1 files changed, 30 insertions, 0 deletions
diff --git a/lib/builtins/moddi3.c b/lib/builtins/moddi3.c
new file mode 100644
index 000000000000..a04279e3875f
--- /dev/null
+++ b/lib/builtins/moddi3.c
@@ -0,0 +1,30 @@
+/*===-- moddi3.c - Implement __moddi3 -------------------------------------===
+ *
+ *                    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 __moddi3 for the compiler_rt library.
+ *
+ * ===----------------------------------------------------------------------===
+ */
+
+#include "int_lib.h"
+
+/* Returns: a % b */
+
+COMPILER_RT_ABI di_int
+__moddi3(di_int a, di_int b)
+{
+    const int bits_in_dword_m1 = (int)(sizeof(di_int) * CHAR_BIT) - 1;
+    di_int s = b >> bits_in_dword_m1;  /* s = b < 0 ? -1 : 0 */
+    b = (b ^ s) - s;                   /* negate if s == -1 */
+    s = a >> bits_in_dword_m1;         /* s = a < 0 ? -1 : 0 */
+    a = (a ^ s) - s;                   /* negate if s == -1 */
+    du_int r;
+    __udivmoddi4(a, b, &r);
+    return ((di_int)r ^ s) - s;                /* negate if s == -1 */
+}