import newlib-2000-02-17 snapshot

1 files changed, 122 insertions, 0 deletions

diff --git a/newlib/libm/math/w_acosh.c b/newlib/libm/math/w_acosh.c
new file mode 100644
index 000000000..4120d7b12
--- /dev/null
+++ b/newlib/libm/math/w_acosh.c
@@ -0,0 +1,122 @@
+
+/* @(#)w_acosh.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
+<<acosh>>, <<acoshf>>---inverse hyperbolic cosine 
+
+INDEX
+acosh
+INDEX
+acoshf
+
+ANSI_SYNOPSIS
+	#include <math.h>
+	double acosh(double <[x]>);
+	float acoshf(float <[x]>);
+
+TRAD_SYNOPSIS
+	#include <math.h>
+	double acosh(<[x]>)
+	double <[x]>;
+
+	float acoshf(<[x]>)
+	float <[x]>;
+
+DESCRIPTION
+<<acosh>> calculates the inverse hyperbolic cosine of <[x]>.
+<<acosh>> is defined as 
+@ifinfo
+. log(<[x]> + sqrt(<[x]>*<[x]>-1))
+@end ifinfo
+@tex
+$$ln\Bigl(x + \sqrt{x^2-1}\Bigr)$$
+@end tex
+
+<[x]> must be a number greater than or equal to 1.
+
+<<acoshf>> is identical, other than taking and returning floats.
+
+RETURNS
+<<acosh>> and <<acoshf>> return the calculated value.  If <[x]> 
+less than 1, the return value is NaN and <<errno>> is set to <<EDOM>>.
+
+You can change the error-handling behavior with the non-ANSI
+<<matherr>> function.
+
+PORTABILITY
+Neither <<acosh>> nor <<acoshf>> are ANSI C.  They are not recommended
+for portable programs.
+
+
+QUICKREF ANSI SVID POSIX RENTRANT
+ acos	 n,n,n,m
+ acosf   n,n,n,m
+
+MATHREF  
+ acosh, NAN,   arg,DOMAIN,EDOM
+ acosh, < 1.0, NAN,DOMAIN,EDOM
+ acosh, >=1.0, acosh(arg),,,
+
+MATHREF
+ acoshf, NAN,   arg,DOMAIN,EDOM
+ acoshf, < 1.0, NAN,DOMAIN,EDOM
+ acoshf, >=1.0, acosh(arg),,,
+
+*/
+
+/* 
+ * wrapper acosh(x)
+ */
+
+#include "fdlibm.h"
+#include <errno.h>
+
+#ifndef _DOUBLE_IS_32BITS
+
+#ifdef __STDC__
+	double acosh(double x)		/* wrapper acosh */
+#else
+	double acosh(x)			/* wrapper acosh */
+	double x;
+#endif
+{
+#ifdef _IEEE_LIBM
+	return __ieee754_acosh(x);
+#else
+	double z;
+	struct exception exc;
+	z = __ieee754_acosh(x);
+	if(_LIB_VERSION == _IEEE_ || isnan(x)) return z;
+	if(x<1.0) {
+            /* acosh(x<1) */
+            exc.type = DOMAIN;
+            exc.name = "acosh";
+	    exc.err = 0;
+	    exc.arg1 = exc.arg2 = x;
+            exc.retval = 0.0/0.0;
+            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) */