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| author | Marco Bodrato <bodrato@mail.dm.unipi.it> | 2012-04-17 08:02:34 +0200 |
|---|---|---|
| committer | Marco Bodrato <bodrato@mail.dm.unipi.it> | 2012-04-17 08:02:34 +0200 |
| commit | 3a5fd656ba354687c2c3f7e8a30cbfed3381a30c (patch) | |
| tree | b5f8692f93ec17b2825bc3f5768ca1abc3baace7 /mpz/bin_uiui.c | |
| parent | 29562d58a1a2d7fc2f40a45416b9240a4b6e0996 (diff) | |
| download | gmp-3a5fd656ba354687c2c3f7e8a30cbfed3381a30c.tar.gz | |
mpz/bin_uiui.c: Support small limbs (fallback on bin_ui).
Diffstat (limited to 'mpz/bin_uiui.c')
| -rw-r--r-- | mpz/bin_uiui.c | 15 |
1 files changed, 14 insertions, 1 deletions
diff --git a/mpz/bin_uiui.c b/mpz/bin_uiui.c index e99188f5e..82943e4f0 100644 --- a/mpz/bin_uiui.c +++ b/mpz/bin_uiui.c @@ -346,6 +346,9 @@ mpz_smallk_bin_uiui (mpz_ptr r, unsigned long int n, unsigned long int k) mpn_pi1_bdiv_q_1 (rp, rp, rn, fac[k], facinv[k - 2], fac2cnt[k / 2 - 1] - i2cnt); + /* A two-fold, branch-free normalisation is possible :*/ + /* rn -= rp[rn - 1] == 0; */ + /* rn -= rp[rn - 1] == 0; */ MPN_NORMALIZE_NOT_ZERO (rp, rn); SIZ(r) = rn; @@ -426,17 +429,27 @@ mpz_smallkdc_bin_uiui (mpz_ptr r, unsigned long int n, unsigned long int k) mpn_pi1_bdiv_q_1 (rp, rp, rn, bin2kk[k - ODD_CENTRAL_BINOMIAL_OFFSET], bin2kkinv[k - ODD_CENTRAL_BINOMIAL_OFFSET], fac2bin[k - ODD_CENTRAL_BINOMIAL_OFFSET] - (k != hk)); + /* A two-fold, branch-free normalisation is possible :*/ + /* rn -= rp[rn - 1] == 0; */ + /* rn -= rp[rn - 1] == 0; */ MPN_NORMALIZE_NOT_ZERO (rp, rn); SIZ(r) = rn; } -/* WARNING: it assumes that n fits in a limb! */ void mpz_bin_uiui (mpz_ptr r, unsigned long int n, unsigned long int k) { if (UNLIKELY (n < k)) { SIZ (r) = 0; +#if BITS_PER_ULONG > GMP_NUMB_BITS + } else if (UNLIKELY (n > GMP_NUMB_MAX)) { + mpz_t tmp; + + mpz_init_set_ui (tmp, n); + mpz_bin_ui (r, tmp, k); + mpz_clear (tmp); +#endif } else { ASSERT (n <= GMP_NUMB_MAX); /* Rewrite bin(n,k) as bin(n,n-k) if that is smaller. */ |