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Diffstat (limited to 'zlib/contrib/asm586/README.586')
-rw-r--r-- | zlib/contrib/asm586/README.586 | 43 |
1 files changed, 0 insertions, 43 deletions
diff --git a/zlib/contrib/asm586/README.586 b/zlib/contrib/asm586/README.586 deleted file mode 100644 index 6bb78f320..000000000 --- a/zlib/contrib/asm586/README.586 +++ /dev/null @@ -1,43 +0,0 @@ -This is a patched version of zlib modified to use -Pentium-optimized assembly code in the deflation algorithm. The files -changed/added by this patch are: - -README.586 -match.S - -The effectiveness of these modifications is a bit marginal, as the the -program's bottleneck seems to be mostly L1-cache contention, for which -there is no real way to work around without rewriting the basic -algorithm. The speedup on average is around 5-10% (which is generally -less than the amount of variance between subsequent executions). -However, when used at level 9 compression, the cache contention can -drop enough for the assembly version to achieve 10-20% speedup (and -sometimes more, depending on the amount of overall redundancy in the -files). Even here, though, cache contention can still be the limiting -factor, depending on the nature of the program using the zlib library. -This may also mean that better improvements will be seen on a Pentium -with MMX, which suffers much less from L1-cache contention, but I have -not yet verified this. - -Note that this code has been tailored for the Pentium in particular, -and will not perform well on the Pentium Pro (due to the use of a -partial register in the inner loop). - -If you are using an assembler other than GNU as, you will have to -translate match.S to use your assembler's syntax. (Have fun.) - -Brian Raiter -breadbox@muppetlabs.com -April, 1998 - - -Added for zlib 1.1.3: - -The patches come from -http://www.muppetlabs.com/~breadbox/software/assembly.html - -To compile zlib with this asm file, copy match.S to the zlib directory -then do: - -CFLAGS="-O3 -DASMV" ./configure -make OBJA=match.o |