Update.

1 files changed, 213 insertions, 0 deletions

diff --git a/sysdeps/ieee754/flt-32/e_jnf.c b/sysdeps/ieee754/flt-32/e_jnf.c
new file mode 100644
index 0000000000..9e5279c30a
--- /dev/null
+++ b/sysdeps/ieee754/flt-32/e_jnf.c
@@ -0,0 +1,213 @@
+/* e_jnf.c -- float version of e_jn.c.
+ * Conversion to float by Ian Lance Taylor, Cygnus Support, ian@cygnus.com.
+ */
+
+/*
+ * ====================================================
+ * 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.
+ * ====================================================
+ */
+
+#if defined(LIBM_SCCS) && !defined(lint)
+static char rcsid[] = "$NetBSD: e_jnf.c,v 1.5 1995/05/10 20:45:37 jtc Exp $";
+#endif
+
+#include "math.h"
+#include "math_private.h"
+
+#ifdef __STDC__
+static const float
+#else
+static float
+#endif
+invsqrtpi=  5.6418961287e-01, /* 0x3f106ebb */
+two   =  2.0000000000e+00, /* 0x40000000 */
+one   =  1.0000000000e+00; /* 0x3F800000 */
+
+#ifdef __STDC__
+static const float zero  =  0.0000000000e+00;
+#else
+static float zero  =  0.0000000000e+00;
+#endif
+
+#ifdef __STDC__
+	float __ieee754_jnf(int n, float x)
+#else
+	float __ieee754_jnf(n,x)
+	int n; float x;
+#endif
+{
+	int32_t i,hx,ix, sgn;
+	float a, b, temp, di;
+	float z, w;
+
+    /* J(-n,x) = (-1)^n * J(n, x), J(n, -x) = (-1)^n * J(n, x)
+     * Thus, J(-n,x) = J(n,-x)
+     */
+	GET_FLOAT_WORD(hx,x);
+	ix = 0x7fffffff&hx;
+    /* if J(n,NaN) is NaN */
+	if(ix>0x7f800000) return x+x;
+	if(n<0){
+		n = -n;
+		x = -x;
+		hx ^= 0x80000000;
+	}
+	if(n==0) return(__ieee754_j0f(x));
+	if(n==1) return(__ieee754_j1f(x));
+	sgn = (n&1)&(hx>>31);	/* even n -- 0, odd n -- sign(x) */
+	x = fabsf(x);
+	if(ix==0||ix>=0x7f800000) 	/* if x is 0 or inf */
+	    b = zero;
+	else if((float)n<=x) {
+		/* Safe to use J(n+1,x)=2n/x *J(n,x)-J(n-1,x) */
+	    a = __ieee754_j0f(x);
+	    b = __ieee754_j1f(x);
+	    for(i=1;i<n;i++){
+		temp = b;
+		b = b*((float)(i+i)/x) - a; /* avoid underflow */
+		a = temp;
+	    }
+	} else {
+	    if(ix<0x30800000) {	/* x < 2**-29 */
+    /* x is tiny, return the first Taylor expansion of J(n,x)
+     * J(n,x) = 1/n!*(x/2)^n  - ...
+     */
+		if(n>33)	/* underflow */
+		    b = zero;
+		else {
+		    temp = x*(float)0.5; b = temp;
+		    for (a=one,i=2;i<=n;i++) {
+			a *= (float)i;		/* a = n! */
+			b *= temp;		/* b = (x/2)^n */
+		    }
+		    b = b/a;
+		}
+	    } else {
+		/* use backward recurrence */
+		/* 			x      x^2      x^2
+		 *  J(n,x)/J(n-1,x) =  ----   ------   ------   .....
+		 *			2n  - 2(n+1) - 2(n+2)
+		 *
+		 * 			1      1        1
+		 *  (for large x)   =  ----  ------   ------   .....
+		 *			2n   2(n+1)   2(n+2)
+		 *			-- - ------ - ------ -
+		 *			 x     x         x
+		 *
+		 * Let w = 2n/x and h=2/x, then the above quotient
+		 * is equal to the continued fraction:
+		 *		    1
+		 *	= -----------------------
+		 *		       1
+		 *	   w - -----------------
+		 *			  1
+		 * 	        w+h - ---------
+		 *		       w+2h - ...
+		 *
+		 * To determine how many terms needed, let
+		 * Q(0) = w, Q(1) = w(w+h) - 1,
+		 * Q(k) = (w+k*h)*Q(k-1) - Q(k-2),
+		 * When Q(k) > 1e4	good for single
+		 * When Q(k) > 1e9	good for double
+		 * When Q(k) > 1e17	good for quadruple
+		 */
+	    /* determine k */
+		float t,v;
+		float q0,q1,h,tmp; int32_t k,m;
+		w  = (n+n)/(float)x; h = (float)2.0/(float)x;
+		q0 = w;  z = w+h; q1 = w*z - (float)1.0; k=1;
+		while(q1<(float)1.0e9) {
+			k += 1; z += h;
+			tmp = z*q1 - q0;
+			q0 = q1;
+			q1 = tmp;
+		}
+		m = n+n;
+		for(t=zero, i = 2*(n+k); i>=m; i -= 2) t = one/(i/x-t);
+		a = t;
+		b = one;
+		/*  estimate log((2/x)^n*n!) = n*log(2/x)+n*ln(n)
+		 *  Hence, if n*(log(2n/x)) > ...
+		 *  single 8.8722839355e+01
+		 *  double 7.09782712893383973096e+02
+		 *  long double 1.1356523406294143949491931077970765006170e+04
+		 *  then recurrent value may overflow and the result is
+		 *  likely underflow to zero
+		 */
+		tmp = n;
+		v = two/x;
+		tmp = tmp*__ieee754_logf(fabsf(v*tmp));
+		if(tmp<(float)8.8721679688e+01) {
+	    	    for(i=n-1,di=(float)(i+i);i>0;i--){
+		        temp = b;
+			b *= di;
+			b  = b/x - a;
+		        a = temp;
+			di -= two;
+	     	    }
+		} else {
+	    	    for(i=n-1,di=(float)(i+i);i>0;i--){
+		        temp = b;
+			b *= di;
+			b  = b/x - a;
+		        a = temp;
+			di -= two;
+		    /* scale b to avoid spurious overflow */
+			if(b>(float)1e10) {
+			    a /= b;
+			    t /= b;
+			    b  = one;
+			}
+	     	    }
+		}
+	    	b = (t*__ieee754_j0f(x)/b);
+	    }
+	}
+	if(sgn==1) return -b; else return b;
+}
+
+#ifdef __STDC__
+	float __ieee754_ynf(int n, float x)
+#else
+	float __ieee754_ynf(n,x)
+	int n; float x;
+#endif
+{
+	int32_t i,hx,ix;
+	u_int32_t ib;
+	int32_t sign;
+	float a, b, temp;
+
+	GET_FLOAT_WORD(hx,x);
+	ix = 0x7fffffff&hx;
+    /* if Y(n,NaN) is NaN */
+	if(ix>0x7f800000) return x+x;
+	if(ix==0) return -one/zero;
+	if(hx<0) return zero/zero;
+	sign = 1;
+	if(n<0){
+		n = -n;
+		sign = 1 - ((n&1)<<1);
+	}
+	if(n==0) return(__ieee754_y0f(x));
+	if(n==1) return(sign*__ieee754_y1f(x));
+	if(ix==0x7f800000) return zero;
+
+	a = __ieee754_y0f(x);
+	b = __ieee754_y1f(x);
+	/* quit if b is -inf */
+	GET_FLOAT_WORD(ib,b);
+	for(i=1;i<n&&ib!=0xff800000;i++){
+	    temp = b;
+	    b = ((float)(i+i)/x)*b - a;
+	    GET_FLOAT_WORD(ib,b);
+	    a = temp;
+	}
+	if(sign>0) return b; else return -b;
+}