| 1 | /* Floating point routines for GDB, the GNU debugger. |
| 2 | |
| 3 | Copyright (C) 2017-2020 Free Software Foundation, Inc. |
| 4 | |
| 5 | This file is part of GDB. |
| 6 | |
| 7 | This program is free software; you can redistribute it and/or modify |
| 8 | it under the terms of the GNU General Public License as published by |
| 9 | the Free Software Foundation; either version 3 of the License, or |
| 10 | (at your option) any later version. |
| 11 | |
| 12 | This program is distributed in the hope that it will be useful, |
| 13 | but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 14 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| 15 | GNU General Public License for more details. |
| 16 | |
| 17 | You should have received a copy of the GNU General Public License |
| 18 | along with this program. If not, see <http://www.gnu.org/licenses/>. */ |
| 19 | |
| 20 | #include "defs.h" |
| 21 | #include "gdbtypes.h" |
| 22 | #include "floatformat.h" |
| 23 | #include "target-float.h" |
| 24 | #include "gdbarch.h" |
| 25 | |
| 26 | /* Target floating-point operations. |
| 27 | |
| 28 | We provide multiple implementations of those operations, which differ |
| 29 | by the host-side intermediate format they perform computations in. |
| 30 | |
| 31 | Those multiple implementations all derive from the following abstract |
| 32 | base class, which specifies the set of operations to be implemented. */ |
| 33 | |
| 34 | class target_float_ops |
| 35 | { |
| 36 | public: |
| 37 | virtual std::string to_string (const gdb_byte *addr, const struct type *type, |
| 38 | const char *format) const = 0; |
| 39 | virtual bool from_string (gdb_byte *addr, const struct type *type, |
| 40 | const std::string &string) const = 0; |
| 41 | |
| 42 | virtual LONGEST to_longest (const gdb_byte *addr, |
| 43 | const struct type *type) const = 0; |
| 44 | virtual void from_longest (gdb_byte *addr, const struct type *type, |
| 45 | LONGEST val) const = 0; |
| 46 | virtual void from_ulongest (gdb_byte *addr, const struct type *type, |
| 47 | ULONGEST val) const = 0; |
| 48 | virtual double to_host_double (const gdb_byte *addr, |
| 49 | const struct type *type) const = 0; |
| 50 | virtual void from_host_double (gdb_byte *addr, const struct type *type, |
| 51 | double val) const = 0; |
| 52 | virtual void convert (const gdb_byte *from, const struct type *from_type, |
| 53 | gdb_byte *to, const struct type *to_type) const = 0; |
| 54 | |
| 55 | virtual void binop (enum exp_opcode opcode, |
| 56 | const gdb_byte *x, const struct type *type_x, |
| 57 | const gdb_byte *y, const struct type *type_y, |
| 58 | gdb_byte *res, const struct type *type_res) const = 0; |
| 59 | virtual int compare (const gdb_byte *x, const struct type *type_x, |
| 60 | const gdb_byte *y, const struct type *type_y) const = 0; |
| 61 | }; |
| 62 | |
| 63 | |
| 64 | /* Helper routines operating on binary floating-point data. */ |
| 65 | |
| 66 | #include <cmath> |
| 67 | #include <limits> |
| 68 | |
| 69 | /* Different kinds of floatformat numbers recognized by |
| 70 | floatformat_classify. To avoid portability issues, we use local |
| 71 | values instead of the C99 macros (FP_NAN et cetera). */ |
| 72 | enum float_kind { |
| 73 | float_nan, |
| 74 | float_infinite, |
| 75 | float_zero, |
| 76 | float_normal, |
| 77 | float_subnormal |
| 78 | }; |
| 79 | |
| 80 | /* The odds that CHAR_BIT will be anything but 8 are low enough that I'm not |
| 81 | going to bother with trying to muck around with whether it is defined in |
| 82 | a system header, what we do if not, etc. */ |
| 83 | #define FLOATFORMAT_CHAR_BIT 8 |
| 84 | |
| 85 | /* The number of bytes that the largest floating-point type that we |
| 86 | can convert to doublest will need. */ |
| 87 | #define FLOATFORMAT_LARGEST_BYTES 16 |
| 88 | |
| 89 | /* Return the floatformat's total size in host bytes. */ |
| 90 | static size_t |
| 91 | floatformat_totalsize_bytes (const struct floatformat *fmt) |
| 92 | { |
| 93 | return ((fmt->totalsize + FLOATFORMAT_CHAR_BIT - 1) |
| 94 | / FLOATFORMAT_CHAR_BIT); |
| 95 | } |
| 96 | |
| 97 | /* Return the precision of the floating point format FMT. */ |
| 98 | static int |
| 99 | floatformat_precision (const struct floatformat *fmt) |
| 100 | { |
| 101 | /* Assume the precision of and IBM long double is twice the precision |
| 102 | of the underlying double. This matches what GCC does. */ |
| 103 | if (fmt->split_half) |
| 104 | return 2 * floatformat_precision (fmt->split_half); |
| 105 | |
| 106 | /* Otherwise, the precision is the size of mantissa in bits, |
| 107 | including the implicit bit if present. */ |
| 108 | int prec = fmt->man_len; |
| 109 | if (fmt->intbit == floatformat_intbit_no) |
| 110 | prec++; |
| 111 | |
| 112 | return prec; |
| 113 | } |
| 114 | |
| 115 | /* Normalize the byte order of FROM into TO. If no normalization is |
| 116 | needed then FMT->byteorder is returned and TO is not changed; |
| 117 | otherwise the format of the normalized form in TO is returned. */ |
| 118 | static enum floatformat_byteorders |
| 119 | floatformat_normalize_byteorder (const struct floatformat *fmt, |
| 120 | const void *from, void *to) |
| 121 | { |
| 122 | const unsigned char *swapin; |
| 123 | unsigned char *swapout; |
| 124 | int words; |
| 125 | |
| 126 | if (fmt->byteorder == floatformat_little |
| 127 | || fmt->byteorder == floatformat_big) |
| 128 | return fmt->byteorder; |
| 129 | |
| 130 | words = fmt->totalsize / FLOATFORMAT_CHAR_BIT; |
| 131 | words >>= 2; |
| 132 | |
| 133 | swapout = (unsigned char *)to; |
| 134 | swapin = (const unsigned char *)from; |
| 135 | |
| 136 | if (fmt->byteorder == floatformat_vax) |
| 137 | { |
| 138 | while (words-- > 0) |
| 139 | { |
| 140 | *swapout++ = swapin[1]; |
| 141 | *swapout++ = swapin[0]; |
| 142 | *swapout++ = swapin[3]; |
| 143 | *swapout++ = swapin[2]; |
| 144 | swapin += 4; |
| 145 | } |
| 146 | /* This may look weird, since VAX is little-endian, but it is |
| 147 | easier to translate to big-endian than to little-endian. */ |
| 148 | return floatformat_big; |
| 149 | } |
| 150 | else |
| 151 | { |
| 152 | gdb_assert (fmt->byteorder == floatformat_littlebyte_bigword); |
| 153 | |
| 154 | while (words-- > 0) |
| 155 | { |
| 156 | *swapout++ = swapin[3]; |
| 157 | *swapout++ = swapin[2]; |
| 158 | *swapout++ = swapin[1]; |
| 159 | *swapout++ = swapin[0]; |
| 160 | swapin += 4; |
| 161 | } |
| 162 | return floatformat_big; |
| 163 | } |
| 164 | } |
| 165 | |
| 166 | /* Extract a field which starts at START and is LEN bytes long. DATA and |
| 167 | TOTAL_LEN are the thing we are extracting it from, in byteorder ORDER. */ |
| 168 | static unsigned long |
| 169 | get_field (const bfd_byte *data, enum floatformat_byteorders order, |
| 170 | unsigned int total_len, unsigned int start, unsigned int len) |
| 171 | { |
| 172 | unsigned long result; |
| 173 | unsigned int cur_byte; |
| 174 | int cur_bitshift; |
| 175 | |
| 176 | /* Caller must byte-swap words before calling this routine. */ |
| 177 | gdb_assert (order == floatformat_little || order == floatformat_big); |
| 178 | |
| 179 | /* Start at the least significant part of the field. */ |
| 180 | if (order == floatformat_little) |
| 181 | { |
| 182 | /* We start counting from the other end (i.e, from the high bytes |
| 183 | rather than the low bytes). As such, we need to be concerned |
| 184 | with what happens if bit 0 doesn't start on a byte boundary. |
| 185 | I.e, we need to properly handle the case where total_len is |
| 186 | not evenly divisible by 8. So we compute ``excess'' which |
| 187 | represents the number of bits from the end of our starting |
| 188 | byte needed to get to bit 0. */ |
| 189 | int excess = FLOATFORMAT_CHAR_BIT - (total_len % FLOATFORMAT_CHAR_BIT); |
| 190 | |
| 191 | cur_byte = (total_len / FLOATFORMAT_CHAR_BIT) |
| 192 | - ((start + len + excess) / FLOATFORMAT_CHAR_BIT); |
| 193 | cur_bitshift = ((start + len + excess) % FLOATFORMAT_CHAR_BIT) |
| 194 | - FLOATFORMAT_CHAR_BIT; |
| 195 | } |
| 196 | else |
| 197 | { |
| 198 | cur_byte = (start + len) / FLOATFORMAT_CHAR_BIT; |
| 199 | cur_bitshift = |
| 200 | ((start + len) % FLOATFORMAT_CHAR_BIT) - FLOATFORMAT_CHAR_BIT; |
| 201 | } |
| 202 | if (cur_bitshift > -FLOATFORMAT_CHAR_BIT) |
| 203 | result = *(data + cur_byte) >> (-cur_bitshift); |
| 204 | else |
| 205 | result = 0; |
| 206 | cur_bitshift += FLOATFORMAT_CHAR_BIT; |
| 207 | if (order == floatformat_little) |
| 208 | ++cur_byte; |
| 209 | else |
| 210 | --cur_byte; |
| 211 | |
| 212 | /* Move towards the most significant part of the field. */ |
| 213 | while (cur_bitshift < len) |
| 214 | { |
| 215 | result |= (unsigned long)*(data + cur_byte) << cur_bitshift; |
| 216 | cur_bitshift += FLOATFORMAT_CHAR_BIT; |
| 217 | switch (order) |
| 218 | { |
| 219 | case floatformat_little: |
| 220 | ++cur_byte; |
| 221 | break; |
| 222 | case floatformat_big: |
| 223 | --cur_byte; |
| 224 | break; |
| 225 | } |
| 226 | } |
| 227 | if (len < sizeof(result) * FLOATFORMAT_CHAR_BIT) |
| 228 | /* Mask out bits which are not part of the field. */ |
| 229 | result &= ((1UL << len) - 1); |
| 230 | return result; |
| 231 | } |
| 232 | |
| 233 | /* Set a field which starts at START and is LEN bytes long. DATA and |
| 234 | TOTAL_LEN are the thing we are extracting it from, in byteorder ORDER. */ |
| 235 | static void |
| 236 | put_field (unsigned char *data, enum floatformat_byteorders order, |
| 237 | unsigned int total_len, unsigned int start, unsigned int len, |
| 238 | unsigned long stuff_to_put) |
| 239 | { |
| 240 | unsigned int cur_byte; |
| 241 | int cur_bitshift; |
| 242 | |
| 243 | /* Caller must byte-swap words before calling this routine. */ |
| 244 | gdb_assert (order == floatformat_little || order == floatformat_big); |
| 245 | |
| 246 | /* Start at the least significant part of the field. */ |
| 247 | if (order == floatformat_little) |
| 248 | { |
| 249 | int excess = FLOATFORMAT_CHAR_BIT - (total_len % FLOATFORMAT_CHAR_BIT); |
| 250 | |
| 251 | cur_byte = (total_len / FLOATFORMAT_CHAR_BIT) |
| 252 | - ((start + len + excess) / FLOATFORMAT_CHAR_BIT); |
| 253 | cur_bitshift = ((start + len + excess) % FLOATFORMAT_CHAR_BIT) |
| 254 | - FLOATFORMAT_CHAR_BIT; |
| 255 | } |
| 256 | else |
| 257 | { |
| 258 | cur_byte = (start + len) / FLOATFORMAT_CHAR_BIT; |
| 259 | cur_bitshift = |
| 260 | ((start + len) % FLOATFORMAT_CHAR_BIT) - FLOATFORMAT_CHAR_BIT; |
| 261 | } |
| 262 | if (cur_bitshift > -FLOATFORMAT_CHAR_BIT) |
| 263 | { |
| 264 | *(data + cur_byte) &= |
| 265 | ~(((1 << ((start + len) % FLOATFORMAT_CHAR_BIT)) - 1) |
| 266 | << (-cur_bitshift)); |
| 267 | *(data + cur_byte) |= |
| 268 | (stuff_to_put & ((1 << FLOATFORMAT_CHAR_BIT) - 1)) << (-cur_bitshift); |
| 269 | } |
| 270 | cur_bitshift += FLOATFORMAT_CHAR_BIT; |
| 271 | if (order == floatformat_little) |
| 272 | ++cur_byte; |
| 273 | else |
| 274 | --cur_byte; |
| 275 | |
| 276 | /* Move towards the most significant part of the field. */ |
| 277 | while (cur_bitshift < len) |
| 278 | { |
| 279 | if (len - cur_bitshift < FLOATFORMAT_CHAR_BIT) |
| 280 | { |
| 281 | /* This is the last byte. */ |
| 282 | *(data + cur_byte) &= |
| 283 | ~((1 << (len - cur_bitshift)) - 1); |
| 284 | *(data + cur_byte) |= (stuff_to_put >> cur_bitshift); |
| 285 | } |
| 286 | else |
| 287 | *(data + cur_byte) = ((stuff_to_put >> cur_bitshift) |
| 288 | & ((1 << FLOATFORMAT_CHAR_BIT) - 1)); |
| 289 | cur_bitshift += FLOATFORMAT_CHAR_BIT; |
| 290 | if (order == floatformat_little) |
| 291 | ++cur_byte; |
| 292 | else |
| 293 | --cur_byte; |
| 294 | } |
| 295 | } |
| 296 | |
| 297 | /* Check if VAL (which is assumed to be a floating point number whose |
| 298 | format is described by FMT) is negative. */ |
| 299 | static int |
| 300 | floatformat_is_negative (const struct floatformat *fmt, |
| 301 | const bfd_byte *uval) |
| 302 | { |
| 303 | enum floatformat_byteorders order; |
| 304 | unsigned char newfrom[FLOATFORMAT_LARGEST_BYTES]; |
| 305 | |
| 306 | gdb_assert (fmt != NULL); |
| 307 | gdb_assert (fmt->totalsize |
| 308 | <= FLOATFORMAT_LARGEST_BYTES * FLOATFORMAT_CHAR_BIT); |
| 309 | |
| 310 | /* An IBM long double (a two element array of double) always takes the |
| 311 | sign of the first double. */ |
| 312 | if (fmt->split_half) |
| 313 | fmt = fmt->split_half; |
| 314 | |
| 315 | order = floatformat_normalize_byteorder (fmt, uval, newfrom); |
| 316 | |
| 317 | if (order != fmt->byteorder) |
| 318 | uval = newfrom; |
| 319 | |
| 320 | return get_field (uval, order, fmt->totalsize, fmt->sign_start, 1); |
| 321 | } |
| 322 | |
| 323 | /* Check if VAL is "not a number" (NaN) for FMT. */ |
| 324 | static enum float_kind |
| 325 | floatformat_classify (const struct floatformat *fmt, |
| 326 | const bfd_byte *uval) |
| 327 | { |
| 328 | long exponent; |
| 329 | unsigned long mant; |
| 330 | unsigned int mant_bits, mant_off; |
| 331 | int mant_bits_left; |
| 332 | enum floatformat_byteorders order; |
| 333 | unsigned char newfrom[FLOATFORMAT_LARGEST_BYTES]; |
| 334 | int mant_zero; |
| 335 | |
| 336 | gdb_assert (fmt != NULL); |
| 337 | gdb_assert (fmt->totalsize |
| 338 | <= FLOATFORMAT_LARGEST_BYTES * FLOATFORMAT_CHAR_BIT); |
| 339 | |
| 340 | /* An IBM long double (a two element array of double) can be classified |
| 341 | by looking at the first double. inf and nan are specified as |
| 342 | ignoring the second double. zero and subnormal will always have |
| 343 | the second double 0.0 if the long double is correctly rounded. */ |
| 344 | if (fmt->split_half) |
| 345 | fmt = fmt->split_half; |
| 346 | |
| 347 | order = floatformat_normalize_byteorder (fmt, uval, newfrom); |
| 348 | |
| 349 | if (order != fmt->byteorder) |
| 350 | uval = newfrom; |
| 351 | |
| 352 | exponent = get_field (uval, order, fmt->totalsize, fmt->exp_start, |
| 353 | fmt->exp_len); |
| 354 | |
| 355 | mant_bits_left = fmt->man_len; |
| 356 | mant_off = fmt->man_start; |
| 357 | |
| 358 | mant_zero = 1; |
| 359 | while (mant_bits_left > 0) |
| 360 | { |
| 361 | mant_bits = std::min (mant_bits_left, 32); |
| 362 | |
| 363 | mant = get_field (uval, order, fmt->totalsize, mant_off, mant_bits); |
| 364 | |
| 365 | /* If there is an explicit integer bit, mask it off. */ |
| 366 | if (mant_off == fmt->man_start |
| 367 | && fmt->intbit == floatformat_intbit_yes) |
| 368 | mant &= ~(1 << (mant_bits - 1)); |
| 369 | |
| 370 | if (mant) |
| 371 | { |
| 372 | mant_zero = 0; |
| 373 | break; |
| 374 | } |
| 375 | |
| 376 | mant_off += mant_bits; |
| 377 | mant_bits_left -= mant_bits; |
| 378 | } |
| 379 | |
| 380 | /* If exp_nan is not set, assume that inf, NaN, and subnormals are not |
| 381 | supported. */ |
| 382 | if (! fmt->exp_nan) |
| 383 | { |
| 384 | if (mant_zero) |
| 385 | return float_zero; |
| 386 | else |
| 387 | return float_normal; |
| 388 | } |
| 389 | |
| 390 | if (exponent == 0) |
| 391 | { |
| 392 | if (mant_zero) |
| 393 | return float_zero; |
| 394 | else |
| 395 | return float_subnormal; |
| 396 | } |
| 397 | |
| 398 | if (exponent == fmt->exp_nan) |
| 399 | { |
| 400 | if (mant_zero) |
| 401 | return float_infinite; |
| 402 | else |
| 403 | return float_nan; |
| 404 | } |
| 405 | |
| 406 | return float_normal; |
| 407 | } |
| 408 | |
| 409 | /* Convert the mantissa of VAL (which is assumed to be a floating |
| 410 | point number whose format is described by FMT) into a hexadecimal |
| 411 | and store it in a static string. Return a pointer to that string. */ |
| 412 | static const char * |
| 413 | floatformat_mantissa (const struct floatformat *fmt, |
| 414 | const bfd_byte *val) |
| 415 | { |
| 416 | unsigned char *uval = (unsigned char *) val; |
| 417 | unsigned long mant; |
| 418 | unsigned int mant_bits, mant_off; |
| 419 | int mant_bits_left; |
| 420 | static char res[50]; |
| 421 | char buf[9]; |
| 422 | int len; |
| 423 | enum floatformat_byteorders order; |
| 424 | unsigned char newfrom[FLOATFORMAT_LARGEST_BYTES]; |
| 425 | |
| 426 | gdb_assert (fmt != NULL); |
| 427 | gdb_assert (fmt->totalsize |
| 428 | <= FLOATFORMAT_LARGEST_BYTES * FLOATFORMAT_CHAR_BIT); |
| 429 | |
| 430 | /* For IBM long double (a two element array of double), return the |
| 431 | mantissa of the first double. The problem with returning the |
| 432 | actual mantissa from both doubles is that there can be an |
| 433 | arbitrary number of implied 0's or 1's between the mantissas |
| 434 | of the first and second double. In any case, this function |
| 435 | is only used for dumping out nans, and a nan is specified to |
| 436 | ignore the value in the second double. */ |
| 437 | if (fmt->split_half) |
| 438 | fmt = fmt->split_half; |
| 439 | |
| 440 | order = floatformat_normalize_byteorder (fmt, uval, newfrom); |
| 441 | |
| 442 | if (order != fmt->byteorder) |
| 443 | uval = newfrom; |
| 444 | |
| 445 | if (! fmt->exp_nan) |
| 446 | return 0; |
| 447 | |
| 448 | /* Make sure we have enough room to store the mantissa. */ |
| 449 | gdb_assert (sizeof res > ((fmt->man_len + 7) / 8) * 2); |
| 450 | |
| 451 | mant_off = fmt->man_start; |
| 452 | mant_bits_left = fmt->man_len; |
| 453 | mant_bits = (mant_bits_left % 32) > 0 ? mant_bits_left % 32 : 32; |
| 454 | |
| 455 | mant = get_field (uval, order, fmt->totalsize, mant_off, mant_bits); |
| 456 | |
| 457 | len = xsnprintf (res, sizeof res, "%lx", mant); |
| 458 | |
| 459 | mant_off += mant_bits; |
| 460 | mant_bits_left -= mant_bits; |
| 461 | |
| 462 | while (mant_bits_left > 0) |
| 463 | { |
| 464 | mant = get_field (uval, order, fmt->totalsize, mant_off, 32); |
| 465 | |
| 466 | xsnprintf (buf, sizeof buf, "%08lx", mant); |
| 467 | gdb_assert (len + strlen (buf) <= sizeof res); |
| 468 | strcat (res, buf); |
| 469 | |
| 470 | mant_off += 32; |
| 471 | mant_bits_left -= 32; |
| 472 | } |
| 473 | |
| 474 | return res; |
| 475 | } |
| 476 | |
| 477 | /* Convert printf format string FORMAT to the otherwise equivalent string |
| 478 | which may be used to print a host floating-point number using the length |
| 479 | modifier LENGTH (which may be 0 if none is needed). If FORMAT is null, |
| 480 | return a format appropriate to print the full precision of a target |
| 481 | floating-point number of format FMT. */ |
| 482 | static std::string |
| 483 | floatformat_printf_format (const struct floatformat *fmt, |
| 484 | const char *format, char length) |
| 485 | { |
| 486 | std::string host_format; |
| 487 | char conversion; |
| 488 | |
| 489 | if (format == nullptr) |
| 490 | { |
| 491 | /* If no format was specified, print the number using a format string |
| 492 | where the precision is set to the DECIMAL_DIG value for the given |
| 493 | floating-point format. This value is computed as |
| 494 | |
| 495 | ceil(1 + p * log10(b)), |
| 496 | |
| 497 | where p is the precision of the floating-point format in bits, and |
| 498 | b is the base (which is always 2 for the formats we support). */ |
| 499 | const double log10_2 = .30102999566398119521; |
| 500 | double d_decimal_dig = 1 + floatformat_precision (fmt) * log10_2; |
| 501 | int decimal_dig = d_decimal_dig; |
| 502 | if (decimal_dig < d_decimal_dig) |
| 503 | decimal_dig++; |
| 504 | |
| 505 | host_format = string_printf ("%%.%d", decimal_dig); |
| 506 | conversion = 'g'; |
| 507 | } |
| 508 | else |
| 509 | { |
| 510 | /* Use the specified format, stripping out the conversion character |
| 511 | and length modifier, if present. */ |
| 512 | size_t len = strlen (format); |
| 513 | gdb_assert (len > 1); |
| 514 | conversion = format[--len]; |
| 515 | gdb_assert (conversion == 'e' || conversion == 'f' || conversion == 'g' |
| 516 | || conversion == 'E' || conversion == 'G'); |
| 517 | if (format[len - 1] == 'L') |
| 518 | len--; |
| 519 | |
| 520 | host_format = std::string (format, len); |
| 521 | } |
| 522 | |
| 523 | /* Add the length modifier and conversion character appropriate for |
| 524 | handling the appropriate host floating-point type. */ |
| 525 | if (length) |
| 526 | host_format += length; |
| 527 | host_format += conversion; |
| 528 | |
| 529 | return host_format; |
| 530 | } |
| 531 | |
| 532 | /* Implementation of target_float_ops using the host floating-point type T |
| 533 | as intermediate type. */ |
| 534 | |
| 535 | template<typename T> class host_float_ops : public target_float_ops |
| 536 | { |
| 537 | public: |
| 538 | std::string to_string (const gdb_byte *addr, const struct type *type, |
| 539 | const char *format) const override; |
| 540 | bool from_string (gdb_byte *addr, const struct type *type, |
| 541 | const std::string &string) const override; |
| 542 | |
| 543 | LONGEST to_longest (const gdb_byte *addr, |
| 544 | const struct type *type) const override; |
| 545 | void from_longest (gdb_byte *addr, const struct type *type, |
| 546 | LONGEST val) const override; |
| 547 | void from_ulongest (gdb_byte *addr, const struct type *type, |
| 548 | ULONGEST val) const override; |
| 549 | double to_host_double (const gdb_byte *addr, |
| 550 | const struct type *type) const override; |
| 551 | void from_host_double (gdb_byte *addr, const struct type *type, |
| 552 | double val) const override; |
| 553 | void convert (const gdb_byte *from, const struct type *from_type, |
| 554 | gdb_byte *to, const struct type *to_type) const override; |
| 555 | |
| 556 | void binop (enum exp_opcode opcode, |
| 557 | const gdb_byte *x, const struct type *type_x, |
| 558 | const gdb_byte *y, const struct type *type_y, |
| 559 | gdb_byte *res, const struct type *type_res) const override; |
| 560 | int compare (const gdb_byte *x, const struct type *type_x, |
| 561 | const gdb_byte *y, const struct type *type_y) const override; |
| 562 | |
| 563 | private: |
| 564 | void from_target (const struct floatformat *fmt, |
| 565 | const gdb_byte *from, T *to) const; |
| 566 | void from_target (const struct type *type, |
| 567 | const gdb_byte *from, T *to) const; |
| 568 | |
| 569 | void to_target (const struct type *type, |
| 570 | const T *from, gdb_byte *to) const; |
| 571 | void to_target (const struct floatformat *fmt, |
| 572 | const T *from, gdb_byte *to) const; |
| 573 | }; |
| 574 | |
| 575 | |
| 576 | /* Convert TO/FROM target to the host floating-point format T. |
| 577 | |
| 578 | If the host and target formats agree, we just copy the raw data |
| 579 | into the appropriate type of variable and return, letting the host |
| 580 | increase precision as necessary. Otherwise, we call the conversion |
| 581 | routine and let it do the dirty work. Note that even if the target |
| 582 | and host floating-point formats match, the length of the types |
| 583 | might still be different, so the conversion routines must make sure |
| 584 | to not overrun any buffers. For example, on x86, long double is |
| 585 | the 80-bit extended precision type on both 32-bit and 64-bit ABIs, |
| 586 | but by default it is stored as 12 bytes on 32-bit, and 16 bytes on |
| 587 | 64-bit, for alignment reasons. See comment in store_typed_floating |
| 588 | for a discussion about zeroing out remaining bytes in the target |
| 589 | buffer. */ |
| 590 | |
| 591 | static const struct floatformat *host_float_format = GDB_HOST_FLOAT_FORMAT; |
| 592 | static const struct floatformat *host_double_format = GDB_HOST_DOUBLE_FORMAT; |
| 593 | static const struct floatformat *host_long_double_format |
| 594 | = GDB_HOST_LONG_DOUBLE_FORMAT; |
| 595 | |
| 596 | /* Convert target floating-point value at FROM in format FMT to host |
| 597 | floating-point format of type T. */ |
| 598 | template<typename T> void |
| 599 | host_float_ops<T>::from_target (const struct floatformat *fmt, |
| 600 | const gdb_byte *from, T *to) const |
| 601 | { |
| 602 | gdb_assert (fmt != NULL); |
| 603 | |
| 604 | if (fmt == host_float_format) |
| 605 | { |
| 606 | float val = 0; |
| 607 | |
| 608 | memcpy (&val, from, floatformat_totalsize_bytes (fmt)); |
| 609 | *to = val; |
| 610 | return; |
| 611 | } |
| 612 | else if (fmt == host_double_format) |
| 613 | { |
| 614 | double val = 0; |
| 615 | |
| 616 | memcpy (&val, from, floatformat_totalsize_bytes (fmt)); |
| 617 | *to = val; |
| 618 | return; |
| 619 | } |
| 620 | else if (fmt == host_long_double_format) |
| 621 | { |
| 622 | long double val = 0; |
| 623 | |
| 624 | memcpy (&val, from, floatformat_totalsize_bytes (fmt)); |
| 625 | *to = val; |
| 626 | return; |
| 627 | } |
| 628 | |
| 629 | unsigned char *ufrom = (unsigned char *) from; |
| 630 | long exponent; |
| 631 | unsigned long mant; |
| 632 | unsigned int mant_bits, mant_off; |
| 633 | int mant_bits_left; |
| 634 | int special_exponent; /* It's a NaN, denorm or zero. */ |
| 635 | enum floatformat_byteorders order; |
| 636 | unsigned char newfrom[FLOATFORMAT_LARGEST_BYTES]; |
| 637 | enum float_kind kind; |
| 638 | |
| 639 | gdb_assert (fmt->totalsize |
| 640 | <= FLOATFORMAT_LARGEST_BYTES * FLOATFORMAT_CHAR_BIT); |
| 641 | |
| 642 | /* For non-numbers, reuse libiberty's logic to find the correct |
| 643 | format. We do not lose any precision in this case by passing |
| 644 | through a double. */ |
| 645 | kind = floatformat_classify (fmt, (const bfd_byte *) from); |
| 646 | if (kind == float_infinite || kind == float_nan) |
| 647 | { |
| 648 | double dto; |
| 649 | |
| 650 | floatformat_to_double /* ARI: floatformat_to_double */ |
| 651 | (fmt->split_half ? fmt->split_half : fmt, from, &dto); |
| 652 | *to = (T) dto; |
| 653 | return; |
| 654 | } |
| 655 | |
| 656 | order = floatformat_normalize_byteorder (fmt, ufrom, newfrom); |
| 657 | |
| 658 | if (order != fmt->byteorder) |
| 659 | ufrom = newfrom; |
| 660 | |
| 661 | if (fmt->split_half) |
| 662 | { |
| 663 | T dtop, dbot; |
| 664 | |
| 665 | from_target (fmt->split_half, ufrom, &dtop); |
| 666 | /* Preserve the sign of 0, which is the sign of the top |
| 667 | half. */ |
| 668 | if (dtop == 0.0) |
| 669 | { |
| 670 | *to = dtop; |
| 671 | return; |
| 672 | } |
| 673 | from_target (fmt->split_half, |
| 674 | ufrom + fmt->totalsize / FLOATFORMAT_CHAR_BIT / 2, &dbot); |
| 675 | *to = dtop + dbot; |
| 676 | return; |
| 677 | } |
| 678 | |
| 679 | exponent = get_field (ufrom, order, fmt->totalsize, fmt->exp_start, |
| 680 | fmt->exp_len); |
| 681 | /* Note that if exponent indicates a NaN, we can't really do anything useful |
| 682 | (not knowing if the host has NaN's, or how to build one). So it will |
| 683 | end up as an infinity or something close; that is OK. */ |
| 684 | |
| 685 | mant_bits_left = fmt->man_len; |
| 686 | mant_off = fmt->man_start; |
| 687 | T dto = 0.0; |
| 688 | |
| 689 | special_exponent = exponent == 0 || exponent == fmt->exp_nan; |
| 690 | |
| 691 | /* Don't bias NaNs. Use minimum exponent for denorms. For |
| 692 | simplicity, we don't check for zero as the exponent doesn't matter. |
| 693 | Note the cast to int; exp_bias is unsigned, so it's important to |
| 694 | make sure the operation is done in signed arithmetic. */ |
| 695 | if (!special_exponent) |
| 696 | exponent -= fmt->exp_bias; |
| 697 | else if (exponent == 0) |
| 698 | exponent = 1 - fmt->exp_bias; |
| 699 | |
| 700 | /* Build the result algebraically. Might go infinite, underflow, etc; |
| 701 | who cares. */ |
| 702 | |
| 703 | /* If this format uses a hidden bit, explicitly add it in now. Otherwise, |
| 704 | increment the exponent by one to account for the integer bit. */ |
| 705 | |
| 706 | if (!special_exponent) |
| 707 | { |
| 708 | if (fmt->intbit == floatformat_intbit_no) |
| 709 | dto = ldexp (1.0, exponent); |
| 710 | else |
| 711 | exponent++; |
| 712 | } |
| 713 | |
| 714 | while (mant_bits_left > 0) |
| 715 | { |
| 716 | mant_bits = std::min (mant_bits_left, 32); |
| 717 | |
| 718 | mant = get_field (ufrom, order, fmt->totalsize, mant_off, mant_bits); |
| 719 | |
| 720 | dto += ldexp ((T) mant, exponent - mant_bits); |
| 721 | exponent -= mant_bits; |
| 722 | mant_off += mant_bits; |
| 723 | mant_bits_left -= mant_bits; |
| 724 | } |
| 725 | |
| 726 | /* Negate it if negative. */ |
| 727 | if (get_field (ufrom, order, fmt->totalsize, fmt->sign_start, 1)) |
| 728 | dto = -dto; |
| 729 | *to = dto; |
| 730 | } |
| 731 | |
| 732 | template<typename T> void |
| 733 | host_float_ops<T>::from_target (const struct type *type, |
| 734 | const gdb_byte *from, T *to) const |
| 735 | { |
| 736 | from_target (floatformat_from_type (type), from, to); |
| 737 | } |
| 738 | |
| 739 | /* Convert host floating-point value of type T to target floating-point |
| 740 | value in format FMT and store at TO. */ |
| 741 | template<typename T> void |
| 742 | host_float_ops<T>::to_target (const struct floatformat *fmt, |
| 743 | const T *from, gdb_byte *to) const |
| 744 | { |
| 745 | gdb_assert (fmt != NULL); |
| 746 | |
| 747 | if (fmt == host_float_format) |
| 748 | { |
| 749 | float val = *from; |
| 750 | |
| 751 | memcpy (to, &val, floatformat_totalsize_bytes (fmt)); |
| 752 | return; |
| 753 | } |
| 754 | else if (fmt == host_double_format) |
| 755 | { |
| 756 | double val = *from; |
| 757 | |
| 758 | memcpy (to, &val, floatformat_totalsize_bytes (fmt)); |
| 759 | return; |
| 760 | } |
| 761 | else if (fmt == host_long_double_format) |
| 762 | { |
| 763 | long double val = *from; |
| 764 | |
| 765 | memcpy (to, &val, floatformat_totalsize_bytes (fmt)); |
| 766 | return; |
| 767 | } |
| 768 | |
| 769 | T dfrom; |
| 770 | int exponent; |
| 771 | T mant; |
| 772 | unsigned int mant_bits, mant_off; |
| 773 | int mant_bits_left; |
| 774 | unsigned char *uto = (unsigned char *) to; |
| 775 | enum floatformat_byteorders order = fmt->byteorder; |
| 776 | unsigned char newto[FLOATFORMAT_LARGEST_BYTES]; |
| 777 | |
| 778 | if (order != floatformat_little) |
| 779 | order = floatformat_big; |
| 780 | |
| 781 | if (order != fmt->byteorder) |
| 782 | uto = newto; |
| 783 | |
| 784 | memcpy (&dfrom, from, sizeof (dfrom)); |
| 785 | memset (uto, 0, floatformat_totalsize_bytes (fmt)); |
| 786 | |
| 787 | if (fmt->split_half) |
| 788 | { |
| 789 | /* Use static volatile to ensure that any excess precision is |
| 790 | removed via storing in memory, and so the top half really is |
| 791 | the result of converting to double. */ |
| 792 | static volatile double dtop, dbot; |
| 793 | T dtopnv, dbotnv; |
| 794 | |
| 795 | dtop = (double) dfrom; |
| 796 | /* If the rounded top half is Inf, the bottom must be 0 not NaN |
| 797 | or Inf. */ |
| 798 | if (dtop + dtop == dtop && dtop != 0.0) |
| 799 | dbot = 0.0; |
| 800 | else |
| 801 | dbot = (double) (dfrom - (T) dtop); |
| 802 | dtopnv = dtop; |
| 803 | dbotnv = dbot; |
| 804 | to_target (fmt->split_half, &dtopnv, uto); |
| 805 | to_target (fmt->split_half, &dbotnv, |
| 806 | uto + fmt->totalsize / FLOATFORMAT_CHAR_BIT / 2); |
| 807 | return; |
| 808 | } |
| 809 | |
| 810 | if (dfrom == 0) |
| 811 | goto finalize_byteorder; /* Result is zero */ |
| 812 | if (dfrom != dfrom) /* Result is NaN */ |
| 813 | { |
| 814 | /* From is NaN */ |
| 815 | put_field (uto, order, fmt->totalsize, fmt->exp_start, |
| 816 | fmt->exp_len, fmt->exp_nan); |
| 817 | /* Be sure it's not infinity, but NaN value is irrel. */ |
| 818 | put_field (uto, order, fmt->totalsize, fmt->man_start, |
| 819 | fmt->man_len, 1); |
| 820 | goto finalize_byteorder; |
| 821 | } |
| 822 | |
| 823 | /* If negative, set the sign bit. */ |
| 824 | if (dfrom < 0) |
| 825 | { |
| 826 | put_field (uto, order, fmt->totalsize, fmt->sign_start, 1, 1); |
| 827 | dfrom = -dfrom; |
| 828 | } |
| 829 | |
| 830 | if (dfrom + dfrom == dfrom && dfrom != 0.0) /* Result is Infinity. */ |
| 831 | { |
| 832 | /* Infinity exponent is same as NaN's. */ |
| 833 | put_field (uto, order, fmt->totalsize, fmt->exp_start, |
| 834 | fmt->exp_len, fmt->exp_nan); |
| 835 | /* Infinity mantissa is all zeroes. */ |
| 836 | put_field (uto, order, fmt->totalsize, fmt->man_start, |
| 837 | fmt->man_len, 0); |
| 838 | goto finalize_byteorder; |
| 839 | } |
| 840 | |
| 841 | mant = frexp (dfrom, &exponent); |
| 842 | |
| 843 | if (exponent + fmt->exp_bias <= 0) |
| 844 | { |
| 845 | /* The value is too small to be expressed in the destination |
| 846 | type (not enough bits in the exponent. Treat as 0. */ |
| 847 | put_field (uto, order, fmt->totalsize, fmt->exp_start, |
| 848 | fmt->exp_len, 0); |
| 849 | put_field (uto, order, fmt->totalsize, fmt->man_start, |
| 850 | fmt->man_len, 0); |
| 851 | goto finalize_byteorder; |
| 852 | } |
| 853 | |
| 854 | if (exponent + fmt->exp_bias >= (1 << fmt->exp_len)) |
| 855 | { |
| 856 | /* The value is too large to fit into the destination. |
| 857 | Treat as infinity. */ |
| 858 | put_field (uto, order, fmt->totalsize, fmt->exp_start, |
| 859 | fmt->exp_len, fmt->exp_nan); |
| 860 | put_field (uto, order, fmt->totalsize, fmt->man_start, |
| 861 | fmt->man_len, 0); |
| 862 | goto finalize_byteorder; |
| 863 | } |
| 864 | |
| 865 | put_field (uto, order, fmt->totalsize, fmt->exp_start, fmt->exp_len, |
| 866 | exponent + fmt->exp_bias - 1); |
| 867 | |
| 868 | mant_bits_left = fmt->man_len; |
| 869 | mant_off = fmt->man_start; |
| 870 | while (mant_bits_left > 0) |
| 871 | { |
| 872 | unsigned long mant_long; |
| 873 | |
| 874 | mant_bits = mant_bits_left < 32 ? mant_bits_left : 32; |
| 875 | |
| 876 | mant *= 4294967296.0; |
| 877 | mant_long = ((unsigned long) mant) & 0xffffffffL; |
| 878 | mant -= mant_long; |
| 879 | |
| 880 | /* If the integer bit is implicit, then we need to discard it. |
| 881 | If we are discarding a zero, we should be (but are not) creating |
| 882 | a denormalized number which means adjusting the exponent |
| 883 | (I think). */ |
| 884 | if (mant_bits_left == fmt->man_len |
| 885 | && fmt->intbit == floatformat_intbit_no) |
| 886 | { |
| 887 | mant_long <<= 1; |
| 888 | mant_long &= 0xffffffffL; |
| 889 | /* If we are processing the top 32 mantissa bits of a doublest |
| 890 | so as to convert to a float value with implied integer bit, |
| 891 | we will only be putting 31 of those 32 bits into the |
| 892 | final value due to the discarding of the top bit. In the |
| 893 | case of a small float value where the number of mantissa |
| 894 | bits is less than 32, discarding the top bit does not alter |
| 895 | the number of bits we will be adding to the result. */ |
| 896 | if (mant_bits == 32) |
| 897 | mant_bits -= 1; |
| 898 | } |
| 899 | |
| 900 | if (mant_bits < 32) |
| 901 | { |
| 902 | /* The bits we want are in the most significant MANT_BITS bits of |
| 903 | mant_long. Move them to the least significant. */ |
| 904 | mant_long >>= 32 - mant_bits; |
| 905 | } |
| 906 | |
| 907 | put_field (uto, order, fmt->totalsize, |
| 908 | mant_off, mant_bits, mant_long); |
| 909 | mant_off += mant_bits; |
| 910 | mant_bits_left -= mant_bits; |
| 911 | } |
| 912 | |
| 913 | finalize_byteorder: |
| 914 | /* Do we need to byte-swap the words in the result? */ |
| 915 | if (order != fmt->byteorder) |
| 916 | floatformat_normalize_byteorder (fmt, newto, to); |
| 917 | } |
| 918 | |
| 919 | template<typename T> void |
| 920 | host_float_ops<T>::to_target (const struct type *type, |
| 921 | const T *from, gdb_byte *to) const |
| 922 | { |
| 923 | /* Ensure possible padding bytes in the target buffer are zeroed out. */ |
| 924 | memset (to, 0, TYPE_LENGTH (type)); |
| 925 | |
| 926 | to_target (floatformat_from_type (type), from, to); |
| 927 | } |
| 928 | |
| 929 | /* Convert the byte-stream ADDR, interpreted as floating-point type TYPE, |
| 930 | to a string, optionally using the print format FORMAT. */ |
| 931 | template<typename T> struct printf_length_modifier |
| 932 | { |
| 933 | static constexpr char value = 0; |
| 934 | }; |
| 935 | template<> struct printf_length_modifier<long double> |
| 936 | { |
| 937 | static constexpr char value = 'L'; |
| 938 | }; |
| 939 | template<typename T> std::string |
| 940 | host_float_ops<T>::to_string (const gdb_byte *addr, const struct type *type, |
| 941 | const char *format) const |
| 942 | { |
| 943 | /* Determine the format string to use on the host side. */ |
| 944 | constexpr char length = printf_length_modifier<T>::value; |
| 945 | const struct floatformat *fmt = floatformat_from_type (type); |
| 946 | std::string host_format = floatformat_printf_format (fmt, format, length); |
| 947 | |
| 948 | T host_float; |
| 949 | from_target (type, addr, &host_float); |
| 950 | |
| 951 | DIAGNOSTIC_PUSH |
| 952 | DIAGNOSTIC_IGNORE_FORMAT_NONLITERAL |
| 953 | return string_printf (host_format.c_str (), host_float); |
| 954 | DIAGNOSTIC_POP |
| 955 | } |
| 956 | |
| 957 | /* Parse string IN into a target floating-number of type TYPE and |
| 958 | store it as byte-stream ADDR. Return whether parsing succeeded. */ |
| 959 | template<typename T> struct scanf_length_modifier |
| 960 | { |
| 961 | static constexpr char value = 0; |
| 962 | }; |
| 963 | template<> struct scanf_length_modifier<double> |
| 964 | { |
| 965 | static constexpr char value = 'l'; |
| 966 | }; |
| 967 | template<> struct scanf_length_modifier<long double> |
| 968 | { |
| 969 | static constexpr char value = 'L'; |
| 970 | }; |
| 971 | template<typename T> bool |
| 972 | host_float_ops<T>::from_string (gdb_byte *addr, const struct type *type, |
| 973 | const std::string &in) const |
| 974 | { |
| 975 | T host_float; |
| 976 | int n, num; |
| 977 | |
| 978 | std::string scan_format = "%"; |
| 979 | if (scanf_length_modifier<T>::value) |
| 980 | scan_format += scanf_length_modifier<T>::value; |
| 981 | scan_format += "g%n"; |
| 982 | |
| 983 | DIAGNOSTIC_PUSH |
| 984 | DIAGNOSTIC_IGNORE_FORMAT_NONLITERAL |
| 985 | num = sscanf (in.c_str (), scan_format.c_str(), &host_float, &n); |
| 986 | DIAGNOSTIC_POP |
| 987 | |
| 988 | /* The sscanf man page suggests not making any assumptions on the effect |
| 989 | of %n on the result, so we don't. |
| 990 | That is why we simply test num == 0. */ |
| 991 | if (num == 0) |
| 992 | return false; |
| 993 | |
| 994 | /* We only accept the whole string. */ |
| 995 | if (in[n]) |
| 996 | return false; |
| 997 | |
| 998 | to_target (type, &host_float, addr); |
| 999 | return true; |
| 1000 | } |
| 1001 | |
| 1002 | /* Convert the byte-stream ADDR, interpreted as floating-point type TYPE, |
| 1003 | to an integer value (rounding towards zero). */ |
| 1004 | template<typename T> LONGEST |
| 1005 | host_float_ops<T>::to_longest (const gdb_byte *addr, |
| 1006 | const struct type *type) const |
| 1007 | { |
| 1008 | T host_float; |
| 1009 | from_target (type, addr, &host_float); |
| 1010 | T min_possible_range = static_cast<T>(std::numeric_limits<LONGEST>::min()); |
| 1011 | T max_possible_range = -min_possible_range; |
| 1012 | /* host_float can be converted to an integer as long as it's in |
| 1013 | the range [min_possible_range, max_possible_range). If not, it is either |
| 1014 | too large, or too small, or is NaN; in this case return the maximum or |
| 1015 | minimum possible value. */ |
| 1016 | if (host_float < max_possible_range && host_float >= min_possible_range) |
| 1017 | return static_cast<LONGEST> (host_float); |
| 1018 | if (host_float < min_possible_range) |
| 1019 | return std::numeric_limits<LONGEST>::min(); |
| 1020 | /* This line will be executed if host_float is NaN. */ |
| 1021 | return std::numeric_limits<LONGEST>::max(); |
| 1022 | } |
| 1023 | |
| 1024 | /* Convert signed integer VAL to a target floating-number of type TYPE |
| 1025 | and store it as byte-stream ADDR. */ |
| 1026 | template<typename T> void |
| 1027 | host_float_ops<T>::from_longest (gdb_byte *addr, const struct type *type, |
| 1028 | LONGEST val) const |
| 1029 | { |
| 1030 | T host_float = (T) val; |
| 1031 | to_target (type, &host_float, addr); |
| 1032 | } |
| 1033 | |
| 1034 | /* Convert unsigned integer VAL to a target floating-number of type TYPE |
| 1035 | and store it as byte-stream ADDR. */ |
| 1036 | template<typename T> void |
| 1037 | host_float_ops<T>::from_ulongest (gdb_byte *addr, const struct type *type, |
| 1038 | ULONGEST val) const |
| 1039 | { |
| 1040 | T host_float = (T) val; |
| 1041 | to_target (type, &host_float, addr); |
| 1042 | } |
| 1043 | |
| 1044 | /* Convert the byte-stream ADDR, interpreted as floating-point type TYPE, |
| 1045 | to a floating-point value in the host "double" format. */ |
| 1046 | template<typename T> double |
| 1047 | host_float_ops<T>::to_host_double (const gdb_byte *addr, |
| 1048 | const struct type *type) const |
| 1049 | { |
| 1050 | T host_float; |
| 1051 | from_target (type, addr, &host_float); |
| 1052 | return (double) host_float; |
| 1053 | } |
| 1054 | |
| 1055 | /* Convert floating-point value VAL in the host "double" format to a target |
| 1056 | floating-number of type TYPE and store it as byte-stream ADDR. */ |
| 1057 | template<typename T> void |
| 1058 | host_float_ops<T>::from_host_double (gdb_byte *addr, const struct type *type, |
| 1059 | double val) const |
| 1060 | { |
| 1061 | T host_float = (T) val; |
| 1062 | to_target (type, &host_float, addr); |
| 1063 | } |
| 1064 | |
| 1065 | /* Convert a floating-point number of type FROM_TYPE from the target |
| 1066 | byte-stream FROM to a floating-point number of type TO_TYPE, and |
| 1067 | store it to the target byte-stream TO. */ |
| 1068 | template<typename T> void |
| 1069 | host_float_ops<T>::convert (const gdb_byte *from, |
| 1070 | const struct type *from_type, |
| 1071 | gdb_byte *to, |
| 1072 | const struct type *to_type) const |
| 1073 | { |
| 1074 | T host_float; |
| 1075 | from_target (from_type, from, &host_float); |
| 1076 | to_target (to_type, &host_float, to); |
| 1077 | } |
| 1078 | |
| 1079 | /* Perform the binary operation indicated by OPCODE, using as operands the |
| 1080 | target byte streams X and Y, interpreted as floating-point numbers of |
| 1081 | types TYPE_X and TYPE_Y, respectively. Convert the result to format |
| 1082 | TYPE_RES and store it into the byte-stream RES. */ |
| 1083 | template<typename T> void |
| 1084 | host_float_ops<T>::binop (enum exp_opcode op, |
| 1085 | const gdb_byte *x, const struct type *type_x, |
| 1086 | const gdb_byte *y, const struct type *type_y, |
| 1087 | gdb_byte *res, const struct type *type_res) const |
| 1088 | { |
| 1089 | T v1, v2, v = 0; |
| 1090 | |
| 1091 | from_target (type_x, x, &v1); |
| 1092 | from_target (type_y, y, &v2); |
| 1093 | |
| 1094 | switch (op) |
| 1095 | { |
| 1096 | case BINOP_ADD: |
| 1097 | v = v1 + v2; |
| 1098 | break; |
| 1099 | |
| 1100 | case BINOP_SUB: |
| 1101 | v = v1 - v2; |
| 1102 | break; |
| 1103 | |
| 1104 | case BINOP_MUL: |
| 1105 | v = v1 * v2; |
| 1106 | break; |
| 1107 | |
| 1108 | case BINOP_DIV: |
| 1109 | v = v1 / v2; |
| 1110 | break; |
| 1111 | |
| 1112 | case BINOP_EXP: |
| 1113 | errno = 0; |
| 1114 | v = pow (v1, v2); |
| 1115 | if (errno) |
| 1116 | error (_("Cannot perform exponentiation: %s"), |
| 1117 | safe_strerror (errno)); |
| 1118 | break; |
| 1119 | |
| 1120 | case BINOP_MIN: |
| 1121 | v = v1 < v2 ? v1 : v2; |
| 1122 | break; |
| 1123 | |
| 1124 | case BINOP_MAX: |
| 1125 | v = v1 > v2 ? v1 : v2; |
| 1126 | break; |
| 1127 | |
| 1128 | default: |
| 1129 | error (_("Integer-only operation on floating point number.")); |
| 1130 | break; |
| 1131 | } |
| 1132 | |
| 1133 | to_target (type_res, &v, res); |
| 1134 | } |
| 1135 | |
| 1136 | /* Compare the two target byte streams X and Y, interpreted as floating-point |
| 1137 | numbers of types TYPE_X and TYPE_Y, respectively. Return zero if X and Y |
| 1138 | are equal, -1 if X is less than Y, and 1 otherwise. */ |
| 1139 | template<typename T> int |
| 1140 | host_float_ops<T>::compare (const gdb_byte *x, const struct type *type_x, |
| 1141 | const gdb_byte *y, const struct type *type_y) const |
| 1142 | { |
| 1143 | T v1, v2; |
| 1144 | |
| 1145 | from_target (type_x, x, &v1); |
| 1146 | from_target (type_y, y, &v2); |
| 1147 | |
| 1148 | if (v1 == v2) |
| 1149 | return 0; |
| 1150 | if (v1 < v2) |
| 1151 | return -1; |
| 1152 | return 1; |
| 1153 | } |
| 1154 | |
| 1155 | |
| 1156 | /* Implementation of target_float_ops using the MPFR library |
| 1157 | mpfr_t as intermediate type. */ |
| 1158 | |
| 1159 | #ifdef HAVE_LIBMPFR |
| 1160 | |
| 1161 | #define MPFR_USE_INTMAX_T |
| 1162 | |
| 1163 | #include <mpfr.h> |
| 1164 | |
| 1165 | class mpfr_float_ops : public target_float_ops |
| 1166 | { |
| 1167 | public: |
| 1168 | std::string to_string (const gdb_byte *addr, const struct type *type, |
| 1169 | const char *format) const override; |
| 1170 | bool from_string (gdb_byte *addr, const struct type *type, |
| 1171 | const std::string &string) const override; |
| 1172 | |
| 1173 | LONGEST to_longest (const gdb_byte *addr, |
| 1174 | const struct type *type) const override; |
| 1175 | void from_longest (gdb_byte *addr, const struct type *type, |
| 1176 | LONGEST val) const override; |
| 1177 | void from_ulongest (gdb_byte *addr, const struct type *type, |
| 1178 | ULONGEST val) const override; |
| 1179 | double to_host_double (const gdb_byte *addr, |
| 1180 | const struct type *type) const override; |
| 1181 | void from_host_double (gdb_byte *addr, const struct type *type, |
| 1182 | double val) const override; |
| 1183 | void convert (const gdb_byte *from, const struct type *from_type, |
| 1184 | gdb_byte *to, const struct type *to_type) const override; |
| 1185 | |
| 1186 | void binop (enum exp_opcode opcode, |
| 1187 | const gdb_byte *x, const struct type *type_x, |
| 1188 | const gdb_byte *y, const struct type *type_y, |
| 1189 | gdb_byte *res, const struct type *type_res) const override; |
| 1190 | int compare (const gdb_byte *x, const struct type *type_x, |
| 1191 | const gdb_byte *y, const struct type *type_y) const override; |
| 1192 | |
| 1193 | private: |
| 1194 | /* Local wrapper class to handle mpfr_t initalization and cleanup. */ |
| 1195 | class gdb_mpfr |
| 1196 | { |
| 1197 | public: |
| 1198 | mpfr_t val; |
| 1199 | |
| 1200 | gdb_mpfr (const struct type *type) |
| 1201 | { |
| 1202 | const struct floatformat *fmt = floatformat_from_type (type); |
| 1203 | mpfr_init2 (val, floatformat_precision (fmt)); |
| 1204 | } |
| 1205 | |
| 1206 | gdb_mpfr (const gdb_mpfr &source) |
| 1207 | { |
| 1208 | mpfr_init2 (val, mpfr_get_prec (source.val)); |
| 1209 | } |
| 1210 | |
| 1211 | ~gdb_mpfr () |
| 1212 | { |
| 1213 | mpfr_clear (val); |
| 1214 | } |
| 1215 | }; |
| 1216 | |
| 1217 | void from_target (const struct floatformat *fmt, |
| 1218 | const gdb_byte *from, gdb_mpfr &to) const; |
| 1219 | void from_target (const struct type *type, |
| 1220 | const gdb_byte *from, gdb_mpfr &to) const; |
| 1221 | |
| 1222 | void to_target (const struct type *type, |
| 1223 | const gdb_mpfr &from, gdb_byte *to) const; |
| 1224 | void to_target (const struct floatformat *fmt, |
| 1225 | const gdb_mpfr &from, gdb_byte *to) const; |
| 1226 | }; |
| 1227 | |
| 1228 | |
| 1229 | /* Convert TO/FROM target floating-point format to mpfr_t. */ |
| 1230 | |
| 1231 | void |
| 1232 | mpfr_float_ops::from_target (const struct floatformat *fmt, |
| 1233 | const gdb_byte *orig_from, gdb_mpfr &to) const |
| 1234 | { |
| 1235 | const gdb_byte *from = orig_from; |
| 1236 | mpfr_exp_t exponent; |
| 1237 | unsigned long mant; |
| 1238 | unsigned int mant_bits, mant_off; |
| 1239 | int mant_bits_left; |
| 1240 | int special_exponent; /* It's a NaN, denorm or zero. */ |
| 1241 | enum floatformat_byteorders order; |
| 1242 | unsigned char newfrom[FLOATFORMAT_LARGEST_BYTES]; |
| 1243 | enum float_kind kind; |
| 1244 | |
| 1245 | gdb_assert (fmt->totalsize |
| 1246 | <= FLOATFORMAT_LARGEST_BYTES * FLOATFORMAT_CHAR_BIT); |
| 1247 | |
| 1248 | /* Handle non-numbers. */ |
| 1249 | kind = floatformat_classify (fmt, from); |
| 1250 | if (kind == float_infinite) |
| 1251 | { |
| 1252 | mpfr_set_inf (to.val, floatformat_is_negative (fmt, from) ? -1 : 1); |
| 1253 | return; |
| 1254 | } |
| 1255 | if (kind == float_nan) |
| 1256 | { |
| 1257 | mpfr_set_nan (to.val); |
| 1258 | return; |
| 1259 | } |
| 1260 | |
| 1261 | order = floatformat_normalize_byteorder (fmt, from, newfrom); |
| 1262 | |
| 1263 | if (order != fmt->byteorder) |
| 1264 | from = newfrom; |
| 1265 | |
| 1266 | if (fmt->split_half) |
| 1267 | { |
| 1268 | gdb_mpfr top (to), bot (to); |
| 1269 | |
| 1270 | from_target (fmt->split_half, from, top); |
| 1271 | /* Preserve the sign of 0, which is the sign of the top half. */ |
| 1272 | if (mpfr_zero_p (top.val)) |
| 1273 | { |
| 1274 | mpfr_set (to.val, top.val, MPFR_RNDN); |
| 1275 | return; |
| 1276 | } |
| 1277 | from_target (fmt->split_half, |
| 1278 | from + fmt->totalsize / FLOATFORMAT_CHAR_BIT / 2, bot); |
| 1279 | mpfr_add (to.val, top.val, bot.val, MPFR_RNDN); |
| 1280 | return; |
| 1281 | } |
| 1282 | |
| 1283 | exponent = get_field (from, order, fmt->totalsize, fmt->exp_start, |
| 1284 | fmt->exp_len); |
| 1285 | /* Note that if exponent indicates a NaN, we can't really do anything useful |
| 1286 | (not knowing if the host has NaN's, or how to build one). So it will |
| 1287 | end up as an infinity or something close; that is OK. */ |
| 1288 | |
| 1289 | mant_bits_left = fmt->man_len; |
| 1290 | mant_off = fmt->man_start; |
| 1291 | mpfr_set_zero (to.val, 0); |
| 1292 | |
| 1293 | special_exponent = exponent == 0 || exponent == fmt->exp_nan; |
| 1294 | |
| 1295 | /* Don't bias NaNs. Use minimum exponent for denorms. For |
| 1296 | simplicity, we don't check for zero as the exponent doesn't matter. |
| 1297 | Note the cast to int; exp_bias is unsigned, so it's important to |
| 1298 | make sure the operation is done in signed arithmetic. */ |
| 1299 | if (!special_exponent) |
| 1300 | exponent -= fmt->exp_bias; |
| 1301 | else if (exponent == 0) |
| 1302 | exponent = 1 - fmt->exp_bias; |
| 1303 | |
| 1304 | /* Build the result algebraically. Might go infinite, underflow, etc; |
| 1305 | who cares. */ |
| 1306 | |
| 1307 | /* If this format uses a hidden bit, explicitly add it in now. Otherwise, |
| 1308 | increment the exponent by one to account for the integer bit. */ |
| 1309 | |
| 1310 | if (!special_exponent) |
| 1311 | { |
| 1312 | if (fmt->intbit == floatformat_intbit_no) |
| 1313 | mpfr_set_ui_2exp (to.val, 1, exponent, MPFR_RNDN); |
| 1314 | else |
| 1315 | exponent++; |
| 1316 | } |
| 1317 | |
| 1318 | gdb_mpfr tmp (to); |
| 1319 | |
| 1320 | while (mant_bits_left > 0) |
| 1321 | { |
| 1322 | mant_bits = std::min (mant_bits_left, 32); |
| 1323 | |
| 1324 | mant = get_field (from, order, fmt->totalsize, mant_off, mant_bits); |
| 1325 | |
| 1326 | mpfr_set_ui (tmp.val, mant, MPFR_RNDN); |
| 1327 | mpfr_mul_2si (tmp.val, tmp.val, exponent - mant_bits, MPFR_RNDN); |
| 1328 | mpfr_add (to.val, to.val, tmp.val, MPFR_RNDN); |
| 1329 | exponent -= mant_bits; |
| 1330 | mant_off += mant_bits; |
| 1331 | mant_bits_left -= mant_bits; |
| 1332 | } |
| 1333 | |
| 1334 | /* Negate it if negative. */ |
| 1335 | if (get_field (from, order, fmt->totalsize, fmt->sign_start, 1)) |
| 1336 | mpfr_neg (to.val, to.val, MPFR_RNDN); |
| 1337 | } |
| 1338 | |
| 1339 | void |
| 1340 | mpfr_float_ops::from_target (const struct type *type, |
| 1341 | const gdb_byte *from, gdb_mpfr &to) const |
| 1342 | { |
| 1343 | from_target (floatformat_from_type (type), from, to); |
| 1344 | } |
| 1345 | |
| 1346 | void |
| 1347 | mpfr_float_ops::to_target (const struct floatformat *fmt, |
| 1348 | const gdb_mpfr &from, gdb_byte *orig_to) const |
| 1349 | { |
| 1350 | unsigned char *to = orig_to; |
| 1351 | mpfr_exp_t exponent; |
| 1352 | unsigned int mant_bits, mant_off; |
| 1353 | int mant_bits_left; |
| 1354 | enum floatformat_byteorders order = fmt->byteorder; |
| 1355 | unsigned char newto[FLOATFORMAT_LARGEST_BYTES]; |
| 1356 | |
| 1357 | if (order != floatformat_little) |
| 1358 | order = floatformat_big; |
| 1359 | |
| 1360 | if (order != fmt->byteorder) |
| 1361 | to = newto; |
| 1362 | |
| 1363 | memset (to, 0, floatformat_totalsize_bytes (fmt)); |
| 1364 | |
| 1365 | if (fmt->split_half) |
| 1366 | { |
| 1367 | gdb_mpfr top (from), bot (from); |
| 1368 | |
| 1369 | mpfr_set (top.val, from.val, MPFR_RNDN); |
| 1370 | /* If the rounded top half is Inf, the bottom must be 0 not NaN |
| 1371 | or Inf. */ |
| 1372 | if (mpfr_inf_p (top.val)) |
| 1373 | mpfr_set_zero (bot.val, 0); |
| 1374 | else |
| 1375 | mpfr_sub (bot.val, from.val, top.val, MPFR_RNDN); |
| 1376 | |
| 1377 | to_target (fmt->split_half, top, to); |
| 1378 | to_target (fmt->split_half, bot, |
| 1379 | to + fmt->totalsize / FLOATFORMAT_CHAR_BIT / 2); |
| 1380 | return; |
| 1381 | } |
| 1382 | |
| 1383 | gdb_mpfr tmp (from); |
| 1384 | |
| 1385 | if (mpfr_zero_p (from.val)) |
| 1386 | goto finalize_byteorder; /* Result is zero */ |
| 1387 | |
| 1388 | mpfr_set (tmp.val, from.val, MPFR_RNDN); |
| 1389 | |
| 1390 | if (mpfr_nan_p (tmp.val)) /* Result is NaN */ |
| 1391 | { |
| 1392 | /* From is NaN */ |
| 1393 | put_field (to, order, fmt->totalsize, fmt->exp_start, |
| 1394 | fmt->exp_len, fmt->exp_nan); |
| 1395 | /* Be sure it's not infinity, but NaN value is irrel. */ |
| 1396 | put_field (to, order, fmt->totalsize, fmt->man_start, |
| 1397 | fmt->man_len, 1); |
| 1398 | goto finalize_byteorder; |
| 1399 | } |
| 1400 | |
| 1401 | /* If negative, set the sign bit. */ |
| 1402 | if (mpfr_sgn (tmp.val) < 0) |
| 1403 | { |
| 1404 | put_field (to, order, fmt->totalsize, fmt->sign_start, 1, 1); |
| 1405 | mpfr_neg (tmp.val, tmp.val, MPFR_RNDN); |
| 1406 | } |
| 1407 | |
| 1408 | if (mpfr_inf_p (tmp.val)) /* Result is Infinity. */ |
| 1409 | { |
| 1410 | /* Infinity exponent is same as NaN's. */ |
| 1411 | put_field (to, order, fmt->totalsize, fmt->exp_start, |
| 1412 | fmt->exp_len, fmt->exp_nan); |
| 1413 | /* Infinity mantissa is all zeroes. */ |
| 1414 | put_field (to, order, fmt->totalsize, fmt->man_start, |
| 1415 | fmt->man_len, 0); |
| 1416 | goto finalize_byteorder; |
| 1417 | } |
| 1418 | |
| 1419 | mpfr_frexp (&exponent, tmp.val, tmp.val, MPFR_RNDN); |
| 1420 | |
| 1421 | if (exponent + fmt->exp_bias <= 0) |
| 1422 | { |
| 1423 | /* The value is too small to be expressed in the destination |
| 1424 | type (not enough bits in the exponent. Treat as 0. */ |
| 1425 | put_field (to, order, fmt->totalsize, fmt->exp_start, |
| 1426 | fmt->exp_len, 0); |
| 1427 | put_field (to, order, fmt->totalsize, fmt->man_start, |
| 1428 | fmt->man_len, 0); |
| 1429 | goto finalize_byteorder; |
| 1430 | } |
| 1431 | |
| 1432 | if (exponent + fmt->exp_bias >= (1 << fmt->exp_len)) |
| 1433 | { |
| 1434 | /* The value is too large to fit into the destination. |
| 1435 | Treat as infinity. */ |
| 1436 | put_field (to, order, fmt->totalsize, fmt->exp_start, |
| 1437 | fmt->exp_len, fmt->exp_nan); |
| 1438 | put_field (to, order, fmt->totalsize, fmt->man_start, |
| 1439 | fmt->man_len, 0); |
| 1440 | goto finalize_byteorder; |
| 1441 | } |
| 1442 | |
| 1443 | put_field (to, order, fmt->totalsize, fmt->exp_start, fmt->exp_len, |
| 1444 | exponent + fmt->exp_bias - 1); |
| 1445 | |
| 1446 | mant_bits_left = fmt->man_len; |
| 1447 | mant_off = fmt->man_start; |
| 1448 | while (mant_bits_left > 0) |
| 1449 | { |
| 1450 | unsigned long mant_long; |
| 1451 | |
| 1452 | mant_bits = mant_bits_left < 32 ? mant_bits_left : 32; |
| 1453 | |
| 1454 | mpfr_mul_2ui (tmp.val, tmp.val, 32, MPFR_RNDN); |
| 1455 | mant_long = mpfr_get_ui (tmp.val, MPFR_RNDZ) & 0xffffffffL; |
| 1456 | mpfr_sub_ui (tmp.val, tmp.val, mant_long, MPFR_RNDZ); |
| 1457 | |
| 1458 | /* If the integer bit is implicit, then we need to discard it. |
| 1459 | If we are discarding a zero, we should be (but are not) creating |
| 1460 | a denormalized number which means adjusting the exponent |
| 1461 | (I think). */ |
| 1462 | if (mant_bits_left == fmt->man_len |
| 1463 | && fmt->intbit == floatformat_intbit_no) |
| 1464 | { |
| 1465 | mant_long <<= 1; |
| 1466 | mant_long &= 0xffffffffL; |
| 1467 | /* If we are processing the top 32 mantissa bits of a doublest |
| 1468 | so as to convert to a float value with implied integer bit, |
| 1469 | we will only be putting 31 of those 32 bits into the |
| 1470 | final value due to the discarding of the top bit. In the |
| 1471 | case of a small float value where the number of mantissa |
| 1472 | bits is less than 32, discarding the top bit does not alter |
| 1473 | the number of bits we will be adding to the result. */ |
| 1474 | if (mant_bits == 32) |
| 1475 | mant_bits -= 1; |
| 1476 | } |
| 1477 | |
| 1478 | if (mant_bits < 32) |
| 1479 | { |
| 1480 | /* The bits we want are in the most significant MANT_BITS bits of |
| 1481 | mant_long. Move them to the least significant. */ |
| 1482 | mant_long >>= 32 - mant_bits; |
| 1483 | } |
| 1484 | |
| 1485 | put_field (to, order, fmt->totalsize, |
| 1486 | mant_off, mant_bits, mant_long); |
| 1487 | mant_off += mant_bits; |
| 1488 | mant_bits_left -= mant_bits; |
| 1489 | } |
| 1490 | |
| 1491 | finalize_byteorder: |
| 1492 | /* Do we need to byte-swap the words in the result? */ |
| 1493 | if (order != fmt->byteorder) |
| 1494 | floatformat_normalize_byteorder (fmt, newto, orig_to); |
| 1495 | } |
| 1496 | |
| 1497 | void |
| 1498 | mpfr_float_ops::to_target (const struct type *type, |
| 1499 | const gdb_mpfr &from, gdb_byte *to) const |
| 1500 | { |
| 1501 | /* Ensure possible padding bytes in the target buffer are zeroed out. */ |
| 1502 | memset (to, 0, TYPE_LENGTH (type)); |
| 1503 | |
| 1504 | to_target (floatformat_from_type (type), from, to); |
| 1505 | } |
| 1506 | |
| 1507 | /* Convert the byte-stream ADDR, interpreted as floating-point type TYPE, |
| 1508 | to a string, optionally using the print format FORMAT. */ |
| 1509 | std::string |
| 1510 | mpfr_float_ops::to_string (const gdb_byte *addr, |
| 1511 | const struct type *type, |
| 1512 | const char *format) const |
| 1513 | { |
| 1514 | const struct floatformat *fmt = floatformat_from_type (type); |
| 1515 | |
| 1516 | /* Unless we need to adhere to a specific format, provide special |
| 1517 | output for certain cases. */ |
| 1518 | if (format == nullptr) |
| 1519 | { |
| 1520 | /* Detect invalid representations. */ |
| 1521 | if (!floatformat_is_valid (fmt, addr)) |
| 1522 | return "<invalid float value>"; |
| 1523 | |
| 1524 | /* Handle NaN and Inf. */ |
| 1525 | enum float_kind kind = floatformat_classify (fmt, addr); |
| 1526 | if (kind == float_nan) |
| 1527 | { |
| 1528 | const char *sign = floatformat_is_negative (fmt, addr)? "-" : ""; |
| 1529 | const char *mantissa = floatformat_mantissa (fmt, addr); |
| 1530 | return string_printf ("%snan(0x%s)", sign, mantissa); |
| 1531 | } |
| 1532 | else if (kind == float_infinite) |
| 1533 | { |
| 1534 | const char *sign = floatformat_is_negative (fmt, addr)? "-" : ""; |
| 1535 | return string_printf ("%sinf", sign); |
| 1536 | } |
| 1537 | } |
| 1538 | |
| 1539 | /* Determine the format string to use on the host side. */ |
| 1540 | std::string host_format = floatformat_printf_format (fmt, format, 'R'); |
| 1541 | |
| 1542 | gdb_mpfr tmp (type); |
| 1543 | from_target (type, addr, tmp); |
| 1544 | |
| 1545 | int size = mpfr_snprintf (NULL, 0, host_format.c_str (), tmp.val); |
| 1546 | std::string str (size, '\0'); |
| 1547 | mpfr_sprintf (&str[0], host_format.c_str (), tmp.val); |
| 1548 | |
| 1549 | return str; |
| 1550 | } |
| 1551 | |
| 1552 | /* Parse string STRING into a target floating-number of type TYPE and |
| 1553 | store it as byte-stream ADDR. Return whether parsing succeeded. */ |
| 1554 | bool |
| 1555 | mpfr_float_ops::from_string (gdb_byte *addr, |
| 1556 | const struct type *type, |
| 1557 | const std::string &in) const |
| 1558 | { |
| 1559 | gdb_mpfr tmp (type); |
| 1560 | |
| 1561 | char *endptr; |
| 1562 | mpfr_strtofr (tmp.val, in.c_str (), &endptr, 0, MPFR_RNDN); |
| 1563 | |
| 1564 | /* We only accept the whole string. */ |
| 1565 | if (*endptr) |
| 1566 | return false; |
| 1567 | |
| 1568 | to_target (type, tmp, addr); |
| 1569 | return true; |
| 1570 | } |
| 1571 | |
| 1572 | /* Convert the byte-stream ADDR, interpreted as floating-point type TYPE, |
| 1573 | to an integer value (rounding towards zero). */ |
| 1574 | LONGEST |
| 1575 | mpfr_float_ops::to_longest (const gdb_byte *addr, |
| 1576 | const struct type *type) const |
| 1577 | { |
| 1578 | gdb_mpfr tmp (type); |
| 1579 | from_target (type, addr, tmp); |
| 1580 | return mpfr_get_sj (tmp.val, MPFR_RNDZ); |
| 1581 | } |
| 1582 | |
| 1583 | /* Convert signed integer VAL to a target floating-number of type TYPE |
| 1584 | and store it as byte-stream ADDR. */ |
| 1585 | void |
| 1586 | mpfr_float_ops::from_longest (gdb_byte *addr, |
| 1587 | const struct type *type, |
| 1588 | LONGEST val) const |
| 1589 | { |
| 1590 | gdb_mpfr tmp (type); |
| 1591 | mpfr_set_sj (tmp.val, val, MPFR_RNDN); |
| 1592 | to_target (type, tmp, addr); |
| 1593 | } |
| 1594 | |
| 1595 | /* Convert unsigned integer VAL to a target floating-number of type TYPE |
| 1596 | and store it as byte-stream ADDR. */ |
| 1597 | void |
| 1598 | mpfr_float_ops::from_ulongest (gdb_byte *addr, |
| 1599 | const struct type *type, |
| 1600 | ULONGEST val) const |
| 1601 | { |
| 1602 | gdb_mpfr tmp (type); |
| 1603 | mpfr_set_uj (tmp.val, val, MPFR_RNDN); |
| 1604 | to_target (type, tmp, addr); |
| 1605 | } |
| 1606 | |
| 1607 | /* Convert the byte-stream ADDR, interpreted as floating-point type TYPE, |
| 1608 | to a floating-point value in the host "double" format. */ |
| 1609 | double |
| 1610 | mpfr_float_ops::to_host_double (const gdb_byte *addr, |
| 1611 | const struct type *type) const |
| 1612 | { |
| 1613 | gdb_mpfr tmp (type); |
| 1614 | from_target (type, addr, tmp); |
| 1615 | return mpfr_get_d (tmp.val, MPFR_RNDN); |
| 1616 | } |
| 1617 | |
| 1618 | /* Convert floating-point value VAL in the host "double" format to a target |
| 1619 | floating-number of type TYPE and store it as byte-stream ADDR. */ |
| 1620 | void |
| 1621 | mpfr_float_ops::from_host_double (gdb_byte *addr, |
| 1622 | const struct type *type, |
| 1623 | double val) const |
| 1624 | { |
| 1625 | gdb_mpfr tmp (type); |
| 1626 | mpfr_set_d (tmp.val, val, MPFR_RNDN); |
| 1627 | to_target (type, tmp, addr); |
| 1628 | } |
| 1629 | |
| 1630 | /* Convert a floating-point number of type FROM_TYPE from the target |
| 1631 | byte-stream FROM to a floating-point number of type TO_TYPE, and |
| 1632 | store it to the target byte-stream TO. */ |
| 1633 | void |
| 1634 | mpfr_float_ops::convert (const gdb_byte *from, |
| 1635 | const struct type *from_type, |
| 1636 | gdb_byte *to, |
| 1637 | const struct type *to_type) const |
| 1638 | { |
| 1639 | gdb_mpfr from_tmp (from_type), to_tmp (to_type); |
| 1640 | from_target (from_type, from, from_tmp); |
| 1641 | mpfr_set (to_tmp.val, from_tmp.val, MPFR_RNDN); |
| 1642 | to_target (to_type, to_tmp, to); |
| 1643 | } |
| 1644 | |
| 1645 | /* Perform the binary operation indicated by OPCODE, using as operands the |
| 1646 | target byte streams X and Y, interpreted as floating-point numbers of |
| 1647 | types TYPE_X and TYPE_Y, respectively. Convert the result to type |
| 1648 | TYPE_RES and store it into the byte-stream RES. */ |
| 1649 | void |
| 1650 | mpfr_float_ops::binop (enum exp_opcode op, |
| 1651 | const gdb_byte *x, const struct type *type_x, |
| 1652 | const gdb_byte *y, const struct type *type_y, |
| 1653 | gdb_byte *res, const struct type *type_res) const |
| 1654 | { |
| 1655 | gdb_mpfr x_tmp (type_x), y_tmp (type_y), tmp (type_res); |
| 1656 | |
| 1657 | from_target (type_x, x, x_tmp); |
| 1658 | from_target (type_y, y, y_tmp); |
| 1659 | |
| 1660 | switch (op) |
| 1661 | { |
| 1662 | case BINOP_ADD: |
| 1663 | mpfr_add (tmp.val, x_tmp.val, y_tmp.val, MPFR_RNDN); |
| 1664 | break; |
| 1665 | |
| 1666 | case BINOP_SUB: |
| 1667 | mpfr_sub (tmp.val, x_tmp.val, y_tmp.val, MPFR_RNDN); |
| 1668 | break; |
| 1669 | |
| 1670 | case BINOP_MUL: |
| 1671 | mpfr_mul (tmp.val, x_tmp.val, y_tmp.val, MPFR_RNDN); |
| 1672 | break; |
| 1673 | |
| 1674 | case BINOP_DIV: |
| 1675 | mpfr_div (tmp.val, x_tmp.val, y_tmp.val, MPFR_RNDN); |
| 1676 | break; |
| 1677 | |
| 1678 | case BINOP_EXP: |
| 1679 | mpfr_pow (tmp.val, x_tmp.val, y_tmp.val, MPFR_RNDN); |
| 1680 | break; |
| 1681 | |
| 1682 | case BINOP_MIN: |
| 1683 | mpfr_min (tmp.val, x_tmp.val, y_tmp.val, MPFR_RNDN); |
| 1684 | break; |
| 1685 | |
| 1686 | case BINOP_MAX: |
| 1687 | mpfr_max (tmp.val, x_tmp.val, y_tmp.val, MPFR_RNDN); |
| 1688 | break; |
| 1689 | |
| 1690 | default: |
| 1691 | error (_("Integer-only operation on floating point number.")); |
| 1692 | break; |
| 1693 | } |
| 1694 | |
| 1695 | to_target (type_res, tmp, res); |
| 1696 | } |
| 1697 | |
| 1698 | /* Compare the two target byte streams X and Y, interpreted as floating-point |
| 1699 | numbers of types TYPE_X and TYPE_Y, respectively. Return zero if X and Y |
| 1700 | are equal, -1 if X is less than Y, and 1 otherwise. */ |
| 1701 | int |
| 1702 | mpfr_float_ops::compare (const gdb_byte *x, const struct type *type_x, |
| 1703 | const gdb_byte *y, const struct type *type_y) const |
| 1704 | { |
| 1705 | gdb_mpfr x_tmp (type_x), y_tmp (type_y); |
| 1706 | |
| 1707 | from_target (type_x, x, x_tmp); |
| 1708 | from_target (type_y, y, y_tmp); |
| 1709 | |
| 1710 | if (mpfr_equal_p (x_tmp.val, y_tmp.val)) |
| 1711 | return 0; |
| 1712 | else if (mpfr_less_p (x_tmp.val, y_tmp.val)) |
| 1713 | return -1; |
| 1714 | else |
| 1715 | return 1; |
| 1716 | } |
| 1717 | |
| 1718 | #endif |
| 1719 | |
| 1720 | |
| 1721 | /* Helper routines operating on decimal floating-point data. */ |
| 1722 | |
| 1723 | /* Decimal floating point is one of the extension to IEEE 754, which is |
| 1724 | described in http://grouper.ieee.org/groups/754/revision.html and |
| 1725 | http://www2.hursley.ibm.com/decimal/. It completes binary floating |
| 1726 | point by representing floating point more exactly. */ |
| 1727 | |
| 1728 | /* The order of the following headers is important for making sure |
| 1729 | decNumber structure is large enough to hold decimal128 digits. */ |
| 1730 | |
| 1731 | #include "dpd/decimal128.h" |
| 1732 | #include "dpd/decimal64.h" |
| 1733 | #include "dpd/decimal32.h" |
| 1734 | |
| 1735 | /* When using decimal128, this is the maximum string length + 1 |
| 1736 | (value comes from libdecnumber's DECIMAL128_String constant). */ |
| 1737 | #define MAX_DECIMAL_STRING 43 |
| 1738 | |
| 1739 | /* In GDB, we are using an array of gdb_byte to represent decimal values. |
| 1740 | They are stored in host byte order. This routine does the conversion if |
| 1741 | the target byte order is different. */ |
| 1742 | static void |
| 1743 | match_endianness (const gdb_byte *from, const struct type *type, gdb_byte *to) |
| 1744 | { |
| 1745 | gdb_assert (type->code () == TYPE_CODE_DECFLOAT); |
| 1746 | |
| 1747 | int len = TYPE_LENGTH (type); |
| 1748 | int i; |
| 1749 | |
| 1750 | #if WORDS_BIGENDIAN |
| 1751 | #define OPPOSITE_BYTE_ORDER BFD_ENDIAN_LITTLE |
| 1752 | #else |
| 1753 | #define OPPOSITE_BYTE_ORDER BFD_ENDIAN_BIG |
| 1754 | #endif |
| 1755 | |
| 1756 | if (type_byte_order (type) == OPPOSITE_BYTE_ORDER) |
| 1757 | for (i = 0; i < len; i++) |
| 1758 | to[i] = from[len - i - 1]; |
| 1759 | else |
| 1760 | for (i = 0; i < len; i++) |
| 1761 | to[i] = from[i]; |
| 1762 | |
| 1763 | return; |
| 1764 | } |
| 1765 | |
| 1766 | /* Helper function to get the appropriate libdecnumber context for each size |
| 1767 | of decimal float. */ |
| 1768 | static void |
| 1769 | set_decnumber_context (decContext *ctx, const struct type *type) |
| 1770 | { |
| 1771 | gdb_assert (type->code () == TYPE_CODE_DECFLOAT); |
| 1772 | |
| 1773 | switch (TYPE_LENGTH (type)) |
| 1774 | { |
| 1775 | case 4: |
| 1776 | decContextDefault (ctx, DEC_INIT_DECIMAL32); |
| 1777 | break; |
| 1778 | case 8: |
| 1779 | decContextDefault (ctx, DEC_INIT_DECIMAL64); |
| 1780 | break; |
| 1781 | case 16: |
| 1782 | decContextDefault (ctx, DEC_INIT_DECIMAL128); |
| 1783 | break; |
| 1784 | } |
| 1785 | |
| 1786 | ctx->traps = 0; |
| 1787 | } |
| 1788 | |
| 1789 | /* Check for errors signaled in the decimal context structure. */ |
| 1790 | static void |
| 1791 | decimal_check_errors (decContext *ctx) |
| 1792 | { |
| 1793 | /* An error here could be a division by zero, an overflow, an underflow or |
| 1794 | an invalid operation (from the DEC_Errors constant in decContext.h). |
| 1795 | Since GDB doesn't complain about division by zero, overflow or underflow |
| 1796 | errors for binary floating, we won't complain about them for decimal |
| 1797 | floating either. */ |
| 1798 | if (ctx->status & DEC_IEEE_854_Invalid_operation) |
| 1799 | { |
| 1800 | /* Leave only the error bits in the status flags. */ |
| 1801 | ctx->status &= DEC_IEEE_854_Invalid_operation; |
| 1802 | error (_("Cannot perform operation: %s"), |
| 1803 | decContextStatusToString (ctx)); |
| 1804 | } |
| 1805 | } |
| 1806 | |
| 1807 | /* Helper function to convert from libdecnumber's appropriate representation |
| 1808 | for computation to each size of decimal float. */ |
| 1809 | static void |
| 1810 | decimal_from_number (const decNumber *from, |
| 1811 | gdb_byte *to, const struct type *type) |
| 1812 | { |
| 1813 | gdb_byte dec[16]; |
| 1814 | |
| 1815 | decContext set; |
| 1816 | |
| 1817 | set_decnumber_context (&set, type); |
| 1818 | |
| 1819 | switch (TYPE_LENGTH (type)) |
| 1820 | { |
| 1821 | case 4: |
| 1822 | decimal32FromNumber ((decimal32 *) dec, from, &set); |
| 1823 | break; |
| 1824 | case 8: |
| 1825 | decimal64FromNumber ((decimal64 *) dec, from, &set); |
| 1826 | break; |
| 1827 | case 16: |
| 1828 | decimal128FromNumber ((decimal128 *) dec, from, &set); |
| 1829 | break; |
| 1830 | default: |
| 1831 | error (_("Unknown decimal floating point type.")); |
| 1832 | break; |
| 1833 | } |
| 1834 | |
| 1835 | match_endianness (dec, type, to); |
| 1836 | } |
| 1837 | |
| 1838 | /* Helper function to convert each size of decimal float to libdecnumber's |
| 1839 | appropriate representation for computation. */ |
| 1840 | static void |
| 1841 | decimal_to_number (const gdb_byte *addr, const struct type *type, |
| 1842 | decNumber *to) |
| 1843 | { |
| 1844 | gdb_byte dec[16]; |
| 1845 | match_endianness (addr, type, dec); |
| 1846 | |
| 1847 | switch (TYPE_LENGTH (type)) |
| 1848 | { |
| 1849 | case 4: |
| 1850 | decimal32ToNumber ((decimal32 *) dec, to); |
| 1851 | break; |
| 1852 | case 8: |
| 1853 | decimal64ToNumber ((decimal64 *) dec, to); |
| 1854 | break; |
| 1855 | case 16: |
| 1856 | decimal128ToNumber ((decimal128 *) dec, to); |
| 1857 | break; |
| 1858 | default: |
| 1859 | error (_("Unknown decimal floating point type.")); |
| 1860 | break; |
| 1861 | } |
| 1862 | } |
| 1863 | |
| 1864 | /* Returns true if ADDR (which is of type TYPE) is the number zero. */ |
| 1865 | static bool |
| 1866 | decimal_is_zero (const gdb_byte *addr, const struct type *type) |
| 1867 | { |
| 1868 | decNumber number; |
| 1869 | |
| 1870 | decimal_to_number (addr, type, &number); |
| 1871 | |
| 1872 | return decNumberIsZero (&number); |
| 1873 | } |
| 1874 | |
| 1875 | |
| 1876 | /* Implementation of target_float_ops using the libdecnumber decNumber type |
| 1877 | as intermediate format. */ |
| 1878 | |
| 1879 | class decimal_float_ops : public target_float_ops |
| 1880 | { |
| 1881 | public: |
| 1882 | std::string to_string (const gdb_byte *addr, const struct type *type, |
| 1883 | const char *format) const override; |
| 1884 | bool from_string (gdb_byte *addr, const struct type *type, |
| 1885 | const std::string &string) const override; |
| 1886 | |
| 1887 | LONGEST to_longest (const gdb_byte *addr, |
| 1888 | const struct type *type) const override; |
| 1889 | void from_longest (gdb_byte *addr, const struct type *type, |
| 1890 | LONGEST val) const override; |
| 1891 | void from_ulongest (gdb_byte *addr, const struct type *type, |
| 1892 | ULONGEST val) const override; |
| 1893 | double to_host_double (const gdb_byte *addr, |
| 1894 | const struct type *type) const override |
| 1895 | { |
| 1896 | /* We don't support conversions between target decimal floating-point |
| 1897 | types and the host double type. */ |
| 1898 | gdb_assert_not_reached ("invalid operation on decimal float"); |
| 1899 | } |
| 1900 | void from_host_double (gdb_byte *addr, const struct type *type, |
| 1901 | double val) const override |
| 1902 | { |
| 1903 | /* We don't support conversions between target decimal floating-point |
| 1904 | types and the host double type. */ |
| 1905 | gdb_assert_not_reached ("invalid operation on decimal float"); |
| 1906 | } |
| 1907 | void convert (const gdb_byte *from, const struct type *from_type, |
| 1908 | gdb_byte *to, const struct type *to_type) const override; |
| 1909 | |
| 1910 | void binop (enum exp_opcode opcode, |
| 1911 | const gdb_byte *x, const struct type *type_x, |
| 1912 | const gdb_byte *y, const struct type *type_y, |
| 1913 | gdb_byte *res, const struct type *type_res) const override; |
| 1914 | int compare (const gdb_byte *x, const struct type *type_x, |
| 1915 | const gdb_byte *y, const struct type *type_y) const override; |
| 1916 | }; |
| 1917 | |
| 1918 | /* Convert decimal type to its string representation. LEN is the length |
| 1919 | of the decimal type, 4 bytes for decimal32, 8 bytes for decimal64 and |
| 1920 | 16 bytes for decimal128. */ |
| 1921 | std::string |
| 1922 | decimal_float_ops::to_string (const gdb_byte *addr, const struct type *type, |
| 1923 | const char *format = nullptr) const |
| 1924 | { |
| 1925 | gdb_byte dec[16]; |
| 1926 | |
| 1927 | match_endianness (addr, type, dec); |
| 1928 | |
| 1929 | if (format != nullptr) |
| 1930 | { |
| 1931 | /* We don't handle format strings (yet). If the host printf supports |
| 1932 | decimal floating point types, just use this. Otherwise, fall back |
| 1933 | to printing the number while ignoring the format string. */ |
| 1934 | #if defined (PRINTF_HAS_DECFLOAT) |
| 1935 | /* FIXME: This makes unwarranted assumptions about the host ABI! */ |
| 1936 | return string_printf (format, dec); |
| 1937 | #endif |
| 1938 | } |
| 1939 | |
| 1940 | std::string result; |
| 1941 | result.resize (MAX_DECIMAL_STRING); |
| 1942 | |
| 1943 | switch (TYPE_LENGTH (type)) |
| 1944 | { |
| 1945 | case 4: |
| 1946 | decimal32ToString ((decimal32 *) dec, &result[0]); |
| 1947 | break; |
| 1948 | case 8: |
| 1949 | decimal64ToString ((decimal64 *) dec, &result[0]); |
| 1950 | break; |
| 1951 | case 16: |
| 1952 | decimal128ToString ((decimal128 *) dec, &result[0]); |
| 1953 | break; |
| 1954 | default: |
| 1955 | error (_("Unknown decimal floating point type.")); |
| 1956 | break; |
| 1957 | } |
| 1958 | |
| 1959 | return result; |
| 1960 | } |
| 1961 | |
| 1962 | /* Convert the string form of a decimal value to its decimal representation. |
| 1963 | LEN is the length of the decimal type, 4 bytes for decimal32, 8 bytes for |
| 1964 | decimal64 and 16 bytes for decimal128. */ |
| 1965 | bool |
| 1966 | decimal_float_ops::from_string (gdb_byte *addr, const struct type *type, |
| 1967 | const std::string &string) const |
| 1968 | { |
| 1969 | decContext set; |
| 1970 | gdb_byte dec[16]; |
| 1971 | |
| 1972 | set_decnumber_context (&set, type); |
| 1973 | |
| 1974 | switch (TYPE_LENGTH (type)) |
| 1975 | { |
| 1976 | case 4: |
| 1977 | decimal32FromString ((decimal32 *) dec, string.c_str (), &set); |
| 1978 | break; |
| 1979 | case 8: |
| 1980 | decimal64FromString ((decimal64 *) dec, string.c_str (), &set); |
| 1981 | break; |
| 1982 | case 16: |
| 1983 | decimal128FromString ((decimal128 *) dec, string.c_str (), &set); |
| 1984 | break; |
| 1985 | default: |
| 1986 | error (_("Unknown decimal floating point type.")); |
| 1987 | break; |
| 1988 | } |
| 1989 | |
| 1990 | match_endianness (dec, type, addr); |
| 1991 | |
| 1992 | /* Check for errors in the DFP operation. */ |
| 1993 | decimal_check_errors (&set); |
| 1994 | |
| 1995 | return true; |
| 1996 | } |
| 1997 | |
| 1998 | /* Converts a LONGEST to a decimal float of specified LEN bytes. */ |
| 1999 | void |
| 2000 | decimal_float_ops::from_longest (gdb_byte *addr, const struct type *type, |
| 2001 | LONGEST from) const |
| 2002 | { |
| 2003 | decNumber number; |
| 2004 | |
| 2005 | if ((int32_t) from != from) |
| 2006 | /* libdecnumber can convert only 32-bit integers. */ |
| 2007 | error (_("Conversion of large integer to a " |
| 2008 | "decimal floating type is not supported.")); |
| 2009 | |
| 2010 | decNumberFromInt32 (&number, (int32_t) from); |
| 2011 | |
| 2012 | decimal_from_number (&number, addr, type); |
| 2013 | } |
| 2014 | |
| 2015 | /* Converts a ULONGEST to a decimal float of specified LEN bytes. */ |
| 2016 | void |
| 2017 | decimal_float_ops::from_ulongest (gdb_byte *addr, const struct type *type, |
| 2018 | ULONGEST from) const |
| 2019 | { |
| 2020 | decNumber number; |
| 2021 | |
| 2022 | if ((uint32_t) from != from) |
| 2023 | /* libdecnumber can convert only 32-bit integers. */ |
| 2024 | error (_("Conversion of large integer to a " |
| 2025 | "decimal floating type is not supported.")); |
| 2026 | |
| 2027 | decNumberFromUInt32 (&number, (uint32_t) from); |
| 2028 | |
| 2029 | decimal_from_number (&number, addr, type); |
| 2030 | } |
| 2031 | |
| 2032 | /* Converts a decimal float of LEN bytes to a LONGEST. */ |
| 2033 | LONGEST |
| 2034 | decimal_float_ops::to_longest (const gdb_byte *addr, |
| 2035 | const struct type *type) const |
| 2036 | { |
| 2037 | /* libdecnumber has a function to convert from decimal to integer, but |
| 2038 | it doesn't work when the decimal number has a fractional part. */ |
| 2039 | std::string str = to_string (addr, type); |
| 2040 | return strtoll (str.c_str (), NULL, 10); |
| 2041 | } |
| 2042 | |
| 2043 | /* Perform operation OP with operands X and Y with sizes LEN_X and LEN_Y |
| 2044 | and byte orders BYTE_ORDER_X and BYTE_ORDER_Y, and store value in |
| 2045 | RESULT with size LEN_RESULT and byte order BYTE_ORDER_RESULT. */ |
| 2046 | void |
| 2047 | decimal_float_ops::binop (enum exp_opcode op, |
| 2048 | const gdb_byte *x, const struct type *type_x, |
| 2049 | const gdb_byte *y, const struct type *type_y, |
| 2050 | gdb_byte *res, const struct type *type_res) const |
| 2051 | { |
| 2052 | decContext set; |
| 2053 | decNumber number1, number2, number3; |
| 2054 | |
| 2055 | decimal_to_number (x, type_x, &number1); |
| 2056 | decimal_to_number (y, type_y, &number2); |
| 2057 | |
| 2058 | set_decnumber_context (&set, type_res); |
| 2059 | |
| 2060 | switch (op) |
| 2061 | { |
| 2062 | case BINOP_ADD: |
| 2063 | decNumberAdd (&number3, &number1, &number2, &set); |
| 2064 | break; |
| 2065 | case BINOP_SUB: |
| 2066 | decNumberSubtract (&number3, &number1, &number2, &set); |
| 2067 | break; |
| 2068 | case BINOP_MUL: |
| 2069 | decNumberMultiply (&number3, &number1, &number2, &set); |
| 2070 | break; |
| 2071 | case BINOP_DIV: |
| 2072 | decNumberDivide (&number3, &number1, &number2, &set); |
| 2073 | break; |
| 2074 | case BINOP_EXP: |
| 2075 | decNumberPower (&number3, &number1, &number2, &set); |
| 2076 | break; |
| 2077 | default: |
| 2078 | error (_("Operation not valid for decimal floating point number.")); |
| 2079 | break; |
| 2080 | } |
| 2081 | |
| 2082 | /* Check for errors in the DFP operation. */ |
| 2083 | decimal_check_errors (&set); |
| 2084 | |
| 2085 | decimal_from_number (&number3, res, type_res); |
| 2086 | } |
| 2087 | |
| 2088 | /* Compares two numbers numerically. If X is less than Y then the return value |
| 2089 | will be -1. If they are equal, then the return value will be 0. If X is |
| 2090 | greater than the Y then the return value will be 1. */ |
| 2091 | int |
| 2092 | decimal_float_ops::compare (const gdb_byte *x, const struct type *type_x, |
| 2093 | const gdb_byte *y, const struct type *type_y) const |
| 2094 | { |
| 2095 | decNumber number1, number2, result; |
| 2096 | decContext set; |
| 2097 | const struct type *type_result; |
| 2098 | |
| 2099 | decimal_to_number (x, type_x, &number1); |
| 2100 | decimal_to_number (y, type_y, &number2); |
| 2101 | |
| 2102 | /* Perform the comparison in the larger of the two sizes. */ |
| 2103 | type_result = TYPE_LENGTH (type_x) > TYPE_LENGTH (type_y) ? type_x : type_y; |
| 2104 | set_decnumber_context (&set, type_result); |
| 2105 | |
| 2106 | decNumberCompare (&result, &number1, &number2, &set); |
| 2107 | |
| 2108 | /* Check for errors in the DFP operation. */ |
| 2109 | decimal_check_errors (&set); |
| 2110 | |
| 2111 | if (decNumberIsNaN (&result)) |
| 2112 | error (_("Comparison with an invalid number (NaN).")); |
| 2113 | else if (decNumberIsZero (&result)) |
| 2114 | return 0; |
| 2115 | else if (decNumberIsNegative (&result)) |
| 2116 | return -1; |
| 2117 | else |
| 2118 | return 1; |
| 2119 | } |
| 2120 | |
| 2121 | /* Convert a decimal value from a decimal type with LEN_FROM bytes to a |
| 2122 | decimal type with LEN_TO bytes. */ |
| 2123 | void |
| 2124 | decimal_float_ops::convert (const gdb_byte *from, const struct type *from_type, |
| 2125 | gdb_byte *to, const struct type *to_type) const |
| 2126 | { |
| 2127 | decNumber number; |
| 2128 | |
| 2129 | decimal_to_number (from, from_type, &number); |
| 2130 | decimal_from_number (&number, to, to_type); |
| 2131 | } |
| 2132 | |
| 2133 | |
| 2134 | /* Typed floating-point routines. These routines operate on floating-point |
| 2135 | values in target format, represented by a byte buffer interpreted as a |
| 2136 | "struct type", which may be either a binary or decimal floating-point |
| 2137 | type (TYPE_CODE_FLT or TYPE_CODE_DECFLOAT). */ |
| 2138 | |
| 2139 | /* Return whether TYPE1 and TYPE2 are of the same category (binary or |
| 2140 | decimal floating-point). */ |
| 2141 | static bool |
| 2142 | target_float_same_category_p (const struct type *type1, |
| 2143 | const struct type *type2) |
| 2144 | { |
| 2145 | return type1->code () == type2->code (); |
| 2146 | } |
| 2147 | |
| 2148 | /* Return whether TYPE1 and TYPE2 use the same floating-point format. */ |
| 2149 | static bool |
| 2150 | target_float_same_format_p (const struct type *type1, |
| 2151 | const struct type *type2) |
| 2152 | { |
| 2153 | if (!target_float_same_category_p (type1, type2)) |
| 2154 | return false; |
| 2155 | |
| 2156 | switch (type1->code ()) |
| 2157 | { |
| 2158 | case TYPE_CODE_FLT: |
| 2159 | return floatformat_from_type (type1) == floatformat_from_type (type2); |
| 2160 | |
| 2161 | case TYPE_CODE_DECFLOAT: |
| 2162 | return (TYPE_LENGTH (type1) == TYPE_LENGTH (type2) |
| 2163 | && (type_byte_order (type1) |
| 2164 | == type_byte_order (type2))); |
| 2165 | |
| 2166 | default: |
| 2167 | gdb_assert_not_reached ("unexpected type code"); |
| 2168 | } |
| 2169 | } |
| 2170 | |
| 2171 | /* Return the size (without padding) of the target floating-point |
| 2172 | format used by TYPE. */ |
| 2173 | static int |
| 2174 | target_float_format_length (const struct type *type) |
| 2175 | { |
| 2176 | switch (type->code ()) |
| 2177 | { |
| 2178 | case TYPE_CODE_FLT: |
| 2179 | return floatformat_totalsize_bytes (floatformat_from_type (type)); |
| 2180 | |
| 2181 | case TYPE_CODE_DECFLOAT: |
| 2182 | return TYPE_LENGTH (type); |
| 2183 | |
| 2184 | default: |
| 2185 | gdb_assert_not_reached ("unexpected type code"); |
| 2186 | } |
| 2187 | } |
| 2188 | |
| 2189 | /* Identifiers of available host-side intermediate formats. These must |
| 2190 | be sorted so the that the more "general" kinds come later. */ |
| 2191 | enum target_float_ops_kind |
| 2192 | { |
| 2193 | /* Target binary floating-point formats that match a host format. */ |
| 2194 | host_float = 0, |
| 2195 | host_double, |
| 2196 | host_long_double, |
| 2197 | /* Any other target binary floating-point format. */ |
| 2198 | binary, |
| 2199 | /* Any target decimal floating-point format. */ |
| 2200 | decimal |
| 2201 | }; |
| 2202 | |
| 2203 | /* Given a target type TYPE, choose the best host-side intermediate format |
| 2204 | to perform operations on TYPE in. */ |
| 2205 | static enum target_float_ops_kind |
| 2206 | get_target_float_ops_kind (const struct type *type) |
| 2207 | { |
| 2208 | switch (type->code ()) |
| 2209 | { |
| 2210 | case TYPE_CODE_FLT: |
| 2211 | { |
| 2212 | const struct floatformat *fmt = floatformat_from_type (type); |
| 2213 | |
| 2214 | /* Binary floating-point formats matching a host format. */ |
| 2215 | if (fmt == host_float_format) |
| 2216 | return target_float_ops_kind::host_float; |
| 2217 | if (fmt == host_double_format) |
| 2218 | return target_float_ops_kind::host_double; |
| 2219 | if (fmt == host_long_double_format) |
| 2220 | return target_float_ops_kind::host_long_double; |
| 2221 | |
| 2222 | /* Any other binary floating-point format. */ |
| 2223 | return target_float_ops_kind::binary; |
| 2224 | } |
| 2225 | |
| 2226 | case TYPE_CODE_DECFLOAT: |
| 2227 | { |
| 2228 | /* Any decimal floating-point format. */ |
| 2229 | return target_float_ops_kind::decimal; |
| 2230 | } |
| 2231 | |
| 2232 | default: |
| 2233 | gdb_assert_not_reached ("unexpected type code"); |
| 2234 | } |
| 2235 | } |
| 2236 | |
| 2237 | /* Return target_float_ops to peform operations for KIND. */ |
| 2238 | static const target_float_ops * |
| 2239 | get_target_float_ops (enum target_float_ops_kind kind) |
| 2240 | { |
| 2241 | switch (kind) |
| 2242 | { |
| 2243 | /* If the type format matches one of the host floating-point |
| 2244 | types, use that type as intermediate format. */ |
| 2245 | case target_float_ops_kind::host_float: |
| 2246 | { |
| 2247 | static host_float_ops<float> host_float_ops_float; |
| 2248 | return &host_float_ops_float; |
| 2249 | } |
| 2250 | |
| 2251 | case target_float_ops_kind::host_double: |
| 2252 | { |
| 2253 | static host_float_ops<double> host_float_ops_double; |
| 2254 | return &host_float_ops_double; |
| 2255 | } |
| 2256 | |
| 2257 | case target_float_ops_kind::host_long_double: |
| 2258 | { |
| 2259 | static host_float_ops<long double> host_float_ops_long_double; |
| 2260 | return &host_float_ops_long_double; |
| 2261 | } |
| 2262 | |
| 2263 | /* For binary floating-point formats that do not match any host format, |
| 2264 | use mpfr_t as intermediate format to provide precise target-floating |
| 2265 | point emulation. However, if the MPFR library is not available, |
| 2266 | use the largest host floating-point type as intermediate format. */ |
| 2267 | case target_float_ops_kind::binary: |
| 2268 | { |
| 2269 | #ifdef HAVE_LIBMPFR |
| 2270 | static mpfr_float_ops binary_float_ops; |
| 2271 | #else |
| 2272 | static host_float_ops<long double> binary_float_ops; |
| 2273 | #endif |
| 2274 | return &binary_float_ops; |
| 2275 | } |
| 2276 | |
| 2277 | /* For decimal floating-point types, always use the libdecnumber |
| 2278 | decNumber type as intermediate format. */ |
| 2279 | case target_float_ops_kind::decimal: |
| 2280 | { |
| 2281 | static decimal_float_ops decimal_float_ops; |
| 2282 | return &decimal_float_ops; |
| 2283 | } |
| 2284 | |
| 2285 | default: |
| 2286 | gdb_assert_not_reached ("unexpected target_float_ops_kind"); |
| 2287 | } |
| 2288 | } |
| 2289 | |
| 2290 | /* Given a target type TYPE, determine the best host-side intermediate format |
| 2291 | to perform operations on TYPE in. */ |
| 2292 | static const target_float_ops * |
| 2293 | get_target_float_ops (const struct type *type) |
| 2294 | { |
| 2295 | enum target_float_ops_kind kind = get_target_float_ops_kind (type); |
| 2296 | return get_target_float_ops (kind); |
| 2297 | } |
| 2298 | |
| 2299 | /* The same for operations involving two target types TYPE1 and TYPE2. */ |
| 2300 | static const target_float_ops * |
| 2301 | get_target_float_ops (const struct type *type1, const struct type *type2) |
| 2302 | { |
| 2303 | gdb_assert (type1->code () == type2->code ()); |
| 2304 | |
| 2305 | enum target_float_ops_kind kind1 = get_target_float_ops_kind (type1); |
| 2306 | enum target_float_ops_kind kind2 = get_target_float_ops_kind (type2); |
| 2307 | |
| 2308 | /* Given the way the kinds are sorted, we simply choose the larger one; |
| 2309 | this will be able to hold values of either type. */ |
| 2310 | return get_target_float_ops (std::max (kind1, kind2)); |
| 2311 | } |
| 2312 | |
| 2313 | /* Return whether the byte-stream ADDR holds a valid value of |
| 2314 | floating-point type TYPE. */ |
| 2315 | bool |
| 2316 | target_float_is_valid (const gdb_byte *addr, const struct type *type) |
| 2317 | { |
| 2318 | if (type->code () == TYPE_CODE_FLT) |
| 2319 | return floatformat_is_valid (floatformat_from_type (type), addr); |
| 2320 | |
| 2321 | if (type->code () == TYPE_CODE_DECFLOAT) |
| 2322 | return true; |
| 2323 | |
| 2324 | gdb_assert_not_reached ("unexpected type code"); |
| 2325 | } |
| 2326 | |
| 2327 | /* Return whether the byte-stream ADDR, interpreted as floating-point |
| 2328 | type TYPE, is numerically equal to zero (of either sign). */ |
| 2329 | bool |
| 2330 | target_float_is_zero (const gdb_byte *addr, const struct type *type) |
| 2331 | { |
| 2332 | if (type->code () == TYPE_CODE_FLT) |
| 2333 | return (floatformat_classify (floatformat_from_type (type), addr) |
| 2334 | == float_zero); |
| 2335 | |
| 2336 | if (type->code () == TYPE_CODE_DECFLOAT) |
| 2337 | return decimal_is_zero (addr, type); |
| 2338 | |
| 2339 | gdb_assert_not_reached ("unexpected type code"); |
| 2340 | } |
| 2341 | |
| 2342 | /* Convert the byte-stream ADDR, interpreted as floating-point type TYPE, |
| 2343 | to a string, optionally using the print format FORMAT. */ |
| 2344 | std::string |
| 2345 | target_float_to_string (const gdb_byte *addr, const struct type *type, |
| 2346 | const char *format) |
| 2347 | { |
| 2348 | /* Unless we need to adhere to a specific format, provide special |
| 2349 | output for special cases of binary floating-point numbers. */ |
| 2350 | if (format == nullptr && type->code () == TYPE_CODE_FLT) |
| 2351 | { |
| 2352 | const struct floatformat *fmt = floatformat_from_type (type); |
| 2353 | |
| 2354 | /* Detect invalid representations. */ |
| 2355 | if (!floatformat_is_valid (fmt, addr)) |
| 2356 | return "<invalid float value>"; |
| 2357 | |
| 2358 | /* Handle NaN and Inf. */ |
| 2359 | enum float_kind kind = floatformat_classify (fmt, addr); |
| 2360 | if (kind == float_nan) |
| 2361 | { |
| 2362 | const char *sign = floatformat_is_negative (fmt, addr)? "-" : ""; |
| 2363 | const char *mantissa = floatformat_mantissa (fmt, addr); |
| 2364 | return string_printf ("%snan(0x%s)", sign, mantissa); |
| 2365 | } |
| 2366 | else if (kind == float_infinite) |
| 2367 | { |
| 2368 | const char *sign = floatformat_is_negative (fmt, addr)? "-" : ""; |
| 2369 | return string_printf ("%sinf", sign); |
| 2370 | } |
| 2371 | } |
| 2372 | |
| 2373 | const target_float_ops *ops = get_target_float_ops (type); |
| 2374 | return ops->to_string (addr, type, format); |
| 2375 | } |
| 2376 | |
| 2377 | /* Parse string STRING into a target floating-number of type TYPE and |
| 2378 | store it as byte-stream ADDR. Return whether parsing succeeded. */ |
| 2379 | bool |
| 2380 | target_float_from_string (gdb_byte *addr, const struct type *type, |
| 2381 | const std::string &string) |
| 2382 | { |
| 2383 | const target_float_ops *ops = get_target_float_ops (type); |
| 2384 | return ops->from_string (addr, type, string); |
| 2385 | } |
| 2386 | |
| 2387 | /* Convert the byte-stream ADDR, interpreted as floating-point type TYPE, |
| 2388 | to an integer value (rounding towards zero). */ |
| 2389 | LONGEST |
| 2390 | target_float_to_longest (const gdb_byte *addr, const struct type *type) |
| 2391 | { |
| 2392 | const target_float_ops *ops = get_target_float_ops (type); |
| 2393 | return ops->to_longest (addr, type); |
| 2394 | } |
| 2395 | |
| 2396 | /* Convert signed integer VAL to a target floating-number of type TYPE |
| 2397 | and store it as byte-stream ADDR. */ |
| 2398 | void |
| 2399 | target_float_from_longest (gdb_byte *addr, const struct type *type, |
| 2400 | LONGEST val) |
| 2401 | { |
| 2402 | const target_float_ops *ops = get_target_float_ops (type); |
| 2403 | ops->from_longest (addr, type, val); |
| 2404 | } |
| 2405 | |
| 2406 | /* Convert unsigned integer VAL to a target floating-number of type TYPE |
| 2407 | and store it as byte-stream ADDR. */ |
| 2408 | void |
| 2409 | target_float_from_ulongest (gdb_byte *addr, const struct type *type, |
| 2410 | ULONGEST val) |
| 2411 | { |
| 2412 | const target_float_ops *ops = get_target_float_ops (type); |
| 2413 | ops->from_ulongest (addr, type, val); |
| 2414 | } |
| 2415 | |
| 2416 | /* Convert the byte-stream ADDR, interpreted as floating-point type TYPE, |
| 2417 | to a floating-point value in the host "double" format. */ |
| 2418 | double |
| 2419 | target_float_to_host_double (const gdb_byte *addr, |
| 2420 | const struct type *type) |
| 2421 | { |
| 2422 | const target_float_ops *ops = get_target_float_ops (type); |
| 2423 | return ops->to_host_double (addr, type); |
| 2424 | } |
| 2425 | |
| 2426 | /* Convert floating-point value VAL in the host "double" format to a target |
| 2427 | floating-number of type TYPE and store it as byte-stream ADDR. */ |
| 2428 | void |
| 2429 | target_float_from_host_double (gdb_byte *addr, const struct type *type, |
| 2430 | double val) |
| 2431 | { |
| 2432 | const target_float_ops *ops = get_target_float_ops (type); |
| 2433 | ops->from_host_double (addr, type, val); |
| 2434 | } |
| 2435 | |
| 2436 | /* Convert a floating-point number of type FROM_TYPE from the target |
| 2437 | byte-stream FROM to a floating-point number of type TO_TYPE, and |
| 2438 | store it to the target byte-stream TO. */ |
| 2439 | void |
| 2440 | target_float_convert (const gdb_byte *from, const struct type *from_type, |
| 2441 | gdb_byte *to, const struct type *to_type) |
| 2442 | { |
| 2443 | /* We cannot directly convert between binary and decimal floating-point |
| 2444 | types, so go via an intermediary string. */ |
| 2445 | if (!target_float_same_category_p (from_type, to_type)) |
| 2446 | { |
| 2447 | std::string str = target_float_to_string (from, from_type); |
| 2448 | target_float_from_string (to, to_type, str); |
| 2449 | return; |
| 2450 | } |
| 2451 | |
| 2452 | /* Convert between two different formats in the same category. */ |
| 2453 | if (!target_float_same_format_p (from_type, to_type)) |
| 2454 | { |
| 2455 | const target_float_ops *ops = get_target_float_ops (from_type, to_type); |
| 2456 | ops->convert (from, from_type, to, to_type); |
| 2457 | return; |
| 2458 | } |
| 2459 | |
| 2460 | /* The floating-point formats match, so we simply copy the data, ensuring |
| 2461 | possible padding bytes in the target buffer are zeroed out. */ |
| 2462 | memset (to, 0, TYPE_LENGTH (to_type)); |
| 2463 | memcpy (to, from, target_float_format_length (to_type)); |
| 2464 | } |
| 2465 | |
| 2466 | /* Perform the binary operation indicated by OPCODE, using as operands the |
| 2467 | target byte streams X and Y, interpreted as floating-point numbers of |
| 2468 | types TYPE_X and TYPE_Y, respectively. Convert the result to type |
| 2469 | TYPE_RES and store it into the byte-stream RES. |
| 2470 | |
| 2471 | The three types must either be all binary floating-point types, or else |
| 2472 | all decimal floating-point types. Binary and decimal floating-point |
| 2473 | types cannot be mixed within a single operation. */ |
| 2474 | void |
| 2475 | target_float_binop (enum exp_opcode opcode, |
| 2476 | const gdb_byte *x, const struct type *type_x, |
| 2477 | const gdb_byte *y, const struct type *type_y, |
| 2478 | gdb_byte *res, const struct type *type_res) |
| 2479 | { |
| 2480 | gdb_assert (target_float_same_category_p (type_x, type_res)); |
| 2481 | gdb_assert (target_float_same_category_p (type_y, type_res)); |
| 2482 | |
| 2483 | const target_float_ops *ops = get_target_float_ops (type_x, type_y); |
| 2484 | ops->binop (opcode, x, type_x, y, type_y, res, type_res); |
| 2485 | } |
| 2486 | |
| 2487 | /* Compare the two target byte streams X and Y, interpreted as floating-point |
| 2488 | numbers of types TYPE_X and TYPE_Y, respectively. Return zero if X and Y |
| 2489 | are equal, -1 if X is less than Y, and 1 otherwise. |
| 2490 | |
| 2491 | The two types must either both be binary floating-point types, or else |
| 2492 | both be decimal floating-point types. Binary and decimal floating-point |
| 2493 | types cannot compared directly against each other. */ |
| 2494 | int |
| 2495 | target_float_compare (const gdb_byte *x, const struct type *type_x, |
| 2496 | const gdb_byte *y, const struct type *type_y) |
| 2497 | { |
| 2498 | gdb_assert (target_float_same_category_p (type_x, type_y)); |
| 2499 | |
| 2500 | const target_float_ops *ops = get_target_float_ops (type_x, type_y); |
| 2501 | return ops->compare (x, type_x, y, type_y); |
| 2502 | } |
| 2503 | |