1This is a patched version of zlib, modified to use 2Pentium-Pro-optimized assembly code in the deflation algorithm. The 3files changed/added by this patch are: 4 5README.686 6match.S 7 8The speedup that this patch provides varies, depending on whether the 9compiler used to build the original version of zlib falls afoul of the 10PPro's speed traps. My own tests show a speedup of around 10-20% at 11the default compression level, and 20-30% using -9, against a version 12compiled using gcc 2.7.2.3. Your mileage may vary. 13 14Note that this code has been tailored for the PPro/PII in particular, 15and will not perform particuarly well on a Pentium. 16 17If you are using an assembler other than GNU as, you will have to 18translate match.S to use your assembler's syntax. (Have fun.) 19 20Brian Raiter 21breadbox@muppetlabs.com 22April, 1998 23 24 25Added for zlib 1.1.3: 26 27The patches come from 28http://www.muppetlabs.com/~breadbox/software/assembly.html 29 30To compile zlib with this asm file, copy match.S to the zlib directory 31then do: 32 33CFLAGS="-O3 -DASMV" ./configure 34make OBJA=match.o 35 36 37Update: 38 39I've been ignoring these assembly routines for years, believing that 40gcc's generated code had caught up with it sometime around gcc 2.95 41and the major rearchitecting of the Pentium 4. However, I recently 42learned that, despite what I believed, this code still has some life 43in it. On the Pentium 4 and AMD64 chips, it continues to run about 8% 44faster than the code produced by gcc 4.1. 45 46In acknowledgement of its continuing usefulness, I've altered the 47license to match that of the rest of zlib. Share and Enjoy! 48 49Brian Raiter 50breadbox@muppetlabs.com 51April, 2007 52