== main ==
fun main() {
    while(1 > 0) {
      2
    }
}
---------------------
l0:
    <START>        NEXT:[r(1)]                 PREV:[]
l2:
l5:
    r(1)           NEXT:[r(0)]                 PREV:[<START>, jmp(l2)]
    r(0)           NEXT:[r(>)]                 PREV:[r(1)]
    r(>)           NEXT:[r(1 > 0)]             PREV:[r(0)]
    r(1 > 0)       NEXT:[jf(l3)]               PREV:[r(>)]
    jf(l3)         NEXT:[read (Unit), r(2)]    PREV:[r(1 > 0)]
l4:
    r(2)           NEXT:[jmp(l2)]              PREV:[jf(l3)]
    jmp(l2)        NEXT:[r(1)]                 PREV:[r(2)]
l3:
    read (Unit)    NEXT:[<END>]                PREV:[jf(l3)]
l1:
    <END>          NEXT:[<SINK>]               PREV:[read (Unit)]
error:
    <ERROR>        NEXT:[]                     PREV:[]
sink:
    <SINK>         NEXT:[]                     PREV:[<END>]
=====================
== dowhile ==
fun dowhile() {
    do {return}
    while(1 > 0)
}
---------------------
l0:
    <START>        NEXT:[ret l1]                 PREV:[]
l2:
l4:
    ret l1         NEXT:[<END>]                  PREV:[<START>]
l5:
*   r(1)           NEXT:[r(0)]                   PREV:[]
*   r(0)           NEXT:[r(>)]                   PREV:[]
*   r(>)           NEXT:[r(1 > 0)]               PREV:[]
*   r(1 > 0)       NEXT:[jt(l2)]                 PREV:[]
*   jt(l2)         NEXT:[read (Unit), ret l1]    PREV:[]
l3:
*   read (Unit)    NEXT:[<END>]                  PREV:[]
l1:
    <END>          NEXT:[<SINK>]                 PREV:[ret l1]
error:
    <ERROR>        NEXT:[]                       PREV:[]
sink:
    <SINK>         NEXT:[]                       PREV:[<END>]
=====================