fuse-multiply-negate ( cfg -- )

Vocabulary

compiler.cfg.multiply-negate

Inputs

cfg

an object

Outputs

None

Definition

USING: accessors assocs compiler.cfg compiler.cfg.def-use
compiler.cfg.instructions compiler.cfg.rpo kernel sequences ;

IN: compiler.cfg.multiply-negate

:: fuse-multiply-negate ( cfg -- )
    cfg post-order :> blocks blocks
    [ instructions>> [ ##neg? ] any? ] any? [
        H{ } clone :> definitions
        H{ } clone :> use-counts blocks [
            instructions>> [| insn |
                insn defs-vregs
                [ insn swap definitions set-at ] each
                insn uses-vregs [ use-counts inc-at ] each
            ] each
        ] each cfg
        [ [ definitions use-counts fuse-negated-product ] map ]
        simple-optimization cfg cfg-changed
    ] when ;