xref: /openbsd-src/lib/libc/rpc/xdr_float.c (revision daf88648c0e349d5c02e1504293082072c981640)
1 /*	$OpenBSD: xdr_float.c,v 1.16 2006/10/10 22:03:21 miod Exp $ */
2 /*
3  * Sun RPC is a product of Sun Microsystems, Inc. and is provided for
4  * unrestricted use provided that this legend is included on all tape
5  * media and as a part of the software program in whole or part.  Users
6  * may copy or modify Sun RPC without charge, but are not authorized
7  * to license or distribute it to anyone else except as part of a product or
8  * program developed by the user.
9  *
10  * SUN RPC IS PROVIDED AS IS WITH NO WARRANTIES OF ANY KIND INCLUDING THE
11  * WARRANTIES OF DESIGN, MERCHANTIBILITY AND FITNESS FOR A PARTICULAR
12  * PURPOSE, OR ARISING FROM A COURSE OF DEALING, USAGE OR TRADE PRACTICE.
13  *
14  * Sun RPC is provided with no support and without any obligation on the
15  * part of Sun Microsystems, Inc. to assist in its use, correction,
16  * modification or enhancement.
17  *
18  * SUN MICROSYSTEMS, INC. SHALL HAVE NO LIABILITY WITH RESPECT TO THE
19  * INFRINGEMENT OF COPYRIGHTS, TRADE SECRETS OR ANY PATENTS BY SUN RPC
20  * OR ANY PART THEREOF.
21  *
22  * In no event will Sun Microsystems, Inc. be liable for any lost revenue
23  * or profits or other special, indirect and consequential damages, even if
24  * Sun has been advised of the possibility of such damages.
25  *
26  * Sun Microsystems, Inc.
27  * 2550 Garcia Avenue
28  * Mountain View, California  94043
29  */
30 
31 /*
32  * xdr_float.c, Generic XDR routines implementation.
33  *
34  * Copyright (C) 1984, Sun Microsystems, Inc.
35  *
36  * These are the "floating point" xdr routines used to (de)serialize
37  * most common data items.  See xdr.h for more info on the interface to
38  * xdr.
39  */
40 
41 #include <stdio.h>
42 #include <sys/types.h>
43 #include <sys/param.h>
44 #include <rpc/types.h>
45 #include <rpc/xdr.h>
46 
47 /*
48  * NB: Not portable.
49  * This routine works on machines with IEEE754 FP and Vaxen.
50  */
51 
52 #if defined(__m68k__) || defined(__sparc__) || defined(__i386__) || \
53     defined(__mips__) || defined(__ns32k__) || defined(__alpha__) || \
54     defined(__arm__) || defined(__powerpc__) || defined(__m88k__) || \
55     defined(__hppa__) || defined(__x86_64__) || defined(__sh__)
56 #include <machine/endian.h>
57 #define IEEEFP
58 #endif
59 
60 #ifdef __vax__
61 
62 /* What IEEE single precision floating point looks like on a Vax */
63 struct	ieee_single {
64 	unsigned int	mantissa: 23;
65 	unsigned int	exp     : 8;
66 	unsigned int	sign    : 1;
67 };
68 
69 /* Vax single precision floating point */
70 struct	vax_single {
71 	unsigned int	mantissa1 : 7;
72 	unsigned int	exp       : 8;
73 	unsigned int	sign      : 1;
74 	unsigned int	mantissa2 : 16;
75 };
76 
77 #define VAX_SNG_BIAS	0x81
78 #define IEEE_SNG_BIAS	0x7f
79 
80 static struct sgl_limits {
81 	struct vax_single s;
82 	struct ieee_single ieee;
83 } sgl_limits[2] = {
84 	{{ 0x7f, 0xff, 0x0, 0xffff },	/* Max Vax */
85 	{ 0x0, 0xff, 0x0 }},		/* Max IEEE */
86 	{{ 0x0, 0x0, 0x0, 0x0 },	/* Min Vax */
87 	{ 0x0, 0x0, 0x0 }}		/* Min IEEE */
88 };
89 #endif /* __vax__ */
90 
91 bool_t
92 xdr_float(XDR *xdrs, float *fp)
93 {
94 #ifdef IEEEFP
95 	bool_t rv;
96 	long tmpl;
97 #else
98 	struct ieee_single is;
99 	struct vax_single vs, *vsp;
100 	struct sgl_limits *lim;
101 	int i;
102 #endif
103 	switch (xdrs->x_op) {
104 
105 	case XDR_ENCODE:
106 #ifdef IEEEFP
107 		tmpl = *(int32_t *)fp;
108 		return (XDR_PUTLONG(xdrs, &tmpl));
109 #else
110 		vs = *((struct vax_single *)fp);
111 		for (i = 0, lim = sgl_limits;
112 			i < sizeof(sgl_limits)/sizeof(struct sgl_limits);
113 			i++, lim++) {
114 			if ((vs.mantissa2 == lim->s.mantissa2) &&
115 				(vs.exp == lim->s.exp) &&
116 				(vs.mantissa1 == lim->s.mantissa1)) {
117 				is = lim->ieee;
118 				goto shipit;
119 			}
120 		}
121 		is.exp = vs.exp - VAX_SNG_BIAS + IEEE_SNG_BIAS;
122 		is.mantissa = (vs.mantissa1 << 16) | vs.mantissa2;
123 	shipit:
124 		is.sign = vs.sign;
125 		return (XDR_PUTLONG(xdrs, (long *)&is));
126 #endif
127 
128 	case XDR_DECODE:
129 #ifdef IEEEFP
130 		rv = XDR_GETLONG(xdrs, &tmpl);
131 		*(int32_t *)fp = tmpl;
132 		return (rv);
133 #else
134 		vsp = (struct vax_single *)fp;
135 		if (!XDR_GETLONG(xdrs, (long *)&is))
136 			return (FALSE);
137 		for (i = 0, lim = sgl_limits;
138 			i < sizeof(sgl_limits)/sizeof(struct 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 	return (FALSE);
158 }
159 
160 #ifdef __vax__
161 /* What IEEE double precision floating point looks like on a Vax */
162 struct	ieee_double {
163 	unsigned int	mantissa1 : 20;
164 	unsigned int	exp       : 11;
165 	unsigned int	sign      : 1;
166 	unsigned int	mantissa2 : 32;
167 };
168 
169 /* Vax double precision floating point */
170 struct  vax_double {
171 	unsigned int	mantissa1 : 7;
172 	unsigned int	exp       : 8;
173 	unsigned int	sign      : 1;
174 	unsigned int	mantissa2 : 16;
175 	unsigned int	mantissa3 : 16;
176 	unsigned int	mantissa4 : 16;
177 };
178 
179 #define VAX_DBL_BIAS	0x81
180 #define IEEE_DBL_BIAS	0x3ff
181 #define MASK(nbits)	((1 << nbits) - 1)
182 
183 static struct dbl_limits {
184 	struct	vax_double d;
185 	struct	ieee_double ieee;
186 } dbl_limits[2] = {
187 	{{ 0x7f, 0xff, 0x0, 0xffff, 0xffff, 0xffff },	/* Max Vax */
188 	{ 0x0, 0x7ff, 0x0, 0x0 }},			/* Max IEEE */
189 	{{ 0x0, 0x0, 0x0, 0x0, 0x0, 0x0},		/* Min Vax */
190 	{ 0x0, 0x0, 0x0, 0x0 }}				/* Min IEEE */
191 };
192 
193 #endif /* __vax__ */
194 
195 
196 bool_t
197 xdr_double(XDR *xdrs, double *dp)
198 {
199 #ifdef IEEEFP
200 	int32_t *i32p;
201 	bool_t rv;
202 	long tmpl;
203 #else
204 	long *lp;
205 	struct	ieee_double id;
206 	struct	vax_double vd;
207 	struct dbl_limits *lim;
208 	int i;
209 #endif
210 
211 	switch (xdrs->x_op) {
212 
213 	case XDR_ENCODE:
214 #ifdef IEEEFP
215 		i32p = (int32_t *)dp;
216 #if BYTE_ORDER == BIG_ENDIAN
217 		tmpl = *i32p++;
218 		rv = XDR_PUTLONG(xdrs, &tmpl);
219 		if (!rv)
220 			return (rv);
221 		tmpl = *i32p;
222 		rv = XDR_PUTLONG(xdrs, &tmpl);
223 #else
224 		tmpl = *(i32p+1);
225 		rv = XDR_PUTLONG(xdrs, &tmpl);
226 		if (!rv)
227 			return (rv);
228 		tmpl = *i32p;
229 		rv = XDR_PUTLONG(xdrs, &tmpl);
230 #endif
231 		return (rv);
232 #else
233 		vd = *((struct vax_double *)dp);
234 		for (i = 0, lim = dbl_limits;
235 			i < sizeof(dbl_limits)/sizeof(struct dbl_limits);
236 			i++, lim++) {
237 			if ((vd.mantissa4 == lim->d.mantissa4) &&
238 				(vd.mantissa3 == lim->d.mantissa3) &&
239 				(vd.mantissa2 == lim->d.mantissa2) &&
240 				(vd.mantissa1 == lim->d.mantissa1) &&
241 				(vd.exp == lim->d.exp)) {
242 				id = lim->ieee;
243 				goto shipit;
244 			}
245 		}
246 		id.exp = vd.exp - VAX_DBL_BIAS + IEEE_DBL_BIAS;
247 		id.mantissa1 = (vd.mantissa1 << 13) | (vd.mantissa2 >> 3);
248 		id.mantissa2 = ((vd.mantissa2 & MASK(3)) << 29) |
249 				(vd.mantissa3 << 13) |
250 				((vd.mantissa4 >> 3) & MASK(13));
251 	shipit:
252 		id.sign = vd.sign;
253 		lp = (long *)&id;
254 		return (XDR_PUTLONG(xdrs, lp++) && XDR_PUTLONG(xdrs, lp));
255 #endif
256 
257 	case XDR_DECODE:
258 #ifdef IEEEFP
259 		i32p = (int32_t *)dp;
260 #if BYTE_ORDER == BIG_ENDIAN
261 		rv = XDR_GETLONG(xdrs, &tmpl);
262 		*i32p++ = tmpl;
263 		if (!rv)
264 			return (rv);
265 		rv = XDR_GETLONG(xdrs, &tmpl);
266 		*i32p = tmpl;
267 #else
268 		rv = XDR_GETLONG(xdrs, &tmpl);
269 		*(i32p+1) = tmpl;
270 		if (!rv)
271 			return (rv);
272 		rv = XDR_GETLONG(xdrs, &tmpl);
273 		*i32p = tmpl;
274 #endif
275 		return (rv);
276 #else
277 		lp = (long *)&id;
278 		if (!XDR_GETLONG(xdrs, lp++) || !XDR_GETLONG(xdrs, lp))
279 			return (FALSE);
280 		for (i = 0, lim = dbl_limits;
281 			i < sizeof(dbl_limits)/sizeof(struct dbl_limits);
282 			i++, lim++) {
283 			if ((id.mantissa2 == lim->ieee.mantissa2) &&
284 				(id.mantissa1 == lim->ieee.mantissa1) &&
285 				(id.exp == lim->ieee.exp)) {
286 				vd = lim->d;
287 				goto doneit;
288 			}
289 		}
290 		vd.exp = id.exp - IEEE_DBL_BIAS + VAX_DBL_BIAS;
291 		vd.mantissa1 = (id.mantissa1 >> 13);
292 		vd.mantissa2 = ((id.mantissa1 & MASK(13)) << 3) |
293 				(id.mantissa2 >> 29);
294 		vd.mantissa3 = (id.mantissa2 >> 13);
295 		vd.mantissa4 = (id.mantissa2 << 3);
296 	doneit:
297 		vd.sign = id.sign;
298 		*dp = *((double *)&vd);
299 		return (TRUE);
300 #endif
301 
302 	case XDR_FREE:
303 		return (TRUE);
304 	}
305 	return (FALSE);
306 }
307