/*      $NetBSD: xdr_float.c,v 1.23 2000/07/17 04:59:51 matt Exp $      */

/*-
 * SPDX-License-Identifier: BSD-3-Clause
 *
 * Copyright (c) 2010, Oracle America, Inc.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are
 * met:
 *
 *     * Redistributions of source code must retain the above copyright
 *       notice, this list of conditions and the following disclaimer.
 *     * Redistributions in binary form must reproduce the above
 *       copyright notice, this list of conditions and the following
 *       disclaimer in the documentation and/or other materials
 *       provided with the distribution.
 *     * Neither the name of the "Oracle America, Inc." nor the names of its
 *       contributors may be used to endorse or promote products derived
 *       from this software without specific prior written permission.
 *
 *   THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 *   "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
 *   LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
 *   FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
 *   COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT,
 *   INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 *   DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE
 *   GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
 *   INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
 *   WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
 *   NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
 *   OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */

/*
 * xdr_float.c, Generic XDR routines implementation.
 *
 * 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 "namespace.h"
#include <sys/param.h>

#include <stdio.h>

#include <rpc/types.h>
#include <rpc/xdr.h>
#include "un-namespace.h"

/*
 * NB: Not portable.
 * This routine works on machines with IEEE754 FP and Vaxen.
 */

#include <machine/endian.h>
#define IEEEFP

#if defined(__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(XDR *xdrs, float *fp)
{
#ifndef IEEEFP
        struct ieee_single is;
        struct vax_single vs, *vsp;
        struct sgl_limits *lim;
        u_int i;
#endif
        switch (xdrs->x_op) {

        case XDR_ENCODE:
#ifdef IEEEFP
                return (XDR_PUTINT32(xdrs, (int32_t *)fp));
#else
                vs = *((struct vax_single *)fp);
                for (i = 0, lim = sgl_limits; i < nitems(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_PUTINT32(xdrs, (int32_t *)&is));
#endif

        case XDR_DECODE:
#ifdef IEEEFP
                return (XDR_GETINT32(xdrs, (int32_t *)fp));
#else
                vsp = (struct vax_single *)fp;
                if (!XDR_GETINT32(xdrs, (int32_t *)&is))
                        return (FALSE);
                for (i = 0, lim = sgl_limits; i < nitems(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);
        }
        /* NOTREACHED */
        return (FALSE);
}

#if defined(__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(XDR *xdrs, double *dp)
{
#ifdef IEEEFP
        int32_t *i32p;
        bool_t rv;
#else
        int32_t *lp;
        struct  ieee_double id;
        struct  vax_double vd;
        struct dbl_limits *lim;
        u_int i;
#endif

        switch (xdrs->x_op) {

        case XDR_ENCODE:
#ifdef IEEEFP
                i32p = (int32_t *)(void *)dp;
#if BYTE_ORDER == BIG_ENDIAN
                rv = XDR_PUTINT32(xdrs, i32p);
                if (!rv)
                        return (rv);
                rv = XDR_PUTINT32(xdrs, i32p+1);
#else
                rv = XDR_PUTINT32(xdrs, i32p+1);
                if (!rv)
                        return (rv);
                rv = XDR_PUTINT32(xdrs, i32p);
#endif
                return (rv);
#else
                vd = *((struct vax_double *)dp);
                for (i = 0, lim = dbl_limits; i < nitems(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 = (int32_t *)&id;
                return (XDR_PUTINT32(xdrs, lp++) && XDR_PUTINT32(xdrs, lp));
#endif

        case XDR_DECODE:
#ifdef IEEEFP
                i32p = (int32_t *)(void *)dp;
#if BYTE_ORDER == BIG_ENDIAN
                rv = XDR_GETINT32(xdrs, i32p);
                if (!rv)
                        return (rv);
                rv = XDR_GETINT32(xdrs, i32p+1);
#else
                rv = XDR_GETINT32(xdrs, i32p+1);
                if (!rv)
                        return (rv);
                rv = XDR_GETINT32(xdrs, i32p);
#endif
                return (rv);
#else
                lp = (int32_t *)&id;
                if (!XDR_GETINT32(xdrs, lp++) || !XDR_GETINT32(xdrs, lp))
                        return (FALSE);
                for (i = 0, lim = dbl_limits; i < nitems(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);
        }
        /* NOTREACHED */
        return (FALSE);
}