1 files changed, 72 insertions, 0 deletions
diff --git a/sysdeps/libm-ieee754/e_acoshl.c b/sysdeps/libm-ieee754/e_acoshl.c
new file mode 100644
index 0000000000..8af7c27aa7
--- /dev/null
+++ b/sysdeps/libm-ieee754/e_acoshl.c
@@ -0,0 +1,72 @@
+/* e_acoshl.c -- long double version of e_acosh.c.
+ * Conversion to long double by Ulrich Drepper,
+ * Cygnus Support, drepper@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: $";
+#endif
+
+/* __ieee754_acoshl(x)
+ * Method :
+ *	Based on
+ *		acoshl(x) = logl [ x + sqrtl(x*x-1) ]
+ *	we have
+ *		acoshl(x) := logl(x)+ln2,	if x is large; else
+ *		acoshl(x) := logl(2x-1/(sqrtl(x*x-1)+x)) if x>2; else
+ *		acoshl(x) := log1pl(t+sqrtl(2.0*t+t*t)); where t=x-1.
+ *
+ * Special cases:
+ *	acoshl(x) is NaN with signal if x<1.
+ *	acoshl(NaN) is NaN without signal.
+ */
+
+#include "math.h"
+#include "math_private.h"
+
+#ifdef __STDC__
+static const long double
+#else
+static long double
+#endif
+one	= 1.0,
+ln2	= 6.931471805599453094287e-01L; /* 0x3FFE, 0xB17217F7, 0xD1CF79AC */
+
+#ifdef __STDC__
+	long double __ieee754_acoshl(long double x)
+#else
+	long double __ieee754_acoshl(x)
+	long double x;
+#endif
+{
+	long double t;
+	u_int32_t se,i0,i1;
+	EXTRACT_LDOUBLE_WORDS(se,i0,i1,x);
+	if(se<0x3fff) {			/* x < 1 */
+	    return (x-x)/(x-x);
+	} else if(hx >=0x401b) {	/* x > 2**28 */
+	    if(hx >=0x7fff) {		/* x is inf of NaN */
+	        return x+x;
+	    } else
+		return __ieee754_logl(x)+ln2;	/* acoshl(huge)=logl(2x) */
+	} else if(((se-0x3fff)|i0|i1)==0) {
+	    return 0.0;			/* acosh(1) = 0 */
+	} else if (hx > 0x4000) {	/* 2**28 > x > 2 */
+	    t=x*x;
+	    return __ieee754_logl(2.0*x-one/(x+__ieee754_sqrtl(t-one)));
+	} else {			/* 1<x<2 */
+	    t = x-one;
+	    return __log1pl(t+__sqrtl(2.0*t+t*t));
+	}
+}