The attached test case defines and uses a global array and a function local static array. Build it ...

% tiarmclang -S file.c

Inspect the assembly to see these lines for the definition of the static array ...

        .section        .data.fxn.static_array,"aw",%progbits
        .p2align        2
fxn.static_array:
        .zero   400

Compare that to the definition of the global array ...

        .comm   global_array,400,4

It's in the common section, which eventually becomes .bss.

The 400 bytes of zero in the .data section is a waste of memory. It would be better for the static array to be in .bss, and then get zero initialized by the startup code.