@begin: scope:[]  from
  [0] phi()
  to:@1
@1: scope:[]  from @begin
  [1] phi()
  [2] call main 
  to:@end
@end: scope:[]  from @1
  [3] phi()

(void()) main()
main: scope:[main]  from @1
  [4] (volatile byte) main::i ← (byte) 3
  to:main::@1
main::@1: scope:[main]  from main main::@2
  [5] if((volatile byte) main::i<(byte) 7) goto main::@2
  to:main::@return
main::@return: scope:[main]  from main::@1
  [6] return 
  to:@return
main::@2: scope:[main]  from main::@1
  [7] *((const nomodify byte*) SCREEN + (volatile byte) main::i) ← (volatile byte) main::i
  [8] (volatile byte) main::i ← ++ (volatile byte) main::i
  to:main::@1