--- /dev/null
+/* mpn_subcnd_n -- Compute R = U - V if CND != 0 or R = U if CND == 0.
+
+ THIS IS AN INTERNAL FUNCTION WITH A MUTABLE INTERFACE. IT IS ONLY
+ SAFE TO REACH THIS FUNCTION THROUGH DOCUMENTED INTERFACES.
+
+Copyright 1992, 1993, 1994, 1996, 2000, 2002, 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"
+
+
+#if GMP_NAIL_BITS == 0
+
+mp_limb_t
+mpn_subcnd_n (mp_ptr rp, mp_srcptr up, mp_srcptr vp, mp_size_t n, mp_limb_t cnd)
+{
+ mp_limb_t ul, vl, sl, rl, cy, cy1, cy2, mask;
+
+ ASSERT (n >= 1);
+ ASSERT (MPN_SAME_OR_SEPARATE_P (rp, up, n));
+ ASSERT (MPN_SAME_OR_SEPARATE_P (rp, vp, n));
+
+ mask = -(mp_limb_t) (cnd != 0);
+ cy = 0;
+ do
+ {
+ ul = *up++;
+ vl = *vp++ & mask;
+ sl = ul - vl;
+ cy1 = sl > ul;
+ rl = sl - cy;
+ cy2 = rl > sl;
+ cy = cy1 | cy2;
+ *rp++ = rl;
+ }
+ while (--n != 0);
+
+ return cy;
+}
+
+#endif
+
+#if GMP_NAIL_BITS >= 1
+
+mp_limb_t
+mpn_subcnd_n (mp_ptr rp, mp_srcptr up, mp_srcptr vp, mp_size_t n, mp_limb_t cnd)
+{
+ mp_limb_t ul, vl, rl, cy, mask;
+
+ ASSERT (n >= 1);
+ ASSERT (MPN_SAME_OR_SEPARATE_P (rp, up, n));
+ ASSERT (MPN_SAME_OR_SEPARATE_P (rp, vp, n));
+
+ mask = -(mp_limb_t) (cnd != 0);
+ cy = 0;
+ do
+ {
+ ul = *up++;
+ vl = *vp++ & mask;
+ rl = ul - vl - cy;
+ cy = rl >> (GMP_LIMB_BITS - 1);
+ *rp++ = rl & GMP_NUMB_MASK;
+ }
+ while (--n != 0);
+
+ return cy;
+}
+
+#endif