
void main()
main: scope:[main]  from
  [0] phi()
  to:main::@1
main::@1: scope:[main]  from main main::@2
  [1] main::key#0 = *RASTER
  [2] if(main::key#0>=$20+1) goto main::@2
  to:main::@3
main::@3: scope:[main]  from main::@1
  [3] if(main::key#0>=$40) goto main::@4
  to:main::@2
main::@4: scope:[main]  from main::@3
  [4] phi()
  to:main::@2
main::@2: scope:[main]  from main::@1 main::@3 main::@4
  [5] main::key#2 = phi( main::@4/main::key#0, main::@1/0, main::@3/0 )
  [6] *SCREEN = main::key#2
  to:main::@1
