factor/basis/compiler/cfg/dominance/dominance.factor

101 lines
2.4 KiB
Factor

! Copyright (C) 2009 Slava Pestov.
! See http://factorcode.org/license.txt for BSD license.
USING: accessors assocs combinators compiler.cfg.predecessors
compiler.cfg.rpo deques dlists fry kernel locals math math.order
namespaces sequences sorting vectors ;
IN: compiler.cfg.dominance
<PRIVATE
SYMBOL: dom-parents
PRIVATE>
: dom-parent ( bb -- bb' ) dom-parents get at ;
<PRIVATE
: set-idom ( idom bb -- changed? )
dom-parents get maybe-set-at ;
: intersect ( finger1 finger2 -- bb )
2dup [ number>> ] compare {
{ +gt+ [ [ dom-parent ] dip intersect ] }
{ +lt+ [ dom-parent intersect ] }
[ 2drop ]
} case ;
: compute-idom ( bb -- idom )
predecessors>> [ dom-parent ] filter
[ ] [ intersect ] map-reduce ;
: iterate ( rpo -- changed? )
f [ [ compute-idom ] keep set-idom or ] reduce ;
: compute-dom-parents ( cfg -- )
H{ } clone dom-parents set
reverse-post-order
unclip dup set-idom drop '[ _ iterate ] loop ;
SYMBOL: dom-childrens
PRIVATE>
: dom-children ( bb -- seq ) dom-childrens get at ;
<PRIVATE
: compute-dom-children ( dom-parents -- dom-childrens )
H{ } clone [ '[ 2dup eq? [ 2drop ] [ _ push-at ] if ] assoc-each ] keep
[ [ number>> ] sort-with ] assoc-map ;
SYMBOLS: preorder maxpreorder ;
PRIVATE>
: pre-of ( bb -- n ) [ preorder get at ] [ -1/0. ] if* ;
: maxpre-of ( bb -- n ) [ maxpreorder get at ] [ 1/0. ] if* ;
<PRIVATE
: (compute-dfs) ( n bb -- n )
[ 1 + ] dip
[ dupd preorder get set-at ]
[ dom-children [ (compute-dfs) ] each ]
[ dupd maxpreorder get set-at ]
tri ;
: compute-dfs ( cfg -- )
H{ } clone preorder set
H{ } clone maxpreorder set
[ 0 ] dip entry>> (compute-dfs) drop ;
: compute-dominance ( cfg -- )
[
compute-dom-parents
dom-parents get compute-dom-children dom-childrens set
] [ compute-dfs ] bi ;
PRIVATE>
: needs-dominance ( cfg -- )
[ needs-predecessors ]
[
dup dominance-valid?>> [ drop ]
[ t >>dominance-valid? compute-dominance ] if
] bi ;
: dominates? ( bb1 bb2 -- ? )
swap [ pre-of ] [ [ pre-of ] [ maxpre-of ] bi ] bi* between? ;
:: breadth-first-order ( cfg -- bfo )
<dlist> :> work-list
cfg post-order length <vector> :> accum
cfg entry>> work-list push-front
work-list [
[ accum push ]
[ dom-children work-list push-all-front ] bi
] slurp-deque
accum ;