xref: /netbsd-src/lib/libc/rpc/xdr_float.c (revision 201fac6e3d8ac6a5503c4810b0378f73101d50c3)
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 1.3 1994/12/04 01:13:39 cgd 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  * Sparcs, and Alphas
56  */
57 
58 #if defined(mc68000)||defined(sparc)||defined(i386)||defined(mips)||defined(ns32k)||defined(alpha)
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 #ifndef IEEEFP
99 	struct ieee_single is;
100 	struct vax_single vs, *vsp;
101 	struct sgl_limits *lim;
102 	int i;
103 #endif
104 	switch (xdrs->x_op) {
105 
106 	case XDR_ENCODE:
107 #ifdef IEEEFP
108 		return (XDR_PUTLONG(xdrs, (long *)fp));
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 		return (XDR_GETLONG(xdrs, (long *)fp));
131 #else
132 		vsp = (struct vax_single *)fp;
133 		if (!XDR_GETLONG(xdrs, (long *)&is))
134 			return (FALSE);
135 		for (i = 0, lim = sgl_limits;
136 			i < sizeof(sgl_limits)/sizeof(struct sgl_limits);
137 			i++, lim++) {
138 			if ((is.exp == lim->ieee.exp) &&
139 				(is.mantissa == lim->ieee.mantissa)) {
140 				*vsp = lim->s;
141 				goto doneit;
142 			}
143 		}
144 		vsp->exp = is.exp - IEEE_SNG_BIAS + VAX_SNG_BIAS;
145 		vsp->mantissa2 = is.mantissa;
146 		vsp->mantissa1 = (is.mantissa >> 16);
147 	doneit:
148 		vsp->sign = is.sign;
149 		return (TRUE);
150 #endif
151 
152 	case XDR_FREE:
153 		return (TRUE);
154 	}
155 	return (FALSE);
156 }
157 
158 /*
159  * This routine works on Suns (Sky / 68000's), i386's, MIPS and Vaxen.
160  */
161 
162 #ifdef vax
163 /* What IEEE double precision floating point looks like on a Vax */
164 struct	ieee_double {
165 	unsigned int	mantissa1 : 20;
166 	unsigned int	exp       : 11;
167 	unsigned int	sign      : 1;
168 	unsigned int	mantissa2 : 32;
169 };
170 
171 /* Vax double precision floating point */
172 struct  vax_double {
173 	unsigned int	mantissa1 : 7;
174 	unsigned int	exp       : 8;
175 	unsigned int	sign      : 1;
176 	unsigned int	mantissa2 : 16;
177 	unsigned int	mantissa3 : 16;
178 	unsigned int	mantissa4 : 16;
179 };
180 
181 #define VAX_DBL_BIAS	0x81
182 #define IEEE_DBL_BIAS	0x3ff
183 #define MASK(nbits)	((1 << nbits) - 1)
184 
185 static struct dbl_limits {
186 	struct	vax_double d;
187 	struct	ieee_double ieee;
188 } dbl_limits[2] = {
189 	{{ 0x7f, 0xff, 0x0, 0xffff, 0xffff, 0xffff },	/* Max Vax */
190 	{ 0x0, 0x7ff, 0x0, 0x0 }},			/* Max IEEE */
191 	{{ 0x0, 0x0, 0x0, 0x0, 0x0, 0x0},		/* Min Vax */
192 	{ 0x0, 0x0, 0x0, 0x0 }}				/* Min IEEE */
193 };
194 
195 #endif /* vax */
196 
197 
198 bool_t
199 xdr_double(xdrs, dp)
200 	register XDR *xdrs;
201 	double *dp;
202 {
203 	register long *lp;
204 #ifndef IEEEFP
205 	struct	ieee_double id;
206 	struct	vax_double vd;
207 	register struct dbl_limits *lim;
208 	int i;
209 #endif
210 
211 	switch (xdrs->x_op) {
212 
213 	case XDR_ENCODE:
214 #ifdef IEEEFP
215 		lp = (long *)dp;
216 #if BYTE_ORDER == BIG_ENDIAN
217 		return (XDR_PUTLONG(xdrs, lp++) && XDR_PUTLONG(xdrs, lp));
218 #else
219 		return (XDR_PUTLONG(xdrs, lp+1) && XDR_PUTLONG(xdrs, lp));
220 #endif
221 #else
222 		vd = *((struct vax_double *)dp);
223 		for (i = 0, lim = dbl_limits;
224 			i < sizeof(dbl_limits)/sizeof(struct dbl_limits);
225 			i++, lim++) {
226 			if ((vd.mantissa4 == lim->d.mantissa4) &&
227 				(vd.mantissa3 == lim->d.mantissa3) &&
228 				(vd.mantissa2 == lim->d.mantissa2) &&
229 				(vd.mantissa1 == lim->d.mantissa1) &&
230 				(vd.exp == lim->d.exp)) {
231 				id = lim->ieee;
232 				goto shipit;
233 			}
234 		}
235 		id.exp = vd.exp - VAX_DBL_BIAS + IEEE_DBL_BIAS;
236 		id.mantissa1 = (vd.mantissa1 << 13) | (vd.mantissa2 >> 3);
237 		id.mantissa2 = ((vd.mantissa2 & MASK(3)) << 29) |
238 				(vd.mantissa3 << 13) |
239 				((vd.mantissa4 >> 3) & MASK(13));
240 	shipit:
241 		id.sign = vd.sign;
242 		lp = (long *)&id;
243 		return (XDR_PUTLONG(xdrs, lp++) && XDR_PUTLONG(xdrs, lp));
244 #endif
245 
246 	case XDR_DECODE:
247 #ifdef IEEEFP
248 		lp = (long *)dp;
249 #if BYTE_ORDER == BIG_ENDIAN
250 		return (XDR_GETLONG(xdrs, lp++) && XDR_GETLONG(xdrs, lp));
251 #else
252 		return (XDR_GETLONG(xdrs, lp+1) && XDR_GETLONG(xdrs, lp));
253 #endif
254 #else
255 		lp = (long *)&id;
256 		if (!XDR_GETLONG(xdrs, lp++) || !XDR_GETLONG(xdrs, lp))
257 			return (FALSE);
258 		for (i = 0, lim = dbl_limits;
259 			i < sizeof(dbl_limits)/sizeof(struct dbl_limits);
260 			i++, lim++) {
261 			if ((id.mantissa2 == lim->ieee.mantissa2) &&
262 				(id.mantissa1 == lim->ieee.mantissa1) &&
263 				(id.exp == lim->ieee.exp)) {
264 				vd = lim->d;
265 				goto doneit;
266 			}
267 		}
268 		vd.exp = id.exp - IEEE_DBL_BIAS + VAX_DBL_BIAS;
269 		vd.mantissa1 = (id.mantissa1 >> 13);
270 		vd.mantissa2 = ((id.mantissa1 & MASK(13)) << 3) |
271 				(id.mantissa2 >> 29);
272 		vd.mantissa3 = (id.mantissa2 >> 13);
273 		vd.mantissa4 = (id.mantissa2 << 3);
274 	doneit:
275 		vd.sign = id.sign;
276 		*dp = *((double *)&vd);
277 		return (TRUE);
278 #endif
279 
280 	case XDR_FREE:
281 		return (TRUE);
282 	}
283 	return (FALSE);
284 }
285