zte's code,first commit

Change-Id: I9a04da59e459a9bc0d67f101f700d9d7dc8d681b
diff --git a/ap/build/uClibc/libm/s_copysign.c b/ap/build/uClibc/libm/s_copysign.c
new file mode 100644
index 0000000..33e1531
--- /dev/null
+++ b/ap/build/uClibc/libm/s_copysign.c
@@ -0,0 +1,29 @@
+/*
+ * ====================================================
+ * Copyright (C) 1993 by Sun Microsystems, Inc. All rights reserved.
+ *
+ * Developed at SunPro, a Sun Microsystems, Inc. business.
+ * Permission to use, copy, modify, and distribute this
+ * software is freely granted, provided that this notice
+ * is preserved.
+ * ====================================================
+ */
+
+/*
+ * copysign(double x, double y)
+ * copysign(x,y) returns a value with the magnitude of x and
+ * with the sign bit of y.
+ */
+
+#include "math.h"
+#include "math_private.h"
+
+double copysign(double x, double y)
+{
+	u_int32_t hx,hy;
+	GET_HIGH_WORD(hx,x);
+	GET_HIGH_WORD(hy,y);
+	SET_HIGH_WORD(x,(hx&0x7fffffff)|(hy&0x80000000));
+        return x;
+}
+libm_hidden_def(copysign)