Method and device for compressing data, and method and device for decompressing data

A method for compressing pre-compressed data used in a reconfigurable processor, where the pre-compressed data includes a number of data blocks, obtains a current data block, calculates a current checking code of the current data block, and compares the current checking code with an immediately-previous checking code. A tag of the current data block is marked as a first tag if the current checking code and the immediately-previous checking code are different, and is marked as a second tag if the current checking code and the immediately-previous checking code are the same. Only data blocks whose tags are the first tags are saved. A related device for compressing data, and a method and a device for decompressing data are also provided.