HTML5 Canvas efficiency -

does html5 canvas waste memory , cpu render pixels off window?

suppose have following 3 images want render onto 100 100 canvas:

+---------+-------+--------+-------+-------+--------------------+ |  image  | width | height |   x   |   y   |   remark           | +---------+-------+--------+-------+-------+--------------------+ |  1.svg  | 50    | 80     | 10    | 10    | fits in            | +---------+-------+--------+-------+-------+--------------------+ |  2.svg  | 200   | 180    | -30   | 10    | partially fits     | +---------+-------+--------+-------+-------+--------------------+ |  3.svg  | 300   | 400    | 130   | 200   | totally off canvas | +---------+-------+--------+-------+-------+--------------------+ 

if draw 3 images onto canvas, native code intelligent enough not waste resources drawing parts of 2.svg , whole of 3.svg, or our responsibility clip/skip these in tile engine?