| 1 | /* Intel 387 floating point stuff. |
| 2 | Copyright 1988, 1989, 1991, 1992, 1993, 1994, 1998, 1999, 2000, |
| 3 | 2001, 2002 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 2 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, write to the Free Software |
| 19 | Foundation, Inc., 59 Temple Place - Suite 330, |
| 20 | Boston, MA 02111-1307, USA. */ |
| 21 | |
| 22 | #include "defs.h" |
| 23 | #include "frame.h" |
| 24 | #include "inferior.h" |
| 25 | #include "language.h" |
| 26 | #include "value.h" |
| 27 | #include "gdbcore.h" |
| 28 | #include "floatformat.h" |
| 29 | #include "regcache.h" |
| 30 | #include "gdb_assert.h" |
| 31 | #include "doublest.h" |
| 32 | |
| 33 | #include "i386-tdep.h" |
| 34 | |
| 35 | /* FIXME: Eliminate the next two functions when we have the time to |
| 36 | change all the callers. */ |
| 37 | |
| 38 | void i387_to_double (char *from, char *to); |
| 39 | void double_to_i387 (char *from, char *to); |
| 40 | |
| 41 | void |
| 42 | i387_to_double (char *from, char *to) |
| 43 | { |
| 44 | floatformat_to_double (&floatformat_i387_ext, from, (double *) to); |
| 45 | } |
| 46 | |
| 47 | void |
| 48 | double_to_i387 (char *from, char *to) |
| 49 | { |
| 50 | floatformat_from_double (&floatformat_i387_ext, (double *) from, to); |
| 51 | } |
| 52 | |
| 53 | \f |
| 54 | /* FIXME: The functions on this page are used by the old `info float' |
| 55 | implementations that a few of the i386 targets provide. These |
| 56 | functions should be removed if all of these have been converted to |
| 57 | use the generic implementation based on the new register file |
| 58 | layout. */ |
| 59 | |
| 60 | static void print_387_control_bits (unsigned int control); |
| 61 | static void print_387_status_bits (unsigned int status); |
| 62 | |
| 63 | static void |
| 64 | print_387_control_bits (unsigned int control) |
| 65 | { |
| 66 | switch ((control >> 8) & 3) |
| 67 | { |
| 68 | case 0: |
| 69 | puts_unfiltered (" 24 bit; "); |
| 70 | break; |
| 71 | case 1: |
| 72 | puts_unfiltered (" (bad); "); |
| 73 | break; |
| 74 | case 2: |
| 75 | puts_unfiltered (" 53 bit; "); |
| 76 | break; |
| 77 | case 3: |
| 78 | puts_unfiltered (" 64 bit; "); |
| 79 | break; |
| 80 | } |
| 81 | switch ((control >> 10) & 3) |
| 82 | { |
| 83 | case 0: |
| 84 | puts_unfiltered ("NEAR; "); |
| 85 | break; |
| 86 | case 1: |
| 87 | puts_unfiltered ("DOWN; "); |
| 88 | break; |
| 89 | case 2: |
| 90 | puts_unfiltered ("UP; "); |
| 91 | break; |
| 92 | case 3: |
| 93 | puts_unfiltered ("CHOP; "); |
| 94 | break; |
| 95 | } |
| 96 | if (control & 0x3f) |
| 97 | { |
| 98 | puts_unfiltered ("mask"); |
| 99 | if (control & 0x0001) |
| 100 | puts_unfiltered (" INVAL"); |
| 101 | if (control & 0x0002) |
| 102 | puts_unfiltered (" DENOR"); |
| 103 | if (control & 0x0004) |
| 104 | puts_unfiltered (" DIVZ"); |
| 105 | if (control & 0x0008) |
| 106 | puts_unfiltered (" OVERF"); |
| 107 | if (control & 0x0010) |
| 108 | puts_unfiltered (" UNDER"); |
| 109 | if (control & 0x0020) |
| 110 | puts_unfiltered (" LOS"); |
| 111 | puts_unfiltered (";"); |
| 112 | } |
| 113 | |
| 114 | if (control & 0xe080) |
| 115 | warning ("\nreserved bits on: %s", |
| 116 | local_hex_string (control & 0xe080)); |
| 117 | } |
| 118 | |
| 119 | void |
| 120 | print_387_control_word (unsigned int control) |
| 121 | { |
| 122 | printf_filtered ("control %s:", local_hex_string(control & 0xffff)); |
| 123 | print_387_control_bits (control); |
| 124 | puts_unfiltered ("\n"); |
| 125 | } |
| 126 | |
| 127 | static void |
| 128 | print_387_status_bits (unsigned int status) |
| 129 | { |
| 130 | printf_unfiltered (" flags %d%d%d%d; ", |
| 131 | (status & 0x4000) != 0, |
| 132 | (status & 0x0400) != 0, |
| 133 | (status & 0x0200) != 0, |
| 134 | (status & 0x0100) != 0); |
| 135 | printf_unfiltered ("top %d; ", (status >> 11) & 7); |
| 136 | if (status & 0xff) |
| 137 | { |
| 138 | puts_unfiltered ("excep"); |
| 139 | if (status & 0x0001) puts_unfiltered (" INVAL"); |
| 140 | if (status & 0x0002) puts_unfiltered (" DENOR"); |
| 141 | if (status & 0x0004) puts_unfiltered (" DIVZ"); |
| 142 | if (status & 0x0008) puts_unfiltered (" OVERF"); |
| 143 | if (status & 0x0010) puts_unfiltered (" UNDER"); |
| 144 | if (status & 0x0020) puts_unfiltered (" LOS"); |
| 145 | if (status & 0x0040) puts_unfiltered (" STACK"); |
| 146 | } |
| 147 | } |
| 148 | |
| 149 | void |
| 150 | print_387_status_word (unsigned int status) |
| 151 | { |
| 152 | printf_filtered ("status %s:", local_hex_string (status & 0xffff)); |
| 153 | print_387_status_bits (status); |
| 154 | puts_unfiltered ("\n"); |
| 155 | } |
| 156 | |
| 157 | \f |
| 158 | /* Implement the `info float' layout based on the register definitions |
| 159 | in `tm-i386.h'. */ |
| 160 | |
| 161 | /* Print the floating point number specified by RAW. */ |
| 162 | static void |
| 163 | print_i387_value (char *raw) |
| 164 | { |
| 165 | DOUBLEST value; |
| 166 | |
| 167 | /* Using extract_typed_floating here might affect the representation |
| 168 | of certain numbers such as NaNs, even if GDB is running natively. |
| 169 | This is fine since our caller already detects such special |
| 170 | numbers and we print the hexadecimal representation anyway. */ |
| 171 | value = extract_typed_floating (raw, builtin_type_i387_ext); |
| 172 | |
| 173 | /* We try to print 19 digits. The last digit may or may not contain |
| 174 | garbage, but we'd better print one too many. We need enough room |
| 175 | to print the value, 1 position for the sign, 1 for the decimal |
| 176 | point, 19 for the digits and 6 for the exponent adds up to 27. */ |
| 177 | #ifdef PRINTF_HAS_LONG_DOUBLE |
| 178 | printf_filtered (" %-+27.19Lg", (long double) value); |
| 179 | #else |
| 180 | printf_filtered (" %-+27.19g", (double) value); |
| 181 | #endif |
| 182 | } |
| 183 | |
| 184 | /* Print the classification for the register contents RAW. */ |
| 185 | static void |
| 186 | print_i387_ext (unsigned char *raw) |
| 187 | { |
| 188 | int sign; |
| 189 | int integer; |
| 190 | unsigned int exponent; |
| 191 | unsigned long fraction[2]; |
| 192 | |
| 193 | sign = raw[9] & 0x80; |
| 194 | integer = raw[7] & 0x80; |
| 195 | exponent = (((raw[9] & 0x7f) << 8) | raw[8]); |
| 196 | fraction[0] = ((raw[3] << 24) | (raw[2] << 16) | (raw[1] << 8) | raw[0]); |
| 197 | fraction[1] = (((raw[7] & 0x7f) << 24) | (raw[6] << 16) |
| 198 | | (raw[5] << 8) | raw[4]); |
| 199 | |
| 200 | if (exponent == 0x7fff && integer) |
| 201 | { |
| 202 | if (fraction[0] == 0x00000000 && fraction[1] == 0x00000000) |
| 203 | /* Infinity. */ |
| 204 | printf_filtered (" %cInf", (sign ? '-' : '+')); |
| 205 | else if (sign && fraction[0] == 0x00000000 && fraction[1] == 0x40000000) |
| 206 | /* Real Indefinite (QNaN). */ |
| 207 | puts_unfiltered (" Real Indefinite (QNaN)"); |
| 208 | else if (fraction[1] & 0x40000000) |
| 209 | /* QNaN. */ |
| 210 | puts_filtered (" QNaN"); |
| 211 | else |
| 212 | /* SNaN. */ |
| 213 | puts_filtered (" SNaN"); |
| 214 | } |
| 215 | else if (exponent < 0x7fff && exponent > 0x0000 && integer) |
| 216 | /* Normal. */ |
| 217 | print_i387_value (raw); |
| 218 | else if (exponent == 0x0000) |
| 219 | { |
| 220 | /* Denormal or zero. */ |
| 221 | print_i387_value (raw); |
| 222 | |
| 223 | if (integer) |
| 224 | /* Pseudo-denormal. */ |
| 225 | puts_filtered (" Pseudo-denormal"); |
| 226 | else if (fraction[0] || fraction[1]) |
| 227 | /* Denormal. */ |
| 228 | puts_filtered (" Denormal"); |
| 229 | } |
| 230 | else |
| 231 | /* Unsupported. */ |
| 232 | puts_filtered (" Unsupported"); |
| 233 | } |
| 234 | |
| 235 | /* Print the status word STATUS. */ |
| 236 | static void |
| 237 | print_i387_status_word (unsigned int status) |
| 238 | { |
| 239 | printf_filtered ("Status Word: %s", |
| 240 | local_hex_string_custom (status, "04")); |
| 241 | puts_filtered (" "); |
| 242 | printf_filtered (" %s", (status & 0x0001) ? "IE" : " "); |
| 243 | printf_filtered (" %s", (status & 0x0002) ? "DE" : " "); |
| 244 | printf_filtered (" %s", (status & 0x0004) ? "ZE" : " "); |
| 245 | printf_filtered (" %s", (status & 0x0008) ? "OE" : " "); |
| 246 | printf_filtered (" %s", (status & 0x0010) ? "UE" : " "); |
| 247 | printf_filtered (" %s", (status & 0x0020) ? "PE" : " "); |
| 248 | puts_filtered (" "); |
| 249 | printf_filtered (" %s", (status & 0x0080) ? "ES" : " "); |
| 250 | puts_filtered (" "); |
| 251 | printf_filtered (" %s", (status & 0x0040) ? "SF" : " "); |
| 252 | puts_filtered (" "); |
| 253 | printf_filtered (" %s", (status & 0x0100) ? "C0" : " "); |
| 254 | printf_filtered (" %s", (status & 0x0200) ? "C1" : " "); |
| 255 | printf_filtered (" %s", (status & 0x0400) ? "C2" : " "); |
| 256 | printf_filtered (" %s", (status & 0x4000) ? "C3" : " "); |
| 257 | |
| 258 | puts_filtered ("\n"); |
| 259 | |
| 260 | printf_filtered (" TOP: %d\n", ((status >> 11) & 7)); |
| 261 | } |
| 262 | |
| 263 | /* Print the control word CONTROL. */ |
| 264 | static void |
| 265 | print_i387_control_word (unsigned int control) |
| 266 | { |
| 267 | printf_filtered ("Control Word: %s", |
| 268 | local_hex_string_custom (control, "04")); |
| 269 | puts_filtered (" "); |
| 270 | printf_filtered (" %s", (control & 0x0001) ? "IM" : " "); |
| 271 | printf_filtered (" %s", (control & 0x0002) ? "DM" : " "); |
| 272 | printf_filtered (" %s", (control & 0x0004) ? "ZM" : " "); |
| 273 | printf_filtered (" %s", (control & 0x0008) ? "OM" : " "); |
| 274 | printf_filtered (" %s", (control & 0x0010) ? "UM" : " "); |
| 275 | printf_filtered (" %s", (control & 0x0020) ? "PM" : " "); |
| 276 | |
| 277 | puts_filtered ("\n"); |
| 278 | |
| 279 | puts_filtered (" PC: "); |
| 280 | switch ((control >> 8) & 3) |
| 281 | { |
| 282 | case 0: |
| 283 | puts_filtered ("Single Precision (24-bits)\n"); |
| 284 | break; |
| 285 | case 1: |
| 286 | puts_filtered ("Reserved\n"); |
| 287 | break; |
| 288 | case 2: |
| 289 | puts_filtered ("Double Precision (53-bits)\n"); |
| 290 | break; |
| 291 | case 3: |
| 292 | puts_filtered ("Extended Precision (64-bits)\n"); |
| 293 | break; |
| 294 | } |
| 295 | |
| 296 | puts_filtered (" RC: "); |
| 297 | switch ((control >> 10) & 3) |
| 298 | { |
| 299 | case 0: |
| 300 | puts_filtered ("Round to nearest\n"); |
| 301 | break; |
| 302 | case 1: |
| 303 | puts_filtered ("Round down\n"); |
| 304 | break; |
| 305 | case 2: |
| 306 | puts_filtered ("Round up\n"); |
| 307 | break; |
| 308 | case 3: |
| 309 | puts_filtered ("Round toward zero\n"); |
| 310 | break; |
| 311 | } |
| 312 | } |
| 313 | |
| 314 | /* Print out the i387 floating poin state. */ |
| 315 | void |
| 316 | i387_float_info (void) |
| 317 | { |
| 318 | unsigned int fctrl; |
| 319 | unsigned int fstat; |
| 320 | unsigned int ftag; |
| 321 | unsigned int fiseg; |
| 322 | unsigned int fioff; |
| 323 | unsigned int foseg; |
| 324 | unsigned int fooff; |
| 325 | unsigned int fop; |
| 326 | int fpreg; |
| 327 | int top; |
| 328 | |
| 329 | fctrl = read_register (FCTRL_REGNUM); |
| 330 | fstat = read_register (FSTAT_REGNUM); |
| 331 | ftag = read_register (FTAG_REGNUM); |
| 332 | fiseg = read_register (FCS_REGNUM); |
| 333 | fioff = read_register (FCOFF_REGNUM); |
| 334 | foseg = read_register (FDS_REGNUM); |
| 335 | fooff = read_register (FDOFF_REGNUM); |
| 336 | fop = read_register (FOP_REGNUM); |
| 337 | |
| 338 | top = ((fstat >> 11) & 7); |
| 339 | |
| 340 | for (fpreg = 7; fpreg >= 0; fpreg--) |
| 341 | { |
| 342 | unsigned char raw[FPU_REG_RAW_SIZE]; |
| 343 | int tag = (ftag >> (fpreg * 2)) & 3; |
| 344 | int i; |
| 345 | |
| 346 | printf_filtered ("%sR%d: ", fpreg == top ? "=>" : " ", fpreg); |
| 347 | |
| 348 | switch (tag) |
| 349 | { |
| 350 | case 0: |
| 351 | puts_filtered ("Valid "); |
| 352 | break; |
| 353 | case 1: |
| 354 | puts_filtered ("Zero "); |
| 355 | break; |
| 356 | case 2: |
| 357 | puts_filtered ("Special "); |
| 358 | break; |
| 359 | case 3: |
| 360 | puts_filtered ("Empty "); |
| 361 | break; |
| 362 | } |
| 363 | |
| 364 | read_register_gen ((fpreg + 8 - top) % 8 + FP0_REGNUM, raw); |
| 365 | |
| 366 | puts_filtered ("0x"); |
| 367 | for (i = 9; i >= 0; i--) |
| 368 | printf_filtered ("%02x", raw[i]); |
| 369 | |
| 370 | if (tag != 3) |
| 371 | print_i387_ext (raw); |
| 372 | |
| 373 | puts_filtered ("\n"); |
| 374 | } |
| 375 | |
| 376 | puts_filtered ("\n"); |
| 377 | |
| 378 | print_i387_status_word (fstat); |
| 379 | print_i387_control_word (fctrl); |
| 380 | printf_filtered ("Tag Word: %s\n", |
| 381 | local_hex_string_custom (ftag, "04")); |
| 382 | printf_filtered ("Instruction Pointer: %s:", |
| 383 | local_hex_string_custom (fiseg, "02")); |
| 384 | printf_filtered ("%s\n", local_hex_string_custom (fioff, "08")); |
| 385 | printf_filtered ("Operand Pointer: %s:", |
| 386 | local_hex_string_custom (foseg, "02")); |
| 387 | printf_filtered ("%s\n", local_hex_string_custom (fooff, "08")); |
| 388 | printf_filtered ("Opcode: %s\n", |
| 389 | local_hex_string_custom (fop ? (fop | 0xd800) : 0, "04")); |
| 390 | } |
| 391 | |
| 392 | /* FIXME: kettenis/2000-05-21: Right now more than a few i386 targets |
| 393 | define their own routines to manage the floating-point registers in |
| 394 | GDB's register array. Most (if not all) of these targets use the |
| 395 | format used by the "fsave" instruction in their communication with |
| 396 | the OS. They should all be converted to use the routines below. */ |
| 397 | |
| 398 | /* At fsave_offset[REGNUM] you'll find the offset to the location in |
| 399 | the data structure used by the "fsave" instruction where GDB |
| 400 | register REGNUM is stored. */ |
| 401 | |
| 402 | static int fsave_offset[] = |
| 403 | { |
| 404 | 28 + 0 * FPU_REG_RAW_SIZE, /* FP0_REGNUM through ... */ |
| 405 | 28 + 1 * FPU_REG_RAW_SIZE, |
| 406 | 28 + 2 * FPU_REG_RAW_SIZE, |
| 407 | 28 + 3 * FPU_REG_RAW_SIZE, |
| 408 | 28 + 4 * FPU_REG_RAW_SIZE, |
| 409 | 28 + 5 * FPU_REG_RAW_SIZE, |
| 410 | 28 + 6 * FPU_REG_RAW_SIZE, |
| 411 | 28 + 7 * FPU_REG_RAW_SIZE, /* ... FP7_REGNUM. */ |
| 412 | 0, /* FCTRL_REGNUM (16 bits). */ |
| 413 | 4, /* FSTAT_REGNUM (16 bits). */ |
| 414 | 8, /* FTAG_REGNUM (16 bits). */ |
| 415 | 16, /* FISEG_REGNUM (16 bits). */ |
| 416 | 12, /* FIOFF_REGNUM. */ |
| 417 | 24, /* FOSEG_REGNUM. */ |
| 418 | 20, /* FOOFF_REGNUM. */ |
| 419 | 18 /* FOP_REGNUM (bottom 11 bits). */ |
| 420 | }; |
| 421 | |
| 422 | #define FSAVE_ADDR(fsave, regnum) (fsave + fsave_offset[regnum - FP0_REGNUM]) |
| 423 | \f |
| 424 | |
| 425 | /* Fill register REGNUM in GDB's register array with the appropriate |
| 426 | value from *FSAVE. This function masks off any of the reserved |
| 427 | bits in *FSAVE. */ |
| 428 | |
| 429 | void |
| 430 | i387_supply_register (int regnum, char *fsave) |
| 431 | { |
| 432 | /* Most of the FPU control registers occupy only 16 bits in |
| 433 | the fsave area. Give those a special treatment. */ |
| 434 | if (regnum >= FPC_REGNUM |
| 435 | && regnum != FIOFF_REGNUM && regnum != FOOFF_REGNUM) |
| 436 | { |
| 437 | unsigned char val[4]; |
| 438 | |
| 439 | memcpy (val, FSAVE_ADDR (fsave, regnum), 2); |
| 440 | val[2] = val[3] = 0; |
| 441 | if (regnum == FOP_REGNUM) |
| 442 | val[1] &= ((1 << 3) - 1); |
| 443 | supply_register (regnum, val); |
| 444 | } |
| 445 | else |
| 446 | supply_register (regnum, FSAVE_ADDR (fsave, regnum)); |
| 447 | } |
| 448 | |
| 449 | /* Fill GDB's register array with the floating-point register values |
| 450 | in *FSAVE. This function masks off any of the reserved |
| 451 | bits in *FSAVE. */ |
| 452 | |
| 453 | void |
| 454 | i387_supply_fsave (char *fsave) |
| 455 | { |
| 456 | int i; |
| 457 | |
| 458 | for (i = FP0_REGNUM; i < XMM0_REGNUM; i++) |
| 459 | i387_supply_register (i, fsave); |
| 460 | } |
| 461 | |
| 462 | /* Fill register REGNUM (if it is a floating-point register) in *FSAVE |
| 463 | with the value in GDB's register array. If REGNUM is -1, do this |
| 464 | for all registers. This function doesn't touch any of the reserved |
| 465 | bits in *FSAVE. */ |
| 466 | |
| 467 | void |
| 468 | i387_fill_fsave (char *fsave, int regnum) |
| 469 | { |
| 470 | int i; |
| 471 | |
| 472 | for (i = FP0_REGNUM; i < XMM0_REGNUM; i++) |
| 473 | if (regnum == -1 || regnum == i) |
| 474 | { |
| 475 | /* Most of the FPU control registers occupy only 16 bits in |
| 476 | the fsave area. Give those a special treatment. */ |
| 477 | if (i >= FPC_REGNUM |
| 478 | && i != FIOFF_REGNUM && i != FOOFF_REGNUM) |
| 479 | { |
| 480 | unsigned char buf[4]; |
| 481 | |
| 482 | regcache_collect (i, buf); |
| 483 | |
| 484 | if (i == FOP_REGNUM) |
| 485 | { |
| 486 | /* The opcode occupies only 11 bits. Make sure we |
| 487 | don't touch the other bits. */ |
| 488 | buf[1] &= ((1 << 3) - 1); |
| 489 | buf[1] |= ((FSAVE_ADDR (fsave, i))[1] & ~((1 << 3) - 1)); |
| 490 | } |
| 491 | memcpy (FSAVE_ADDR (fsave, i), buf, 2); |
| 492 | } |
| 493 | else |
| 494 | regcache_collect (i, FSAVE_ADDR (fsave, i)); |
| 495 | } |
| 496 | } |
| 497 | \f |
| 498 | |
| 499 | /* At fxsave_offset[REGNUM] you'll find the offset to the location in |
| 500 | the data structure used by the "fxsave" instruction where GDB |
| 501 | register REGNUM is stored. */ |
| 502 | |
| 503 | static int fxsave_offset[] = |
| 504 | { |
| 505 | 32, /* FP0_REGNUM through ... */ |
| 506 | 48, |
| 507 | 64, |
| 508 | 80, |
| 509 | 96, |
| 510 | 112, |
| 511 | 128, |
| 512 | 144, /* ... FP7_REGNUM (80 bits each). */ |
| 513 | 0, /* FCTRL_REGNUM (16 bits). */ |
| 514 | 2, /* FSTAT_REGNUM (16 bits). */ |
| 515 | 4, /* FTAG_REGNUM (16 bits). */ |
| 516 | 12, /* FISEG_REGNUM (16 bits). */ |
| 517 | 8, /* FIOFF_REGNUM. */ |
| 518 | 20, /* FOSEG_REGNUM (16 bits). */ |
| 519 | 16, /* FOOFF_REGNUM. */ |
| 520 | 6, /* FOP_REGNUM (bottom 11 bits). */ |
| 521 | 160, /* XMM0_REGNUM through ... */ |
| 522 | 176, |
| 523 | 192, |
| 524 | 208, |
| 525 | 224, |
| 526 | 240, |
| 527 | 256, |
| 528 | 272, /* ... XMM7_REGNUM (128 bits each). */ |
| 529 | 24, /* MXCSR_REGNUM. */ |
| 530 | }; |
| 531 | |
| 532 | #define FXSAVE_ADDR(fxsave, regnum) \ |
| 533 | (fxsave + fxsave_offset[regnum - FP0_REGNUM]) |
| 534 | |
| 535 | static int i387_tag (unsigned char *raw); |
| 536 | \f |
| 537 | |
| 538 | /* Fill GDB's register array with the floating-point and SSE register |
| 539 | values in *FXSAVE. This function masks off any of the reserved |
| 540 | bits in *FXSAVE. */ |
| 541 | |
| 542 | void |
| 543 | i387_supply_fxsave (char *fxsave) |
| 544 | { |
| 545 | int i, last_regnum = MXCSR_REGNUM; |
| 546 | |
| 547 | if (gdbarch_tdep (current_gdbarch)->num_xmm_regs == 0) |
| 548 | last_regnum = FOP_REGNUM; |
| 549 | |
| 550 | for (i = FP0_REGNUM; i <= last_regnum; i++) |
| 551 | { |
| 552 | /* Most of the FPU control registers occupy only 16 bits in |
| 553 | the fxsave area. Give those a special treatment. */ |
| 554 | if (i >= FPC_REGNUM && i < XMM0_REGNUM |
| 555 | && i != FIOFF_REGNUM && i != FOOFF_REGNUM) |
| 556 | { |
| 557 | unsigned char val[4]; |
| 558 | |
| 559 | memcpy (val, FXSAVE_ADDR (fxsave, i), 2); |
| 560 | val[2] = val[3] = 0; |
| 561 | if (i == FOP_REGNUM) |
| 562 | val[1] &= ((1 << 3) - 1); |
| 563 | else if (i== FTAG_REGNUM) |
| 564 | { |
| 565 | /* The fxsave area contains a simplified version of the |
| 566 | tag word. We have to look at the actual 80-bit FP |
| 567 | data to recreate the traditional i387 tag word. */ |
| 568 | |
| 569 | unsigned long ftag = 0; |
| 570 | int fpreg; |
| 571 | int top; |
| 572 | |
| 573 | top = (((FXSAVE_ADDR (fxsave, FSTAT_REGNUM))[1] >> 3) & 0x7); |
| 574 | |
| 575 | for (fpreg = 7; fpreg >= 0; fpreg--) |
| 576 | { |
| 577 | int tag; |
| 578 | |
| 579 | if (val[0] & (1 << fpreg)) |
| 580 | { |
| 581 | int regnum = (fpreg + 8 - top) % 8 + FP0_REGNUM; |
| 582 | tag = i387_tag (FXSAVE_ADDR (fxsave, regnum)); |
| 583 | } |
| 584 | else |
| 585 | tag = 3; /* Empty */ |
| 586 | |
| 587 | ftag |= tag << (2 * fpreg); |
| 588 | } |
| 589 | val[0] = ftag & 0xff; |
| 590 | val[1] = (ftag >> 8) & 0xff; |
| 591 | } |
| 592 | supply_register (i, val); |
| 593 | } |
| 594 | else |
| 595 | supply_register (i, FXSAVE_ADDR (fxsave, i)); |
| 596 | } |
| 597 | } |
| 598 | |
| 599 | /* Fill register REGNUM (if it is a floating-point or SSE register) in |
| 600 | *FXSAVE with the value in GDB's register array. If REGNUM is -1, do |
| 601 | this for all registers. This function doesn't touch any of the |
| 602 | reserved bits in *FXSAVE. */ |
| 603 | |
| 604 | void |
| 605 | i387_fill_fxsave (char *fxsave, int regnum) |
| 606 | { |
| 607 | int i, last_regnum = MXCSR_REGNUM; |
| 608 | |
| 609 | if (gdbarch_tdep (current_gdbarch)->num_xmm_regs == 0) |
| 610 | last_regnum = FOP_REGNUM; |
| 611 | |
| 612 | for (i = FP0_REGNUM; i <= last_regnum; i++) |
| 613 | if (regnum == -1 || regnum == i) |
| 614 | { |
| 615 | /* Most of the FPU control registers occupy only 16 bits in |
| 616 | the fxsave area. Give those a special treatment. */ |
| 617 | if (i >= FPC_REGNUM && i < XMM0_REGNUM |
| 618 | && i != FIOFF_REGNUM && i != FDOFF_REGNUM) |
| 619 | { |
| 620 | unsigned char buf[4]; |
| 621 | |
| 622 | regcache_collect (i, buf); |
| 623 | |
| 624 | if (i == FOP_REGNUM) |
| 625 | { |
| 626 | /* The opcode occupies only 11 bits. Make sure we |
| 627 | don't touch the other bits. */ |
| 628 | buf[1] &= ((1 << 3) - 1); |
| 629 | buf[1] |= ((FXSAVE_ADDR (fxsave, i))[1] & ~((1 << 3) - 1)); |
| 630 | } |
| 631 | else if (i == FTAG_REGNUM) |
| 632 | { |
| 633 | /* Converting back is much easier. */ |
| 634 | |
| 635 | unsigned short ftag; |
| 636 | int fpreg; |
| 637 | |
| 638 | ftag = (buf[1] << 8) | buf[0]; |
| 639 | buf[0] = 0; |
| 640 | buf[1] = 0; |
| 641 | |
| 642 | for (fpreg = 7; fpreg >= 0; fpreg--) |
| 643 | { |
| 644 | int tag = (ftag >> (fpreg * 2)) & 3; |
| 645 | |
| 646 | if (tag != 3) |
| 647 | buf[0] |= (1 << fpreg); |
| 648 | } |
| 649 | } |
| 650 | memcpy (FXSAVE_ADDR (fxsave, i), buf, 2); |
| 651 | } |
| 652 | else |
| 653 | regcache_collect (i, FXSAVE_ADDR (fxsave, i)); |
| 654 | } |
| 655 | } |
| 656 | |
| 657 | /* Recreate the FTW (tag word) valid bits from the 80-bit FP data in |
| 658 | *RAW. */ |
| 659 | |
| 660 | static int |
| 661 | i387_tag (unsigned char *raw) |
| 662 | { |
| 663 | int integer; |
| 664 | unsigned int exponent; |
| 665 | unsigned long fraction[2]; |
| 666 | |
| 667 | integer = raw[7] & 0x80; |
| 668 | exponent = (((raw[9] & 0x7f) << 8) | raw[8]); |
| 669 | fraction[0] = ((raw[3] << 24) | (raw[2] << 16) | (raw[1] << 8) | raw[0]); |
| 670 | fraction[1] = (((raw[7] & 0x7f) << 24) | (raw[6] << 16) |
| 671 | | (raw[5] << 8) | raw[4]); |
| 672 | |
| 673 | if (exponent == 0x7fff) |
| 674 | { |
| 675 | /* Special. */ |
| 676 | return (2); |
| 677 | } |
| 678 | else if (exponent == 0x0000) |
| 679 | { |
| 680 | if (fraction[0] == 0x0000 && fraction[1] == 0x0000 && !integer) |
| 681 | { |
| 682 | /* Zero. */ |
| 683 | return (1); |
| 684 | } |
| 685 | else |
| 686 | { |
| 687 | /* Special. */ |
| 688 | return (2); |
| 689 | } |
| 690 | } |
| 691 | else |
| 692 | { |
| 693 | if (integer) |
| 694 | { |
| 695 | /* Valid. */ |
| 696 | return (0); |
| 697 | } |
| 698 | else |
| 699 | { |
| 700 | /* Special. */ |
| 701 | return (2); |
| 702 | } |
| 703 | } |
| 704 | } |