1 ! Copyright (C) 2009 Slava Pestov.
2 ! See http://factorcode.org/license.txt for BSD license.
3 USING: accessors arrays assocs fry kernel namespaces
4 sequences sequences.deep
10 compiler.cfg.dominance
11 compiler.cfg.instructions
12 compiler.cfg.liveness.ssa
14 compiler.cfg.ssa.interference
15 compiler.cfg.ssa.interference.live-ranges
16 compiler.cfg.utilities
18 IN: compiler.cfg.ssa.destruction
20 ! Maps vregs to leaders.
23 : leader ( vreg -- vreg' ) leader-map get compress-path ;
25 ! Maps leaders to equivalence class elements.
26 SYMBOL: class-element-map
28 : class-elements ( vreg -- elts ) class-element-map get at ;
30 ! Sequence of vreg pairs
33 : init-coalescing ( -- )
34 H{ } clone leader-map set
35 H{ } clone class-element-map set
36 V{ } clone copies set ;
38 : classes-interfere? ( vreg1 vreg2 -- ? )
39 [ leader ] bi@ 2dup eq? [ 2drop f ] [
40 [ class-elements flatten ] bi@ sets-interfere?
43 : update-leaders ( vreg1 vreg2 -- )
44 swap leader-map get set-at ;
46 : merge-classes ( vreg1 vreg2 -- )
47 [ [ class-elements ] bi@ push ]
48 [ drop class-element-map get delete-at ] 2bi ;
50 : eliminate-copy ( vreg1 vreg2 -- )
58 : introduce-vreg ( vreg -- )
59 [ leader-map get conjoin ]
60 [ [ 1vector ] keep class-element-map get set-at ] bi ;
62 GENERIC: prepare-insn ( insn -- )
64 : try-to-coalesce ( dst src -- ) 2array copies get push ;
67 [ defs-vreg ] [ uses-vregs ] bi
70 2dup [ rep-of ] bi@ eq?
71 [ try-to-coalesce ] [ 2drop ] if
74 M: ##copy prepare-insn
75 [ dst>> ] [ src>> ] bi try-to-coalesce ;
78 [ dst>> ] [ inputs>> values ] bi
79 [ eliminate-copy ] with each ;
81 : prepare-block ( bb -- )
82 instructions>> [ prepare-insn ] each ;
84 : prepare-coalescing ( cfg -- )
86 defs get keys [ introduce-vreg ] each
87 [ prepare-block ] each-basic-block ;
89 : process-copies ( -- )
91 2dup classes-interfere?
92 [ 2drop ] [ eliminate-copy ] if
95 : useless-copy? ( ##copy -- ? )
96 dup ##copy? [ [ dst>> ] [ src>> ] bi eq? ] [ drop f ] if ;
98 : perform-renaming ( cfg -- )
99 leader-map get keys [ dup leader ] H{ } map>assoc renamings set
104 [ [ useless-copy? ] [ ##phi? ] bi or not ] tri
108 : destruct-ssa ( cfg -- cfg' )
113 compute-ssa-live-sets
114 dup compute-live-ranges
115 dup prepare-coalescing
117 dup perform-renaming ;