diff --git a/lib/compiler-rt/builtins/divmoddi4.c b/lib/compiler-rt/builtins/divmoddi4.c
index 0d4df67..e7cbbb1 100644
--- a/lib/compiler-rt/builtins/divmoddi4.c
+++ b/lib/compiler-rt/builtins/divmoddi4.c
@@ -1,25 +1,28 @@
-/*===-- divmoddi4.c - Implement __divmoddi4 --------------------------------===
- *
- *                    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 __divmoddi4 for the compiler_rt library.
- *
- * ===----------------------------------------------------------------------===
- */
+//===-- divmoddi4.c - Implement __divmoddi4 -------------------------------===//
+//
+// 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 __divmoddi4 for the compiler_rt library.
+//
+//===----------------------------------------------------------------------===//
 
 #include "int_lib.h"
 
-/* Returns: a / b, *rem = a % b  */
+// Returns: a / b, *rem = a % b
 
-COMPILER_RT_ABI di_int
-__divmoddi4(di_int a, di_int b, di_int* rem)
-{
-  di_int d = __divdi3(a,b);
-  *rem = a - (d*b);
-  return d;
+COMPILER_RT_ABI di_int __divmoddi4(di_int a, di_int b, di_int *rem) {
+  const int bits_in_dword_m1 = (int)(sizeof(di_int) * CHAR_BIT) - 1;
+  di_int s_a = a >> bits_in_dword_m1;                   // s_a = a < 0 ? -1 : 0
+  di_int s_b = b >> bits_in_dword_m1;                   // s_b = b < 0 ? -1 : 0
+  a = (a ^ s_a) - s_a;                                  // negate if s_a == -1
+  b = (b ^ s_b) - s_b;                                  // negate if s_b == -1
+  s_b ^= s_a;                                           // sign of quotient
+  du_int r;
+  di_int q = (__udivmoddi4(a, b, &r) ^ s_b) - s_b;      // negate if s_b == -1
+  *rem = (r ^ s_a) - s_a;                               // negate if s_a == -1
+  return q;
 }