1 files changed, 91 insertions, 0 deletions
diff --git a/src/math/acosl.c b/src/math/acosl.c
new file mode 100644
index 00000000..21e6c95e
--- /dev/null
+++ b/src/math/acosl.c
@@ -0,0 +1,91 @@
+/* origin: FreeBSD /usr/src/lib/msun/src/e_acosl.c */
+/*
+ * ====================================================
+ * 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.
+ * ====================================================
+ */
+/*
+ * See comments in acos.c.
+ * Converted to long double by David Schultz <das@FreeBSD.ORG>.
+ */
+
+#include "libm.h"
+
+#if LDBL_MANT_DIG == 53 && LDBL_MAX_EXP == 1024
+long double acosl(long double x)
+{
+	return acos(x);
+}
+#elif (LDBL_MANT_DIG == 64 || LDBL_MANT_DIG == 113) && LDBL_MAX_EXP == 16384
+#include "__invtrigl.h"
+
+static const long double
+one = 1.00000000000000000000e+00;
+
+// FIXME
+//#ifdef __i386__
+/* XXX Work around the fact that gcc truncates long double constants on i386 */
+static volatile double
+pi1 = 3.14159265358979311600e+00, /* 0x1.921fb54442d18p+1 */
+pi2 = 1.22514845490862001043e-16; /* 0x1.1a80000000000p-53 */
+#define pi ((long double)pi1 + pi2)
+//#else
+#if 0
+static const long double
+pi = 3.14159265358979323846264338327950280e+00L;
+#endif
+
+long double acosl(long double x)
+{
+	union IEEEl2bits u;
+	long double z, p, q, r, w, s, c, df;
+	int16_t expsign, expt;
+	u.e = x;
+	expsign = u.xbits.expsign;
+	expt = expsign & 0x7fff;
+	if (expt >= BIAS) {        /* |x| >= 1 */
+		if (expt == BIAS &&
+			((u.bits.manh & ~LDBL_NBIT) | u.bits.manl) == 0) {
+			if (expsign > 0)
+				return 0.0;  /* acos(1) = 0 */
+			else
+				return pi + 2.0 * pio2_lo;  /* acos(-1)= pi */
+		}
+		return (x - x) / (x - x);  /* acos(|x|>1) is NaN */
+	}
+	if (expt < BIAS - 1) {     /* |x| < 0.5 */
+		if (expt < ACOS_CONST)
+			return pio2_hi + pio2_lo;  /* x tiny: acosl=pi/2 */
+		z = x * x;
+		p = P(z);
+		q = Q(z);
+		r = p / q;
+		return pio2_hi - (x - (pio2_lo - x * r));
+	} else if (expsign < 0) {  /* x < -0.5 */
+		z = (one + x) * 0.5;
+		p = P(z);
+		q = Q(z);
+		s = sqrtl(z);
+		r = p / q;
+		w = r * s - pio2_lo;
+		return pi - 2.0 * (s + w);
+	} else {                   /* x > 0.5 */
+		z = (one - x) * 0.5;
+		s = sqrtl(z);
+		u.e = s;
+		u.bits.manl = 0;
+		df = u.e;
+		c = (z - df * df) / (s + df);
+		p = P(z);
+		q = Q(z);
+		r = p / q;
+		w = r * s + c;
+		return 2.0 * (df + w);
+	}
+}
+#endif