X-Git-Url: https://oss.titaniummirror.com/gitweb?a=blobdiff_plain;f=gmp%2Fmpz%2Ftdiv_r_2exp.c;fp=gmp%2Fmpz%2Ftdiv_r_2exp.c;h=951b75d419bea3140e044bbb24a232d2a86ad2b2;hb=6fed43773c9b0ce596dca5686f37ac3fc0fa11c0;hp=0000000000000000000000000000000000000000;hpb=27b11d56b743098deb193d510b337ba22dc52e5c;p=msp430-gcc.git diff --git a/gmp/mpz/tdiv_r_2exp.c b/gmp/mpz/tdiv_r_2exp.c new file mode 100644 index 00000000..951b75d4 --- /dev/null +++ b/gmp/mpz/tdiv_r_2exp.c @@ -0,0 +1,70 @@ +/* mpz_tdiv_r_2exp -- Divide a integer by 2**CNT and produce a remainder. + +Copyright 1991, 1993, 1994, 1995, 2001, 2002 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 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. + +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 Lesser General Public +License for more details. + +You should have received a copy of the GNU Lesser General Public License +along with the GNU MP Library. If not, see http://www.gnu.org/licenses/. */ + +#include "gmp.h" +#include "gmp-impl.h" + +void +mpz_tdiv_r_2exp (mpz_ptr res, mpz_srcptr in, unsigned long int cnt) +{ + mp_size_t in_size = ABS (in->_mp_size); + mp_size_t res_size; + mp_size_t limb_cnt = cnt / GMP_NUMB_BITS; + mp_srcptr in_ptr = in->_mp_d; + + 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; + if (res->_mp_alloc < res_size) + _mpz_realloc (res, res_size); + + res->_mp_d[limb_cnt] = x; + } + else + { + res_size = limb_cnt; + MPN_NORMALIZE (in_ptr, res_size); + + if (res->_mp_alloc < res_size) + _mpz_realloc (res, res_size); + + limb_cnt = res_size; + } + } + 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. */ + res_size = in_size; + if (res->_mp_alloc < res_size) + _mpz_realloc (res, res_size); + + limb_cnt = res_size; + } + + if (res != in) + MPN_COPY (res->_mp_d, in->_mp_d, limb_cnt); + res->_mp_size = in->_mp_size >= 0 ? res_size : -res_size; +}