xref: /freebsd/lib/libc/xdr/xdr_float.c (revision 3e5645b78f476816ca3b5acc28b29bbafbb9c444)
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(xdrs, fp)
106 	XDR *xdrs;
107 	float *fp;
108 {
109 #ifndef IEEEFP
110 	struct ieee_single is;
111 	struct vax_single vs, *vsp;
112 	struct sgl_limits *lim;
113 	int i;
114 #endif
115 	switch (xdrs->x_op) {
116 
117 	case XDR_ENCODE:
118 #ifdef IEEEFP
119 		return (XDR_PUTINT32(xdrs, (int32_t *)fp));
120 #else
121 		vs = *((struct vax_single *)fp);
122 		for (i = 0, lim = sgl_limits;
123 			i < sizeof(sgl_limits)/sizeof(struct sgl_limits);
124 			i++, lim++) {
125 			if ((vs.mantissa2 == lim->s.mantissa2) &&
126 				(vs.exp == lim->s.exp) &&
127 				(vs.mantissa1 == lim->s.mantissa1)) {
128 				is = lim->ieee;
129 				goto shipit;
130 			}
131 		}
132 		is.exp = vs.exp - VAX_SNG_BIAS + IEEE_SNG_BIAS;
133 		is.mantissa = (vs.mantissa1 << 16) | vs.mantissa2;
134 	shipit:
135 		is.sign = vs.sign;
136 		return (XDR_PUTINT32(xdrs, (int32_t *)&is));
137 #endif
138 
139 	case XDR_DECODE:
140 #ifdef IEEEFP
141 		return (XDR_GETINT32(xdrs, (int32_t *)fp));
142 #else
143 		vsp = (struct vax_single *)fp;
144 		if (!XDR_GETINT32(xdrs, (int32_t *)&is))
145 			return (FALSE);
146 		for (i = 0, lim = sgl_limits;
147 			i < sizeof(sgl_limits)/sizeof(struct sgl_limits);
148 			i++, lim++) {
149 			if ((is.exp == lim->ieee.exp) &&
150 				(is.mantissa == lim->ieee.mantissa)) {
151 				*vsp = lim->s;
152 				goto doneit;
153 			}
154 		}
155 		vsp->exp = is.exp - IEEE_SNG_BIAS + VAX_SNG_BIAS;
156 		vsp->mantissa2 = is.mantissa;
157 		vsp->mantissa1 = (is.mantissa >> 16);
158 	doneit:
159 		vsp->sign = is.sign;
160 		return (TRUE);
161 #endif
162 
163 	case XDR_FREE:
164 		return (TRUE);
165 	}
166 	/* NOTREACHED */
167 	return (FALSE);
168 }
169 
170 #if defined(__vax__)
171 /* What IEEE double precision floating point looks like on a Vax */
172 struct	ieee_double {
173 	unsigned int	mantissa1 : 20;
174 	unsigned int	exp       : 11;
175 	unsigned int	sign      : 1;
176 	unsigned int	mantissa2 : 32;
177 };
178 
179 /* Vax double precision floating point */
180 struct  vax_double {
181 	unsigned int	mantissa1 : 7;
182 	unsigned int	exp       : 8;
183 	unsigned int	sign      : 1;
184 	unsigned int	mantissa2 : 16;
185 	unsigned int	mantissa3 : 16;
186 	unsigned int	mantissa4 : 16;
187 };
188 
189 #define VAX_DBL_BIAS	0x81
190 #define IEEE_DBL_BIAS	0x3ff
191 #define MASK(nbits)	((1 << nbits) - 1)
192 
193 static struct dbl_limits {
194 	struct	vax_double d;
195 	struct	ieee_double ieee;
196 } dbl_limits[2] = {
197 	{{ 0x7f, 0xff, 0x0, 0xffff, 0xffff, 0xffff },	/* Max Vax */
198 	{ 0x0, 0x7ff, 0x0, 0x0 }},			/* Max IEEE */
199 	{{ 0x0, 0x0, 0x0, 0x0, 0x0, 0x0},		/* Min Vax */
200 	{ 0x0, 0x0, 0x0, 0x0 }}				/* Min IEEE */
201 };
202 
203 #endif /* vax */
204 
205 
206 bool_t
207 xdr_double(xdrs, dp)
208 	XDR *xdrs;
209 	double *dp;
210 {
211 #ifdef IEEEFP
212 	int32_t *i32p;
213 	bool_t rv;
214 #else
215 	int32_t *lp;
216 	struct	ieee_double id;
217 	struct	vax_double vd;
218 	struct dbl_limits *lim;
219 	int i;
220 #endif
221 
222 	switch (xdrs->x_op) {
223 
224 	case XDR_ENCODE:
225 #ifdef IEEEFP
226 		i32p = (int32_t *)(void *)dp;
227 #if BYTE_ORDER == BIG_ENDIAN
228 		rv = XDR_PUTINT32(xdrs, i32p);
229 		if (!rv)
230 			return (rv);
231 		rv = XDR_PUTINT32(xdrs, i32p+1);
232 #else
233 		rv = XDR_PUTINT32(xdrs, i32p+1);
234 		if (!rv)
235 			return (rv);
236 		rv = XDR_PUTINT32(xdrs, i32p);
237 #endif
238 		return (rv);
239 #else
240 		vd = *((struct vax_double *)dp);
241 		for (i = 0, lim = dbl_limits;
242 			i < sizeof(dbl_limits)/sizeof(struct dbl_limits);
243 			i++, lim++) {
244 			if ((vd.mantissa4 == lim->d.mantissa4) &&
245 				(vd.mantissa3 == lim->d.mantissa3) &&
246 				(vd.mantissa2 == lim->d.mantissa2) &&
247 				(vd.mantissa1 == lim->d.mantissa1) &&
248 				(vd.exp == lim->d.exp)) {
249 				id = lim->ieee;
250 				goto shipit;
251 			}
252 		}
253 		id.exp = vd.exp - VAX_DBL_BIAS + IEEE_DBL_BIAS;
254 		id.mantissa1 = (vd.mantissa1 << 13) | (vd.mantissa2 >> 3);
255 		id.mantissa2 = ((vd.mantissa2 & MASK(3)) << 29) |
256 				(vd.mantissa3 << 13) |
257 				((vd.mantissa4 >> 3) & MASK(13));
258 	shipit:
259 		id.sign = vd.sign;
260 		lp = (int32_t *)&id;
261 		return (XDR_PUTINT32(xdrs, lp++) && XDR_PUTINT32(xdrs, lp));
262 #endif
263 
264 	case XDR_DECODE:
265 #ifdef IEEEFP
266 		i32p = (int32_t *)(void *)dp;
267 #if BYTE_ORDER == BIG_ENDIAN
268 		rv = XDR_GETINT32(xdrs, i32p);
269 		if (!rv)
270 			return (rv);
271 		rv = XDR_GETINT32(xdrs, i32p+1);
272 #else
273 		rv = XDR_GETINT32(xdrs, i32p+1);
274 		if (!rv)
275 			return (rv);
276 		rv = XDR_GETINT32(xdrs, i32p);
277 #endif
278 		return (rv);
279 #else
280 		lp = (int32_t *)&id;
281 		if (!XDR_GETINT32(xdrs, lp++) || !XDR_GETINT32(xdrs, lp))
282 			return (FALSE);
283 		for (i = 0, lim = dbl_limits;
284 			i < sizeof(dbl_limits)/sizeof(struct dbl_limits);
285 			i++, lim++) {
286 			if ((id.mantissa2 == lim->ieee.mantissa2) &&
287 				(id.mantissa1 == lim->ieee.mantissa1) &&
288 				(id.exp == lim->ieee.exp)) {
289 				vd = lim->d;
290 				goto doneit;
291 			}
292 		}
293 		vd.exp = id.exp - IEEE_DBL_BIAS + VAX_DBL_BIAS;
294 		vd.mantissa1 = (id.mantissa1 >> 13);
295 		vd.mantissa2 = ((id.mantissa1 & MASK(13)) << 3) |
296 				(id.mantissa2 >> 29);
297 		vd.mantissa3 = (id.mantissa2 >> 13);
298 		vd.mantissa4 = (id.mantissa2 << 3);
299 	doneit:
300 		vd.sign = id.sign;
301 		*dp = *((double *)&vd);
302 		return (TRUE);
303 #endif
304 
305 	case XDR_FREE:
306 		return (TRUE);
307 	}
308 	/* NOTREACHED */
309 	return (FALSE);
310 }
311