Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1 | /* |
| 2 | * Linux/PA-RISC Project (http://www.parisc-linux.org/) |
| 3 | * |
| 4 | * Floating-point emulation code |
| 5 | * Copyright (C) 2001 Hewlett-Packard (Paul Bame) <bame@debian.org> |
| 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, or (at your option) |
| 10 | * 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, Boston, MA 02111-1307 USA |
| 20 | */ |
| 21 | /* |
| 22 | * BEGIN_DESC |
| 23 | * |
| 24 | * File: |
| 25 | * @(#) pa/spmath/fcnvfu.c $Revision: 1.1 $ |
| 26 | * |
| 27 | * Purpose: |
| 28 | * Floating-point to Unsigned Fixed-point Converts |
| 29 | * |
| 30 | * External Interfaces: |
| 31 | * dbl_to_dbl_fcnvfu(srcptr,nullptr,dstptr,status) |
| 32 | * dbl_to_sgl_fcnvfu(srcptr,nullptr,dstptr,status) |
| 33 | * sgl_to_dbl_fcnvfu(srcptr,nullptr,dstptr,status) |
| 34 | * sgl_to_sgl_fcnvfu(srcptr,nullptr,dstptr,status) |
| 35 | * |
| 36 | * Internal Interfaces: |
| 37 | * |
| 38 | * Theory: |
| 39 | * <<please update with a overview of the operation of this file>> |
| 40 | * |
| 41 | * END_DESC |
| 42 | */ |
| 43 | |
| 44 | |
| 45 | #include "float.h" |
| 46 | #include "sgl_float.h" |
| 47 | #include "dbl_float.h" |
| 48 | #include "cnv_float.h" |
| 49 | |
| 50 | /************************************************************************ |
| 51 | * Floating-point to Unsigned Fixed-point Converts * |
| 52 | ************************************************************************/ |
| 53 | |
| 54 | /* |
| 55 | * Single Floating-point to Single Unsigned Fixed |
| 56 | */ |
| 57 | /*ARGSUSED*/ |
| 58 | int |
| 59 | sgl_to_sgl_fcnvfu( |
| 60 | sgl_floating_point *srcptr, |
| 61 | unsigned int *nullptr, |
| 62 | unsigned int *dstptr, |
| 63 | unsigned int *status) |
| 64 | { |
| 65 | register unsigned int src, result; |
| 66 | register int src_exponent; |
| 67 | register boolean inexact = FALSE; |
| 68 | |
| 69 | src = *srcptr; |
| 70 | src_exponent = Sgl_exponent(src) - SGL_BIAS; |
| 71 | |
| 72 | /* |
| 73 | * Test for overflow |
| 74 | */ |
| 75 | if (src_exponent > SGL_FX_MAX_EXP + 1) { |
| 76 | if (Sgl_isone_sign(src)) { |
| 77 | result = 0; |
| 78 | } else { |
| 79 | result = 0xffffffff; |
| 80 | } |
| 81 | if (Is_invalidtrap_enabled()) { |
| 82 | return(INVALIDEXCEPTION); |
| 83 | } |
| 84 | Set_invalidflag(); |
| 85 | *dstptr = result; |
| 86 | return(NOEXCEPTION); |
| 87 | } |
| 88 | /* |
| 89 | * Generate result |
| 90 | */ |
| 91 | if (src_exponent >= 0) { |
| 92 | /* |
| 93 | * Check sign. |
| 94 | * If negative, trap unimplemented. |
| 95 | */ |
| 96 | if (Sgl_isone_sign(src)) { |
| 97 | result = 0; |
| 98 | if (Is_invalidtrap_enabled()) { |
| 99 | return(INVALIDEXCEPTION); |
| 100 | } |
| 101 | Set_invalidflag(); |
| 102 | *dstptr = result; |
| 103 | return(NOEXCEPTION); |
| 104 | } |
| 105 | Sgl_clear_signexponent_set_hidden(src); |
| 106 | Suint_from_sgl_mantissa(src,src_exponent,result); |
| 107 | |
| 108 | /* check for inexact */ |
| 109 | if (Sgl_isinexact_to_unsigned(src,src_exponent)) { |
| 110 | inexact = TRUE; |
| 111 | /* round result */ |
| 112 | switch (Rounding_mode()) { |
| 113 | case ROUNDPLUS: |
| 114 | result++; |
| 115 | break; |
| 116 | case ROUNDMINUS: /* never negative */ |
| 117 | break; |
| 118 | case ROUNDNEAREST: |
| 119 | if (Sgl_isone_roundbit(src,src_exponent) && |
| 120 | (Sgl_isone_stickybit(src,src_exponent) || |
| 121 | (result & 1))) { |
| 122 | result++; |
| 123 | } |
| 124 | break; |
| 125 | } |
| 126 | } |
| 127 | } else { |
| 128 | result = 0; |
| 129 | |
| 130 | /* check for inexact */ |
| 131 | if (Sgl_isnotzero_exponentmantissa(src)) { |
| 132 | inexact = TRUE; |
| 133 | /* round result */ |
| 134 | switch (Rounding_mode()) { |
| 135 | case ROUNDPLUS: |
| 136 | if (Sgl_iszero_sign(src)) { |
| 137 | result++; |
| 138 | } |
| 139 | break; |
| 140 | case ROUNDMINUS: |
| 141 | if (Sgl_isone_sign(src)) { |
| 142 | result = 0; |
| 143 | if (Is_invalidtrap_enabled()) { |
| 144 | return(INVALIDEXCEPTION); |
| 145 | } |
| 146 | Set_invalidflag(); |
| 147 | inexact = FALSE; |
| 148 | } |
| 149 | break; |
| 150 | case ROUNDNEAREST: |
| 151 | if (src_exponent == -1 && |
| 152 | Sgl_isnotzero_mantissa(src)) { |
| 153 | if (Sgl_isone_sign(src)) { |
| 154 | result = 0; |
| 155 | if (Is_invalidtrap_enabled()) { |
| 156 | return(INVALIDEXCEPTION); |
| 157 | } |
| 158 | Set_invalidflag(); |
| 159 | inexact = FALSE; |
| 160 | } |
| 161 | else result++; |
| 162 | } |
| 163 | break; |
| 164 | } |
| 165 | } |
| 166 | } |
| 167 | *dstptr = result; |
| 168 | if (inexact) { |
| 169 | if (Is_inexacttrap_enabled()) return(INEXACTEXCEPTION); |
| 170 | else Set_inexactflag(); |
| 171 | } |
| 172 | return(NOEXCEPTION); |
| 173 | } |
| 174 | |
| 175 | /* |
| 176 | * Single Floating-point to Double Unsigned Fixed |
| 177 | */ |
| 178 | /*ARGSUSED*/ |
| 179 | int |
| 180 | sgl_to_dbl_fcnvfu( |
| 181 | sgl_floating_point *srcptr, |
| 182 | unsigned int *nullptr, |
| 183 | dbl_unsigned *dstptr, |
| 184 | unsigned int *status) |
| 185 | { |
| 186 | register int src_exponent; |
| 187 | register unsigned int src, resultp1, resultp2; |
| 188 | register boolean inexact = FALSE; |
| 189 | |
| 190 | src = *srcptr; |
| 191 | src_exponent = Sgl_exponent(src) - SGL_BIAS; |
| 192 | |
| 193 | /* |
| 194 | * Test for overflow |
| 195 | */ |
| 196 | if (src_exponent > DBL_FX_MAX_EXP + 1) { |
| 197 | if (Sgl_isone_sign(src)) { |
| 198 | resultp1 = resultp2 = 0; |
| 199 | } else { |
| 200 | resultp1 = resultp2 = 0xffffffff; |
| 201 | } |
| 202 | if (Is_invalidtrap_enabled()) { |
| 203 | return(INVALIDEXCEPTION); |
| 204 | } |
| 205 | Set_invalidflag(); |
| 206 | Duint_copytoptr(resultp1,resultp2,dstptr); |
| 207 | return(NOEXCEPTION); |
| 208 | } |
| 209 | /* |
| 210 | * Generate result |
| 211 | */ |
| 212 | if (src_exponent >= 0) { |
| 213 | /* |
| 214 | * Check sign. |
| 215 | * If negative, trap unimplemented. |
| 216 | */ |
| 217 | if (Sgl_isone_sign(src)) { |
| 218 | resultp1 = resultp2 = 0; |
| 219 | if (Is_invalidtrap_enabled()) { |
| 220 | return(INVALIDEXCEPTION); |
| 221 | } |
| 222 | Set_invalidflag(); |
| 223 | Duint_copytoptr(resultp1,resultp2,dstptr); |
| 224 | return(NOEXCEPTION); |
| 225 | } |
| 226 | Sgl_clear_signexponent_set_hidden(src); |
| 227 | Duint_from_sgl_mantissa(src,src_exponent,resultp1,resultp2); |
| 228 | |
| 229 | /* check for inexact */ |
| 230 | if (Sgl_isinexact_to_unsigned(src,src_exponent)) { |
| 231 | inexact = TRUE; |
| 232 | /* round result */ |
| 233 | switch (Rounding_mode()) { |
| 234 | case ROUNDPLUS: |
| 235 | Duint_increment(resultp1,resultp2); |
| 236 | break; |
| 237 | case ROUNDMINUS: /* never negative */ |
| 238 | break; |
| 239 | case ROUNDNEAREST: |
| 240 | if (Sgl_isone_roundbit(src,src_exponent) && |
| 241 | (Sgl_isone_stickybit(src,src_exponent) || |
| 242 | Duint_isone_lowp2(resultp2))) { |
| 243 | Duint_increment(resultp1,resultp2); |
| 244 | } |
| 245 | break; |
| 246 | } |
| 247 | } |
| 248 | } else { |
| 249 | Duint_setzero(resultp1,resultp2); |
| 250 | |
| 251 | /* check for inexact */ |
| 252 | if (Sgl_isnotzero_exponentmantissa(src)) { |
| 253 | inexact = TRUE; |
| 254 | /* round result */ |
| 255 | switch (Rounding_mode()) { |
| 256 | case ROUNDPLUS: |
| 257 | if (Sgl_iszero_sign(src)) { |
| 258 | Duint_increment(resultp1,resultp2); |
| 259 | } |
| 260 | break; |
| 261 | case ROUNDMINUS: |
| 262 | if (Sgl_isone_sign(src)) { |
| 263 | resultp1 = resultp2 = 0; |
| 264 | if (Is_invalidtrap_enabled()) { |
| 265 | return(INVALIDEXCEPTION); |
| 266 | } |
| 267 | Set_invalidflag(); |
| 268 | inexact = FALSE; |
| 269 | } |
| 270 | break; |
| 271 | case ROUNDNEAREST: |
| 272 | if (src_exponent == -1 && |
| 273 | Sgl_isnotzero_mantissa(src)) { |
| 274 | if (Sgl_isone_sign(src)) { |
| 275 | resultp1 = 0; |
| 276 | resultp2 = 0; |
| 277 | if (Is_invalidtrap_enabled()) { |
| 278 | return(INVALIDEXCEPTION); |
| 279 | } |
| 280 | Set_invalidflag(); |
| 281 | inexact = FALSE; |
| 282 | } |
| 283 | else Duint_increment(resultp1,resultp2); |
| 284 | } |
| 285 | } |
| 286 | } |
| 287 | } |
| 288 | Duint_copytoptr(resultp1,resultp2,dstptr); |
| 289 | if (inexact) { |
| 290 | if (Is_inexacttrap_enabled()) return(INEXACTEXCEPTION); |
| 291 | else Set_inexactflag(); |
| 292 | } |
| 293 | return(NOEXCEPTION); |
| 294 | } |
| 295 | |
| 296 | /* |
| 297 | * Double Floating-point to Single Unsigned Fixed |
| 298 | */ |
| 299 | /*ARGSUSED*/ |
| 300 | int |
| 301 | dbl_to_sgl_fcnvfu (dbl_floating_point * srcptr, unsigned int *nullptr, |
| 302 | unsigned int *dstptr, unsigned int *status) |
| 303 | { |
| 304 | register unsigned int srcp1, srcp2, result; |
| 305 | register int src_exponent; |
| 306 | register boolean inexact = FALSE; |
| 307 | |
| 308 | Dbl_copyfromptr(srcptr,srcp1,srcp2); |
| 309 | src_exponent = Dbl_exponent(srcp1) - DBL_BIAS; |
| 310 | |
| 311 | /* |
| 312 | * Test for overflow |
| 313 | */ |
| 314 | if (src_exponent > SGL_FX_MAX_EXP + 1) { |
| 315 | if (Dbl_isone_sign(srcp1)) { |
| 316 | result = 0; |
| 317 | } else { |
| 318 | result = 0xffffffff; |
| 319 | } |
| 320 | if (Is_invalidtrap_enabled()) { |
| 321 | return(INVALIDEXCEPTION); |
| 322 | } |
| 323 | Set_invalidflag(); |
| 324 | *dstptr = result; |
| 325 | return(NOEXCEPTION); |
| 326 | } |
| 327 | /* |
| 328 | * Generate result |
| 329 | */ |
| 330 | if (src_exponent >= 0) { |
| 331 | /* |
| 332 | * Check sign. |
| 333 | * If negative, trap unimplemented. |
| 334 | */ |
| 335 | if (Dbl_isone_sign(srcp1)) { |
| 336 | result = 0; |
| 337 | if (Is_invalidtrap_enabled()) { |
| 338 | return(INVALIDEXCEPTION); |
| 339 | } |
| 340 | Set_invalidflag(); |
| 341 | *dstptr = result; |
| 342 | return(NOEXCEPTION); |
| 343 | } |
| 344 | Dbl_clear_signexponent_set_hidden(srcp1); |
| 345 | Suint_from_dbl_mantissa(srcp1,srcp2,src_exponent,result); |
| 346 | |
| 347 | /* check for inexact */ |
| 348 | if (Dbl_isinexact_to_unsigned(srcp1,srcp2,src_exponent)) { |
| 349 | inexact = TRUE; |
| 350 | /* round result */ |
| 351 | switch (Rounding_mode()) { |
| 352 | case ROUNDPLUS: |
| 353 | result++; |
| 354 | break; |
| 355 | case ROUNDMINUS: /* never negative */ |
| 356 | break; |
| 357 | case ROUNDNEAREST: |
| 358 | if(Dbl_isone_roundbit(srcp1,srcp2,src_exponent) && |
| 359 | (Dbl_isone_stickybit(srcp1,srcp2,src_exponent)|| |
| 360 | result&1)) |
| 361 | result++; |
| 362 | break; |
| 363 | } |
| 364 | /* check for overflow */ |
| 365 | if (result == 0) { |
| 366 | result = 0xffffffff; |
| 367 | if (Is_invalidtrap_enabled()) { |
| 368 | return(INVALIDEXCEPTION); |
| 369 | } |
| 370 | Set_invalidflag(); |
| 371 | *dstptr = result; |
| 372 | return(NOEXCEPTION); |
| 373 | } |
| 374 | } |
| 375 | } else { |
| 376 | result = 0; |
| 377 | |
| 378 | /* check for inexact */ |
| 379 | if (Dbl_isnotzero_exponentmantissa(srcp1,srcp2)) { |
| 380 | inexact = TRUE; |
| 381 | /* round result */ |
| 382 | switch (Rounding_mode()) { |
| 383 | case ROUNDPLUS: |
| 384 | if (Dbl_iszero_sign(srcp1)) result++; |
| 385 | break; |
| 386 | case ROUNDMINUS: |
| 387 | if (Dbl_isone_sign(srcp1)) { |
| 388 | result = 0; |
| 389 | if (Is_invalidtrap_enabled()) { |
| 390 | return(INVALIDEXCEPTION); |
| 391 | } |
| 392 | Set_invalidflag(); |
| 393 | inexact = FALSE; |
| 394 | } |
| 395 | break; |
| 396 | case ROUNDNEAREST: |
| 397 | if (src_exponent == -1 && |
| 398 | Dbl_isnotzero_mantissa(srcp1,srcp2)) |
| 399 | if (Dbl_isone_sign(srcp1)) { |
| 400 | result = 0; |
| 401 | if (Is_invalidtrap_enabled()) { |
| 402 | return(INVALIDEXCEPTION); |
| 403 | } |
| 404 | Set_invalidflag(); |
| 405 | inexact = FALSE; |
| 406 | } |
| 407 | else result++; |
| 408 | } |
| 409 | } |
| 410 | } |
| 411 | *dstptr = result; |
| 412 | if (inexact) { |
| 413 | if (Is_inexacttrap_enabled()) return(INEXACTEXCEPTION); |
| 414 | else Set_inexactflag(); |
| 415 | } |
| 416 | return(NOEXCEPTION); |
| 417 | } |
| 418 | |
| 419 | /* |
| 420 | * Double Floating-point to Double Unsigned Fixed |
| 421 | */ |
| 422 | /*ARGSUSED*/ |
| 423 | int |
| 424 | dbl_to_dbl_fcnvfu (dbl_floating_point * srcptr, unsigned int *nullptr, |
| 425 | dbl_unsigned * dstptr, unsigned int *status) |
| 426 | { |
| 427 | register int src_exponent; |
| 428 | register unsigned int srcp1, srcp2, resultp1, resultp2; |
| 429 | register boolean inexact = FALSE; |
| 430 | |
| 431 | Dbl_copyfromptr(srcptr,srcp1,srcp2); |
| 432 | src_exponent = Dbl_exponent(srcp1) - DBL_BIAS; |
| 433 | |
| 434 | /* |
| 435 | * Test for overflow |
| 436 | */ |
| 437 | if (src_exponent > DBL_FX_MAX_EXP + 1) { |
| 438 | if (Dbl_isone_sign(srcp1)) { |
| 439 | resultp1 = resultp2 = 0; |
| 440 | } else { |
| 441 | resultp1 = resultp2 = 0xffffffff; |
| 442 | } |
| 443 | if (Is_invalidtrap_enabled()) { |
| 444 | return(INVALIDEXCEPTION); |
| 445 | } |
| 446 | Set_invalidflag(); |
| 447 | Duint_copytoptr(resultp1,resultp2,dstptr); |
| 448 | return(NOEXCEPTION); |
| 449 | } |
| 450 | |
| 451 | /* |
| 452 | * Generate result |
| 453 | */ |
| 454 | if (src_exponent >= 0) { |
| 455 | /* |
| 456 | * Check sign. |
| 457 | * If negative, trap unimplemented. |
| 458 | */ |
| 459 | if (Dbl_isone_sign(srcp1)) { |
| 460 | resultp1 = resultp2 = 0; |
| 461 | if (Is_invalidtrap_enabled()) { |
| 462 | return(INVALIDEXCEPTION); |
| 463 | } |
| 464 | Set_invalidflag(); |
| 465 | Duint_copytoptr(resultp1,resultp2,dstptr); |
| 466 | return(NOEXCEPTION); |
| 467 | } |
| 468 | Dbl_clear_signexponent_set_hidden(srcp1); |
| 469 | Duint_from_dbl_mantissa(srcp1,srcp2,src_exponent,resultp1, |
| 470 | resultp2); |
| 471 | |
| 472 | /* check for inexact */ |
| 473 | if (Dbl_isinexact_to_unsigned(srcp1,srcp2,src_exponent)) { |
| 474 | inexact = TRUE; |
| 475 | /* round result */ |
| 476 | switch (Rounding_mode()) { |
| 477 | case ROUNDPLUS: |
| 478 | Duint_increment(resultp1,resultp2); |
| 479 | break; |
| 480 | case ROUNDMINUS: /* never negative */ |
| 481 | break; |
| 482 | case ROUNDNEAREST: |
| 483 | if(Dbl_isone_roundbit(srcp1,srcp2,src_exponent)) |
| 484 | if(Dbl_isone_stickybit(srcp1,srcp2,src_exponent) || |
| 485 | Duint_isone_lowp2(resultp2)) |
| 486 | Duint_increment(resultp1,resultp2); |
| 487 | } |
| 488 | } |
| 489 | } else { |
| 490 | Duint_setzero(resultp1,resultp2); |
| 491 | |
| 492 | /* check for inexact */ |
| 493 | if (Dbl_isnotzero_exponentmantissa(srcp1,srcp2)) { |
| 494 | inexact = TRUE; |
| 495 | /* round result */ |
| 496 | switch (Rounding_mode()) { |
| 497 | case ROUNDPLUS: |
| 498 | if (Dbl_iszero_sign(srcp1)) { |
| 499 | Duint_increment(resultp1,resultp2); |
| 500 | } |
| 501 | break; |
| 502 | case ROUNDMINUS: |
| 503 | if (Dbl_isone_sign(srcp1)) { |
| 504 | resultp1 = resultp2 = 0; |
| 505 | if (Is_invalidtrap_enabled()) { |
| 506 | return(INVALIDEXCEPTION); |
| 507 | } |
| 508 | Set_invalidflag(); |
| 509 | inexact = FALSE; |
| 510 | } |
| 511 | break; |
| 512 | case ROUNDNEAREST: |
| 513 | if (src_exponent == -1 && |
| 514 | Dbl_isnotzero_mantissa(srcp1,srcp2)) |
| 515 | if (Dbl_iszero_sign(srcp1)) { |
| 516 | Duint_increment(resultp1,resultp2); |
| 517 | } else { |
| 518 | resultp1 = 0; |
| 519 | resultp2 = 0; |
| 520 | if (Is_invalidtrap_enabled()) { |
| 521 | return(INVALIDEXCEPTION); |
| 522 | } |
| 523 | Set_invalidflag(); |
| 524 | inexact = FALSE; |
| 525 | } |
| 526 | } |
| 527 | } |
| 528 | } |
| 529 | Duint_copytoptr(resultp1,resultp2,dstptr); |
| 530 | if (inexact) { |
| 531 | if (Is_inexacttrap_enabled()) return(INEXACTEXCEPTION); |
| 532 | else Set_inexactflag(); |
| 533 | } |
| 534 | return(NOEXCEPTION); |
| 535 | } |
| 536 | |