1 files changed, 46 insertions, 0 deletions
diff --git a/lib/builtins/floatdixf.c b/lib/builtins/floatdixf.c
new file mode 100644
index 000000000000..d39e81d7ca75
--- /dev/null
+++ b/lib/builtins/floatdixf.c
@@ -0,0 +1,46 @@
+/* ===-- floatdixf.c - Implement __floatdixf -------------------------------===
+ *
+ *                     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 __floatdixf for the compiler_rt library.
+ *
+ * ===----------------------------------------------------------------------===
+ */ 
+
+#if !_ARCH_PPC
+
+#include "int_lib.h"
+
+/* Returns: convert a to a long double, rounding toward even. */
+
+/* Assumption: long double is a IEEE 80 bit floating point type padded to 128 bits
+ *             di_int is a 64 bit integral type
+ */
+
+/* gggg gggg gggg gggg gggg gggg gggg gggg | gggg gggg gggg gggg seee eeee eeee eeee |
+ * 1mmm mmmm mmmm mmmm mmmm mmmm mmmm mmmm | mmmm mmmm mmmm mmmm mmmm mmmm mmmm mmmm
+ */
+
+COMPILER_RT_ABI long double
+__floatdixf(di_int a)
+{
+    if (a == 0)
+        return 0.0;
+    const unsigned N = sizeof(di_int) * CHAR_BIT;
+    const di_int s = a >> (N-1);
+    a = (a ^ s) - s;
+    int clz = __builtin_clzll(a);
+    int e = (N - 1) - clz ;    /* exponent */
+    long_double_bits fb;
+    fb.u.high.s.low = ((su_int)s & 0x00008000) |  /* sign */
+		      (e + 16383);                /* exponent */
+    fb.u.low.all = a << clz;                    /* mantissa */
+    return fb.f;
+}
+
+#endif /* !_ARCH_PPC */