update changelog; add more copyright notices

Author: japaric

CHANGELOG.md

@@ -7,14 +7,29 @@ This project adheres to [Semantic Versioning](http://semver.org/).
 
 ### Added
 
+- acosf
+- asin
+- asinf
+- atan
+- atan2
 - atan2f
+- atanf
 - cos
+- cosf
+- cosh
 - coshf
+- exp2
+- expm1
+- expm1f
+- expo2
 - fmaf
+- pow
 - sin
+- sinf
 - sinh
 - sinhf
 - tan
+- tanf
 - tanh
 - tanhf
 

src/math/atan.rs

@@ -1,3 +1,14 @@
+/* origin: FreeBSD /usr/src/lib/msun/src/s_atan.c */
+/*
+ * ====================================================
+ * 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.
+ * ====================================================
+ */
 /* atan(x)
  * Method
  *   1. Reduce x to positive by atan(x) = -atan(-x).

src/math/atan2.rs

@@ -1,3 +1,42 @@
+/* origin: FreeBSD /usr/src/lib/msun/src/e_atan2.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.
+ * ====================================================
+ *
+ */
+/* atan2(y,x)
+ * Method :
+ *      1. Reduce y to positive by atan2(y,x)=-atan2(-y,x).
+ *      2. Reduce x to positive by (if x and y are unexceptional):
+ *              ARG (x+iy) = arctan(y/x)           ... if x > 0,
+ *              ARG (x+iy) = pi - arctan[y/(-x)]   ... if x < 0,
+ *
+ * Special cases:
+ *
+ *      ATAN2((anything), NaN ) is NaN;
+ *      ATAN2(NAN , (anything) ) is NaN;
+ *      ATAN2(+-0, +(anything but NaN)) is +-0  ;
+ *      ATAN2(+-0, -(anything but NaN)) is +-pi ;
+ *      ATAN2(+-(anything but 0 and NaN), 0) is +-pi/2;
+ *      ATAN2(+-(anything but INF and NaN), +INF) is +-0 ;
+ *      ATAN2(+-(anything but INF and NaN), -INF) is +-pi;
+ *      ATAN2(+-INF,+INF ) is +-pi/4 ;
+ *      ATAN2(+-INF,-INF ) is +-3pi/4;
+ *      ATAN2(+-INF, (anything but,0,NaN, and INF)) is +-pi/2;
+ *
+ * Constants:
+ * The hexadecimal values are the intended ones for the following
+ * constants. The decimal values may be used, provided that the
+ * compiler will convert from decimal to binary accurately enough
+ * to produce the hexadecimal values shown.
+ */
+
 use super::atan;
 use super::fabs;
 

src/math/atan2f.rs

@@ -1,3 +1,18 @@
+/* origin: FreeBSD /usr/src/lib/msun/src/e_atan2f.c */
+/*
+ * Conversion to float by Ian Lance Taylor, Cygnus Support, [email protected].
+ */
+/*
+ * ====================================================
+ * 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.
+ * ====================================================
+ */
+
 use super::atanf;
 use super::fabsf;