compute-next-uses ( cfg -- entries exits )

Vocabulary

compiler.cfg.register-allocation.chordal.spilling.next-use

Inputs

cfg

an object

Outputs

entries	an object
exits	an object

Definition

USING: assocs compiler.cfg.loop-detection compiler.cfg.rpo
kernel sequences ;

IN: compiler.cfg.register-allocation.chordal.spilling.next-use

:: compute-next-uses ( cfg -- entries exits )
    cfg needs-loops cfg reverse-post-order :> blocks blocks
    [ H{ } clone ] H{ } map>assoc :> entries blocks
    [ H{ } clone ] H{ } map>assoc :> exits t :> changed!
    [ changed ] [
        f changed! blocks <reversed> [| bb |
            bb entries successor-next-use
            :> after after bb block-next-use
            :> before before bb entries at = not
            [ t changed! ] when before bb entries set-at
            after bb exits set-at
        ] each
    ] while entries exits ;