A graphics processing unit (GPU) that performs rendering in units of tiles includes a coefficient generator that produces an interpolation coefficient based on coordinates of vertices of a primitive included in a first tile and a second tile; an interpolator that produces barycentric coordinates in respective pixels for the first tile of the primitive and pixel values in the first tile corresponding to the primitive, based on the interpolation coefficient, and a storage configured to store the interpolation coefficient. The GPU produces barycentric coordinates in and pixel values of respective pixels for a second tile of the primitive, based on the interpolation coefficient stored in the storage.