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      1 /*	$NetBSD: xdr_float.c,v 1.42 2024/04/11 18:41:03 christos Exp $	*/
      2 
      3 /*
      4  * Copyright (c) 2010, Oracle America, Inc.
      5  *
      6  * Redistribution and use in source and binary forms, with or without
      7  * modification, are permitted provided that the following conditions are
      8  * met:
      9  *
     10  *     * Redistributions of source code must retain the above copyright
     11  *       notice, this list of conditions and the following disclaimer.
     12  *     * Redistributions in binary form must reproduce the above
     13  *       copyright notice, this list of conditions and the following
     14  *       disclaimer in the documentation and/or other materials
     15  *       provided with the distribution.
     16  *     * Neither the name of the "Oracle America, Inc." nor the names of its
     17  *       contributors may be used to endorse or promote products derived
     18  *       from this software without specific prior written permission.
     19  *
     20  *   THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
     21  *   "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
     22  *   LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
     23  *   FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
     24  *   COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT,
     25  *   INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
     26  *   DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE
     27  *   GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
     28  *   INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
     29  *   WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
     30  *   NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
     31  *   OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
     32  */
     33 
     34 #include <sys/cdefs.h>
     35 #if defined(LIBC_SCCS) && !defined(lint)
     36 #if 0
     37 static char *sccsid = "@(#)xdr_float.c 1.12 87/08/11 Copyr 1984 Sun Micro";
     38 static char *sccsid = "@(#)xdr_float.c	2.1 88/07/29 4.0 RPCSRC";
     39 #else
     40 __RCSID("$NetBSD: xdr_float.c,v 1.42 2024/04/11 18:41:03 christos Exp $");
     41 #endif
     42 #endif
     43 
     44 /*
     45  * xdr_float.c, Generic XDR routines implementation.
     46  *
     47  * Copyright (C) 1984, Sun Microsystems, Inc.
     48  *
     49  * These are the "floating point" xdr routines used to (de)serialize
     50  * most common data items.  See xdr.h for more info on the interface to
     51  * xdr.
     52  */
     53 
     54 #include "namespace.h"
     55 
     56 #include <sys/types.h>
     57 #include <sys/param.h>
     58 
     59 #include <stdio.h>
     60 #include <string.h>
     61 
     62 #include <rpc/types.h>
     63 #include <rpc/xdr.h>
     64 
     65 #ifdef __weak_alias
     66 __weak_alias(xdr_double,_xdr_double)
     67 __weak_alias(xdr_float,_xdr_float)
     68 #endif
     69 
     70 /*
     71  * NB: Not portable.
     72  * This routine works on machines with IEEE754 FP and Vaxen.
     73  */
     74 
     75 #if !defined(__vax__)
     76 #include <machine/endian.h>
     77 #define IEEEFP
     78 #endif
     79 
     80 #if defined(__vax__)
     81 
     82 /* What IEEE single precision floating point looks like on a Vax */
     83 struct	ieee_single {
     84 	unsigned int	mantissa: 23;
     85 	unsigned int	exp     : 8;
     86 	unsigned int	sign    : 1;
     87 };
     88 
     89 /* Vax single precision floating point */
     90 struct	vax_single {
     91 	unsigned int	mantissa1 : 7;
     92 	unsigned int	exp       : 8;
     93 	unsigned int	sign      : 1;
     94 	unsigned int	mantissa2 : 16;
     95 };
     96 
     97 #define VAX_SNG_BIAS	0x81
     98 #define IEEE_SNG_BIAS	0x7f
     99 
    100 static struct sgl_limits {
    101 	struct vax_single s;
    102 	struct ieee_single ieee;
    103 } sgl_limits[2] = {
    104 	{{ 0x7f, 0xff, 0x0, 0xffff },	/* Max Vax */
    105 	{ 0x0, 0xff, 0x0 }},		/* Max IEEE */
    106 	{{ 0x0, 0x0, 0x0, 0x0 },	/* Min Vax */
    107 	{ 0x0, 0x0, 0x0 }}		/* Min IEEE */
    108 };
    109 #endif /* vax */
    110 
    111 bool_t
    112 xdr_float(XDR *xdrs, float *fp)
    113 {
    114 #ifndef IEEEFP
    115 	struct ieee_single is;
    116 	struct vax_single vs, *vsp;
    117 	struct sgl_limits *lim;
    118 	size_t i;
    119 #endif
    120 	switch (xdrs->x_op) {
    121 
    122 	case XDR_ENCODE:
    123 #ifdef IEEEFP
    124 		return (XDR_PUTINT32(xdrs, (int32_t *)(void *)fp));
    125 #else
    126 		vs = *((struct vax_single *)(void *)fp);
    127 		for (i = 0, lim = sgl_limits;
    128 			i < sizeof(sgl_limits)/sizeof(struct sgl_limits);
    129 			i++, lim++) {
    130 			if ((vs.mantissa2 == lim->s.mantissa2) &&
    131 				(vs.exp == lim->s.exp) &&
    132 				(vs.mantissa1 == lim->s.mantissa1)) {
    133 				is = lim->ieee;
    134 				goto shipit;
    135 			}
    136 		}
    137 		is.exp = vs.exp - VAX_SNG_BIAS + IEEE_SNG_BIAS;
    138 		is.mantissa = (vs.mantissa1 << 16) | vs.mantissa2;
    139 	shipit:
    140 		is.sign = vs.sign;
    141 		return (XDR_PUTINT32(xdrs, (int32_t *)(void *)&is));
    142 #endif
    143 
    144 	case XDR_DECODE:
    145 #ifdef IEEEFP
    146 		return (XDR_GETINT32(xdrs, (int32_t *)(void *)fp));
    147 #else
    148 		vsp = (struct vax_single *)(void *)fp;
    149 		if (!XDR_GETINT32(xdrs, (int32_t *)(void *)&is))
    150 			return (FALSE);
    151 		for (i = 0, lim = sgl_limits;
    152 			i < sizeof(sgl_limits)/sizeof(struct sgl_limits);
    153 			i++, lim++) {
    154 			if ((is.exp == lim->ieee.exp) &&
    155 				(is.mantissa == lim->ieee.mantissa)) {
    156 				*vsp = lim->s;
    157 				goto doneit;
    158 			}
    159 		}
    160 		vsp->exp = is.exp - IEEE_SNG_BIAS + VAX_SNG_BIAS;
    161 		vsp->mantissa2 = is.mantissa;
    162 		vsp->mantissa1 = ((unsigned int)is.mantissa >> 16);
    163 	doneit:
    164 		vsp->sign = is.sign;
    165 		return (TRUE);
    166 #endif
    167 
    168 	case XDR_FREE:
    169 		return (TRUE);
    170 	}
    171 	/* NOTREACHED */
    172 	return (FALSE);
    173 }
    174 
    175 #if defined(__vax__)
    176 /* What IEEE double precision floating point looks like on a Vax */
    177 struct	ieee_double {
    178 	unsigned int	mantissa1 : 20;
    179 	unsigned int	exp       : 11;
    180 	unsigned int	sign      : 1;
    181 	unsigned int	mantissa2 : 32;
    182 };
    183 
    184 /* Vax double precision floating point */
    185 struct  vax_double {
    186 	unsigned int	mantissa1 : 7;
    187 	unsigned int	exp       : 8;
    188 	unsigned int	sign      : 1;
    189 	unsigned int	mantissa2 : 16;
    190 	unsigned int	mantissa3 : 16;
    191 	unsigned int	mantissa4 : 16;
    192 };
    193 
    194 #define VAX_DBL_BIAS	0x81
    195 #define IEEE_DBL_BIAS	0x3ff
    196 #define MASK(nbits)	((1 << nbits) - 1)
    197 
    198 static struct dbl_limits {
    199 	struct	vax_double d;
    200 	struct	ieee_double ieee;
    201 } dbl_limits[2] = {
    202 	{{ 0x7f, 0xff, 0x0, 0xffff, 0xffff, 0xffff },	/* Max Vax */
    203 	{ 0x0, 0x7ff, 0x0, 0x0 }},			/* Max IEEE */
    204 	{{ 0x0, 0x0, 0x0, 0x0, 0x0, 0x0},		/* Min Vax */
    205 	{ 0x0, 0x0, 0x0, 0x0 }}				/* Min IEEE */
    206 };
    207 
    208 #endif /* vax */
    209 
    210 
    211 bool_t
    212 xdr_double(XDR *xdrs, double *dp)
    213 {
    214 #ifdef IEEEFP
    215 	int32_t *i32p;
    216 	bool_t rv;
    217 #else
    218 	int32_t *lp;
    219 	struct	ieee_double id;
    220 	struct	vax_double vd;
    221 	struct dbl_limits *lim;
    222 	size_t i;
    223 #endif
    224 
    225 	switch (xdrs->x_op) {
    226 
    227 	case XDR_ENCODE:
    228 #ifdef IEEEFP
    229 		i32p = (int32_t *)(void *)dp;
    230 #if (BYTE_ORDER == BIG_ENDIAN) || \
    231     (defined(__arm__) && !defined(__VFP_FP__))
    232 		rv = XDR_PUTINT32(xdrs, i32p);
    233 		if (!rv)
    234 			return (rv);
    235 		rv = XDR_PUTINT32(xdrs, i32p+1);
    236 #else
    237 		rv = XDR_PUTINT32(xdrs, i32p+1);
    238 		if (!rv)
    239 			return (rv);
    240 		rv = XDR_PUTINT32(xdrs, i32p);
    241 #endif
    242 		return (rv);
    243 #else
    244 		vd = *((struct vax_double *)(void *)dp);
    245 		for (i = 0, lim = dbl_limits;
    246 			i < sizeof(dbl_limits)/sizeof(struct dbl_limits);
    247 			i++, lim++) {
    248 			if ((vd.mantissa4 == lim->d.mantissa4) &&
    249 				(vd.mantissa3 == lim->d.mantissa3) &&
    250 				(vd.mantissa2 == lim->d.mantissa2) &&
    251 				(vd.mantissa1 == lim->d.mantissa1) &&
    252 				(vd.exp == lim->d.exp)) {
    253 				id = lim->ieee;
    254 				goto shipit;
    255 			}
    256 		}
    257 		/*LINTED: possible overflow*/
    258 		id.exp = vd.exp - VAX_DBL_BIAS + IEEE_DBL_BIAS;
    259 		id.mantissa1 = (vd.mantissa1 << 13) |
    260 			    ((unsigned int)vd.mantissa2 >> 3);
    261 		id.mantissa2 = ((vd.mantissa2 & MASK(3)) << 29) |
    262 				(vd.mantissa3 << 13) |
    263 				(((unsigned int)vd.mantissa4 >> 3) & MASK(13));
    264 	shipit:
    265 		id.sign = vd.sign;
    266 		lp = (int32_t *)(void *)&id;
    267 		return (XDR_PUTINT32(xdrs, lp++) && XDR_PUTINT32(xdrs, lp));
    268 #endif
    269 
    270 	case XDR_DECODE:
    271 #ifdef IEEEFP
    272 		i32p = (int32_t *)(void *)dp;
    273 #if BYTE_ORDER == BIG_ENDIAN || \
    274     (defined(__arm__) && !defined(__VFP_FP__))
    275 		rv = XDR_GETINT32(xdrs, i32p);
    276 		if (!rv)
    277 			return (rv);
    278 		rv = XDR_GETINT32(xdrs, i32p+1);
    279 #else
    280 		rv = XDR_GETINT32(xdrs, i32p+1);
    281 		if (!rv)
    282 			return (rv);
    283 		rv = XDR_GETINT32(xdrs, i32p);
    284 #endif
    285 		return (rv);
    286 #else
    287 		lp = (int32_t *)(void *)&id;
    288 		if (!XDR_GETINT32(xdrs, lp++) || !XDR_GETINT32(xdrs, lp))
    289 			return (FALSE);
    290 		for (i = 0, lim = dbl_limits;
    291 			i < sizeof(dbl_limits)/sizeof(struct dbl_limits);
    292 			i++, lim++) {
    293 			if ((id.mantissa2 == lim->ieee.mantissa2) &&
    294 				(id.mantissa1 == lim->ieee.mantissa1) &&
    295 				(id.exp == lim->ieee.exp)) {
    296 				vd = lim->d;
    297 				goto doneit;
    298 			}
    299 		}
    300 		/*LINTED: can overflow */
    301 		vd.exp = id.exp - IEEE_DBL_BIAS + VAX_DBL_BIAS;
    302 		vd.mantissa1 = ((unsigned int)id.mantissa1 >> 13);
    303 		vd.mantissa2 = ((id.mantissa1 & MASK(13)) << 3) |
    304 				((unsigned int)id.mantissa2 >> 29);
    305 		vd.mantissa3 = ((unsigned int)id.mantissa2 >> 13);
    306 		vd.mantissa4 = (id.mantissa2 << 3);
    307 	doneit:
    308 		vd.sign = id.sign;
    309 		memcpy(dp, &vd, sizeof(double));
    310 		return (TRUE);
    311 #endif
    312 
    313 	case XDR_FREE:
    314 		return (TRUE);
    315 	}
    316 	/* NOTREACHED */
    317 	return (FALSE);
    318 }
    319