Add libgmp 6.2.0 to third_party
Don't build it yet. That will come in the next review.
Change-Id: Idf3266558165e5ab45f4a41c98cc8c838c8244d5
diff --git a/third_party/gmp/mpn/generic/scan0.c b/third_party/gmp/mpn/generic/scan0.c
new file mode 100644
index 0000000..d71832e
--- /dev/null
+++ b/third_party/gmp/mpn/generic/scan0.c
@@ -0,0 +1,59 @@
+/* mpn_scan0 -- Scan from a given bit position for the next clear bit.
+
+Copyright 1994, 1996, 2001, 2002, 2004 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"
+#include "longlong.h"
+
+/* Argument constraints:
+ 1. U must sooner or later have a limb with a clear bit.
+ */
+
+mp_bitcnt_t
+mpn_scan0 (mp_srcptr up, mp_bitcnt_t starting_bit)
+{
+ mp_size_t starting_word;
+ mp_limb_t alimb;
+ int cnt;
+ mp_srcptr p;
+
+ /* Start at the word implied by STARTING_BIT. */
+ starting_word = starting_bit / GMP_NUMB_BITS;
+ p = up + starting_word;
+ alimb = *p++ ^ GMP_NUMB_MASK;
+
+ /* Mask off any bits before STARTING_BIT in the first limb. */
+ alimb &= - (mp_limb_t) 1 << (starting_bit % GMP_NUMB_BITS);
+
+ while (alimb == 0)
+ alimb = *p++ ^ GMP_NUMB_MASK;
+
+ count_trailing_zeros (cnt, alimb);
+ return (p - up - 1) * GMP_NUMB_BITS + cnt;
+}