diff options
Diffstat (limited to 'vendor/gmp-6.3.0/mpz/tdiv_r_2exp.c')
-rw-r--r-- | vendor/gmp-6.3.0/mpz/tdiv_r_2exp.c | 76 |
1 files changed, 76 insertions, 0 deletions
diff --git a/vendor/gmp-6.3.0/mpz/tdiv_r_2exp.c b/vendor/gmp-6.3.0/mpz/tdiv_r_2exp.c new file mode 100644 index 0000000..96a81f7 --- /dev/null +++ b/vendor/gmp-6.3.0/mpz/tdiv_r_2exp.c @@ -0,0 +1,76 @@ +/* mpz_tdiv_r_2exp -- Divide an integer by 2**CNT and produce a remainder. + +Copyright 1991, 1993-1995, 2001, 2002, 2012 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" + +void +mpz_tdiv_r_2exp (mpz_ptr res, mpz_srcptr in, mp_bitcnt_t cnt) +{ + mp_size_t in_size = ABSIZ (in); + mp_size_t res_size; + mp_size_t limb_cnt = cnt / GMP_NUMB_BITS; + mp_srcptr in_ptr = PTR (in); + + if (in_size > limb_cnt) + { + /* The input operand is (probably) greater than 2**CNT. */ + mp_limb_t x; + + x = in_ptr[limb_cnt] & (((mp_limb_t) 1 << cnt % GMP_NUMB_BITS) - 1); + if (x != 0) + { + res_size = limb_cnt + 1; + MPZ_REALLOC (res, res_size); + + PTR (res)[limb_cnt] = x; + } + else + { + MPN_NORMALIZE (in_ptr, limb_cnt); + + MPZ_REALLOC (res, limb_cnt); + + res_size = limb_cnt; + } + } + else + { + /* The input operand is smaller than 2**CNT. We perform a no-op, + apart from that we might need to copy IN to RES. */ + limb_cnt = in_size; + MPZ_REALLOC (res, limb_cnt); + + res_size = limb_cnt; + } + + if (res != in) + MPN_COPY (PTR (res), PTR (in), limb_cnt); + SIZ (res) = SIZ (in) >= 0 ? res_size : -res_size; +} |