1 files changed, 34 insertions, 0 deletions
diff --git a/lib/builtins/powidf2.c b/lib/builtins/powidf2.c
new file mode 100644
index 000000000000..ac13b172b043
--- /dev/null
+++ b/lib/builtins/powidf2.c
@@ -0,0 +1,34 @@
+/* ===-- powidf2.cpp - Implement __powidf2 ---------------------------------===
+ *
+ *                     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 __powidf2 for the compiler_rt library.
+ *
+ * ===----------------------------------------------------------------------===
+ */
+
+#include "int_lib.h"
+
+/* Returns: a ^ b */
+
+COMPILER_RT_ABI double
+__powidf2(double a, si_int b)
+{
+    const int recip = b < 0;
+    double r = 1;
+    while (1)
+    {
+        if (b & 1)
+            r *= a;
+        b /= 2;
+        if (b == 0)
+            break;
+        a *= a;
+    }
+    return recip ? 1/r : r;
+}