ScmObj Scm_MakeBignumFromDouble(double val)
{
if (LONG_MIN <= val
#if SIZEOF_LONG == 4
&& val <= LONG_MAX
#else
&& val <= nextafter((double)LONG_MAX, 0.0)
#endif
)
return Scm_MakeBignumFromSI((long)val);
int exponent, sign;
ScmObj mantissa = Scm_DecodeFlonum(val, &exponent, &sign);
if (!SCM_NUMBERP(mantissa)) {
Scm_Error("can't convert %lf to an integer", val);
}
ScmObj b = Scm_Ash(mantissa, exponent);
if (sign < 0) b = Scm_Negate(b);
/* always returns bignum */
if (SCM_INTP(b)) {
return Scm_MakeBignumFromSI(SCM_INT_VALUE(b));
} else {
return b;
}
}
ScmObj Scm_MakeBignumFromDouble(double val)
{
int exponent, sign;
ScmObj mantissa, b;
if (val >= LONG_MIN && val <= LONG_MAX) {
return Scm_MakeBignumFromSI((long)val);
}
mantissa = Scm_DecodeFlonum(val, &exponent, &sign);
if (!SCM_NUMBERP(mantissa)) {
Scm_Error("can't convert %lf to an integer", val);
}
b = Scm_Ash(mantissa, exponent);
if (sign < 0) b = Scm_Negate(b);
/* always returns bignum */
if (SCM_INTP(b)) {
return Scm_MakeBignumFromSI(SCM_INT_VALUE(b));
} else {
return b;
}
}
