Split into add_n.c and sub_n.c.

2 files changed, 63 insertions, 18 deletions

diff --git a/mpn/generic/aors_n.c b/mpn/generic/add_n.c
index f361ae465..8209d4e43 100644
--- a/mpn/generic/aors_n.c
+++ b/mpn/generic/add_n.c
@@ -23,23 +23,8 @@ MA 02111-1307, USA. */
 #include "gmp-impl.h"
 
 
-#ifdef OPERATION_add_n
-#define FUNCTION   mpn_add_n
-#define VARIATION  y = x + y; cy += (y < x);
-#endif
-
-#ifdef OPERATION_sub_n
-#define FUNCTION   mpn_sub_n
-#define VARIATION  y = x - y; cy += (y > x);
-#endif
-
-#ifndef FUNCTION
-Error, error, need OPERATION_add_n or OPERATION_sub_n
-#endif
-
-
 mp_limb_t
-FUNCTION (mp_ptr res_ptr, mp_srcptr s1_ptr, mp_srcptr s2_ptr, mp_size_t size)
+mpn_add_n (mp_ptr res_ptr, mp_srcptr s1_ptr, mp_srcptr s2_ptr, mp_size_t size)
 {
   register mp_limb_t x, y, cy;
   register mp_size_t j;
@@ -63,8 +48,9 @@ FUNCTION (mp_ptr res_ptr, mp_srcptr s1_ptr, mp_srcptr s2_ptr, mp_size_t size)
       y = s2_ptr[j];
       x = s1_ptr[j];
       y += cy;	     	/* previous carry/borrow into second operand */
-      cy = (y < cy);	/* new carry from that                       */
-      VARIATION;        /* this add or sub, and its carry            */
+      cy = y < cy;	/* new carry from that                       */
+      y = x + y;
+      cy += y < x;
       res_ptr[j] = y;
     }
   while (++j != 0);
diff --git a/mpn/generic/sub_n.c b/mpn/generic/sub_n.c
new file mode 100644
index 000000000..e7be6a47a
--- /dev/null
+++ b/mpn/generic/sub_n.c
@@ -0,0 +1,59 @@
+/* mpn_add_n, mpn_sub_n -- add or subtract equal length limb vectors.
+
+Copyright 1992, 1993, 1994, 1996, 2000 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 2.1 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; 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"
+
+
+mp_limb_t
+mpn_sub_n (mp_ptr res_ptr, mp_srcptr s1_ptr, mp_srcptr s2_ptr, mp_size_t size)
+{
+  register mp_limb_t x, y, cy;
+  register mp_size_t j;
+
+  ASSERT (size >= 1);
+  ASSERT (MPN_SAME_OR_SEPARATE_P (res_ptr, s1_ptr, size));
+  ASSERT (MPN_SAME_OR_SEPARATE_P (res_ptr, s2_ptr, size));
+
+  /* The loop counter and index J goes from -SIZE to -1.  This way
+     the loop becomes faster.  */
+  j = -size;
+
+  /* Offset the base pointers to compensate for the negative indices.  */
+  s1_ptr -= j;
+  s2_ptr -= j;
+  res_ptr -= j;
+
+  cy = 0;
+  do
+    {
+      y = s2_ptr[j];
+      x = s1_ptr[j];
+      y += cy;	     	/* previous carry/borrow into second operand */
+      cy = y < cy;	/* new carry from that                       */
+      y = x - y;
+      cy += y > x;
+      res_ptr[j] = y;
+    }
+  while (++j != 0);
+
+  return cy;
+}