factor/basis/compiler/cfg/ssa/construction/tdmsc/tdmsc.factor

98 lines
2.5 KiB
Factor

! Copyright (C) 2009 Slava Pestov.
! See http://factorcode.org/license.txt for BSD license.
USING: accessors arrays assocs bit-arrays bit-sets fry
hashtables hints kernel locals math namespaces sequences sets
compiler.cfg compiler.cfg.dominance compiler.cfg.rpo ;
FROM: namespaces => set ;
IN: compiler.cfg.ssa.construction.tdmsc
! TDMSC-I algorithm from "A Practical and Fast Iterative Algorithm for
! Phi-Function Computation Using DJ Graphs"
! http://portal.acm.org/citation.cfm?id=1065887.1065890
<PRIVATE
SYMBOLS: visited merge-sets levels again? ;
: init-merge-sets ( cfg -- )
post-order dup length '[ _ <bit-set> ] H{ } map>assoc merge-sets set ;
: compute-levels ( cfg -- )
0 over entry>> associate [
'[
_ [ [ dom-parent ] dip at 1 + ] 2keep set-at
] each-basic-block
] keep levels set ;
: j-edge? ( from to -- ? )
2dup eq? [ 2drop f ] [ dominates? not ] if ;
: level ( bb -- n ) levels get at ; inline
: update-merge-set ( tmp to -- )
[ merge-sets get ] dip
'[
_
[ merge-sets get at union ]
[ number>> over adjoin ]
bi
] change-at ;
:: walk ( tmp to lnode -- lnode )
tmp level to level >= [
tmp to update-merge-set
tmp dom-parent to tmp walk
] [ lnode ] if ;
: each-incoming-j-edge ( ... bb quot: ( ... from to -- ... ) -- ... )
[ [ predecessors>> ] keep ] dip
'[ _ 2dup j-edge? _ [ 2drop ] if ] each ; inline
: visited? ( pair -- ? ) visited get in? ;
: consistent? ( snode lnode -- ? )
[ merge-sets get at ] bi@ subset? ;
: (process-edge) ( from to -- )
f walk [
2dup 2array visited? [
consistent? [ again? on ] unless
] [ 2drop ] if
] each-incoming-j-edge ;
: process-edge ( from to -- )
2dup 2array dup visited? [ 3drop ] [
visited get adjoin
(process-edge)
] if ;
: process-block ( bb -- )
[ process-edge ] each-incoming-j-edge ;
: compute-merge-set-step ( bfo -- )
HS{ } clone visited set
[ process-block ] each ;
: compute-merge-set-loop ( cfg -- )
breadth-first-order
'[ again? off _ compute-merge-set-step again? get ]
loop ;
: (merge-set) ( bbs -- flags rpo )
merge-sets get '[ _ at ] [ union ] map-reduce
cfg get reverse-post-order ; inline
PRIVATE>
: compute-merge-sets ( cfg -- )
needs-dominance
[ compute-levels ]
[ init-merge-sets ]
[ compute-merge-set-loop ]
tri ;
: merge-set ( bbs -- bbs' )
(merge-set) [ members ] dip nths ;