xref: /dragonfly/lib/libc/xdr/xdr_float.c (revision 57fed2af)
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.
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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  * @(#)xdr_float.c 1.12 87/08/11 Copyr 1984 Sun Micro
30  * @(#)xdr_float.c	2.1 88/07/29 4.0 RPCSRC
31  * $FreeBSD: src/lib/libc/xdr/xdr_float.c,v 1.7 1999/08/28 00:02:55 peter Exp $
32  * $DragonFly: src/lib/libc/xdr/xdr_float.c,v 1.3 2004/10/25 19:38:02 drhodus Exp $
33  */
34 
35 /*
36  * xdr_float.c, Generic XDR routines impelmentation.
37  *
38  * Copyright (C) 1984, Sun Microsystems, Inc.
39  *
40  * These are the "floating point" xdr routines used to (de)serialize
41  * most common data items.  See xdr.h for more info on the interface to
42  * xdr.
43  */
44 
45 #include <stdio.h>
46 #include <sys/types.h>
47 #include <sys/param.h>
48 #include <rpc/types.h>
49 #include <rpc/xdr.h>
50 
51 /*
52  * NB: Not portable.
53  * This routine works on machines with IEEE754 FP and Vaxen.
54  */
55 
56 #if defined(__m68k__) || defined(__sparc__) || defined(__i386__) || \
57     defined(__mips__) || defined(__ns32k__) || defined(__alpha__) || \
58     defined(__arm32__) || defined(__ppc__)
59 #include <machine/endian.h>
60 #define IEEEFP
61 #endif
62 
63 #ifdef vax
64 
65 /* What IEEE single precision floating point looks like on a Vax */
66 struct	ieee_single {
67 	unsigned int	mantissa: 23;
68 	unsigned int	exp     : 8;
69 	unsigned int	sign    : 1;
70 };
71 
72 /* Vax single precision floating point */
73 struct	vax_single {
74 	unsigned int	mantissa1 : 7;
75 	unsigned int	exp       : 8;
76 	unsigned int	sign      : 1;
77 	unsigned int	mantissa2 : 16;
78 };
79 
80 #define VAX_SNG_BIAS	0x81
81 #define IEEE_SNG_BIAS	0x7f
82 
83 static struct sgl_limits {
84 	struct vax_single s;
85 	struct ieee_single ieee;
86 } sgl_limits[2] = {
87 	{{ 0x7f, 0xff, 0x0, 0xffff },	/* Max Vax */
88 	{ 0x0, 0xff, 0x0 }},		/* Max IEEE */
89 	{{ 0x0, 0x0, 0x0, 0x0 },	/* Min Vax */
90 	{ 0x0, 0x0, 0x0 }}		/* Min IEEE */
91 };
92 #endif /* vax */
93 
94 bool_t
95 xdr_float(xdrs, fp)
96 	XDR *xdrs;
97 	float *fp;
98 {
99 #ifdef IEEEFP
100 	bool_t rv;
101 	long tmpl;
102 #else
103 	struct ieee_single is;
104 	struct vax_single vs, *vsp;
105 	struct sgl_limits *lim;
106 	int i;
107 #endif
108 	switch (xdrs->x_op) {
109 
110 	case XDR_ENCODE:
111 #ifdef IEEEFP
112 		tmpl = *(int32_t *)fp;
113 		return (XDR_PUTLONG(xdrs, &tmpl));
114 #else
115 		vs = *((struct vax_single *)fp);
116 		for (i = 0, lim = sgl_limits;
117 			i < sizeof(sgl_limits)/sizeof(struct sgl_limits);
118 			i++, lim++) {
119 			if ((vs.mantissa2 == lim->s.mantissa2) &&
120 				(vs.exp == lim->s.exp) &&
121 				(vs.mantissa1 == lim->s.mantissa1)) {
122 				is = lim->ieee;
123 				goto shipit;
124 			}
125 		}
126 		is.exp = vs.exp - VAX_SNG_BIAS + IEEE_SNG_BIAS;
127 		is.mantissa = (vs.mantissa1 << 16) | vs.mantissa2;
128 	shipit:
129 		is.sign = vs.sign;
130 		return (XDR_PUTLONG(xdrs, (long *)&is));
131 #endif
132 
133 	case XDR_DECODE:
134 #ifdef IEEEFP
135 		rv = XDR_GETLONG(xdrs, &tmpl);
136 		*(int32_t *)fp = tmpl;
137 		return (rv);
138 #else
139 		vsp = (struct vax_single *)fp;
140 		if (!XDR_GETLONG(xdrs, (long *)&is))
141 			return (FALSE);
142 		for (i = 0, lim = sgl_limits;
143 			i < sizeof(sgl_limits)/sizeof(struct sgl_limits);
144 			i++, lim++) {
145 			if ((is.exp == lim->ieee.exp) &&
146 				(is.mantissa == lim->ieee.mantissa)) {
147 				*vsp = lim->s;
148 				goto doneit;
149 			}
150 		}
151 		vsp->exp = is.exp - IEEE_SNG_BIAS + VAX_SNG_BIAS;
152 		vsp->mantissa2 = is.mantissa;
153 		vsp->mantissa1 = (is.mantissa >> 16);
154 	doneit:
155 		vsp->sign = is.sign;
156 		return (TRUE);
157 #endif
158 
159 	case XDR_FREE:
160 		return (TRUE);
161 	}
162 	return (FALSE);
163 }
164 
165 #ifdef vax
166 /* What IEEE double precision floating point looks like on a Vax */
167 struct	ieee_double {
168 	unsigned int	mantissa1 : 20;
169 	unsigned int	exp       : 11;
170 	unsigned int	sign      : 1;
171 	unsigned int	mantissa2 : 32;
172 };
173 
174 /* Vax double precision floating point */
175 struct  vax_double {
176 	unsigned int	mantissa1 : 7;
177 	unsigned int	exp       : 8;
178 	unsigned int	sign      : 1;
179 	unsigned int	mantissa2 : 16;
180 	unsigned int	mantissa3 : 16;
181 	unsigned int	mantissa4 : 16;
182 };
183 
184 #define VAX_DBL_BIAS	0x81
185 #define IEEE_DBL_BIAS	0x3ff
186 #define MASK(nbits)	((1 << nbits) - 1)
187 
188 static struct dbl_limits {
189 	struct	vax_double d;
190 	struct	ieee_double ieee;
191 } dbl_limits[2] = {
192 	{{ 0x7f, 0xff, 0x0, 0xffff, 0xffff, 0xffff },	/* Max Vax */
193 	{ 0x0, 0x7ff, 0x0, 0x0 }},			/* Max IEEE */
194 	{{ 0x0, 0x0, 0x0, 0x0, 0x0, 0x0},		/* Min Vax */
195 	{ 0x0, 0x0, 0x0, 0x0 }}				/* Min IEEE */
196 };
197 
198 #endif /* vax */
199 
200 
201 bool_t
202 xdr_double(xdrs, dp)
203 	XDR *xdrs;
204 	double *dp;
205 {
206 #ifdef IEEEFP
207 	int32_t *i32p;
208 	bool_t rv;
209 	long tmpl;
210 #else
211 	long *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 *)dp;
223 #if BYTE_ORDER == BIG_ENDIAN
224 		tmpl = *i32p++;
225 		rv = XDR_PUTLONG(xdrs, &tmpl);
226 		if (!rv)
227 			return (rv);
228 		tmpl = *i32p;
229 		rv = XDR_PUTLONG(xdrs, &tmpl);
230 #else
231 		tmpl = *(i32p+1);
232 		rv = XDR_PUTLONG(xdrs, &tmpl);
233 		if (!rv)
234 			return (rv);
235 		tmpl = *i32p;
236 		rv = XDR_PUTLONG(xdrs, &tmpl);
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 = (long *)&id;
261 		return (XDR_PUTLONG(xdrs, lp++) && XDR_PUTLONG(xdrs, lp));
262 #endif
263 
264 	case XDR_DECODE:
265 #ifdef IEEEFP
266 		i32p = (int32_t *)dp;
267 #if BYTE_ORDER == BIG_ENDIAN
268 		rv = XDR_GETLONG(xdrs, &tmpl);
269 		*i32p++ = tmpl;
270 		if (!rv)
271 			return (rv);
272 		rv = XDR_GETLONG(xdrs, &tmpl);
273 		*i32p = tmpl;
274 #else
275 		rv = XDR_GETLONG(xdrs, &tmpl);
276 		*(i32p+1) = tmpl;
277 		if (!rv)
278 			return (rv);
279 		rv = XDR_GETLONG(xdrs, &tmpl);
280 		*i32p = tmpl;
281 #endif
282 		return (rv);
283 #else
284 		lp = (long *)&id;
285 		if (!XDR_GETLONG(xdrs, lp++) || !XDR_GETLONG(xdrs, lp))
286 			return (FALSE);
287 		for (i = 0, lim = dbl_limits;
288 			i < sizeof(dbl_limits)/sizeof(struct dbl_limits);
289 			i++, lim++) {
290 			if ((id.mantissa2 == lim->ieee.mantissa2) &&
291 				(id.mantissa1 == lim->ieee.mantissa1) &&
292 				(id.exp == lim->ieee.exp)) {
293 				vd = lim->d;
294 				goto doneit;
295 			}
296 		}
297 		vd.exp = id.exp - IEEE_DBL_BIAS + VAX_DBL_BIAS;
298 		vd.mantissa1 = (id.mantissa1 >> 13);
299 		vd.mantissa2 = ((id.mantissa1 & MASK(13)) << 3) |
300 				(id.mantissa2 >> 29);
301 		vd.mantissa3 = (id.mantissa2 >> 13);
302 		vd.mantissa4 = (id.mantissa2 << 3);
303 	doneit:
304 		vd.sign = id.sign;
305 		*dp = *((double *)&vd);
306 		return (TRUE);
307 #endif
308 
309 	case XDR_FREE:
310 		return (TRUE);
311 	}
312 	return (FALSE);
313 }
314