1 files changed, 133 insertions, 0 deletions
diff --git a/grub-core/lib/libgcrypt/mpi/generic/udiv-w-sdiv.c b/grub-core/lib/libgcrypt/mpi/generic/udiv-w-sdiv.c
new file mode 100644
index 0000000..e80d98b
--- /dev/null
+++ b/grub-core/lib/libgcrypt/mpi/generic/udiv-w-sdiv.c
@@ -0,0 +1,133 @@
+/* mpih-w-sdiv -- implement udiv_qrnnd on machines with only signed
+ *	      	  division.
+ * Copyright (C) 1992, 1994, 1996, 1998, 2002 Free Software Foundation, Inc.
+ * Contributed by Peter L. Montgomery.
+ *
+ * This file is part of Libgcrypt.
+ *
+ * Libgcrypt 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.
+ *
+ * Libgcrypt 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 this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA
+ */
+
+#include <config.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include "mpi-internal.h"
+#include "longlong.h"
+
+
+#if 0  /* not yet ported to MPI */
+
+mpi_limb_t
+mpihelp_udiv_w_sdiv( mpi_limp_t *rp,
+		     mpi_limp_t *a1,
+		     mpi_limp_t *a0,
+		     mpi_limp_t *d   )
+{
+  mp_limb_t q, r;
+  mp_limb_t c0, c1, b1;
+
+  if ((mpi_limb_signed_t) d >= 0)
+    {
+      if (a1 < d - a1 - (a0 >> (BITS_PER_MP_LIMB - 1)))
+	{
+	  /* dividend, divisor, and quotient are nonnegative */
+	  sdiv_qrnnd (q, r, a1, a0, d);
+	}
+      else
+	{
+	  /* Compute c1*2^32 + c0 = a1*2^32 + a0 - 2^31*d */
+	  sub_ddmmss (c1, c0, a1, a0, d >> 1, d << (BITS_PER_MP_LIMB - 1));
+	  /* Divide (c1*2^32 + c0) by d */
+	  sdiv_qrnnd (q, r, c1, c0, d);
+	  /* Add 2^31 to quotient */
+	  q += (mp_limb_t) 1 << (BITS_PER_MP_LIMB - 1);
+	}
+    }
+  else
+    {
+      b1 = d >> 1;			/* d/2, between 2^30 and 2^31 - 1 */
+      c1 = a1 >> 1;			/* A/2 */
+      c0 = (a1 << (BITS_PER_MP_LIMB - 1)) + (a0 >> 1);
+
+      if (a1 < b1)			/* A < 2^32*b1, so A/2 < 2^31*b1 */
+	{
+	  sdiv_qrnnd (q, r, c1, c0, b1); /* (A/2) / (d/2) */
+
+	  r = 2*r + (a0 & 1);		/* Remainder from A/(2*b1) */
+	  if ((d & 1) != 0)
+	    {
+	      if (r >= q)
+		r = r - q;
+	      else if (q - r <= d)
+		{
+		  r = r - q + d;
+		  q--;
+		}
+	      else
+		{
+		  r = r - q + 2*d;
+		  q -= 2;
+		}
+	    }
+	}
+      else if (c1 < b1) 		/* So 2^31 <= (A/2)/b1 < 2^32 */
+	{
+	  c1 = (b1 - 1) - c1;
+	  c0 = ~c0;			/* logical NOT */
+
+	  sdiv_qrnnd (q, r, c1, c0, b1); /* (A/2) / (d/2) */
+
+	  q = ~q;			/* (A/2)/b1 */
+	  r = (b1 - 1) - r;
+
+	  r = 2*r + (a0 & 1);		/* A/(2*b1) */
+
+	  if ((d & 1) != 0)
+	    {
+	      if (r >= q)
+		r = r - q;
+	      else if (q - r <= d)
+		{
+		  r = r - q + d;
+		  q--;
+		}
+	      else
+		{
+		  r = r - q + 2*d;
+		  q -= 2;
+		}
+	    }
+	}
+      else				/* Implies c1 = b1 */
+	{				/* Hence a1 = d - 1 = 2*b1 - 1 */
+	  if (a0 >= -d)
+	    {
+	      q = -1;
+	      r = a0 + d;
+	    }
+	  else
+	    {
+	      q = -2;
+	      r = a0 + 2*d;
+	    }
+	}
+    }
+
+  *rp = r;
+  return q;
+}
+
+#endif
+