newlib: update

git-svn-id: svn://kolibrios.org@1906 a494cfbc-eb01-0410-851d-a64ba20cac60

programs/develop/libraries/newlib/math/asinh.c

@@ -0,0 +1,28 @@
+#include <math.h>
+#include <errno.h>
+#include "fastmath.h"
+
+ /* asinh(x) = copysign(log(fabs(x) + sqrt(x * x + 1.0)), x) */
+double asinh(double x)
+{
+  double z;
+  if (!isfinite (x))
+    return x;
+  z = fabs (x);
+
+  /* Avoid setting FPU underflow exception flag in x * x. */
+#if 0
+  if ( z < 0x1p-32)
+    return x;
+#endif
+
+  /* Use log1p to avoid cancellation with small x. Put
+     x * x in denom, so overflow is harmless. 
+     asinh(x) = log1p (x + sqrt (x * x + 1.0) - 1.0)
+              = log1p (x + x * x / (sqrt (x * x + 1.0) + 1.0))  */
+
+  z = __fast_log1p (z + z * z / (__fast_sqrt (z * z + 1.0) + 1.0));
+
+  return ( x > 0.0 ? z : -z);
+}
+