((function atan
   (signature float
     (parameters
       (declare (in) float x))
     ((return (call asin ((expression float *
			   (var_ref x)
			   (expression float rsq
			    (expression float +
			     (expression float *
			      (var_ref x)
			      (var_ref x))
			     (constant float (1.0))))))))))

   (signature vec2
     (parameters
       (declare (in) vec2 y_over_x))
     ((return (call asin ((expression vec2 *
			   (var_ref y_over_x)
			   (expression vec2 rsq
			    (expression vec2 +
			     (expression vec2 *
			      (var_ref y_over_x)
			      (var_ref y_over_x))
			     (constant float (1.0))))))))))

   (signature vec3
     (parameters
       (declare (in) vec3 y_over_x))
     ((return (call asin ((expression vec3 *
			   (var_ref y_over_x)
			   (expression vec3 rsq
			    (expression vec3 +
			     (expression vec3 *
			      (var_ref y_over_x)
			      (var_ref y_over_x))
			     (constant float (1.0))))))))))

   (signature vec4
     (parameters
       (declare (in) vec4 y_over_x))
     ((return (call asin ((expression vec4 *
			   (var_ref y_over_x)
			   (expression vec4 rsq
			    (expression vec4 +
			     (expression vec4 *
			      (var_ref y_over_x)
			      (var_ref y_over_x))
			     (constant float (1.0))))))))))

   (signature float
     (parameters
       (declare (in) float y)
       (declare (in) float x))
     ((declare () float r)
      (if (expression bool >
	   (expression float abs (var_ref x))
	   (constant float (.0001)))
       ((assign (constant bool (1))
	 (var_ref r) (call atan ((expression float /
				  (var_ref y)
				  (var_ref x)))))
	(if (expression bool <
	     (var_ref x)
	     (constant float (0.0)))
	 ((assign (constant bool (1))
	   (var_ref r)
	   (expression float +
	    (var_ref r)
	    (expression float *
	     (expression int sign (var_ref y))
	     (constant float (3.1415926))))))
	 ()))
       ())
      (return (var_ref r))))

   (signature vec2
     (parameters
       (declare (in) vec2 y)
       (declare (in) vec2 x))
     ((declare () vec2 r)
      (if (expression bool >
	   (expression vec2 abs (var_ref x))
	   (constant float (.0001)))
       ((assign (constant bool (1))
	 (var_ref r) (call atan ((expression vec2 /
				  (var_ref y)
				  (var_ref x)))))
	(if (expression bool <
	     (var_ref x)
	     (constant float (0.0)))
	 ((assign (constant bool (1))
	   (var_ref r)
	   (expression vec2 +
	    (var_ref r)
	    (expression vec2 *
	     (expression int sign (var_ref y))
	     (constant float (3.1415926))))))
	 ()))
       ())
      (return (var_ref r))))

   (signature vec3
     (parameters
       (declare (in) vec3 y)
       (declare (in) vec3 x))
     ((declare () vec3 r)
      (if (expression bool >
	   (expression vec3 abs (var_ref x))
	   (constant float (.0001)))
       ((assign (constant bool (1))
	 (var_ref r) (call atan ((expression vec3 /
				  (var_ref y)
				  (var_ref x)))))
	(if (expression bool <
	     (var_ref x)
	     (constant float (0.0)))
	 ((assign (constant bool (1))
	   (var_ref r)
	   (expression vec3 +
	    (var_ref r)
	    (expression vec3 *
	     (expression int sign (var_ref y))
	     (constant float (3.1415926))))))
	 ()))
       ())
      (return (var_ref r))))

   (signature vec4
     (parameters
       (declare (in) vec4 y)
       (declare (in) vec4 x))
     ((declare () vec4 r)
      (if (expression bool >
	   (expression vec4 abs (var_ref x))
	   (constant float (.0001)))
       ((assign (constant bool (1))
	 (var_ref r) (call atan ((expression vec4 /
				  (var_ref y)
				  (var_ref x)))))
	(if (expression bool <
	     (var_ref x)
	     (constant float (0.0)))
	 ((assign (constant bool (1))
	   (var_ref r)
	   (expression vec4 +
	    (var_ref r)
	    (expression vec4 *
	     (expression int sign (var_ref y))
	     (constant float (3.1415926))))))
	 ()))
       ())
      (return (var_ref r))))

))