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/projects/cubeos/src_current/net/rpc/xdr_float.c

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/* @(#)xdr_float.c      2.1 88/07/29 4.0 RPCSRC */
/*
 * Sun RPC is a product of Sun Microsystems, Inc. and is provided for
 * unrestricted use provided that this legend is included on all tape
 * media and as a part of the software program in whole or part.  Users
 * may copy or modify Sun RPC without charge, but are not authorized
 * to license or distribute it to anyone else except as part of a product or
 * program developed by the user.
 * 
 * SUN RPC IS PROVIDED AS IS WITH NO WARRANTIES OF ANY KIND INCLUDING THE
 * WARRANTIES OF DESIGN, MERCHANTIBILITY AND FITNESS FOR A PARTICULAR
 * PURPOSE, OR ARISING FROM A COURSE OF DEALING, USAGE OR TRADE PRACTICE.
 * 
 * Sun RPC is provided with no support and without any obligation on the
 * part of Sun Microsystems, Inc. to assist in its use, correction,
 * modification or enhancement.
 * 
 * SUN MICROSYSTEMS, INC. SHALL HAVE NO LIABILITY WITH RESPECT TO THE
 * INFRINGEMENT OF COPYRIGHTS, TRADE SECRETS OR ANY PATENTS BY SUN RPC
 * OR ANY PART THEREOF.
 * 
 * In no event will Sun Microsystems, Inc. be liable for any lost revenue
 * or profits or other special, indirect and consequential damages, even if
 * Sun has been advised of the possibility of such damages.
 * 
 * Sun Microsystems, Inc.
 * 2550 Garcia Avenue
 * Mountain View, California  94043
 */
#if !defined(lint) && defined(SCCSIDS)
static char sccsid[] = "@(#)xdr_float.c 1.12 87/08/11 Copyr 1984 Sun Micro";
#endif

/*
 * xdr_float.c, Generic XDR routines impelmentation.
 *
 * Copyright (C) 1984, Sun Microsystems, Inc.
 *
 * These are the "floating point" xdr routines used to (de)serialize
 * most common data items.  See xdr.h for more info on the interface to
 * xdr.
 */

#include <stdio.h>

#include <rpc/types.h>
#include <rpc/xdr.h>

/*
 * NB: Not portable.
 * This routine works on Suns (Sky / 68000's) and Vaxen.
 */

#ifdef vax

/* What IEEE single precision floating point looks like on a Vax */
struct ieee_single {
        unsigned int mantissa:23;
        unsigned int exp:8;
        unsigned int sign:1;
};

/* Vax single precision floating point */
struct vax_single {
        unsigned int mantissa1:7;
        unsigned int exp:8;
        unsigned int sign:1;
        unsigned int mantissa2:16;
};

#define VAX_SNG_BIAS    0x81
#define IEEE_SNG_BIAS   0x7f

static struct sgl_limits {
        struct vax_single s;
        struct ieee_single ieee;
} sgl_limits[2] = {

        { {
                        0x7f, 0xff, 0x0, 0xffff
        },                      /* Max Vax */
        {
                0x0, 0xff, 0x0
        }
        },                      /* Max IEEE */
        { {
                        0x0, 0x0, 0x0, 0x0
        },                      /* Min Vax */
        {
                0x0, 0x0, 0x0
        }
        }                       /* Min IEEE */
};

#endif /* vax */

bool_t
xdr_float (xdrs, fp)
     register XDR *xdrs;
     register float *fp;
{
#if !defined(mc68000) && !defined(sparc)
        struct ieee_single is;
        struct vax_single vs, *vsp;
        struct sgl_limits *lim;
        int i;
#endif
        switch (xdrs->x_op) {

        case XDR_ENCODE:
#if defined(mc68000) || defined(sparc)
                return (XDR_PUTLONG (xdrs, (long *) fp));
#else
                vs = *((struct vax_single *) fp);
                for (i = 0, lim = sgl_limits;
                     i < sizeof (sgl_limits) / sizeof (struct sgl_limits);
                     i++, lim++) {
                        if ((vs.mantissa2 == lim->s.mantissa2) &&
                            (vs.exp == lim->s.exp) &&
                            (vs.mantissa1 == lim->s.mantissa1)) {
                                is = lim->ieee;
                                goto shipit;
                        }
                }
                is.exp = vs.exp - VAX_SNG_BIAS + IEEE_SNG_BIAS;
                is.mantissa = (vs.mantissa1 << 16) | vs.mantissa2;
              shipit:
                is.sign = vs.sign;
                return (XDR_PUTLONG (xdrs, (long *) &is));
#endif

        case XDR_DECODE:
#if defined(mc68000) || defined(sparc)
                return (XDR_GETLONG (xdrs, (long *) fp));
#else
                vsp = (struct vax_single *) fp;
                if (!XDR_GETLONG (xdrs, (long *) &is))
                        return (FALSE);
                for (i = 0, lim = sgl_limits;
                     i < sizeof (sgl_limits) / sizeof (struct sgl_limits);
                     i++, lim++) {
                        if ((is.exp == lim->ieee.exp) &&
                            (is.mantissa == lim->ieee.mantissa)) {
                                *vsp = lim->s;
                                goto doneit;
                        }
                }
                vsp->exp = is.exp - IEEE_SNG_BIAS + VAX_SNG_BIAS;
                vsp->mantissa2 = is.mantissa;
                vsp->mantissa1 = (is.mantissa >> 16);
              doneit:
                vsp->sign = is.sign;
                return (TRUE);
#endif

        case XDR_FREE:
                return (TRUE);
        }
        return (FALSE);
}

/*
 * This routine works on Suns (Sky / 68000's) and Vaxen.
 */

#ifdef vax
/* What IEEE double precision floating point looks like on a Vax */
struct ieee_double {
        unsigned int mantissa1:20;
        unsigned int exp:11;
        unsigned int sign:1;
        unsigned int mantissa2:32;
};

/* Vax double precision floating point */
struct vax_double {
        unsigned int mantissa1:7;
        unsigned int exp:8;
        unsigned int sign:1;
        unsigned int mantissa2:16;
        unsigned int mantissa3:16;
        unsigned int mantissa4:16;
};

#define VAX_DBL_BIAS    0x81
#define IEEE_DBL_BIAS   0x3ff
#define MASK(nbits)     ((1 << nbits) - 1)

static struct dbl_limits {
        struct vax_double d;
        struct ieee_double ieee;
} dbl_limits[2] = {

        { {
                        0x7f, 0xff, 0x0, 0xffff, 0xffff, 0xffff
        },                      /* Max Vax */
        {
                0x0, 0x7ff, 0x0, 0x0
        }
        },                      /* Max IEEE */
        { {
                        0x0, 0x0, 0x0, 0x0, 0x0, 0x0
        },                      /* Min Vax */
        {
                0x0, 0x0, 0x0, 0x0
        }
        }                       /* Min IEEE */
};

#endif /* vax */


bool_t
xdr_double (xdrs, dp)
     register XDR *xdrs;
     double *dp;
{
        register long *lp;
#if !defined(mc68000) && !defined(sparc)
        struct ieee_double id;
        struct vax_double vd;
        register struct dbl_limits *lim;
        int i;
#endif

        switch (xdrs->x_op) {

        case XDR_ENCODE:
#if defined(mc68000) || defined(sparc)
                lp = (long *) dp;
#else
                vd = *((struct vax_double *) dp);
                for (i = 0, lim = dbl_limits;
                     i < sizeof (dbl_limits) / sizeof (struct dbl_limits);
                     i++, lim++) {
                        if ((vd.mantissa4 == lim->d.mantissa4) &&
                            (vd.mantissa3 == lim->d.mantissa3) &&
                            (vd.mantissa2 == lim->d.mantissa2) &&
                            (vd.mantissa1 == lim->d.mantissa1) &&
                            (vd.exp == lim->d.exp)) {
                                id = lim->ieee;
                                goto shipit;
                        }
                }
                id.exp = vd.exp - VAX_DBL_BIAS + IEEE_DBL_BIAS;
                id.mantissa1 = (vd.mantissa1 << 13) | (vd.mantissa2 >> 3);
                id.mantissa2 = ((vd.mantissa2 & MASK (3)) << 29) |
                        (vd.mantissa3 << 13) |
                        ((vd.mantissa4 >> 3) & MASK (13));
              shipit:
                id.sign = vd.sign;
                lp = (long *) &id;
#endif
                return (XDR_PUTLONG (xdrs, lp++) && XDR_PUTLONG (xdrs, lp));

        case XDR_DECODE:
#if defined(mc68000) || defined(sparc)
                lp = (long *) dp;
                return (XDR_GETLONG (xdrs, lp++) && XDR_GETLONG (xdrs, lp));
#else
                lp = (long *) &id;
                if (!XDR_GETLONG (xdrs, lp++) || !XDR_GETLONG (xdrs, lp))
                        return (FALSE);
                for (i = 0, lim = dbl_limits;
                     i < sizeof (dbl_limits) / sizeof (struct dbl_limits);
                     i++, lim++) {
                        if ((id.mantissa2 == lim->ieee.mantissa2) &&
                            (id.mantissa1 == lim->ieee.mantissa1) &&
                            (id.exp == lim->ieee.exp)) {
                                vd = lim->d;
                                goto doneit;
                        }
                }
                vd.exp = id.exp - IEEE_DBL_BIAS + VAX_DBL_BIAS;
                vd.mantissa1 = (id.mantissa1 >> 13);
                vd.mantissa2 = ((id.mantissa1 & MASK (13)) << 3) |
                        (id.mantissa2 >> 29);
                vd.mantissa3 = (id.mantissa2 >> 13);
                vd.mantissa4 = (id.mantissa2 << 3);
              doneit:
                vd.sign = id.sign;
                *dp = *((double *) &vd);
                return (TRUE);
#endif

        case XDR_FREE:
                return (TRUE);
        }
        return (FALSE);
}

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