--- /dev/null	Sat May 10 12:08:54 2014
+++ new/usr/src/lib/libm/common/C/log1p.c	Sat May 10 12:08:54 2014
@@ -0,0 +1,204 @@
+/*
+ * CDDL HEADER START
+ *
+ * The contents of this file are subject to the terms of the
+ * Common Development and Distribution License (the "License").
+ * You may not use this file except in compliance with the License.
+ *
+ * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
+ * or http://www.opensolaris.org/os/licensing.
+ * See the License for the specific language governing permissions
+ * and limitations under the License.
+ *
+ * When distributing Covered Code, include this CDDL HEADER in each
+ * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
+ * If applicable, add the following below this CDDL HEADER, with the
+ * fields enclosed by brackets "[]" replaced with your own identifying
+ * information: Portions Copyright [yyyy] [name of copyright owner]
+ *
+ * CDDL HEADER END
+ */
+/*
+ * Copyright 2011 Nexenta Systems, Inc.  All rights reserved.
+ */
+/*
+ * Copyright 2005 Sun Microsystems, Inc.  All rights reserved.
+ * Use is subject to license terms.
+ */
+
+#pragma weak log1p = __log1p
+
+/* INDENT OFF */
+/*
+ * Method :
+ *   1. Argument Reduction: find k and f such that
+ *			1+x = 2^k * (1+f),
+ *	   where  sqrt(2)/2 < 1+f < sqrt(2) .
+ *
+ *      Note. If k=0, then f=x is exact. However, if k!=0, then f
+ *	may not be representable exactly. In that case, a correction
+ *	term is need. Let u=1+x rounded. Let c = (1+x)-u, then
+ *	log(1+x) - log(u) ~ c/u. Thus, we proceed to compute log(u),
+ *	and add back the correction term c/u.
+ *	(Note: when x > 2**53, one can simply return log(x))
+ *
+ *   2. Approximation of log1p(f).
+ *	Let s = f/(2+f) ; based on log(1+f) = log(1+s) - log(1-s)
+ *		 = 2s + 2/3 s**3 + 2/5 s**5 + .....,
+ *		 = 2s + s*R
+ *      We use a special Reme algorithm on [0,0.1716] to generate
+ * 	a polynomial of degree 14 to approximate R The maximum error
+ *	of this polynomial approximation is bounded by 2**-58.45. In
+ *	other words,
+ *		        2      4      6      8      10      12      14
+ *	    R(z) ~ Lp1*s +Lp2*s +Lp3*s +Lp4*s +Lp5*s  +Lp6*s  +Lp7*s
+ *  	(the values of Lp1 to Lp7 are listed in the program)
+ *	and
+ *	    |      2          14          |     -58.45
+ *	    | Lp1*s +...+Lp7*s    -  R(z) | <= 2
+ *	    |                             |
+ *	Note that 2s = f - s*f = f - hfsq + s*hfsq, where hfsq = f*f/2.
+ *	In order to guarantee error in log below 1ulp, we compute log
+ *	by
+ *		log1p(f) = f - (hfsq - s*(hfsq+R)).
+ *
+ *	3. Finally, log1p(x) = k*ln2 + log1p(f).
+ *			     = k*ln2_hi+(f-(hfsq-(s*(hfsq+R)+k*ln2_lo)))
+ *	   Here ln2 is splitted into two floating point number:
+ *			ln2_hi + ln2_lo,
+ *	   where n*ln2_hi is always exact for |n| < 2000.
+ *
+ * Special cases:
+ *	log1p(x) is NaN with signal if x < -1 (including -INF) ;
+ *	log1p(+INF) is +INF; log1p(-1) is -INF with signal;
+ *	log1p(NaN) is that NaN with no signal.
+ *
+ * Accuracy:
+ *	according to an error analysis, the error is always less than
+ *	1 ulp (unit in the last place).
+ *
+ * Constants:
+ * The hexadecimal values are the intended ones for the following
+ * constants. The decimal values may be used, provided that the
+ * compiler will convert from decimal to binary accurately enough
+ * to produce the hexadecimal values shown.
+ *
+ * Note: Assuming log() return accurate answer, the following
+ *	 algorithm can be used to compute log1p(x) to within a few ULP:
+ *
+ *		u = 1+x;
+ *		if(u==1.0) return x ; else
+ *			   return log(u)*(x/(u-1.0));
+ *
+ *	 See HP-15C Advanced Functions Handbook, p.193.
+ */
+/* INDENT ON */
+
+#include "libm.h"
+
+static const double xxx[] = {
+/* ln2_hi */	6.93147180369123816490e-01,	/* 3fe62e42 fee00000 */
+/* ln2_lo */	1.90821492927058770002e-10,	/* 3dea39ef 35793c76 */
+/* two54 */	1.80143985094819840000e+16,	/* 43500000 00000000 */
+/* Lp1 */	6.666666666666735130e-01,	/* 3FE55555 55555593 */
+/* Lp2 */	3.999999999940941908e-01,	/* 3FD99999 9997FA04 */
+/* Lp3 */	2.857142874366239149e-01,	/* 3FD24924 94229359 */
+/* Lp4 */	2.222219843214978396e-01,	/* 3FCC71C5 1D8E78AF */
+/* Lp5 */	1.818357216161805012e-01,	/* 3FC74664 96CB03DE */
+/* Lp6 */	1.531383769920937332e-01,	/* 3FC39A09 D078C69F */
+/* Lp7 */	1.479819860511658591e-01,	/* 3FC2F112 DF3E5244 */
+/* zero */	0.0
+};
+#define	ln2_hi	xxx[0]
+#define	ln2_lo	xxx[1]
+#define	two54	xxx[2]
+#define	Lp1	xxx[3]
+#define	Lp2	xxx[4]
+#define	Lp3	xxx[5]
+#define	Lp4	xxx[6]
+#define	Lp5	xxx[7]
+#define	Lp6	xxx[8]
+#define	Lp7	xxx[9]
+#define	zero	xxx[10]
+
+double
+log1p(double x) {
+	double	hfsq, f, c = 0.0, s, z, R, u;
+	int	k, hx, hu, ax;
+
+	hx = ((int *)&x)[HIWORD];		/* high word of x */
+	ax = hx & 0x7fffffff;
+
+	if (ax >= 0x7ff00000) { /* x is inf or nan */
+		if (((hx - 0xfff00000) | ((int *)&x)[LOWORD]) == 0) /* -inf */
+			return (_SVID_libm_err(x, x, 44));
+		return (x * x);
+	}
+
+	k = 1;
+	if (hx < 0x3FDA827A) {	/* x < 0.41422  */
+		if (ax >= 0x3ff00000)	/* x <= -1.0 */
+			return (_SVID_libm_err(x, x, x == -1.0 ? 43 : 44));
+		if (ax < 0x3e200000) {	/* |x| < 2**-29 */
+			if (two54 + x > zero &&	/* raise inexact */
+			    ax < 0x3c900000)	/* |x| < 2**-54 */
+				return (x);
+			else
+				return (x - x * x * 0.5);
+		}
+		if (hx > 0 || hx <= (int)0xbfd2bec3) {	/* -0.2929<x<0.41422 */
+			k = 0;
+			f = x;
+			hu = 1;
+		}
+	}
+	/* We will initialize 'c' here. */
+	if (k != 0) {
+		if (hx < 0x43400000) {
+			u = 1.0 + x;
+			hu = ((int *)&u)[HIWORD];	/* high word of u */
+			k = (hu >> 20) - 1023;
+			/*
+			 * correction term
+			 */
+			c = k > 0 ? 1.0 - (u - x) : x - (u - 1.0);
+			c /= u;
+		} else {
+			u = x;
+			hu = ((int *)&u)[HIWORD];	/* high word of u */
+			k = (hu >> 20) - 1023;
+			c = 0;
+		}
+		hu &= 0x000fffff;
+		if (hu < 0x6a09e) {	/* normalize u */
+			((int *)&u)[HIWORD] = hu | 0x3ff00000;
+		} else {			/* normalize u/2 */
+			k += 1;
+			((int *)&u)[HIWORD] = hu | 0x3fe00000;
+			hu = (0x00100000 - hu) >> 2;
+		}
+		f = u - 1.0;
+	}
+	hfsq = 0.5 * f * f;
+	if (hu == 0) {		/* |f| < 2**-20 */
+		if (f == zero) {
+			if (k == 0)
+				return (zero);
+			/* We already initialized 'c' before, when (k != 0) */
+			c += k * ln2_lo;
+			return (k * ln2_hi + c);
+		}
+		R = hfsq * (1.0 - 0.66666666666666666 * f);
+		if (k == 0)
+			return (f - R);
+		return (k * ln2_hi - ((R - (k * ln2_lo + c)) - f));
+	}
+	s = f / (2.0 + f);
+	z = s * s;
+	R = z * (Lp1 + z * (Lp2 + z * (Lp3 + z * (Lp4 + z * (Lp5 +
+		z * (Lp6 + z * Lp7))))));
+	if (k == 0)
+		return (f - (hfsq - s * (hfsq + R)));
+	return (k * ln2_hi - ((hfsq - (s * (hfsq + R) +
+		(k * ln2_lo + c))) - f));
+}
