  Stencil computation is an important class of scientific applications that can
be efficiently executed by graphics processing units (GPUs). Out-of-core
approach helps run large scale stencil codes that process data with sizes
larger than the limited capacity of GPU memory. However, the performance of the
GPU-based out-of-core stencil computation is always limited by the data
transfer between the CPU and GPU. Many optimizations have been explored to
reduce such data transfer, but the study on the use of on-the-fly compression
techniques is far from sufficient. In this study, we propose a method that
accelerates the GPU-based out-of-core stencil computation with on-the-fly
compression. We introduce a novel data compression approach that solves the
data dependency between two contiguous decomposed data blocks. We also modify a
widely used GPU-based compression library to support pipelining that overlaps
CPU/GPU data transfer with GPU computation. Experimental results show that the
proposed method achieved a speedup of 1.2x compared the method without
compression. Moreover, although the precision loss involved by compression
increased with the number of time steps, the precision loss was trivial up to
4,320 time steps, demonstrating the usefulness of the proposed method.
