--- /dev/null	Sat May 10 12:08:52 2014
+++ new/usr/src/lib/libm/common/C/hypot.c	Sat May 10 12:08:52 2014
@@ -0,0 +1,212 @@
+/*
+ * 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 2006 Sun Microsystems, Inc.  All rights reserved.
+ * Use is subject to license terms.
+ */
+
+#if defined(ELFOBJ)
+#pragma weak hypot = __hypot
+#endif
+
+/* INDENT OFF */
+/*
+ * Hypot(x, y)
+ * by K.C. Ng for SUN 4.0 libm, updated 3/11/2003.
+ * Method :
+ * A. When rounding is rounded-to-nearest:
+ *	If z = x * x + y * y has error less than sqrt(2) / 2 ulp than
+ *	sqrt(z) has error less than 1 ulp.
+ *	So, compute sqrt(x*x+y*y) with some care as follows:
+ *	Assume x > y > 0;
+ *	1. Check whether save and set rounding to round-to-nearest
+ *	2. if x > 2y  use
+ *		xh*xh+(y*y+((x-xh)*(x+xh))) for x*x+y*y
+ *	where xh = x with lower 32 bits cleared;  else
+ *	3. if x <= 2y use
+ *		x2h*yh+((x-y)*(x-y)+(x2h*(y-yh)+(x2-x2h)*y))
+ *	where x2 = 2*x, x2h = 2x with lower 32 bits cleared, yh = y with
+ *	lower 32 bits chopped.
+ *
+ * B. When rounding is not rounded-to-nearest:
+ *	The following (magic) formula will yield an error less than 1 ulp.
+ *	z = sqrt(x * x + y * y)
+ *		hypot(x, y) = x + (y / ((x + z) / y))
+ *
+ * NOTE: DO NOT remove parenthsis!
+ *
+ * Special cases:
+ *	hypot(x, y) is INF if x or y is +INF or -INF; else
+ *	hypot(x, y) is NAN if x or y is NAN.
+ *
+ * Accuracy:
+ * 	hypot(x, y) returns sqrt(x^2+y^2) with error less than 1 ulps
+ *	(units in the last place)
+ */
+
+#include "libm.h"
+
+static const double
+	zero = 0.0,
+	onep1u = 1.00000000000000022204e+00,	/* 0x3ff00000 1 = 1+2**-52 */
+	twom53 = 1.11022302462515654042e-16,	/* 0x3ca00000 0 = 2**-53 */
+	twom768 = 6.441148769597133308e-232,	/* 2^-768 */
+	two768  = 1.552518092300708935e+231;	/* 2^768 */
+
+/* INDENT ON */
+
+double
+hypot(double x, double y) {
+	double xh, yh, w, ax, ay;
+	int i, j, nx, ny, ix, iy, iscale = 0;
+	unsigned lx, ly;
+
+	ix = ((int *) &x)[HIWORD] & ~0x80000000;
+	lx = ((int *) &x)[LOWORD];
+	iy = ((int *) &y)[HIWORD] & ~0x80000000;
+	ly = ((int *) &y)[LOWORD];
+/*
+ * Force ax = |x| ~>~ ay = |y|
+ */
+	if (iy > ix) {
+		ax = fabs(y);
+		ay = fabs(x);
+		i = ix;
+		ix = iy;
+		iy = i;
+		i = lx;
+		lx = ly;
+		ly = i;
+	} else {
+		ax = fabs(x);
+		ay = fabs(y);
+	}
+	nx = ix >> 20;
+	ny = iy >> 20;
+	j  = nx - ny;
+/*
+ * x >= 2^500 (x*x or y*y may overflow)
+ */
+	if (nx >= 0x5f3) {
+		if (nx == 0x7ff) {	/* inf or NaN, signal of sNaN */
+			if (((ix - 0x7ff00000) | lx) == 0)
+				return (ax == ay ? ay : ax);
+			else if (((iy - 0x7ff00000) | ly) == 0)
+				return (ay == ax ? ax : ay);
+			else
+				return (ax * ay);	/* + -> * for Cheetah */
+		} else if (j > 32) {	/* x >> y */
+			if (j <= 53)
+				ay *= twom53;
+			ax += ay;
+			if (((int *) &ax)[HIWORD] == 0x7ff00000)
+				ax = _SVID_libm_err(x, y, 4);
+			return (ax);
+		}
+		ax *= twom768;
+		ay *= twom768;
+		iscale = 2;
+		ix -= 768 << 20;
+		iy -= 768 << 20;
+	}
+/*
+ * y < 2^-450 (x*x or y*y may underflow)
+ */
+	else if (ny < 0x23d) {
+		if ((ix | lx) == 0)
+			return (ay);
+		if ((iy | ly) == 0)
+			return (ax);
+		if (j > 53) 		/* x >> y */
+			return (ax + ay);
+		iscale = 1;
+		ax *= two768;
+		ay *= two768;
+		if (nx == 0) {
+			if (ax == zero)	/* guard subnormal flush to zero */
+				return (ax);
+			ix = ((int *) &ax)[HIWORD];
+		} else
+			ix += 768 << 20;
+		if (ny == 0) {
+			if (ay == zero)	/* guard subnormal flush to zero */
+				return (ax * twom768);
+			iy = ((int *) &ay)[HIWORD];
+		} else
+			iy += 768 << 20;
+		j = (ix >> 20) - (iy >> 20);
+		if (j > 32) {		/* x >> y */
+			if (j <= 53)
+				ay *= twom53;
+			return ((ax + ay) * twom768);
+		}
+	} else if (j > 32) {		/* x >> y */
+		if (j <= 53)
+			ay *= twom53;
+		return (ax + ay);
+	}
+/*
+ * Medium range ax and ay with max{|ax/ay|,|ay/ax|} bounded by 2^32
+ * First check rounding mode by comparing onep1u*onep1u with onep1u+twom53.
+ * Make sure the computation is done at run-time.
+ */
+	if (((lx | ly) << 5) == 0) {
+		ay = ay * ay;
+		ax += ay / (ax + sqrt(ax * ax + ay));
+	} else
+	if (onep1u * onep1u != onep1u + twom53) {
+	/* round-to-zero, positive, negative mode */
+	/* magic formula with less than an ulp error */
+		w = sqrt(ax * ax + ay * ay);
+		ax += ay / ((ax + w) / ay);
+	} else {
+	/* round-to-nearest mode */
+		w = ax - ay;
+		if (w > ay) {
+			((int *) &xh)[HIWORD] = ix;
+			((int *) &xh)[LOWORD] = 0;
+			ay = ay * ay + (ax - xh) * (ax + xh);
+			ax = sqrt(xh * xh + ay);
+		} else {
+			ax = ax + ax;
+			((int *) &xh)[HIWORD] = ix + 0x00100000;
+			((int *) &xh)[LOWORD] = 0;
+			((int *) &yh)[HIWORD] = iy;
+			((int *) &yh)[LOWORD] = 0;
+			ay = w * w + ((ax - xh) * yh + (ay - yh) * ax);
+			ax = sqrt(xh * yh + ay);
+		}
+	}
+	if (iscale > 0) {
+		if (iscale == 1)
+			ax *= twom768;
+		else {
+			ax *= two768;	/* must generate side effect here */
+			if (((int *) &ax)[HIWORD] == 0x7ff00000)
+				ax = _SVID_libm_err(x, y, 4);
+		}
+	}
+	return (ax);
+}
