xref: /openbsd-src/lib/libc/rpc/xdr_float.c (revision a4afd6dad3fba28f80e70208181c06c482259988)
1 /*
2  * Sun RPC is a product of Sun Microsystems, Inc. and is provided for
3  * unrestricted use provided that this legend is included on all tape
4  * media and as a part of the software program in whole or part.  Users
5  * may copy or modify Sun RPC without charge, but are not authorized
6  * to license or distribute it to anyone else except as part of a product or
7  * program developed by the user.
8  *
9  * SUN RPC IS PROVIDED AS IS WITH NO WARRANTIES OF ANY KIND INCLUDING THE
10  * WARRANTIES OF DESIGN, MERCHANTIBILITY AND FITNESS FOR A PARTICULAR
11  * PURPOSE, OR ARISING FROM A COURSE OF DEALING, USAGE OR TRADE PRACTICE.
12  *
13  * Sun RPC is provided with no support and without any obligation on the
14  * part of Sun Microsystems, Inc. to assist in its use, correction,
15  * modification or enhancement.
16  *
17  * SUN MICROSYSTEMS, INC. SHALL HAVE NO LIABILITY WITH RESPECT TO THE
18  * INFRINGEMENT OF COPYRIGHTS, TRADE SECRETS OR ANY PATENTS BY SUN RPC
19  * OR ANY PART THEREOF.
20  *
21  * In no event will Sun Microsystems, Inc. be liable for any lost revenue
22  * or profits or other special, indirect and consequential damages, even if
23  * Sun has been advised of the possibility of such damages.
24  *
25  * Sun Microsystems, Inc.
26  * 2550 Garcia Avenue
27  * Mountain View, California  94043
28  */
29 
30 #if defined(LIBC_SCCS) && !defined(lint)
31 static char *rcsid = "$OpenBSD: xdr_float.c,v 1.4 1996/08/19 08:32:03 tholo Exp $";
32 #endif /* LIBC_SCCS and not lint */
33 
34 /*
35  * xdr_float.c, Generic XDR routines impelmentation.
36  *
37  * Copyright (C) 1984, Sun Microsystems, Inc.
38  *
39  * These are the "floating point" xdr routines used to (de)serialize
40  * most common data items.  See xdr.h for more info on the interface to
41  * xdr.
42  */
43 
44 #include <stdio.h>
45 #include <sys/types.h>
46 #include <sys/param.h>
47 #include <rpc/types.h>
48 #include <rpc/xdr.h>
49 
50 /*
51  * NB: Not portable.
52  * This routine works on machines with IEEE754 FP and Vaxen.
53  */
54 
55 #if defined(__m68k__) || defined(__sparc__) || defined(__i386__) || \
56     defined(__mips__) || defined(__ns32k__) || defined(__alpha__) || \
57     defined(__arm32__)
58 #include <machine/endian.h>
59 #define IEEEFP
60 #endif
61 
62 #ifdef vax
63 
64 /* What IEEE single precision floating point looks like on a Vax */
65 struct	ieee_single {
66 	unsigned int	mantissa: 23;
67 	unsigned int	exp     : 8;
68 	unsigned int	sign    : 1;
69 };
70 
71 /* Vax single precision floating point */
72 struct	vax_single {
73 	unsigned int	mantissa1 : 7;
74 	unsigned int	exp       : 8;
75 	unsigned int	sign      : 1;
76 	unsigned int	mantissa2 : 16;
77 };
78 
79 #define VAX_SNG_BIAS	0x81
80 #define IEEE_SNG_BIAS	0x7f
81 
82 static struct sgl_limits {
83 	struct vax_single s;
84 	struct ieee_single ieee;
85 } sgl_limits[2] = {
86 	{{ 0x7f, 0xff, 0x0, 0xffff },	/* Max Vax */
87 	{ 0x0, 0xff, 0x0 }},		/* Max IEEE */
88 	{{ 0x0, 0x0, 0x0, 0x0 },	/* Min Vax */
89 	{ 0x0, 0x0, 0x0 }}		/* Min IEEE */
90 };
91 #endif /* vax */
92 
93 bool_t
94 xdr_float(xdrs, fp)
95 	register XDR *xdrs;
96 	register float *fp;
97 {
98 #ifdef IEEEFP
99 	bool_t rv;
100 	long tmpl;
101 #else
102 	struct ieee_single is;
103 	struct vax_single vs, *vsp;
104 	struct sgl_limits *lim;
105 	int i;
106 #endif
107 	switch (xdrs->x_op) {
108 
109 	case XDR_ENCODE:
110 #ifdef IEEEFP
111 		tmpl = *(int32_t *)fp;
112 		return (XDR_PUTLONG(xdrs, &tmpl));
113 #else
114 		vs = *((struct vax_single *)fp);
115 		for (i = 0, lim = sgl_limits;
116 			i < sizeof(sgl_limits)/sizeof(struct sgl_limits);
117 			i++, lim++) {
118 			if ((vs.mantissa2 == lim->s.mantissa2) &&
119 				(vs.exp == lim->s.exp) &&
120 				(vs.mantissa1 == lim->s.mantissa1)) {
121 				is = lim->ieee;
122 				goto shipit;
123 			}
124 		}
125 		is.exp = vs.exp - VAX_SNG_BIAS + IEEE_SNG_BIAS;
126 		is.mantissa = (vs.mantissa1 << 16) | vs.mantissa2;
127 	shipit:
128 		is.sign = vs.sign;
129 		return (XDR_PUTLONG(xdrs, (long *)&is));
130 #endif
131 
132 	case XDR_DECODE:
133 #ifdef IEEEFP
134 		rv = XDR_GETLONG(xdrs, &tmpl);
135 		*(int32_t *)fp = tmpl;
136 		return (rv);
137 #else
138 		vsp = (struct vax_single *)fp;
139 		if (!XDR_GETLONG(xdrs, (long *)&is))
140 			return (FALSE);
141 		for (i = 0, lim = sgl_limits;
142 			i < sizeof(sgl_limits)/sizeof(struct sgl_limits);
143 			i++, lim++) {
144 			if ((is.exp == lim->ieee.exp) &&
145 				(is.mantissa == lim->ieee.mantissa)) {
146 				*vsp = lim->s;
147 				goto doneit;
148 			}
149 		}
150 		vsp->exp = is.exp - IEEE_SNG_BIAS + VAX_SNG_BIAS;
151 		vsp->mantissa2 = is.mantissa;
152 		vsp->mantissa1 = (is.mantissa >> 16);
153 	doneit:
154 		vsp->sign = is.sign;
155 		return (TRUE);
156 #endif
157 
158 	case XDR_FREE:
159 		return (TRUE);
160 	}
161 	return (FALSE);
162 }
163 
164 #ifdef vax
165 /* What IEEE double precision floating point looks like on a Vax */
166 struct	ieee_double {
167 	unsigned int	mantissa1 : 20;
168 	unsigned int	exp       : 11;
169 	unsigned int	sign      : 1;
170 	unsigned int	mantissa2 : 32;
171 };
172 
173 /* Vax double precision floating point */
174 struct  vax_double {
175 	unsigned int	mantissa1 : 7;
176 	unsigned int	exp       : 8;
177 	unsigned int	sign      : 1;
178 	unsigned int	mantissa2 : 16;
179 	unsigned int	mantissa3 : 16;
180 	unsigned int	mantissa4 : 16;
181 };
182 
183 #define VAX_DBL_BIAS	0x81
184 #define IEEE_DBL_BIAS	0x3ff
185 #define MASK(nbits)	((1 << nbits) - 1)
186 
187 static struct dbl_limits {
188 	struct	vax_double d;
189 	struct	ieee_double ieee;
190 } dbl_limits[2] = {
191 	{{ 0x7f, 0xff, 0x0, 0xffff, 0xffff, 0xffff },	/* Max Vax */
192 	{ 0x0, 0x7ff, 0x0, 0x0 }},			/* Max IEEE */
193 	{{ 0x0, 0x0, 0x0, 0x0, 0x0, 0x0},		/* Min Vax */
194 	{ 0x0, 0x0, 0x0, 0x0 }}				/* Min IEEE */
195 };
196 
197 #endif /* vax */
198 
199 
200 bool_t
201 xdr_double(xdrs, dp)
202 	register XDR *xdrs;
203 	double *dp;
204 {
205 #ifdef IEEEFP
206 	register int32_t *i32p;
207 	bool_t rv;
208 	long tmpl;
209 #else
210 	register long *lp;
211 	struct	ieee_double id;
212 	struct	vax_double vd;
213 	register struct dbl_limits *lim;
214 	int i;
215 #endif
216 
217 	switch (xdrs->x_op) {
218 
219 	case XDR_ENCODE:
220 #ifdef IEEEFP
221 		i32p = (int32_t *)dp;
222 #if BYTE_ORDER == BIG_ENDIAN
223 		tmpl = *i32p++;
224 		rv = XDR_PUTLONG(xdrs, &tmpl);
225 		if (!rv)
226 			return (rv);
227 		tmpl = *i32p;
228 		rv = XDR_PUTLONG(xdrs, &tmpl);
229 #else
230 		tmpl = *(i32p+1);
231 		rv = XDR_PUTLONG(xdrs, &tmpl);
232 		if (!rv)
233 			return (rv);
234 		tmpl = *i32p;
235 		rv = XDR_PUTLONG(xdrs, &tmpl);
236 #endif
237 		return (rv);
238 #else
239 		vd = *((struct vax_double *)dp);
240 		for (i = 0, lim = dbl_limits;
241 			i < sizeof(dbl_limits)/sizeof(struct dbl_limits);
242 			i++, lim++) {
243 			if ((vd.mantissa4 == lim->d.mantissa4) &&
244 				(vd.mantissa3 == lim->d.mantissa3) &&
245 				(vd.mantissa2 == lim->d.mantissa2) &&
246 				(vd.mantissa1 == lim->d.mantissa1) &&
247 				(vd.exp == lim->d.exp)) {
248 				id = lim->ieee;
249 				goto shipit;
250 			}
251 		}
252 		id.exp = vd.exp - VAX_DBL_BIAS + IEEE_DBL_BIAS;
253 		id.mantissa1 = (vd.mantissa1 << 13) | (vd.mantissa2 >> 3);
254 		id.mantissa2 = ((vd.mantissa2 & MASK(3)) << 29) |
255 				(vd.mantissa3 << 13) |
256 				((vd.mantissa4 >> 3) & MASK(13));
257 	shipit:
258 		id.sign = vd.sign;
259 		lp = (long *)&id;
260 		return (XDR_PUTLONG(xdrs, lp++) && XDR_PUTLONG(xdrs, lp));
261 #endif
262 
263 	case XDR_DECODE:
264 #ifdef IEEEFP
265 		i32p = (int32_t *)dp;
266 #if BYTE_ORDER == BIG_ENDIAN
267 		rv = XDR_GETLONG(xdrs, &tmpl);
268 		*i32p++ = tmpl;
269 		if (!rv)
270 			return (rv);
271 		rv = XDR_GETLONG(xdrs, &tmpl);
272 		*i32p = tmpl;
273 #else
274 		rv = XDR_GETLONG(xdrs, &tmpl);
275 		*(i32p+1) = tmpl;
276 		if (!rv)
277 			return (rv);
278 		rv = XDR_GETLONG(xdrs, &tmpl);
279 		*i32p = tmpl;
280 #endif
281 		return (rv);
282 #else
283 		lp = (long *)&id;
284 		if (!XDR_GETLONG(xdrs, lp++) || !XDR_GETLONG(xdrs, lp))
285 			return (FALSE);
286 		for (i = 0, lim = dbl_limits;
287 			i < sizeof(dbl_limits)/sizeof(struct dbl_limits);
288 			i++, lim++) {
289 			if ((id.mantissa2 == lim->ieee.mantissa2) &&
290 				(id.mantissa1 == lim->ieee.mantissa1) &&
291 				(id.exp == lim->ieee.exp)) {
292 				vd = lim->d;
293 				goto doneit;
294 			}
295 		}
296 		vd.exp = id.exp - IEEE_DBL_BIAS + VAX_DBL_BIAS;
297 		vd.mantissa1 = (id.mantissa1 >> 13);
298 		vd.mantissa2 = ((id.mantissa1 & MASK(13)) << 3) |
299 				(id.mantissa2 >> 29);
300 		vd.mantissa3 = (id.mantissa2 >> 13);
301 		vd.mantissa4 = (id.mantissa2 << 3);
302 	doneit:
303 		vd.sign = id.sign;
304 		*dp = *((double *)&vd);
305 		return (TRUE);
306 #endif
307 
308 	case XDR_FREE:
309 		return (TRUE);
310 	}
311 	return (FALSE);
312 }
313