reuse the same words vector on every block, x1.5 speedup
reuse the same words vector on every block, x1.5 speedup

svn: r2914

mafagafogigante/racket,mafagafogigante/racket,mafagafogigante/racket,mafagafogigante/racket,mafagafogigante/racket,mafagafogigante/racket,mafagafogigante/racket,mafagafogigante/racket,mafagafogigante/racket