[Gmp-commit] /var/hg/gmp: 3 new changesets
mercurial at gmplib.org
mercurial at gmplib.org
Sat Dec 30 13:25:40 UTC 2017
details: /var/hg/gmp/rev/f8f873f321d4
changeset: 17514:f8f873f321d4
user: Marco Bodrato <bodrato at mail.dm.unipi.it>
date: Sat Dec 30 13:44:10 2017 +0100
description:
mpz/bin_ui.c: Rewrite, using Fredrik Johansson's suggestions
details: /var/hg/gmp/rev/c09527a98b94
changeset: 17515:c09527a98b94
user: Marco Bodrato <bodrato at mail.dm.unipi.it>
date: Sat Dec 30 14:17:48 2017 +0100
description:
mini-gmp/mini-gmp.[ch]: new functions: mpz_2fac_ui and mpz_mfac_uiui
details: /var/hg/gmp/rev/570604eb878d
changeset: 17516:570604eb878d
user: Marco Bodrato <bodrato at mail.dm.unipi.it>
date: Sat Dec 30 14:25:20 2017 +0100
description:
Changelog
diffstat:
ChangeLog | 4 +
mini-gmp/ChangeLog | 6 +
mini-gmp/mini-gmp.c | 21 +++-
mini-gmp/mini-gmp.h | 4 +-
mpz/bin_ui.c | 224 ++++++++++++++++++++++++++++++++++++++++-----------
5 files changed, 203 insertions(+), 56 deletions(-)
diffs (truncated from 368 to 300 lines):
diff -r 918aa348b43e -r 570604eb878d ChangeLog
--- a/ChangeLog Wed Dec 27 18:03:41 2017 +0100
+++ b/ChangeLog Sat Dec 30 14:25:20 2017 +0100
@@ -1,3 +1,7 @@
+2017-12-30 Marco Bodrato <bodrato at mail.dm.unipi.it>
+
+ * mpz/bin_ui.c: Rewrite, using Fredrik Johansson's suggestions.
+
2017-12-27 Niels Möller <nisse at lysator.liu.se>
* longlong.h (arm32/arm64): Leave COUNT_LEADING_ZEROS_0 undefined,
diff -r 918aa348b43e -r 570604eb878d mini-gmp/ChangeLog
--- a/mini-gmp/ChangeLog Wed Dec 27 18:03:41 2017 +0100
+++ b/mini-gmp/ChangeLog Sat Dec 30 14:25:20 2017 +0100
@@ -1,3 +1,9 @@
+2017-12-30 Marco Bodrato <bodrato at mail.dm.unipi.it>
+
+ * mini-gmp.c (mpz_mfac_ui, mpz_2fac_ui): New functions.
+ * mini-gmp.h: Declare them.
+ * mini-gmp.c (mpz_fac_ui): Use mpz_mfac_ui.
+
2017-07-23 Niels Möller <nisse at lysator.liu.se>
* mini-gmp.c (GMP_MPN_OVERLAP_P): New macro, copy of
diff -r 918aa348b43e -r 570604eb878d mini-gmp/mini-gmp.c
--- a/mini-gmp/mini-gmp.c Wed Dec 27 18:03:41 2017 +0100
+++ b/mini-gmp/mini-gmp.c Sat Dec 30 14:25:20 2017 +0100
@@ -3352,11 +3352,24 @@
/* Combinatorics */
void
+mpz_mfac_uiui (mpz_t x, unsigned long n, unsigned long m)
+{
+ mpz_set_ui (x, n + (n == 0));
+ if (m + 1 < 2) return;
+ while (n > m + 1)
+ mpz_mul_ui (x, x, n -= m);
+}
+
+void
+mpz_2fac_ui (mpz_t x, unsigned long n)
+{
+ mpz_mfac_uiui (x, n, 2);
+}
+
+void
mpz_fac_ui (mpz_t x, unsigned long n)
{
- mpz_set_ui (x, n + (n == 0));
- while (n > 2)
- mpz_mul_ui (x, x, --n);
+ mpz_mfac_uiui (x, n, 1);
}
void
@@ -3372,7 +3385,7 @@
mpz_init (t);
mpz_fac_ui (t, k);
- for (; k > 0; k--)
+ for (; k > 0; --k)
mpz_mul_ui (r, r, n--);
mpz_divexact (r, r, t);
diff -r 918aa348b43e -r 570604eb878d mini-gmp/mini-gmp.h
--- a/mini-gmp/mini-gmp.h Wed Dec 27 18:03:41 2017 +0100
+++ b/mini-gmp/mini-gmp.h Sat Dec 30 14:25:20 2017 +0100
@@ -1,6 +1,6 @@
/* mini-gmp, a minimalistic implementation of a GNU GMP subset.
-Copyright 2011-2015 Free Software Foundation, Inc.
+Copyright 2011-2015, 2017 Free Software Foundation, Inc.
This file is part of the GNU MP Library.
@@ -217,6 +217,8 @@
int mpz_root (mpz_t, const mpz_t, unsigned long);
void mpz_fac_ui (mpz_t, unsigned long);
+void mpz_2fac_ui (mpz_t, unsigned long);
+void mpz_mfac_uiui (mpz_t, unsigned long, unsigned long);
void mpz_bin_uiui (mpz_t, unsigned long, unsigned long);
int mpz_probab_prime_p (const mpz_t, int);
diff -r 918aa348b43e -r 570604eb878d mpz/bin_ui.c
--- a/mpz/bin_ui.c Wed Dec 27 18:03:41 2017 +0100
+++ b/mpz/bin_ui.c Sat Dec 30 14:25:20 2017 +0100
@@ -1,6 +1,6 @@
-/* mpz_bin_ui - compute n over k.
+/* mpz_bin_ui(RESULT, N, K) -- Set RESULT to N over K.
-Copyright 1998-2002, 2012, 2013, 2015 Free Software Foundation, Inc.
+Copyright 1998-2002, 2012, 2013, 2015, 2017 Free Software Foundation, Inc.
This file is part of the GNU MP Library.
@@ -29,8 +29,116 @@
see https://www.gnu.org/licenses/. */
#include "gmp-impl.h"
-#include "longlong.h"
+/* How many special cases? Minimum is 2: 0 and 1;
+ * also 3 {0,1,2} and 5 {0,1,2,3,4} are implemented.
+ */
+#define APARTA_KALKULOJ 2
+
+/* Whether to use (1) or not (0) the function mpz_bin_uiui whenever
+ * the operands fit.
+ */
+#define UZU_BIN_UIUI 0
+
+static void
+posmpz_init (mpz_ptr r)
+{
+ mp_ptr rp;
+ ASSERT (SIZ (r) > 0);
+ rp = SIZ (r) + MPZ_REALLOC (r, SIZ (r) + 2);
+ *rp = 0;
+ *++rp = 0;
+}
+
+/* Equivalent to mpz_add_ui (r, r, in), but faster when
+ 0 < SIZ (r) < ALLOC (r) and limbs above SIZ (r) contain 0. */
+static void
+posmpz_inc_ui (mpz_ptr r, mp_limb_t in)
+{
+ ASSERT (SIZ (r) > 0);
+ MPN_INCR_U (PTR (r), SIZ (r) + 1, in);
+ SIZ (r) += (PTR (r)[SIZ (r)] != 0);
+}
+
+static void
+rek_raising_fac (mpz_ptr r, mpz_ptr n, unsigned long int k, unsigned long int lk, mpz_ptr t1, mpz_ptr t2)
+{
+ /* Should the threshold depend on SIZ (n) ? */
+ if (k - lk < 10)
+ {
+ do {
+ posmpz_inc_ui (n, k);
+ mpz_mul (r, r, n);
+ --k;
+ } while (k > lk);
+ }
+ else
+ {
+ mpz_t t3;
+ unsigned long int m;
+
+ m = (k + lk) >> 1;
+ rek_raising_fac (r, n, k, m, t1, t2);
+
+ posmpz_inc_ui (n, m);
+ if (t1 == NULL)
+ {
+ mpz_init_set (t3, n);
+ t1 = t3;
+ }
+ else
+ {
+ ALLOC (t3) = 0;
+ mpz_set (t1, n);
+ }
+ rek_raising_fac (t1, n, m - 1, lk, t2, NULL);
+
+ mpz_mul (r, r, t1);
+ mpz_clear (t3);
+ }
+}
+
+/* Computes (n+1)(n+2)...(n+k)/2^(k/2) using the helper function
+ rek_raising_fac, and exploiting an idea inspired by piece of code
+ that Fredrik Johansson wrote.
+
+ Force an even k = 2i then compute:
+ p = (n+1)(n+2i)/2
+ i' = i - 1
+ p == (n+1)(n+2i'+2)/2
+ p' = p + i' == (n+2)(n+2i'+1)/2
+ n' = n + 1
+ p'== (n'+1)(n'+2i')/2 == (n+1 +1)(n+2i -1)/2
+
+ And compute the product p * p' * p" ...
+ */
+static void
+mpz_raising_fac (mpz_ptr r, mpz_ptr n, unsigned long int k, mpz_ptr t, mpz_ptr p)
+{
+ ASSERT (k > 1);
+ mpz_add_ui (t, n, k);
+ mpz_add_ui (n, n, 1);
+ mpz_mul (p, n, t);
+
+ if ((k & 1) != 0)
+ {
+ mpz_sub (p, p, n);
+ mpz_fdiv_q_2exp (p, p, 1);
+ mpz_mul (r, t, p);
+ }
+ else
+ {
+ mpz_fdiv_q_2exp (p, p, 1);
+ mpz_set (r, p);
+ }
+
+ if ((APARTA_KALKULOJ > 3) || (k > 3))
+ {
+ k = (k >> 1) - 1;
+ posmpz_init (p);
+ rek_raising_fac (r, p, k, 0, t, n);
+ }
+}
/* This is a poor implementation. Look at bin_uiui.c for improvement ideas.
In fact consider calling mpz_bin_uiui() when the arguments fit, leaving
@@ -39,27 +147,16 @@
The identity bin(n,k) = (-1)^k * bin(-n+k-1,k) can be found in Knuth vol
1 section 1.2.6 part G. */
-
-#define DIVIDE() \
- do { \
- ASSERT (SIZ(r) > 0); \
- MPN_DIVREM_OR_DIVEXACT_1 (PTR(r), PTR(r), (mp_size_t) SIZ(r), kacc); \
- SIZ(r) -= (PTR(r)[SIZ(r)-1] == 0); \
- } while (0)
-
void
mpz_bin_ui (mpz_ptr r, mpz_srcptr n, unsigned long int k)
{
- mpz_t ni;
mp_limb_t i;
- mpz_t nacc;
- mp_limb_t kacc;
+ mpz_t ni = MPZ_ROINIT_N (&i, 0);
mp_size_t negate;
if (SIZ (n) < 0)
{
/* bin(n,k) = (-1)^k * bin(-n+k-1,k), and set ni = -n+k-1 - k = -n-1 */
- mpz_init (ni);
mpz_add_ui (ni, n, 1L);
mpz_neg (ni, ni);
negate = (k & 1); /* (-1)^k */
@@ -75,14 +172,12 @@
}
/* set ni = n-k */
- mpz_init (ni);
mpz_sub_ui (ni, n, k);
negate = 0;
}
/* Now wanting bin(ni+k,k), with ni positive, and "negate" is the sign (0
for positive, 1 for negative). */
- SIZ (r) = 1; MPZ_NEWALLOC (r, 1)[0] = 1;
/* Rewrite bin(n,k) as bin(n,n-k) if that is smaller. In this case it's
whether ni+k-k < k meaning ni<k, and if so change to denominator ni+k-k
@@ -95,48 +190,75 @@
mpz_set_ui (ni, tmp);
}
- kacc = 1;
- mpz_init_set_ui (nacc, 1L);
-
- for (i = 1; i <= k; i++)
+ if (k < APARTA_KALKULOJ)
{
- mp_limb_t k1, k0;
-
-#if 0
- mp_limb_t nacclow;
- int c;
-
- nacclow = PTR(nacc)[0];
- for (c = 0; (((kacc | nacclow) & 1) == 0); c++)
+ if (k == 0)
{
- kacc >>= 1;
- nacclow >>= 1;
+ SIZ (r) = 1;
+ MPZ_NEWALLOC (r, 1)[0] = 1;
}
- mpz_div_2exp (nacc, nacc, c);
-#endif
-
- mpz_add_ui (ni, ni, 1L);
- mpz_mul (nacc, nacc, ni);
- umul_ppmm (k1, k0, kacc, i << GMP_NAIL_BITS);
- if (k1 != 0)
+#if APARTA_KALKULOJ == 3 || APARTA_KALKULOJ == 5
+ else if (k == 2)
{
- /* Accumulator overflow. Perform bignum step. */
- mpz_mul (r, r, nacc);
- SIZ (nacc) = 1; PTR (nacc)[0] = 1;
- DIVIDE ();
- kacc = i;
+ mpz_add_ui (ni, ni, 1);
+ mpz_mul (r, ni, ni);
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