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.instructions
11 compiler.cfg.liveness.ssa
13 compiler.cfg.ssa.interference
14 compiler.cfg.ssa.interference.live-ranges
15 compiler.cfg.utilities
17 IN: compiler.cfg.ssa.destruction
19 ! Maps vregs to leaders.
22 : leader ( vreg -- vreg' ) leader-map get compress-path ;
24 ! Maps leaders to equivalence class elements.
25 SYMBOL: class-element-map
27 : class-elements ( vreg -- elts ) class-element-map get at ;
29 ! Sequence of vreg pairs
32 : init-coalescing ( -- )
33 H{ } clone leader-map set
34 H{ } clone class-element-map set
35 V{ } clone copies set ;
37 : classes-interfere? ( vreg1 vreg2 -- ? )
38 [ leader ] bi@ 2dup eq? [ 2drop f ] [
39 [ class-elements flatten ] bi@ sets-interfere?
42 : update-leaders ( vreg1 vreg2 -- )
43 swap leader-map get set-at ;
45 : merge-classes ( vreg1 vreg2 -- )
46 [ [ class-elements ] bi@ push ]
47 [ drop class-element-map get delete-at ] 2bi ;
49 : eliminate-copy ( vreg1 vreg2 -- )
57 : introduce-vreg ( vreg -- )
58 [ leader-map get conjoin ]
59 [ [ 1vector ] keep class-element-map get set-at ] bi ;
61 GENERIC: prepare-insn ( insn -- )
63 M: ##copy prepare-insn
64 [ dst>> ] [ src>> ] bi 2array copies get push ;
67 [ dst>> ] [ inputs>> values ] bi
68 [ eliminate-copy ] with each ;
70 M: insn prepare-insn drop ;
72 : prepare-block ( bb -- )
73 instructions>> [ prepare-insn ] each ;
75 : prepare-coalescing ( cfg -- )
77 defs get keys [ introduce-vreg ] each
78 [ prepare-block ] each-basic-block ;
80 : process-copies ( -- )
82 2dup classes-interfere?
83 [ 2drop ] [ eliminate-copy ] if
86 : useless-copy? ( ##copy -- ? )
87 dup ##copy? [ [ dst>> ] [ src>> ] bi eq? ] [ drop f ] if ;
89 : perform-renaming ( cfg -- )
90 leader-map get keys [ dup leader ] H{ } map>assoc renamings set
95 [ [ useless-copy? ] [ ##phi? ] bi or not ] tri
99 : destruct-ssa ( cfg -- cfg' )
104 compute-ssa-live-sets
105 dup compute-live-ranges
106 dup prepare-coalescing
108 dup perform-renaming ;