xref: /freebsd/lib/libc/xdr/xdr_float.c (revision 22cf89c938886d14f5796fc49f9f020c23ea8eaf)
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 /*
42  * xdr_float.c, Generic XDR routines implementation.
43  *
44  * These are the "floating point" xdr routines used to (de)serialize
45  * most common data items.  See xdr.h for more info on the interface to
46  * xdr.
47  */
48 
49 #include "namespace.h"
50 #include <sys/param.h>
51 
52 #include <stdio.h>
53 
54 #include <rpc/types.h>
55 #include <rpc/xdr.h>
56 #include "un-namespace.h"
57 
58 /*
59  * NB: Not portable.
60  * This routine works on machines with IEEE754 FP and Vaxen.
61  */
62 
63 #include <machine/endian.h>
64 #define IEEEFP
65 
66 #if defined(__vax__)
67 
68 /* What IEEE single precision floating point looks like on a Vax */
69 struct	ieee_single {
70 	unsigned int	mantissa: 23;
71 	unsigned int	exp     : 8;
72 	unsigned int	sign    : 1;
73 };
74 
75 /* Vax single precision floating point */
76 struct	vax_single {
77 	unsigned int	mantissa1 : 7;
78 	unsigned int	exp       : 8;
79 	unsigned int	sign      : 1;
80 	unsigned int	mantissa2 : 16;
81 };
82 
83 #define VAX_SNG_BIAS	0x81
84 #define IEEE_SNG_BIAS	0x7f
85 
86 static struct sgl_limits {
87 	struct vax_single s;
88 	struct ieee_single ieee;
89 } sgl_limits[2] = {
90 	{{ 0x7f, 0xff, 0x0, 0xffff },	/* Max Vax */
91 	{ 0x0, 0xff, 0x0 }},		/* Max IEEE */
92 	{{ 0x0, 0x0, 0x0, 0x0 },	/* Min Vax */
93 	{ 0x0, 0x0, 0x0 }}		/* Min IEEE */
94 };
95 #endif /* vax */
96 
97 bool_t
98 xdr_float(XDR *xdrs, float *fp)
99 {
100 #ifndef IEEEFP
101 	struct ieee_single is;
102 	struct vax_single vs, *vsp;
103 	struct sgl_limits *lim;
104 	u_int i;
105 #endif
106 	switch (xdrs->x_op) {
107 
108 	case XDR_ENCODE:
109 #ifdef IEEEFP
110 		return (XDR_PUTINT32(xdrs, (int32_t *)fp));
111 #else
112 		vs = *((struct vax_single *)fp);
113 		for (i = 0, lim = sgl_limits; i < nitems(sgl_limits);
114 		    i++, lim++) {
115 			if ((vs.mantissa2 == lim->s.mantissa2) &&
116 				(vs.exp == lim->s.exp) &&
117 				(vs.mantissa1 == lim->s.mantissa1)) {
118 				is = lim->ieee;
119 				goto shipit;
120 			}
121 		}
122 		is.exp = vs.exp - VAX_SNG_BIAS + IEEE_SNG_BIAS;
123 		is.mantissa = (vs.mantissa1 << 16) | vs.mantissa2;
124 	shipit:
125 		is.sign = vs.sign;
126 		return (XDR_PUTINT32(xdrs, (int32_t *)&is));
127 #endif
128 
129 	case XDR_DECODE:
130 #ifdef IEEEFP
131 		return (XDR_GETINT32(xdrs, (int32_t *)fp));
132 #else
133 		vsp = (struct vax_single *)fp;
134 		if (!XDR_GETINT32(xdrs, (int32_t *)&is))
135 			return (FALSE);
136 		for (i = 0, lim = sgl_limits; i < nitems(sgl_limits);
137 		    i++, lim++) {
138 			if ((is.exp == lim->ieee.exp) &&
139 				(is.mantissa == lim->ieee.mantissa)) {
140 				*vsp = lim->s;
141 				goto doneit;
142 			}
143 		}
144 		vsp->exp = is.exp - IEEE_SNG_BIAS + VAX_SNG_BIAS;
145 		vsp->mantissa2 = is.mantissa;
146 		vsp->mantissa1 = (is.mantissa >> 16);
147 	doneit:
148 		vsp->sign = is.sign;
149 		return (TRUE);
150 #endif
151 
152 	case XDR_FREE:
153 		return (TRUE);
154 	}
155 	/* NOTREACHED */
156 	return (FALSE);
157 }
158 
159 #if defined(__vax__)
160 /* What IEEE double precision floating point looks like on a Vax */
161 struct	ieee_double {
162 	unsigned int	mantissa1 : 20;
163 	unsigned int	exp       : 11;
164 	unsigned int	sign      : 1;
165 	unsigned int	mantissa2 : 32;
166 };
167 
168 /* Vax double precision floating point */
169 struct  vax_double {
170 	unsigned int	mantissa1 : 7;
171 	unsigned int	exp       : 8;
172 	unsigned int	sign      : 1;
173 	unsigned int	mantissa2 : 16;
174 	unsigned int	mantissa3 : 16;
175 	unsigned int	mantissa4 : 16;
176 };
177 
178 #define VAX_DBL_BIAS	0x81
179 #define IEEE_DBL_BIAS	0x3ff
180 #define MASK(nbits)	((1 << nbits) - 1)
181 
182 static struct dbl_limits {
183 	struct	vax_double d;
184 	struct	ieee_double ieee;
185 } dbl_limits[2] = {
186 	{{ 0x7f, 0xff, 0x0, 0xffff, 0xffff, 0xffff },	/* Max Vax */
187 	{ 0x0, 0x7ff, 0x0, 0x0 }},			/* Max IEEE */
188 	{{ 0x0, 0x0, 0x0, 0x0, 0x0, 0x0},		/* Min Vax */
189 	{ 0x0, 0x0, 0x0, 0x0 }}				/* Min IEEE */
190 };
191 
192 #endif /* vax */
193 
194 
195 bool_t
196 xdr_double(XDR *xdrs, double *dp)
197 {
198 #ifdef IEEEFP
199 	int32_t *i32p;
200 	bool_t rv;
201 #else
202 	int32_t *lp;
203 	struct	ieee_double id;
204 	struct	vax_double vd;
205 	struct dbl_limits *lim;
206 	u_int i;
207 #endif
208 
209 	switch (xdrs->x_op) {
210 
211 	case XDR_ENCODE:
212 #ifdef IEEEFP
213 		i32p = (int32_t *)(void *)dp;
214 #if BYTE_ORDER == BIG_ENDIAN
215 		rv = XDR_PUTINT32(xdrs, i32p);
216 		if (!rv)
217 			return (rv);
218 		rv = XDR_PUTINT32(xdrs, i32p+1);
219 #else
220 		rv = XDR_PUTINT32(xdrs, i32p+1);
221 		if (!rv)
222 			return (rv);
223 		rv = XDR_PUTINT32(xdrs, i32p);
224 #endif
225 		return (rv);
226 #else
227 		vd = *((struct vax_double *)dp);
228 		for (i = 0, lim = dbl_limits; i < nitems(dbl_limits);
229 		    i++, lim++) {
230 			if ((vd.mantissa4 == lim->d.mantissa4) &&
231 				(vd.mantissa3 == lim->d.mantissa3) &&
232 				(vd.mantissa2 == lim->d.mantissa2) &&
233 				(vd.mantissa1 == lim->d.mantissa1) &&
234 				(vd.exp == lim->d.exp)) {
235 				id = lim->ieee;
236 				goto shipit;
237 			}
238 		}
239 		id.exp = vd.exp - VAX_DBL_BIAS + IEEE_DBL_BIAS;
240 		id.mantissa1 = (vd.mantissa1 << 13) | (vd.mantissa2 >> 3);
241 		id.mantissa2 = ((vd.mantissa2 & MASK(3)) << 29) |
242 				(vd.mantissa3 << 13) |
243 				((vd.mantissa4 >> 3) & MASK(13));
244 	shipit:
245 		id.sign = vd.sign;
246 		lp = (int32_t *)&id;
247 		return (XDR_PUTINT32(xdrs, lp++) && XDR_PUTINT32(xdrs, lp));
248 #endif
249 
250 	case XDR_DECODE:
251 #ifdef IEEEFP
252 		i32p = (int32_t *)(void *)dp;
253 #if BYTE_ORDER == BIG_ENDIAN
254 		rv = XDR_GETINT32(xdrs, i32p);
255 		if (!rv)
256 			return (rv);
257 		rv = XDR_GETINT32(xdrs, i32p+1);
258 #else
259 		rv = XDR_GETINT32(xdrs, i32p+1);
260 		if (!rv)
261 			return (rv);
262 		rv = XDR_GETINT32(xdrs, i32p);
263 #endif
264 		return (rv);
265 #else
266 		lp = (int32_t *)&id;
267 		if (!XDR_GETINT32(xdrs, lp++) || !XDR_GETINT32(xdrs, lp))
268 			return (FALSE);
269 		for (i = 0, lim = dbl_limits; i < nitems(dbl_limits);
270 		    i++, lim++) {
271 			if ((id.mantissa2 == lim->ieee.mantissa2) &&
272 				(id.mantissa1 == lim->ieee.mantissa1) &&
273 				(id.exp == lim->ieee.exp)) {
274 				vd = lim->d;
275 				goto doneit;
276 			}
277 		}
278 		vd.exp = id.exp - IEEE_DBL_BIAS + VAX_DBL_BIAS;
279 		vd.mantissa1 = (id.mantissa1 >> 13);
280 		vd.mantissa2 = ((id.mantissa1 & MASK(13)) << 3) |
281 				(id.mantissa2 >> 29);
282 		vd.mantissa3 = (id.mantissa2 >> 13);
283 		vd.mantissa4 = (id.mantissa2 << 3);
284 	doneit:
285 		vd.sign = id.sign;
286 		*dp = *((double *)&vd);
287 		return (TRUE);
288 #endif
289 
290 	case XDR_FREE:
291 		return (TRUE);
292 	}
293 	/* NOTREACHED */
294 	return (FALSE);
295 }
296