mm-test

$ cat mm_int_blas.c
#include <stdio.h>
#include <stdlib.h>
#include <time.h>
#include <cblas.h>
#define N 1200
void fill_matrices(double first[][N], double second[][N], double result[][N])
{
    srand(time(NULL)); // randomize seed
    for (int i = 0; i < N; i++){
        for (int j = 0; j < N; j++){
            first[i][j] = rand() % 10;
            second[i][j] = rand() % 10;
            result[i][j] = 0;
        }
    }
}
int main()
{
    static double first[N][N], second[N][N], result[N][N];
    fill_matrices(first, second, result);

    cblas_dgemm(CblasRowMajor, CblasNoTrans, CblasNoTrans, N,N,N, 1.0, first, N, second, N, 0.0, result, N);

    return 0;
}



$ gcc -O3  -c mm_int_blas.c -o mm_int_blas.o
mm_int_blas.c: In function ‘main’:
mm_int_blas.c:22:72: warning: passing argument 8 of ‘cblas_dgemm’ from incompatible pointer type [-Wincompatible-pointer-types]
   22 |     cblas_dgemm(CblasRowMajor, CblasNoTrans, CblasNoTrans, N,N,N, 1.0, first, N, second, N, 0.0, result, N);
      |                                                                        ^~~~~
      |                                                                        |
      |                                                                        double (*)[1200]
In file included from mm_int_blas.c:4:
/usr/include/x86_64-linux-gnu/cblas.h:270:56: note: expected ‘const double *’ but argument is of type ‘double (*)[1200]’
  270 |    OPENBLAS_CONST double alpha, OPENBLAS_CONST double *A, OPENBLAS_CONST blasint lda, OPENBLAS_CONST double *B, OPENBLAS_CONST blasint ldb, OPENBLAS_CONST double beta, double *C, OPENBLAS_CONST blasint ldc);
      |                                                        ^
mm_int_blas.c:22:82: warning: passing argument 10 of ‘cblas_dgemm’ from incompatible pointer type [-Wincompatible-pointer-types]
   22 |     cblas_dgemm(CblasRowMajor, CblasNoTrans, CblasNoTrans, N,N,N, 1.0, first, N, second, N, 0.0, result, N);
      |                                                                                  ^~~~~~
      |                                                                                  |
      |                                                                                  double (*)[1200]
In file included from mm_int_blas.c:4:
/usr/include/x86_64-linux-gnu/cblas.h:270:110: note: expected ‘const double *’ but argument is of type ‘double (*)[1200]’
  270 |    OPENBLAS_CONST double alpha, OPENBLAS_CONST double *A, OPENBLAS_CONST blasint lda, OPENBLAS_CONST double *B, OPENBLAS_CONST blasint ldb, OPENBLAS_CONST double beta, double *C, OPENBLAS_CONST blasint ldc);
      |                                                                                                              ^
mm_int_blas.c:22:98: warning: passing argument 13 of ‘cblas_dgemm’ from incompatible pointer type [-Wincompatible-pointer-types]
   22 |     cblas_dgemm(CblasRowMajor, CblasNoTrans, CblasNoTrans, N,N,N, 1.0, first, N, second, N, 0.0, result, N);
      |                                                                                                  ^~~~~~
      |                                                                                                  |
      |                                                                                                  double (*)[1200]
In file included from mm_int_blas.c:4:
/usr/include/x86_64-linux-gnu/cblas.h:270:177: note: expected ‘double *’ but argument is of type ‘double (*)[1200]’
  270 | ST double alpha, OPENBLAS_CONST double *A, OPENBLAS_CONST blasint lda, OPENBLAS_CONST double *B, OPENBLAS_CONST blasint ldb, OPENBLAS_CONST double beta, double *C, OPENBLAS_CONST blasint ldc);
      |                                                                                                                                                          ~~~~~~~~^