1 files changed, 83 insertions, 0 deletions
diff --git a/gnu/lib/libgmp/mpn_lshift.c b/gnu/lib/libgmp/mpn_lshift.c
new file mode 100644
index 0000000..b89a736
--- /dev/null
+++ b/gnu/lib/libgmp/mpn_lshift.c
@@ -0,0 +1,83 @@
+/* mpn_lshift -- Shift left low level.
+
+Copyright (C) 1991 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 General Public License as published by
+the Free Software Foundation; either version 2, 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 General Public License for more details.
+
+You should have received a copy of the GNU General Public License
+along with the GNU MP Library; see the file COPYING.  If not, write to
+the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA.  */
+
+#include "gmp.h"
+#include "gmp-impl.h"
+
+/* Shift U (pointed to by UP and USIZE digits long) CNT bits to the left
+   and store the USIZE least significant digits of the result at WP.
+   Return the bits shifted out from the most significant digit.
+
+   Argument constraints:
+   0. U must be normalized (i.e. it's most significant digit != 0).
+   1. 0 <= CNT < BITS_PER_MP_LIMB
+   2. If the result is to be written over the input, WP must be >= UP.
+*/
+
+mp_limb
+#ifdef __STDC__
+mpn_lshift (mp_ptr wp,
+	    mp_srcptr up, mp_size usize,
+	    unsigned cnt)
+#else
+mpn_lshift (wp, up, usize, cnt)
+     mp_ptr wp;
+     mp_srcptr up;
+     mp_size usize;
+     unsigned cnt;
+#endif
+{
+  mp_limb high_limb, low_limb;
+  unsigned sh_1, sh_2;
+  mp_size i;
+  mp_limb retval;
+
+  if (usize == 0)
+    return 0;
+
+  sh_1 = cnt;
+  if (sh_1 == 0)
+    {
+      if (wp != up)
+	{
+	  /* Copy from high end to low end, to allow specified input/output
+	     overlapping.  */
+	  for (i = usize - 1; i >= 0; i--)
+	    wp[i] = up[i];
+	}
+      return 0;
+    }
+
+  wp += 1;
+  sh_2 = BITS_PER_MP_LIMB - sh_1;
+  i = usize - 1;
+  low_limb = up[i];
+  retval = low_limb >> sh_2;
+  high_limb = low_limb;
+  while (--i >= 0)
+    {
+      low_limb = up[i];
+      wp[i] = (high_limb << sh_1) | (low_limb >> sh_2);
+      high_limb = low_limb;
+    }
+  wp[i] = high_limb << sh_1;
+
+  return retval;
+}