@begin: scope:[]  from
  [0] phi()
  to:@1
@1: scope:[]  from @begin
  [1] phi()
  [2] call main 
  to:@end
@end: scope:[]  from @1
  [3] phi()
main: scope:[main]  from @1
  [4] phi()
  to:main::@1
main::@1: scope:[main]  from main
  [5] *((const byte*) main::SCREEN#0) ← (byte) 'a'
  to:main::@2
main::@2: scope:[main]  from main::@1
  [6] *((const byte*) main::SCREEN#0+(byte) 1) ← (byte) 'b'
  to:main::@return
main::@return: scope:[main]  from main::@2
  [7] return 
  to:@return