How do I define in Cython an external C ++ function that has input parameters as enumerations? MKL

So while trying to wrap this in Cython from MKL and dig into mkl_cblas.h

, I can see that these are enums:

typedef enum {CblasRowMajor=101, CblasColMajor=102} CBLAS_ORDER;


typedef enum {CblasNoTrans=111, CblasTrans=112, CblasConjTrans=113} CBLAS_TRANSPOSE;

And here is the function declaration:

void cblas_dgemm(const  CBLAS_LAYOUT Layout, const  CBLAS_TRANSPOSE TransA,
                 const  CBLAS_TRANSPOSE TransB, const MKL_INT M, const MKL_INT N,
                 const MKL_INT K, const double alpha, const double *A,
                 const MKL_INT lda, const double *B, const MKL_INT ldb,
                 const double beta, double *C, const MKL_INT ldc);

      

        
        
        
      

    

Cython documentation is missing in this area as it seems like it suggests converting everything to int

, but then the MKL function complains that I didn't pass it the correct type ( enums

CBLAS_LAYOUT

and CBLAS_TRANSPOSE

not a type int

).

What is the correct way to identify them from Keaton? I.e:.

cimport cython

cdef extern from "mkl.h" nogil:
      ctypedef enum CBLAS_LAYOUT:
          CblasRowMajor
          CblasColMajor
      ctypedef enum CBLAS_TRANSPOSE:
          CblasNoTrans
          CblasTrans
          CblasConjTrans
      void dgemm "cblas_dgemm"(CBLAS_LAYOUT Layout,
                               CBLAS_TRANSPOSE TransA,
                               CBLAS_TRANSPOSE TransB,
                               int M,
                               int N,
                               int K,
                               double alpha,
                               double *A,
                               int lda,
                               double *B,
                               int ldb,
                               double beta,
                               double *C,
                               int ldc                              
                              )

      

        
        
        
      

    

The above compiles without error. But I got no results in C

(until I changed it to CblasColMajor

by calling dgemm

after I posted this). So I wonder if anyone can confirm if this is correct above.

I profiled above and SciPy

inline version Using the cython_blas Scipy interface from Cython not working on Mx1 1xN vectors and they are about the same (mine SciPy

is related to MKL) so I guess this is correct, but if there is a better / quicker way to do this please , post offers. However, I'll leave this posted for others as it doesn't look well documented in Cython.