xref: /original-bsd/lib/librpc/rpc/xdr_float.c (revision 3839ed90)
1 /* @(#)xdr_float.c	2.1 88/07/29 4.0 RPCSRC */
2 /*
3  * Sun RPC is a product of Sun Microsystems, Inc. and is provided for
4  * unrestricted use provided that this legend is included on all tape
5  * media and as a part of the software program in whole or part.  Users
6  * may copy or modify Sun RPC without charge, but are not authorized
7  * to license or distribute it to anyone else except as part of a product or
8  * program developed by the user.
9  *
10  * SUN RPC IS PROVIDED AS IS WITH NO WARRANTIES OF ANY KIND INCLUDING THE
11  * WARRANTIES OF DESIGN, MERCHANTIBILITY AND FITNESS FOR A PARTICULAR
12  * PURPOSE, OR ARISING FROM A COURSE OF DEALING, USAGE OR TRADE PRACTICE.
13  *
14  * Sun RPC is provided with no support and without any obligation on the
15  * part of Sun Microsystems, Inc. to assist in its use, correction,
16  * modification or enhancement.
17  *
18  * SUN MICROSYSTEMS, INC. SHALL HAVE NO LIABILITY WITH RESPECT TO THE
19  * INFRINGEMENT OF COPYRIGHTS, TRADE SECRETS OR ANY PATENTS BY SUN RPC
20  * OR ANY PART THEREOF.
21  *
22  * In no event will Sun Microsystems, Inc. be liable for any lost revenue
23  * or profits or other special, indirect and consequential damages, even if
24  * Sun has been advised of the possibility of such damages.
25  *
26  * Sun Microsystems, Inc.
27  * 2550 Garcia Avenue
28  * Mountain View, California  94043
29  */
30 #if !defined(lint) && defined(SCCSIDS)
31 static char sccsid[] = "@(#)xdr_float.c 1.12 87/08/11 Copyr 1984 Sun Micro";
32 #endif
33 
34 /*
35  * xdr_float.c, Generic XDR routines impelmentation.
36  *
37  * Copyright (C) 1984, Sun Microsystems, Inc.
38  *
39  * These are the "floating point" xdr routines used to (de)serialize
40  * most common data items.  See xdr.h for more info on the interface to
41  * xdr.
42  */
43 
44 #include <stdio.h>
45 
46 #include <rpc/types.h>
47 #include <rpc/xdr.h>
48 
49 /*
50  * NB: Not portable.
51  * This routine works on Suns (Sky / 68000's) and Vaxen.
52  */
53 
54 #ifdef vax
55 
56 /* What IEEE single precision floating point looks like on a Vax */
57 struct	ieee_single {
58 	unsigned int	mantissa: 23;
59 	unsigned int	exp     : 8;
60 	unsigned int	sign    : 1;
61 };
62 
63 /* Vax single precision floating point */
64 struct	vax_single {
65 	unsigned int	mantissa1 : 7;
66 	unsigned int	exp       : 8;
67 	unsigned int	sign      : 1;
68 	unsigned int	mantissa2 : 16;
69 };
70 
71 #define VAX_SNG_BIAS	0x81
72 #define IEEE_SNG_BIAS	0x7f
73 
74 static struct sgl_limits {
75 	struct vax_single s;
76 	struct ieee_single ieee;
77 } sgl_limits[2] = {
78 	{{ 0x7f, 0xff, 0x0, 0xffff },	/* Max Vax */
79 	{ 0x0, 0xff, 0x0 }},		/* Max IEEE */
80 	{{ 0x0, 0x0, 0x0, 0x0 },	/* Min Vax */
81 	{ 0x0, 0x0, 0x0 }}		/* Min IEEE */
82 };
83 #endif /* vax */
84 
85 bool_t
86 xdr_float(xdrs, fp)
87 	register XDR *xdrs;
88 	register float *fp;
89 {
90 #if !defined(mc68000) && !defined(sparc)
91 	struct ieee_single is;
92 	struct vax_single vs, *vsp;
93 	struct sgl_limits *lim;
94 	int i;
95 #endif
96 	switch (xdrs->x_op) {
97 
98 	case XDR_ENCODE:
99 #if defined(mc68000) || defined(sparc)
100 		return (XDR_PUTLONG(xdrs, (long *)fp));
101 #else
102 		vs = *((struct vax_single *)fp);
103 		for (i = 0, lim = sgl_limits;
104 			i < sizeof(sgl_limits)/sizeof(struct sgl_limits);
105 			i++, lim++) {
106 			if ((vs.mantissa2 == lim->s.mantissa2) &&
107 				(vs.exp == lim->s.exp) &&
108 				(vs.mantissa1 == lim->s.mantissa1)) {
109 				is = lim->ieee;
110 				goto shipit;
111 			}
112 		}
113 		is.exp = vs.exp - VAX_SNG_BIAS + IEEE_SNG_BIAS;
114 		is.mantissa = (vs.mantissa1 << 16) | vs.mantissa2;
115 	shipit:
116 		is.sign = vs.sign;
117 		return (XDR_PUTLONG(xdrs, (long *)&is));
118 #endif
119 
120 	case XDR_DECODE:
121 #if defined(mc68000) || defined(sparc)
122 		return (XDR_GETLONG(xdrs, (long *)fp));
123 #else
124 		vsp = (struct vax_single *)fp;
125 		if (!XDR_GETLONG(xdrs, (long *)&is))
126 			return (FALSE);
127 		for (i = 0, lim = sgl_limits;
128 			i < sizeof(sgl_limits)/sizeof(struct sgl_limits);
129 			i++, lim++) {
130 			if ((is.exp == lim->ieee.exp) &&
131 				(is.mantissa == lim->ieee.mantissa)) {
132 				*vsp = lim->s;
133 				goto doneit;
134 			}
135 		}
136 		vsp->exp = is.exp - IEEE_SNG_BIAS + VAX_SNG_BIAS;
137 		vsp->mantissa2 = is.mantissa;
138 		vsp->mantissa1 = (is.mantissa >> 16);
139 	doneit:
140 		vsp->sign = is.sign;
141 		return (TRUE);
142 #endif
143 
144 	case XDR_FREE:
145 		return (TRUE);
146 	}
147 	return (FALSE);
148 }
149 
150 /*
151  * This routine works on Suns (Sky / 68000's) and Vaxen.
152  */
153 
154 #ifdef vax
155 /* What IEEE double precision floating point looks like on a Vax */
156 struct	ieee_double {
157 	unsigned int	mantissa1 : 20;
158 	unsigned int	exp       : 11;
159 	unsigned int	sign      : 1;
160 	unsigned int	mantissa2 : 32;
161 };
162 
163 /* Vax double precision floating point */
164 struct  vax_double {
165 	unsigned int	mantissa1 : 7;
166 	unsigned int	exp       : 8;
167 	unsigned int	sign      : 1;
168 	unsigned int	mantissa2 : 16;
169 	unsigned int	mantissa3 : 16;
170 	unsigned int	mantissa4 : 16;
171 };
172 
173 #define VAX_DBL_BIAS	0x81
174 #define IEEE_DBL_BIAS	0x3ff
175 #define MASK(nbits)	((1 << nbits) - 1)
176 
177 static struct dbl_limits {
178 	struct	vax_double d;
179 	struct	ieee_double ieee;
180 } dbl_limits[2] = {
181 	{{ 0x7f, 0xff, 0x0, 0xffff, 0xffff, 0xffff },	/* Max Vax */
182 	{ 0x0, 0x7ff, 0x0, 0x0 }},			/* Max IEEE */
183 	{{ 0x0, 0x0, 0x0, 0x0, 0x0, 0x0},		/* Min Vax */
184 	{ 0x0, 0x0, 0x0, 0x0 }}				/* Min IEEE */
185 };
186 
187 #endif /* vax */
188 
189 
190 bool_t
191 xdr_double(xdrs, dp)
192 	register XDR *xdrs;
193 	double *dp;
194 {
195 	register long *lp;
196 #if !defined(mc68000) && !defined(sparc)
197 	struct	ieee_double id;
198 	struct	vax_double vd;
199 	register struct dbl_limits *lim;
200 	int i;
201 #endif
202 
203 	switch (xdrs->x_op) {
204 
205 	case XDR_ENCODE:
206 #if defined(mc68000) || defined(sparc)
207 		lp = (long *)dp;
208 #else
209 		vd = *((struct vax_double *)dp);
210 		for (i = 0, lim = dbl_limits;
211 			i < sizeof(dbl_limits)/sizeof(struct dbl_limits);
212 			i++, lim++) {
213 			if ((vd.mantissa4 == lim->d.mantissa4) &&
214 				(vd.mantissa3 == lim->d.mantissa3) &&
215 				(vd.mantissa2 == lim->d.mantissa2) &&
216 				(vd.mantissa1 == lim->d.mantissa1) &&
217 				(vd.exp == lim->d.exp)) {
218 				id = lim->ieee;
219 				goto shipit;
220 			}
221 		}
222 		id.exp = vd.exp - VAX_DBL_BIAS + IEEE_DBL_BIAS;
223 		id.mantissa1 = (vd.mantissa1 << 13) | (vd.mantissa2 >> 3);
224 		id.mantissa2 = ((vd.mantissa2 & MASK(3)) << 29) |
225 				(vd.mantissa3 << 13) |
226 				((vd.mantissa4 >> 3) & MASK(13));
227 	shipit:
228 		id.sign = vd.sign;
229 		lp = (long *)&id;
230 #endif
231 		return (XDR_PUTLONG(xdrs, lp++) && XDR_PUTLONG(xdrs, lp));
232 
233 	case XDR_DECODE:
234 #if defined(mc68000) || defined(sparc)
235 		lp = (long *)dp;
236 		return (XDR_GETLONG(xdrs, lp++) && XDR_GETLONG(xdrs, lp));
237 #else
238 		lp = (long *)&id;
239 		if (!XDR_GETLONG(xdrs, lp++) || !XDR_GETLONG(xdrs, lp))
240 			return (FALSE);
241 		for (i = 0, lim = dbl_limits;
242 			i < sizeof(dbl_limits)/sizeof(struct dbl_limits);
243 			i++, lim++) {
244 			if ((id.mantissa2 == lim->ieee.mantissa2) &&
245 				(id.mantissa1 == lim->ieee.mantissa1) &&
246 				(id.exp == lim->ieee.exp)) {
247 				vd = lim->d;
248 				goto doneit;
249 			}
250 		}
251 		vd.exp = id.exp - IEEE_DBL_BIAS + VAX_DBL_BIAS;
252 		vd.mantissa1 = (id.mantissa1 >> 13);
253 		vd.mantissa2 = ((id.mantissa1 & MASK(13)) << 3) |
254 				(id.mantissa2 >> 29);
255 		vd.mantissa3 = (id.mantissa2 >> 13);
256 		vd.mantissa4 = (id.mantissa2 << 3);
257 	doneit:
258 		vd.sign = id.sign;
259 		*dp = *((double *)&vd);
260 		return (TRUE);
261 #endif
262 
263 	case XDR_FREE:
264 		return (TRUE);
265 	}
266 	return (FALSE);
267 }
268