1 files changed, 29 insertions, 0 deletions
diff --git a/compiler-rt/lib/builtins/ctzti2.c b/compiler-rt/lib/builtins/ctzti2.c
new file mode 100644
index 000000000000..2a1312c8437d
--- /dev/null
+++ b/compiler-rt/lib/builtins/ctzti2.c
@@ -0,0 +1,29 @@
+//===-- ctzti2.c - Implement __ctzti2 -------------------------------------===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+//
+// This file implements __ctzti2 for the compiler_rt library.
+//
+//===----------------------------------------------------------------------===//
+
+#include "int_lib.h"
+
+#ifdef CRT_HAS_128BIT
+
+// Returns: the number of trailing 0-bits
+
+// Precondition: a != 0
+
+COMPILER_RT_ABI 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 // CRT_HAS_128BIT