pnggccrd.c and pngvcrd.c version "1.0.9pre3" of 18 September 2000

These "final" versions of pnggccrd.c and pngvcrd.c, the MMX assembler
routines for the gcc/gas and MSVC compilers, are now functionally
equivalent--and one last(?) MMX bug in the 16-bit grayscale case has
been fixed in both versions.  Unpack libpng 1.0.8, delete or rename
the stock versions of the two files, put these versions in their place,
and use one of the MMX makefiles (such as the included makefile.gcmmx
for gcc/gas) to compile libpng.

Note that this code only speeds up the *decoding* of PNG images.  Also,
not every possible code path has been tested, nor has every possible
version of gcc and binutils or of MSVC (versions before 5.0 may not grok
MMX).  Finally, gcc's own CPU-specific optimizations may provide almost
as much benefit as some of the MMX routines, at least for newer versions
of gcc and some types of images.  The MMX code should be very stable,
but as always, do your own testing, and caveat "emptor." :-)

See http://www.libpng.org/pub/png/libpng.html for updates.

Greg Roelofs
newt@pobox.com
