Index: fusl/src/math/atanf.c |
diff --git a/fusl/src/math/atanf.c b/fusl/src/math/atanf.c |
new file mode 100644 |
index 0000000000000000000000000000000000000000..178341b670fa249fa50157d878ac2a66bd7f1843 |
--- /dev/null |
+++ b/fusl/src/math/atanf.c |
@@ -0,0 +1,94 @@ |
+/* origin: FreeBSD /usr/src/lib/msun/src/s_atanf.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 atanhi[] = { |
+ 4.6364760399e-01, /* atan(0.5)hi 0x3eed6338 */ |
+ 7.8539812565e-01, /* atan(1.0)hi 0x3f490fda */ |
+ 9.8279368877e-01, /* atan(1.5)hi 0x3f7b985e */ |
+ 1.5707962513e+00, /* atan(inf)hi 0x3fc90fda */ |
+}; |
+ |
+static const float atanlo[] = { |
+ 5.0121582440e-09, /* atan(0.5)lo 0x31ac3769 */ |
+ 3.7748947079e-08, /* atan(1.0)lo 0x33222168 */ |
+ 3.4473217170e-08, /* atan(1.5)lo 0x33140fb4 */ |
+ 7.5497894159e-08, /* atan(inf)lo 0x33a22168 */ |
+}; |
+ |
+static const float aT[] = { |
+ 3.3333328366e-01, |
+ -1.9999158382e-01, |
+ 1.4253635705e-01, |
+ -1.0648017377e-01, |
+ 6.1687607318e-02, |
+}; |
+ |
+float atanf(float x) |
+{ |
+ float_t w,s1,s2,z; |
+ uint32_t ix,sign; |
+ int id; |
+ |
+ GET_FLOAT_WORD(ix, x); |
+ sign = ix>>31; |
+ ix &= 0x7fffffff; |
+ if (ix >= 0x4c800000) { /* if |x| >= 2**26 */ |
+ if (isnan(x)) |
+ return x; |
+ z = atanhi[3] + 0x1p-120f; |
+ return sign ? -z : z; |
+ } |
+ if (ix < 0x3ee00000) { /* |x| < 0.4375 */ |
+ if (ix < 0x39800000) { /* |x| < 2**-12 */ |
+ if (ix < 0x00800000) |
+ /* raise underflow for subnormal x */ |
+ FORCE_EVAL(x*x); |
+ return x; |
+ } |
+ id = -1; |
+ } else { |
+ x = fabsf(x); |
+ if (ix < 0x3f980000) { /* |x| < 1.1875 */ |
+ if (ix < 0x3f300000) { /* 7/16 <= |x| < 11/16 */ |
+ id = 0; |
+ x = (2.0f*x - 1.0f)/(2.0f + x); |
+ } else { /* 11/16 <= |x| < 19/16 */ |
+ id = 1; |
+ x = (x - 1.0f)/(x + 1.0f); |
+ } |
+ } else { |
+ if (ix < 0x401c0000) { /* |x| < 2.4375 */ |
+ id = 2; |
+ x = (x - 1.5f)/(1.0f + 1.5f*x); |
+ } else { /* 2.4375 <= |x| < 2**26 */ |
+ id = 3; |
+ x = -1.0f/x; |
+ } |
+ } |
+ } |
+ /* end of argument reduction */ |
+ z = x*x; |
+ w = z*z; |
+ /* break sum from i=0 to 10 aT[i]z**(i+1) into odd and even poly */ |
+ s1 = z*(aT[0]+w*(aT[2]+w*aT[4])); |
+ s2 = w*(aT[1]+w*aT[3]); |
+ if (id < 0) |
+ return x - x*(s1+s2); |
+ z = atanhi[id] - ((x*(s1+s2) - atanlo[id]) - x); |
+ return sign ? -z : z; |
+} |