int
sdecode_number(const byte *str, int format, ref *np)
{ switch ( format & 0x170 )
{
case num_int32: case num_int32 + 16:
if ( (format & 31) == 0 )
{ np->value.intval = sdecodelong(str, format);
return t_integer;
}
else
{ np->value.realval =
(double)sdecodelong(str, format) *
binary_scale[format & 31];
return t_real;
}
case num_int16:
if ( (format & 15) == 0 )
{ np->value.intval = sdecodeshort(str, format);
return t_integer;
}
else
{ np->value.realval =
sdecodeshort(str, format) *
binary_scale[format & 15];
return t_real;
}
case num_float:
np->value.realval = sdecodefloat(str, format);
return t_real;
default:
return_error(e_syntaxerror); /* invalid format?? */
}
}
/* Decode a float. We assume that native floats occupy 32 bits. */
float
sdecodefloat(const byte * p, int format)
{
bits32 lnum;
float fnum;
if ((format & ~(num_msb | num_lsb)) == num_float_native) {
/*
* Just read 4 bytes and interpret them as a float, ignoring
* any indication of byte ordering.
*/
memcpy(&lnum, p, 4);
fnum = *(float *)&lnum;
} else {
lnum = (bits32) sdecodelong(p, format);
#if !arch_floats_are_IEEE
{
/* We know IEEE floats take 32 bits. */
/* Convert IEEE float to native float. */
int sign_expt = lnum >> 23;
int expt = sign_expt & 0xff;
int32_t mant = lnum & 0x7fffff;
if (expt == 0 && mant == 0)
fnum = 0;
else {
mant += 0x800000;
fnum = (float)ldexp((float)mant, expt - 127 - 23);
}
if (sign_expt & 0x100)
fnum = -fnum;
}
#else
fnum = *(float *)&lnum;
#endif
}
return fnum;
}
/* Decode a float. We don't handle non-IEEE native representations yet. */
float
sdecodefloat(register const byte *p, int format)
{ float fnum;
if ( format != num_float_native )
{ bits32 lnum = (bits32)sdecodelong(p, format);
/* We know IEEE floats take 32 bits. */
#if !arch_floats_are_IEEE
/* Convert IEEE float to native float. */
int sign_expt = lnum >> 23;
int expt = sign_expt & 0xff;
long mant = lnum & 0x7fffff;
if ( expt == 0 && mant == 0 )
fnum = 0;
else
{ mant += 0x800000;
fnum = (float)ldexp((float)mant, expt - 127 - 24);
}
if ( sign_expt & 0x100 )
fnum = -fnum;
#else
fnum = *(float *)&lnum;
#endif
}
