xref: /freebsd/lib/libc/xdr/xdr_float.c (revision 2008043f386721d58158e37e0d7e50df8095942d)
1 /*	$NetBSD: xdr_float.c,v 1.23 2000/07/17 04:59:51 matt Exp $	*/
2 
3 /*-
4  * SPDX-License-Identifier: BSD-3-Clause
5  *
6  * Copyright (c) 2010, Oracle America, Inc.
7  *
8  * Redistribution and use in source and binary forms, with or without
9  * modification, are permitted provided that the following conditions are
10  * met:
11  *
12  *     * Redistributions of source code must retain the above copyright
13  *       notice, this list of conditions and the following disclaimer.
14  *     * Redistributions in binary form must reproduce the above
15  *       copyright notice, this list of conditions and the following
16  *       disclaimer in the documentation and/or other materials
17  *       provided with the distribution.
18  *     * Neither the name of the "Oracle America, Inc." nor the names of its
19  *       contributors may be used to endorse or promote products derived
20  *       from this software without specific prior written permission.
21  *
22  *   THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
23  *   "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
24  *   LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
25  *   FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
26  *   COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT,
27  *   INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
28  *   DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE
29  *   GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
30  *   INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
31  *   WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
32  *   NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
33  *   OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
34  */
35 
36 #if defined(LIBC_SCCS) && !defined(lint)
37 static char *sccsid2 = "@(#)xdr_float.c 1.12 87/08/11 Copyr 1984 Sun Micro";
38 static char *sccsid = "@(#)xdr_float.c	2.1 88/07/29 4.0 RPCSRC";
39 #endif
40 /*
41  * xdr_float.c, Generic XDR routines implementation.
42  *
43  * These are the "floating point" xdr routines used to (de)serialize
44  * most common data items.  See xdr.h for more info on the interface to
45  * xdr.
46  */
47 
48 #include "namespace.h"
49 #include <sys/param.h>
50 
51 #include <stdio.h>
52 
53 #include <rpc/types.h>
54 #include <rpc/xdr.h>
55 #include "un-namespace.h"
56 
57 /*
58  * NB: Not portable.
59  * This routine works on machines with IEEE754 FP and Vaxen.
60  */
61 
62 #include <machine/endian.h>
63 #define IEEEFP
64 
65 #if defined(__vax__)
66 
67 /* What IEEE single precision floating point looks like on a Vax */
68 struct	ieee_single {
69 	unsigned int	mantissa: 23;
70 	unsigned int	exp     : 8;
71 	unsigned int	sign    : 1;
72 };
73 
74 /* Vax single precision floating point */
75 struct	vax_single {
76 	unsigned int	mantissa1 : 7;
77 	unsigned int	exp       : 8;
78 	unsigned int	sign      : 1;
79 	unsigned int	mantissa2 : 16;
80 };
81 
82 #define VAX_SNG_BIAS	0x81
83 #define IEEE_SNG_BIAS	0x7f
84 
85 static struct sgl_limits {
86 	struct vax_single s;
87 	struct ieee_single ieee;
88 } sgl_limits[2] = {
89 	{{ 0x7f, 0xff, 0x0, 0xffff },	/* Max Vax */
90 	{ 0x0, 0xff, 0x0 }},		/* Max IEEE */
91 	{{ 0x0, 0x0, 0x0, 0x0 },	/* Min Vax */
92 	{ 0x0, 0x0, 0x0 }}		/* Min IEEE */
93 };
94 #endif /* vax */
95 
96 bool_t
97 xdr_float(XDR *xdrs, float *fp)
98 {
99 #ifndef IEEEFP
100 	struct ieee_single is;
101 	struct vax_single vs, *vsp;
102 	struct sgl_limits *lim;
103 	u_int i;
104 #endif
105 	switch (xdrs->x_op) {
106 
107 	case XDR_ENCODE:
108 #ifdef IEEEFP
109 		return (XDR_PUTINT32(xdrs, (int32_t *)fp));
110 #else
111 		vs = *((struct vax_single *)fp);
112 		for (i = 0, lim = sgl_limits; i < nitems(sgl_limits);
113 		    i++, lim++) {
114 			if ((vs.mantissa2 == lim->s.mantissa2) &&
115 				(vs.exp == lim->s.exp) &&
116 				(vs.mantissa1 == lim->s.mantissa1)) {
117 				is = lim->ieee;
118 				goto shipit;
119 			}
120 		}
121 		is.exp = vs.exp - VAX_SNG_BIAS + IEEE_SNG_BIAS;
122 		is.mantissa = (vs.mantissa1 << 16) | vs.mantissa2;
123 	shipit:
124 		is.sign = vs.sign;
125 		return (XDR_PUTINT32(xdrs, (int32_t *)&is));
126 #endif
127 
128 	case XDR_DECODE:
129 #ifdef IEEEFP
130 		return (XDR_GETINT32(xdrs, (int32_t *)fp));
131 #else
132 		vsp = (struct vax_single *)fp;
133 		if (!XDR_GETINT32(xdrs, (int32_t *)&is))
134 			return (FALSE);
135 		for (i = 0, lim = sgl_limits; i < nitems(sgl_limits);
136 		    i++, lim++) {
137 			if ((is.exp == lim->ieee.exp) &&
138 				(is.mantissa == lim->ieee.mantissa)) {
139 				*vsp = lim->s;
140 				goto doneit;
141 			}
142 		}
143 		vsp->exp = is.exp - IEEE_SNG_BIAS + VAX_SNG_BIAS;
144 		vsp->mantissa2 = is.mantissa;
145 		vsp->mantissa1 = (is.mantissa >> 16);
146 	doneit:
147 		vsp->sign = is.sign;
148 		return (TRUE);
149 #endif
150 
151 	case XDR_FREE:
152 		return (TRUE);
153 	}
154 	/* NOTREACHED */
155 	return (FALSE);
156 }
157 
158 #if defined(__vax__)
159 /* What IEEE double precision floating point looks like on a Vax */
160 struct	ieee_double {
161 	unsigned int	mantissa1 : 20;
162 	unsigned int	exp       : 11;
163 	unsigned int	sign      : 1;
164 	unsigned int	mantissa2 : 32;
165 };
166 
167 /* Vax double precision floating point */
168 struct  vax_double {
169 	unsigned int	mantissa1 : 7;
170 	unsigned int	exp       : 8;
171 	unsigned int	sign      : 1;
172 	unsigned int	mantissa2 : 16;
173 	unsigned int	mantissa3 : 16;
174 	unsigned int	mantissa4 : 16;
175 };
176 
177 #define VAX_DBL_BIAS	0x81
178 #define IEEE_DBL_BIAS	0x3ff
179 #define MASK(nbits)	((1 << nbits) - 1)
180 
181 static struct dbl_limits {
182 	struct	vax_double d;
183 	struct	ieee_double ieee;
184 } dbl_limits[2] = {
185 	{{ 0x7f, 0xff, 0x0, 0xffff, 0xffff, 0xffff },	/* Max Vax */
186 	{ 0x0, 0x7ff, 0x0, 0x0 }},			/* Max IEEE */
187 	{{ 0x0, 0x0, 0x0, 0x0, 0x0, 0x0},		/* Min Vax */
188 	{ 0x0, 0x0, 0x0, 0x0 }}				/* Min IEEE */
189 };
190 
191 #endif /* vax */
192 
193 
194 bool_t
195 xdr_double(XDR *xdrs, double *dp)
196 {
197 #ifdef IEEEFP
198 	int32_t *i32p;
199 	bool_t rv;
200 #else
201 	int32_t *lp;
202 	struct	ieee_double id;
203 	struct	vax_double vd;
204 	struct dbl_limits *lim;
205 	u_int i;
206 #endif
207 
208 	switch (xdrs->x_op) {
209 
210 	case XDR_ENCODE:
211 #ifdef IEEEFP
212 		i32p = (int32_t *)(void *)dp;
213 #if BYTE_ORDER == BIG_ENDIAN
214 		rv = XDR_PUTINT32(xdrs, i32p);
215 		if (!rv)
216 			return (rv);
217 		rv = XDR_PUTINT32(xdrs, i32p+1);
218 #else
219 		rv = XDR_PUTINT32(xdrs, i32p+1);
220 		if (!rv)
221 			return (rv);
222 		rv = XDR_PUTINT32(xdrs, i32p);
223 #endif
224 		return (rv);
225 #else
226 		vd = *((struct vax_double *)dp);
227 		for (i = 0, lim = dbl_limits; i < nitems(dbl_limits);
228 		    i++, lim++) {
229 			if ((vd.mantissa4 == lim->d.mantissa4) &&
230 				(vd.mantissa3 == lim->d.mantissa3) &&
231 				(vd.mantissa2 == lim->d.mantissa2) &&
232 				(vd.mantissa1 == lim->d.mantissa1) &&
233 				(vd.exp == lim->d.exp)) {
234 				id = lim->ieee;
235 				goto shipit;
236 			}
237 		}
238 		id.exp = vd.exp - VAX_DBL_BIAS + IEEE_DBL_BIAS;
239 		id.mantissa1 = (vd.mantissa1 << 13) | (vd.mantissa2 >> 3);
240 		id.mantissa2 = ((vd.mantissa2 & MASK(3)) << 29) |
241 				(vd.mantissa3 << 13) |
242 				((vd.mantissa4 >> 3) & MASK(13));
243 	shipit:
244 		id.sign = vd.sign;
245 		lp = (int32_t *)&id;
246 		return (XDR_PUTINT32(xdrs, lp++) && XDR_PUTINT32(xdrs, lp));
247 #endif
248 
249 	case XDR_DECODE:
250 #ifdef IEEEFP
251 		i32p = (int32_t *)(void *)dp;
252 #if BYTE_ORDER == BIG_ENDIAN
253 		rv = XDR_GETINT32(xdrs, i32p);
254 		if (!rv)
255 			return (rv);
256 		rv = XDR_GETINT32(xdrs, i32p+1);
257 #else
258 		rv = XDR_GETINT32(xdrs, i32p+1);
259 		if (!rv)
260 			return (rv);
261 		rv = XDR_GETINT32(xdrs, i32p);
262 #endif
263 		return (rv);
264 #else
265 		lp = (int32_t *)&id;
266 		if (!XDR_GETINT32(xdrs, lp++) || !XDR_GETINT32(xdrs, lp))
267 			return (FALSE);
268 		for (i = 0, lim = dbl_limits; i < nitems(dbl_limits);
269 		    i++, lim++) {
270 			if ((id.mantissa2 == lim->ieee.mantissa2) &&
271 				(id.mantissa1 == lim->ieee.mantissa1) &&
272 				(id.exp == lim->ieee.exp)) {
273 				vd = lim->d;
274 				goto doneit;
275 			}
276 		}
277 		vd.exp = id.exp - IEEE_DBL_BIAS + VAX_DBL_BIAS;
278 		vd.mantissa1 = (id.mantissa1 >> 13);
279 		vd.mantissa2 = ((id.mantissa1 & MASK(13)) << 3) |
280 				(id.mantissa2 >> 29);
281 		vd.mantissa3 = (id.mantissa2 >> 13);
282 		vd.mantissa4 = (id.mantissa2 << 3);
283 	doneit:
284 		vd.sign = id.sign;
285 		*dp = *((double *)&vd);
286 		return (TRUE);
287 #endif
288 
289 	case XDR_FREE:
290 		return (TRUE);
291 	}
292 	/* NOTREACHED */
293 	return (FALSE);
294 }
295