The 32-bit build is now for i686 or newer because the
prebuilt MinGW-w64 toolchains include i686 code in the
executables even if one uses -march=i486.
The build script builds 32-bit SSE2 enabled version too.
Run-time detection of SSE2 support would be nice (on any OS)
but it's not implemented in XZ Utils yet.
Now liblzma only uses "mythread" functions and types
which are defined in mythread.h matching the desired
threading method.
Before Windows Vista, there is no direct equivalent to
pthread condition variables. Since this package doesn't
use pthread_cond_broadcast(), pre-Vista threading can
still be kept quite simple. The pre-Vista code doesn't
use anything that wasn't already available in Windows 95,
so the binaries should run even on Windows 95 if someone
happens to care.
The example programs by Daniel Mealha Cabrita were included
in the git repository, but I had forgot to add them to
Makefile.am. Thus, they didn't get included in the source
package at all by "make dist".
This is simply for licensing reasons. The 64-bit version
will be built with MinGW-w64 anyway (at least for now),
so using it also for 32-bit build allows using the same
copyright notice about the MinGW-w64/w32 runtime.
Note that using MinGW would require a copyright notice too,
because its runtime is not in the public domain either even
though MinGW's home page claims that it is public domain.
See <http://marc.info/?l=mingw-users&m=126489506214078>.
Antoine Cœur