1 files changed, 89 insertions, 0 deletions
diff --git a/newlib/libm/ld/e_acoshl.c b/newlib/libm/ld/e_acoshl.c
new file mode 100644
index 000000000..59faeb0fb
--- /dev/null
+++ b/newlib/libm/ld/e_acoshl.c
@@ -0,0 +1,89 @@
+/* from: FreeBSD: head/lib/msun/src/e_acosh.c 176451 2008-02-22 02:30:36Z das */
+
+/* @(#)e_acosh.c 1.3 95/01/18 */
+/*
+ * ====================================================
+ * Copyright (C) 1993 by Sun Microsystems, Inc. All rights reserved.
+ *
+ * Developed at SunSoft, a Sun Microsystems, Inc. business.
+ * Permission to use, copy, modify, and distribute this
+ * software is freely granted, provided that this notice
+ * is preserved.
+ * ====================================================
+ *
+ */
+
+#include <sys/cdefs.h>
+__FBSDID("$FreeBSD$");
+
+/*
+ * See e_acosh.c for complete comments.
+ *
+ * Converted to long double by David Schultz <das@FreeBSD.ORG> and
+ * Bruce D. Evans.
+ */
+
+#include <float.h>
+#ifdef __i386__
+#include <ieeefp.h>
+#endif
+
+#include "fpmath.h"
+#include "math.h"
+#include "math_private.h"
+
+/* EXP_LARGE is the threshold above which we use acosh(x) ~= log(2x). */
+#if LDBL_MANT_DIG == 64
+#define	EXP_LARGE	34
+#elif LDBL_MANT_DIG == 113
+#define	EXP_LARGE	58
+#else
+#error "Unsupported long double format"
+#endif
+
+#if LDBL_MAX_EXP != 0x4000
+/* We also require the usual expsign encoding. */
+#error "Unsupported long double format"
+#endif
+
+#define	BIAS	(LDBL_MAX_EXP - 1)
+
+static const double
+one	= 1.0;
+
+#if LDBL_MANT_DIG == 64
+static const union IEEEl2bits
+u_ln2 =  LD80C(0xb17217f7d1cf79ac, -1, 6.93147180559945309417e-1L);
+#define	ln2	u_ln2.e
+#elif LDBL_MANT_DIG == 113
+static const long double
+ln2 =  6.93147180559945309417232121458176568e-1L;	/* 0x162e42fefa39ef35793c7673007e6.0p-113 */
+#else
+#error "Unsupported long double format"
+#endif
+
+long double
+acoshl(long double x)
+{
+	long double t;
+	int16_t hx;
+
+	ENTERI();
+	GET_LDBL_EXPSIGN(hx, x);
+	if (hx < 0x3fff) {		/* x < 1, or misnormal */
+	    RETURNI((x-x)/(x-x));
+	} else if (hx >= BIAS + EXP_LARGE) { /* x >= LARGE */
+	    if (hx >= 0x7fff) {		/* x is inf, NaN or misnormal */
+	        RETURNI(x+x);
+	    } else
+		RETURNI(logl(x)+ln2);	/* acosh(huge)=log(2x), or misnormal */
+	} else if (hx == 0x3fff && x == 1) {
+	    RETURNI(0.0);		/* acosh(1) = 0 */
+	} else if (hx >= 0x4000) {	/* LARGE > x >= 2, or misnormal */
+	    t=x*x;
+	    RETURNI(logl(2.0*x-one/(x+sqrtl(t-one))));
+	} else {			/* 1<x<2 */
+	    t = x-one;
+	    RETURNI(log1pl(t+sqrtl(2.0*t+t*t)));
+	}
+}