1 files changed, 39 insertions, 0 deletions
diff --git a/lib/fixunsdfsi.c b/lib/fixunsdfsi.c
new file mode 100644
index 000000000..383a35efe
--- /dev/null
+++ b/lib/fixunsdfsi.c
@@ -0,0 +1,39 @@
+//===-- fixunsdfsi.c - Implement __fixunsdfsi -----------------------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+// This file implements __fixunsdfsi for the compiler_rt library.
+//
+//===----------------------------------------------------------------------===//
+
+#include "int_lib.h"
+
+// Returns: convert a to a unsigned int, rounding toward zero.
+//          Negative values all become zero.
+
+// Assumption: double is a IEEE 64 bit floating point type 
+//             su_int is a 32 bit integral type
+//             value in double is representable in su_int or is negative 
+//                 (no range checking performed)
+
+// seee eeee eeee mmmm mmmm mmmm mmmm mmmm | mmmm mmmm mmmm mmmm mmmm mmmm mmmm mmmm
+
+su_int
+__fixunsdfsi(double a)
+{
+    double_bits fb;
+    fb.f = a;
+    int e = ((fb.u.high & 0x7FF00000) >> 20) - 1023;
+    if (e < 0 || (fb.u.high & 0x80000000))
+        return 0;
+    return (
+                0x80000000u                      |
+                ((fb.u.high & 0x000FFFFF) << 11) |
+                (fb.u.low >> 21)
+           ) >> (31 - e);
+}