1 files changed, 27 insertions, 0 deletions
diff --git a/cpukit/compiler-rt/lib/builtins/ffsdi2.c b/cpukit/compiler-rt/lib/builtins/ffsdi2.c
new file mode 100644
index 0000000000..beae553043
--- /dev/null
+++ b/cpukit/compiler-rt/lib/builtins/ffsdi2.c
@@ -0,0 +1,27 @@
+//===-- ffsdi2.c - Implement __ffsdi2 -------------------------------------===//
+//
+// 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 __ffsdi2 for the compiler_rt library.
+//
+//===----------------------------------------------------------------------===//
+
+#include "int_lib.h"
+
+// Returns: the index of the least significant 1-bit in a, or
+// the value zero if a is zero. The least significant bit is index one.
+
+COMPILER_RT_ABI int __ffsdi2(di_int a) {
+  dwords x;
+  x.all = a;
+  if (x.s.low == 0) {
+    if (x.s.high == 0)
+      return 0;
+    return ctzsi(x.s.high) + (1 + sizeof(si_int) * CHAR_BIT);
+  }
+  return ctzsi(x.s.low) + 1;
+}