warning in cub/device/dispatch/dispatch_spmv_orig.cuh

[seunghwak]

Related to: https://github.com/NVlabs/cub/issues/55

in cub/device/dispatch/dispatch_spmv_orig.cuh line 666 - 674

            dim3 spmv_grid_size(
                CUB_MIN(num_merge_tiles, max_dim_x),
                (num_merge_tiles + max_dim_x - 1) / max_dim_x,
                1);

            dim3 segment_fixup_grid_size(
                CUB_MIN(num_segment_fixup_tiles, max_dim_x),
                (num_segment_fixup_tiles + max_dim_x - 1) / max_dim_x,
1);

This generates the following warning as num_merge_tiles and num_segment_fixup_tiles are unsigned int and max_dim_x is int. This may be harmless but better be fixed...

/home/seunghwak/RAPIDS/cugraph/cpp/build/gunrock/externals/cub/cub/device/dispatch/dispatch_spmv_orig.cuh:666:32: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
             dim3 spmv_grid_size(
                     ~~~~~~~~~~~^                 
/home/seunghwak/RAPIDS/cugraph/cpp/build/gunrock/externals/cub/cub/device/dispatch/dispatch_spmv_orig.cuh:671:41: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
             dim3 segment_fixup_grid_size(
                              ~~~~~~~~~~~^