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

git-svn-id: https://llvm.org/svn/llvm-project/compiler-rt/trunk@201393 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 47 insertions, 0 deletions

diff --git a/lib/builtins/fixxfti.c b/lib/builtins/fixxfti.c
new file mode 100644
index 000000000..973dc31bf
--- /dev/null
+++ b/lib/builtins/fixxfti.c
@@ -0,0 +1,47 @@
+/* ===-- fixxfti.c - Implement __fixxfti -----------------------------------===
+ *
+ *      	       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 __fixxfti for the compiler_rt library.
+ *
+ * ===----------------------------------------------------------------------===
+ */
+
+#include "int_lib.h"
+
+#if __x86_64
+
+/* Returns: convert a to a signed long long, rounding toward 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 ti_int (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
+ */
+
+ti_int
+__fixxfti(long double a)
+{
+    long_double_bits fb;
+    fb.f = a;
+    int e = (fb.u.high.s.low & 0x00007FFF) - 16383;
+    if (e < 0)
+        return 0;
+    ti_int s = -(si_int)((fb.u.high.s.low & 0x00008000) >> 15);
+    ti_int r = fb.u.low.all;
+    if (e > 63)
+        r <<= (e - 63);
+    else
+        r >>= (63 - e);
+    return (r ^ s) - s;
+}
+
+#endif /* __x86_64 */