1 files changed, 33 insertions, 0 deletions
diff --git a/contrib/compiler-rt/lib/ctzti2.c b/contrib/compiler-rt/lib/ctzti2.c
new file mode 100644
index 0000000..1c9508f
--- /dev/null
+++ b/contrib/compiler-rt/lib/ctzti2.c
@@ -0,0 +1,33 @@
+/* ===-- ctzti2.c - Implement __ctzti2 -------------------------------------===
+ *
+ *                     The LLVM Compiler Infrastructure
+ *
+ * This file is dual licensed under the MIT and the University of Illinois Open
+ * Source Licenses. See LICENSE.TXT for details.
+ *
+ * ===----------------------------------------------------------------------===
+ *
+ * This file implements __ctzti2 for the compiler_rt library.
+ *
+ * ===----------------------------------------------------------------------===
+ */
+
+#if __x86_64
+
+#include "int_lib.h"
+
+/* Returns: the number of trailing 0-bits */
+
+/* Precondition: a != 0 */
+
+si_int
+__ctzti2(ti_int a)
+{
+    twords x;
+    x.all = a;
+    const di_int f = -(x.s.low == 0);
+    return __builtin_ctzll((x.s.high & f) | (x.s.low & ~f)) +
+              ((si_int)f & ((si_int)(sizeof(di_int) * CHAR_BIT)));
+}
+
+#endif