I found there is a new group of routines about sparse matrix in version 11.3. It is said in manual：SpMV 2 API divides into two stages, analysis and execution.
Now，I have some questions about analysis routines:
1. Is it necessary before run execution routines?
2. How to use them correctly? I found that only the mkl_sparse_optimize routine run before executions in example sparse_csr.c. And in another example solver_cg.c, there are some mkl_sparse_set_xx_hint routines before the mkl_sparse_optimize(). I can not get any detail message about this in manual.
3. The matrix_descr is defined explicit in user code. What happens if it is not defined, or the definition of matrix_descr attribute is error?
mkl_sparse_set_xx_hint allow function mkl_optimize to prepare data exactly for required functionality. If you have not call mkl optimize or call execute function with correspond hint set performance of execution function can be less than otherwise.