1 files changed, 36 insertions, 0 deletions
diff --git a/lib/builtins/subvsi3.c b/lib/builtins/subvsi3.c
new file mode 100644
index 0000000000000..e6c0fb688c973
--- /dev/null
+++ b/lib/builtins/subvsi3.c
@@ -0,0 +1,36 @@
+/* ===-- subvsi3.c - Implement __subvsi3 -----------------------------------===
+ *
+ *                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 __subvsi3 for the compiler_rt library.
+ *
+ * ===----------------------------------------------------------------------===
+ */
+
+#include "int_lib.h"
+
+/* Returns: a - b */
+
+/* Effects: aborts if a - b overflows */
+
+COMPILER_RT_ABI si_int
+__subvsi3(si_int a, si_int b)
+{
+    si_int s = (su_int) a - (su_int) b;
+    if (b >= 0)
+    {
+        if (s > a)
+            compilerrt_abort();
+    }
+    else
+    {
+        if (s <= a)
+            compilerrt_abort();
+    }
+    return s;
+}