initial import

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diff --git a/sysdeps/generic/asincos.c b/sysdeps/generic/asincos.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[] = "@(#)asincos.c	8.1 (Berkeley) 6/4/93";
+#endif /* not lint */
+
+/* ASIN(X)
+ * RETURNS ARC SINE 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 system supported functions:
+ *	copysign(x,y)
+ *	sqrt(x)
+ *
+ * Required kernel function:
+ *	atan2(y,x) 
+ *
+ * Method :                  
+ *	asin(x) = atan2(x,sqrt(1-x*x)); for better accuracy, 1-x*x is 
+ *		  computed as follows
+ *			1-x*x                     if x <  0.5, 
+ *			2*(1-|x|)-(1-|x|)*(1-|x|) if x >= 0.5.
+ *
+ * Special cases:
+ *	if x is NaN, return x itself;
+ *	if |x|>1, return NaN.
+ *
+ * Accuracy:
+ * 1)  If atan2() uses machine PI, then
+ * 
+ *	asin(x) returns (PI/pi) * (the exact arc sine 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
+ *	2.06 ulps.      (comparing against (PI/pi)*(exact asin(x)));
+ *
+ * 2)  If atan2() uses true pi, then
+ *
+ *	asin(x) returns the exact asin(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
+ *      1.99 ulps.
+ */
+
+double asin(x)
+double x;
+{
+	double s,t,copysign(),atan2(),sqrt(),one=1.0;
+#if !defined(vax)&&!defined(tahoe)
+	if(x!=x) return(x);	/* x is NaN */
+#endif	/* !defined(vax)&&!defined(tahoe) */
+	s=copysign(x,one);
+	if(s <= 0.5)
+	    return(atan2(x,sqrt(one-x*x)));
+	else 
+	    { t=one-s; s=t+t; return(atan2(x,sqrt(s-t*t))); }
+
+}
+
+/* ACOS(X)
+ * RETURNS ARC COS 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 system supported functions:
+ *	copysign(x,y)
+ *	sqrt(x)
+ *
+ * Required kernel function:
+ *	atan2(y,x) 
+ *
+ * Method :                  
+ *			      ________
+ *                           / 1 - x
+ *	acos(x) = 2*atan2(  / -------- , 1 ) .
+ *                        \/   1 + x
+ *
+ * Special cases:
+ *	if x is NaN, return x itself;
+ *	if |x|>1, return NaN.
+ *
+ * Accuracy:
+ * 1)  If atan2() uses machine PI, then
+ * 
+ *	acos(x) returns (PI/pi) * (the exact arc cosine 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
+ *	2.07 ulps.      (comparing against (PI/pi)*(exact acos(x)));
+ *
+ * 2)  If atan2() uses true pi, then
+ *
+ *	acos(x) returns the exact acos(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
+ *	2.15 ulps.
+ */
+
+double acos(x)
+double x;
+{
+	double t,copysign(),atan2(),sqrt(),one=1.0;
+#if !defined(vax)&&!defined(tahoe)
+	if(x!=x) return(x);
+#endif	/* !defined(vax)&&!defined(tahoe) */
+	if( x != -1.0)
+	    t=atan2(sqrt((one-x)/(one+x)),one);
+	else
+	    t=atan2(one,0.0);	/* t = PI/2 */
+	return(t+t);
+}