diff --git a/lib/negvdi2.c b/lib/negvdi2.c
new file mode 100644
index 0000000..eb9f6e9
--- /dev/null
+++ b/lib/negvdi2.c
@@ -0,0 +1,28 @@
+//===-- negvdi2.c - Implement __negvdi2 -----------------------------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+// This file implements __negvdi2 for the compiler_rt library.
+//
+//===----------------------------------------------------------------------===//
+
+#include "int_lib.h"
+#include <stdlib.h>
+
+// Returns: -a
+
+// Effects: aborts if -a overflows
+
+di_int
+__negvdi2(di_int a)
+{
+    const di_int MIN = (di_int)1 << ((int)(sizeof(di_int) * CHAR_BIT)-1);
+    if (a == MIN)
+        abort();
+    return -a;
+}