first commit of the new libm!

[musl] / src / math / scalb.c

diff --git a/src/math/scalb.c b/src/math/scalb.c
new file mode 100644 (file)
index 0000000..7706e9c
--- /dev/null
+++ b/src/math/scalb.c
@@ -0,0 +1,34 @@
+/* origin: FreeBSD /usr/src/lib/msun/src/e_scalb.c */
+/*
+ * ====================================================
+ * Copyright (C) 1993 by Sun Microsystems, Inc. All rights reserved.
+ *
+ * Developed at SunSoft, a Sun Microsystems, Inc. business.
+ * Permission to use, copy, modify, and distribute this
+ * software is freely granted, provided that this notice
+ * is preserved.
+ * ====================================================
+ */
+/*
+ * scalb(x, fn) is provide for
+ * passing various standard test suite. One
+ * should use scalbn() instead.
+ */
+
+#include "libm.h"
+
+double scalb(double x, double fn)
+{
+       if (isnan(x) || isnan(fn))
+               return x*fn;
+       if (!isfinite(fn)) {
+               if (fn > 0.0)
+                       return x*fn;
+               else
+                       return x/(-fn);
+       }
+       if (rint(fn) != fn) return (fn-fn)/(fn-fn);
+       if ( fn > 65000.0) return scalbn(x, 65000);
+       if (-fn > 65000.0) return scalbn(x,-65000);
+       return scalbn(x,(int)fn);
+}