12. a) Convert the following C code to Arm:

unsigned long long sum( unsigned long long arr[], unsigned long long size ) {if ( size == 0 )

return 0 ;else

return sum( arr, size - 1 ) + arr[ size - 1 ] ; }

Assume arr is in x19 and size is in x20 and follow all standard ARM conventions for procedures. Also, assume that the unsigned long long data type corresponds to a 64-bit unsigned integer.

b) What else would be saved on the stack?