The tremendous sbrage space required for a useful data base of traces has driven a search for trace compaction techniques. In this paper we present an information-lossless trace compnssion scheme that can reduce both storage space and access time by an order of magnitude or more, compared to ASCII-format traces, without discarding either references or inter-reference timing from the original trace.This technique has been selected as the standard trace format for an extensive new trace data base that will be made accessible to the intemational research and teaching community.

The tremendous storage space required for a useful data base of program traces has prompted a search for trace reduction techniques. In this paper we discuss a range of information-lossless address and instruction trace compression schemes that can reduce both storage space and access time by an order of magnitude or more, without discarding either references or inter-reference timing information from the original trace. The PDATS family of trace compression techniques achieves trace coding densities of about six references per byte. This family of techniques is now in use as the standard in the NMSU TraceBase, an extensive trace archive that has been established for use by the international research and teaching community.