how to link mex?

hi,

my code is:

function build_cropRectanglesMex( cudaRoot )
%build_cropRectanglesMex builds package cropRectanglesMex
%
% INPUT:
%   cudaRoot - path to the CUDA installation

% Anton Osokin, [e-mail], May 2015

if ~exist('cudaRoot', 'var')
    cudaRoot = 'C:\Program Files\NVIDIA GPU Computing Toolkit\CUDA\v8.0\' ;
end
nvccPath = fullfile(cudaRoot, 'bin', 'nvcc.exe')
if ~exist(nvccPath, 'file')
    error('NVCC compiler was not found!');
end

root = fileparts( mfilename('fullpath') );

% compiling
compileCmd = [ '"', nvccPath, '"', ...
        ' -c ', fullfile(root,'cropRectanglesMex.cu'), ... 
        ' -I"', fullfile( matlabroot, 'extern', 'include'), '"', ...
        ' -I"', fullfile( matlabroot, 'toolbox', 'distcomp', 'gpu', 'extern', 'include'), '"', ...
        ' -I"', fullfile( cudaRoot, 'include'), '"', ...        
        ' -DNDEBUG -DENABLE_GPU', ...
        ' -Xcompiler', ' -fPIC', ...
        ' -o "', fullfile(root,'cropRectanglesMex.o'), '"'];
system( compileCmd );build_cropRectanglesMex

% linking
mopts = {'-outdir', root, ...
         '-output', 'cropRectanglesMex', ...
         ['-L', fullfile(cudaRoot, 'lib','x64')], ...
         'cudart.lib', '-nppi', '-nppc', 'mwgpu', ...
         '-largeArrayDims', ...
         fullfile(root,'cropRectanglesMex.o') };
mex(mopts{:}) ;

delete( fullfile(root,'cropRectanglesMex.o') );

I get this error:

Error using mex
Unknown file extension ''.

Error in build_cropRectanglesMex (line 37)
mex(mopts{:}) ;

I believe the code is for linking in Linux. How can I do an equivalent linking for Windows?

[Walter Roberson]

Is it possible that 'mwgpu' should be '-mwgpu' ?

[Joss Knight]

Try adding -v to the list of mopts and run again. I don't really see how -nppi and -nppc can be valid options to mex, those are libraries and will need a -l in front to be linked.

Also, all this is very old school. You should be using mexcuda, which would save you most of this include file and linking bother.

[Kate]

I tried adding -v as follows:

mopts = {'-outdir', root, ...
         '-output', 'cropRectanglesMex', ...
         ['-L', fullfile(cudaRoot, 'lib','x64')], ...
         'cudart.lib', '-nppi', '-nppc', '-mwgpu', ...
         '-largeArrayDims', ...
          '-v', ...
         fullfile(root,'cropRectanglesMex.o') };
mex(mopts{:}) ;
delete( fullfile(root,'cropRectanglesMex.o') );

But then I get this error:

Error using mex
Unknown MEX argument '-mwgpu'.

Error in build_cropRectanglesMex2 (line 33)
mex(mopts{:}) ;

I tried mexcuda directly on the .cu file, but got an error as well:

>> mexcuda cropRectanglesMex.cu
Building with 'NVIDIA CUDA Compiler'.
Error using mex
   Creating library cropRectanglesMex.lib and object cropRectanglesMex.exp
cropRectanglesMex.obj : error LNK2019: unresolved external symbol nppiResizeSqrPixel_32f_P3R referenced in
function mexFunction
cropRectanglesMex.mexw64 : fatal error LNK1120: 1 unresolved externals

Error in mexcuda (line 157)
    [varargout{1:nargout}] = mex(mexArguments{:});

The code package is here, any help appreciated: github_code

[Joss Knight]

Using mexcuda you don't need to try to link mwgpu because that is done for you. And libraries are linked using the -l option; so you need -lnppi not -nppi.

[Hannah]

Kate, did you ever figure out the LNK2019 error when compiling with mexcuda? I am having the same issue.

Answer 1

[li zhaoliang]

ref this build_cropRectanglesMex in win32 is OK