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/* this file is #include'd (many times) by numbers.c */
#if HAVE_CONFIG_H
# include <config.h>
#endif
#ifndef UNSIGNED_ITYPE
#ifdef UNSIGNED
#define UNSIGNED_ITYPE ITYPE
#else
#define UNSIGNED_ITYPE unsigned ITYPE
#endif
#endif
#define UNSIGNED_ITYPE_MAX (~((UNSIGNED_ITYPE)0))
#ifndef SIZEOF_ITYPE
#define SIZEOF_ITYPE (2*SIZEOF_SCM_T_BITS)
#endif
ITYPE
NUM2INTEGRAL (SCM num, unsigned long int pos, const char *s_caller)
{
if (SCM_INUMP (num))
{ /* immediate */
scm_t_signed_bits n = SCM_INUM (num);
#ifdef UNSIGNED
if (n < 0)
scm_out_of_range (s_caller, num);
#endif
#if SIZEOF_ITYPE >= SIZEOF_SCM_T_BITS
/* the target type is large enough to hold any possible inum */
return (ITYPE) n;
#else
/* an inum can be out of range, so check */
#ifdef UNSIGNED
/* n is known to be >= 0 */
if ((scm_t_bits) n > UNSIGNED_ITYPE_MAX)
scm_out_of_range (s_caller, num);
#else
if (((ITYPE)n) != n)
scm_out_of_range (s_caller, num);
#endif
return (ITYPE) n;
#endif /* SIZEOF_ITYPE >= SIZEOF_SCM_T_BITS */
}
else if (SCM_BIGP (num))
{ /* bignum */
#if SIZEOF_ITYPE >= SIZEOF_SCM_T_BITS
UNSIGNED_ITYPE pos_res = 0;
size_t l;
#ifdef UNSIGNED
if (SCM_BIGSIGN (num))
scm_out_of_range (s_caller, num);
#endif
for (l = SCM_NUMDIGS (num); l--;)
{
if (pos_res > SCM_BIGDN (UNSIGNED_ITYPE_MAX))
scm_out_of_range (s_caller, num);
pos_res = SCM_I_BIGUP (ITYPE, pos_res) + SCM_BDIGITS (num)[l];
}
#ifdef UNSIGNED
return pos_res;
#else
if (SCM_BIGSIGN (num))
{
ITYPE res = -((ITYPE)pos_res);
if (res <= 0)
return res;
else
scm_out_of_range (s_caller, num);
}
else
{
ITYPE res = (ITYPE)pos_res;
if (res >= 0)
return res;
else
scm_out_of_range (s_caller, num);
}
#endif
#else /* SIZEOF_ITYPE >= SIZEOF_SCM_T_BITS */
scm_out_of_range (s_caller, num);
#endif
}
else
scm_wrong_type_arg (s_caller, pos, num);
}
SCM
INTEGRAL2NUM (ITYPE n)
{
/* If we know the size of the type, determine at compile time
whether we need to perform the FIXABLE test or not. This is not
done to get more optimal code out of the compiler (it can figure
this out on its own already), but to avoid a spurious warning.
If we don't know the size, assume that the test must be done.
*/
#if SIZEOF_ITYPE >= SIZEOF_SCM_T_BITS
#ifndef UNSIGNED
if (SCM_FIXABLE (n))
#else
if (SCM_POSFIXABLE (n))
#endif
#endif
return SCM_MAKINUM ((scm_t_signed_bits) n);
#ifdef SCM_BIGDIG
return INTEGRAL2BIG (n);
#else
return scm_make_real ((double) n);
#endif
}
#ifdef SCM_BIGDIG
SCM
INTEGRAL2BIG (ITYPE n)
{
SCM res;
int neg_p;
unsigned int n_digits;
size_t i;
SCM_BIGDIG *digits;
#ifndef UNSIGNED
neg_p = (n < 0);
if (neg_p) n = -n;
#else
neg_p = 0;
#endif
#ifndef UNSIGNED
/* If n is still negative here, it must be the minimum value of the
type (assuming twos-complement, but we are tied to that anyway).
If this is the case, we can not count the number of digits by
right-shifting n until it is zero.
*/
if (n < 0)
{
/* special case */
n_digits =
(sizeof (ITYPE) + sizeof (SCM_BIGDIG) - 1) / sizeof (SCM_BIGDIG);
}
else
#endif
{
ITYPE tn;
for (tn = n, n_digits = 0;
tn;
++n_digits, tn = SCM_BIGDN (tn))
;
}
i = 0;
res = scm_i_mkbig (n_digits, neg_p);
digits = SCM_BDIGITS (res);
while (i < n_digits)
{
digits[i++] = SCM_BIGLO (n);
n = SCM_BIGDN (n);
}
return res;
}
#endif
/* clean up */
#undef INTEGRAL2NUM
#undef INTEGRAL2BIG
#undef NUM2INTEGRAL
#ifdef UNSIGNED
#undef UNSIGNED
#endif
#undef ITYPE
#undef SIZEOF_ITYPE
#undef UNSIGNED_ITYPE
#undef UNSIGNED_ITYPE_MAX
/*
Local Variables:
c-file-style: "gnu"
End:
*/
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