Code generation with Lapacke Class doesn't generate Laplack function

Hello,

I try to create C/C++ code with a Lapack function. I followed this instruction to setup my main-function like:

function i = main() 

    rng(4);
    A = rand(2600,2600);

    tic
    s = svd(A);
    toc

    tic
    [X_mat,lambda] = eig(A); 
    toc

    fprintf('%f : svd\n', s(1));
    fprintf('%f : eigX\n', X_mat(1));
	fprintf('%f : eigL\n', lambda(1));

    i = int32(0); %return 0

end

Then creating the respective Class file:

classdef LapackClass < coder.LAPACKCallback
    methods (Static)
        function hn = getHeaderFilename()
            hn = 'lapacke.h';
        end
        function updateBuildInfo(buildInfo, buildctx)
            buildInfo.addIncludePaths(fullfile(pwd,'include'));
            libName = 'liblapack';
            libPath = fullfile(pwd,'lib');
            [~,linkLibExt] = buildctx.getStdLibInfo();
            buildInfo.addLinkObjects([libName linkLibExt], libPath, '', true, true);
            buildInfo.addDefines('HAVE_LAPACK_CONFIG_H');
            buildInfo.addDefines('LAPACK_COMPLEX_STRUCTURE');
            buildInfo.addDefines('LAPACK_ILP64'); 
        end
    end
end

Then putting the header files und lib files in respective folders of the projekt folder like:

and finally setting the Custom callback in the coders advanced settings like:

I figured this is the equivament of the 3) Specify the LAPACK callback class useMyLAPACK in the instructions,

I then hit Generate, but in the resulting main.cpp, there is no different function call to the Lapack lib and in the make-file I couldn't find any trace of that either.

...  
  double s[2600];
  state[624] = 624U;
  coder::b_rand(A);
  coder::tic();
  coder::svd(A, s);
  coder::toc();
...

Can someone hint me to what I need to change to make Matlab generate the code with Lapack call please?

[Ryan Livingston]

The steps you've followed should produce LAPACK calls. Can you check the contents of the coder::svd and coder::eig functions to see if there are references to any LAPACKE_*functions? There should also be a reference to lapacke.h in those files. Note there generally will not be a change in main.cpp. The changes will be in the implementations of svd and eig.

I tried the code you showed and see the following

svd.cpp

// Include Files
#include "svd.h"
#include "rt_nonfinite.h"
#include "lapacke.h"
#include <algorithm>

// Function Definitions
//
// Arguments    : const double A[6760000]
//                double U[2600]
// Return Type  : void
//
namespace coder {
void svd(const double A[6760000], double U[2600])
{
  static double b_A[6760000];
  lapack_int info_t;
  double superb[2599];
  std::copy(&A[0], &A[6760000], &b_A[0]);
  info_t = LAPACKE_dgesvd(LAPACK_COL_MAJOR, 'N', 'N', (lapack_int)2600,
                          (lapack_int)2600, &b_A[0], (lapack_int)2600, &U[0],
                          nullptr, (lapack_int)1, nullptr, (lapack_int)1,
                          &superb[0]);

xgeev.cpp

// Include Files
#include "xgeev.h"
#include "rt_nonfinite.h"
#include "lapacke.h"
#include <algorithm>

// Function Definitions
//
// Arguments    : const double A[6760000]
//                int *info
//                creal_T W[2600]
//                creal_T VR[6760000]
// Return Type  : void
//
namespace coder {
namespace internal {
namespace lapack {
void xgeev(const double A[6760000], int *info, creal_T W[2600],
           creal_T VR[6760000])
{
  static double b_A[6760000];
  static double vright[6760000];
  lapack_int ihi_t;
  lapack_int ilo_t;
  lapack_int info_t;
  double scale[2600];
  double wimag[2600];
  double wreal[2600];
  double abnrm;
  double rconde;
  double rcondv;
  double vleft;
  std::copy(&A[0], &A[6760000], &b_A[0]);
  info_t = LAPACKE_dgeevx(
      LAPACK_COL_MAJOR, 'B', 'N', 'V', 'N', (lapack_int)2600, &b_A[0],
      (lapack_int)2600, &wreal[0], &wimag[0], &vleft, (lapack_int)1, &vright[0],
      (lapack_int)2600, &ilo_t, &ihi_t, &scale[0], &abnrm, &rconde, &rcondv);

Some debugging steps:

• Use the MATLAB find in files tool to do a case insensitive search for "lapacke". That should show some calls like what I pasted above.
• Generate code with and without specifying LapackClass and compare the codegen folders using the MATLAB comparison tool. Specifically pay attention to main_rtw.mk, svd.cpp, eig.cpp, xgeev.cpp to see if any changes show up. You should see your library in main_rtw.mk, an include of lapacke.h in the C++ files, and references to LAPACKE_*functions.
• If that doesn't show anything, put a breakpoint in your updateBuildInfo in LapackClass.m in the MATLAB editor and run codegen / click the generate button. If this breakpoint triggers, your class is being used.
• If the breakpoint isn't being hit, then this sounds like a possible issue in MATLAB Coder. We'd love if you could reach out to MathWorks technical support to share reproduction steps so we can investigate further.

[Andreas Scholz]

Thanks for your answer and sorry for my delayed response. I did do a Grep on the folder, but in my case, there was no usage of lapack/e in any file. As it turns out, we can't use the approach anyway, because we require to hand a parameter file to the main function at the end (in the real project), which defines required array sizes, but coder doesn't accept this; it seems to want to know the sizes during generation time, preventing the possibility to calculate different situations than the initial one. So we are no longer following this approach atm.