
| 347 | return value; |
| 348 | } |
| 349 | *flags = PERL_SCAN_GREATER_THAN_UV_MAX; |
| 350 | if (result) |
| 351 | *result = value_nv; |
| 352 | return UV_MAX; |
| 353 | } |
| 354 | |
| 355 | /* |
| 356 | =for apidoc grok_oct |
| 357 | |
| 358 | converts a string representing an octal number to numeric form. |
| 359 | |
| 360 | On entry I<start> and I<*len> give the string to scan, I<*flags> gives |
| 361 | conversion flags, and I<result> should be NULL or a pointer to an NV. |
| 362 | The scan stops at the end of the string, or the first invalid character. |
| 363 | Unless C<PERL_SCAN_SILENT_ILLDIGIT> is set in I<*flags>, encountering an |
| 364 | 8 or 9 will also trigger a warning. |
| 365 | On return I<*len> is set to the length of the scanned string, |
| 366 | and I<*flags> gives output flags. |
| 367 | |
| 368 | If the value is <= UV_MAX it is returned as a UV, the output flags are clear, |
| 369 | and nothing is written to I<*result>. If the value is > UV_MAX C<grok_oct> |
| 370 | returns UV_MAX, sets C<PERL_SCAN_GREATER_THAN_UV_MAX> in the output flags, |
| 371 | and writes the value to I<*result> (or the value is discarded if I<result> |
| 372 | is NULL). |
| 373 | |
| 374 | If C<PERL_SCAN_ALLOW_UNDERSCORES> is set in I<*flags> then the octal |
| 375 | number may use '_' characters to separate digits. |
| 376 | |
| 377 | =cut |
| 378 | |
| 379 | Not documented yet because experimental is C<PERL_SCAN_SILENT_NON_PORTABLE> |
| 380 | which suppresses any message for non-portable numbers, but which are valid |
| 381 | on this platform. |
| 382 | */ |
| 383 | |
| 384 | UV |
| 385 | Perl_grok_oct(pTHX_ const char *start, STRLEN *len_p, I32 *flags, NV *result) |
| 386 | { |
| 387 | const char *s = start; |
| 388 | STRLEN len = *len_p; |
| 389 | UV value = 0; |
| 390 | NV value_nv = 0; |
| 391 | const UV max_div_8 = UV_MAX / 8; |
| 392 | const bool allow_underscores = cBOOL(*flags & PERL_SCAN_ALLOW_UNDERSCORES); |
| 393 | bool overflowed = FALSE; |
| 394 | |
| 395 | PERL_ARGS_ASSERT_GROK_OCT; |
| 396 | |
| 397 | for (; len-- && *s; s++) { |
| 398 | /* gcc 2.95 optimiser not smart enough to figure that this subtraction |
| 399 | out front allows slicker code. */ |
| 400 | int digit = *s - '0'; |
| 401 | if (digit >= 0 && digit <= 7) { |
| 402 | /* Write it in this wonky order with a goto to attempt to get the |
| 403 | compiler to make the common case integer-only loop pretty tight. |
| 404 | */ |
| 405 | redo: |
| 406 | if (!overflowed) { |
| 407 | if (value <= max_div_8) { |
| 408 | value = (value << 3) | digit; |
| 409 | continue; |
| 410 | } |
| 411 | /* Bah. We're just overflowed. */ |
| 412 | /* diag_listed_as: Integer overflow in %s number */ |
| 413 | Perl_ck_warner_d(aTHX_ packWARN(WARN_OVERFLOW), |
| 414 | "Integer overflow in octal number"); |
| 415 | overflowed = TRUE; |
| 416 | value_nv = (NV) value; |
| 417 | } |
| 418 | value_nv *= 8.0; |
| 419 | /* If an NV has not enough bits in its mantissa to |
| 420 | * represent a UV this summing of small low-order numbers |
| 421 | * is a waste of time (because the NV cannot preserve |
| 422 | * the low-order bits anyway): we could just remember when |
| 423 | * did we overflow and in the end just multiply value_nv by the |
| 424 | * right amount of 8-tuples. */ |
| 425 | value_nv += (NV)digit; |
| 426 | continue; |
| 427 | } |
| 428 | if (digit == ('_' - '0') && len && allow_underscores |
| 429 | && (digit = s[1] - '0') && (digit >= 0 && digit <= 7)) |
| 430 | { |
| 431 | --len; |
| 432 | ++s; |
| 433 | goto redo; |
| 434 | } |
| 435 | /* Allow \octal to work the DWIM way (that is, stop scanning |
| 436 | * as soon as non-octal characters are seen, complain only if |
| 437 | * someone seems to want to use the digits eight and nine). */ |
| 438 | if (digit == 8 || digit == 9) { |
| 439 | if (!(*flags & PERL_SCAN_SILENT_ILLDIGIT)) |
| 440 | Perl_ck_warner(aTHX_ packWARN(WARN_DIGIT), |
| 441 | "Illegal octal digit '%c' ignored", *s); |
| 442 | } |
| 443 | break; |
| 444 | } |
| 445 | |
| 446 | if ( ( overflowed && value_nv > 4294967295.0) |
| 447 | #if UVSIZE > 4 |
| 448 | || (!overflowed && value > 0xffffffff |
| 449 | && ! (*flags & PERL_SCAN_SILENT_NON_PORTABLE)) |
| 450 | #endif |
| 451 | ) { |
| 452 | Perl_ck_warner(aTHX_ packWARN(WARN_PORTABLE), |
| 453 | "Octal number > 037777777777 non-portable"); |
| 454 | } |
| 455 | *len_p = s - start; |
| 456 | if (!overflowed) { |
| 457 | *flags = 0; |
| 458 | return value; |
| 459 | } |
| 460 | *flags = PERL_SCAN_GREATER_THAN_UV_MAX; |
| 461 | if (result) |
| 462 | *result = value_nv; |
| 463 | return UV_MAX; |
| 464 | } |
| 465 | |
| 466 | /* |
| 467 | =for apidoc scan_bin |
| 468 | |
| 469 | For backwards compatibility. Use C<grok_bin> instead. |
| 470 | |
| 471 | =for apidoc scan_hex |
| 472 | |
| 473 | For backwards compatibility. Use C<grok_hex> instead. |
| 474 | |
| 475 | =for apidoc scan_oct |
| 476 | |
| 477 | For backwards compatibility. Use C<grok_oct> instead. |
| 478 | |
| 479 | =cut |
| 480 | */ |
| 481 | |
| 482 | NV |
| 483 | Perl_scan_bin(pTHX_ const char *start, STRLEN len, STRLEN *retlen) |
| 484 | { |
| 485 | NV rnv; |
| 486 | I32 flags = *retlen ? PERL_SCAN_ALLOW_UNDERSCORES : 0; |
| 487 | const UV ruv = grok_bin (start, &len, &flags, &rnv); |
| 488 | |
| 489 | PERL_ARGS_ASSERT_SCAN_BIN; |
| 490 | |
| 491 | *retlen = len; |
| 492 | return (flags & PERL_SCAN_GREATER_THAN_UV_MAX) ? rnv : (NV)ruv; |
| 493 | } |
| 494 | |
| 495 | NV |
| 496 | Perl_scan_oct(pTHX_ const char *start, STRLEN len, STRLEN *retlen) |
| 497 | { |
| 498 | NV rnv; |
| 499 | I32 flags = *retlen ? PERL_SCAN_ALLOW_UNDERSCORES : 0; |
| 500 | const UV ruv = grok_oct (start, &len, &flags, &rnv); |
| 501 | |
| 502 | PERL_ARGS_ASSERT_SCAN_OCT; |
| 503 | |
| 504 | *retlen = len; |
| 505 | return (flags & PERL_SCAN_GREATER_THAN_UV_MAX) ? rnv : (NV)ruv; |
| 506 | } |
| 507 | |
| 508 | NV |
| 509 | Perl_scan_hex(pTHX_ const char *start, STRLEN len, STRLEN *retlen) |
| 510 | { |
| 511 | NV rnv; |
| 512 | I32 flags = *retlen ? PERL_SCAN_ALLOW_UNDERSCORES : 0; |
| 513 | const UV ruv = grok_hex (start, &len, &flags, &rnv); |
| 514 | |
| 515 | PERL_ARGS_ASSERT_SCAN_HEX; |
| 516 | |
| 517 | *retlen = len; |
| 518 | return (flags & PERL_SCAN_GREATER_THAN_UV_MAX) ? rnv : (NV)ruv; |
| 519 | } |
| 520 | |
| 521 | /* |
| 522 | =for apidoc grok_numeric_radix |
| 523 | |
| 524 | Scan and skip for a numeric decimal separator (radix). |
| 525 | |
| 526 | =cut |
| 527 | */ |
| 528 | bool |
| 529 | Perl_grok_numeric_radix(pTHX_ const char **sp, const char *send) |
| 530 | { |
| 531 | #ifdef USE_LOCALE_NUMERIC |
| 532 | dVAR; |
| 533 | |
| 534 | PERL_ARGS_ASSERT_GROK_NUMERIC_RADIX; |
| 535 | |
| 536 | if (PL_numeric_radix_sv && IN_SOME_LOCALE_FORM) { |
| 537 | STRLEN len; |
| 538 | const char * const radix = SvPV(PL_numeric_radix_sv, len); |
| 539 | if (*sp + len <= send && memEQ(*sp, radix, len)) { |
| 540 | *sp += len; |
| 541 | return TRUE; |
| 542 | } |
| 543 | } |
| 544 | /* always try "." if numeric radix didn't match because |
| 545 | * we may have data from different locales mixed */ |
| 546 | #endif |
| 547 | |
| 548 | PERL_ARGS_ASSERT_GROK_NUMERIC_RADIX; |
| 549 | |
| 550 | if (*sp < send && **sp == '.') { |
| 551 | ++*sp; |
| 552 | return TRUE; |
| 553 | } |
| 554 | return FALSE; |
| 555 | } |
| 556 | |
| 557 | /* |
| 558 | =for apidoc grok_number |
| 559 | |
| 560 | Recognise (or not) a number. The type of the number is returned |
| 561 | (0 if unrecognised), otherwise it is a bit-ORed combination of |
| 562 | IS_NUMBER_IN_UV, IS_NUMBER_GREATER_THAN_UV_MAX, IS_NUMBER_NOT_INT, |
| 563 | IS_NUMBER_NEG, IS_NUMBER_INFINITY, IS_NUMBER_NAN (defined in perl.h). |
| 564 | |
| 565 | If the value of the number can fit an in UV, it is returned in the *valuep |
| 566 | IS_NUMBER_IN_UV will be set to indicate that *valuep is valid, IS_NUMBER_IN_UV |
| 567 | will never be set unless *valuep is valid, but *valuep may have been assigned |
| 568 | to during processing even though IS_NUMBER_IN_UV is not set on return. |
| 569 | If valuep is NULL, IS_NUMBER_IN_UV will be set for the same cases as when |
| 570 | valuep is non-NULL, but no actual assignment (or SEGV) will occur. |
| 571 | |
| 572 | IS_NUMBER_NOT_INT will be set with IS_NUMBER_IN_UV if trailing decimals were |
| 573 | seen (in which case *valuep gives the true value truncated to an integer), and |
| 574 | IS_NUMBER_NEG if the number is negative (in which case *valuep holds the |
| 575 | absolute value). IS_NUMBER_IN_UV is not set if e notation was used or the |
| 576 | number is larger than a UV. |
| 577 | |
| 578 | =cut |
| 579 | */ |
| 580 | int |
| 581 | Perl_grok_number(pTHX_ const char *pv, STRLEN len, UV *valuep) |
| 582 | { |
| 583 | const char *s = pv; |
| 584 | const char * const send = pv + len; |
| 585 | const UV max_div_10 = UV_MAX / 10; |
| 586 | const char max_mod_10 = UV_MAX % 10; |
| 587 | int numtype = 0; |
| 588 | int sawinf = 0; |
| 589 | int sawnan = 0; |
| 590 | |
| 591 | PERL_ARGS_ASSERT_GROK_NUMBER; |
| 592 | |
| 593 | while (s < send && isSPACE(*s)) |
| 594 | s++; |
| 595 | if (s == send) { |
| 596 | return 0; |
| 597 | } else if (*s == '-') { |
| 598 | s++; |
| 599 | numtype = IS_NUMBER_NEG; |
| 600 | } |
| 601 | else if (*s == '+') |
| 602 | s++; |
| 603 | |
| 604 | if (s == send) |
| 605 | return 0; |
| 606 | |
| 607 | /* next must be digit or the radix separator or beginning of infinity */ |
| 608 | if (isDIGIT(*s)) { |
| 609 | /* UVs are at least 32 bits, so the first 9 decimal digits cannot |
| 610 | overflow. */ |
| 611 | UV value = *s - '0'; |
| 612 | /* This construction seems to be more optimiser friendly. |
| 613 | (without it gcc does the isDIGIT test and the *s - '0' separately) |
| 614 | With it gcc on arm is managing 6 instructions (6 cycles) per digit. |
| 615 | In theory the optimiser could deduce how far to unroll the loop |
| 616 | before checking for overflow. */ |
| 617 | if (++s < send) { |
| 618 | int digit = *s - '0'; |
| 619 | if (digit >= 0 && digit <= 9) { |
| 620 | value = value * 10 + digit; |
| 621 | if (++s < send) { |
| 622 | digit = *s - '0'; |
| 623 | if (digit >= 0 && digit <= 9) { |
| 624 | value = value * 10 + digit; |
| 625 | if (++s < send) { |
| 626 | digit = *s - '0'; |
| 627 | if (digit >= 0 && digit <= 9) { |
| 628 | value = value * 10 + digit; |
| 629 | if (++s < send) { |
| 630 | digit = *s - '0'; |
| 631 | if (digit >= 0 && digit <= 9) { |
| 632 | value = value * 10 + digit; |
| 633 | if (++s < send) { |
| 634 | digit = *s - '0'; |
| 635 | if (digit >= 0 && digit <= 9) { |
| 636 | value = value * 10 + digit; |
| 637 | if (++s < send) { |
| 638 | digit = *s - '0'; |
| 639 | if (digit >= 0 && digit <= 9) { |
| 640 | value = value * 10 + digit; |
| 641 | if (++s < send) { |
| 642 | digit = *s - '0'; |
| 643 | if (digit >= 0 && digit <= 9) { |
| 644 | value = value * 10 + digit; |
| 645 | if (++s < send) { |
| 646 | digit = *s - '0'; |
| 647 | if (digit >= 0 && digit <= 9) { |
| 648 | value = value * 10 + digit; |
| 649 | if (++s < send) { |
| 650 | /* Now got 9 digits, so need to check |
| 651 | each time for overflow. */ |
| 652 | digit = *s - '0'; |
| 653 | while (digit >= 0 && digit <= 9 |
| 654 | && (value < max_div_10 |
| 655 | || (value == max_div_10 |
| 656 | && digit <= max_mod_10))) { |
| 657 | value = value * 10 + digit; |
| 658 | if (++s < send) |
| 659 | digit = *s - '0'; |
| 660 | else |
| 661 | break; |
| 662 | } |
| 663 | if (digit >= 0 && digit <= 9 |
| 664 | && (s < send)) { |
| 665 | /* value overflowed. |
| 666 | skip the remaining digits, don't |
| 667 | worry about setting *valuep. */ |
| 668 | do { |
| 669 | s++; |
| 670 | } while (s < send && isDIGIT(*s)); |
| 671 | numtype |= |
| 672 | IS_NUMBER_GREATER_THAN_UV_MAX; |
| 673 | goto skip_value; |
| 674 | } |
| 675 | } |
| 676 | } |
| 677 | } |
| 678 | } |
| 679 | } |
| 680 | } |
| 681 | } |
| 682 | } |
| 683 | } |
| 684 | } |
| 685 | } |
| 686 | } |
| 687 | } |
| 688 | } |
| 689 | } |
| 690 | } |
| 691 | } |
| 692 | numtype |= IS_NUMBER_IN_UV; |
| 693 | if (valuep) |
| 694 | *valuep = value; |
| 695 | |
| 696 | skip_value: |
| 697 | if (GROK_NUMERIC_RADIX(&s, send)) { |
| 698 | numtype |= IS_NUMBER_NOT_INT; |
| 699 | while (s < send && isDIGIT(*s)) /* optional digits after the radix */ |
| 700 | s++; |
| 701 | } |
| 702 | } |
| 703 | else if (GROK_NUMERIC_RADIX(&s, send)) { |
| 704 | numtype |= IS_NUMBER_NOT_INT | IS_NUMBER_IN_UV; /* valuep assigned below */ |
| 705 | /* no digits before the radix means we need digits after it */ |
| 706 | if (s < send && isDIGIT(*s)) { |
| 707 | do { |
| 708 | s++; |
| 709 | } while (s < send && isDIGIT(*s)); |
| 710 | if (valuep) { |
| 711 | /* integer approximation is valid - it's 0. */ |
| 712 | *valuep = 0; |
| 713 | } |
| 714 | } |
| 715 | else |
| 716 | return 0; |
| 717 | } else if (*s == 'I' || *s == 'i') { |
| 718 | s++; if (s == send || (*s != 'N' && *s != 'n')) return 0; |
| 719 | s++; if (s == send || (*s != 'F' && *s != 'f')) return 0; |
| 720 | s++; if (s < send && (*s == 'I' || *s == 'i')) { |
| 721 | s++; if (s == send || (*s != 'N' && *s != 'n')) return 0; |
| 722 | s++; if (s == send || (*s != 'I' && *s != 'i')) return 0; |
| 723 | s++; if (s == send || (*s != 'T' && *s != 't')) return 0; |
| 724 | s++; if (s == send || (*s != 'Y' && *s != 'y')) return 0; |
| 725 | s++; |
| 726 | } |
| 727 | sawinf = 1; |
| 728 | } else if (*s == 'N' || *s == 'n') { |
| 729 | /* XXX TODO: There are signaling NaNs and quiet NaNs. */ |
| 730 | s++; if (s == send || (*s != 'A' && *s != 'a')) return 0; |
| 731 | s++; if (s == send || (*s != 'N' && *s != 'n')) return 0; |
| 732 | s++; |
| 733 | sawnan = 1; |
| 734 | } else |
| 735 | return 0; |
| 736 | |
| 737 | if (sawinf) { |
| 738 | numtype &= IS_NUMBER_NEG; /* Keep track of sign */ |
| 739 | numtype |= IS_NUMBER_INFINITY | IS_NUMBER_NOT_INT; |
| 740 | } else if (sawnan) { |
| 741 | numtype &= IS_NUMBER_NEG; /* Keep track of sign */ |
| 742 | numtype |= IS_NUMBER_NAN | IS_NUMBER_NOT_INT; |
| 743 | } else if (s < send) { |
| 744 | /* we can have an optional exponent part */ |
| 745 | if (*s == 'e' || *s == 'E') { |
| 746 | /* The only flag we keep is sign. Blow away any "it's UV" */ |
| 747 | numtype &= IS_NUMBER_NEG; |
| 748 | numtype |= IS_NUMBER_NOT_INT; |
| 749 | s++; |
| 750 | if (s < send && (*s == '-' || *s == '+')) |
| 751 | s++; |
| 752 | if (s < send && isDIGIT(*s)) { |
| 753 | do { |
| 754 | s++; |
| 755 | } while (s < send && isDIGIT(*s)); |
| 756 | } |
| 757 | else |
| 758 | return 0; |
| 759 | } |
| 760 | } |
| 761 | while (s < send && isSPACE(*s)) |
| 762 | s++; |
| 763 | if (s >= send) |
| 764 | return numtype; |
| 765 | if (len == 10 && memEQ(pv, "0 but true", 10)) { |
| 766 | if (valuep) |
| 767 | *valuep = 0; |
| 768 | return IS_NUMBER_IN_UV; |
| 769 | } |
| 770 | return 0; |
| 771 | } |
| 772 | |
| 773 | STATIC NV |
| 774 | S_mulexp10(NV value, I32 exponent) |
| 775 | { |
| 776 | NV result = 1.0; |
| 777 | NV power = 10.0; |
| 778 | bool negative = 0; |
| 779 | I32 bit; |
| 780 | |
| 781 | if (exponent == 0) |
| 782 | return value; |
| 783 | if (value == 0) |
| 784 | return (NV)0; |
| 785 | |
| 786 | /* On OpenVMS VAX we by default use the D_FLOAT double format, |
| 787 | * and that format does not have *easy* capabilities [1] for |
| 788 | * overflowing doubles 'silently' as IEEE fp does. We also need |
| 789 | * to support G_FLOAT on both VAX and Alpha, and though the exponent |
| 790 | * range is much larger than D_FLOAT it still doesn't do silent |
| 791 | * overflow. Therefore we need to detect early whether we would |
| 792 | * overflow (this is the behaviour of the native string-to-float |
| 793 | * conversion routines, and therefore of native applications, too). |
| 794 | * |
| 795 | * [1] Trying to establish a condition handler to trap floating point |
| 796 | * exceptions is not a good idea. */ |
| 797 | |
| 798 | /* In UNICOS and in certain Cray models (such as T90) there is no |
| 799 | * IEEE fp, and no way at all from C to catch fp overflows gracefully. |
| 800 | * There is something you can do if you are willing to use some |
| 801 | * inline assembler: the instruction is called DFI-- but that will |
| 802 | * disable *all* floating point interrupts, a little bit too large |
| 803 | * a hammer. Therefore we need to catch potential overflows before |
| 804 | * it's too late. */ |
| 805 | |
| 806 | #if ((defined(VMS) && !defined(_IEEE_FP)) || defined(_UNICOS)) && defined(NV_MAX_10_EXP) |
| 807 | STMT_START { |
| 808 | const NV exp_v = log10(value); |
| 809 | if (exponent >= NV_MAX_10_EXP || exponent + exp_v >= NV_MAX_10_EXP) |
| 810 | return NV_MAX; |
| 811 | if (exponent < 0) { |
| 812 | if (-(exponent + exp_v) >= NV_MAX_10_EXP) |
| 813 | return 0.0; |
| 814 | while (-exponent >= NV_MAX_10_EXP) { |
| 815 | /* combination does not overflow, but 10^(-exponent) does */ |
| 816 | value /= 10; |
| 817 | ++exponent; |
| 818 | } |
| 819 | } |
| 820 | } STMT_END; |
| 821 | #endif |
| 822 | |
| 823 | if (exponent < 0) { |
| 824 | negative = 1; |
| 825 | exponent = -exponent; |
| 826 | } |
| 827 | for (bit = 1; exponent; bit <<= 1) { |
| 828 | if (exponent & bit) { |
| 829 | exponent ^= bit; |
| 830 | result *= power; |
| 831 | /* Floating point exceptions are supposed to be turned off, |
| 832 | * but if we're obviously done, don't risk another iteration. |
| 833 | */ |
| 834 | if (exponent == 0) break; |
| 835 | } |
| 836 | power *= power; |
| 837 | } |
| 838 | return negative ? value / result : value * result; |
| 839 | } |
| 840 | |
| 841 | NV |
| 842 | Perl_my_atof(pTHX_ const char* s) |
| 843 | { |
| 844 | NV x = 0.0; |
| 845 | #ifdef USE_LOCALE_NUMERIC |
| 846 | dVAR; |
| 847 | |
| 848 | PERL_ARGS_ASSERT_MY_ATOF; |
| 849 | |
| 850 | if (PL_numeric_local && PL_numeric_radix_sv && IN_SOME_LOCALE_FORM) { |
| 851 | const char *standard = NULL, *local = NULL; |
| 852 | bool use_standard_radix; |
| 853 | |
| 854 | /* Look through the string for the first thing that looks like a |
| 855 | * decimal point: either the value in the current locale or the |
| 856 | * standard fallback of '.'. The one which appears earliest in the |
| 857 | * input string is the one that we should have atof look for. Note that |
| 858 | * we have to determine this beforehand because on some systems, |
| 859 | * Perl_atof2 is just a wrapper around the system's atof. */ |
| 860 | standard = strchr(s, '.'); |
| 861 | local = strstr(s, SvPV_nolen(PL_numeric_radix_sv)); |
| 862 | |
| 863 | use_standard_radix = standard && (!local || standard < local); |
| 864 | |
| 865 | if (use_standard_radix) |
| 866 | SET_NUMERIC_STANDARD(); |
| 867 | |
| 868 | Perl_atof2(s, x); |
| 869 | |
| 870 | if (use_standard_radix) |
| 871 | SET_NUMERIC_LOCAL(); |
| 872 | } |
| 873 | else |
| 874 | Perl_atof2(s, x); |
| 875 | #else |
| 876 | Perl_atof2(s, x); |
| 877 | #endif |
| 878 | return x; |
| 879 | } |
| 880 | |
| 881 | char* |
| 882 | Perl_my_atof2(pTHX_ const char* orig, NV* value) |
| 883 | { |
| 884 | NV result[3] = {0.0, 0.0, 0.0}; |
| 885 | const char* s = orig; |
| 886 | #ifdef USE_PERL_ATOF |
| 887 | UV accumulator[2] = {0,0}; /* before/after dp */ |
| 888 | bool negative = 0; |
| 889 | const char* send = s + strlen(orig) - 1; |
| 890 | bool seen_digit = 0; |
| 891 | I32 exp_adjust[2] = {0,0}; |
| 892 | I32 exp_acc[2] = {-1, -1}; |
| 893 | /* the current exponent adjust for the accumulators */ |
| 894 | I32 exponent = 0; |
| 895 | I32 seen_dp = 0; |
| 896 | I32 digit = 0; |
| 897 | I32 old_digit = 0; |
| 898 | I32 sig_digits = 0; /* noof significant digits seen so far */ |
| 899 | |
| 900 | PERL_ARGS_ASSERT_MY_ATOF2; |
| 901 | |
| 902 | /* There is no point in processing more significant digits |
| 903 | * than the NV can hold. Note that NV_DIG is a lower-bound value, |
| 904 | * while we need an upper-bound value. We add 2 to account for this; |
| 905 | * since it will have been conservative on both the first and last digit. |
| 906 | * For example a 32-bit mantissa with an exponent of 4 would have |
| 907 | * exact values in the set |
| 908 | * 4 |
| 909 | * 8 |
| 910 | * .. |
| 911 | * 17179869172 |
| 912 | * 17179869176 |
| 913 | * 17179869180 |
| 914 | * |
| 915 | * where for the purposes of calculating NV_DIG we would have to discount |
| 916 | * both the first and last digit, since neither can hold all values from |
| 917 | * 0..9; but for calculating the value we must examine those two digits. |
| 918 | */ |
| 919 | #ifdef MAX_SIG_DIG_PLUS |
| 920 | /* It is not necessarily the case that adding 2 to NV_DIG gets all the |
| 921 | possible digits in a NV, especially if NVs are not IEEE compliant |
| 922 | (e.g., long doubles on IRIX) - Allen <allens@cpan.org> */ |
| 923 | # define MAX_SIG_DIGITS (NV_DIG+MAX_SIG_DIG_PLUS) |
| 924 | #else |
| 925 | # define MAX_SIG_DIGITS (NV_DIG+2) |
| 926 | #endif |
| 927 | |
| 928 | /* the max number we can accumulate in a UV, and still safely do 10*N+9 */ |
| 929 | #define MAX_ACCUMULATE ( (UV) ((UV_MAX - 9)/10)) |
| 930 | |
| 931 | /* leading whitespace */ |
| 932 | while (isSPACE(*s)) |
| 933 | ++s; |
| 934 | |
| 935 | /* sign */ |
| 936 | switch (*s) { |
| 937 | case '-': |
| 938 | negative = 1; |
| 939 | /* fall through */ |
| 940 | case '+': |
| 941 | ++s; |
| 942 | } |
| 943 | |
| 944 | /* punt to strtod for NaN/Inf; if no support for it there, tough luck */ |
| 945 | |
| 946 | #ifdef HAS_STRTOD |
| 947 | if (*s == 'n' || *s == 'N' || *s == 'i' || *s == 'I') { |
| 948 | const char *p = negative ? s - 1 : s; |
| 949 | char *endp; |
| 950 | NV rslt; |
| 951 | rslt = strtod(p, &endp); |
| 952 | if (endp != p) { |
| 953 | *value = rslt; |
| 954 | return (char *)endp; |
| 955 | } |
| 956 | } |
| 957 | #endif |
| 958 | |
| 959 | /* we accumulate digits into an integer; when this becomes too |
| 960 | * large, we add the total to NV and start again */ |
| 961 | |
| 962 | while (1) { |
| 963 | if (isDIGIT(*s)) { |
| 964 | seen_digit = 1; |
| 965 | old_digit = digit; |
| 966 | digit = *s++ - '0'; |
| 967 | if (seen_dp) |
| 968 | exp_adjust[1]++; |
| 969 | |
| 970 | /* don't start counting until we see the first significant |
| 971 | * digit, eg the 5 in 0.00005... */ |
| 972 | if (!sig_digits && digit == 0) |
| 973 | continue; |
| 974 | |
| 975 | if (++sig_digits > MAX_SIG_DIGITS) { |
| 976 | /* limits of precision reached */ |
| 977 | if (digit > 5) { |
| 978 | ++accumulator[seen_dp]; |
| 979 | } else if (digit == 5) { |
| 980 | if (old_digit % 2) { /* round to even - Allen */ |
| 981 | ++accumulator[seen_dp]; |
| 982 | } |
| 983 | } |
| 984 | if (seen_dp) { |
| 985 | exp_adjust[1]--; |
| 986 | } else { |
| 987 | exp_adjust[0]++; |
| 988 | } |
| 989 | /* skip remaining digits */ |
| 990 | while (isDIGIT(*s)) { |
| 991 | ++s; |
| 992 | if (! seen_dp) { |
| 993 | exp_adjust[0]++; |
| 994 | } |
| 995 | } |
| 996 | /* warn of loss of precision? */ |
| 997 | } |
| 998 | else { |
| 999 | if (accumulator[seen_dp] > MAX_ACCUMULATE) { |
| 1000 | /* add accumulator to result and start again */ |
| 1001 | result[seen_dp] = S_mulexp10(result[seen_dp], |
| 1002 | exp_acc[seen_dp]) |
| 1003 | + (NV)accumulator[seen_dp]; |
| 1004 | accumulator[seen_dp] = 0; |
| 1005 | exp_acc[seen_dp] = 0; |
| 1006 | } |
| 1007 | accumulator[seen_dp] = accumulator[seen_dp] * 10 + digit; |
| 1008 | ++exp_acc[seen_dp]; |
| 1009 | } |
| 1010 | } |
| 1011 | else if (!seen_dp && GROK_NUMERIC_RADIX(&s, send)) { |
| 1012 | seen_dp = 1; |
| 1013 | if (sig_digits > MAX_SIG_DIGITS) { |
| 1014 | do { |
| 1015 | ++s; |
| 1016 | } while (isDIGIT(*s)); |
| 1017 | break; |
| 1018 | } |
| 1019 | } |
| 1020 | else { |
| 1021 | break; |
| 1022 | } |
| 1023 | } |
| 1024 | |
| 1025 | result[0] = S_mulexp10(result[0], exp_acc[0]) + (NV)accumulator[0]; |
| 1026 | if (seen_dp) { |
| 1027 | result[1] = S_mulexp10(result[1], exp_acc[1]) + (NV)accumulator[1]; |
| 1028 | } |
| 1029 | |
| 1030 | if (seen_digit && (*s == 'e' || *s == 'E')) { |
| 1031 | bool expnegative = 0; |
| 1032 | |
| 1033 | ++s; |
| 1034 | switch (*s) { |
| 1035 | case '-': |
| 1036 | expnegative = 1; |
| 1037 | /* fall through */ |
| 1038 | case '+': |
| 1039 | ++s; |
| 1040 | } |
| 1041 | while (isDIGIT(*s)) |
| 1042 | exponent = exponent * 10 + (*s++ - '0'); |
| 1043 | if (expnegative) |
| 1044 | exponent = -exponent; |
| 1045 | } |
| 1046 | |
| 1047 | |
| 1048 | |
| 1049 | /* now apply the exponent */ |
| 1050 | |
| 1051 | if (seen_dp) { |
| 1052 | result[2] = S_mulexp10(result[0],exponent+exp_adjust[0]) |
| 1053 | + S_mulexp10(result[1],exponent-exp_adjust[1]); |
| 1054 | } else { |
| 1055 | result[2] = S_mulexp10(result[0],exponent+exp_adjust[0]); |
| 1056 | } |
| 1057 | |
| 1058 | /* now apply the sign */ |
| 1059 | if (negative) |
| 1060 | result[2] = -result[2]; |
| 1061 | #endif /* USE_PERL_ATOF */ |
| 1062 | *value = result[2]; |
| 1063 | return (char *)s; |
| 1064 | } |
| 1065 | |
| 1066 | #if ! defined(HAS_MODFL) && defined(HAS_AINTL) && defined(HAS_COPYSIGNL) |
| 1067 | long double |
| 1068 | Perl_my_modfl(long double x, long double *ip) |
| 1069 | { |
| 1070 | *ip = aintl(x); |
| 1071 | return (x == *ip ? copysignl(0.0L, x) : x - *ip); |
| 1072 | } |
| 1073 | #endif |
| 1074 | |
| 1075 | #if ! defined(HAS_FREXPL) && defined(HAS_ILOGBL) && defined(HAS_SCALBNL) |
| 1076 | long double |
| 1077 | Perl_my_frexpl(long double x, int *e) { |
| 1078 | *e = x == 0.0L ? 0 : ilogbl(x) + 1; |
| 1079 | return (scalbnl(x, -*e)); |
| 1080 | } |
| 1081 | #endif |
| 1082 | |
| 1083 | /* |
| 1084 | =for apidoc Perl_signbit |
| 1085 | |
| 1086 | Return a non-zero integer if the sign bit on an NV is set, and 0 if |
| 1087 | it is not. |
| 1088 | |
| 1089 | If Configure detects this system has a signbit() that will work with |
| 1090 | our NVs, then we just use it via the #define in perl.h. Otherwise, |
| 1091 | fall back on this implementation. As a first pass, this gets everything |
| 1092 | right except -0.0. Alas, catching -0.0 is the main use for this function, |
| 1093 | so this is not too helpful yet. Still, at least we have the scaffolding |
| 1094 | in place to support other systems, should that prove useful. |
| 1095 | |
| 1096 | |
| 1097 | Configure notes: This function is called 'Perl_signbit' instead of a |
| 1098 | plain 'signbit' because it is easy to imagine a system having a signbit() |
| 1099 | function or macro that doesn't happen to work with our particular choice |
| 1100 | of NVs. We shouldn't just re-#define signbit as Perl_signbit and expect |
| 1101 | the standard system headers to be happy. Also, this is a no-context |
| 1102 | function (no pTHX_) because Perl_signbit() is usually re-#defined in |
| 1103 | perl.h as a simple macro call to the system's signbit(). |
| 1104 | Users should just always call Perl_signbit(). |
| 1105 | |
| 1106 | =cut |
| 1107 | */ |
| 1108 | #if !defined(HAS_SIGNBIT) |
| 1109 | int |
| 1110 | Perl_signbit(NV x) { |
| 1111 | return (x < 0.0) ? 1 : 0; |
| 1112 | } |
| 1113 | #endif |
| 1114 | |
| 1115 | /* |
| 1116 | * Local variables: |
| 1117 | * c-indentation-style: bsd |
| 1118 | * c-basic-offset: 4 |
| 1119 | * indent-tabs-mode: nil |
| 1120 | * End: |
| 1121 | * |
| 1122 | * ex: set ts=8 sts=4 sw=4 et: |
| 1123 | */ |