Imported gcc-4.4.3

[msp430-gcc.git] / gmp / mpn / generic / bdiv_dbm1c.c

diff --git a/gmp/mpn/generic/bdiv_dbm1c.c b/gmp/mpn/generic/bdiv_dbm1c.c
new file mode 100644 (file)
index 0000000..23cb6f1
--- /dev/null
+++ b/gmp/mpn/generic/bdiv_dbm1c.c
@@ -0,0 +1,48 @@
+/* mpn_bdiv_dbm1c -- divide an mpn number by a divisor of B-1, where B is the
+   limb base.  The dbm1c moniker means "Divisor of B Minus 1 with Carry".
+
+   THE FUNCTION IN THIS FILE IS INTERNAL WITH A MUTABLE INTERFACE.  IT IS ONLY
+   SAFE TO REACH IT THROUGH DOCUMENTED INTERFACES.  IN FACT, IT IS ALMOST
+   GUARANTEED THAT IT'LL CHANGE OR DISAPPEAR IN A FUTURE GNU MP RELEASE.
+
+Copyright 2008, 2009 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"
+#include "longlong.h"
+
+
+mp_limb_t
+mpn_bdiv_dbm1c (mp_ptr qp, mp_srcptr ap, mp_size_t n, mp_limb_t bd, mp_limb_t h)
+{
+  mp_limb_t a, p0, p1, cy;
+  mp_size_t i;
+
+  for (i = 0; i < n; i++)
+    {
+      a = ap[i];
+      umul_ppmm (p1, p0, a, bd << GMP_NAIL_BITS);
+      p0 >>= GMP_NAIL_BITS;
+      cy = h < p0;
+      h = (h - p0) & GMP_NUMB_MASK;
+      qp[i] = h;
+      h = h - p1 - cy;
+    }
+
+  return h;
+}