38 lines
1.2 KiB
Factor
38 lines
1.2 KiB
Factor
! Copyright (C) 2009 Slava Pestov.
|
|
! See http://factorcode.org/license.txt for BSD license.
|
|
USING: accessors combinators.short-circuit kernel sequences math
|
|
compiler.utilities compiler.cfg compiler.cfg.instructions compiler.cfg.rpo
|
|
compiler.cfg.predecessors compiler.cfg.utilities ;
|
|
IN: compiler.cfg.block-joining
|
|
|
|
! Joining blocks that are not calls and are connected by a single CFG edge.
|
|
! This pass does not update ##phi nodes and should therefore only run
|
|
! before stack analysis.
|
|
: join-block? ( bb -- ? )
|
|
{
|
|
[ kill-block? not ]
|
|
[ predecessors>> length 1 = ]
|
|
[ predecessor kill-block? not ]
|
|
[ predecessor successors>> length 1 = ]
|
|
[ [ predecessor ] keep back-edge? not ]
|
|
} 1&& ;
|
|
|
|
: join-instructions ( bb pred -- )
|
|
[ instructions>> ] bi@ dup pop* push-all ;
|
|
|
|
: update-successors ( bb pred -- )
|
|
[ successors>> ] dip (>>successors) ;
|
|
|
|
: join-block ( bb pred -- )
|
|
[ join-instructions ] [ update-successors ] 2bi ;
|
|
|
|
: join-blocks ( cfg -- cfg' )
|
|
needs-predecessors
|
|
|
|
dup post-order [
|
|
dup join-block?
|
|
[ dup predecessor join-block ] [ drop ] if
|
|
] each
|
|
|
|
cfg-changed predecessors-changed ;
|