char
float_gamma(
floatnum x,
int digits)
{
signed char sign;
char result;
if (!chckmathparam(x, digits))
return 0;
sign = float_getsign(x);
if (float_isinteger(x))
{
if (sign <= 0)
return _seterror(x, ZeroDivide);
result = _gammaint(x, digits);
}
else if (float_getlength(x) - float_getexponent(x) == 2
&& float_getdigit(x, float_getlength(x) - 1) == 5)
result = _gamma0_5(x, digits);
else
result = _gamma(x, digits);
if (!result)
{
if (sign < 0)
float_seterror(Underflow);
else
float_seterror(Overflow);
float_setnan(x);
}
return result;
}
char
_trigreduce(
floatnum x,
int digits)
{
floatstruct tmp;
int expx, save;
signed char sgn;
char odd;
if (float_abscmp(x, &cPi) <= 0)
return 1;
expx = float_getexponent(x);
if (expx > float_getlength(&cPi) - digits)
return 0;
save = float_setprecision(MAXDIGITS);
float_create(&tmp);
sgn = float_getsign(x);
float_abs(x);
float_divmod(&tmp, x, x, &cPi, INTQUOT);
float_setprecision(save);
odd = float_isodd(&tmp);
if (odd)
float_sub(x, x, &cPi, digits+1);
if (sgn < 0)
float_neg(x);
float_free(&tmp);
return 1;
}
static void
_setfndesc(
p_number_desc n,
floatnum x)
{
int digits;
n->intpart.seq.base = 10;
digits = _max(float_getexponent(x) + 1, 0);
n->intpart.seq.digits = digits;
n->intpart.seq.trailing0 = _max(digits - float_getlength(x), 0);
n->intpart.seq.param = x;
n->intpart.getdigit = _getfnintdigit;
n->fracpart.seq.base = 10;
n->fracpart.seq.leadingSignDigits = _max(-float_getexponent(x) - 1, 0);
n->fracpart.seq.digits = float_getlength(x) - digits
+ n->fracpart.seq.leadingSignDigits;
n->fracpart.seq.param = x;
n->fracpart.getdigit = _getfnfracdigit;
}
Error
pack2floatnum(
floatnum x,
p_number_desc n)
{
floatstruct tmp;
int digits;
int saveerr;
int saverange;
Error result;
signed char base;
if ((result = _pack2int(x, &n->intpart)) != Success)
return result;
if (float_isnan(x))
return Success;
saveerr = float_geterror();
saverange = float_setrange(MAXEXP);
float_create(&tmp);
float_move(&tmp, x);
float_setzero(x);
digits = DECPRECISION - float_getexponent(&tmp);
if (digits <= 0
|| (result = _pack2frac(x, &n->fracpart, digits)) == Success)
float_add(x, x, &tmp, DECPRECISION);
if (result != Success)
return result;
if ((!float_getlength(x)) == 0) /* no zero, no NaN? */
{
base = n->prefix.base;
float_setinteger(&tmp, base);
if (n->exp >= 0)
{
_raiseposi_(&tmp, n->exp, DECPRECISION + 2);
float_mul(x, x, &tmp, DECPRECISION + 2);
}
else
{
_raiseposi_(&tmp, -n->exp, DECPRECISION + 2);
float_div(x, x, &tmp, DECPRECISION + 2);
}
}
float_free(&tmp);
float_setsign(x, n->prefix.sign == IO_SIGN_COMPLEMENT? -1 : n->prefix.sign);
float_geterror();
float_seterror(saveerr);
float_setrange(saverange);
if (!float_isvalidexp(float_getexponent(x)))
float_setnan(x);
return float_isnan(x)? IOExpOverflow : Success;
}