2 * ntp_fp.h - definitions for NTP fixed/floating-point arithmetic
9 #include <sys/socket.h>
10 #include <netinet/in.h>
12 #include "ntp_rfc2553.h"
14 #include "ntp_types.h"
17 * NTP uses two fixed point formats. The first (l_fp) is the "long"
18 * format and is 64 bits long with the decimal between bits 31 and 32.
19 * This is used for time stamps in the NTP packet header (in network
20 * byte order) and for internal computations of offsets (in local host
21 * byte order). We use the same structure for both signed and unsigned
22 * values, which is a big hack but saves rewriting all the operators
23 * twice. Just to confuse this, we also sometimes just carry the
24 * fractional part in calculations, in both signed and unsigned forms.
25 * Anyway, an l_fp looks like:
28 * 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
29 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
31 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
33 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
47 #define l_ui Ul_i.Xl_ui /* unsigned integral part */
48 #define l_i Ul_i.Xl_i /* signed integral part */
49 #define l_uf Ul_f.Xl_uf /* unsigned fractional part */
50 #define l_f Ul_f.Xl_f /* signed fractional part */
53 * Fractional precision (of an l_fp) is actually the number of
56 #define FRACTION_PREC (32)
60 * The second fixed point format is 32 bits, with the decimal between
61 * bits 15 and 16. There is a signed version (s_fp) and an unsigned
62 * version (u_fp). This is used to represent synchronizing distance
63 * and synchronizing dispersion in the NTP packet header (again, in
64 * network byte order) and internally to hold both distance and
65 * dispersion values (in local byte order). In network byte order
69 * 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
70 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
71 * | Integer Part | Fraction Part |
72 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
79 * A unit second in fp format. Actually 2**(half_the_bits_in_a_long)
81 #define FP_SECOND (0x10000)
84 * Byte order conversions
86 #define HTONS_FP(x) (htonl(x))
87 #define HTONL_FP(h, n) do { (n)->l_ui = htonl((h)->l_ui); \
88 (n)->l_uf = htonl((h)->l_uf); } while (0)
89 #define NTOHS_FP(x) (ntohl(x))
90 #define NTOHL_FP(n, h) do { (h)->l_ui = ntohl((n)->l_ui); \
91 (h)->l_uf = ntohl((n)->l_uf); } while (0)
92 #define NTOHL_MFP(ni, nf, hi, hf) \
93 do { (hi) = ntohl(ni); (hf) = ntohl(nf); } while (0)
94 #define HTONL_MFP(hi, hf, ni, nf) \
95 do { (ni) = ntohl(hi); (nf) = ntohl(hf); } while (0)
97 /* funny ones. Converts ts fractions to net order ts */
98 #define HTONL_UF(uf, nts) \
99 do { (nts)->l_ui = 0; (nts)->l_uf = htonl(uf); } while (0)
100 #define HTONL_F(f, nts) do { (nts)->l_uf = htonl(f); \
101 if ((f) & 0x80000000) \
108 * Conversions between the two fixed point types
110 #define MFPTOFP(x_i, x_f) (((x_i) >= 0x00010000) ? 0x7fffffff : \
111 (((x_i) <= -0x00010000) ? 0x80000000 : \
112 (((x_i)<<16) | (((x_f)>>16)&0xffff))))
113 #define LFPTOFP(v) MFPTOFP((v)->l_i, (v)->l_f)
115 #define UFPTOLFP(x, v) ((v)->l_ui = (u_fp)(x)>>16, (v)->l_uf = (x)<<16)
116 #define FPTOLFP(x, v) (UFPTOLFP((x), (v)), (x) < 0 ? (v)->l_ui -= 0x10000 : 0)
118 #define MAXLFP(v) ((v)->l_ui = 0x7fffffff, (v)->l_uf = 0xffffffff)
119 #define MINLFP(v) ((v)->l_ui = 0x80000000, (v)->l_uf = 0)
122 * Primitive operations on long fixed point values. If these are
123 * reminiscent of assembler op codes it's only because some may
124 * be replaced by inline assembler for particular machines someday.
125 * These are the (kind of inefficient) run-anywhere versions.
127 #define M_NEG(v_i, v_f) /* v = -v */ \
130 (v_i) = -((s_fp)(v_i)); \
132 (v_f) = -((s_fp)(v_f)); \
137 #define M_NEGM(r_i, r_f, a_i, a_f) /* r = -a */ \
148 #define M_ADD(r_i, r_f, a_i, a_f) /* r += a */ \
150 register u_int32 lo_tmp; \
151 register u_int32 hi_tmp; \
153 lo_tmp = ((r_f) & 0xffff) + ((a_f) & 0xffff); \
154 hi_tmp = (((r_f) >> 16) & 0xffff) + (((a_f) >> 16) & 0xffff); \
155 if (lo_tmp & 0x10000) \
157 (r_f) = ((hi_tmp & 0xffff) << 16) | (lo_tmp & 0xffff); \
160 if (hi_tmp & 0x10000) \
164 #define M_ADD3(r_ovr, r_i, r_f, a_ovr, a_i, a_f) /* r += a, three word */ \
166 register u_int32 lo_tmp; \
167 register u_int32 hi_tmp; \
169 lo_tmp = ((r_f) & 0xffff) + ((a_f) & 0xffff); \
170 hi_tmp = (((r_f) >> 16) & 0xffff) + (((a_f) >> 16) & 0xffff); \
171 if (lo_tmp & 0x10000) \
173 (r_f) = ((hi_tmp & 0xffff) << 16) | (lo_tmp & 0xffff); \
175 lo_tmp = ((r_i) & 0xffff) + ((a_i) & 0xffff); \
176 if (hi_tmp & 0x10000) \
178 hi_tmp = (((r_i) >> 16) & 0xffff) + (((a_i) >> 16) & 0xffff); \
179 if (lo_tmp & 0x10000) \
181 (r_i) = ((hi_tmp & 0xffff) << 16) | (lo_tmp & 0xffff); \
183 (r_ovr) += (a_ovr); \
184 if (hi_tmp & 0x10000) \
188 #define M_SUB(r_i, r_f, a_i, a_f) /* r -= a */ \
190 register u_int32 lo_tmp; \
191 register u_int32 hi_tmp; \
196 lo_tmp = ((r_f) & 0xffff) + ((-((s_fp)(a_f))) & 0xffff); \
197 hi_tmp = (((r_f) >> 16) & 0xffff) \
198 + (((-((s_fp)(a_f))) >> 16) & 0xffff); \
199 if (lo_tmp & 0x10000) \
201 (r_f) = ((hi_tmp & 0xffff) << 16) | (lo_tmp & 0xffff); \
204 if (hi_tmp & 0x10000) \
209 #define M_RSHIFTU(v_i, v_f) /* v >>= 1, v is unsigned */ \
211 (v_f) = (u_int32)(v_f) >> 1; \
213 (v_f) |= 0x80000000; \
214 (v_i) = (u_int32)(v_i) >> 1; \
217 #define M_RSHIFT(v_i, v_f) /* v >>= 1, v is signed */ \
219 (v_f) = (u_int32)(v_f) >> 1; \
221 (v_f) |= 0x80000000; \
222 if ((v_i) & 0x80000000) \
223 (v_i) = ((v_i) >> 1) | 0x80000000; \
225 (v_i) = (v_i) >> 1; \
228 #define M_LSHIFT(v_i, v_f) /* v <<= 1 */ \
231 if ((v_f) & 0x80000000) \
236 #define M_LSHIFT3(v_ovr, v_i, v_f) /* v <<= 1, with overflow */ \
239 if ((v_i) & 0x80000000) \
242 if ((v_f) & 0x80000000) \
247 #define M_ADDUF(r_i, r_f, uf) /* r += uf, uf is u_int32 fraction */ \
248 M_ADD((r_i), (r_f), 0, (uf)) /* let optimizer worry about it */
250 #define M_SUBUF(r_i, r_f, uf) /* r -= uf, uf is u_int32 fraction */ \
251 M_SUB((r_i), (r_f), 0, (uf)) /* let optimizer worry about it */
253 #define M_ADDF(r_i, r_f, f) /* r += f, f is a int32 fraction */ \
256 M_ADD((r_i), (r_f), 0, (f)); \
258 M_ADD((r_i), (r_f), (-1), (f));\
261 #define M_ISNEG(v_i, v_f) /* v < 0 */ \
262 (((v_i) & 0x80000000) != 0)
264 #define M_ISHIS(a_i, a_f, b_i, b_f) /* a >= b unsigned */ \
265 (((u_int32)(a_i)) > ((u_int32)(b_i)) || \
266 ((a_i) == (b_i) && ((u_int32)(a_f)) >= ((u_int32)(b_f))))
268 #define M_ISGEQ(a_i, a_f, b_i, b_f) /* a >= b signed */ \
269 (((int32)(a_i)) > ((int32)(b_i)) || \
270 ((a_i) == (b_i) && ((u_int32)(a_f)) >= ((u_int32)(b_f))))
272 #define M_ISEQU(a_i, a_f, b_i, b_f) /* a == b unsigned */ \
273 ((a_i) == (b_i) && (a_f) == (b_f))
276 * Operations on the long fp format
278 #define L_ADD(r, a) M_ADD((r)->l_ui, (r)->l_uf, (a)->l_ui, (a)->l_uf)
279 #define L_SUB(r, a) M_SUB((r)->l_ui, (r)->l_uf, (a)->l_ui, (a)->l_uf)
280 #define L_NEG(v) M_NEG((v)->l_ui, (v)->l_uf)
281 #define L_ADDUF(r, uf) M_ADDUF((r)->l_ui, (r)->l_uf, (uf))
282 #define L_SUBUF(r, uf) M_SUBUF((r)->l_ui, (r)->l_uf, (uf))
283 #define L_ADDF(r, f) M_ADDF((r)->l_ui, (r)->l_uf, (f))
284 #define L_RSHIFT(v) M_RSHIFT((v)->l_i, (v)->l_uf)
285 #define L_RSHIFTU(v) M_RSHIFTU((v)->l_ui, (v)->l_uf)
286 #define L_LSHIFT(v) M_LSHIFT((v)->l_ui, (v)->l_uf)
287 #define L_CLR(v) ((v)->l_ui = (v)->l_uf = 0)
289 #define L_ISNEG(v) (((v)->l_ui & 0x80000000) != 0)
290 #define L_ISZERO(v) ((v)->l_ui == 0 && (v)->l_uf == 0)
291 #define L_ISHIS(a, b) ((a)->l_ui > (b)->l_ui || \
292 ((a)->l_ui == (b)->l_ui && (a)->l_uf >= (b)->l_uf))
293 #define L_ISGEQ(a, b) ((a)->l_i > (b)->l_i || \
294 ((a)->l_i == (b)->l_i && (a)->l_uf >= (b)->l_uf))
295 #define L_ISEQU(a, b) M_ISEQU((a)->l_ui, (a)->l_uf, (b)->l_ui, (b)->l_uf)
298 * s_fp/double and u_fp/double conversions
300 #define FRIC 65536. /* 2^16 as a double */
301 #define DTOFP(r) ((s_fp)((r) * FRIC))
302 #define DTOUFP(r) ((u_fp)((r) * FRIC))
303 #define FPTOD(r) ((double)(r) / FRIC)
306 * l_fp/double conversions
308 #define FRAC 4294967296. /* 2^32 as a double */
309 #define M_DTOLFP(d, r_i, r_uf) /* double to l_fp */ \
311 register double d_tmp; \
316 (r_i) = (int32)(d_tmp); \
317 (r_uf) = (u_int32)(((d_tmp) - (double)(r_i)) * FRAC); \
318 M_NEG((r_i), (r_uf)); \
320 (r_i) = (int32)(d_tmp); \
321 (r_uf) = (u_int32)(((d_tmp) - (double)(r_i)) * FRAC); \
324 #define M_LFPTOD(r_i, r_uf, d) /* l_fp to double */ \
326 register l_fp l_tmp; \
329 l_tmp.l_f = (r_uf); \
330 if (l_tmp.l_i < 0) { \
331 M_NEG(l_tmp.l_i, l_tmp.l_uf); \
332 (d) = -((double)l_tmp.l_i + ((double)l_tmp.l_uf) / FRAC); \
334 (d) = (double)l_tmp.l_i + ((double)l_tmp.l_uf) / FRAC; \
337 #define DTOLFP(d, v) M_DTOLFP((d), (v)->l_ui, (v)->l_uf)
338 #define LFPTOD(v, d) M_LFPTOD((v)->l_ui, (v)->l_uf, (d))
343 extern char * dofptoa P((u_fp, int, short, int));
344 extern char * dolfptoa P((u_long, u_long, int, short, int));
346 extern int atolfp P((const char *, l_fp *));
347 extern int buftvtots P((const char *, l_fp *));
348 extern char * fptoa P((s_fp, short));
349 extern char * fptoms P((s_fp, short));
350 extern int hextolfp P((const char *, l_fp *));
351 extern void gpstolfp P((int, int, unsigned long, l_fp *));
352 extern int mstolfp P((const char *, l_fp *));
353 extern char * prettydate P((l_fp *));
354 extern char * gmprettydate P((l_fp *));
355 extern char * uglydate P((l_fp *));
356 extern void mfp_mul P((int32 *, u_int32 *, int32, u_int32, int32, u_int32));
358 extern void get_systime P((l_fp *));
359 extern int step_systime P((double));
360 extern int adj_systime P((double));
362 extern struct tm * ntp2unix_tm P((u_long ntp, int local));
364 #define lfptoa(_fpv, _ndec) mfptoa((_fpv)->l_ui, (_fpv)->l_uf, (_ndec))
365 #define lfptoms(_fpv, _ndec) mfptoms((_fpv)->l_ui, (_fpv)->l_uf, (_ndec))
367 #define stoa(_sin) socktoa((_sin))
368 #define stohost(_sin) socktohost((_sin))
370 #define ntoa(_sin) stoa(_sin)
371 #define ntohost(_sin) stohost(_sin)
373 #define ufptoa(_fpv, _ndec) dofptoa((_fpv), 0, (_ndec), 0)
374 #define ufptoms(_fpv, _ndec) dofptoa((_fpv), 0, (_ndec), 1)
375 #define ulfptoa(_fpv, _ndec) dolfptoa((_fpv)->l_ui, (_fpv)->l_uf, 0, (_ndec), 0)
376 #define ulfptoms(_fpv, _ndec) dolfptoa((_fpv)->l_ui, (_fpv)->l_uf, 0, (_ndec), 1)
377 #define umfptoa(_fpi, _fpf, _ndec) dolfptoa((_fpi), (_fpf), 0, (_ndec), 0)
379 #endif /* NTP_FP_H */