newlib-cygwin/newlib/libc/xdr/xdr_float_vax.c

253 lines
6.9 KiB
C

/*
* Copyright (c) 2009, Sun Microsystems, Inc.
* All rights reserved.
*
* 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 Sun Microsystems, 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_vax.c, XDR floating point routines for vax.
*
* 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.
*/
#ifndef XDR_FLOAT_C
#error "Must be included from xdr_float.c"
#endif
/* 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
/* *INDENT-OFF*
*/
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 */
}
};
/* *INDENT-ON*
*/
bool_t
xdr_float (XDR * xdrs,
float *fp)
{
struct ieee_single is;
struct vax_single vs, *vsp;
struct sgl_limits *lim;
int i;
switch (xdrs->x_op)
{
case XDR_ENCODE:
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_PUTINT32 (xdrs, (int32_t *) & is));
case XDR_DECODE:
vsp = (struct vax_single *) fp;
if (!XDR_GETINT32 (xdrs, (int32_t *) & 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;
case XDR_FREE:
return TRUE;
}
return FALSE;
}
#if !defined(_DOUBLE_IS_32BITS)
/* 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)
/* *INDENT-OFF*
*/
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 */
}
};
/* *INDENT-ON*
*/
bool_t
xdr_double (XDR * xdrs,
double *dp)
{
int32_t *lp;
struct ieee_double id;
struct vax_double vd;
struct dbl_limits *lim;
int i;
switch (xdrs->x_op)
{
case XDR_ENCODE:
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 = (int32_t *) & id;
return (XDR_PUTINT32 (xdrs, lp++) && XDR_PUTINT32 (xdrs, lp));
case XDR_DECODE:
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;
case XDR_FREE:
return TRUE;
}
return FALSE;
}
#endif /* !_DOUBLE_IS_32BITS */