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diff --git a/lib/libm/common_source/atan.c b/lib/libm/common_source/atan.c
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+/*
+ * Copyright (c) 1985, 1993
+ *	The Regents of the University of California.  All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ * 3. All advertising materials mentioning features or use of this software
+ *    must display the following acknowledgement:
+ *	This product includes software developed by the University of
+ *	California, Berkeley and its contributors.
+ * 4. Neither the name of the University nor the names of its contributors
+ *    may be used to endorse or promote products derived from this software
+ *    without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ */
+
+#ifndef lint
+static char sccsid[] = "@(#)atan.c	8.1 (Berkeley) 6/4/93";
+#endif /* not lint */
+
+/* ATAN(X)
+ * RETURNS ARC TANGENT OF X
+ * DOUBLE PRECISION (IEEE DOUBLE 53 bits, VAX D FORMAT 56 bits)
+ * CODED IN C BY K.C. NG, 4/16/85, REVISED ON 6/10/85.
+ *
+ * Required kernel function:
+ *	atan2(y,x)
+ *
+ * Method:
+ *	atan(x) = atan2(x,1.0).
+ *
+ * Special case:
+ *	if x is NaN, return x itself.
+ *
+ * Accuracy:
+ * 1)  If atan2() uses machine PI, then
+ *
+ *	atan(x) returns (PI/pi) * (the exact arc tangent of x) nearly rounded;
+ *	and PI is the exact pi rounded to machine precision (see atan2 for
+ *      details):
+ *
+ *	in decimal:
+ *		pi = 3.141592653589793 23846264338327 .....
+ *    53 bits   PI = 3.141592653589793 115997963 ..... ,
+ *    56 bits   PI = 3.141592653589793 227020265 ..... ,
+ *
+ *	in hexadecimal:
+ *		pi = 3.243F6A8885A308D313198A2E....
+ *    53 bits   PI = 3.243F6A8885A30  =  2 * 1.921FB54442D18	error=.276ulps
+ *    56 bits   PI = 3.243F6A8885A308 =  4 * .C90FDAA22168C2    error=.206ulps
+ *
+ *	In a test run with more than 200,000 random arguments on a VAX, the
+ *	maximum observed error in ulps (units in the last place) was
+ *	0.86 ulps.      (comparing against (PI/pi)*(exact atan(x))).
+ *
+ * 2)  If atan2() uses true pi, then
+ *
+ *	atan(x) returns the exact atan(x) with error below about 2 ulps.
+ *
+ *	In a test run with more than 1,024,000 random arguments on a VAX, the
+ *	maximum observed error in ulps (units in the last place) was
+ *	0.85 ulps.
+ */
+
+double atan(x)
+double x;
+{
+	double atan2(),one=1.0;
+	return(atan2(x,one));
+}