Compressing program binaries with reduced compression ratios. One or
several pre-processing acts are performed before performing compression using a
local sequential correlation oriented compression technology such as PPM, or one
of its variants or improvements. One pre-processing act splits the binaries into
several substreams that have high local sequential correlation. Such splitting
takes into consideration the correlation between common fields in different instructions
as well as the correlation between different fields in the same instruction. Another
pre-processing reschedules binary instructions to improve the degree of local sequential
correlation without affecting dependencies between instructions. Yet another pre-processing
act replaces common operation codes in the instruction with a symbols from a second
alphabet, thereby distinguishing between operation codes that have a particular
value, and other portions of the instruction that just happen to have the same
value. Local sequential correlation compression such as PPM is then performed.
