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Diffstat (limited to 'vendor/gmp-6.3.0/mpz/primorial_ui.c')
| -rw-r--r-- | vendor/gmp-6.3.0/mpz/primorial_ui.c | 131 |
1 files changed, 131 insertions, 0 deletions
diff --git a/vendor/gmp-6.3.0/mpz/primorial_ui.c b/vendor/gmp-6.3.0/mpz/primorial_ui.c new file mode 100644 index 0000000..b1176c7 --- /dev/null +++ b/vendor/gmp-6.3.0/mpz/primorial_ui.c @@ -0,0 +1,131 @@ +/* mpz_primorial_ui(RES, N) -- Set RES to N# the product of primes <= N. + +Contributed to the GNU project by Marco Bodrato. + +Copyright 2012, 2015, 2016, 2021 Free Software Foundation, Inc. + +This file is part of the GNU MP Library. + +The GNU MP Library is free software; you can redistribute it and/or modify +it under the terms of either: + + * the GNU Lesser General Public License as published by the Free + Software Foundation; either version 3 of the License, or (at your + option) any later version. + +or + + * the GNU General Public License as published by the Free Software + Foundation; either version 2 of the License, or (at your option) any + later version. + +or both in parallel, as here. + +The GNU MP Library is distributed in the hope that it will be useful, but +WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY +or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License +for more details. + +You should have received copies of the GNU General Public License and the +GNU Lesser General Public License along with the GNU MP Library. If not, +see https://www.gnu.org/licenses/. */ + +#include "gmp-impl.h" + +/* TODO: Remove duplicated constants / macros / static functions... + */ + +/*************************************************************/ +/* Section macros: common macros, for swing/fac/bin (&sieve) */ +/*************************************************************/ + +#define FACTOR_LIST_STORE(P, PR, MAX_PR, VEC, I) \ + do { \ + if ((PR) > (MAX_PR)) { \ + (VEC)[(I)++] = (PR); \ + (PR) = (P); \ + } else \ + (PR) *= (P); \ + } while (0) + +/*********************************************************/ +/* Section sieve: sieving functions and tools for primes */ +/*********************************************************/ + +#if WANT_ASSERT +/* n_to_bit (n) = ((n-1)&(-CNST_LIMB(2)))/3U-1 */ +static mp_limb_t +n_to_bit (mp_limb_t n) { return ((n-5)|1)/3U; } + +static mp_size_t +primesieve_size (mp_limb_t n) { return n_to_bit(n) / GMP_LIMB_BITS + 1; } +#endif + +/*********************************************************/ +/* Section primorial: implementation */ +/*********************************************************/ + +void +mpz_primorial_ui (mpz_ptr res, unsigned long n) +{ + ASSERT (n <= GMP_NUMB_MAX); + + if (n < 5) + { + /* The smallest 5 results for primorial are stored */ + /* in a 15-bits constant (five octal digits) */ + MPZ_NEWALLOC (res, 1)[0] = (066211 >> (n * 3)) & 7; + SIZ (res) = 1; + } + else + { + mp_limb_t *sieve, *factors; + mp_size_t size, j; + mp_limb_t prod; + TMP_DECL; + + /* Try to estimate the result size, to avoid */ + /* resizing, and to initially store the sieve. */ + size = n / GMP_NUMB_BITS; + size = size + (size >> 1) + 1; + ASSERT (size >= primesieve_size (n)); + sieve = MPZ_NEWALLOC (res, size); + size = (gmp_primesieve (sieve, n) + 1) / log_n_max (n) + 1; + + TMP_MARK; + factors = TMP_ALLOC_LIMBS (size); + + j = 0; + + prod = 6; + + /* Store primes from 5 to n */ + { + mp_limb_t max_prod; + + max_prod = GMP_NUMB_MAX / n; + + /* Loop on sieved primes. */ + for (mp_limb_t i = 4, *sp = sieve; i < n; i += GMP_LIMB_BITS * 3) + for (mp_limb_t b = i, x = ~ *(sp++); x != 0; b += 3, x >>= 1) + if (x & 1) + { + mp_limb_t prime = b | 1; + FACTOR_LIST_STORE (prime, prod, max_prod, factors, j); + } + } + + if (j != 0) + { + factors[j++] = prod; + mpz_prodlimbs (res, factors, j); + } + else + { + PTR (res)[0] = prod; + SIZ (res) = 1; + } + + TMP_FREE; + } +} |