xref: /netbsd-src/lib/libc/rpc/xdr_float.c (revision 2a399c6883d870daece976daec6ffa7bb7f934ce)
1 /*	$NetBSD: xdr_float.c,v 1.13 1997/07/21 14:08:44 jtc Exp $	*/
2 
3 /*
4  * Sun RPC is a product of Sun Microsystems, Inc. and is provided for
5  * unrestricted use provided that this legend is included on all tape
6  * media and as a part of the software program in whole or part.  Users
7  * may copy or modify Sun RPC without charge, but are not authorized
8  * to license or distribute it to anyone else except as part of a product or
9  * program developed by the user.
10  *
11  * SUN RPC IS PROVIDED AS IS WITH NO WARRANTIES OF ANY KIND INCLUDING THE
12  * WARRANTIES OF DESIGN, MERCHANTIBILITY AND FITNESS FOR A PARTICULAR
13  * PURPOSE, OR ARISING FROM A COURSE OF DEALING, USAGE OR TRADE PRACTICE.
14  *
15  * Sun RPC is provided with no support and without any obligation on the
16  * part of Sun Microsystems, Inc. to assist in its use, correction,
17  * modification or enhancement.
18  *
19  * SUN MICROSYSTEMS, INC. SHALL HAVE NO LIABILITY WITH RESPECT TO THE
20  * INFRINGEMENT OF COPYRIGHTS, TRADE SECRETS OR ANY PATENTS BY SUN RPC
21  * OR ANY PART THEREOF.
22  *
23  * In no event will Sun Microsystems, Inc. be liable for any lost revenue
24  * or profits or other special, indirect and consequential damages, even if
25  * Sun has been advised of the possibility of such damages.
26  *
27  * Sun Microsystems, Inc.
28  * 2550 Garcia Avenue
29  * Mountain View, California  94043
30  */
31 
32 #include <sys/cdefs.h>
33 #if defined(LIBC_SCCS) && !defined(lint)
34 #if 0
35 static char *sccsid = "@(#)xdr_float.c 1.12 87/08/11 Copyr 1984 Sun Micro";
36 static char *sccsid = "@(#)xdr_float.c	2.1 88/07/29 4.0 RPCSRC";
37 #else
38 __RCSID("$NetBSD: xdr_float.c,v 1.13 1997/07/21 14:08:44 jtc Exp $");
39 #endif
40 #endif
41 
42 /*
43  * xdr_float.c, Generic XDR routines impelmentation.
44  *
45  * Copyright (C) 1984, Sun Microsystems, Inc.
46  *
47  * These are the "floating point" xdr routines used to (de)serialize
48  * most common data items.  See xdr.h for more info on the interface to
49  * xdr.
50  */
51 
52 #include "namespace.h"
53 #include <stdio.h>
54 #include <sys/types.h>
55 #include <sys/param.h>
56 #include <rpc/types.h>
57 #include <rpc/xdr.h>
58 
59 #ifdef __weak_alias
60 __weak_alias(xdr_double,_xdr_double);
61 __weak_alias(xdr_float,_xdr_float);
62 #endif
63 
64 /*
65  * NB: Not portable.
66  * This routine works on machines with IEEE754 FP and Vaxen.
67  */
68 
69 #if defined(__m68k__) || defined(__sparc__) || defined(__i386__) || \
70     defined(__mips__) || defined(__ns32k__) || defined(__alpha__) || \
71     defined(__arm32__) || defined(__powerpc__)
72 #include <machine/endian.h>
73 #define IEEEFP
74 #endif
75 
76 #ifdef vax
77 
78 /* What IEEE single precision floating point looks like on a Vax */
79 struct	ieee_single {
80 	unsigned int	mantissa: 23;
81 	unsigned int	exp     : 8;
82 	unsigned int	sign    : 1;
83 };
84 
85 /* Vax single precision floating point */
86 struct	vax_single {
87 	unsigned int	mantissa1 : 7;
88 	unsigned int	exp       : 8;
89 	unsigned int	sign      : 1;
90 	unsigned int	mantissa2 : 16;
91 };
92 
93 #define VAX_SNG_BIAS	0x81
94 #define IEEE_SNG_BIAS	0x7f
95 
96 static struct sgl_limits {
97 	struct vax_single s;
98 	struct ieee_single ieee;
99 } sgl_limits[2] = {
100 	{{ 0x7f, 0xff, 0x0, 0xffff },	/* Max Vax */
101 	{ 0x0, 0xff, 0x0 }},		/* Max IEEE */
102 	{{ 0x0, 0x0, 0x0, 0x0 },	/* Min Vax */
103 	{ 0x0, 0x0, 0x0 }}		/* Min IEEE */
104 };
105 #endif /* vax */
106 
107 bool_t
108 xdr_float(xdrs, fp)
109 	register XDR *xdrs;
110 	register float *fp;
111 {
112 #ifdef IEEEFP
113 	bool_t rv;
114 	long tmpl;
115 #else
116 	struct ieee_single is;
117 	struct vax_single vs, *vsp;
118 	struct sgl_limits *lim;
119 	int i;
120 #endif
121 	switch (xdrs->x_op) {
122 
123 	case XDR_ENCODE:
124 #ifdef IEEEFP
125 		tmpl = *(int32_t *)fp;
126 		return (XDR_PUTLONG(xdrs, &tmpl));
127 #else
128 		vs = *((struct vax_single *)fp);
129 		for (i = 0, lim = sgl_limits;
130 			i < sizeof(sgl_limits)/sizeof(struct sgl_limits);
131 			i++, lim++) {
132 			if ((vs.mantissa2 == lim->s.mantissa2) &&
133 				(vs.exp == lim->s.exp) &&
134 				(vs.mantissa1 == lim->s.mantissa1)) {
135 				is = lim->ieee;
136 				goto shipit;
137 			}
138 		}
139 		is.exp = vs.exp - VAX_SNG_BIAS + IEEE_SNG_BIAS;
140 		is.mantissa = (vs.mantissa1 << 16) | vs.mantissa2;
141 	shipit:
142 		is.sign = vs.sign;
143 		return (XDR_PUTLONG(xdrs, (long *)&is));
144 #endif
145 
146 	case XDR_DECODE:
147 #ifdef IEEEFP
148 		rv = XDR_GETLONG(xdrs, &tmpl);
149 		*(int32_t *)fp = tmpl;
150 		return (rv);
151 #else
152 		vsp = (struct vax_single *)fp;
153 		if (!XDR_GETLONG(xdrs, (long *)&is))
154 			return (FALSE);
155 		for (i = 0, lim = sgl_limits;
156 			i < sizeof(sgl_limits)/sizeof(struct sgl_limits);
157 			i++, lim++) {
158 			if ((is.exp == lim->ieee.exp) &&
159 				(is.mantissa == lim->ieee.mantissa)) {
160 				*vsp = lim->s;
161 				goto doneit;
162 			}
163 		}
164 		vsp->exp = is.exp - IEEE_SNG_BIAS + VAX_SNG_BIAS;
165 		vsp->mantissa2 = is.mantissa;
166 		vsp->mantissa1 = (is.mantissa >> 16);
167 	doneit:
168 		vsp->sign = is.sign;
169 		return (TRUE);
170 #endif
171 
172 	case XDR_FREE:
173 		return (TRUE);
174 	}
175 	return (FALSE);
176 }
177 
178 #ifdef vax
179 /* What IEEE double precision floating point looks like on a Vax */
180 struct	ieee_double {
181 	unsigned int	mantissa1 : 20;
182 	unsigned int	exp       : 11;
183 	unsigned int	sign      : 1;
184 	unsigned int	mantissa2 : 32;
185 };
186 
187 /* Vax double precision floating point */
188 struct  vax_double {
189 	unsigned int	mantissa1 : 7;
190 	unsigned int	exp       : 8;
191 	unsigned int	sign      : 1;
192 	unsigned int	mantissa2 : 16;
193 	unsigned int	mantissa3 : 16;
194 	unsigned int	mantissa4 : 16;
195 };
196 
197 #define VAX_DBL_BIAS	0x81
198 #define IEEE_DBL_BIAS	0x3ff
199 #define MASK(nbits)	((1 << nbits) - 1)
200 
201 static struct dbl_limits {
202 	struct	vax_double d;
203 	struct	ieee_double ieee;
204 } dbl_limits[2] = {
205 	{{ 0x7f, 0xff, 0x0, 0xffff, 0xffff, 0xffff },	/* Max Vax */
206 	{ 0x0, 0x7ff, 0x0, 0x0 }},			/* Max IEEE */
207 	{{ 0x0, 0x0, 0x0, 0x0, 0x0, 0x0},		/* Min Vax */
208 	{ 0x0, 0x0, 0x0, 0x0 }}				/* Min IEEE */
209 };
210 
211 #endif /* vax */
212 
213 
214 bool_t
215 xdr_double(xdrs, dp)
216 	register XDR *xdrs;
217 	double *dp;
218 {
219 #ifdef IEEEFP
220 	register int32_t *i32p;
221 	bool_t rv;
222 	long tmpl;
223 #else
224 	register long *lp;
225 	struct	ieee_double id;
226 	struct	vax_double vd;
227 	register struct dbl_limits *lim;
228 	int i;
229 #endif
230 
231 	switch (xdrs->x_op) {
232 
233 	case XDR_ENCODE:
234 #ifdef IEEEFP
235 		i32p = (int32_t *)dp;
236 #if BYTE_ORDER == BIG_ENDIAN
237 		tmpl = *i32p++;
238 		rv = XDR_PUTLONG(xdrs, &tmpl);
239 		if (!rv)
240 			return (rv);
241 		tmpl = *i32p;
242 		rv = XDR_PUTLONG(xdrs, &tmpl);
243 #else
244 		tmpl = *(i32p+1);
245 		rv = XDR_PUTLONG(xdrs, &tmpl);
246 		if (!rv)
247 			return (rv);
248 		tmpl = *i32p;
249 		rv = XDR_PUTLONG(xdrs, &tmpl);
250 #endif
251 		return (rv);
252 #else
253 		vd = *((struct vax_double *)dp);
254 		for (i = 0, lim = dbl_limits;
255 			i < sizeof(dbl_limits)/sizeof(struct dbl_limits);
256 			i++, lim++) {
257 			if ((vd.mantissa4 == lim->d.mantissa4) &&
258 				(vd.mantissa3 == lim->d.mantissa3) &&
259 				(vd.mantissa2 == lim->d.mantissa2) &&
260 				(vd.mantissa1 == lim->d.mantissa1) &&
261 				(vd.exp == lim->d.exp)) {
262 				id = lim->ieee;
263 				goto shipit;
264 			}
265 		}
266 		id.exp = vd.exp - VAX_DBL_BIAS + IEEE_DBL_BIAS;
267 		id.mantissa1 = (vd.mantissa1 << 13) | (vd.mantissa2 >> 3);
268 		id.mantissa2 = ((vd.mantissa2 & MASK(3)) << 29) |
269 				(vd.mantissa3 << 13) |
270 				((vd.mantissa4 >> 3) & MASK(13));
271 	shipit:
272 		id.sign = vd.sign;
273 		lp = (long *)&id;
274 		return (XDR_PUTLONG(xdrs, lp++) && XDR_PUTLONG(xdrs, lp));
275 #endif
276 
277 	case XDR_DECODE:
278 #ifdef IEEEFP
279 		i32p = (int32_t *)dp;
280 #if BYTE_ORDER == BIG_ENDIAN
281 		rv = XDR_GETLONG(xdrs, &tmpl);
282 		*i32p++ = tmpl;
283 		if (!rv)
284 			return (rv);
285 		rv = XDR_GETLONG(xdrs, &tmpl);
286 		*i32p = tmpl;
287 #else
288 		rv = XDR_GETLONG(xdrs, &tmpl);
289 		*(i32p+1) = tmpl;
290 		if (!rv)
291 			return (rv);
292 		rv = XDR_GETLONG(xdrs, &tmpl);
293 		*i32p = tmpl;
294 #endif
295 		return (rv);
296 #else
297 		lp = (long *)&id;
298 		if (!XDR_GETLONG(xdrs, lp++) || !XDR_GETLONG(xdrs, lp))
299 			return (FALSE);
300 		for (i = 0, lim = dbl_limits;
301 			i < sizeof(dbl_limits)/sizeof(struct dbl_limits);
302 			i++, lim++) {
303 			if ((id.mantissa2 == lim->ieee.mantissa2) &&
304 				(id.mantissa1 == lim->ieee.mantissa1) &&
305 				(id.exp == lim->ieee.exp)) {
306 				vd = lim->d;
307 				goto doneit;
308 			}
309 		}
310 		vd.exp = id.exp - IEEE_DBL_BIAS + VAX_DBL_BIAS;
311 		vd.mantissa1 = (id.mantissa1 >> 13);
312 		vd.mantissa2 = ((id.mantissa1 & MASK(13)) << 3) |
313 				(id.mantissa2 >> 29);
314 		vd.mantissa3 = (id.mantissa2 >> 13);
315 		vd.mantissa4 = (id.mantissa2 << 3);
316 	doneit:
317 		vd.sign = id.sign;
318 		*dp = *((double *)&vd);
319 		return (TRUE);
320 #endif
321 
322 	case XDR_FREE:
323 		return (TRUE);
324 	}
325 	return (FALSE);
326 }
327