1 files changed, 64 insertions, 0 deletions
diff --git a/src/math/asinf.c b/src/math/asinf.c
new file mode 100644
index 00000000..729dd37f
--- /dev/null
+++ b/src/math/asinf.c
@@ -0,0 +1,64 @@
+/* origin: FreeBSD /usr/src/lib/msun/src/e_asinf.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.
+ * ====================================================
+ */
+
+#include "libm.h"
+
+static const float
+one =  1.0000000000e+00, /* 0x3F800000 */
+huge = 1.000e+30,
+/* coefficients for R(x^2) */
+pS0 =  1.6666586697e-01,
+pS1 = -4.2743422091e-02,
+pS2 = -8.6563630030e-03,
+qS1 = -7.0662963390e-01;
+
+static const double
+pio2 = 1.570796326794896558e+00;
+
+float asinf(float x)
+{
+	double s;
+	float t,w,p,q;
+	int32_t hx,ix;
+
+	GET_FLOAT_WORD(hx, x);
+	ix = hx & 0x7fffffff;
+	if (ix >= 0x3f800000) {  /* |x| >= 1 */
+		if (ix == 0x3f800000)  /* |x| == 1 */
+			return x*pio2;  /* asin(+-1) = +-pi/2 with inexact */
+		return (x-x)/(x-x);  /* asin(|x|>1) is NaN */
+	} else if (ix < 0x3f000000) {  /* |x|<0.5 */
+		if (ix < 0x39800000) {  /* |x| < 2**-12 */
+			if (huge+x > one)
+				return x; /* return x with inexact if x!=0 */
+		}
+		t = x*x;
+		p = t*(pS0+t*(pS1+t*pS2));
+		q = one+t*qS1;
+		w = p/q;
+		return x + x*w;
+	}
+	/* 1 > |x| >= 0.5 */
+	w = one - fabsf(x);
+	t = w*(float)0.5;
+	p = t*(pS0+t*(pS1+t*pS2));
+	q = one+t*qS1;
+	s = sqrt(t);
+	w = p/q;
+	t = pio2-2.0*(s+s*w);
+	if (hx > 0)
+		return t;
+	return -t;
+}