1 files changed, 69 insertions, 0 deletions
diff --git a/gmp-6.3.0/mpn/generic/cnd_add_n.c b/gmp-6.3.0/mpn/generic/cnd_add_n.c
new file mode 100644
index 0000000..e6b1373
--- /dev/null
+++ b/gmp-6.3.0/mpn/generic/cnd_add_n.c
@@ -0,0 +1,69 @@
+/* mpn_cnd_add_n -- Compute R = U + V if CND != 0 or R = U if CND == 0.
+   Both cases should take the same time and perform the exact same memory
+   accesses, since this function is intended to be used where side-channel
+   attack resilience is relevant.
+
+Copyright 1992-1994, 1996, 2000, 2002, 2008, 2009, 2011, 2013 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 either:
+
+  * 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.
+
+or
+
+  * the GNU General Public License as published by the Free Software
+    Foundation; either version 2 of the License, or (at your option) any
+    later version.
+
+or both in parallel, as here.
+
+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 copies of the GNU General Public License and the
+GNU Lesser General Public License along with the GNU MP Library.  If not,
+see https://www.gnu.org/licenses/.  */
+
+#include "gmp-impl.h"
+
+mp_limb_t
+mpn_cnd_add_n (mp_limb_t cnd, mp_ptr rp, mp_srcptr up, mp_srcptr vp, mp_size_t n)
+{
+  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;
+#if GMP_NAIL_BITS == 0
+      sl = ul + vl;
+      cy1 = sl < ul;
+      rl = sl + cy;
+      cy2 = rl < sl;
+      cy = cy1 | cy2;
+      *rp++ = rl;
+#else
+      rl = ul + vl;
+      rl += cy;
+      cy = rl >> GMP_NUMB_BITS;
+      *rp++ = rl & GMP_NUMB_MASK;
+#endif
+    }
+  while (--n != 0);
+
+  return cy;
+}