It looks like some work has been done to make pthread-win32 work with x64, but there are no build instructions. I have tried simly building with the Visual Studio x64 Cross Tools Command Prompt, but when I try to link to the lib from an x64 application, it can't see any of the function exports. It seems like it is still compiling the lib as x86 or something.
I've even tried adding /MACHINE to the makefile in the appropriate places, but it doesn't help. Has anyone gotten this to work?
Until it's officially released, it looks like you have to check out the CVS head to get version 2.9 of the library. Version 2.9 has all the x64 patches, but you will still have problems if you try to compile the static library from the command line.
The only workaround I know of is to use the DLLs instead of statically linking the LIB.