question: private void computeClosure ( ) { for ( Enumeration < GraphNode > e = enumerateVertices ( ) ; e . hasMoreElements ( ) ; ) { ValueGraphVertex v = ( ValueGraphVertex ) e . nextElement ( ) ; if ( v . getName ( ) instanceof Register ) { if ( v . getLabel ( ) instanceof Register ) { if ( v . getName ( ) != v . getLabel ( ) ) { ValueGraphVertex v2 = getVertex ( v . getLabel ( ) ) ; if ( VM . VerifyAssertions ) { if ( v2 . getName ( ) instanceof Register && v2 . getLabel ( ) instanceof Register && v2 . getLabel ( ) != v2 . getName ( ) ) { VM . _assert ( VM . NOT_REACHED ) ; } } v . copyVertex ( v2 ) ; } } } } }
target:  Due to PI nodes and Moves, the initial label for a register may be another register.  Fix up the value graph for cases where the initial register label was not removed.