OpenSolaris_b135/lib/libnsl/rpc/xdr_float.c
/*
* CDDL HEADER START
*
* The contents of this file are subject to the terms of the
* Common Development and Distribution License (the "License").
* You may not use this file except in compliance with the License.
*
* You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
* or http://www.opensolaris.org/os/licensing.
* See the License for the specific language governing permissions
* and limitations under the License.
*
* When distributing Covered Code, include this CDDL HEADER in each
* file and include the License file at usr/src/OPENSOLARIS.LICENSE.
* If applicable, add the following below this CDDL HEADER, with the
* fields enclosed by brackets "[]" replaced with your own identifying
* information: Portions Copyright [yyyy] [name of copyright owner]
*
* CDDL HEADER END
*/
/*
* Copyright 2006 Sun Microsystems, Inc. All rights reserved.
* Use is subject to license terms.
*/
/* Copyright (c) 1983, 1984, 1985, 1986, 1987, 1988, 1989 AT&T */
/* All Rights Reserved */
/*
* Portions of this source code were derived from Berkeley
* 4.3 BSD under license from the Regents of the University of
* California.
*/
#pragma ident "%Z%%M% %I% %E% SMI"
/*
* Generic XDR routines impelmentation.
*
* 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 "mt.h"
#include <sys/types.h>
#include <stdio.h>
#include <rpc/types.h>
#include <rpc/xdr.h>
/*
* This routine works on Suns, 3b2, 68000s, 386 and Vaxen in a manner
* which is very efficient as bit twiddling is all that is needed. All
* other machines can use this code but the code is inefficient as
* various mathematical operations are used to generate the ieee format.
* In addition rounding errors may occur due to the calculations involved.
* To be most efficient, new machines should have their own ifdefs.
* The encoding routines will fail if the machines try to encode a
* float/double whose value can not be represented by the ieee format,
* e.g. the exponent is too big/small.
* ieee largest float = (2 ^ 128) * 0x1.fffff
* ieee smallest float = (2 ^ -127) * 0x1.00000
* ieee largest double = (2 ^ 1024) * 0x1.fffff
* ieee smallest double = (2 ^ -1023) * 0x1.00000
* The decoding routines assumes that the receiving machine can handle
* floats/doubles as large/small as the values stated above. If you
* use a machine which can not represent these values, you will need
* to put ifdefs in the decode sections to identify areas of failure.
*/
#if defined(vax)
/*
* What IEEE single precision floating point looks like this on a
* vax.
*/
struct ieee_single {
unsigned int mantissa: 23;
unsigned int exp : 8;
unsigned int sign : 1;
};
#define IEEE_SNG_BIAS 0x7f
#define VAX_SNG_BIAS 0x81
/* 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
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)
{
#if defined(vax)
struct ieee_single is;
struct vax_single vs, *vsp;
struct sgl_limits *lim;
size_t i;
#endif
switch (xdrs->x_op) {
case XDR_ENCODE:
#if defined(mc68000) || defined(sparc) || defined(u3b2) || \
defined(u3b15) || defined(i386) || defined(amd64)
return (XDR_PUTINT32(xdrs, (int *)fp));
#else
#if defined(vax)
vs = *((struct vax_single *)fp);
if ((vs.exp == 1) || (vs.exp == 2)) {
/* map these to subnormals */
is.exp = 0;
is.mantissa = (vs.mantissa1 << 16) | vs.mantissa2;
/* lose some precision */
is.mantissa >>= 3 - vs.exp;
is.mantissa += (1 << (20 + vs.exp));
goto shipit;
}
for (i = 0, lim = sgl_limits;
i < (int)(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_PUTINT32(xdrs, (int32_t *)&is));
#else
{
/*
* Every machine can do this, its just not very efficient.
* In addtion, some rounding errors may occur do to the
* calculations involved.
*/
float f;
int neg = 0;
int exp = 0;
int32_t val;
f = *fp;
if (f == 0) {
val = 0;
return (XDR_PUTINT32(xdrs, &val));
}
if (f < 0) {
f = 0 - f;
neg = 1;
}
while (f < 1) {
f = f * 2;
--exp;
}
while (f >= 2) {
f = f/2;
++exp;
}
if ((exp > 128) || (exp < -127)) {
/* over or under flowing ieee exponent */
return (FALSE);
}
val = neg;
val = val << 8; /* for the exponent */
val += 127 + exp; /* 127 is the bias */
val = val << 23; /* for the mantissa */
val += (int32_t)((f - 1) * 8388608); /* 2 ^ 23 */
return (XDR_PUTINT32(xdrs, &val));
}
#endif
#endif
case XDR_DECODE:
#if defined(mc68000) || defined(sparc) || defined(u3b2) || \
defined(u3b15) || defined(i386) || defined(amd64)
return (XDR_GETINT32(xdrs, (int *)fp));
#else
#if defined(vax)
vsp = (struct vax_single *)fp;
if (!XDR_GETINT32(xdrs, (int32_t *)&is))
return (FALSE);
for (i = 0, lim = sgl_limits;
i < (int)(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;
} else if ((is.exp == 0) && (lim->ieee.exp == 0)) {
/* Special Case */
unsigned tmp = is.mantissa >> 20;
if (tmp >= 4) {
vsp->exp = 2;
} else if (tmp >= 2) {
vsp->exp = 1;
} else {
*vsp = min.s;
break;
} /* else */
tmp = is.mantissa - (1 << (20 + vsp->exp));
tmp <<= 3 - vsp->exp;
vsp->mantissa2 = tmp;
vsp->mantissa1 = (tmp >> 16);
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);
#else
{
/*
* Every machine can do this, its just not very
* efficient. It assumes that the decoding machine's
* float can represent any value in the range of
* ieee largest float = (2 ^ 128) * 0x1.fffff
* to
* ieee smallest float = (2 ^ -127) * 0x1.00000
* In addtion, some rounding errors may occur do to the
* calculations involved.
*/
float f;
int neg = 0;
int exp = 0;
int32_t val;
if (!XDR_GETINT32(xdrs, (int32_t *)&val))
return (FALSE);
neg = val & 0x80000000;
exp = (val & 0x7f800000) >> 23;
exp -= 127; /* subtract exponent base */
f = (val & 0x007fffff) * 0.00000011920928955078125;
/* 2 ^ -23 */
f++;
while (exp != 0) {
if (exp < 0) {
f = f/2.0;
++exp;
} else {
f = f * 2.0;
--exp;
}
}
if (neg)
f = 0 - f;
*fp = f;
}
return (TRUE);
#endif
#endif
case XDR_FREE:
return (TRUE);
}
return (FALSE);
}
/*
* This routine works on Suns (Sky / 68000's) and Vaxen.
*/
#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)
{
int *lp;
#if defined(vax)
struct ieee_double id;
struct vax_double vd;
struct dbl_limits *lim;
size_t i;
#endif
switch (xdrs->x_op) {
case XDR_ENCODE:
#if defined(mc68000) || defined(u3b2) || defined(u3b15) || \
defined(_LONG_LONG_HTOL)
lp = (int *)dp;
return (XDR_PUTINT32(xdrs, lp++) && XDR_PUTINT32(xdrs, lp));
#else
#if defined(_LONG_LONG_LTOH)
lp = (int *)dp;
lp++;
return (XDR_PUTINT32(xdrs, lp--) && XDR_PUTINT32(xdrs, lp));
#else
#if defined(vax)
vd = *((struct vax_double *)dp);
for (i = 0, lim = dbl_limits;
i < (int)(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 = (int32_t *)&id;
#else
{
/*
* Every machine can do this, its just not very efficient.
* In addtion, some rounding errors may occur do to the
* calculations involved.
*/
double d;
int neg = 0;
int exp = 0;
int32_t val[2];
d = *dp;
if (d == 0) {
val[0] = 0;
val[1] = 0;
lp = val;
return (XDR_PUTINT32(xdrs, lp++) &&
XDR_PUTINT32(xdrs, lp));
}
if (d < 0) {
d = 0 - d;
neg = 1;
}
while (d < 1) {
d = d * 2;
--exp;
}
while (d >= 2) {
d = d/2;
++exp;
}
if ((exp > 1024) || (exp < -1023)) {
/* over or under flowing ieee exponent */
return (FALSE);
}
val[0] = neg;
val[0] = val[0] << 11; /* for the exponent */
val[0] += 1023 + exp; /* 1023 is the bias */
val[0] = val[0] << 20; /* for the mantissa */
val[0] += (int32_t)((d - 1) * 1048576); /* 2 ^ 20 */
val[1] += (int32_t)((((d - 1) * 1048576) - val[0])
* 4294967296);
/* 2 ^ 32 */
lp = val;
}
#endif
return (XDR_PUTINT32(xdrs, lp++) && XDR_PUTINT32(xdrs, lp));
#endif
#endif
case XDR_DECODE:
#if defined(mc68000) || defined(u3b2) || defined(u3b15) || \
defined(_LONG_LONG_HTOL)
lp = (int *)dp;
return (XDR_GETINT32(xdrs, lp++) && XDR_GETINT32(xdrs, lp));
#else
#if defined(_LONG_LONG_LTOH)
lp = (int *)dp;
lp++;
return (XDR_GETINT32(xdrs, lp--) && XDR_GETINT32(xdrs, lp));
#else
#if defined(vax)
lp = (int32_t *)&id;
if (!XDR_GETINT32(xdrs, lp++) || !XDR_GETINT32(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);
#else
{
/*
* Every machine can do this, its just not very
* efficient. It assumes that the decoding machine's
* double can represent any value in the range of
* ieee largest double = (2 ^ 1024) * 0x1.fffffffffffff
* to
* ieee smallest double = (2 ^ -1023) * 0x1.0000000000000
* In addtion, some rounding errors may occur do to the
* calculations involved.
*/
double d;
int neg = 0;
int exp = 0;
int32_t val[2];
lp = val;
if (!XDR_GETINT32(xdrs, lp++) || !XDR_GETINT32(xdrs, lp))
return (FALSE);
neg = val[0] & 0x80000000;
exp = (val[0] & 0x7ff00000) >> 20;
exp -= 1023; /* subtract exponent base */
d = (val[0] & 0x000fffff) * 0.00000095367431640625;
/* 2 ^ -20 */
d += (val[1] * 0.0000000000000002220446049250313);
/* 2 ^ -52 */
d++;
while (exp != 0) {
if (exp < 0) {
d = d/2.0;
++exp;
} else {
d = d * 2.0;
--exp;
}
}
if (neg)
d = 0 - d;
*dp = d;
}
#endif
#endif
#endif
case XDR_FREE:
return (TRUE);
}
return (FALSE);
}
/* ARGSUSED */
bool_t
xdr_quadruple(XDR *xdrs, long double *fp)
{
/*
* The Sparc uses IEEE FP encoding, so just do a byte copy
*/
#if !defined(sparc)
return (FALSE);
#else
switch (xdrs->x_op) {
case XDR_ENCODE:
return (XDR_PUTBYTES(xdrs, (char *)fp, sizeof (long double)));
case XDR_DECODE:
return (XDR_GETBYTES(xdrs, (char *)fp, sizeof (long double)));
case XDR_FREE:
return (TRUE);
}
return (FALSE);
#endif
}