1 files changed, 76 insertions, 0 deletions
diff --git a/modules/fdlibm/src/e_acosf.cpp b/modules/fdlibm/src/e_acosf.cpp
new file mode 100644
index 0000000000..79f07a98b0
--- /dev/null
+++ b/modules/fdlibm/src/e_acosf.cpp
@@ -0,0 +1,76 @@
+/* e_acosf.c -- float version of e_acos.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 <sys/cdefs.h>
+//__FBSDID("$FreeBSD$");
+
+#include "math_private.h"
+
+static const float
+one =  1.0000000000e+00, /* 0x3F800000 */
+pi =  3.1415925026e+00, /* 0x40490fda */
+pio2_hi =  1.5707962513e+00; /* 0x3fc90fda */
+static volatile float
+pio2_lo =  7.5497894159e-08; /* 0x33a22168 */
+static const float
+pS0 =  1.6666586697e-01,
+pS1 = -4.2743422091e-02,
+pS2 = -8.6563630030e-03,
+qS1 = -7.0662963390e-01;
+
+float
+__ieee754_acosf(float x)
+{
+	float z,p,q,r,w,s,c,df;
+	int32_t hx,ix;
+	GET_FLOAT_WORD(hx,x);
+	ix = hx&0x7fffffff;
+	if(ix>=0x3f800000) {		/* |x| >= 1 */
+	    if(ix==0x3f800000) {	/* |x| == 1 */
+		if(hx>0) return 0.0;	/* acos(1) = 0 */
+		else return pi+(float)2.0*pio2_lo;	/* acos(-1)= pi */
+	    }
+	    return (x-x)/(x-x);		/* acos(|x|>1) is NaN */
+	}
+	if(ix<0x3f000000) {	/* |x| < 0.5 */
+	    if(ix<=0x32800000) return pio2_hi+pio2_lo;/*if|x|<2**-26*/
+	    z = x*x;
+	    p = z*(pS0+z*(pS1+z*pS2));
+	    q = one+z*qS1;
+	    r = p/q;
+	    return pio2_hi - (x - (pio2_lo-x*r));
+	} else  if (hx<0) {		/* x < -0.5 */
+	    z = (one+x)*(float)0.5;
+	    p = z*(pS0+z*(pS1+z*pS2));
+	    q = one+z*qS1;
+	    s = sqrtf(z);
+	    r = p/q;
+	    w = r*s-pio2_lo;
+	    return pi - (float)2.0*(s+w);
+	} else {			/* x > 0.5 */
+	    int32_t idf;
+	    z = (one-x)*(float)0.5;
+	    s = sqrtf(z);
+	    df = s;
+	    GET_FLOAT_WORD(idf,df);
+	    SET_FLOAT_WORD(df,idf&0xfffff000);
+	    c  = (z-df*df)/(s+df);
+	    p = z*(pS0+z*(pS1+z*pS2));
+	    q = one+z*qS1;
+	    r = p/q;
+	    w = r*s+c;
+	    return (float)2.0*(df+w);
+	}
+}