[DSYRK](https://software.intel.com/en-us/mkl-developer-reference-fortran-syrk) performs a rank k update, computing along the triangle
[DSYRK](https://software.intel.com/en-us/mkl-developer-reference-fortran-syrk)or (DTRMM)[https://software.intel.com/en-us/mkl-developer-reference-fortran-trmm] performs a rank k update, computing along the triangle