xref: /netbsd-src/lib/libc/rpc/xdr_float.c (revision 1325a26d7baccbd782fff4b82bf88dc3b8213d27)
1 /*	$NetBSD: xdr_float.c,v 1.18 1998/11/15 17:32:47 christos 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 1.18 1998/11/15 17:32:47 christos 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 
54 #include <sys/types.h>
55 #include <sys/param.h>
56 
57 #include <stdio.h>
58 
59 #include <rpc/types.h>
60 #include <rpc/xdr.h>
61 
62 #ifdef __weak_alias
63 __weak_alias(xdr_double,_xdr_double);
64 __weak_alias(xdr_float,_xdr_float);
65 #endif
66 
67 /*
68  * NB: Not portable.
69  * This routine works on machines with IEEE754 FP and Vaxen.
70  */
71 
72 #if defined(__m68k__) || defined(__sparc__) || defined(__i386__) || \
73     defined(__mips__) || defined(__ns32k__) || defined(__alpha__) || \
74     defined(__arm32__) || defined(__powerpc__)
75 #include <machine/endian.h>
76 #define IEEEFP
77 #endif
78 
79 #if defined(__vax__)
80 
81 /* What IEEE single precision floating point looks like on a Vax */
82 struct	ieee_single {
83 	unsigned int	mantissa: 23;
84 	unsigned int	exp     : 8;
85 	unsigned int	sign    : 1;
86 };
87 
88 /* Vax single precision floating point */
89 struct	vax_single {
90 	unsigned int	mantissa1 : 7;
91 	unsigned int	exp       : 8;
92 	unsigned int	sign      : 1;
93 	unsigned int	mantissa2 : 16;
94 };
95 
96 #define VAX_SNG_BIAS	0x81
97 #define IEEE_SNG_BIAS	0x7f
98 
99 static struct sgl_limits {
100 	struct vax_single s;
101 	struct ieee_single ieee;
102 } sgl_limits[2] = {
103 	{{ 0x7f, 0xff, 0x0, 0xffff },	/* Max Vax */
104 	{ 0x0, 0xff, 0x0 }},		/* Max IEEE */
105 	{{ 0x0, 0x0, 0x0, 0x0 },	/* Min Vax */
106 	{ 0x0, 0x0, 0x0 }}		/* Min IEEE */
107 };
108 #endif /* vax */
109 
110 bool_t
111 xdr_float(xdrs, fp)
112 	XDR *xdrs;
113 	float *fp;
114 {
115 #ifdef IEEEFP
116 	bool_t rv;
117 	long tmpl;
118 #else
119 	struct ieee_single is;
120 	struct vax_single vs, *vsp;
121 	struct sgl_limits *lim;
122 	int i;
123 #endif
124 	switch (xdrs->x_op) {
125 
126 	case XDR_ENCODE:
127 #ifdef IEEEFP
128 		tmpl = *(int32_t *)(void *)fp;
129 		return (XDR_PUTLONG(xdrs, &tmpl));
130 #else
131 		vs = *((struct vax_single *)fp);
132 		for (i = 0, lim = sgl_limits;
133 			i < sizeof(sgl_limits)/sizeof(struct sgl_limits);
134 			i++, lim++) {
135 			if ((vs.mantissa2 == lim->s.mantissa2) &&
136 				(vs.exp == lim->s.exp) &&
137 				(vs.mantissa1 == lim->s.mantissa1)) {
138 				is = lim->ieee;
139 				goto shipit;
140 			}
141 		}
142 		is.exp = vs.exp - VAX_SNG_BIAS + IEEE_SNG_BIAS;
143 		is.mantissa = (vs.mantissa1 << 16) | vs.mantissa2;
144 	shipit:
145 		is.sign = vs.sign;
146 		return (XDR_PUTLONG(xdrs, (long *)&is));
147 #endif
148 
149 	case XDR_DECODE:
150 #ifdef IEEEFP
151 		rv = XDR_GETLONG(xdrs, &tmpl);
152 		*(int32_t *)(void *)fp = (int32_t)tmpl;
153 		return (rv);
154 #else
155 		vsp = (struct vax_single *)fp;
156 		if (!XDR_GETLONG(xdrs, (long *)&is))
157 			return (FALSE);
158 		for (i = 0, lim = sgl_limits;
159 			i < sizeof(sgl_limits)/sizeof(struct sgl_limits);
160 			i++, lim++) {
161 			if ((is.exp == lim->ieee.exp) &&
162 				(is.mantissa == lim->ieee.mantissa)) {
163 				*vsp = lim->s;
164 				goto doneit;
165 			}
166 		}
167 		vsp->exp = is.exp - IEEE_SNG_BIAS + VAX_SNG_BIAS;
168 		vsp->mantissa2 = is.mantissa;
169 		vsp->mantissa1 = (is.mantissa >> 16);
170 	doneit:
171 		vsp->sign = is.sign;
172 		return (TRUE);
173 #endif
174 
175 	case XDR_FREE:
176 		return (TRUE);
177 	}
178 	/* NOTREACHED */
179 	return (FALSE);
180 }
181 
182 #if defined(__vax__)
183 /* What IEEE double precision floating point looks like on a Vax */
184 struct	ieee_double {
185 	unsigned int	mantissa1 : 20;
186 	unsigned int	exp       : 11;
187 	unsigned int	sign      : 1;
188 	unsigned int	mantissa2 : 32;
189 };
190 
191 /* Vax double precision floating point */
192 struct  vax_double {
193 	unsigned int	mantissa1 : 7;
194 	unsigned int	exp       : 8;
195 	unsigned int	sign      : 1;
196 	unsigned int	mantissa2 : 16;
197 	unsigned int	mantissa3 : 16;
198 	unsigned int	mantissa4 : 16;
199 };
200 
201 #define VAX_DBL_BIAS	0x81
202 #define IEEE_DBL_BIAS	0x3ff
203 #define MASK(nbits)	((1 << nbits) - 1)
204 
205 static struct dbl_limits {
206 	struct	vax_double d;
207 	struct	ieee_double ieee;
208 } dbl_limits[2] = {
209 	{{ 0x7f, 0xff, 0x0, 0xffff, 0xffff, 0xffff },	/* Max Vax */
210 	{ 0x0, 0x7ff, 0x0, 0x0 }},			/* Max IEEE */
211 	{{ 0x0, 0x0, 0x0, 0x0, 0x0, 0x0},		/* Min Vax */
212 	{ 0x0, 0x0, 0x0, 0x0 }}				/* Min IEEE */
213 };
214 
215 #endif /* vax */
216 
217 
218 bool_t
219 xdr_double(xdrs, dp)
220 	XDR *xdrs;
221 	double *dp;
222 {
223 #ifdef IEEEFP
224 	int32_t *i32p;
225 	bool_t rv;
226 	long tmpl;
227 #else
228 	long *lp;
229 	struct	ieee_double id;
230 	struct	vax_double vd;
231 	struct dbl_limits *lim;
232 	int i;
233 #endif
234 
235 	switch (xdrs->x_op) {
236 
237 	case XDR_ENCODE:
238 #ifdef IEEEFP
239 		i32p = (int32_t *)(void *)dp;
240 #if BYTE_ORDER == BIG_ENDIAN
241 		tmpl = *i32p++;
242 		rv = XDR_PUTLONG(xdrs, &tmpl);
243 		if (!rv)
244 			return (rv);
245 		tmpl = *i32p;
246 		rv = XDR_PUTLONG(xdrs, &tmpl);
247 #else
248 		tmpl = *(i32p+1);
249 		rv = XDR_PUTLONG(xdrs, &tmpl);
250 		if (!rv)
251 			return (rv);
252 		tmpl = *i32p;
253 		rv = XDR_PUTLONG(xdrs, &tmpl);
254 #endif
255 		return (rv);
256 #else
257 		vd = *((struct vax_double *)dp);
258 		for (i = 0, lim = dbl_limits;
259 			i < sizeof(dbl_limits)/sizeof(struct dbl_limits);
260 			i++, lim++) {
261 			if ((vd.mantissa4 == lim->d.mantissa4) &&
262 				(vd.mantissa3 == lim->d.mantissa3) &&
263 				(vd.mantissa2 == lim->d.mantissa2) &&
264 				(vd.mantissa1 == lim->d.mantissa1) &&
265 				(vd.exp == lim->d.exp)) {
266 				id = lim->ieee;
267 				goto shipit;
268 			}
269 		}
270 		id.exp = vd.exp - VAX_DBL_BIAS + IEEE_DBL_BIAS;
271 		id.mantissa1 = (vd.mantissa1 << 13) | (vd.mantissa2 >> 3);
272 		id.mantissa2 = ((vd.mantissa2 & MASK(3)) << 29) |
273 				(vd.mantissa3 << 13) |
274 				((vd.mantissa4 >> 3) & MASK(13));
275 	shipit:
276 		id.sign = vd.sign;
277 		lp = (long *)&id;
278 		return (XDR_PUTLONG(xdrs, lp++) && XDR_PUTLONG(xdrs, lp));
279 #endif
280 
281 	case XDR_DECODE:
282 #ifdef IEEEFP
283 		i32p = (int32_t *)(void *)dp;
284 #if BYTE_ORDER == BIG_ENDIAN
285 		rv = XDR_GETLONG(xdrs, &tmpl);
286 		*i32p++ = tmpl;
287 		if (!rv)
288 			return (rv);
289 		rv = XDR_GETLONG(xdrs, &tmpl);
290 		*i32p = tmpl;
291 #else
292 		rv = XDR_GETLONG(xdrs, &tmpl);
293 		*(i32p+1) = (int32_t)tmpl;
294 		if (!rv)
295 			return (rv);
296 		rv = XDR_GETLONG(xdrs, &tmpl);
297 		*i32p = (int32_t)tmpl;
298 #endif
299 		return (rv);
300 #else
301 		lp = (long *)&id;
302 		if (!XDR_GETLONG(xdrs, lp++) || !XDR_GETLONG(xdrs, lp))
303 			return (FALSE);
304 		for (i = 0, lim = dbl_limits;
305 			i < sizeof(dbl_limits)/sizeof(struct dbl_limits);
306 			i++, lim++) {
307 			if ((id.mantissa2 == lim->ieee.mantissa2) &&
308 				(id.mantissa1 == lim->ieee.mantissa1) &&
309 				(id.exp == lim->ieee.exp)) {
310 				vd = lim->d;
311 				goto doneit;
312 			}
313 		}
314 		vd.exp = id.exp - IEEE_DBL_BIAS + VAX_DBL_BIAS;
315 		vd.mantissa1 = (id.mantissa1 >> 13);
316 		vd.mantissa2 = ((id.mantissa1 & MASK(13)) << 3) |
317 				(id.mantissa2 >> 29);
318 		vd.mantissa3 = (id.mantissa2 >> 13);
319 		vd.mantissa4 = (id.mantissa2 << 3);
320 	doneit:
321 		vd.sign = id.sign;
322 		*dp = *((double *)&vd);
323 		return (TRUE);
324 #endif
325 
326 	case XDR_FREE:
327 		return (TRUE);
328 	}
329 	/* NOTREACHED */
330 	return (FALSE);
331 }
332