import newlib-2000-02-17 snapshot

1 files changed, 141 insertions, 0 deletions

diff --git a/newlib/libm/math/w_jn.c b/newlib/libm/math/w_jn.c
new file mode 100644
index 000000000..6cadc9a01
--- /dev/null
+++ b/newlib/libm/math/w_jn.c
@@ -0,0 +1,141 @@
+
+/* @(#)w_jn.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.
+ * ====================================================
+ */
+
+/*
+ * wrapper jn(int n, double x), yn(int n, double x)
+ * floating point Bessel's function of the 1st and 2nd kind
+ * of order n
+ *          
+ * Special cases:
+ *	y0(0)=y1(0)=yn(n,0) = -inf with division by zero signal;
+ *	y0(-ve)=y1(-ve)=yn(n,-ve) are NaN with invalid signal.
+ * Note 2. About jn(n,x), yn(n,x)
+ *	For n=0, j0(x) is called,
+ *	for n=1, j1(x) is called,
+ *	for n<x, forward recursion us used starting
+ *	from values of j0(x) and j1(x).
+ *	for n>x, a continued fraction approximation to
+ *	j(n,x)/j(n-1,x) is evaluated and then backward
+ *	recursion is used starting from a supposed value
+ *	for j(n,x). The resulting value of j(0,x) is
+ *	compared with the actual value to correct the
+ *	supposed value of j(n,x).
+ *
+ *	yn(n,x) is similar in all respects, except
+ *	that forward recursion is used for all
+ *	values of n>1.
+ *	
+ */
+
+#include "fdlibm.h"
+#include <errno.h>
+
+#ifndef _DOUBLE_IS_32BITS
+
+#ifdef __STDC__
+	double jn(int n, double x)	/* wrapper jn */
+#else
+	double jn(n,x)			/* wrapper jn */
+	double x; int n;
+#endif
+{
+#ifdef _IEEE_LIBM
+	return __ieee754_jn(n,x);
+#else
+	double z;
+	struct exception exc;
+	z = __ieee754_jn(n,x);
+	if(_LIB_VERSION == _IEEE_ || isnan(x) ) return z;
+	if(fabs(x)>X_TLOSS) {
+	    /* jn(|x|>X_TLOSS) */
+            exc.type = TLOSS;
+            exc.name = "jn";
+	    exc.err = 0;
+	    exc.arg1 = n;
+	    exc.arg2 = x;
+            exc.retval = 0.0;
+            if (_LIB_VERSION == _POSIX_)
+                errno = ERANGE;
+            else if (!matherr(&exc)) {
+               errno = ERANGE;
+            }        
+	    if (exc.err != 0)
+	       errno = exc.err;
+            return exc.retval; 
+	} else
+	    return z;
+#endif
+}
+
+#ifdef __STDC__
+	double yn(int n, double x)	/* wrapper yn */
+#else
+	double yn(n,x)			/* wrapper yn */
+	double x; int n;
+#endif
+{
+#ifdef _IEEE_LIBM
+	return __ieee754_yn(n,x);
+#else
+	double z;
+	struct exception exc;
+	z = __ieee754_yn(n,x);
+	if(_LIB_VERSION == _IEEE_ || isnan(x) ) return z;
+        if(x <= 0.0){
+	    /* yn(n,0) = -inf or yn(x<0) = NaN */
+#ifndef HUGE_VAL 
+#define HUGE_VAL inf
+	    double inf = 0.0;
+
+	    SET_HIGH_WORD(inf,0x7ff00000);	/* set inf to infinite */
+#endif
+	    exc.type = DOMAIN;	/* should be SING for IEEE */
+	    exc.name = "yn";
+	    exc.err = 0;
+	    exc.arg1 = n;
+	    exc.arg2 = x;
+	    if (_LIB_VERSION == _SVID_)
+	        exc.retval = -HUGE;
+	    else
+	        exc.retval = -HUGE_VAL;
+	    if (_LIB_VERSION == _POSIX_)
+	        errno = EDOM;
+	    else if (!matherr(&exc)) {
+	        errno = EDOM;
+	    }
+	    if (exc.err != 0)
+	       errno = exc.err;
+            return exc.retval; 
+        }
+	if(x>X_TLOSS) {
+	    /* yn(x>X_TLOSS) */
+            exc.type = TLOSS;
+            exc.name = "yn";
+	    exc.err = 0;
+	    exc.arg1 = n;
+	    exc.arg2 = x;
+            exc.retval = 0.0;
+            if (_LIB_VERSION == _POSIX_)
+                errno = ERANGE;
+            else if (!matherr(&exc)) {
+                errno = ERANGE;
+            }        
+	    if (exc.err != 0)
+	       errno = exc.err;
+            return exc.retval; 
+	} else
+	    return z;
+#endif
+}
+
+#endif /* defined(_DOUBLE_IS_32BITS) */