xref: /freebsd/lib/libc/xdr/xdr_float.c (revision b2d48be1bc7df45ddd13b143a160d0acb5a383c5)
1 /*	$NetBSD: xdr_float.c,v 1.23 2000/07/17 04:59:51 matt Exp $	*/
2 
3 /*-
4  * Copyright (c) 2010, Oracle America, Inc.
5  *
6  * Redistribution and use in source and binary forms, with or without
7  * modification, are permitted provided that the following conditions are
8  * met:
9  *
10  *     * Redistributions of source code must retain the above copyright
11  *       notice, this list of conditions and the following disclaimer.
12  *     * Redistributions in binary form must reproduce the above
13  *       copyright notice, this list of conditions and the following
14  *       disclaimer in the documentation and/or other materials
15  *       provided with the distribution.
16  *     * Neither the name of the "Oracle America, Inc." nor the names of its
17  *       contributors may be used to endorse or promote products derived
18  *       from this software without specific prior written permission.
19  *
20  *   THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
21  *   "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
22  *   LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
23  *   FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
24  *   COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT,
25  *   INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
26  *   DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE
27  *   GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
28  *   INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
29  *   WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
30  *   NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
31  *   OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
32  */
33 
34 #if defined(LIBC_SCCS) && !defined(lint)
35 static char *sccsid2 = "@(#)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 #endif
38 #include <sys/cdefs.h>
39 __FBSDID("$FreeBSD$");
40 
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/types.h>
51 #include <sys/param.h>
52 
53 #include <stdio.h>
54 
55 #include <rpc/types.h>
56 #include <rpc/xdr.h>
57 #include "un-namespace.h"
58 
59 /*
60  * NB: Not portable.
61  * This routine works on machines with IEEE754 FP and Vaxen.
62  */
63 
64 #if defined(__m68k__) || defined(__sparc__) || defined(__i386__) || \
65     defined(__mips__) || defined(__ns32k__) || defined(__alpha__) || \
66     defined(__arm__) || defined(__ppc__) || \
67     defined(__arm26__) || defined(__sparc64__) || defined(__amd64__) || \
68     defined(__aarch64__)
69 #include <machine/endian.h>
70 #define IEEEFP
71 #endif
72 
73 #if defined(__vax__)
74 
75 /* What IEEE single precision floating point looks like on a Vax */
76 struct	ieee_single {
77 	unsigned int	mantissa: 23;
78 	unsigned int	exp     : 8;
79 	unsigned int	sign    : 1;
80 };
81 
82 /* Vax single precision floating point */
83 struct	vax_single {
84 	unsigned int	mantissa1 : 7;
85 	unsigned int	exp       : 8;
86 	unsigned int	sign      : 1;
87 	unsigned int	mantissa2 : 16;
88 };
89 
90 #define VAX_SNG_BIAS	0x81
91 #define IEEE_SNG_BIAS	0x7f
92 
93 static struct sgl_limits {
94 	struct vax_single s;
95 	struct ieee_single ieee;
96 } sgl_limits[2] = {
97 	{{ 0x7f, 0xff, 0x0, 0xffff },	/* Max Vax */
98 	{ 0x0, 0xff, 0x0 }},		/* Max IEEE */
99 	{{ 0x0, 0x0, 0x0, 0x0 },	/* Min Vax */
100 	{ 0x0, 0x0, 0x0 }}		/* Min IEEE */
101 };
102 #endif /* vax */
103 
104 bool_t
105 xdr_float(XDR *xdrs, float *fp)
106 {
107 #ifndef IEEEFP
108 	struct ieee_single is;
109 	struct vax_single vs, *vsp;
110 	struct sgl_limits *lim;
111 	int i;
112 #endif
113 	switch (xdrs->x_op) {
114 
115 	case XDR_ENCODE:
116 #ifdef IEEEFP
117 		return (XDR_PUTINT32(xdrs, (int32_t *)fp));
118 #else
119 		vs = *((struct vax_single *)fp);
120 		for (i = 0, lim = sgl_limits;
121 			i < sizeof(sgl_limits)/sizeof(struct sgl_limits);
122 			i++, lim++) {
123 			if ((vs.mantissa2 == lim->s.mantissa2) &&
124 				(vs.exp == lim->s.exp) &&
125 				(vs.mantissa1 == lim->s.mantissa1)) {
126 				is = lim->ieee;
127 				goto shipit;
128 			}
129 		}
130 		is.exp = vs.exp - VAX_SNG_BIAS + IEEE_SNG_BIAS;
131 		is.mantissa = (vs.mantissa1 << 16) | vs.mantissa2;
132 	shipit:
133 		is.sign = vs.sign;
134 		return (XDR_PUTINT32(xdrs, (int32_t *)&is));
135 #endif
136 
137 	case XDR_DECODE:
138 #ifdef IEEEFP
139 		return (XDR_GETINT32(xdrs, (int32_t *)fp));
140 #else
141 		vsp = (struct vax_single *)fp;
142 		if (!XDR_GETINT32(xdrs, (int32_t *)&is))
143 			return (FALSE);
144 		for (i = 0, lim = sgl_limits;
145 			i < sizeof(sgl_limits)/sizeof(struct sgl_limits);
146 			i++, lim++) {
147 			if ((is.exp == lim->ieee.exp) &&
148 				(is.mantissa == lim->ieee.mantissa)) {
149 				*vsp = lim->s;
150 				goto doneit;
151 			}
152 		}
153 		vsp->exp = is.exp - IEEE_SNG_BIAS + VAX_SNG_BIAS;
154 		vsp->mantissa2 = is.mantissa;
155 		vsp->mantissa1 = (is.mantissa >> 16);
156 	doneit:
157 		vsp->sign = is.sign;
158 		return (TRUE);
159 #endif
160 
161 	case XDR_FREE:
162 		return (TRUE);
163 	}
164 	/* NOTREACHED */
165 	return (FALSE);
166 }
167 
168 #if defined(__vax__)
169 /* What IEEE double precision floating point looks like on a Vax */
170 struct	ieee_double {
171 	unsigned int	mantissa1 : 20;
172 	unsigned int	exp       : 11;
173 	unsigned int	sign      : 1;
174 	unsigned int	mantissa2 : 32;
175 };
176 
177 /* Vax double precision floating point */
178 struct  vax_double {
179 	unsigned int	mantissa1 : 7;
180 	unsigned int	exp       : 8;
181 	unsigned int	sign      : 1;
182 	unsigned int	mantissa2 : 16;
183 	unsigned int	mantissa3 : 16;
184 	unsigned int	mantissa4 : 16;
185 };
186 
187 #define VAX_DBL_BIAS	0x81
188 #define IEEE_DBL_BIAS	0x3ff
189 #define MASK(nbits)	((1 << nbits) - 1)
190 
191 static struct dbl_limits {
192 	struct	vax_double d;
193 	struct	ieee_double ieee;
194 } dbl_limits[2] = {
195 	{{ 0x7f, 0xff, 0x0, 0xffff, 0xffff, 0xffff },	/* Max Vax */
196 	{ 0x0, 0x7ff, 0x0, 0x0 }},			/* Max IEEE */
197 	{{ 0x0, 0x0, 0x0, 0x0, 0x0, 0x0},		/* Min Vax */
198 	{ 0x0, 0x0, 0x0, 0x0 }}				/* Min IEEE */
199 };
200 
201 #endif /* vax */
202 
203 
204 bool_t
205 xdr_double(XDR *xdrs, double *dp)
206 {
207 #ifdef IEEEFP
208 	int32_t *i32p;
209 	bool_t rv;
210 #else
211 	int32_t *lp;
212 	struct	ieee_double id;
213 	struct	vax_double vd;
214 	struct dbl_limits *lim;
215 	int i;
216 #endif
217 
218 	switch (xdrs->x_op) {
219 
220 	case XDR_ENCODE:
221 #ifdef IEEEFP
222 		i32p = (int32_t *)(void *)dp;
223 #if BYTE_ORDER == BIG_ENDIAN
224 		rv = XDR_PUTINT32(xdrs, i32p);
225 		if (!rv)
226 			return (rv);
227 		rv = XDR_PUTINT32(xdrs, i32p+1);
228 #else
229 		rv = XDR_PUTINT32(xdrs, i32p+1);
230 		if (!rv)
231 			return (rv);
232 		rv = XDR_PUTINT32(xdrs, i32p);
233 #endif
234 		return (rv);
235 #else
236 		vd = *((struct vax_double *)dp);
237 		for (i = 0, lim = dbl_limits;
238 			i < sizeof(dbl_limits)/sizeof(struct dbl_limits);
239 			i++, lim++) {
240 			if ((vd.mantissa4 == lim->d.mantissa4) &&
241 				(vd.mantissa3 == lim->d.mantissa3) &&
242 				(vd.mantissa2 == lim->d.mantissa2) &&
243 				(vd.mantissa1 == lim->d.mantissa1) &&
244 				(vd.exp == lim->d.exp)) {
245 				id = lim->ieee;
246 				goto shipit;
247 			}
248 		}
249 		id.exp = vd.exp - VAX_DBL_BIAS + IEEE_DBL_BIAS;
250 		id.mantissa1 = (vd.mantissa1 << 13) | (vd.mantissa2 >> 3);
251 		id.mantissa2 = ((vd.mantissa2 & MASK(3)) << 29) |
252 				(vd.mantissa3 << 13) |
253 				((vd.mantissa4 >> 3) & MASK(13));
254 	shipit:
255 		id.sign = vd.sign;
256 		lp = (int32_t *)&id;
257 		return (XDR_PUTINT32(xdrs, lp++) && XDR_PUTINT32(xdrs, lp));
258 #endif
259 
260 	case XDR_DECODE:
261 #ifdef IEEEFP
262 		i32p = (int32_t *)(void *)dp;
263 #if BYTE_ORDER == BIG_ENDIAN
264 		rv = XDR_GETINT32(xdrs, i32p);
265 		if (!rv)
266 			return (rv);
267 		rv = XDR_GETINT32(xdrs, i32p+1);
268 #else
269 		rv = XDR_GETINT32(xdrs, i32p+1);
270 		if (!rv)
271 			return (rv);
272 		rv = XDR_GETINT32(xdrs, i32p);
273 #endif
274 		return (rv);
275 #else
276 		lp = (int32_t *)&id;
277 		if (!XDR_GETINT32(xdrs, lp++) || !XDR_GETINT32(xdrs, lp))
278 			return (FALSE);
279 		for (i = 0, lim = dbl_limits;
280 			i < sizeof(dbl_limits)/sizeof(struct dbl_limits);
281 			i++, lim++) {
282 			if ((id.mantissa2 == lim->ieee.mantissa2) &&
283 				(id.mantissa1 == lim->ieee.mantissa1) &&
284 				(id.exp == lim->ieee.exp)) {
285 				vd = lim->d;
286 				goto doneit;
287 			}
288 		}
289 		vd.exp = id.exp - IEEE_DBL_BIAS + VAX_DBL_BIAS;
290 		vd.mantissa1 = (id.mantissa1 >> 13);
291 		vd.mantissa2 = ((id.mantissa1 & MASK(13)) << 3) |
292 				(id.mantissa2 >> 29);
293 		vd.mantissa3 = (id.mantissa2 >> 13);
294 		vd.mantissa4 = (id.mantissa2 << 3);
295 	doneit:
296 		vd.sign = id.sign;
297 		*dp = *((double *)&vd);
298 		return (TRUE);
299 #endif
300 
301 	case XDR_FREE:
302 		return (TRUE);
303 	}
304 	/* NOTREACHED */
305 	return (FALSE);
306 }
307