xref: /freebsd/lib/libc/xdr/xdr_float.c (revision 0c43d89a0d8e976ca494d4837f4c1f3734d2c300)
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 = "$Id: xdr_float.c,v 1.1 1993/10/27 05:41:10 paul Exp $";
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 Suns (Sky / 68000's), i386's, MIPS, NS32k and Vaxen.
55  */
56 
57 #if defined(mc68000)||defined(sparc)||defined(i386)||defined(mips)||defined(ns32000)
58 #define IEEEFP
59 #endif
60 
61 #ifdef vax
62 
63 /* What IEEE single precision floating point looks like on a Vax */
64 struct	ieee_single {
65 	unsigned int	mantissa: 23;
66 	unsigned int	exp     : 8;
67 	unsigned int	sign    : 1;
68 };
69 
70 /* Vax single precision floating point */
71 struct	vax_single {
72 	unsigned int	mantissa1 : 7;
73 	unsigned int	exp       : 8;
74 	unsigned int	sign      : 1;
75 	unsigned int	mantissa2 : 16;
76 };
77 
78 #define VAX_SNG_BIAS	0x81
79 #define IEEE_SNG_BIAS	0x7f
80 
81 static struct sgl_limits {
82 	struct vax_single s;
83 	struct ieee_single ieee;
84 } sgl_limits[2] = {
85 	{{ 0x7f, 0xff, 0x0, 0xffff },	/* Max Vax */
86 	{ 0x0, 0xff, 0x0 }},		/* Max IEEE */
87 	{{ 0x0, 0x0, 0x0, 0x0 },	/* Min Vax */
88 	{ 0x0, 0x0, 0x0 }}		/* Min IEEE */
89 };
90 #endif /* vax */
91 
92 bool_t
93 xdr_float(xdrs, fp)
94 	register XDR *xdrs;
95 	register float *fp;
96 {
97 #ifndef IEEEFP
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 		return (XDR_PUTLONG(xdrs, (long *)fp));
108 #else
109 		vs = *((struct vax_single *)fp);
110 		for (i = 0, lim = sgl_limits;
111 			i < sizeof(sgl_limits)/sizeof(struct sgl_limits);
112 			i++, lim++) {
113 			if ((vs.mantissa2 == lim->s.mantissa2) &&
114 				(vs.exp == lim->s.exp) &&
115 				(vs.mantissa1 == lim->s.mantissa1)) {
116 				is = lim->ieee;
117 				goto shipit;
118 			}
119 		}
120 		is.exp = vs.exp - VAX_SNG_BIAS + IEEE_SNG_BIAS;
121 		is.mantissa = (vs.mantissa1 << 16) | vs.mantissa2;
122 	shipit:
123 		is.sign = vs.sign;
124 		return (XDR_PUTLONG(xdrs, (long *)&is));
125 #endif
126 
127 	case XDR_DECODE:
128 #ifdef IEEEFP
129 		return (XDR_GETLONG(xdrs, (long *)fp));
130 #else
131 		vsp = (struct vax_single *)fp;
132 		if (!XDR_GETLONG(xdrs, (long *)&is))
133 			return (FALSE);
134 		for (i = 0, lim = sgl_limits;
135 			i < sizeof(sgl_limits)/sizeof(struct sgl_limits);
136 			i++, lim++) {
137 			if ((is.exp == lim->ieee.exp) &&
138 				(is.mantissa == lim->ieee.mantissa)) {
139 				*vsp = lim->s;
140 				goto doneit;
141 			}
142 		}
143 		vsp->exp = is.exp - IEEE_SNG_BIAS + VAX_SNG_BIAS;
144 		vsp->mantissa2 = is.mantissa;
145 		vsp->mantissa1 = (is.mantissa >> 16);
146 	doneit:
147 		vsp->sign = is.sign;
148 		return (TRUE);
149 #endif
150 
151 	case XDR_FREE:
152 		return (TRUE);
153 	}
154 	return (FALSE);
155 }
156 
157 /*
158  * This routine works on Suns (Sky / 68000's), i386's, MIPS and Vaxen.
159  */
160 
161 #ifdef vax
162 /* What IEEE double precision floating point looks like on a Vax */
163 struct	ieee_double {
164 	unsigned int	mantissa1 : 20;
165 	unsigned int	exp       : 11;
166 	unsigned int	sign      : 1;
167 	unsigned int	mantissa2 : 32;
168 };
169 
170 /* Vax double precision floating point */
171 struct  vax_double {
172 	unsigned int	mantissa1 : 7;
173 	unsigned int	exp       : 8;
174 	unsigned int	sign      : 1;
175 	unsigned int	mantissa2 : 16;
176 	unsigned int	mantissa3 : 16;
177 	unsigned int	mantissa4 : 16;
178 };
179 
180 #define VAX_DBL_BIAS	0x81
181 #define IEEE_DBL_BIAS	0x3ff
182 #define MASK(nbits)	((1 << nbits) - 1)
183 
184 static struct dbl_limits {
185 	struct	vax_double d;
186 	struct	ieee_double ieee;
187 } dbl_limits[2] = {
188 	{{ 0x7f, 0xff, 0x0, 0xffff, 0xffff, 0xffff },	/* Max Vax */
189 	{ 0x0, 0x7ff, 0x0, 0x0 }},			/* Max IEEE */
190 	{{ 0x0, 0x0, 0x0, 0x0, 0x0, 0x0},		/* Min Vax */
191 	{ 0x0, 0x0, 0x0, 0x0 }}				/* Min IEEE */
192 };
193 
194 #endif /* vax */
195 
196 
197 bool_t
198 xdr_double(xdrs, dp)
199 	register XDR *xdrs;
200 	double *dp;
201 {
202 	register long *lp;
203 #ifndef IEEEFP
204 	struct	ieee_double id;
205 	struct	vax_double vd;
206 	register struct dbl_limits *lim;
207 	int i;
208 #endif
209 
210 	switch (xdrs->x_op) {
211 
212 	case XDR_ENCODE:
213 #ifdef IEEEFP
214 		lp = (long *)dp;
215 #if BYTE_ORDER == BIG_ENDIAN
216 		return (XDR_PUTLONG(xdrs, lp++) && XDR_PUTLONG(xdrs, lp));
217 #else
218 		return (XDR_PUTLONG(xdrs, lp+1) && XDR_PUTLONG(xdrs, lp));
219 #endif
220 #else
221 		vd = *((struct vax_double *)dp);
222 		for (i = 0, lim = dbl_limits;
223 			i < sizeof(dbl_limits)/sizeof(struct dbl_limits);
224 			i++, lim++) {
225 			if ((vd.mantissa4 == lim->d.mantissa4) &&
226 				(vd.mantissa3 == lim->d.mantissa3) &&
227 				(vd.mantissa2 == lim->d.mantissa2) &&
228 				(vd.mantissa1 == lim->d.mantissa1) &&
229 				(vd.exp == lim->d.exp)) {
230 				id = lim->ieee;
231 				goto shipit;
232 			}
233 		}
234 		id.exp = vd.exp - VAX_DBL_BIAS + IEEE_DBL_BIAS;
235 		id.mantissa1 = (vd.mantissa1 << 13) | (vd.mantissa2 >> 3);
236 		id.mantissa2 = ((vd.mantissa2 & MASK(3)) << 29) |
237 				(vd.mantissa3 << 13) |
238 				((vd.mantissa4 >> 3) & MASK(13));
239 	shipit:
240 		id.sign = vd.sign;
241 		lp = (long *)&id;
242 		return (XDR_PUTLONG(xdrs, lp++) && XDR_PUTLONG(xdrs, lp));
243 #endif
244 
245 	case XDR_DECODE:
246 #ifdef IEEEFP
247 		lp = (long *)dp;
248 #if BYTE_ORDER == BIG_ENDIAN
249 		return (XDR_GETLONG(xdrs, lp++) && XDR_GETLONG(xdrs, lp));
250 #else
251 		return (XDR_GETLONG(xdrs, lp+1) && XDR_GETLONG(xdrs, lp));
252 #endif
253 #else
254 		lp = (long *)&id;
255 		if (!XDR_GETLONG(xdrs, lp++) || !XDR_GETLONG(xdrs, lp))
256 			return (FALSE);
257 		for (i = 0, lim = dbl_limits;
258 			i < sizeof(dbl_limits)/sizeof(struct dbl_limits);
259 			i++, lim++) {
260 			if ((id.mantissa2 == lim->ieee.mantissa2) &&
261 				(id.mantissa1 == lim->ieee.mantissa1) &&
262 				(id.exp == lim->ieee.exp)) {
263 				vd = lim->d;
264 				goto doneit;
265 			}
266 		}
267 		vd.exp = id.exp - IEEE_DBL_BIAS + VAX_DBL_BIAS;
268 		vd.mantissa1 = (id.mantissa1 >> 13);
269 		vd.mantissa2 = ((id.mantissa1 & MASK(13)) << 3) |
270 				(id.mantissa2 >> 29);
271 		vd.mantissa3 = (id.mantissa2 >> 13);
272 		vd.mantissa4 = (id.mantissa2 << 3);
273 	doneit:
274 		vd.sign = id.sign;
275 		*dp = *((double *)&vd);
276 		return (TRUE);
277 #endif
278 
279 	case XDR_FREE:
280 		return (TRUE);
281 	}
282 	return (FALSE);
283 }
284