1 ! Copyright (C) 2009, 2010 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 FROM: namespaces => set ;
19 IN: compiler.cfg.ssa.destruction
21 ! Maps vregs to leaders.
24 : leader ( vreg -- vreg' ) leader-map get compress-path ;
26 ! Maps basic blocks to ##phi instruction outputs
29 : phi-set ( bb -- vregs ) phi-sets get at ;
31 ! Maps leaders to equivalence class elements.
32 SYMBOL: class-element-map
34 : class-elements ( vreg -- elts ) class-element-map get at ;
36 ! Sequence of vreg pairs
39 : init-coalescing ( -- )
40 H{ } clone leader-map set
41 H{ } clone class-element-map set
42 V{ } clone copies set ;
44 : classes-interfere? ( vreg1 vreg2 -- ? )
45 [ leader ] bi@ 2dup eq? [ 2drop f ] [
46 [ class-elements flatten ] bi@ sets-interfere?
49 : update-leaders ( vreg1 vreg2 -- )
50 swap leader-map get set-at ;
52 : merge-classes ( vreg1 vreg2 -- )
53 [ [ class-elements ] bi@ push ]
54 [ drop class-element-map get delete-at ] 2bi ;
56 : eliminate-copy ( vreg1 vreg2 -- )
64 : introduce-vreg ( vreg -- )
65 [ leader-map get conjoin ]
66 [ [ 1vector ] keep class-element-map get set-at ] bi ;
68 GENERIC: prepare-insn ( insn -- )
70 : try-to-coalesce ( dst src -- ) 2array copies get push ;
73 [ defs-vreg ] [ uses-vregs ] bi
76 2dup [ rep-of ] bi@ eq?
77 [ try-to-coalesce ] [ 2drop ] if
80 M: ##copy prepare-insn
81 [ dst>> ] [ src>> ] bi try-to-coalesce ;
84 [ dst>> ] [ inputs>> values ] bi
85 [ eliminate-copy ] with each ;
87 : prepare-block ( bb -- )
88 instructions>> [ prepare-insn ] each ;
90 : prepare-coalescing ( cfg -- )
92 defs get keys [ introduce-vreg ] each
93 [ prepare-block ] each-basic-block ;
95 : process-copies ( -- )
97 2dup classes-interfere?
98 [ 2drop ] [ eliminate-copy ] if
101 GENERIC: rename-insn ( insn -- keep? )
103 M: vreg-insn rename-insn
104 [ rename-insn-defs ] [ rename-insn-uses ] bi t ;
106 M: ##copy rename-insn
107 [ call-next-method drop ]
108 [ [ dst>> ] [ src>> ] bi eq? not ] bi ;
110 SYMBOL: current-phi-set
112 M: ##phi rename-insn dst>> current-phi-set get push f ;
114 M: ##call-gc rename-insn
115 [ renamings get '[ _ at ] map members ] change-gc-roots drop t ;
117 M: insn rename-insn drop t ;
119 : renaming-in-block ( bb -- )
120 V{ } clone current-phi-set set
121 [ [ current-phi-set ] dip phi-sets get set-at ]
122 [ instructions>> [ rename-insn ] filter! drop ]
125 : perform-renaming ( cfg -- )
126 H{ } clone phi-sets set
127 leader-map get keys [ dup leader ] H{ } map>assoc renamings set
128 [ renaming-in-block ] each-basic-block ;
130 : destruct-ssa ( cfg -- cfg' )
135 dup compute-ssa-live-sets
136 dup compute-live-ranges
137 dup prepare-coalescing
139 dup perform-renaming ;