Simulink Coder with user-defined functions: data store read block vs global declaration

Hello, I'm using Simulink Coder to generate c-code from my Simulink model. I'm making use of user-defined m-functions and data stores. To read/write to those data-stores in m-functions I've two options: -"data-store read/write" blocks, passing then data as input/output to function; -declare the data store as "global" inside the m-function and setting its scope as "data-store memory";

Which are pros and cons of two approaches when looking at the generated c-code? Thanks in advance BR

Dave