diff --git a/bernoulli.h b/bernoulli.h
index 68d37266..0c6c144b 100644
--- a/bernoulli.h
+++ b/bernoulli.h
@@ -93,6 +93,7 @@ void bernoulli_rev_next(fmpz_t numer, fmpz_t denom, bernoulli_rev_t iter);
void bernoulli_rev_clear(bernoulli_rev_t iter);
+void bernoulli_fmpq_vec_no_cache(fmpq * res, ulong a, slong num);
#define BERNOULLI_ENSURE_CACHED(n) \
do { \
diff --git a/bernoulli/cache_compute.c b/bernoulli/cache_compute.c
index b6a7c472..b114e4a6 100644
--- a/bernoulli/cache_compute.c
+++ b/bernoulli/cache_compute.c
@@ -31,43 +31,34 @@ bernoulli_cleanup(void)
void
bernoulli_cache_compute(slong n)
{
- if (bernoulli_cache_num < n)
+ slong old_num = bernoulli_cache_num;
+
+ if (old_num < n)
{
slong i, new_num;
- bernoulli_rev_t iter;
- if (bernoulli_cache_num == 0)
+ if (old_num == 0)
{
flint_register_cleanup_function(bernoulli_cleanup);
}
if (n <= 128)
- new_num = FLINT_MAX(bernoulli_cache_num + 32, n);
+ new_num = FLINT_MAX(old_num + 32, n);
else
- new_num = FLINT_MAX(bernoulli_cache_num + 128, n);
+ new_num = FLINT_MAX(old_num + 128, n);
bernoulli_cache = flint_realloc(bernoulli_cache, new_num * sizeof(fmpq));
- for (i = bernoulli_cache_num; i < new_num; i++)
+ for (i = old_num; i < new_num; i++)
fmpq_init(bernoulli_cache + i);
if (new_num <= 128)
{
+ /* todo: use recursion, but only compute new entries */
arith_bernoulli_number_vec(bernoulli_cache, new_num);
}
else
{
- i = new_num - 1;
- i -= (i % 2);
- bernoulli_rev_init(iter, i);
- for ( ; i >= bernoulli_cache_num; i -= 2)
- {
- bernoulli_rev_next(fmpq_numref(bernoulli_cache + i),
- fmpq_denref(bernoulli_cache + i), iter);
- }
- bernoulli_rev_clear(iter);
-
- if (new_num > 1)
- fmpq_set_si(bernoulli_cache + 1, -1, 2);
+ bernoulli_fmpq_vec_no_cache(bernoulli_cache + old_num, old_num, new_num - old_num);
}
bernoulli_cache_num = new_num;
diff --git a/bernoulli/fmpq_ui_multi_mod.c b/bernoulli/fmpq_ui_multi_mod.c
index 398fa741..218066e7 100644
--- a/bernoulli/fmpq_ui_multi_mod.c
+++ b/bernoulli/fmpq_ui_multi_mod.c
@@ -91,8 +91,9 @@ crt_basecase(crt_res_t * res, slong a, slong b, crt_args_t * args)
}
}
-static void
-tree_crt(fmpz_t r, fmpz_t m, mp_srcptr residues, mp_srcptr primes, slong len)
+/* todo: optimize basecase and move to flint */
+void
+_arb_tree_crt(fmpz_t r, fmpz_t m, mp_srcptr residues, mp_srcptr primes, slong len)
{
crt_res_t res;
crt_args_t args;
@@ -234,7 +235,7 @@ _bernoulli_fmpq_ui_multi_mod(fmpz_t num, fmpz_t den, ulong n, double alpha)
#endif
fmpz_init(M);
- tree_crt(num, M, residues, primes, num_primes);
+ _arb_tree_crt(num, M, residues, primes, num_primes);
fmpz_mul(num, num, den);
fmpz_mod(num, num, M);
diff --git a/bernoulli/fmpq_vec.c b/bernoulli/fmpq_vec.c
new file mode 100644
index 00000000..8474ee76
--- /dev/null
+++ b/bernoulli/fmpq_vec.c
@@ -0,0 +1,101 @@
+/*
+ Copyright (C) 2012 Fredrik Johansson
+
+ This file is part of Arb.
+
+ Arb is free software: you can redistribute it and/or modify it under
+ the terms of the GNU Lesser General Public License (LGPL) as published
+ by the Free Software Foundation; either version 2.1 of the License, or
+ (at your option) any later version. See .
+*/
+
+#include "bernoulli.h"
+
+static void
+bernoulli_vec_compute_one_thread(fmpq * res, slong a, slong b)
+{
+ slong i;
+ bernoulli_rev_t iter;
+
+ if (b <= a)
+ return;
+
+ /* Even indices */
+ i = b - 1;
+ i -= (i % 2);
+ bernoulli_rev_init(iter, i);
+ for ( ; i >= a; i -= 2)
+ bernoulli_rev_next(fmpq_numref(res + i - a), fmpq_denref(res + i - a), iter);
+ bernoulli_rev_clear(iter);
+
+ /* Odd indices */
+ for (i = b - 1 - (b % 2); i >= a; i -= 2)
+ {
+ if (i == 1)
+ fmpq_set_si(res + i - a, -1, 2);
+ else
+ fmpq_zero(res + i - a);
+ }
+}
+
+typedef struct
+{
+ fmpq * res;
+ slong a;
+ slong b;
+ slong block_size;
+ slong num_blocks;
+}
+work_chunk_t;
+
+static void
+worker(slong i, void * _work)
+{
+ work_chunk_t work = *((work_chunk_t *) _work);
+ slong a, b;
+
+ /* reverse strided scheduling */
+ i = work.num_blocks - 1 - i;
+
+ a = work.a + i * work.block_size;
+ b = FLINT_MIN(a + work.block_size, work.b);
+
+ bernoulli_vec_compute_one_thread(work.res + a - work.a, a, b);
+}
+
+void
+bernoulli_fmpq_vec_no_cache(fmpq * res, ulong a, slong num)
+{
+ if (a > (UWORD(1) << 31) || num > 1000000000)
+ {
+ flint_printf("bernoulli_fmpq_vec_no_cache: excessive input\n");
+ flint_abort();
+ }
+
+ if (a == 0 && num <= 128)
+ {
+ arith_bernoulli_number_vec(res, num);
+ return;
+ }
+
+ if (num < 200 || flint_get_num_threads() == 1)
+ {
+ bernoulli_vec_compute_one_thread(res, a, a + num);
+ }
+ else
+ {
+ slong num_blocks, block_size;
+ work_chunk_t work;
+
+ block_size = FLINT_MAX((a + num) / 32, 128);
+ num_blocks = (num + block_size - 1) / block_size;
+
+ work.res = res;
+ work.a = a;
+ work.b = a + num;
+ work.block_size = block_size;
+ work.num_blocks = num_blocks;
+
+ flint_parallel_do(worker, &work, num_blocks, -1, FLINT_PARALLEL_STRIDED);
+ }
+}
diff --git a/bernoulli/test/t-fmpq_vec.c b/bernoulli/test/t-fmpq_vec.c
new file mode 100644
index 00000000..105b087f
--- /dev/null
+++ b/bernoulli/test/t-fmpq_vec.c
@@ -0,0 +1,98 @@
+/*
+ Copyright (C) 2012 Fredrik Johansson
+
+ This file is part of Arb.
+
+ Arb is free software: you can redistribute it and/or modify it under
+ the terms of the GNU Lesser General Public License (LGPL) as published
+ by the Free Software Foundation; either version 2.1 of the License, or
+ (at your option) any later version. See .
+*/
+
+#include
+#include
+#include "bernoulli.h"
+#include "flint/ulong_extras.h"
+#include "flint/nmod_poly.h"
+#include "flint/nmod_vec.h"
+
+int main()
+{
+ slong iter;
+ flint_rand_t state;
+ slong n, bound;
+ mp_limb_t p, pinv, m1, m2;
+ nmod_poly_t A;
+
+ flint_printf("fmpq_vec....");
+ fflush(stdout);
+ flint_randinit(state);
+
+ bound = 1000 * FLINT_MIN(1.0, arb_test_multiplier());
+
+ p = n_nextprime(UWORD(1) << (FLINT_BITS - 1), 0);
+ pinv = n_preinvert_limb(p);
+
+ nmod_poly_init(A, p);
+ nmod_poly_set_coeff_ui(A, 1, 1);
+ nmod_poly_exp_series(A, A, bound);
+ nmod_poly_shift_right(A, A, 1);
+ nmod_poly_inv_series(A, A, bound);
+
+ m1 = 1;
+ for (n = 0; n < A->length; n++)
+ {
+ A->coeffs[n] = n_mulmod2_preinv(A->coeffs[n], m1, p, pinv);
+ m1 = n_mulmod2_preinv(m1, n + 1, p, pinv);
+ }
+
+ for (iter = 0; iter < 100 * arb_test_multiplier(); iter++)
+ {
+ slong a, b, num;
+ fmpq * res;
+ slong i;
+
+ b = n_randint(state, bound);
+ a = n_randint(state, b + 1);
+ num = b - a;
+
+ flint_set_num_threads(1 + n_randint(state, 4));
+
+ printf("a = %ld, b = %ld, num = %ld\n", a, b, num);
+
+ res = _fmpq_vec_init(num);
+
+ for (i = 0; i < num; i++)
+ fmpq_randtest(res + i, state, 100);
+
+ bernoulli_fmpq_vec_no_cache(res, a, num);
+
+ for (i = 0; i < num; i++)
+ {
+ m1 = fmpz_fdiv_ui(fmpq_numref(res + i), p);
+ m2 = fmpz_fdiv_ui(fmpq_denref(res + i), p);
+ m2 = n_invmod(m2, p);
+ m1 = n_mulmod2_preinv(m1, m2, p, pinv);
+ m2 = nmod_poly_get_coeff_ui(A, a + i);
+
+ if (m1 != m2)
+ {
+ flint_printf("FAIL:\n");
+ flint_printf("a = %wd, b = %wd, num = %wd, n = %wd\n", a, b, num, a + i);
+ flint_printf("m1 = %wu mod %wu\n", m1, p);
+ flint_printf("m2 = %wu mod %wu\n", m2, p);
+ flint_abort();
+ }
+ }
+
+ _fmpq_vec_clear(res, num);
+ }
+
+ nmod_poly_clear(A);
+
+ flint_randclear(state);
+ flint_cleanup_master();
+ flint_printf("PASS\n");
+ return EXIT_SUCCESS;
+}
+
diff --git a/doc/source/bernoulli.rst b/doc/source/bernoulli.rst
index b6e91fc8..89743527 100644
--- a/doc/source/bernoulli.rst
+++ b/doc/source/bernoulli.rst
@@ -58,6 +58,18 @@ Generation of Bernoulli numbers
Frees all memory allocated internally by *iter*.
+.. function:: void bernoulli_fmpq_vec_no_cache(fmpq * res, ulong a, slong num)
+
+ Writes *num* consecutive Bernoulli numbers to *res* starting
+ with `B_a`. This function is not currently optimized for a small
+ count *num*. The entries are not read from or written
+ to the Bernoulli number cache; if retrieving a vector of
+ Bernoulli numbers is needed more than once,
+ use :func:`bernoulli_cache_compute`
+ followed by :func:`bernoulli_fmpq_ui` instead.
+
+ This function is a wrapper for the *rev* iterators. It can use
+ multiple threads internally.
Caching
-------------------------------------------------------------------------------
@@ -74,6 +86,9 @@ Caching
Makes sure that the Bernoulli numbers up to at least `B_{n-1}` are cached.
Calling :func:`flint_cleanup()` frees the cache.
+ The cache is extended by calling :func:`bernoulli_fmpq_vec_no_cache`
+ internally.
+
Bounding
-------------------------------------------------------------------------------