Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1 | /* |
| 2 | * linux/arch/arm/vfp/vfpdouble.c |
| 3 | * |
| 4 | * This code is derived in part from John R. Housers softfloat library, which |
| 5 | * carries the following notice: |
| 6 | * |
| 7 | * =========================================================================== |
| 8 | * This C source file is part of the SoftFloat IEC/IEEE Floating-point |
| 9 | * Arithmetic Package, Release 2. |
| 10 | * |
| 11 | * Written by John R. Hauser. This work was made possible in part by the |
| 12 | * International Computer Science Institute, located at Suite 600, 1947 Center |
| 13 | * Street, Berkeley, California 94704. Funding was partially provided by the |
| 14 | * National Science Foundation under grant MIP-9311980. The original version |
| 15 | * of this code was written as part of a project to build a fixed-point vector |
| 16 | * processor in collaboration with the University of California at Berkeley, |
| 17 | * overseen by Profs. Nelson Morgan and John Wawrzynek. More information |
| 18 | * is available through the web page `http://HTTP.CS.Berkeley.EDU/~jhauser/ |
| 19 | * arithmetic/softfloat.html'. |
| 20 | * |
| 21 | * THIS SOFTWARE IS DISTRIBUTED AS IS, FOR FREE. Although reasonable effort |
| 22 | * has been made to avoid it, THIS SOFTWARE MAY CONTAIN FAULTS THAT WILL AT |
| 23 | * TIMES RESULT IN INCORRECT BEHAVIOR. USE OF THIS SOFTWARE IS RESTRICTED TO |
| 24 | * PERSONS AND ORGANIZATIONS WHO CAN AND WILL TAKE FULL RESPONSIBILITY FOR ANY |
| 25 | * AND ALL LOSSES, COSTS, OR OTHER PROBLEMS ARISING FROM ITS USE. |
| 26 | * |
| 27 | * Derivative works are acceptable, even for commercial purposes, so long as |
| 28 | * (1) they include prominent notice that the work is derivative, and (2) they |
| 29 | * include prominent notice akin to these three paragraphs for those parts of |
| 30 | * this code that are retained. |
| 31 | * =========================================================================== |
| 32 | */ |
| 33 | #include <linux/kernel.h> |
| 34 | #include <linux/bitops.h> |
Russell King | 438a761 | 2005-06-29 23:01:02 +0100 | [diff] [blame] | 35 | |
| 36 | #include <asm/div64.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 37 | #include <asm/ptrace.h> |
| 38 | #include <asm/vfp.h> |
| 39 | |
| 40 | #include "vfpinstr.h" |
| 41 | #include "vfp.h" |
| 42 | |
| 43 | static struct vfp_double vfp_double_default_qnan = { |
| 44 | .exponent = 2047, |
| 45 | .sign = 0, |
| 46 | .significand = VFP_DOUBLE_SIGNIFICAND_QNAN, |
| 47 | }; |
| 48 | |
| 49 | static void vfp_double_dump(const char *str, struct vfp_double *d) |
| 50 | { |
| 51 | pr_debug("VFP: %s: sign=%d exponent=%d significand=%016llx\n", |
| 52 | str, d->sign != 0, d->exponent, d->significand); |
| 53 | } |
| 54 | |
| 55 | static void vfp_double_normalise_denormal(struct vfp_double *vd) |
| 56 | { |
| 57 | int bits = 31 - fls(vd->significand >> 32); |
| 58 | if (bits == 31) |
| 59 | bits = 62 - fls(vd->significand); |
| 60 | |
| 61 | vfp_double_dump("normalise_denormal: in", vd); |
| 62 | |
| 63 | if (bits) { |
| 64 | vd->exponent -= bits - 1; |
| 65 | vd->significand <<= bits; |
| 66 | } |
| 67 | |
| 68 | vfp_double_dump("normalise_denormal: out", vd); |
| 69 | } |
| 70 | |
| 71 | u32 vfp_double_normaliseround(int dd, struct vfp_double *vd, u32 fpscr, u32 exceptions, const char *func) |
| 72 | { |
| 73 | u64 significand, incr; |
| 74 | int exponent, shift, underflow; |
| 75 | u32 rmode; |
| 76 | |
| 77 | vfp_double_dump("pack: in", vd); |
| 78 | |
| 79 | /* |
| 80 | * Infinities and NaNs are a special case. |
| 81 | */ |
| 82 | if (vd->exponent == 2047 && (vd->significand == 0 || exceptions)) |
| 83 | goto pack; |
| 84 | |
| 85 | /* |
| 86 | * Special-case zero. |
| 87 | */ |
| 88 | if (vd->significand == 0) { |
| 89 | vd->exponent = 0; |
| 90 | goto pack; |
| 91 | } |
| 92 | |
| 93 | exponent = vd->exponent; |
| 94 | significand = vd->significand; |
| 95 | |
| 96 | shift = 32 - fls(significand >> 32); |
| 97 | if (shift == 32) |
| 98 | shift = 64 - fls(significand); |
| 99 | if (shift) { |
| 100 | exponent -= shift; |
| 101 | significand <<= shift; |
| 102 | } |
| 103 | |
| 104 | #ifdef DEBUG |
| 105 | vd->exponent = exponent; |
| 106 | vd->significand = significand; |
| 107 | vfp_double_dump("pack: normalised", vd); |
| 108 | #endif |
| 109 | |
| 110 | /* |
| 111 | * Tiny number? |
| 112 | */ |
| 113 | underflow = exponent < 0; |
| 114 | if (underflow) { |
| 115 | significand = vfp_shiftright64jamming(significand, -exponent); |
| 116 | exponent = 0; |
| 117 | #ifdef DEBUG |
| 118 | vd->exponent = exponent; |
| 119 | vd->significand = significand; |
| 120 | vfp_double_dump("pack: tiny number", vd); |
| 121 | #endif |
| 122 | if (!(significand & ((1ULL << (VFP_DOUBLE_LOW_BITS + 1)) - 1))) |
| 123 | underflow = 0; |
| 124 | } |
| 125 | |
| 126 | /* |
| 127 | * Select rounding increment. |
| 128 | */ |
| 129 | incr = 0; |
| 130 | rmode = fpscr & FPSCR_RMODE_MASK; |
| 131 | |
| 132 | if (rmode == FPSCR_ROUND_NEAREST) { |
| 133 | incr = 1ULL << VFP_DOUBLE_LOW_BITS; |
| 134 | if ((significand & (1ULL << (VFP_DOUBLE_LOW_BITS + 1))) == 0) |
| 135 | incr -= 1; |
| 136 | } else if (rmode == FPSCR_ROUND_TOZERO) { |
| 137 | incr = 0; |
| 138 | } else if ((rmode == FPSCR_ROUND_PLUSINF) ^ (vd->sign != 0)) |
| 139 | incr = (1ULL << (VFP_DOUBLE_LOW_BITS + 1)) - 1; |
| 140 | |
| 141 | pr_debug("VFP: rounding increment = 0x%08llx\n", incr); |
| 142 | |
| 143 | /* |
| 144 | * Is our rounding going to overflow? |
| 145 | */ |
| 146 | if ((significand + incr) < significand) { |
| 147 | exponent += 1; |
| 148 | significand = (significand >> 1) | (significand & 1); |
| 149 | incr >>= 1; |
| 150 | #ifdef DEBUG |
| 151 | vd->exponent = exponent; |
| 152 | vd->significand = significand; |
| 153 | vfp_double_dump("pack: overflow", vd); |
| 154 | #endif |
| 155 | } |
| 156 | |
| 157 | /* |
| 158 | * If any of the low bits (which will be shifted out of the |
| 159 | * number) are non-zero, the result is inexact. |
| 160 | */ |
| 161 | if (significand & ((1 << (VFP_DOUBLE_LOW_BITS + 1)) - 1)) |
| 162 | exceptions |= FPSCR_IXC; |
| 163 | |
| 164 | /* |
| 165 | * Do our rounding. |
| 166 | */ |
| 167 | significand += incr; |
| 168 | |
| 169 | /* |
| 170 | * Infinity? |
| 171 | */ |
| 172 | if (exponent >= 2046) { |
| 173 | exceptions |= FPSCR_OFC | FPSCR_IXC; |
| 174 | if (incr == 0) { |
| 175 | vd->exponent = 2045; |
| 176 | vd->significand = 0x7fffffffffffffffULL; |
| 177 | } else { |
| 178 | vd->exponent = 2047; /* infinity */ |
| 179 | vd->significand = 0; |
| 180 | } |
| 181 | } else { |
| 182 | if (significand >> (VFP_DOUBLE_LOW_BITS + 1) == 0) |
| 183 | exponent = 0; |
| 184 | if (exponent || significand > 0x8000000000000000ULL) |
| 185 | underflow = 0; |
| 186 | if (underflow) |
| 187 | exceptions |= FPSCR_UFC; |
| 188 | vd->exponent = exponent; |
| 189 | vd->significand = significand >> 1; |
| 190 | } |
| 191 | |
| 192 | pack: |
| 193 | vfp_double_dump("pack: final", vd); |
| 194 | { |
| 195 | s64 d = vfp_double_pack(vd); |
| 196 | pr_debug("VFP: %s: d(d%d)=%016llx exceptions=%08x\n", func, |
| 197 | dd, d, exceptions); |
| 198 | vfp_put_double(dd, d); |
| 199 | } |
| 200 | return exceptions & ~VFP_NAN_FLAG; |
| 201 | } |
| 202 | |
| 203 | /* |
| 204 | * Propagate the NaN, setting exceptions if it is signalling. |
| 205 | * 'n' is always a NaN. 'm' may be a number, NaN or infinity. |
| 206 | */ |
| 207 | static u32 |
| 208 | vfp_propagate_nan(struct vfp_double *vdd, struct vfp_double *vdn, |
| 209 | struct vfp_double *vdm, u32 fpscr) |
| 210 | { |
| 211 | struct vfp_double *nan; |
| 212 | int tn, tm = 0; |
| 213 | |
| 214 | tn = vfp_double_type(vdn); |
| 215 | |
| 216 | if (vdm) |
| 217 | tm = vfp_double_type(vdm); |
| 218 | |
| 219 | if (fpscr & FPSCR_DEFAULT_NAN) |
| 220 | /* |
| 221 | * Default NaN mode - always returns a quiet NaN |
| 222 | */ |
| 223 | nan = &vfp_double_default_qnan; |
| 224 | else { |
| 225 | /* |
| 226 | * Contemporary mode - select the first signalling |
| 227 | * NAN, or if neither are signalling, the first |
| 228 | * quiet NAN. |
| 229 | */ |
| 230 | if (tn == VFP_SNAN || (tm != VFP_SNAN && tn == VFP_QNAN)) |
| 231 | nan = vdn; |
| 232 | else |
| 233 | nan = vdm; |
| 234 | /* |
| 235 | * Make the NaN quiet. |
| 236 | */ |
| 237 | nan->significand |= VFP_DOUBLE_SIGNIFICAND_QNAN; |
| 238 | } |
| 239 | |
| 240 | *vdd = *nan; |
| 241 | |
| 242 | /* |
| 243 | * If one was a signalling NAN, raise invalid operation. |
| 244 | */ |
| 245 | return tn == VFP_SNAN || tm == VFP_SNAN ? FPSCR_IOC : VFP_NAN_FLAG; |
| 246 | } |
| 247 | |
| 248 | /* |
| 249 | * Extended operations |
| 250 | */ |
| 251 | static u32 vfp_double_fabs(int dd, int unused, int dm, u32 fpscr) |
| 252 | { |
| 253 | vfp_put_double(dd, vfp_double_packed_abs(vfp_get_double(dm))); |
| 254 | return 0; |
| 255 | } |
| 256 | |
| 257 | static u32 vfp_double_fcpy(int dd, int unused, int dm, u32 fpscr) |
| 258 | { |
| 259 | vfp_put_double(dd, vfp_get_double(dm)); |
| 260 | return 0; |
| 261 | } |
| 262 | |
| 263 | static u32 vfp_double_fneg(int dd, int unused, int dm, u32 fpscr) |
| 264 | { |
| 265 | vfp_put_double(dd, vfp_double_packed_negate(vfp_get_double(dm))); |
| 266 | return 0; |
| 267 | } |
| 268 | |
| 269 | static u32 vfp_double_fsqrt(int dd, int unused, int dm, u32 fpscr) |
| 270 | { |
| 271 | struct vfp_double vdm, vdd; |
| 272 | int ret, tm; |
| 273 | |
| 274 | vfp_double_unpack(&vdm, vfp_get_double(dm)); |
| 275 | tm = vfp_double_type(&vdm); |
| 276 | if (tm & (VFP_NAN|VFP_INFINITY)) { |
| 277 | struct vfp_double *vdp = &vdd; |
| 278 | |
| 279 | if (tm & VFP_NAN) |
| 280 | ret = vfp_propagate_nan(vdp, &vdm, NULL, fpscr); |
| 281 | else if (vdm.sign == 0) { |
| 282 | sqrt_copy: |
| 283 | vdp = &vdm; |
| 284 | ret = 0; |
| 285 | } else { |
| 286 | sqrt_invalid: |
| 287 | vdp = &vfp_double_default_qnan; |
| 288 | ret = FPSCR_IOC; |
| 289 | } |
| 290 | vfp_put_double(dd, vfp_double_pack(vdp)); |
| 291 | return ret; |
| 292 | } |
| 293 | |
| 294 | /* |
| 295 | * sqrt(+/- 0) == +/- 0 |
| 296 | */ |
| 297 | if (tm & VFP_ZERO) |
| 298 | goto sqrt_copy; |
| 299 | |
| 300 | /* |
| 301 | * Normalise a denormalised number |
| 302 | */ |
| 303 | if (tm & VFP_DENORMAL) |
| 304 | vfp_double_normalise_denormal(&vdm); |
| 305 | |
| 306 | /* |
| 307 | * sqrt(<0) = invalid |
| 308 | */ |
| 309 | if (vdm.sign) |
| 310 | goto sqrt_invalid; |
| 311 | |
| 312 | vfp_double_dump("sqrt", &vdm); |
| 313 | |
| 314 | /* |
| 315 | * Estimate the square root. |
| 316 | */ |
| 317 | vdd.sign = 0; |
| 318 | vdd.exponent = ((vdm.exponent - 1023) >> 1) + 1023; |
| 319 | vdd.significand = (u64)vfp_estimate_sqrt_significand(vdm.exponent, vdm.significand >> 32) << 31; |
| 320 | |
| 321 | vfp_double_dump("sqrt estimate1", &vdd); |
| 322 | |
| 323 | vdm.significand >>= 1 + (vdm.exponent & 1); |
| 324 | vdd.significand += 2 + vfp_estimate_div128to64(vdm.significand, 0, vdd.significand); |
| 325 | |
| 326 | vfp_double_dump("sqrt estimate2", &vdd); |
| 327 | |
| 328 | /* |
| 329 | * And now adjust. |
| 330 | */ |
| 331 | if ((vdd.significand & VFP_DOUBLE_LOW_BITS_MASK) <= 5) { |
| 332 | if (vdd.significand < 2) { |
| 333 | vdd.significand = ~0ULL; |
| 334 | } else { |
| 335 | u64 termh, terml, remh, reml; |
| 336 | vdm.significand <<= 2; |
| 337 | mul64to128(&termh, &terml, vdd.significand, vdd.significand); |
| 338 | sub128(&remh, &reml, vdm.significand, 0, termh, terml); |
| 339 | while ((s64)remh < 0) { |
| 340 | vdd.significand -= 1; |
| 341 | shift64left(&termh, &terml, vdd.significand); |
| 342 | terml |= 1; |
| 343 | add128(&remh, &reml, remh, reml, termh, terml); |
| 344 | } |
| 345 | vdd.significand |= (remh | reml) != 0; |
| 346 | } |
| 347 | } |
| 348 | vdd.significand = vfp_shiftright64jamming(vdd.significand, 1); |
| 349 | |
| 350 | return vfp_double_normaliseround(dd, &vdd, fpscr, 0, "fsqrt"); |
| 351 | } |
| 352 | |
| 353 | /* |
| 354 | * Equal := ZC |
| 355 | * Less than := N |
| 356 | * Greater than := C |
| 357 | * Unordered := CV |
| 358 | */ |
| 359 | static u32 vfp_compare(int dd, int signal_on_qnan, int dm, u32 fpscr) |
| 360 | { |
| 361 | s64 d, m; |
| 362 | u32 ret = 0; |
| 363 | |
| 364 | m = vfp_get_double(dm); |
| 365 | if (vfp_double_packed_exponent(m) == 2047 && vfp_double_packed_mantissa(m)) { |
| 366 | ret |= FPSCR_C | FPSCR_V; |
| 367 | if (signal_on_qnan || !(vfp_double_packed_mantissa(m) & (1ULL << (VFP_DOUBLE_MANTISSA_BITS - 1)))) |
| 368 | /* |
| 369 | * Signalling NaN, or signalling on quiet NaN |
| 370 | */ |
| 371 | ret |= FPSCR_IOC; |
| 372 | } |
| 373 | |
| 374 | d = vfp_get_double(dd); |
| 375 | if (vfp_double_packed_exponent(d) == 2047 && vfp_double_packed_mantissa(d)) { |
| 376 | ret |= FPSCR_C | FPSCR_V; |
| 377 | if (signal_on_qnan || !(vfp_double_packed_mantissa(d) & (1ULL << (VFP_DOUBLE_MANTISSA_BITS - 1)))) |
| 378 | /* |
| 379 | * Signalling NaN, or signalling on quiet NaN |
| 380 | */ |
| 381 | ret |= FPSCR_IOC; |
| 382 | } |
| 383 | |
| 384 | if (ret == 0) { |
| 385 | if (d == m || vfp_double_packed_abs(d | m) == 0) { |
| 386 | /* |
| 387 | * equal |
| 388 | */ |
| 389 | ret |= FPSCR_Z | FPSCR_C; |
| 390 | } else if (vfp_double_packed_sign(d ^ m)) { |
| 391 | /* |
| 392 | * different signs |
| 393 | */ |
| 394 | if (vfp_double_packed_sign(d)) |
| 395 | /* |
| 396 | * d is negative, so d < m |
| 397 | */ |
| 398 | ret |= FPSCR_N; |
| 399 | else |
| 400 | /* |
| 401 | * d is positive, so d > m |
| 402 | */ |
| 403 | ret |= FPSCR_C; |
| 404 | } else if ((vfp_double_packed_sign(d) != 0) ^ (d < m)) { |
| 405 | /* |
| 406 | * d < m |
| 407 | */ |
| 408 | ret |= FPSCR_N; |
| 409 | } else if ((vfp_double_packed_sign(d) != 0) ^ (d > m)) { |
| 410 | /* |
| 411 | * d > m |
| 412 | */ |
| 413 | ret |= FPSCR_C; |
| 414 | } |
| 415 | } |
| 416 | |
| 417 | return ret; |
| 418 | } |
| 419 | |
| 420 | static u32 vfp_double_fcmp(int dd, int unused, int dm, u32 fpscr) |
| 421 | { |
| 422 | return vfp_compare(dd, 0, dm, fpscr); |
| 423 | } |
| 424 | |
| 425 | static u32 vfp_double_fcmpe(int dd, int unused, int dm, u32 fpscr) |
| 426 | { |
| 427 | return vfp_compare(dd, 1, dm, fpscr); |
| 428 | } |
| 429 | |
| 430 | static u32 vfp_double_fcmpz(int dd, int unused, int dm, u32 fpscr) |
| 431 | { |
| 432 | return vfp_compare(dd, 0, VFP_REG_ZERO, fpscr); |
| 433 | } |
| 434 | |
| 435 | static u32 vfp_double_fcmpez(int dd, int unused, int dm, u32 fpscr) |
| 436 | { |
| 437 | return vfp_compare(dd, 1, VFP_REG_ZERO, fpscr); |
| 438 | } |
| 439 | |
| 440 | static u32 vfp_double_fcvts(int sd, int unused, int dm, u32 fpscr) |
| 441 | { |
| 442 | struct vfp_double vdm; |
| 443 | struct vfp_single vsd; |
| 444 | int tm; |
| 445 | u32 exceptions = 0; |
| 446 | |
| 447 | vfp_double_unpack(&vdm, vfp_get_double(dm)); |
| 448 | |
| 449 | tm = vfp_double_type(&vdm); |
| 450 | |
| 451 | /* |
| 452 | * If we have a signalling NaN, signal invalid operation. |
| 453 | */ |
| 454 | if (tm == VFP_SNAN) |
| 455 | exceptions = FPSCR_IOC; |
| 456 | |
| 457 | if (tm & VFP_DENORMAL) |
| 458 | vfp_double_normalise_denormal(&vdm); |
| 459 | |
| 460 | vsd.sign = vdm.sign; |
| 461 | vsd.significand = vfp_hi64to32jamming(vdm.significand); |
| 462 | |
| 463 | /* |
| 464 | * If we have an infinity or a NaN, the exponent must be 255 |
| 465 | */ |
| 466 | if (tm & (VFP_INFINITY|VFP_NAN)) { |
| 467 | vsd.exponent = 255; |
| 468 | if (tm & VFP_NAN) |
| 469 | vsd.significand |= VFP_SINGLE_SIGNIFICAND_QNAN; |
| 470 | goto pack_nan; |
| 471 | } else if (tm & VFP_ZERO) |
| 472 | vsd.exponent = 0; |
| 473 | else |
| 474 | vsd.exponent = vdm.exponent - (1023 - 127); |
| 475 | |
| 476 | return vfp_single_normaliseround(sd, &vsd, fpscr, exceptions, "fcvts"); |
| 477 | |
| 478 | pack_nan: |
| 479 | vfp_put_float(sd, vfp_single_pack(&vsd)); |
| 480 | return exceptions; |
| 481 | } |
| 482 | |
| 483 | static u32 vfp_double_fuito(int dd, int unused, int dm, u32 fpscr) |
| 484 | { |
| 485 | struct vfp_double vdm; |
| 486 | u32 m = vfp_get_float(dm); |
| 487 | |
| 488 | vdm.sign = 0; |
| 489 | vdm.exponent = 1023 + 63 - 1; |
| 490 | vdm.significand = (u64)m; |
| 491 | |
| 492 | return vfp_double_normaliseround(dd, &vdm, fpscr, 0, "fuito"); |
| 493 | } |
| 494 | |
| 495 | static u32 vfp_double_fsito(int dd, int unused, int dm, u32 fpscr) |
| 496 | { |
| 497 | struct vfp_double vdm; |
| 498 | u32 m = vfp_get_float(dm); |
| 499 | |
| 500 | vdm.sign = (m & 0x80000000) >> 16; |
| 501 | vdm.exponent = 1023 + 63 - 1; |
| 502 | vdm.significand = vdm.sign ? -m : m; |
| 503 | |
| 504 | return vfp_double_normaliseround(dd, &vdm, fpscr, 0, "fsito"); |
| 505 | } |
| 506 | |
| 507 | static u32 vfp_double_ftoui(int sd, int unused, int dm, u32 fpscr) |
| 508 | { |
| 509 | struct vfp_double vdm; |
| 510 | u32 d, exceptions = 0; |
| 511 | int rmode = fpscr & FPSCR_RMODE_MASK; |
| 512 | int tm; |
| 513 | |
| 514 | vfp_double_unpack(&vdm, vfp_get_double(dm)); |
| 515 | |
| 516 | /* |
| 517 | * Do we have a denormalised number? |
| 518 | */ |
| 519 | tm = vfp_double_type(&vdm); |
| 520 | if (tm & VFP_DENORMAL) |
| 521 | exceptions |= FPSCR_IDC; |
| 522 | |
| 523 | if (tm & VFP_NAN) |
| 524 | vdm.sign = 0; |
| 525 | |
| 526 | if (vdm.exponent >= 1023 + 32) { |
| 527 | d = vdm.sign ? 0 : 0xffffffff; |
| 528 | exceptions = FPSCR_IOC; |
| 529 | } else if (vdm.exponent >= 1023 - 1) { |
| 530 | int shift = 1023 + 63 - vdm.exponent; |
| 531 | u64 rem, incr = 0; |
| 532 | |
| 533 | /* |
| 534 | * 2^0 <= m < 2^32-2^8 |
| 535 | */ |
| 536 | d = (vdm.significand << 1) >> shift; |
| 537 | rem = vdm.significand << (65 - shift); |
| 538 | |
| 539 | if (rmode == FPSCR_ROUND_NEAREST) { |
| 540 | incr = 0x8000000000000000ULL; |
| 541 | if ((d & 1) == 0) |
| 542 | incr -= 1; |
| 543 | } else if (rmode == FPSCR_ROUND_TOZERO) { |
| 544 | incr = 0; |
| 545 | } else if ((rmode == FPSCR_ROUND_PLUSINF) ^ (vdm.sign != 0)) { |
| 546 | incr = ~0ULL; |
| 547 | } |
| 548 | |
| 549 | if ((rem + incr) < rem) { |
| 550 | if (d < 0xffffffff) |
| 551 | d += 1; |
| 552 | else |
| 553 | exceptions |= FPSCR_IOC; |
| 554 | } |
| 555 | |
| 556 | if (d && vdm.sign) { |
| 557 | d = 0; |
| 558 | exceptions |= FPSCR_IOC; |
| 559 | } else if (rem) |
| 560 | exceptions |= FPSCR_IXC; |
| 561 | } else { |
| 562 | d = 0; |
| 563 | if (vdm.exponent | vdm.significand) { |
| 564 | exceptions |= FPSCR_IXC; |
| 565 | if (rmode == FPSCR_ROUND_PLUSINF && vdm.sign == 0) |
| 566 | d = 1; |
| 567 | else if (rmode == FPSCR_ROUND_MINUSINF && vdm.sign) { |
| 568 | d = 0; |
| 569 | exceptions |= FPSCR_IOC; |
| 570 | } |
| 571 | } |
| 572 | } |
| 573 | |
| 574 | pr_debug("VFP: ftoui: d(s%d)=%08x exceptions=%08x\n", sd, d, exceptions); |
| 575 | |
| 576 | vfp_put_float(sd, d); |
| 577 | |
| 578 | return exceptions; |
| 579 | } |
| 580 | |
| 581 | static u32 vfp_double_ftouiz(int sd, int unused, int dm, u32 fpscr) |
| 582 | { |
| 583 | return vfp_double_ftoui(sd, unused, dm, FPSCR_ROUND_TOZERO); |
| 584 | } |
| 585 | |
| 586 | static u32 vfp_double_ftosi(int sd, int unused, int dm, u32 fpscr) |
| 587 | { |
| 588 | struct vfp_double vdm; |
| 589 | u32 d, exceptions = 0; |
| 590 | int rmode = fpscr & FPSCR_RMODE_MASK; |
| 591 | |
| 592 | vfp_double_unpack(&vdm, vfp_get_double(dm)); |
| 593 | vfp_double_dump("VDM", &vdm); |
| 594 | |
| 595 | /* |
| 596 | * Do we have denormalised number? |
| 597 | */ |
| 598 | if (vfp_double_type(&vdm) & VFP_DENORMAL) |
| 599 | exceptions |= FPSCR_IDC; |
| 600 | |
| 601 | if (vdm.exponent >= 1023 + 32) { |
| 602 | d = 0x7fffffff; |
| 603 | if (vdm.sign) |
| 604 | d = ~d; |
| 605 | exceptions |= FPSCR_IOC; |
| 606 | } else if (vdm.exponent >= 1023 - 1) { |
| 607 | int shift = 1023 + 63 - vdm.exponent; /* 58 */ |
| 608 | u64 rem, incr = 0; |
| 609 | |
| 610 | d = (vdm.significand << 1) >> shift; |
| 611 | rem = vdm.significand << (65 - shift); |
| 612 | |
| 613 | if (rmode == FPSCR_ROUND_NEAREST) { |
| 614 | incr = 0x8000000000000000ULL; |
| 615 | if ((d & 1) == 0) |
| 616 | incr -= 1; |
| 617 | } else if (rmode == FPSCR_ROUND_TOZERO) { |
| 618 | incr = 0; |
| 619 | } else if ((rmode == FPSCR_ROUND_PLUSINF) ^ (vdm.sign != 0)) { |
| 620 | incr = ~0ULL; |
| 621 | } |
| 622 | |
| 623 | if ((rem + incr) < rem && d < 0xffffffff) |
| 624 | d += 1; |
| 625 | if (d > 0x7fffffff + (vdm.sign != 0)) { |
| 626 | d = 0x7fffffff + (vdm.sign != 0); |
| 627 | exceptions |= FPSCR_IOC; |
| 628 | } else if (rem) |
| 629 | exceptions |= FPSCR_IXC; |
| 630 | |
| 631 | if (vdm.sign) |
| 632 | d = -d; |
| 633 | } else { |
| 634 | d = 0; |
| 635 | if (vdm.exponent | vdm.significand) { |
| 636 | exceptions |= FPSCR_IXC; |
| 637 | if (rmode == FPSCR_ROUND_PLUSINF && vdm.sign == 0) |
| 638 | d = 1; |
| 639 | else if (rmode == FPSCR_ROUND_MINUSINF && vdm.sign) |
| 640 | d = -1; |
| 641 | } |
| 642 | } |
| 643 | |
| 644 | pr_debug("VFP: ftosi: d(s%d)=%08x exceptions=%08x\n", sd, d, exceptions); |
| 645 | |
| 646 | vfp_put_float(sd, (s32)d); |
| 647 | |
| 648 | return exceptions; |
| 649 | } |
| 650 | |
| 651 | static u32 vfp_double_ftosiz(int dd, int unused, int dm, u32 fpscr) |
| 652 | { |
| 653 | return vfp_double_ftosi(dd, unused, dm, FPSCR_ROUND_TOZERO); |
| 654 | } |
| 655 | |
| 656 | |
| 657 | static u32 (* const fop_extfns[32])(int dd, int unused, int dm, u32 fpscr) = { |
| 658 | [FEXT_TO_IDX(FEXT_FCPY)] = vfp_double_fcpy, |
| 659 | [FEXT_TO_IDX(FEXT_FABS)] = vfp_double_fabs, |
| 660 | [FEXT_TO_IDX(FEXT_FNEG)] = vfp_double_fneg, |
| 661 | [FEXT_TO_IDX(FEXT_FSQRT)] = vfp_double_fsqrt, |
| 662 | [FEXT_TO_IDX(FEXT_FCMP)] = vfp_double_fcmp, |
| 663 | [FEXT_TO_IDX(FEXT_FCMPE)] = vfp_double_fcmpe, |
| 664 | [FEXT_TO_IDX(FEXT_FCMPZ)] = vfp_double_fcmpz, |
| 665 | [FEXT_TO_IDX(FEXT_FCMPEZ)] = vfp_double_fcmpez, |
| 666 | [FEXT_TO_IDX(FEXT_FCVT)] = vfp_double_fcvts, |
| 667 | [FEXT_TO_IDX(FEXT_FUITO)] = vfp_double_fuito, |
| 668 | [FEXT_TO_IDX(FEXT_FSITO)] = vfp_double_fsito, |
| 669 | [FEXT_TO_IDX(FEXT_FTOUI)] = vfp_double_ftoui, |
| 670 | [FEXT_TO_IDX(FEXT_FTOUIZ)] = vfp_double_ftouiz, |
| 671 | [FEXT_TO_IDX(FEXT_FTOSI)] = vfp_double_ftosi, |
| 672 | [FEXT_TO_IDX(FEXT_FTOSIZ)] = vfp_double_ftosiz, |
| 673 | }; |
| 674 | |
| 675 | |
| 676 | |
| 677 | |
| 678 | static u32 |
| 679 | vfp_double_fadd_nonnumber(struct vfp_double *vdd, struct vfp_double *vdn, |
| 680 | struct vfp_double *vdm, u32 fpscr) |
| 681 | { |
| 682 | struct vfp_double *vdp; |
| 683 | u32 exceptions = 0; |
| 684 | int tn, tm; |
| 685 | |
| 686 | tn = vfp_double_type(vdn); |
| 687 | tm = vfp_double_type(vdm); |
| 688 | |
| 689 | if (tn & tm & VFP_INFINITY) { |
| 690 | /* |
| 691 | * Two infinities. Are they different signs? |
| 692 | */ |
| 693 | if (vdn->sign ^ vdm->sign) { |
| 694 | /* |
| 695 | * different signs -> invalid |
| 696 | */ |
| 697 | exceptions = FPSCR_IOC; |
| 698 | vdp = &vfp_double_default_qnan; |
| 699 | } else { |
| 700 | /* |
| 701 | * same signs -> valid |
| 702 | */ |
| 703 | vdp = vdn; |
| 704 | } |
| 705 | } else if (tn & VFP_INFINITY && tm & VFP_NUMBER) { |
| 706 | /* |
| 707 | * One infinity and one number -> infinity |
| 708 | */ |
| 709 | vdp = vdn; |
| 710 | } else { |
| 711 | /* |
| 712 | * 'n' is a NaN of some type |
| 713 | */ |
| 714 | return vfp_propagate_nan(vdd, vdn, vdm, fpscr); |
| 715 | } |
| 716 | *vdd = *vdp; |
| 717 | return exceptions; |
| 718 | } |
| 719 | |
| 720 | static u32 |
| 721 | vfp_double_add(struct vfp_double *vdd, struct vfp_double *vdn, |
| 722 | struct vfp_double *vdm, u32 fpscr) |
| 723 | { |
| 724 | u32 exp_diff; |
| 725 | u64 m_sig; |
| 726 | |
| 727 | if (vdn->significand & (1ULL << 63) || |
| 728 | vdm->significand & (1ULL << 63)) { |
| 729 | pr_info("VFP: bad FP values in %s\n", __func__); |
| 730 | vfp_double_dump("VDN", vdn); |
| 731 | vfp_double_dump("VDM", vdm); |
| 732 | } |
| 733 | |
| 734 | /* |
| 735 | * Ensure that 'n' is the largest magnitude number. Note that |
| 736 | * if 'n' and 'm' have equal exponents, we do not swap them. |
| 737 | * This ensures that NaN propagation works correctly. |
| 738 | */ |
| 739 | if (vdn->exponent < vdm->exponent) { |
| 740 | struct vfp_double *t = vdn; |
| 741 | vdn = vdm; |
| 742 | vdm = t; |
| 743 | } |
| 744 | |
| 745 | /* |
| 746 | * Is 'n' an infinity or a NaN? Note that 'm' may be a number, |
| 747 | * infinity or a NaN here. |
| 748 | */ |
| 749 | if (vdn->exponent == 2047) |
| 750 | return vfp_double_fadd_nonnumber(vdd, vdn, vdm, fpscr); |
| 751 | |
| 752 | /* |
| 753 | * We have two proper numbers, where 'vdn' is the larger magnitude. |
| 754 | * |
| 755 | * Copy 'n' to 'd' before doing the arithmetic. |
| 756 | */ |
| 757 | *vdd = *vdn; |
| 758 | |
| 759 | /* |
| 760 | * Align 'm' with the result. |
| 761 | */ |
| 762 | exp_diff = vdn->exponent - vdm->exponent; |
| 763 | m_sig = vfp_shiftright64jamming(vdm->significand, exp_diff); |
| 764 | |
| 765 | /* |
| 766 | * If the signs are different, we are really subtracting. |
| 767 | */ |
| 768 | if (vdn->sign ^ vdm->sign) { |
| 769 | m_sig = vdn->significand - m_sig; |
| 770 | if ((s64)m_sig < 0) { |
| 771 | vdd->sign = vfp_sign_negate(vdd->sign); |
| 772 | m_sig = -m_sig; |
Catalin Marinas | 7b1fbf2 | 2005-08-03 19:53:25 +0100 | [diff] [blame] | 773 | } else if (m_sig == 0) { |
| 774 | vdd->sign = (fpscr & FPSCR_RMODE_MASK) == |
| 775 | FPSCR_ROUND_MINUSINF ? 0x8000 : 0; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 776 | } |
| 777 | } else { |
| 778 | m_sig += vdn->significand; |
| 779 | } |
| 780 | vdd->significand = m_sig; |
| 781 | |
| 782 | return 0; |
| 783 | } |
| 784 | |
| 785 | static u32 |
| 786 | vfp_double_multiply(struct vfp_double *vdd, struct vfp_double *vdn, |
| 787 | struct vfp_double *vdm, u32 fpscr) |
| 788 | { |
| 789 | vfp_double_dump("VDN", vdn); |
| 790 | vfp_double_dump("VDM", vdm); |
| 791 | |
| 792 | /* |
| 793 | * Ensure that 'n' is the largest magnitude number. Note that |
| 794 | * if 'n' and 'm' have equal exponents, we do not swap them. |
| 795 | * This ensures that NaN propagation works correctly. |
| 796 | */ |
| 797 | if (vdn->exponent < vdm->exponent) { |
| 798 | struct vfp_double *t = vdn; |
| 799 | vdn = vdm; |
| 800 | vdm = t; |
| 801 | pr_debug("VFP: swapping M <-> N\n"); |
| 802 | } |
| 803 | |
| 804 | vdd->sign = vdn->sign ^ vdm->sign; |
| 805 | |
| 806 | /* |
| 807 | * If 'n' is an infinity or NaN, handle it. 'm' may be anything. |
| 808 | */ |
| 809 | if (vdn->exponent == 2047) { |
| 810 | if (vdn->significand || (vdm->exponent == 2047 && vdm->significand)) |
| 811 | return vfp_propagate_nan(vdd, vdn, vdm, fpscr); |
| 812 | if ((vdm->exponent | vdm->significand) == 0) { |
| 813 | *vdd = vfp_double_default_qnan; |
| 814 | return FPSCR_IOC; |
| 815 | } |
| 816 | vdd->exponent = vdn->exponent; |
| 817 | vdd->significand = 0; |
| 818 | return 0; |
| 819 | } |
| 820 | |
| 821 | /* |
| 822 | * If 'm' is zero, the result is always zero. In this case, |
| 823 | * 'n' may be zero or a number, but it doesn't matter which. |
| 824 | */ |
| 825 | if ((vdm->exponent | vdm->significand) == 0) { |
| 826 | vdd->exponent = 0; |
| 827 | vdd->significand = 0; |
| 828 | return 0; |
| 829 | } |
| 830 | |
| 831 | /* |
| 832 | * We add 2 to the destination exponent for the same reason |
| 833 | * as the addition case - though this time we have +1 from |
| 834 | * each input operand. |
| 835 | */ |
| 836 | vdd->exponent = vdn->exponent + vdm->exponent - 1023 + 2; |
| 837 | vdd->significand = vfp_hi64multiply64(vdn->significand, vdm->significand); |
| 838 | |
| 839 | vfp_double_dump("VDD", vdd); |
| 840 | return 0; |
| 841 | } |
| 842 | |
| 843 | #define NEG_MULTIPLY (1 << 0) |
| 844 | #define NEG_SUBTRACT (1 << 1) |
| 845 | |
| 846 | static u32 |
| 847 | vfp_double_multiply_accumulate(int dd, int dn, int dm, u32 fpscr, u32 negate, char *func) |
| 848 | { |
| 849 | struct vfp_double vdd, vdp, vdn, vdm; |
| 850 | u32 exceptions; |
| 851 | |
| 852 | vfp_double_unpack(&vdn, vfp_get_double(dn)); |
| 853 | if (vdn.exponent == 0 && vdn.significand) |
| 854 | vfp_double_normalise_denormal(&vdn); |
| 855 | |
| 856 | vfp_double_unpack(&vdm, vfp_get_double(dm)); |
| 857 | if (vdm.exponent == 0 && vdm.significand) |
| 858 | vfp_double_normalise_denormal(&vdm); |
| 859 | |
| 860 | exceptions = vfp_double_multiply(&vdp, &vdn, &vdm, fpscr); |
| 861 | if (negate & NEG_MULTIPLY) |
| 862 | vdp.sign = vfp_sign_negate(vdp.sign); |
| 863 | |
| 864 | vfp_double_unpack(&vdn, vfp_get_double(dd)); |
| 865 | if (negate & NEG_SUBTRACT) |
| 866 | vdn.sign = vfp_sign_negate(vdn.sign); |
| 867 | |
| 868 | exceptions |= vfp_double_add(&vdd, &vdn, &vdp, fpscr); |
| 869 | |
| 870 | return vfp_double_normaliseround(dd, &vdd, fpscr, exceptions, func); |
| 871 | } |
| 872 | |
| 873 | /* |
| 874 | * Standard operations |
| 875 | */ |
| 876 | |
| 877 | /* |
| 878 | * sd = sd + (sn * sm) |
| 879 | */ |
| 880 | static u32 vfp_double_fmac(int dd, int dn, int dm, u32 fpscr) |
| 881 | { |
| 882 | return vfp_double_multiply_accumulate(dd, dn, dm, fpscr, 0, "fmac"); |
| 883 | } |
| 884 | |
| 885 | /* |
| 886 | * sd = sd - (sn * sm) |
| 887 | */ |
| 888 | static u32 vfp_double_fnmac(int dd, int dn, int dm, u32 fpscr) |
| 889 | { |
| 890 | return vfp_double_multiply_accumulate(dd, dn, dm, fpscr, NEG_MULTIPLY, "fnmac"); |
| 891 | } |
| 892 | |
| 893 | /* |
| 894 | * sd = -sd + (sn * sm) |
| 895 | */ |
| 896 | static u32 vfp_double_fmsc(int dd, int dn, int dm, u32 fpscr) |
| 897 | { |
| 898 | return vfp_double_multiply_accumulate(dd, dn, dm, fpscr, NEG_SUBTRACT, "fmsc"); |
| 899 | } |
| 900 | |
| 901 | /* |
| 902 | * sd = -sd - (sn * sm) |
| 903 | */ |
| 904 | static u32 vfp_double_fnmsc(int dd, int dn, int dm, u32 fpscr) |
| 905 | { |
| 906 | return vfp_double_multiply_accumulate(dd, dn, dm, fpscr, NEG_SUBTRACT | NEG_MULTIPLY, "fnmsc"); |
| 907 | } |
| 908 | |
| 909 | /* |
| 910 | * sd = sn * sm |
| 911 | */ |
| 912 | static u32 vfp_double_fmul(int dd, int dn, int dm, u32 fpscr) |
| 913 | { |
| 914 | struct vfp_double vdd, vdn, vdm; |
| 915 | u32 exceptions; |
| 916 | |
| 917 | vfp_double_unpack(&vdn, vfp_get_double(dn)); |
| 918 | if (vdn.exponent == 0 && vdn.significand) |
| 919 | vfp_double_normalise_denormal(&vdn); |
| 920 | |
| 921 | vfp_double_unpack(&vdm, vfp_get_double(dm)); |
| 922 | if (vdm.exponent == 0 && vdm.significand) |
| 923 | vfp_double_normalise_denormal(&vdm); |
| 924 | |
| 925 | exceptions = vfp_double_multiply(&vdd, &vdn, &vdm, fpscr); |
| 926 | return vfp_double_normaliseround(dd, &vdd, fpscr, exceptions, "fmul"); |
| 927 | } |
| 928 | |
| 929 | /* |
| 930 | * sd = -(sn * sm) |
| 931 | */ |
| 932 | static u32 vfp_double_fnmul(int dd, int dn, int dm, u32 fpscr) |
| 933 | { |
| 934 | struct vfp_double vdd, vdn, vdm; |
| 935 | u32 exceptions; |
| 936 | |
| 937 | vfp_double_unpack(&vdn, vfp_get_double(dn)); |
| 938 | if (vdn.exponent == 0 && vdn.significand) |
| 939 | vfp_double_normalise_denormal(&vdn); |
| 940 | |
| 941 | vfp_double_unpack(&vdm, vfp_get_double(dm)); |
| 942 | if (vdm.exponent == 0 && vdm.significand) |
| 943 | vfp_double_normalise_denormal(&vdm); |
| 944 | |
| 945 | exceptions = vfp_double_multiply(&vdd, &vdn, &vdm, fpscr); |
| 946 | vdd.sign = vfp_sign_negate(vdd.sign); |
| 947 | |
| 948 | return vfp_double_normaliseround(dd, &vdd, fpscr, exceptions, "fnmul"); |
| 949 | } |
| 950 | |
| 951 | /* |
| 952 | * sd = sn + sm |
| 953 | */ |
| 954 | static u32 vfp_double_fadd(int dd, int dn, int dm, u32 fpscr) |
| 955 | { |
| 956 | struct vfp_double vdd, vdn, vdm; |
| 957 | u32 exceptions; |
| 958 | |
| 959 | vfp_double_unpack(&vdn, vfp_get_double(dn)); |
| 960 | if (vdn.exponent == 0 && vdn.significand) |
| 961 | vfp_double_normalise_denormal(&vdn); |
| 962 | |
| 963 | vfp_double_unpack(&vdm, vfp_get_double(dm)); |
| 964 | if (vdm.exponent == 0 && vdm.significand) |
| 965 | vfp_double_normalise_denormal(&vdm); |
| 966 | |
| 967 | exceptions = vfp_double_add(&vdd, &vdn, &vdm, fpscr); |
| 968 | |
| 969 | return vfp_double_normaliseround(dd, &vdd, fpscr, exceptions, "fadd"); |
| 970 | } |
| 971 | |
| 972 | /* |
| 973 | * sd = sn - sm |
| 974 | */ |
| 975 | static u32 vfp_double_fsub(int dd, int dn, int dm, u32 fpscr) |
| 976 | { |
| 977 | struct vfp_double vdd, vdn, vdm; |
| 978 | u32 exceptions; |
| 979 | |
| 980 | vfp_double_unpack(&vdn, vfp_get_double(dn)); |
| 981 | if (vdn.exponent == 0 && vdn.significand) |
| 982 | vfp_double_normalise_denormal(&vdn); |
| 983 | |
| 984 | vfp_double_unpack(&vdm, vfp_get_double(dm)); |
| 985 | if (vdm.exponent == 0 && vdm.significand) |
| 986 | vfp_double_normalise_denormal(&vdm); |
| 987 | |
| 988 | /* |
| 989 | * Subtraction is like addition, but with a negated operand. |
| 990 | */ |
| 991 | vdm.sign = vfp_sign_negate(vdm.sign); |
| 992 | |
| 993 | exceptions = vfp_double_add(&vdd, &vdn, &vdm, fpscr); |
| 994 | |
| 995 | return vfp_double_normaliseround(dd, &vdd, fpscr, exceptions, "fsub"); |
| 996 | } |
| 997 | |
| 998 | /* |
| 999 | * sd = sn / sm |
| 1000 | */ |
| 1001 | static u32 vfp_double_fdiv(int dd, int dn, int dm, u32 fpscr) |
| 1002 | { |
| 1003 | struct vfp_double vdd, vdn, vdm; |
| 1004 | u32 exceptions = 0; |
| 1005 | int tm, tn; |
| 1006 | |
| 1007 | vfp_double_unpack(&vdn, vfp_get_double(dn)); |
| 1008 | vfp_double_unpack(&vdm, vfp_get_double(dm)); |
| 1009 | |
| 1010 | vdd.sign = vdn.sign ^ vdm.sign; |
| 1011 | |
| 1012 | tn = vfp_double_type(&vdn); |
| 1013 | tm = vfp_double_type(&vdm); |
| 1014 | |
| 1015 | /* |
| 1016 | * Is n a NAN? |
| 1017 | */ |
| 1018 | if (tn & VFP_NAN) |
| 1019 | goto vdn_nan; |
| 1020 | |
| 1021 | /* |
| 1022 | * Is m a NAN? |
| 1023 | */ |
| 1024 | if (tm & VFP_NAN) |
| 1025 | goto vdm_nan; |
| 1026 | |
| 1027 | /* |
| 1028 | * If n and m are infinity, the result is invalid |
| 1029 | * If n and m are zero, the result is invalid |
| 1030 | */ |
| 1031 | if (tm & tn & (VFP_INFINITY|VFP_ZERO)) |
| 1032 | goto invalid; |
| 1033 | |
| 1034 | /* |
| 1035 | * If n is infinity, the result is infinity |
| 1036 | */ |
| 1037 | if (tn & VFP_INFINITY) |
| 1038 | goto infinity; |
| 1039 | |
| 1040 | /* |
| 1041 | * If m is zero, raise div0 exceptions |
| 1042 | */ |
| 1043 | if (tm & VFP_ZERO) |
| 1044 | goto divzero; |
| 1045 | |
| 1046 | /* |
| 1047 | * If m is infinity, or n is zero, the result is zero |
| 1048 | */ |
| 1049 | if (tm & VFP_INFINITY || tn & VFP_ZERO) |
| 1050 | goto zero; |
| 1051 | |
| 1052 | if (tn & VFP_DENORMAL) |
| 1053 | vfp_double_normalise_denormal(&vdn); |
| 1054 | if (tm & VFP_DENORMAL) |
| 1055 | vfp_double_normalise_denormal(&vdm); |
| 1056 | |
| 1057 | /* |
| 1058 | * Ok, we have two numbers, we can perform division. |
| 1059 | */ |
| 1060 | vdd.exponent = vdn.exponent - vdm.exponent + 1023 - 1; |
| 1061 | vdm.significand <<= 1; |
| 1062 | if (vdm.significand <= (2 * vdn.significand)) { |
| 1063 | vdn.significand >>= 1; |
| 1064 | vdd.exponent++; |
| 1065 | } |
| 1066 | vdd.significand = vfp_estimate_div128to64(vdn.significand, 0, vdm.significand); |
| 1067 | if ((vdd.significand & 0x1ff) <= 2) { |
| 1068 | u64 termh, terml, remh, reml; |
| 1069 | mul64to128(&termh, &terml, vdm.significand, vdd.significand); |
| 1070 | sub128(&remh, &reml, vdn.significand, 0, termh, terml); |
| 1071 | while ((s64)remh < 0) { |
| 1072 | vdd.significand -= 1; |
| 1073 | add128(&remh, &reml, remh, reml, 0, vdm.significand); |
| 1074 | } |
| 1075 | vdd.significand |= (reml != 0); |
| 1076 | } |
| 1077 | return vfp_double_normaliseround(dd, &vdd, fpscr, 0, "fdiv"); |
| 1078 | |
| 1079 | vdn_nan: |
| 1080 | exceptions = vfp_propagate_nan(&vdd, &vdn, &vdm, fpscr); |
| 1081 | pack: |
| 1082 | vfp_put_double(dd, vfp_double_pack(&vdd)); |
| 1083 | return exceptions; |
| 1084 | |
| 1085 | vdm_nan: |
| 1086 | exceptions = vfp_propagate_nan(&vdd, &vdm, &vdn, fpscr); |
| 1087 | goto pack; |
| 1088 | |
| 1089 | zero: |
| 1090 | vdd.exponent = 0; |
| 1091 | vdd.significand = 0; |
| 1092 | goto pack; |
| 1093 | |
| 1094 | divzero: |
| 1095 | exceptions = FPSCR_DZC; |
| 1096 | infinity: |
| 1097 | vdd.exponent = 2047; |
| 1098 | vdd.significand = 0; |
| 1099 | goto pack; |
| 1100 | |
| 1101 | invalid: |
| 1102 | vfp_put_double(dd, vfp_double_pack(&vfp_double_default_qnan)); |
| 1103 | return FPSCR_IOC; |
| 1104 | } |
| 1105 | |
| 1106 | static u32 (* const fop_fns[16])(int dd, int dn, int dm, u32 fpscr) = { |
| 1107 | [FOP_TO_IDX(FOP_FMAC)] = vfp_double_fmac, |
| 1108 | [FOP_TO_IDX(FOP_FNMAC)] = vfp_double_fnmac, |
| 1109 | [FOP_TO_IDX(FOP_FMSC)] = vfp_double_fmsc, |
| 1110 | [FOP_TO_IDX(FOP_FNMSC)] = vfp_double_fnmsc, |
| 1111 | [FOP_TO_IDX(FOP_FMUL)] = vfp_double_fmul, |
| 1112 | [FOP_TO_IDX(FOP_FNMUL)] = vfp_double_fnmul, |
| 1113 | [FOP_TO_IDX(FOP_FADD)] = vfp_double_fadd, |
| 1114 | [FOP_TO_IDX(FOP_FSUB)] = vfp_double_fsub, |
| 1115 | [FOP_TO_IDX(FOP_FDIV)] = vfp_double_fdiv, |
| 1116 | }; |
| 1117 | |
| 1118 | #define FREG_BANK(x) ((x) & 0x0c) |
| 1119 | #define FREG_IDX(x) ((x) & 3) |
| 1120 | |
| 1121 | u32 vfp_double_cpdo(u32 inst, u32 fpscr) |
| 1122 | { |
| 1123 | u32 op = inst & FOP_MASK; |
| 1124 | u32 exceptions = 0; |
| 1125 | unsigned int dd = vfp_get_sd(inst); |
| 1126 | unsigned int dn = vfp_get_sn(inst); |
| 1127 | unsigned int dm = vfp_get_sm(inst); |
| 1128 | unsigned int vecitr, veclen, vecstride; |
| 1129 | u32 (*fop)(int, int, s32, u32); |
| 1130 | |
| 1131 | veclen = fpscr & FPSCR_LENGTH_MASK; |
| 1132 | vecstride = (1 + ((fpscr & FPSCR_STRIDE_MASK) == FPSCR_STRIDE_MASK)) * 2; |
| 1133 | |
| 1134 | /* |
| 1135 | * If destination bank is zero, vector length is always '1'. |
| 1136 | * ARM DDI0100F C5.1.3, C5.3.2. |
| 1137 | */ |
| 1138 | if (FREG_BANK(dd) == 0) |
| 1139 | veclen = 0; |
| 1140 | |
| 1141 | pr_debug("VFP: vecstride=%u veclen=%u\n", vecstride, |
| 1142 | (veclen >> FPSCR_LENGTH_BIT) + 1); |
| 1143 | |
| 1144 | fop = (op == FOP_EXT) ? fop_extfns[dn] : fop_fns[FOP_TO_IDX(op)]; |
| 1145 | if (!fop) |
| 1146 | goto invalid; |
| 1147 | |
| 1148 | for (vecitr = 0; vecitr <= veclen; vecitr += 1 << FPSCR_LENGTH_BIT) { |
| 1149 | u32 except; |
| 1150 | |
| 1151 | if (op == FOP_EXT) |
| 1152 | pr_debug("VFP: itr%d (d%u.%u) = op[%u] (d%u.%u)\n", |
| 1153 | vecitr >> FPSCR_LENGTH_BIT, |
| 1154 | dd >> 1, dd & 1, dn, |
| 1155 | dm >> 1, dm & 1); |
| 1156 | else |
| 1157 | pr_debug("VFP: itr%d (d%u.%u) = (d%u.%u) op[%u] (d%u.%u)\n", |
| 1158 | vecitr >> FPSCR_LENGTH_BIT, |
| 1159 | dd >> 1, dd & 1, |
| 1160 | dn >> 1, dn & 1, |
| 1161 | FOP_TO_IDX(op), |
| 1162 | dm >> 1, dm & 1); |
| 1163 | |
| 1164 | except = fop(dd, dn, dm, fpscr); |
| 1165 | pr_debug("VFP: itr%d: exceptions=%08x\n", |
| 1166 | vecitr >> FPSCR_LENGTH_BIT, except); |
| 1167 | |
| 1168 | exceptions |= except; |
| 1169 | |
| 1170 | /* |
| 1171 | * This ensures that comparisons only operate on scalars; |
| 1172 | * comparisons always return with one FPSCR status bit set. |
| 1173 | */ |
| 1174 | if (except & (FPSCR_N|FPSCR_Z|FPSCR_C|FPSCR_V)) |
| 1175 | break; |
| 1176 | |
| 1177 | /* |
| 1178 | * CHECK: It appears to be undefined whether we stop when |
| 1179 | * we encounter an exception. We continue. |
| 1180 | */ |
| 1181 | |
| 1182 | dd = FREG_BANK(dd) + ((FREG_IDX(dd) + vecstride) & 6); |
| 1183 | dn = FREG_BANK(dn) + ((FREG_IDX(dn) + vecstride) & 6); |
| 1184 | if (FREG_BANK(dm) != 0) |
| 1185 | dm = FREG_BANK(dm) + ((FREG_IDX(dm) + vecstride) & 6); |
| 1186 | } |
| 1187 | return exceptions; |
| 1188 | |
| 1189 | invalid: |
| 1190 | return ~0; |
| 1191 | } |