join-block? ( bb -- ? )

Vocabulary

compiler.cfg.block-joining

Inputs

bb	a basic-block

Outputs

?

a boolean

Word description

Whether the block can be joined with its predecessor or not. Two blocks can only be joined if:

•	Neither of them are kill blocks
•	They have only one predecessor and it has only one successor
•	The predecessor has a lower block number

Definition

USING: accessors combinators.short-circuit
compiler.cfg.utilities kernel sequences ;

IN: compiler.cfg.block-joining

: join-block? ( bb -- ? )
    {
        [ kill-block?>> not ]
        [ predecessors>> length 1 = ]
        [ predecessor kill-block?>> not ]
        [ predecessor successors>> length 1 = ]
        [ [ predecessor ] keep back-edge? not ]
    } 1&& ;