From abfbdde177c3a7155070dda1b2cdc8292054cc26 Mon Sep 17 00:00:00 2001
From: Ulrich Drepper <drepper@redhat.com>
Date: Wed, 14 Jul 1999 00:54:57 +0000
Subject: Update.

---
 sysdeps/ieee754/flt-32/e_logf.c | 99 +++++++++++++++++++++++++++++++++++++++++
 1 file changed, 99 insertions(+)
 create mode 100644 sysdeps/ieee754/flt-32/e_logf.c

(limited to 'sysdeps/ieee754/flt-32/e_logf.c')

diff --git a/sysdeps/ieee754/flt-32/e_logf.c b/sysdeps/ieee754/flt-32/e_logf.c
new file mode 100644
index 0000000000..de8f869df4
--- /dev/null
+++ b/sysdeps/ieee754/flt-32/e_logf.c
@@ -0,0 +1,99 @@
+/* e_logf.c -- float version of e_log.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_logf.c,v 1.4 1995/05/10 20:45:54 jtc Exp $";
+#endif
+
+#include "math.h"
+#include "math_private.h"
+
+#ifdef __STDC__
+static const float
+#else
+static float
+#endif
+ln2_hi =   6.9313812256e-01,	/* 0x3f317180 */
+ln2_lo =   9.0580006145e-06,	/* 0x3717f7d1 */
+two25 =    3.355443200e+07,	/* 0x4c000000 */
+Lg1 = 6.6666668653e-01,	/* 3F2AAAAB */
+Lg2 = 4.0000000596e-01,	/* 3ECCCCCD */
+Lg3 = 2.8571429849e-01, /* 3E924925 */
+Lg4 = 2.2222198546e-01, /* 3E638E29 */
+Lg5 = 1.8183572590e-01, /* 3E3A3325 */
+Lg6 = 1.5313838422e-01, /* 3E1CD04F */
+Lg7 = 1.4798198640e-01; /* 3E178897 */
+
+#ifdef __STDC__
+static const float zero   =  0.0;
+#else
+static float zero   =  0.0;
+#endif
+
+#ifdef __STDC__
+	float __ieee754_logf(float x)
+#else
+	float __ieee754_logf(x)
+	float x;
+#endif
+{
+	float hfsq,f,s,z,R,w,t1,t2,dk;
+	int32_t k,ix,i,j;
+
+	GET_FLOAT_WORD(ix,x);
+
+	k=0;
+	if (ix < 0x00800000) {			/* x < 2**-126  */
+	    if ((ix&0x7fffffff)==0)
+		return -two25/(x-x);		/* log(+-0)=-inf */
+	    if (ix<0) return (x-x)/(x-x);	/* log(-#) = NaN */
+	    k -= 25; x *= two25; /* subnormal number, scale up x */
+	    GET_FLOAT_WORD(ix,x);
+	}
+	if (ix >= 0x7f800000) return x+x;
+	k += (ix>>23)-127;
+	ix &= 0x007fffff;
+	i = (ix+(0x95f64<<3))&0x800000;
+	SET_FLOAT_WORD(x,ix|(i^0x3f800000));	/* normalize x or x/2 */
+	k += (i>>23);
+	f = x-(float)1.0;
+	if((0x007fffff&(15+ix))<16) {	/* |f| < 2**-20 */
+	    if(f==zero) {
+	      if(k==0) return zero;  else {dk=(float)k;
+					   return dk*ln2_hi+dk*ln2_lo;}
+	    }
+	    R = f*f*((float)0.5-(float)0.33333333333333333*f);
+	    if(k==0) return f-R; else {dk=(float)k;
+	    	     return dk*ln2_hi-((R-dk*ln2_lo)-f);}
+	}
+ 	s = f/((float)2.0+f);
+	dk = (float)k;
+	z = s*s;
+	i = ix-(0x6147a<<3);
+	w = z*z;
+	j = (0x6b851<<3)-ix;
+	t1= w*(Lg2+w*(Lg4+w*Lg6));
+	t2= z*(Lg1+w*(Lg3+w*(Lg5+w*Lg7)));
+	i |= j;
+	R = t2+t1;
+	if(i>0) {
+	    hfsq=(float)0.5*f*f;
+	    if(k==0) return f-(hfsq-s*(hfsq+R)); else
+		     return dk*ln2_hi-((hfsq-(s*(hfsq+R)+dk*ln2_lo))-f);
+	} else {
+	    if(k==0) return f-s*(f-R); else
+		     return dk*ln2_hi-((s*(f-R)-dk*ln2_lo)-f);
+	}
+}
-- 
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