Move original compiler-rt functions (libgcc replacement) to lib/builtins directory

llvm-svn: 201393

1 files changed, 44 insertions, 0 deletions

diff --git a/compiler-rt/lib/builtins/fixunsxfsi.c b/compiler-rt/lib/builtins/fixunsxfsi.c
new file mode 100644
index 00000000000..b9da86c4f8e
--- /dev/null
+++ b/compiler-rt/lib/builtins/fixunsxfsi.c
@@ -0,0 +1,44 @@
+/* ===-- fixunsxfsi.c - Implement __fixunsxfsi -----------------------------===
+ *
+ *                     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 __fixunsxfsi for the compiler_rt library.
+ *
+ * ===----------------------------------------------------------------------===
+ */
+
+#if !_ARCH_PPC
+
+#include "int_lib.h"
+
+/* Returns: convert a to a unsigned int, rounding toward zero.
+ *          Negative values all become zero.
+ */
+
+/* Assumption: long double is an intel 80 bit floating point type padded with 6 bytes
+ *             su_int is a 32 bit integral type
+ *             value in long double is representable in su_int or is negative 
+ *                 (no range checking performed)
+ */
+
+/* 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
+ */
+
+su_int
+__fixunsxfsi(long double a)
+{
+    long_double_bits fb;
+    fb.f = a;
+    int e = (fb.u.high.s.low & 0x00007FFF) - 16383;
+    if (e < 0 || (fb.u.high.s.low & 0x00008000))
+        return 0;
+    return fb.u.low.s.high >> (31 - e);
+}
+
+#endif /* !_ARCH_PPC */