void main()
main: scope:[main]  from
  [0] phi()
  to:main::@1
main::@1: scope:[main]  from main main::@2
  [1] main::i#2 = phi( main/7, main::@2/main::i#5 )
  [2] main::i#1 = ++ main::i#2
  [3] if(main::i#2!=7) goto main::@2
  to:main::@3
main::@3: scope:[main]  from main::@1
  [4] SCREEN[main::i#1] = 'x'
  to:main::@return
main::@return: scope:[main]  from main::@3
  [5] return 
  to:@return
main::@2: scope:[main]  from main::@1
  [6] SCREEN[main::i#1] = main::i#1
  [7] main::i#5 = main::i#1
  to:main::@1