void
fmpr_divappr_abs_ubound(fmpr_t z, const fmpr_t x, const fmpr_t y, slong prec)
{
if (fmpr_is_special(x) || fmpr_is_special(y) || fmpz_is_pm1(fmpr_manref(y)))
{
fmpr_div(z, x, y, prec, FMPR_RND_UP);
fmpr_abs(z, z);
}
else
{
fmpz_t t, u;
slong xbits, ybits, tbits, ubits, shift;
xbits = fmpz_bits(fmpr_manref(x));
ybits = fmpz_bits(fmpr_manref(y));
fmpz_init(t);
fmpz_init(u);
ubits = FLINT_MIN(ybits, prec);
tbits = prec + ubits + 1;
/* upper bound for |x|, shifted */
if (xbits <= tbits)
{
fmpz_mul_2exp(t, fmpr_manref(x), tbits - xbits);
fmpz_abs(t, t);
}
else if (fmpz_sgn(fmpr_manref(x)) > 0)
{
fmpz_cdiv_q_2exp(t, fmpr_manref(x), xbits - tbits);
}
else
{
fmpz_fdiv_q_2exp(t, fmpr_manref(x), xbits - tbits);
fmpz_neg(t, t);
}
/* lower bound for |y|, shifted */
if (ybits <= ubits)
fmpz_mul_2exp(u, fmpr_manref(y), ubits - ybits);
else
fmpz_tdiv_q_2exp(u, fmpr_manref(y), ybits - ubits);
fmpz_abs(u, u);
fmpz_cdiv_q(fmpr_manref(z), t, u);
shift = (ubits - ybits) - (tbits - xbits);
fmpz_sub(fmpr_expref(z), fmpr_expref(x), fmpr_expref(y));
if (shift >= 0)
fmpz_add_ui(fmpr_expref(z), fmpr_expref(z), shift);
else
fmpz_sub_ui(fmpr_expref(z), fmpr_expref(z), -shift);
_fmpr_normalise(fmpr_manref(z), fmpr_expref(z), prec, FMPR_RND_UP);
fmpz_clear(t);
fmpz_clear(u);
}
}
slong
fmpr_add_naive(fmpr_t z, const fmpr_t x, const fmpr_t y, slong prec, fmpr_rnd_t rnd)
{
slong shift, xsize, ysize;
if (fmpr_is_special(x) || fmpr_is_special(y))
{
return _fmpr_add_special(z, x, y, prec, rnd);
}
shift = _fmpz_sub_small(fmpr_expref(x), fmpr_expref(y));
if (shift == 0)
{
fmpz_add(fmpr_manref(z), fmpr_manref(x), fmpr_manref(y));
fmpz_set(fmpr_expref(z), fmpr_expref(x));
}
else if (shift > 0)
{
ysize = _fmpz_size(fmpr_manref(y)) * FLINT_BITS;
/* x and y do not overlap */
if (shift > ysize && prec != FMPR_PREC_EXACT)
{
/* y does not overlap with result */
if (ysize + prec - (slong) fmpz_bits(fmpr_manref(x)) < shift)
{
return _fmpr_add_eps(z, x, fmpz_sgn(fmpr_manref(y)), prec, rnd);
}
}
fmpz_add_mul2exp(fmpr_manref(z), fmpr_manref(y), fmpr_manref(x), shift);
fmpz_set(fmpr_expref(z), fmpr_expref(y));
}
else
{
shift = -shift;
xsize = _fmpz_size(fmpr_manref(x)) * FLINT_BITS;
/* x and y do not overlap */
if (shift > xsize && prec != FMPR_PREC_EXACT)
{
/* y does not overlap with result */
if (xsize + prec - (slong) fmpz_bits(fmpr_manref(y)) < shift)
{
return _fmpr_add_eps(z, y, fmpz_sgn(fmpr_manref(x)), prec, rnd);
}
}
fmpz_add_mul2exp(fmpr_manref(z), fmpr_manref(x), fmpr_manref(y), shift);
fmpz_set(fmpr_expref(z), fmpr_expref(x));
}
return _fmpr_normalise(fmpr_manref(z), fmpr_expref(z), prec, rnd);
}
slong
fmpr_sub(fmpr_t z, const fmpr_t x, const fmpr_t y, slong prec, fmpr_rnd_t rnd)
{
slong shift, xn, yn;
mp_limb_t xtmp, ytmp;
mp_ptr xptr, yptr;
fmpz xv, yv;
const fmpz * xexp;
const fmpz * yexp;
int xsign, ysign;
if (fmpr_is_special(x) || fmpr_is_special(y))
{
return _fmpr_sub_special(z, x, y, prec, rnd);
}
shift = _fmpz_sub_small(fmpr_expref(y), fmpr_expref(x));
if (shift >= 0)
{
xexp = fmpr_expref(x);
yexp = fmpr_expref(y);
xv = *fmpr_manref(x);
yv = *fmpr_manref(y);
}
else
{
xexp = fmpr_expref(y);
yexp = fmpr_expref(x);
xv = *fmpr_manref(y);
yv = *fmpr_manref(x);
}
FMPZ_GET_MPN_READONLY(xsign, xn, xptr, xtmp, xv)
FMPZ_GET_MPN_READONLY(ysign, yn, yptr, ytmp, yv)
if (shift >= 0)
{
ysign = !ysign;
}
else
{
shift = -shift;
xsign = !xsign;
}
if ((xn == 1) && (yn == 1) && (shift < FLINT_BITS))
return _fmpr_add_1x1(z, xptr[0], xsign, xexp, yptr[0], ysign, yexp, shift, prec, rnd);
else
return _fmpr_add_mpn(z, xptr, xn, xsign, xexp, yptr, yn, ysign, yexp, shift, prec, rnd);
}
int
fmpr_get_mpfr(mpfr_t x, const fmpr_t y, mpfr_rnd_t rnd)
{
int r;
if (fmpr_is_special(y))
{
if (fmpr_is_zero(y)) mpfr_set_zero(x, 0);
else if (fmpr_is_pos_inf(y)) mpfr_set_inf(x, 1);
else if (fmpr_is_neg_inf(y)) mpfr_set_inf(x, -1);
else mpfr_set_nan(x);
r = 0;
}
else if (COEFF_IS_MPZ(*fmpr_expref(y)))
{
flint_printf("exception: exponent too large to convert to mpfr");
abort();
}
else
{
if (!COEFF_IS_MPZ(*fmpr_manref(y)))
#if defined(__MINGW64__)
r = mpfr_set_sj_2exp(x, *fmpr_manref(y), *fmpr_expref(y), rnd);
#else
r = mpfr_set_si_2exp(x, *fmpr_manref(y), *fmpr_expref(y), rnd);
#endif
else
r = mpfr_set_z_2exp(x, COEFF_TO_PTR(*fmpr_manref(y)), *fmpr_expref(y), rnd);
if (!mpfr_regular_p(x))
{
flint_printf("exception: exponent too large to convert to mpfr");
abort();
}
}
void
fmpr_get_fmpq(fmpq_t y, const fmpr_t x)
{
if (fmpr_is_zero(x))
{
fmpq_zero(y);
}
else if (fmpr_is_special(x) || COEFF_IS_MPZ(*fmpr_expref(x)))
{
printf("exception: fmpr_get_fmpq: cannot convert to rational\n");
abort();
}
else
{
long exp = *fmpr_expref(x);
fmpz_set_ui(fmpq_denref(y), 1UL);
if (exp >= 0)
{
fmpz_mul_2exp(fmpq_numref(y), fmpr_manref(x), exp);
}
else
{
fmpz_set(fmpq_numref(y), fmpr_manref(x));
fmpz_mul_2exp(fmpq_denref(y), fmpq_denref(y), -exp);
}
}
}
static slong _fmpr_sub_special(fmpr_t z, const fmpr_t x, const fmpr_t y, slong prec, fmpr_rnd_t rnd)
{
if (fmpr_is_zero(x))
{
return fmpr_neg_round(z, y, prec, rnd);
}
else if (fmpr_is_zero(y))
{
return fmpr_set_round(z, x, prec, rnd);
}
else if (fmpr_is_nan(x) || fmpr_is_nan(y)
|| (fmpr_is_pos_inf(x) && fmpr_is_pos_inf(y))
|| (fmpr_is_neg_inf(x) && fmpr_is_neg_inf(y)))
{
fmpr_nan(z);
return FMPR_RESULT_EXACT;
}
else if (fmpr_is_special(x))
{
fmpr_set(z, x);
return FMPR_RESULT_EXACT;
}
else
{
fmpr_neg(z, y);
return FMPR_RESULT_EXACT;
}
}
static void
_fmpr_div_special(fmpr_t z, const fmpr_t x, const fmpr_t y)
{
if ((fmpr_is_zero(x) && !fmpr_is_zero(y) && !fmpr_is_nan(y)) ||
(fmpr_is_inf(y) && !fmpr_is_special(x)))
{
fmpr_zero(z);
}
else if (fmpr_is_zero(y) || (fmpr_is_special(x) && fmpr_is_special(y)) ||
fmpr_is_nan(x) || fmpr_is_nan(y))
{
fmpr_nan(z);
}
else if (fmpr_sgn(x) == fmpr_sgn(y))
fmpr_pos_inf(z);
else
fmpr_neg_inf(z);
}
int
fmpr_cmpabs(const fmpr_t x, const fmpr_t y)
{
int res, xsign, ysign;
fmpr_t t;
if (fmpr_equal(x, y))
return 0;
if (fmpr_is_special(x) || fmpr_is_special(y))
{
if (fmpr_is_nan(x) || fmpr_is_nan(y))
return 0;
if (fmpr_is_zero(x)) return -1;
if (fmpr_is_zero(y)) return 1;
if (fmpr_is_inf(x)) return fmpr_is_inf(y) ? 0 : 1;
if (fmpr_is_inf(y)) return -1;
return -1;
}
/* Reduces to integer comparison if bottom exponents are the same */
if (fmpz_equal(fmpr_expref(x), fmpr_expref(y)))
{
res = fmpz_cmpabs(fmpr_manref(x), fmpr_manref(y));
if (res != 0)
res = (res < 0) ? -1 : 1;
}
else
{
/* TODO: compare position of top exponents to avoid subtraction */
xsign = fmpr_sgn(x);
ysign = fmpr_sgn(y);
fmpr_init(t);
if (xsign == ysign)
fmpr_sub(t, x, y, 2, FMPR_RND_DOWN);
else
fmpr_add(t, x, y, 2, FMPR_RND_DOWN);
res = fmpr_sgn(t) * xsign;
fmpr_clear(t);
}
return res;
}
slong
fmpr_rsqrt(fmpr_t y, const fmpr_t x, slong prec, fmpr_rnd_t rnd)
{
slong r;
if (fmpr_is_special(x))
{
if (fmpr_is_zero(x))
fmpr_pos_inf(y);
else if (fmpr_is_pos_inf(x))
fmpr_zero(y);
else
fmpr_nan(y);
return FMPR_RESULT_EXACT;
}
if (fmpr_sgn(x) < 0)
{
fmpr_nan(y);
return FMPR_RESULT_EXACT;
}
/* special case: 4^n */
if (fmpz_is_one(fmpr_manref(x)) && fmpz_is_even(fmpr_expref(x)))
{
r = fmpr_set_round(y, x, prec, rnd);
fmpz_tdiv_q_2exp(fmpr_expref(y), fmpr_expref(y), 1);
fmpz_neg(fmpr_expref(y), fmpr_expref(y));
return r;
}
{
fmpr_t t;
fmpz_t e;
fmpr_init(t);
fmpz_init(e);
fmpz_neg(e, fmpr_expref(x));
if (fmpz_is_odd(e))
fmpz_add_ui(e, e, 1);
fmpr_mul_2exp_fmpz(t, x, e);
CALL_MPFR_FUNC(r, mpfr_rec_sqrt, y, t, prec, rnd);
fmpz_tdiv_q_2exp(e, e, 1);
fmpr_mul_2exp_fmpz(y, y, e);
fmpr_clear(t);
fmpz_clear(e);
return r;
}
}
int
fmpr_cmp(const fmpr_t x, const fmpr_t y)
{
int res, xsign, ysign;
fmpr_t t;
if (fmpr_equal(x, y))
return 0;
if (fmpr_is_special(x) || fmpr_is_special(y))
{
if (fmpr_is_nan(x) || fmpr_is_nan(y))
return 0;
if (fmpr_is_zero(y)) return fmpr_sgn(x);
if (fmpr_is_zero(x)) return -fmpr_sgn(y);
if (fmpr_is_pos_inf(x)) return 1;
if (fmpr_is_neg_inf(y)) return 1;
return -1;
}
xsign = fmpr_sgn(x);
ysign = fmpr_sgn(y);
if (xsign != ysign)
return (xsign < 0) ? -1 : 1;
/* Reduces to integer comparison if bottom exponents are the same */
if (fmpz_equal(fmpr_expref(x), fmpr_expref(y)))
return fmpz_cmp(fmpr_manref(x), fmpr_manref(y)) < 0 ? -1 : 1;
/* TODO: compare position of top exponents to avoid subtraction */
fmpr_init(t);
fmpr_sub(t, x, y, 2, FMPR_RND_DOWN);
res = fmpr_sgn(t);
fmpr_clear(t);
return res;
}
slong
fmpr_mul_fmpz(fmpr_t z, const fmpr_t x, const fmpz_t y, slong prec, fmpr_rnd_t rnd)
{
fmpz xv, yv;
fmpz yexp;
if (fmpr_is_special(x) || fmpz_is_zero(y))
{
if (fmpr_is_zero(x))
{
fmpr_zero(z);
}
else if (fmpz_is_zero(y) && fmpr_is_finite(x))
{
fmpr_zero(z);
}
else if (fmpr_is_inf(x) && !fmpz_is_zero(y))
{
if (fmpr_sgn(x) == fmpz_sgn(y))
fmpr_pos_inf(z);
else
fmpr_neg_inf(z);
}
else
{
fmpr_nan(z);
}
return FMPR_RESULT_EXACT;
}
xv = *fmpr_manref(x);
yv = *y;
if (!COEFF_IS_MPZ(xv) && !COEFF_IS_MPZ(yv))
{
mp_limb_t ytmp;
unsigned int bc;
ytmp = FLINT_ABS(yv);
count_trailing_zeros(bc, ytmp);
ytmp >>= bc;
yexp = bc;
return _fmpr_mul_1x1(z, FLINT_ABS(xv), fmpr_expref(x),
ytmp, &yexp, (xv ^ yv) < 0, prec, rnd);
}
void
arf_set_fmpr(arf_t y, const fmpr_t x)
{
if (fmpr_is_special(x))
{
if (fmpr_is_zero(x))
arf_zero(y);
else if (fmpr_is_pos_inf(x))
arf_pos_inf(y);
else if (fmpr_is_neg_inf(x))
arf_neg_inf(y);
else
arf_nan(y);
}
else
{
arf_set_fmpz(y, fmpr_manref(x));
fmpz_add_inline(ARF_EXPREF(y), ARF_EXPREF(y), fmpr_expref(x));
}
}
static void
_fmprb_gamma(fmprb_t y, const fmprb_t x, long prec, int inverse)
{
int reflect;
long r, n, wp;
fmprb_t t, u, v;
if (fmprb_is_exact(x))
{
const fmpr_struct * mid = fmprb_midref(x);
if (fmpr_is_special(mid))
{
if (!inverse && fmpr_is_pos_inf(mid))
{
fmprb_set(y, x);
}
else if (fmpr_is_nan(mid) || fmpr_is_neg_inf(mid) || !inverse)
{
fmpr_nan(fmprb_midref(y));
fmpr_pos_inf(fmprb_radref(y));
}
else
{
fmprb_zero(y);
}
return;
}
else
{
const fmpz exp = *fmpr_expref(mid);
const fmpz man = *fmpr_manref(mid);
/* fast gamma(n), gamma(n/2) or gamma(n/4) */
if (!COEFF_IS_MPZ(exp) && (exp >= -2) &&
((double) fmpz_bits(&man) + exp < prec))
{
fmpq_t a;
fmpq_init(a);
fmpr_get_fmpq(a, mid);
fmprb_gamma_fmpq(y, a, prec + 2 * inverse);
if (inverse)
fmprb_ui_div(y, 1, y, prec);
fmpq_clear(a);
return;
}
}
}
wp = prec + FLINT_BIT_COUNT(prec);
gamma_stirling_choose_param_fmprb(&reflect, &r, &n, x, 1, 0, wp);
fmprb_init(t);
fmprb_init(u);
fmprb_init(v);
if (reflect)
{
/* gamma(x) = (rf(1-x, r) * pi) / (gamma(1-x+r) sin(pi x)) */
fmprb_sub_ui(t, x, 1, wp);
fmprb_neg(t, t);
gamma_rising_fmprb_ui_bsplit(u, t, r, wp);
fmprb_const_pi(v, wp);
fmprb_mul(u, u, v, wp);
fmprb_add_ui(t, t, r, wp);
gamma_stirling_eval_fmprb(v, t, n, 0, wp);
fmprb_exp(v, v, wp);
fmprb_sin_pi(t, x, wp);
fmprb_mul(v, v, t, wp);
}
else
{
/* gamma(x) = gamma(x+r) / rf(x,r) */
fmprb_add_ui(t, x, r, wp);
gamma_stirling_eval_fmprb(u, t, n, 0, wp);
fmprb_exp(u, u, prec);
gamma_rising_fmprb_ui_bsplit(v, x, r, wp);
}
if (inverse)
fmprb_div(y, v, u, prec);
else
fmprb_div(y, u, v, prec);
fmprb_clear(t);
fmprb_clear(u);
fmprb_clear(v);
}
slong
fmpr_div(fmpr_t z, const fmpr_t x, const fmpr_t y, slong prec, fmpr_rnd_t rnd)
{
if (fmpr_is_special(x) || fmpr_is_special(y))
{
_fmpr_div_special(z, x, y);
return FMPR_RESULT_EXACT;
}
/* division by power of two <=> shift exponents */
if (fmpz_is_pm1(fmpr_manref(y)))
{
if (fmpz_is_one(fmpr_manref(y)))
fmpz_set(fmpr_manref(z), fmpr_manref(x));
else
fmpz_neg(fmpr_manref(z), fmpr_manref(x));
fmpz_sub(fmpr_expref(z), fmpr_expref(x), fmpr_expref(y));
return _fmpr_normalise(fmpr_manref(z), fmpr_expref(z), prec, rnd);
}
else
{
slong xbits, ybits, extra, extra_pad, extra_control;
int negative;
fmpz_t t, u;
/* todo: work out exact needed shift */
xbits = fmpz_bits(fmpr_manref(x));
ybits = fmpz_bits(fmpr_manref(y));
extra = prec - xbits + ybits;
extra = FLINT_MAX(extra, 0);
extra_pad = 32;
extra_control = 24;
extra += extra_pad;
fmpz_init(t);
fmpz_init(u);
fmpz_mul_2exp(t, fmpr_manref(x), extra);
fmpz_tdiv_q(u, t, fmpr_manref(y));
if (low_bits_are_zero(u, extra_control))
{
fmpz_t v;
fmpz_init(v);
fmpz_mul(v, u, fmpr_manref(y));
negative = fmpz_sgn(fmpr_manref(x)) != fmpz_sgn(fmpr_manref(y));
if (!fmpz_equal(t, v))
{
if (negative)
fmpz_sub_ui(u, u, 1);
else
fmpz_add_ui(u, u, 1);
}
fmpz_clear(v);
}
fmpz_swap(fmpr_manref(z), u);
fmpz_clear(t);
fmpz_clear(u);
fmpz_sub(fmpr_expref(z), fmpr_expref(x), fmpr_expref(y));
fmpz_sub_ui(fmpr_expref(z), fmpr_expref(z), extra);
return _fmpr_normalise(fmpr_manref(z), fmpr_expref(z), prec, rnd);
}
}
