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

llvm-svn: 201393

1 files changed, 42 insertions, 0 deletions

diff --git a/compiler-rt/lib/builtins/floatundixf.c b/compiler-rt/lib/builtins/floatundixf.c
new file mode 100644
index 00000000000..64f7662d952
--- /dev/null
+++ b/compiler-rt/lib/builtins/floatundixf.c
@@ -0,0 +1,42 @@
+/* ===-- floatundixf.c - Implement __floatundixf ---------------------------===
+ *
+ *                     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 __floatundixf 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
+ *             du_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
+ */
+long double
+__floatundixf(du_int a)
+{
+    if (a == 0)
+        return 0.0;
+    const unsigned N = sizeof(du_int) * CHAR_BIT;
+    int clz = __builtin_clzll(a);
+    int e = (N - 1) - clz ;    /* exponent */
+    long_double_bits fb;
+    fb.u.high.s.low = (e + 16383);              /* exponent */
+    fb.u.low.all = a << clz;                   /* mantissa */
+    return fb.f;
+}
+
+#endif /* _ARCH_PPC */