1 ! Copyright (C) 2009 Slava Pestov.
2 ! See http://factorcode.org/license.txt for BSD license.
3 USING: accessors arrays assocs bit-arrays bit-sets fry
4 hashtables hints kernel locals math namespaces sequences sets
5 compiler.cfg compiler.cfg.dominance compiler.cfg.rpo ;
6 FROM: namespaces => set ;
7 IN: compiler.cfg.ssa.construction.tdmsc
9 ! TDMSC-I algorithm from "A Practical and Fast Iterative Algorithm for
10 ! Phi-Function Computation Using DJ Graphs"
12 ! http://portal.acm.org/citation.cfm?id=1065887.1065890
16 SYMBOLS: visited merge-sets levels again? ;
18 : init-merge-sets ( cfg -- )
19 post-order dup length '[ _ <bit-set> ] H{ } map>assoc merge-sets set ;
21 : compute-levels ( cfg -- )
22 0 over entry>> associate [
24 _ [ [ dom-parent ] dip at 1 + ] 2keep set-at
28 : j-edge? ( from to -- ? )
29 2dup eq? [ 2drop f ] [ dominates? not ] if ;
31 : level ( bb -- n ) levels get at ; inline
33 : update-merge-set ( tmp to -- )
34 [ merge-sets get ] dip
37 [ merge-sets get at union ]
38 [ number>> over adjoin ]
42 :: walk ( tmp to lnode -- lnode )
43 tmp level to level >= [
44 tmp to update-merge-set
45 tmp dom-parent to tmp walk
48 : each-incoming-j-edge ( ... bb quot: ( ... from to -- ... ) -- ... )
49 [ [ predecessors>> ] keep ] dip
50 '[ _ 2dup j-edge? _ [ 2drop ] if ] each ; inline
52 : visited? ( pair -- ? ) visited get in? ;
54 : consistent? ( snode lnode -- ? )
55 [ merge-sets get at ] bi@ subset? ;
57 : (process-edge) ( from to -- )
59 2dup 2array visited? [
60 consistent? [ again? on ] unless
62 ] each-incoming-j-edge ;
64 : process-edge ( from to -- )
65 2dup 2array dup visited? [ 3drop ] [
70 : process-block ( bb -- )
71 [ process-edge ] each-incoming-j-edge ;
73 : compute-merge-set-step ( bfo -- )
74 HS{ } clone visited set
75 [ process-block ] each ;
77 : compute-merge-set-loop ( cfg -- )
79 '[ again? off _ compute-merge-set-step again? get ]
82 : (merge-set) ( bbs -- flags rpo )
83 merge-sets get '[ _ at ] [ union ] map-reduce
84 cfg get reverse-post-order ; inline
88 : compute-merge-sets ( cfg -- )
91 HS{ } clone visited set
94 [ compute-merge-set-loop ]
97 : merge-set ( bbs -- bbs' )
98 (merge-set) [ members ] dip nths ;
100 : merge-set-each ( bbs quot: ( bb -- ) -- )
101 [ merge-set ] dip each ; inline