external/bsd/ntp/dist/include/ntp_fp.h

   1 /*      $NetBSD$        */
   2
   3 /*
   4  * ntp_fp.h - definitions for NTP fixed/floating-point arithmetic
   5  */
   6
   7 #ifndef NTP_FP_H
   8 #define NTP_FP_H
   9
  10 #include "ntp_types.h"
  11
  12 /*
  13  * NTP uses two fixed point formats.  The first (l_fp) is the "long"
  14  * format and is 64 bits long with the decimal between bits 31 and 32.
  15  * This is used for time stamps in the NTP packet header (in network
  16  * byte order) and for internal computations of offsets (in local host
  17  * byte order). We use the same structure for both signed and unsigned
  18  * values, which is a big hack but saves rewriting all the operators
  19  * twice. Just to confuse this, we also sometimes just carry the
  20  * fractional part in calculations, in both signed and unsigned forms.
  21  * Anyway, an l_fp looks like:
  22  *
  23  *    0                   1                   2                   3
  24  *    0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
  25  *   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
  26  *   |                         Integral Part                         |
  27  *   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
  28  *   |                         Fractional Part                       |
  29  *   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
  30  *
  31  */
  32 typedef struct {
  33         union {
  34                 u_int32 Xl_ui;
  35                 int32 Xl_i;
  36         } Ul_i;
  37         union {
  38                 u_int32 Xl_uf;
  39                 int32 Xl_f;
  40         } Ul_f;
  41 } l_fp;
  42
  43 #define l_ui    Ul_i.Xl_ui              /* unsigned integral part */
  44 #define l_i     Ul_i.Xl_i               /* signed integral part */
  45 #define l_uf    Ul_f.Xl_uf              /* unsigned fractional part */
  46 #define l_f     Ul_f.Xl_f               /* signed fractional part */
  47
  48 /*
  49  * Fractional precision (of an l_fp) is actually the number of
  50  * bits in a long.
  51  */
  52 #define FRACTION_PREC   (32)
  53
  54
  55 /*
  56  * The second fixed point format is 32 bits, with the decimal between
  57  * bits 15 and 16.  There is a signed version (s_fp) and an unsigned
  58  * version (u_fp).  This is used to represent synchronizing distance
  59  * and synchronizing dispersion in the NTP packet header (again, in
  60  * network byte order) and internally to hold both distance and
  61  * dispersion values (in local byte order).  In network byte order
  62  * it looks like:
  63  *
  64  *    0                   1                   2                   3
  65  *    0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
  66  *   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
  67  *   |            Integer Part       |     Fraction Part             |
  68  *   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
  69  *
  70  */
  71 typedef int32 s_fp;
  72 typedef u_int32 u_fp;
  73
  74 /*
  75  * A unit second in fp format.  Actually 2**(half_the_bits_in_a_long)
  76  */
  77 #define FP_SECOND       (0x10000)
  78
  79 /*
  80  * Byte order conversions
  81  */
  82 #define HTONS_FP(x)     (htonl(x))
  83 #define HTONL_FP(h, n)  do { (n)->l_ui = htonl((h)->l_ui); \
  84                              (n)->l_uf = htonl((h)->l_uf); } while (0)
  85 #define NTOHS_FP(x)     (ntohl(x))
  86 #define NTOHL_FP(n, h)  do { (h)->l_ui = ntohl((n)->l_ui); \
  87                              (h)->l_uf = ntohl((n)->l_uf); } while (0)
  88 #define NTOHL_MFP(ni, nf, hi, hf) \
  89         do { (hi) = ntohl(ni); (hf) = ntohl(nf); } while (0)
  90 #define HTONL_MFP(hi, hf, ni, nf) \
  91         do { (ni) = ntohl(hi); (nf) = ntohl(hf); } while (0)
  92
  93 /* funny ones.  Converts ts fractions to net order ts */
  94 #define HTONL_UF(uf, nts) \
  95         do { (nts)->l_ui = 0; (nts)->l_uf = htonl(uf); } while (0)
  96 #define HTONL_F(f, nts) do { (nts)->l_uf = htonl(f); \
  97                                 if ((f) & 0x80000000) \
  98                                         (nts)->l_i = -1; \
  99                                 else \
 100                                         (nts)->l_i = 0; \
 101                         } while (0)
 102
 103 /*
 104  * Conversions between the two fixed point types
 105  */
 106 #define MFPTOFP(x_i, x_f)       (((x_i) >= 0x00010000) ? 0x7fffffff : \
 107                                 (((x_i) <= -0x00010000) ? 0x80000000 : \
 108                                 (((x_i)<<16) | (((x_f)>>16)&0xffff))))
 109 #define LFPTOFP(v)              MFPTOFP((v)->l_i, (v)->l_f)
 110
 111 #define UFPTOLFP(x, v) ((v)->l_ui = (u_fp)(x)>>16, (v)->l_uf = (x)<<16)
 112 #define FPTOLFP(x, v)  (UFPTOLFP((x), (v)), (x) < 0 ? (v)->l_ui -= 0x10000 : 0)
 113
 114 #define MAXLFP(v) ((v)->l_ui = 0x7fffffff, (v)->l_uf = 0xffffffff)
 115 #define MINLFP(v) ((v)->l_ui = 0x80000000, (v)->l_uf = 0)
 116
 117 /*
 118  * Primitive operations on long fixed point values.  If these are
 119  * reminiscent of assembler op codes it's only because some may
 120  * be replaced by inline assembler for particular machines someday.
 121  * These are the (kind of inefficient) run-anywhere versions.
 122  */
 123 #define M_NEG(v_i, v_f)         /* v = -v */ \
 124         do { \
 125                 if ((v_f) == 0) \
 126                         (v_i) = -((s_fp)(v_i)); \
 127                 else { \
 128                         (v_f) = -((s_fp)(v_f)); \
 129                         (v_i) = ~(v_i); \
 130                 } \
 131         } while(0)
 132
 133 #define M_NEGM(r_i, r_f, a_i, a_f)      /* r = -a */ \
 134         do { \
 135                 if ((a_f) == 0) { \
 136                         (r_f) = 0; \
 137                         (r_i) = -(a_i); \
 138                 } else { \
 139                         (r_f) = -(a_f); \
 140                         (r_i) = ~(a_i); \
 141                 } \
 142         } while(0)
 143
 144 #define M_ADD(r_i, r_f, a_i, a_f)       /* r += a */ \
 145         do { \
 146                 register u_int32 lo_tmp; \
 147                 register u_int32 hi_tmp; \
 148                 \
 149                 lo_tmp = ((r_f) & 0xffff) + ((a_f) & 0xffff); \
 150                 hi_tmp = (((r_f) >> 16) & 0xffff) + (((a_f) >> 16) & 0xffff); \
 151                 if (lo_tmp & 0x10000) \
 152                         hi_tmp++; \
 153                 (r_f) = ((hi_tmp & 0xffff) << 16) | (lo_tmp & 0xffff); \
 154                 \
 155                 (r_i) += (a_i); \
 156                 if (hi_tmp & 0x10000) \
 157                         (r_i)++; \
 158         } while (0)
 159
 160 #define M_ADD3(r_ovr, r_i, r_f, a_ovr, a_i, a_f) /* r += a, three word */ \
 161         do { \
 162                 register u_int32 lo_tmp; \
 163                 register u_int32 hi_tmp; \
 164                 \
 165                 lo_tmp = ((r_f) & 0xffff) + ((a_f) & 0xffff); \
 166                 hi_tmp = (((r_f) >> 16) & 0xffff) + (((a_f) >> 16) & 0xffff); \
 167                 if (lo_tmp & 0x10000) \
 168                         hi_tmp++; \
 169                 (r_f) = ((hi_tmp & 0xffff) << 16) | (lo_tmp & 0xffff); \
 170                 \
 171                 lo_tmp = ((r_i) & 0xffff) + ((a_i) & 0xffff); \
 172                 if (hi_tmp & 0x10000) \
 173                         lo_tmp++; \
 174                 hi_tmp = (((r_i) >> 16) & 0xffff) + (((a_i) >> 16) & 0xffff); \
 175                 if (lo_tmp & 0x10000) \
 176                         hi_tmp++; \
 177                 (r_i) = ((hi_tmp & 0xffff) << 16) | (lo_tmp & 0xffff); \
 178                 \
 179                 (r_ovr) += (a_ovr); \
 180                 if (hi_tmp & 0x10000) \
 181                         (r_ovr)++; \
 182         } while (0)
 183
 184 #define M_SUB(r_i, r_f, a_i, a_f)       /* r -= a */ \
 185         do { \
 186                 register u_int32 lo_tmp; \
 187                 register u_int32 hi_tmp; \
 188                 \
 189                 if ((a_f) == 0) { \
 190                         (r_i) -= (a_i); \
 191                 } else { \
 192                         lo_tmp = ((r_f) & 0xffff) + ((-((s_fp)(a_f))) & 0xffff); \
 193                         hi_tmp = (((r_f) >> 16) & 0xffff) \
 194                             + (((-((s_fp)(a_f))) >> 16) & 0xffff); \
 195                         if (lo_tmp & 0x10000) \
 196                                 hi_tmp++; \
 197                         (r_f) = ((hi_tmp & 0xffff) << 16) | (lo_tmp & 0xffff); \
 198                         \
 199                         (r_i) += ~(a_i); \
 200                         if (hi_tmp & 0x10000) \
 201                                 (r_i)++; \
 202                 } \
 203         } while (0)
 204
 205 #define M_RSHIFTU(v_i, v_f)             /* v >>= 1, v is unsigned */ \
 206         do { \
 207                 (v_f) = (u_int32)(v_f) >> 1; \
 208                 if ((v_i) & 01) \
 209                         (v_f) |= 0x80000000; \
 210                 (v_i) = (u_int32)(v_i) >> 1; \
 211         } while (0)
 212
 213 #define M_RSHIFT(v_i, v_f)              /* v >>= 1, v is signed */ \
 214         do { \
 215                 (v_f) = (u_int32)(v_f) >> 1; \
 216                 if ((v_i) & 01) \
 217                         (v_f) |= 0x80000000; \
 218                 if ((v_i) & 0x80000000) \
 219                         (v_i) = ((v_i) >> 1) | 0x80000000; \
 220                 else \
 221                         (v_i) = (v_i) >> 1; \
 222         } while (0)
 223
 224 #define M_LSHIFT(v_i, v_f)              /* v <<= 1 */ \
 225         do { \
 226                 (v_i) <<= 1; \
 227                 if ((v_f) & 0x80000000) \
 228                         (v_i) |= 0x1; \
 229                 (v_f) <<= 1; \
 230         } while (0)
 231
 232 #define M_LSHIFT3(v_ovr, v_i, v_f)      /* v <<= 1, with overflow */ \
 233         do { \
 234                 (v_ovr) <<= 1; \
 235                 if ((v_i) & 0x80000000) \
 236                         (v_ovr) |= 0x1; \
 237                 (v_i) <<= 1; \
 238                 if ((v_f) & 0x80000000) \
 239                         (v_i) |= 0x1; \
 240                 (v_f) <<= 1; \
 241         } while (0)
 242
 243 #define M_ADDUF(r_i, r_f, uf)           /* r += uf, uf is u_int32 fraction */ \
 244         M_ADD((r_i), (r_f), 0, (uf))    /* let optimizer worry about it */
 245
 246 #define M_SUBUF(r_i, r_f, uf)           /* r -= uf, uf is u_int32 fraction */ \
 247         M_SUB((r_i), (r_f), 0, (uf))    /* let optimizer worry about it */
 248
 249 #define M_ADDF(r_i, r_f, f)             /* r += f, f is a int32 fraction */ \
 250         do { \
 251                 if ((f) > 0) \
 252                         M_ADD((r_i), (r_f), 0, (f)); \
 253                 else if ((f) < 0) \
 254                         M_ADD((r_i), (r_f), (-1), (f));\
 255         } while(0)
 256
 257 #define M_ISNEG(v_i, v_f)               /* v < 0 */ \
 258         (((v_i) & 0x80000000) != 0)
 259
 260 #define M_ISHIS(a_i, a_f, b_i, b_f)     /* a >= b unsigned */ \
 261         (((u_int32)(a_i)) > ((u_int32)(b_i)) || \
 262           ((a_i) == (b_i) && ((u_int32)(a_f)) >= ((u_int32)(b_f))))
 263
 264 #define M_ISGEQ(a_i, a_f, b_i, b_f)     /* a >= b signed */ \
 265         (((int32)(a_i)) > ((int32)(b_i)) || \
 266           ((a_i) == (b_i) && ((u_int32)(a_f)) >= ((u_int32)(b_f))))
 267
 268 #define M_ISEQU(a_i, a_f, b_i, b_f)     /* a == b unsigned */ \
 269         ((a_i) == (b_i) && (a_f) == (b_f))
 270
 271 /*
 272  * Operations on the long fp format
 273  */
 274 #define L_ADD(r, a)     M_ADD((r)->l_ui, (r)->l_uf, (a)->l_ui, (a)->l_uf)
 275 #define L_SUB(r, a)     M_SUB((r)->l_ui, (r)->l_uf, (a)->l_ui, (a)->l_uf)
 276 #define L_NEG(v)        M_NEG((v)->l_ui, (v)->l_uf)
 277 #define L_ADDUF(r, uf)  M_ADDUF((r)->l_ui, (r)->l_uf, (uf))
 278 #define L_SUBUF(r, uf)  M_SUBUF((r)->l_ui, (r)->l_uf, (uf))
 279 #define L_ADDF(r, f)    M_ADDF((r)->l_ui, (r)->l_uf, (f))
 280 #define L_RSHIFT(v)     M_RSHIFT((v)->l_i, (v)->l_uf)
 281 #define L_RSHIFTU(v)    M_RSHIFTU((v)->l_ui, (v)->l_uf)
 282 #define L_LSHIFT(v)     M_LSHIFT((v)->l_ui, (v)->l_uf)
 283 #define L_CLR(v)        ((v)->l_ui = (v)->l_uf = 0)
 284
 285 #define L_ISNEG(v)      (((v)->l_ui & 0x80000000) != 0)
 286 #define L_ISZERO(v)     ((v)->l_ui == 0 && (v)->l_uf == 0)
 287 #define L_ISHIS(a, b)   ((a)->l_ui > (b)->l_ui || \
 288                           ((a)->l_ui == (b)->l_ui && (a)->l_uf >= (b)->l_uf))
 289 #define L_ISGEQ(a, b)   ((a)->l_i > (b)->l_i || \
 290                           ((a)->l_i == (b)->l_i && (a)->l_uf >= (b)->l_uf))
 291 #define L_ISEQU(a, b)   M_ISEQU((a)->l_ui, (a)->l_uf, (b)->l_ui, (b)->l_uf)
 292
 293 /*
 294  * s_fp/double and u_fp/double conversions
 295  */
 296 #define FRIC            65536.                  /* 2^16 as a double */
 297 #define DTOFP(r)        ((s_fp)((r) * FRIC))
 298 #define DTOUFP(r)       ((u_fp)((r) * FRIC))
 299 #define FPTOD(r)        ((double)(r) / FRIC)
 300
 301 /*
 302  * l_fp/double conversions
 303  */
 304 #define FRAC            4294967296.             /* 2^32 as a double */
 305 #define M_DTOLFP(d, r_i, r_uf)                  /* double to l_fp */ \
 306         do { \
 307                 register double d_tmp; \
 308                 \
 309                 d_tmp = (d); \
 310                 if (d_tmp < 0) { \
 311                         d_tmp = -d_tmp; \
 312                         (r_i) = (int32)(d_tmp); \
 313                         (r_uf) = (u_int32)(((d_tmp) - (double)(r_i)) * FRAC); \
 314                         M_NEG((r_i), (r_uf)); \
 315                 } else { \
 316                         (r_i) = (int32)(d_tmp); \
 317                         (r_uf) = (u_int32)(((d_tmp) - (double)(r_i)) * FRAC); \
 318                 } \
 319         } while (0)
 320 #define M_LFPTOD(r_i, r_uf, d)                  /* l_fp to double */ \
 321         do { \
 322                 register l_fp l_tmp; \
 323                 \
 324                 l_tmp.l_i = (r_i); \
 325                 l_tmp.l_f = (r_uf); \
 326                 if (l_tmp.l_i < 0) { \
 327                         M_NEG(l_tmp.l_i, l_tmp.l_uf); \
 328                         (d) = -((double)l_tmp.l_i + ((double)l_tmp.l_uf) / FRAC); \
 329                 } else { \
 330                         (d) = (double)l_tmp.l_i + ((double)l_tmp.l_uf) / FRAC; \
 331                 } \
 332         } while (0)
 333 #define DTOLFP(d, v)    M_DTOLFP((d), (v)->l_ui, (v)->l_uf)
 334 #define LFPTOD(v, d)    M_LFPTOD((v)->l_ui, (v)->l_uf, (d))
 335
 336 /*
 337  * Prototypes
 338  */
 339 extern  char *  dofptoa         (u_fp, int, short, int);
 340 extern  char *  dolfptoa        (u_long, u_long, int, short, int);
 341
 342 extern  int     atolfp          (const char *, l_fp *);
 343 extern  int     buftvtots       (const char *, l_fp *);
 344 extern  char *  fptoa           (s_fp, short);
 345 extern  char *  fptoms          (s_fp, short);
 346 extern  int     hextolfp        (const char *, l_fp *);
 347 extern  void    gpstolfp        (int, int, unsigned long, l_fp *);
 348 extern  int     mstolfp         (const char *, l_fp *);
 349 extern  char *  prettydate      (l_fp *);
 350 extern  char *  gmprettydate    (l_fp *);
 351 extern  char *  uglydate        (l_fp *);
 352 extern  void    mfp_mul         (int32 *, u_int32 *, int32, u_int32, int32, u_int32);
 353
 354 extern  void    get_systime     (l_fp *);
 355 extern  int     step_systime    (double);
 356 extern  int     adj_systime     (double);
 357
 358 extern  struct tm * ntp2unix_tm (u_long ntp, int local);
 359
 360 #define lfptoa(fpv, ndec)       mfptoa((fpv)->l_ui, (fpv)->l_uf, (ndec))
 361 #define lfptoms(fpv, ndec)      mfptoms((fpv)->l_ui, (fpv)->l_uf, (ndec))
 362
 363 #define stoa(addr)              socktoa(addr)
 364 #define ntoa(addr)              stoa(addr)
 365 #define stohost(addr)           socktohost(addr)
 366
 367 #define ufptoa(fpv, ndec)       dofptoa((fpv), 0, (ndec), 0)
 368 #define ufptoms(fpv, ndec)      dofptoa((fpv), 0, (ndec), 1)
 369 #define ulfptoa(fpv, ndec)      dolfptoa((fpv)->l_ui, (fpv)->l_uf, 0, (ndec), 0)
 370 #define ulfptoms(fpv, ndec)     dolfptoa((fpv)->l_ui, (fpv)->l_uf, 0, (ndec), 1)
 371 #define umfptoa(fpi, fpf, ndec) dolfptoa((fpi), (fpf), 0, (ndec), 0)
 372
 373 #endif /* NTP_FP_H */