Initial revision

1 files changed, 68 insertions, 0 deletions

diff --git a/mpz/tdiv_q_2exp.c b/mpz/tdiv_q_2exp.c
new file mode 100644
index 000000000..e70d810e7
--- /dev/null
+++ b/mpz/tdiv_q_2exp.c
@@ -0,0 +1,68 @@
+/* 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 Library General Public License as published by
+the Free Software Foundation; either version 2 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 Library General Public
+License for more details.
+
+You should have received a copy of the GNU Library 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;
+    }
+}