auto import from //depot/cupcake/@135843
diff --git a/libm/src/s_asinh.c b/libm/src/s_asinh.c
new file mode 100644
index 0000000..079007f
--- /dev/null
+++ b/libm/src/s_asinh.c
@@ -0,0 +1,57 @@
+/* @(#)s_asinh.c 5.1 93/09/24 */
+/*
+ * ====================================================
+ * 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.
+ * ====================================================
+ */
+
+#ifndef lint
+static char rcsid[] = "$FreeBSD: src/lib/msun/src/s_asinh.c,v 1.8 2002/05/28 18:15:04 alfred Exp $";
+#endif
+
+/* asinh(x)
+ * Method :
+ * Based on
+ * asinh(x) = sign(x) * log [ |x| + sqrt(x*x+1) ]
+ * we have
+ * asinh(x) := x if 1+x*x=1,
+ * := sign(x)*(log(x)+ln2)) for large |x|, else
+ * := sign(x)*log(2|x|+1/(|x|+sqrt(x*x+1))) if|x|>2, else
+ * := sign(x)*log1p(|x| + x^2/(1 + sqrt(1+x^2)))
+ */
+
+#include "math.h"
+#include "math_private.h"
+
+static const double
+one = 1.00000000000000000000e+00, /* 0x3FF00000, 0x00000000 */
+ln2 = 6.93147180559945286227e-01, /* 0x3FE62E42, 0xFEFA39EF */
+huge= 1.00000000000000000000e+300;
+
+double
+asinh(double x)
+{
+ double t,w;
+ int32_t hx,ix;
+ GET_HIGH_WORD(hx,x);
+ ix = hx&0x7fffffff;
+ if(ix>=0x7ff00000) return x+x; /* x is inf or NaN */
+ if(ix< 0x3e300000) { /* |x|<2**-28 */
+ if(huge+x>one) return x; /* return x inexact except 0 */
+ }
+ if(ix>0x41b00000) { /* |x| > 2**28 */
+ w = __ieee754_log(fabs(x))+ln2;
+ } else if (ix>0x40000000) { /* 2**28 > |x| > 2.0 */
+ t = fabs(x);
+ w = __ieee754_log(2.0*t+one/(__ieee754_sqrt(x*x+one)+t));
+ } else { /* 2.0 > |x| > 2**-28 */
+ t = x*x;
+ w =log1p(fabs(x)+t/(one+__ieee754_sqrt(one+t)));
+ }
+ if(hx>0) return w; else return -w;
+}