@begin: scope:[]  from
  [0] phi()
  to:@2
@2: scope:[]  from @begin
  [1] phi()
  [2] call main 
  to:@end
@end: scope:[]  from @2
  [3] phi()
main: scope:[main]  from @2
  [4] *((const byte*) main::screen#0) ← (byte/signed byte/word/signed word/dword/signed dword) 1
  to:main::@return
main::@return: scope:[main]  from main
  [5] return 
  to:@return
