GPU Acceleration of Newton´s Method for Large Systems of Polynomial Equations in Double Double and Quad Double Arithmetic

In order to compensate for the higher cost of double double and quad double arithmetic when solving large polynomial systems, we investigate the application of the NVIDIA Tesla K20C graphics processing unit (GPU). The focus on this paper is on Newton´s method, which requires the evaluation of the polynomials, their derivatives, and the solution of a linear system to compute the update to the current approximation for the solution. The reverse mode of algorithmic differentiation for a product of variables is rewritten in a binary tree fashion so all threads in a block can collaborate in the computation. For double arithmetic, the evaluation and differentiation problem is memory bound, whereas for complex quad double arithmetic the problem is compute bound. With acceleration we can double the dimension and get results that are twice as accurate in about the same time.