xref: /freebsd/lib/libc/xdr/xdr_float.c (revision c3aac50f284c6cca5b4f2eb46aaa13812cb8b630)
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 *sccsid = "from: @(#)xdr_float.c 1.12 87/08/11 Copyr 1984 Sun Micro";*/
32 /*static char *sccsid = "from: @(#)xdr_float.c	2.1 88/07/29 4.0 RPCSRC";*/
33 static char *rcsid = "$FreeBSD$";
34 #endif
35 
36 /*
37  * xdr_float.c, Generic XDR routines impelmentation.
38  *
39  * Copyright (C) 1984, Sun Microsystems, Inc.
40  *
41  * These are the "floating point" xdr routines used to (de)serialize
42  * most common data items.  See xdr.h for more info on the interface to
43  * xdr.
44  */
45 
46 #include <stdio.h>
47 #include <sys/types.h>
48 #include <sys/param.h>
49 #include <rpc/types.h>
50 #include <rpc/xdr.h>
51 
52 /*
53  * NB: Not portable.
54  * This routine works on machines with IEEE754 FP and Vaxen.
55  */
56 
57 #if defined(__m68k__) || defined(__sparc__) || defined(__i386__) || \
58     defined(__mips__) || defined(__ns32k__) || defined(__alpha__) || \
59     defined(__arm32__) || defined(__ppc__)
60 #include <machine/endian.h>
61 #define IEEEFP
62 #endif
63 
64 #ifdef vax
65 
66 /* What IEEE single precision floating point looks like on a Vax */
67 struct	ieee_single {
68 	unsigned int	mantissa: 23;
69 	unsigned int	exp     : 8;
70 	unsigned int	sign    : 1;
71 };
72 
73 /* Vax single precision floating point */
74 struct	vax_single {
75 	unsigned int	mantissa1 : 7;
76 	unsigned int	exp       : 8;
77 	unsigned int	sign      : 1;
78 	unsigned int	mantissa2 : 16;
79 };
80 
81 #define VAX_SNG_BIAS	0x81
82 #define IEEE_SNG_BIAS	0x7f
83 
84 static struct sgl_limits {
85 	struct vax_single s;
86 	struct ieee_single ieee;
87 } sgl_limits[2] = {
88 	{{ 0x7f, 0xff, 0x0, 0xffff },	/* Max Vax */
89 	{ 0x0, 0xff, 0x0 }},		/* Max IEEE */
90 	{{ 0x0, 0x0, 0x0, 0x0 },	/* Min Vax */
91 	{ 0x0, 0x0, 0x0 }}		/* Min IEEE */
92 };
93 #endif /* vax */
94 
95 bool_t
96 xdr_float(xdrs, fp)
97 	register XDR *xdrs;
98 	register float *fp;
99 {
100 #ifdef IEEEFP
101 	bool_t rv;
102 	long tmpl;
103 #else
104 	struct ieee_single is;
105 	struct vax_single vs, *vsp;
106 	struct sgl_limits *lim;
107 	int i;
108 #endif
109 	switch (xdrs->x_op) {
110 
111 	case XDR_ENCODE:
112 #ifdef IEEEFP
113 		tmpl = *(int32_t *)fp;
114 		return (XDR_PUTLONG(xdrs, &tmpl));
115 #else
116 		vs = *((struct vax_single *)fp);
117 		for (i = 0, lim = sgl_limits;
118 			i < sizeof(sgl_limits)/sizeof(struct sgl_limits);
119 			i++, lim++) {
120 			if ((vs.mantissa2 == lim->s.mantissa2) &&
121 				(vs.exp == lim->s.exp) &&
122 				(vs.mantissa1 == lim->s.mantissa1)) {
123 				is = lim->ieee;
124 				goto shipit;
125 			}
126 		}
127 		is.exp = vs.exp - VAX_SNG_BIAS + IEEE_SNG_BIAS;
128 		is.mantissa = (vs.mantissa1 << 16) | vs.mantissa2;
129 	shipit:
130 		is.sign = vs.sign;
131 		return (XDR_PUTLONG(xdrs, (long *)&is));
132 #endif
133 
134 	case XDR_DECODE:
135 #ifdef IEEEFP
136 		rv = XDR_GETLONG(xdrs, &tmpl);
137 		*(int32_t *)fp = tmpl;
138 		return (rv);
139 #else
140 		vsp = (struct vax_single *)fp;
141 		if (!XDR_GETLONG(xdrs, (long *)&is))
142 			return (FALSE);
143 		for (i = 0, lim = sgl_limits;
144 			i < sizeof(sgl_limits)/sizeof(struct sgl_limits);
145 			i++, lim++) {
146 			if ((is.exp == lim->ieee.exp) &&
147 				(is.mantissa == lim->ieee.mantissa)) {
148 				*vsp = lim->s;
149 				goto doneit;
150 			}
151 		}
152 		vsp->exp = is.exp - IEEE_SNG_BIAS + VAX_SNG_BIAS;
153 		vsp->mantissa2 = is.mantissa;
154 		vsp->mantissa1 = (is.mantissa >> 16);
155 	doneit:
156 		vsp->sign = is.sign;
157 		return (TRUE);
158 #endif
159 
160 	case XDR_FREE:
161 		return (TRUE);
162 	}
163 	return (FALSE);
164 }
165 
166 #ifdef vax
167 /* What IEEE double precision floating point looks like on a Vax */
168 struct	ieee_double {
169 	unsigned int	mantissa1 : 20;
170 	unsigned int	exp       : 11;
171 	unsigned int	sign      : 1;
172 	unsigned int	mantissa2 : 32;
173 };
174 
175 /* Vax double precision floating point */
176 struct  vax_double {
177 	unsigned int	mantissa1 : 7;
178 	unsigned int	exp       : 8;
179 	unsigned int	sign      : 1;
180 	unsigned int	mantissa2 : 16;
181 	unsigned int	mantissa3 : 16;
182 	unsigned int	mantissa4 : 16;
183 };
184 
185 #define VAX_DBL_BIAS	0x81
186 #define IEEE_DBL_BIAS	0x3ff
187 #define MASK(nbits)	((1 << nbits) - 1)
188 
189 static struct dbl_limits {
190 	struct	vax_double d;
191 	struct	ieee_double ieee;
192 } dbl_limits[2] = {
193 	{{ 0x7f, 0xff, 0x0, 0xffff, 0xffff, 0xffff },	/* Max Vax */
194 	{ 0x0, 0x7ff, 0x0, 0x0 }},			/* Max IEEE */
195 	{{ 0x0, 0x0, 0x0, 0x0, 0x0, 0x0},		/* Min Vax */
196 	{ 0x0, 0x0, 0x0, 0x0 }}				/* Min IEEE */
197 };
198 
199 #endif /* vax */
200 
201 
202 bool_t
203 xdr_double(xdrs, dp)
204 	register XDR *xdrs;
205 	double *dp;
206 {
207 #ifdef IEEEFP
208 	register int32_t *i32p;
209 	bool_t rv;
210 	long tmpl;
211 #else
212 	register long *lp;
213 	struct	ieee_double id;
214 	struct	vax_double vd;
215 	register struct dbl_limits *lim;
216 	int i;
217 #endif
218 
219 	switch (xdrs->x_op) {
220 
221 	case XDR_ENCODE:
222 #ifdef IEEEFP
223 		i32p = (int32_t *)dp;
224 #if BYTE_ORDER == BIG_ENDIAN
225 		tmpl = *i32p++;
226 		rv = XDR_PUTLONG(xdrs, &tmpl);
227 		if (!rv)
228 			return (rv);
229 		tmpl = *i32p;
230 		rv = XDR_PUTLONG(xdrs, &tmpl);
231 #else
232 		tmpl = *(i32p+1);
233 		rv = XDR_PUTLONG(xdrs, &tmpl);
234 		if (!rv)
235 			return (rv);
236 		tmpl = *i32p;
237 		rv = XDR_PUTLONG(xdrs, &tmpl);
238 #endif
239 		return (rv);
240 #else
241 		vd = *((struct vax_double *)dp);
242 		for (i = 0, lim = dbl_limits;
243 			i < sizeof(dbl_limits)/sizeof(struct dbl_limits);
244 			i++, lim++) {
245 			if ((vd.mantissa4 == lim->d.mantissa4) &&
246 				(vd.mantissa3 == lim->d.mantissa3) &&
247 				(vd.mantissa2 == lim->d.mantissa2) &&
248 				(vd.mantissa1 == lim->d.mantissa1) &&
249 				(vd.exp == lim->d.exp)) {
250 				id = lim->ieee;
251 				goto shipit;
252 			}
253 		}
254 		id.exp = vd.exp - VAX_DBL_BIAS + IEEE_DBL_BIAS;
255 		id.mantissa1 = (vd.mantissa1 << 13) | (vd.mantissa2 >> 3);
256 		id.mantissa2 = ((vd.mantissa2 & MASK(3)) << 29) |
257 				(vd.mantissa3 << 13) |
258 				((vd.mantissa4 >> 3) & MASK(13));
259 	shipit:
260 		id.sign = vd.sign;
261 		lp = (long *)&id;
262 		return (XDR_PUTLONG(xdrs, lp++) && XDR_PUTLONG(xdrs, lp));
263 #endif
264 
265 	case XDR_DECODE:
266 #ifdef IEEEFP
267 		i32p = (int32_t *)dp;
268 #if BYTE_ORDER == BIG_ENDIAN
269 		rv = XDR_GETLONG(xdrs, &tmpl);
270 		*i32p++ = tmpl;
271 		if (!rv)
272 			return (rv);
273 		rv = XDR_GETLONG(xdrs, &tmpl);
274 		*i32p = tmpl;
275 #else
276 		rv = XDR_GETLONG(xdrs, &tmpl);
277 		*(i32p+1) = tmpl;
278 		if (!rv)
279 			return (rv);
280 		rv = XDR_GETLONG(xdrs, &tmpl);
281 		*i32p = tmpl;
282 #endif
283 		return (rv);
284 #else
285 		lp = (long *)&id;
286 		if (!XDR_GETLONG(xdrs, lp++) || !XDR_GETLONG(xdrs, lp))
287 			return (FALSE);
288 		for (i = 0, lim = dbl_limits;
289 			i < sizeof(dbl_limits)/sizeof(struct dbl_limits);
290 			i++, lim++) {
291 			if ((id.mantissa2 == lim->ieee.mantissa2) &&
292 				(id.mantissa1 == lim->ieee.mantissa1) &&
293 				(id.exp == lim->ieee.exp)) {
294 				vd = lim->d;
295 				goto doneit;
296 			}
297 		}
298 		vd.exp = id.exp - IEEE_DBL_BIAS + VAX_DBL_BIAS;
299 		vd.mantissa1 = (id.mantissa1 >> 13);
300 		vd.mantissa2 = ((id.mantissa1 & MASK(13)) << 3) |
301 				(id.mantissa2 >> 29);
302 		vd.mantissa3 = (id.mantissa2 >> 13);
303 		vd.mantissa4 = (id.mantissa2 << 3);
304 	doneit:
305 		vd.sign = id.sign;
306 		*dp = *((double *)&vd);
307 		return (TRUE);
308 #endif
309 
310 	case XDR_FREE:
311 		return (TRUE);
312 	}
313 	return (FALSE);
314 }
315