int
_arf_add_eps(arf_t s, const arf_t x, int sgn, long prec, arf_rnd_t rnd)
{
arf_t t;
long bits;
bits = arf_bits(x);
if (bits == 0)
{
printf("_arf_add_eps\n");
abort();
}
bits = FLINT_MAX(bits, prec) + 10;
arf_init(t);
arf_set_si(t, sgn);
arf_mul_2exp_fmpz(t, t, ARF_EXPREF(x));
arf_mul_2exp_si(t, t, -bits);
arf_add(s, x, t, prec, rnd);
arf_clear(t);
return 1;
}
void
arb_atan_arf_via_mpfr(arb_t z, const arf_t x, slong prec)
{
mpfr_t t, u;
int exact;
mpfr_init2(t, 2 + arf_bits(x));
mpfr_init2(u, prec);
mpfr_set_emin(MPFR_EMIN_MIN);
mpfr_set_emax(MPFR_EMAX_MAX);
arf_get_mpfr(t, x, MPFR_RNDD);
exact = (mpfr_atan(u, t, MPFR_RNDD) == 0);
arf_set_mpfr(arb_midref(z), u);
if (!exact)
arf_mag_set_ulp(arb_radref(z), arb_midref(z), prec);
mpfr_clear(t);
mpfr_clear(u);
}
static __inline__ void
_arb_vec_get_fmpz_2exp_blocks(fmpz * coeffs, fmpz * exps,
slong * blocks, const fmpz_t scale, arb_srcptr x, slong len, slong prec)
{
fmpz_t top, bot, t, b, v, block_top, block_bot;
slong i, j, s, block, bits, maxheight;
int in_zero;
fmpz_init(top);
fmpz_init(bot);
fmpz_init(t);
fmpz_init(b);
fmpz_init(v);
fmpz_init(block_top);
fmpz_init(block_bot);
blocks[0] = 0;
block = 0;
in_zero = 1;
if (prec == ARF_PREC_EXACT)
maxheight = ARF_PREC_EXACT;
else
maxheight = ALPHA * prec + BETA;
for (i = 0; i < len; i++)
{
bits = arf_bits(arb_midref(x + i));
/* Skip (must be zero, since we assume there are no Infs/NaNs). */
if (bits == 0)
continue;
/* Bottom and top exponent of current number */
fmpz_set(top, ARF_EXPREF(arb_midref(x + i)));
fmpz_submul_ui(top, scale, i);
fmpz_sub_ui(bot, top, bits);
/* Extend current block. */
if (in_zero)
{
fmpz_swap(block_top, top);
fmpz_swap(block_bot, bot);
}
else
{
fmpz_max(t, top, block_top);
fmpz_min(b, bot, block_bot);
fmpz_sub(v, t, b);
/* extend current block */
if (fmpz_cmp_ui(v, maxheight) < 0)
{
fmpz_swap(block_top, t);
fmpz_swap(block_bot, b);
}
else /* start new block */
{
/* write exponent for previous block */
fmpz_set(exps + block, block_bot);
block++;
blocks[block] = i;
fmpz_swap(block_top, top);
fmpz_swap(block_bot, bot);
}
}
in_zero = 0;
}
/* write exponent for last block */
fmpz_set(exps + block, block_bot);
/* end marker */
blocks[block + 1] = len;
/* write the block data */
for (i = 0; blocks[i] != len; i++)
{
for (j = blocks[i]; j < blocks[i + 1]; j++)
{
if (arf_is_special(arb_midref(x + j)))
{
fmpz_zero(coeffs + j);
}
else
{
/* TODO: make this a single operation */
arf_get_fmpz_2exp(coeffs + j, bot, arb_midref(x + j));
fmpz_mul_ui(t, scale, j);
fmpz_sub(t, bot, t);
s = _fmpz_sub_small(t, exps + i);
if (s < 0) abort(); /* Bug catcher */
fmpz_mul_2exp(coeffs + j, coeffs + j, s);
}
}
}
fmpz_clear(top);
fmpz_clear(bot);
fmpz_clear(t);
fmpz_clear(b);
fmpz_clear(v);
fmpz_clear(block_top);
fmpz_clear(block_bot);
}
