System and method for decompressing data. A compressed data stream including contiguous variable length blocks is received, each block including multiple contiguous variable length data fields and a tag portion that includes multiple contiguous tag fields corresponding respectively to the data fields. Each tag field stores a tag value specifying a size of a respective field in the block. A current variable length block is stored. A single machine instruction of a processor is executed that analyzes the tag portion of the current block, and creates a control pattern, storing the control pattern in a first register of the processor. The control pattern is configured to unpack the variable length data fields of the current variable length block into corresponding uniform data fields. The contiguous variable length data fields of the current variable length block are decompressed using the control pattern, thereby decompressing the compressed data stream.