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.registers
11 compiler.cfg.dominance
12 compiler.cfg.instructions
13 compiler.cfg.liveness.ssa
15 compiler.cfg.ssa.interference
16 compiler.cfg.ssa.interference.live-ranges
17 compiler.cfg.utilities
19 IN: compiler.cfg.ssa.destruction
21 ! Maps vregs to leaders.
24 : leader ( vreg -- vreg' ) leader-map get compress-path ;
26 ! Maps leaders to equivalence class elements.
27 SYMBOL: class-element-map
29 : class-elements ( vreg -- elts ) class-element-map get at ;
31 ! Sequence of vreg pairs
34 : init-coalescing ( -- )
35 H{ } clone leader-map set
36 H{ } clone class-element-map set
37 V{ } clone copies set ;
39 : classes-interfere? ( vreg1 vreg2 -- ? )
40 [ leader ] bi@ 2dup eq? [ 2drop f ] [
41 [ class-elements flatten ] bi@ sets-interfere?
44 : update-leaders ( vreg1 vreg2 -- )
45 swap leader-map get set-at ;
47 : merge-classes ( vreg1 vreg2 -- )
48 [ [ class-elements ] bi@ push ]
49 [ drop class-element-map get delete-at ] 2bi ;
51 : eliminate-copy ( vreg1 vreg2 -- )
59 : introduce-vreg ( vreg -- )
60 [ leader-map get conjoin ]
61 [ [ 1vector ] keep class-element-map get set-at ] bi ;
63 GENERIC: prepare-insn ( insn -- )
65 : try-to-coalesce ( dst src -- ) 2array copies get push ;
68 [ defs-vreg ] [ uses-vregs ] bi
71 2dup [ rep-of reg-class-of ] bi@ eq?
72 [ try-to-coalesce ] [ 2drop ] if
75 M: ##copy prepare-insn
76 [ dst>> ] [ src>> ] bi try-to-coalesce ;
79 [ dst>> ] [ inputs>> values ] bi
80 [ eliminate-copy ] with each ;
82 : prepare-block ( bb -- )
83 instructions>> [ prepare-insn ] each ;
85 : prepare-coalescing ( cfg -- )
87 defs get keys [ introduce-vreg ] each
88 [ prepare-block ] each-basic-block ;
90 : process-copies ( -- )
92 2dup classes-interfere?
93 [ 2drop ] [ eliminate-copy ] if
96 : useless-copy? ( ##copy -- ? )
97 dup ##copy? [ [ dst>> ] [ src>> ] bi eq? ] [ drop f ] if ;
99 : perform-renaming ( cfg -- )
100 leader-map get keys [ dup leader ] H{ } map>assoc renamings set
105 [ [ useless-copy? ] [ ##phi? ] bi or not ] tri
109 : destruct-ssa ( cfg -- cfg' )
114 compute-ssa-live-sets
115 dup compute-live-ranges
116 dup prepare-coalescing
118 dup perform-renaming ;