File:  [ELWIX - Embedded LightWeight unIX -] / embedaddon / ntp / include / ntp_fp.h
Revision 1.1.1.1 (vendor branch): download - view: text, annotated - select for diffs - revision graph
Tue May 29 12:08:38 2012 UTC (12 years, 1 month ago) by misho
Branches: ntp, MAIN
CVS tags: v4_2_6p5p0, v4_2_6p5, HEAD
ntp 4.2.6p5

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

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