% -*- mode: latex -*-

  \begin{tikzpicture}[->,>=stealth',shorten >=1pt,auto,node distance=2.8cm,
    semithick,font={\footnotesize}]
   
    \tikzstyle{basic-state} = [draw, fill=white, circle, minimum width=5em, node
                         distance=10em]

    \ifthenelse{\boolean{preview}}
      {\tikzstyle{state} = [basic-state]}
      {\tikzstyle{state} = [basic-state, drop shadow]}

    \tikzstyle{lbl} = [font={\scriptsize\it}]

    \node[state, name=interp] {Interpretation};
    \node[state, name=tracing, above right of=interp] {Tracing};
    \node[state, name=compile, right of=tracing] {Compilation};
    \node[state, name=running, below right of=compile] {Running};
    
    \path
        (interp)    edge[bend left]        node[lbl] {hot loop detected}        (tracing)
        (running)   edge[<-,bend left=20]  node[lbl] {entering compiled loop}   (interp)
        (tracing)   edge[bend left]                                             (compile)
        (compile)   edge[bend left]                                             (running)
        (running)   edge[bend left=50]     node[lbl] {cold guard failed}        (interp)
        (running)   edge[bend left=15]     node[lbl] {guard failure $\rightarrow$ hot}  (tracing)
        (running)   edge[loop below]       node[lbl] {hot guard failed}         (running)
        ;
  \end{tikzpicture}