ross@spam.ua.oz.au (Ross Williams) (06/16/91)
If one of my LZRW* data compression algorithms finds that it has expanded the data instead of contracting it, it scraps the compression operation and resorts to a copy operation instead. This allows a fixed upper bound of a few bytes to be placed on the potential expansion. Compressor heads who are using the 68000 version of LZRW1 or who want a 68000 fast memory block copy (using unrolled loops and so forth) may be interested in my fast block memory routine written in 68000 machine code. It will pop up in the following ftp archive in the next day or so (I do not have the power to put stuff in our archive directly - I have to ask). Machine: sirius.itd.adelaide.edu.au IP=129.127.40.3 Directory: pub/misc File: fast_copy.68000 Enjoy, Ross Williams ross@spam.ua.oz.au
jms@tardis.Tymnet.COM (Joe Smith) (06/18/91)
In article <845@spam.ua.oz> ross@spam.ua.oz.au (Ross Williams) writes: >Compressor heads who are using the 68000 version of LZRW1 or who want >a 68000 fast memory block copy (using unrolled loops and so forth) may >be interested in my fast block memory routine written in 68000 machine code. Isn't this called "re-inventing the wheel"? How is your code better than the other 97 implementations of "fast block copy"? It's been about 10 years since the idea of using MOVEM.L in an unrolled loop was invented; have you compared your implementation to the standard routines? -- Joe Smith (408)922-6220 | SMTP: jms@tardis.tymnet.com or jms@gemini.tymnet.com BT Tymnet Tech Services | UUCP: ...!{ames,pyramid}!oliveb!tymix!tardis!jms PO Box 49019, MS-C51 | BIX: smithjoe | CA license plate: "POPJ P," (PDP-10) San Jose, CA 95161-9019 | humorous disclaimer: "My Amiga 3000 speaks for me."