How to get 64bit dll for python in windows by Makefile.win

[CharlesMei]

I want to use python interface for 64bit python in windows, but the liblinear.dll in the /windows directory seems to be 32bit one. And i can not generate 64bit dll by "nmake -f Makefile.win clean all" , this just generate exe file in /windows directory. So how can i do that?

[infwinston]

You should try "nmake -f Makefile.win lib" to generate .dll file.

[CharlesMei]

@infwinston Thank you! It works! But when i use "from liblinearutil import *", it throws "AttributeError: function 'find_parameter_C' not found".When i comment "fillprototype(liblinear.find_parameter_C, None, [POINTER(problem), POINTER(parameter), c_int, c_double, c_double, POINTER(c_double), POINTER(c_double)])" in the liblinear.py， it throws no errors. But what should i do if i want to use find_parameter_C

[infwinston]

Hi, @CharlesMei
I find the problem is the authors forget to add somethings in linear.def,
Here is one of the solutions for now,
in linear.def, add a line of code:

"find_parameter_C @20"

then re-compile the dll file, you may use the function successfully.
Hope this helps.

[infwinston]

BTW, I think the dll file in liblinear-2.01 is already 64-bit version, why do you need to re-generate the dll?

[CharlesMei]

Hi, @infwinston Thank you! It works well! You're right, it's already 64-bit version. When i use the original dll in liblinear-2.01, it throws errors when i use "from liblinearutil import *", and it is because of the find_parameter_C problem. When i use libsvm-3.20, it needs to re-generate the dll for 64bit to solve the import error, so i thought it may need to do the same in liblinear-2.01. I'm sorry for that.

[simsong]

This issue was moved to angleto#19

[se210]

In case it helps anybody, I was able to compile a 64-bit version DLL for an older release of liblinear which has 32-bit executable included.

First, activate the Visual C++ toolset in 64-bit mode from by running
vcvarsall amd64
then run
nmake -f Makefile.win lib
as stated above.