
void main()
main: scope:[main]  from
  [0] phi()
  to:main::@1
main::@1: scope:[main]  from main main::@3
  [1] main::vacant#3 = phi( main/1, main::@3/main::vacant#2 )
  [1] main::pos#2 = phi( main/1, main::@3/main::pos#1 )
  [2] main::pos#1 = main::pos#2 + main::move
  [3] if(0==main::pos#1) goto main::@4
  to:main::@2
main::@4: scope:[main]  from main::@1
  [4] phi()
  to:main::@2
main::@2: scope:[main]  from main::@1 main::@4
  [5] main::vacant#2 = phi( main::@4/main::vacant#3, main::@1/0 )
  [6] if(0==main::pos#1) goto main::@return
  to:main::@3
main::@3: scope:[main]  from main::@2
  [7] if(0!=main::vacant#2) goto main::@1
  to:main::@return
main::@return: scope:[main]  from main::@2 main::@3
  [8] return 
  to:@return
