1. A computer for executing instructions, comprising: an instruction decoder unit configured to decode a macro instruction into at least one micro-operation with a set of data fields, wherein at least one data field in the set of data fields is in a compressed form, the instruction decoder unit including: storage logic configured to store the at least one micro-operation with the at least one compressed-form data field; extraction logic configured to extract the at least one compressed-form data field into an uncompressed-form data field; and send the at least one micro-operation with the extracted uncompressed-form data field to an execution unit for execution; and an execution unit configured to execute the at least one micro-operation.