Initial revision

From-SVN: r26263

libjava/java/lang/w_acos.c

@@ -0,0 +1,118 @@
+
+/* @(#)w_acos.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
+        <<acos>>, <<acosf>>---arc cosine
+
+INDEX
+	acos
+INDEX
+	acosf
+
+ANSI_SYNOPSIS
+        #include <math.h>
+        double acos(double <[x]>);
+        float acosf(float <[x]>);
+
+TRAD_SYNOPSIS
+        #include <math.h>
+        double acos(<[x]>)
+        double <[x]>;
+
+        float acosf(<[x]>)
+        float <[x]>;
+
+
+
+DESCRIPTION
+
+	<<acos>> computes the inverse cosine (arc cosine) of the input value.
+	Arguments to <<acos>> must be in the range @minus{}1 to 1. 
+
+	<<acosf>> is identical to <<acos>>, except that it performs
+	its calculations on <<floats>>.
+
+RETURNS
+	@ifinfo
+	<<acos>> and <<acosf>> return values in radians, in the range of 0 to pi.
+	@end ifinfo
+	@tex
+	<<acos>> and <<acosf>> return values in radians, in the range of <<0>> to $\pi$.
+	@end tex
+
+	If <[x]> is not between @minus{}1 and 1, the returned value is NaN
+	(not a number) the global variable <<errno>> is set to <<EDOM>>, and a
+	<<DOMAIN error>> message is sent as standard error output.
+
+	You can modify error handling for these functions using <<matherr>>.
+
+
+QUICKREF ANSI SVID POSIX RENTRANT
+ acos	 y,y,y,m
+ acosf   n,n,n,m
+
+MATHREF  
+ acos, [-1,1], acos(arg),,,
+ acos, NAN,    arg,DOMAIN,EDOM
+
+MATHREF
+ acosf, [-1,1], acosf(arg),,,
+ acosf, NAN,    argf,DOMAIN,EDOM
+ 
+*/
+
+/*
+ * wrap_acos(x)
+ */
+
+#include "fdlibm.h"
+#include <errno.h>
+
+#ifndef _DOUBLE_IS_32BITS
+
+#ifdef __STDC__
+	double acos(double x)		/* wrapper acos */
+#else
+	double acos(x)			/* wrapper acos */
+	double x;
+#endif
+{
+#ifdef _IEEE_LIBM
+	return __ieee754_acos(x);
+#else
+	double z;
+       	struct exception exc;
+       	z = __ieee754_acos(x);
+	if(_LIB_VERSION == _IEEE_ || isnan(x)) return z;
+	if(fabs(x)>1.0) { 
+	    /* acos(|x|>1) */
+	    exc.type = DOMAIN;
+	    exc.name = "acos";
+	    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) */