1 /* $NetBSD: ieee754io.c,v 1.1.1.1 2009/12/13 16:55:22 kardel Exp $ */ 2 3 /* 4 * /src/NTP/ntp4-dev/libntp/ieee754io.c,v 4.12 2005/04/16 17:32:10 kardel RELEASE_20050508_A 5 * 6 * ieee754io.c,v 4.12 2005/04/16 17:32:10 kardel RELEASE_20050508_A 7 * 8 * Created: Sun Jul 13 09:12:02 1997 9 * 10 * Copyright (c) 1997-2005 by Frank Kardel <kardel <AT> ntp.org> 11 * 12 * Redistribution and use in source and binary forms, with or without 13 * modification, are permitted provided that the following conditions 14 * are met: 15 * 1. Redistributions of source code must retain the above copyright 16 * notice, this list of conditions and the following disclaimer. 17 * 2. Redistributions in binary form must reproduce the above copyright 18 * notice, this list of conditions and the following disclaimer in the 19 * documentation and/or other materials provided with the distribution. 20 * 3. Neither the name of the author nor the names of its contributors 21 * may be used to endorse or promote products derived from this software 22 * without specific prior written permission. 23 * 24 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 25 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 26 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 27 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 28 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 29 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 30 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 31 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 32 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 33 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 34 * SUCH DAMAGE. 35 * 36 */ 37 38 #ifdef HAVE_CONFIG_H 39 #include "config.h" 40 #endif 41 42 #include <stdio.h> 43 #include "l_stdlib.h" 44 #include "ntp_stdlib.h" 45 #include "ntp_fp.h" 46 #include "ieee754io.h" 47 48 static unsigned char get_byte (unsigned char *, offsets_t, int *); 49 #ifdef __not_yet__ 50 static void put_byte (unsigned char *, offsets_t, int *, unsigned char); 51 #endif 52 53 #ifdef LIBDEBUG 54 55 #include "lib_strbuf.h" 56 57 static char * 58 fmt_blong( 59 unsigned long val, 60 int cnt 61 ) 62 { 63 char *buf, *s; 64 int i = cnt; 65 66 val <<= 32 - cnt; 67 LIB_GETBUF(buf); 68 s = buf; 69 70 while (i--) 71 { 72 if (val & 0x80000000) 73 { 74 *s++ = '1'; 75 } 76 else 77 { 78 *s++ = '0'; 79 } 80 val <<= 1; 81 } 82 *s = '\0'; 83 return buf; 84 } 85 86 static char * 87 fmt_flt( 88 unsigned int sign, 89 unsigned long mh, 90 unsigned long ml, 91 unsigned long ch 92 ) 93 { 94 char *buf; 95 96 LIB_GETBUF(buf); 97 sprintf(buf, "%c %s %s %s", sign ? '-' : '+', 98 fmt_blong(ch, 11), 99 fmt_blong(mh, 20), 100 fmt_blong(ml, 32)); 101 return buf; 102 } 103 104 static char * 105 fmt_hex( 106 unsigned char *bufp, 107 int length 108 ) 109 { 110 char *buf; 111 int i; 112 113 LIB_GETBUF(buf); 114 for (i = 0; i < length; i++) 115 { 116 sprintf(buf+i*2, "%02x", bufp[i]); 117 } 118 return buf; 119 } 120 121 #endif 122 123 static unsigned char 124 get_byte( 125 unsigned char *bufp, 126 offsets_t offset, 127 int *fieldindex 128 ) 129 { 130 unsigned char val; 131 132 val = *(bufp + offset[*fieldindex]); 133 #ifdef LIBDEBUG 134 if (debug > 4) 135 printf("fetchieee754: getbyte(0x%08x, %d) = 0x%02x\n", (unsigned int)(bufp)+offset[*fieldindex], *fieldindex, val); 136 #endif 137 (*fieldindex)++; 138 return val; 139 } 140 141 #ifdef __not_yet__ 142 static void 143 put_byte( 144 unsigned char *bufp, 145 offsets_t offsets, 146 int *fieldindex, 147 unsigned char val 148 ) 149 { 150 *(bufp + offsets[*fieldindex]) = val; 151 (*fieldindex)++; 152 } 153 #endif 154 155 /* 156 * make conversions to and from external IEEE754 formats and internal 157 * NTP FP format. 158 */ 159 int 160 fetch_ieee754( 161 unsigned char **buffpp, 162 int size, 163 l_fp *lfpp, 164 offsets_t offsets 165 ) 166 { 167 unsigned char *bufp = *buffpp; 168 unsigned int sign; 169 unsigned int bias; 170 unsigned int maxexp; 171 int mbits; 172 u_long mantissa_low; 173 u_long mantissa_high; 174 u_long characteristic; 175 long exponent; 176 #ifdef LIBDEBUG 177 int length; 178 #endif 179 unsigned char val; 180 int fieldindex = 0; 181 182 switch (size) 183 { 184 case IEEE_DOUBLE: 185 #ifdef LIBDEBUG 186 length = 8; 187 #endif 188 mbits = 52; 189 bias = 1023; 190 maxexp = 2047; 191 break; 192 193 case IEEE_SINGLE: 194 #ifdef LIBDEBUG 195 length = 4; 196 #endif 197 mbits = 23; 198 bias = 127; 199 maxexp = 255; 200 break; 201 202 default: 203 return IEEE_BADCALL; 204 } 205 206 val = get_byte(bufp, offsets, &fieldindex); /* fetch sign byte & first part of characteristic */ 207 208 sign = (val & 0x80) != 0; 209 characteristic = (val & 0x7F); 210 211 val = get_byte(bufp, offsets, &fieldindex); /* fetch rest of characteristic and start of mantissa */ 212 213 switch (size) 214 { 215 case IEEE_SINGLE: 216 characteristic <<= 1; 217 characteristic |= (val & 0x80) != 0; /* grab last characteristic bit */ 218 219 mantissa_high = 0; 220 221 mantissa_low = (val &0x7F) << 16; 222 mantissa_low |= get_byte(bufp, offsets, &fieldindex) << 8; 223 mantissa_low |= get_byte(bufp, offsets, &fieldindex); 224 break; 225 226 case IEEE_DOUBLE: 227 characteristic <<= 4; 228 characteristic |= (val & 0xF0) >> 4; /* grab lower characteristic bits */ 229 230 mantissa_high = (val & 0x0F) << 16; 231 mantissa_high |= get_byte(bufp, offsets, &fieldindex) << 8; 232 mantissa_high |= get_byte(bufp, offsets, &fieldindex); 233 234 mantissa_low = get_byte(bufp, offsets, &fieldindex) << 24; 235 mantissa_low |= get_byte(bufp, offsets, &fieldindex) << 16; 236 mantissa_low |= get_byte(bufp, offsets, &fieldindex) << 8; 237 mantissa_low |= get_byte(bufp, offsets, &fieldindex); 238 break; 239 240 default: 241 return IEEE_BADCALL; 242 } 243 #ifdef LIBDEBUG 244 if (debug > 4) 245 { 246 double d; 247 float f; 248 249 if (size == IEEE_SINGLE) 250 { 251 int i; 252 253 for (i = 0; i < length; i++) 254 { 255 *((unsigned char *)(&f)+i) = *(*buffpp + offsets[i]); 256 } 257 d = f; 258 } 259 else 260 { 261 int i; 262 263 for (i = 0; i < length; i++) 264 { 265 *((unsigned char *)(&d)+i) = *(*buffpp + offsets[i]); 266 } 267 } 268 269 printf("fetchieee754: FP: %s -> %s -> %e(=%s)\n", fmt_hex(*buffpp, length), 270 fmt_flt(sign, mantissa_high, mantissa_low, characteristic), 271 d, fmt_hex((unsigned char *)&d, length)); 272 } 273 #endif 274 275 *buffpp += fieldindex; 276 277 /* 278 * detect funny numbers 279 */ 280 if (characteristic == maxexp) 281 { 282 /* 283 * NaN or Infinity 284 */ 285 if (mantissa_low || mantissa_high) 286 { 287 /* 288 * NaN 289 */ 290 return IEEE_NAN; 291 } 292 else 293 { 294 /* 295 * +Inf or -Inf 296 */ 297 return sign ? IEEE_NEGINFINITY : IEEE_POSINFINITY; 298 } 299 } 300 else 301 { 302 /* 303 * collect real numbers 304 */ 305 306 L_CLR(lfpp); 307 308 /* 309 * check for overflows 310 */ 311 exponent = characteristic - bias; 312 313 if (exponent > 31) /* sorry - hardcoded */ 314 { 315 /* 316 * overflow only in respect to NTP-FP representation 317 */ 318 return sign ? IEEE_NEGOVERFLOW : IEEE_POSOVERFLOW; 319 } 320 else 321 { 322 int frac_offset; /* where the fraction starts */ 323 324 frac_offset = mbits - exponent; 325 326 if (characteristic == 0) 327 { 328 /* 329 * de-normalized or tiny number - fits only as 0 330 */ 331 return IEEE_OK; 332 } 333 else 334 { 335 /* 336 * adjust for implied 1 337 */ 338 if (mbits > 31) 339 mantissa_high |= 1 << (mbits - 32); 340 else 341 mantissa_low |= 1 << mbits; 342 343 /* 344 * take mantissa apart - if only all machine would support 345 * 64 bit operations 8-( 346 */ 347 if (frac_offset > mbits) 348 { 349 lfpp->l_ui = 0; /* only fractional number */ 350 frac_offset -= mbits + 1; /* will now contain right shift count - 1*/ 351 if (mbits > 31) 352 { 353 lfpp->l_uf = mantissa_high << (63 - mbits); 354 lfpp->l_uf |= mantissa_low >> (mbits - 33); 355 lfpp->l_uf >>= frac_offset; 356 } 357 else 358 { 359 lfpp->l_uf = mantissa_low >> frac_offset; 360 } 361 } 362 else 363 { 364 if (frac_offset > 32) 365 { 366 /* 367 * must split in high word 368 */ 369 lfpp->l_ui = mantissa_high >> (frac_offset - 32); 370 lfpp->l_uf = (mantissa_high & ((1 << (frac_offset - 32)) - 1)) << (64 - frac_offset); 371 lfpp->l_uf |= mantissa_low >> (frac_offset - 32); 372 } 373 else 374 { 375 /* 376 * must split in low word 377 */ 378 lfpp->l_ui = mantissa_high << (32 - frac_offset); 379 lfpp->l_ui |= (mantissa_low >> frac_offset) & ((1 << (32 - frac_offset)) - 1); 380 lfpp->l_uf = (mantissa_low & ((1 << frac_offset) - 1)) << (32 - frac_offset); 381 } 382 } 383 384 /* 385 * adjust for sign 386 */ 387 if (sign) 388 { 389 L_NEG(lfpp); 390 } 391 392 return IEEE_OK; 393 } 394 } 395 } 396 } 397 398 int 399 put_ieee754( 400 unsigned char **bufpp, 401 int size, 402 l_fp *lfpp, 403 offsets_t offsets 404 ) 405 { 406 l_fp outlfp; 407 #ifdef LIBDEBUG 408 unsigned int sign; 409 unsigned int bias; 410 #endif 411 /*unsigned int maxexp;*/ 412 int mbits; 413 int msb; 414 u_long mantissa_low = 0; 415 u_long mantissa_high = 0; 416 #ifdef LIBDEBUG 417 u_long characteristic = 0; 418 long exponent; 419 #endif 420 /*int length;*/ 421 unsigned long mask; 422 423 outlfp = *lfpp; 424 425 switch (size) 426 { 427 case IEEE_DOUBLE: 428 /*length = 8;*/ 429 mbits = 52; 430 #ifdef LIBDEBUG 431 bias = 1023; 432 #endif 433 /*maxexp = 2047;*/ 434 break; 435 436 case IEEE_SINGLE: 437 /*length = 4;*/ 438 mbits = 23; 439 #ifdef LIBDEBUG 440 bias = 127; 441 #endif 442 /*maxexp = 255;*/ 443 break; 444 445 default: 446 return IEEE_BADCALL; 447 } 448 449 /* 450 * find sign 451 */ 452 if (L_ISNEG(&outlfp)) 453 { 454 L_NEG(&outlfp); 455 #ifdef LIBDEBUG 456 sign = 1; 457 #endif 458 } 459 else 460 { 461 #ifdef LIBDEBUG 462 sign = 0; 463 #endif 464 } 465 466 if (L_ISZERO(&outlfp)) 467 { 468 #ifdef LIBDEBUG 469 exponent = mantissa_high = mantissa_low = 0; /* true zero */ 470 #endif 471 } 472 else 473 { 474 /* 475 * find number of significant integer bits 476 */ 477 mask = 0x80000000; 478 if (outlfp.l_ui) 479 { 480 msb = 63; 481 while (mask && ((outlfp.l_ui & mask) == 0)) 482 { 483 mask >>= 1; 484 msb--; 485 } 486 } 487 else 488 { 489 msb = 31; 490 while (mask && ((outlfp.l_uf & mask) == 0)) 491 { 492 mask >>= 1; 493 msb--; 494 } 495 } 496 497 switch (size) 498 { 499 case IEEE_SINGLE: 500 mantissa_high = 0; 501 if (msb >= 32) 502 { 503 mantissa_low = (outlfp.l_ui & ((1 << (msb - 32)) - 1)) << (mbits - (msb - 32)); 504 mantissa_low |= outlfp.l_uf >> (mbits - (msb - 32)); 505 } 506 else 507 { 508 mantissa_low = (outlfp.l_uf << (mbits - msb)) & ((1 << mbits) - 1); 509 } 510 break; 511 512 case IEEE_DOUBLE: 513 if (msb >= 32) 514 { 515 mantissa_high = (outlfp.l_ui << (mbits - msb)) & ((1 << (mbits - 32)) - 1); 516 mantissa_high |= outlfp.l_uf >> (32 - (mbits - msb)); 517 mantissa_low = (outlfp.l_ui & ((1 << (msb - mbits)) - 1)) << (32 - (msb - mbits)); 518 mantissa_low |= outlfp.l_uf >> (msb - mbits); 519 } 520 else 521 { 522 mantissa_high = outlfp.l_uf << (mbits - 32 - msb); 523 mantissa_low = outlfp.l_uf << (mbits - 32); 524 } 525 } 526 527 #ifdef LIBDEBUG 528 exponent = msb - 32; 529 characteristic = exponent + bias; 530 531 if (debug > 4) 532 printf("FP: %s\n", fmt_flt(sign, mantissa_high, mantissa_low, characteristic)); 533 #endif 534 } 535 return IEEE_OK; 536 } 537 538 539 #if defined(DEBUG) && defined(LIBDEBUG) 540 int main( 541 int argc, 542 char **argv 543 ) 544 { 545 static offsets_t native_off = { 0, 1, 2, 3, 4, 5, 6, 7 }; 546 double f = 1.0; 547 double *f_p = &f; 548 l_fp fp; 549 550 if (argc == 2) 551 { 552 if (sscanf(argv[1], "%lf", &f) != 1) 553 { 554 printf("cannot convert %s to a float\n", argv[1]); 555 return 1; 556 } 557 } 558 559 printf("double: %s %s\n", fmt_blong(*(unsigned long *)&f, 32), fmt_blong(*(unsigned long *)((char *)(&f)+4), 32)); 560 printf("fetch from %f = %d\n", f, fetch_ieee754((void *)&f_p, IEEE_DOUBLE, &fp, native_off)); 561 printf("fp [%s %s] = %s\n", fmt_blong(fp.l_ui, 32), fmt_blong(fp.l_uf, 32), mfptoa(fp.l_ui, fp.l_uf, 15)); 562 f_p = &f; 563 put_ieee754((void *)&f_p, IEEE_DOUBLE, &fp, native_off); 564 565 return 0; 566 } 567 568 #endif 569 /* 570 * History: 571 * 572 * ieee754io.c,v 573 * Revision 4.12 2005/04/16 17:32:10 kardel 574 * update copyright 575 * 576 * Revision 4.11 2004/11/14 15:29:41 kardel 577 * support PPSAPI, upgrade Copyright to Berkeley style 578 * 579 * Revision 4.8 1999/02/21 12:17:36 kardel 580 * 4.91f reconcilation 581 * 582 * Revision 4.7 1999/02/21 11:26:03 kardel 583 * renamed index to fieldindex to avoid index() name clash 584 * 585 * Revision 4.6 1998/11/15 20:27:52 kardel 586 * Release 4.0.73e13 reconcilation 587 * 588 * Revision 4.5 1998/08/16 19:01:51 kardel 589 * debug information only compile for LIBDEBUG case 590 * 591 * Revision 4.4 1998/08/09 09:39:28 kardel 592 * Release 4.0.73e2 reconcilation 593 * 594 * Revision 4.3 1998/06/13 11:56:19 kardel 595 * disabled putbute() for the time being 596 * 597 * Revision 4.2 1998/06/12 15:16:58 kardel 598 * ansi2knr compatibility 599 * 600 * Revision 4.1 1998/05/24 07:59:56 kardel 601 * conditional debug support 602 * 603 * Revision 4.0 1998/04/10 19:46:29 kardel 604 * Start 4.0 release version numbering 605 * 606 * Revision 1.1 1998/04/10 19:27:46 kardel 607 * initial NTP VERSION 4 integration of PARSE with GPS166 binary support 608 * 609 * Revision 1.1 1997/10/06 21:05:45 kardel 610 * new parse structure 611 * 612 */ 613