int iv_fits_double(SV * t, ...) { dXSARGS; int i, count = 0; for(i = 0; i < items; i++) { IV arg = SvIV(ST(i)); int sign = ( arg > 0 || SvUOK(ST(i)) ) ? 1 : -1; UV valid_bits = ((arg & -arg) << 53) - 1; if(!((arg * sign) & (~valid_bits))) count++; } return count; }