xref: /freebsd/lib/libc/xdr/xdr_float.c (revision a0409676120c1e558d0ade943019934e0f15118d)
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 #include <sys/cdefs.h>
41 __FBSDID("$FreeBSD$");
42 
43 /*
44  * xdr_float.c, Generic XDR routines implementation.
45  *
46  * These are the "floating point" xdr routines used to (de)serialize
47  * most common data items.  See xdr.h for more info on the interface to
48  * xdr.
49  */
50 
51 #include "namespace.h"
52 #include <sys/param.h>
53 
54 #include <stdio.h>
55 
56 #include <rpc/types.h>
57 #include <rpc/xdr.h>
58 #include "un-namespace.h"
59 
60 /*
61  * NB: Not portable.
62  * This routine works on machines with IEEE754 FP and Vaxen.
63  */
64 
65 #include <machine/endian.h>
66 #define IEEEFP
67 
68 #if defined(__vax__)
69 
70 /* What IEEE single precision floating point looks like on a Vax */
71 struct	ieee_single {
72 	unsigned int	mantissa: 23;
73 	unsigned int	exp     : 8;
74 	unsigned int	sign    : 1;
75 };
76 
77 /* Vax single precision floating point */
78 struct	vax_single {
79 	unsigned int	mantissa1 : 7;
80 	unsigned int	exp       : 8;
81 	unsigned int	sign      : 1;
82 	unsigned int	mantissa2 : 16;
83 };
84 
85 #define VAX_SNG_BIAS	0x81
86 #define IEEE_SNG_BIAS	0x7f
87 
88 static struct sgl_limits {
89 	struct vax_single s;
90 	struct ieee_single ieee;
91 } sgl_limits[2] = {
92 	{{ 0x7f, 0xff, 0x0, 0xffff },	/* Max Vax */
93 	{ 0x0, 0xff, 0x0 }},		/* Max IEEE */
94 	{{ 0x0, 0x0, 0x0, 0x0 },	/* Min Vax */
95 	{ 0x0, 0x0, 0x0 }}		/* Min IEEE */
96 };
97 #endif /* vax */
98 
99 bool_t
100 xdr_float(XDR *xdrs, float *fp)
101 {
102 #ifndef IEEEFP
103 	struct ieee_single is;
104 	struct vax_single vs, *vsp;
105 	struct sgl_limits *lim;
106 	u_int i;
107 #endif
108 	switch (xdrs->x_op) {
109 
110 	case XDR_ENCODE:
111 #ifdef IEEEFP
112 		return (XDR_PUTINT32(xdrs, (int32_t *)fp));
113 #else
114 		vs = *((struct vax_single *)fp);
115 		for (i = 0, lim = sgl_limits; i < nitems(sgl_limits);
116 		    i++, lim++) {
117 			if ((vs.mantissa2 == lim->s.mantissa2) &&
118 				(vs.exp == lim->s.exp) &&
119 				(vs.mantissa1 == lim->s.mantissa1)) {
120 				is = lim->ieee;
121 				goto shipit;
122 			}
123 		}
124 		is.exp = vs.exp - VAX_SNG_BIAS + IEEE_SNG_BIAS;
125 		is.mantissa = (vs.mantissa1 << 16) | vs.mantissa2;
126 	shipit:
127 		is.sign = vs.sign;
128 		return (XDR_PUTINT32(xdrs, (int32_t *)&is));
129 #endif
130 
131 	case XDR_DECODE:
132 #ifdef IEEEFP
133 		return (XDR_GETINT32(xdrs, (int32_t *)fp));
134 #else
135 		vsp = (struct vax_single *)fp;
136 		if (!XDR_GETINT32(xdrs, (int32_t *)&is))
137 			return (FALSE);
138 		for (i = 0, lim = sgl_limits; i < nitems(sgl_limits);
139 		    i++, lim++) {
140 			if ((is.exp == lim->ieee.exp) &&
141 				(is.mantissa == lim->ieee.mantissa)) {
142 				*vsp = lim->s;
143 				goto doneit;
144 			}
145 		}
146 		vsp->exp = is.exp - IEEE_SNG_BIAS + VAX_SNG_BIAS;
147 		vsp->mantissa2 = is.mantissa;
148 		vsp->mantissa1 = (is.mantissa >> 16);
149 	doneit:
150 		vsp->sign = is.sign;
151 		return (TRUE);
152 #endif
153 
154 	case XDR_FREE:
155 		return (TRUE);
156 	}
157 	/* NOTREACHED */
158 	return (FALSE);
159 }
160 
161 #if defined(__vax__)
162 /* What IEEE double precision floating point looks like on a Vax */
163 struct	ieee_double {
164 	unsigned int	mantissa1 : 20;
165 	unsigned int	exp       : 11;
166 	unsigned int	sign      : 1;
167 	unsigned int	mantissa2 : 32;
168 };
169 
170 /* Vax double precision floating point */
171 struct  vax_double {
172 	unsigned int	mantissa1 : 7;
173 	unsigned int	exp       : 8;
174 	unsigned int	sign      : 1;
175 	unsigned int	mantissa2 : 16;
176 	unsigned int	mantissa3 : 16;
177 	unsigned int	mantissa4 : 16;
178 };
179 
180 #define VAX_DBL_BIAS	0x81
181 #define IEEE_DBL_BIAS	0x3ff
182 #define MASK(nbits)	((1 << nbits) - 1)
183 
184 static struct dbl_limits {
185 	struct	vax_double d;
186 	struct	ieee_double ieee;
187 } dbl_limits[2] = {
188 	{{ 0x7f, 0xff, 0x0, 0xffff, 0xffff, 0xffff },	/* Max Vax */
189 	{ 0x0, 0x7ff, 0x0, 0x0 }},			/* Max IEEE */
190 	{{ 0x0, 0x0, 0x0, 0x0, 0x0, 0x0},		/* Min Vax */
191 	{ 0x0, 0x0, 0x0, 0x0 }}				/* Min IEEE */
192 };
193 
194 #endif /* vax */
195 
196 
197 bool_t
198 xdr_double(XDR *xdrs, double *dp)
199 {
200 #ifdef IEEEFP
201 	int32_t *i32p;
202 	bool_t rv;
203 #else
204 	int32_t *lp;
205 	struct	ieee_double id;
206 	struct	vax_double vd;
207 	struct dbl_limits *lim;
208 	u_int i;
209 #endif
210 
211 	switch (xdrs->x_op) {
212 
213 	case XDR_ENCODE:
214 #ifdef IEEEFP
215 		i32p = (int32_t *)(void *)dp;
216 #if BYTE_ORDER == BIG_ENDIAN
217 		rv = XDR_PUTINT32(xdrs, i32p);
218 		if (!rv)
219 			return (rv);
220 		rv = XDR_PUTINT32(xdrs, i32p+1);
221 #else
222 		rv = XDR_PUTINT32(xdrs, i32p+1);
223 		if (!rv)
224 			return (rv);
225 		rv = XDR_PUTINT32(xdrs, i32p);
226 #endif
227 		return (rv);
228 #else
229 		vd = *((struct vax_double *)dp);
230 		for (i = 0, lim = dbl_limits; i < nitems(dbl_limits);
231 		    i++, lim++) {
232 			if ((vd.mantissa4 == lim->d.mantissa4) &&
233 				(vd.mantissa3 == lim->d.mantissa3) &&
234 				(vd.mantissa2 == lim->d.mantissa2) &&
235 				(vd.mantissa1 == lim->d.mantissa1) &&
236 				(vd.exp == lim->d.exp)) {
237 				id = lim->ieee;
238 				goto shipit;
239 			}
240 		}
241 		id.exp = vd.exp - VAX_DBL_BIAS + IEEE_DBL_BIAS;
242 		id.mantissa1 = (vd.mantissa1 << 13) | (vd.mantissa2 >> 3);
243 		id.mantissa2 = ((vd.mantissa2 & MASK(3)) << 29) |
244 				(vd.mantissa3 << 13) |
245 				((vd.mantissa4 >> 3) & MASK(13));
246 	shipit:
247 		id.sign = vd.sign;
248 		lp = (int32_t *)&id;
249 		return (XDR_PUTINT32(xdrs, lp++) && XDR_PUTINT32(xdrs, lp));
250 #endif
251 
252 	case XDR_DECODE:
253 #ifdef IEEEFP
254 		i32p = (int32_t *)(void *)dp;
255 #if BYTE_ORDER == BIG_ENDIAN
256 		rv = XDR_GETINT32(xdrs, i32p);
257 		if (!rv)
258 			return (rv);
259 		rv = XDR_GETINT32(xdrs, i32p+1);
260 #else
261 		rv = XDR_GETINT32(xdrs, i32p+1);
262 		if (!rv)
263 			return (rv);
264 		rv = XDR_GETINT32(xdrs, i32p);
265 #endif
266 		return (rv);
267 #else
268 		lp = (int32_t *)&id;
269 		if (!XDR_GETINT32(xdrs, lp++) || !XDR_GETINT32(xdrs, lp))
270 			return (FALSE);
271 		for (i = 0, lim = dbl_limits; i < nitems(dbl_limits);
272 		    i++, lim++) {
273 			if ((id.mantissa2 == lim->ieee.mantissa2) &&
274 				(id.mantissa1 == lim->ieee.mantissa1) &&
275 				(id.exp == lim->ieee.exp)) {
276 				vd = lim->d;
277 				goto doneit;
278 			}
279 		}
280 		vd.exp = id.exp - IEEE_DBL_BIAS + VAX_DBL_BIAS;
281 		vd.mantissa1 = (id.mantissa1 >> 13);
282 		vd.mantissa2 = ((id.mantissa1 & MASK(13)) << 3) |
283 				(id.mantissa2 >> 29);
284 		vd.mantissa3 = (id.mantissa2 >> 13);
285 		vd.mantissa4 = (id.mantissa2 << 3);
286 	doneit:
287 		vd.sign = id.sign;
288 		*dp = *((double *)&vd);
289 		return (TRUE);
290 #endif
291 
292 	case XDR_FREE:
293 		return (TRUE);
294 	}
295 	/* NOTREACHED */
296 	return (FALSE);
297 }
298