Imported gcc-4.4.3

[msp430-gcc.git] / gmp / mpz / tdiv_r_2exp.c

diff --git a/gmp/mpz/tdiv_r_2exp.c b/gmp/mpz/tdiv_r_2exp.c
new file mode 100644 (file)
index 0000000..951b75d
--- /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;
+}