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+
+/* @(#)w_asin.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.
+ * ====================================================
+ *
+ */
+
+/*
+FUNCTION
+ <<asin>>, <<asinf>>---arc sine
+
+INDEX
+ asin
+INDEX
+ asinf
+
+ANSI_SYNOPSIS
+ #include <math.h>
+ double asin(double <[x]>);
+ float asinf(float <[x]>);
+
+TRAD_SYNOPSIS
+ #include <math.h>
+ double asin(<[x]>)
+ double <[x]>;
+
+ float asinf(<[x]>)
+ float <[x]>;
+
+
+DESCRIPTION
+
+<<asin>> computes the inverse sine (arc sine) of the argument <[x]>.
+Arguments to <<asin>> must be in the range @minus{}1 to 1.
+
+<<asinf>> is identical to <<asin>>, other than taking and
+returning floats.
+
+You can modify error handling for these routines using <<matherr>>.
+
+RETURNS
+@ifinfo
+<<asin>> returns values in radians, in the range of -pi/2 to pi/2.
+@end ifinfo
+@tex
+<<asin>> returns values in radians, in the range of $-\pi/2$ to $\pi/2$.
+@end tex
+
+If <[x]> is not in the range @minus{}1 to 1, <<asin>> and <<asinf>>
+return NaN (not a number), set the global variable <<errno>> to
+<<EDOM>>, and issue a <<DOMAIN error>> message.
+
+You can change this error treatment using <<matherr>>.
+
+QUICKREF ANSI SVID POSIX RENTRANT
+ asin y,y,y,m
+ asinf n,n,n,m
+
+MATHREF
+ asin, -1<=arg<=1, asin(arg),,,
+ asin, NAN, arg,EDOM, DOMAIN
+
+MATHREF
+ asinf, -1<=arg<=1, asin(arg),,,
+ asinf, NAN, arg,EDOM, DOMAIN
+
+
+*/
+
+/*
+ * wrapper asin(x)
+ */
+
+
+#include "fdlibm.h"
+#include <errno.h>
+
+#ifndef _DOUBLE_IS_32BITS
+
+#ifdef __STDC__
+ double asin(double x) /* wrapper asin */
+#else
+ double asin(x) /* wrapper asin */
+ double x;
+#endif
+{
+#ifdef _IEEE_LIBM
+ return __ieee754_asin(x);
+#else
+ double z;
+ struct exception exc;
+ z = __ieee754_asin(x);
+ if(_LIB_VERSION == _IEEE_ || isnan(x)) return z;
+ if(fabs(x)>1.0) {
+ /* asin(|x|>1) */
+ exc.type = DOMAIN;
+ exc.name = "asin";
+ exc.err = 0;
+ exc.arg1 = exc.arg2 = x;
+ exc.retval = 0.0;
+ if(_LIB_VERSION == _POSIX_)
+ errno = EDOM;
+ else if (!matherr(&exc)) {
+ errno = EDOM;
+ }
+ if (exc.err != 0)
+ errno = exc.err;
+ return exc.retval;
+ } else
+ return z;
+#endif
+}
+
+#endif /* defined(_DOUBLE_IS_32BITS) */