added some fct documentation that can be implemented when we do a c version of an op.

doc/extending/cop.txt

@@ -39,16 +39,30 @@ There are less methods to define for an Op than for a Type:
 
       *Default:* The default behavior is to do nothing.
 
-    .. method:: c_compile_args()
-    .. method:: c_no_compile_args()
     .. method:: c_headers()
+    .. method:: c_header_dirs()
     .. method:: c_libraries()
+    .. method:: c_lib_dirs()
+
+      Allows you to specify headers, libraries, and their directories,
+
+    .. method:: c_compile_args()
+    .. method:: c_no_compile_args()
+
+      Allows you to specify special g++ arguments to add/exclude
+
     .. method:: c_support_code()
 
-      Allows you to specify headers, libraries,
-      special g++ arguments to add/exclude or
-      helper functions/structs that the type needs. See :ref:`op`.
+      Allows you to specify helper functions/structs that the type needs. See :ref:`op`.
+
+    .. method:: infer_shape(node, (i0_shapes,i1_shapes,...))
 
+      Allow optimization to lift the Shape op over this op. 
+      Example of why this is good is that we compute an op only to take its shape,
+      we will be able to have the shape without its computation.
+      must return a tuple with one tuple with the shape of each output.
+      Example of matrix-matrix product input_shapes will have as input
+      (node, (x0,x1), (y0,y1)) and should return ((x0, y1).
 
 The ``name`` argument is currently given an invalid value, so steer
 away from it. As was the case with Type, ``sub['fail']`` provides