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Diffstat (limited to 'rts/gmp/mpz/tdiv_q_2exp.c')
-rw-r--r--rts/gmp/mpz/tdiv_q_2exp.c68
1 files changed, 68 insertions, 0 deletions
diff --git a/rts/gmp/mpz/tdiv_q_2exp.c b/rts/gmp/mpz/tdiv_q_2exp.c
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+++ b/rts/gmp/mpz/tdiv_q_2exp.c
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+/* mpz_tdiv_q_2exp -- Divide an integer by 2**CNT. Round the quotient
+ towards -infinity.
+
+Copyright (C) 1991, 1993, 1994, 1996 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 2.1 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; see the file COPYING.LIB. If not, write to
+the Free Software Foundation, Inc., 59 Temple Place - Suite 330, Boston,
+MA 02111-1307, USA. */
+
+#include "gmp.h"
+#include "gmp-impl.h"
+
+void
+#if __STDC__
+mpz_tdiv_q_2exp (mpz_ptr w, mpz_srcptr u, unsigned long int cnt)
+#else
+mpz_tdiv_q_2exp (w, u, cnt)
+ mpz_ptr w;
+ mpz_srcptr u;
+ unsigned long int cnt;
+#endif
+{
+ mp_size_t usize, wsize;
+ mp_size_t limb_cnt;
+
+ usize = u->_mp_size;
+ limb_cnt = cnt / BITS_PER_MP_LIMB;
+ wsize = ABS (usize) - limb_cnt;
+ if (wsize <= 0)
+ w->_mp_size = 0;
+ else
+ {
+ mp_ptr wp;
+ mp_srcptr up;
+
+ if (w->_mp_alloc < wsize)
+ _mpz_realloc (w, wsize);
+
+ wp = w->_mp_d;
+ up = u->_mp_d;
+
+ cnt %= BITS_PER_MP_LIMB;
+ if (cnt != 0)
+ {
+ mpn_rshift (wp, up + limb_cnt, wsize, cnt);
+ wsize -= wp[wsize - 1] == 0;
+ }
+ else
+ {
+ MPN_COPY_INCR (wp, up + limb_cnt, wsize);
+ }
+
+ w->_mp_size = usize >= 0 ? wsize : -wsize;
+ }
+}