Does Google Cloud Spanner support compression?

Our dataset has rows that are highly compressed relative to adjacent rows. As far as I understand, Bigtable supports automatic compression (via compressing the SSTable block). It will make a huge difference to us if Spanner can or will support such compression at the database level. We project this to make a 3-5-fold difference in our cost structure. While we might think about trying to do this at the application level, it's not very fun ...