e554550755
for file in $(find -name \*.h ) ; do sed -e "s/#include \"gmp\.h\"/#include \"mpir.h\"/g" $file > temp ; mv temp $file ; done for file in $(find -name \*.cc) ; do sed -e "s/#include \"gmp\.h\"/#include \"mpir.h\"/g" $file > temp ; mv temp $file ; done
105 lines
2.8 KiB
C
105 lines
2.8 KiB
C
/* mpz_cdiv_q_2exp, mpz_fdiv_q_2exp -- quotient from mpz divided by 2^n.
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Copyright 1991, 1993, 1994, 1996, 1998, 1999, 2001, 2002, 2004 Free Software
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Foundation, Inc.
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This file is part of the GNU MP Library.
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The GNU MP Library is free software; you can redistribute it and/or modify
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it under the terms of the GNU Lesser General Public License as published by
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the Free Software Foundation; either version 2.1 of the License, or (at your
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option) any later version.
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The GNU MP Library is distributed in the hope that it will be useful, but
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WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
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or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public
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License for more details.
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You should have received a copy of the GNU Lesser General Public License
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along with the GNU MP Library; see the file COPYING.LIB. If not, write to
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the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston,
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MA 02110-1301, USA. */
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#include "mpir.h"
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#include "gmp-impl.h"
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/* dir==1 for ceil, dir==-1 for floor */
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static void __gmpz_cfdiv_q_2exp _PROTO ((REGPARM_3_1 (mpz_ptr w, mpz_srcptr u, unsigned long cnt, int dir))) REGPARM_ATTR (1);
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#define cfdiv_q_2exp(w,u,cnt,dir) __gmpz_cfdiv_q_2exp (REGPARM_3_1 (w,u,cnt,dir))
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REGPARM_ATTR (1) static void
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cfdiv_q_2exp (mpz_ptr w, mpz_srcptr u, unsigned long cnt, int dir)
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{
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mp_size_t wsize, usize, abs_usize, limb_cnt, i;
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mp_srcptr up;
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mp_ptr wp;
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mp_limb_t round, rmask;
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usize = SIZ (u);
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abs_usize = ABS (usize);
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limb_cnt = cnt / GMP_NUMB_BITS;
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wsize = abs_usize - limb_cnt;
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if (wsize <= 0)
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{
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/* u < 2**cnt, so result 1, 0 or -1 according to rounding */
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PTR(w)[0] = 1;
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SIZ(w) = (usize == 0 || (usize ^ dir) < 0 ? 0 : dir);
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return;
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}
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/* +1 limb to allow for mpn_add_1 below */
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MPZ_REALLOC (w, wsize+1);
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/* Check for rounding if direction matches u sign.
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Set round if we're skipping non-zero limbs. */
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up = PTR(u);
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round = 0;
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rmask = ((usize ^ dir) >= 0 ? MP_LIMB_T_MAX : 0);
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if (rmask != 0)
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for (i = 0; i < limb_cnt && round == 0; i++)
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round = up[i];
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wp = PTR(w);
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cnt %= GMP_NUMB_BITS;
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if (cnt != 0)
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{
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round |= rmask & mpn_rshift (wp, up + limb_cnt, wsize, cnt);
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wsize -= (wp[wsize - 1] == 0);
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}
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else
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MPN_COPY_INCR (wp, up + limb_cnt, wsize);
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if (round != 0)
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{
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if (wsize != 0)
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{
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mp_limb_t cy;
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cy = mpn_add_1 (wp, wp, wsize, CNST_LIMB(1));
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wp[wsize] = cy;
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wsize += cy;
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}
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else
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{
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/* We shifted something to zero. */
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wp[0] = 1;
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wsize = 1;
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}
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}
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SIZ(w) = (usize >= 0 ? wsize : -wsize);
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}
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void
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mpz_cdiv_q_2exp (mpz_ptr w, mpz_srcptr u, unsigned long cnt)
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{
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cfdiv_q_2exp (w, u, cnt, 1);
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}
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void
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mpz_fdiv_q_2exp (mpz_ptr w, mpz_srcptr u, unsigned long cnt)
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{
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cfdiv_q_2exp (w, u, cnt, -1);
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}
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