1 ! Copyright (C) 2008, 2010 Slava Pestov, 2011 Alex Vondrak
2 ! See http://factorcode.org/license.txt for BSD license.
3 USING: namespaces arrays assocs hashtables kernel accessors fry
4 grouping sorting sets sequences locals
10 compiler.cfg.utilities
11 compiler.cfg.instructions
12 compiler.cfg.predecessors
13 compiler.cfg.gvn.alien
14 compiler.cfg.gvn.avail
15 compiler.cfg.gvn.comparisons
16 compiler.cfg.gvn.graph
18 compiler.cfg.gvn.rewrite
19 compiler.cfg.gvn.slots
21 compiler.cfg.gvn.expressions ;
24 GENERIC: simplify ( insn -- insn' )
26 M: insn simplify dup rewrite [ simplify ] [ dup >avail-insn-uses ] ?if ;
27 M: array simplify [ simplify ] map ;
30 ! ! ! Global value numbering
32 GENERIC: value-number ( insn -- )
34 M: array value-number [ value-number ] each ;
36 : record-defs ( insn -- ) defs-vregs [ dup set-vn ] each ;
38 M: alien-call-insn value-number record-defs ;
39 M: ##callback-inputs value-number record-defs ;
41 M: ##copy value-number [ src>> vreg>vn ] [ dst>> ] bi set-vn ;
43 : redundant-instruction ( insn vn -- )
46 :: useful-instruction ( insn expr -- )
49 vn expr exprs>vns get set-at
50 insn vn vns>insns get set-at ;
52 : check-redundancy ( insn -- )
53 dup >expr dup exprs>vns get at
54 [ redundant-instruction ] [ useful-instruction ] ?if ;
57 dup inputs>> values [ vreg>vn ] map sift
59 [ drop ] [ first redundant-instruction ] if-empty
60 ] [ drop check-redundancy ] if ;
63 dup defs-vregs length 1 = [ check-redundancy ] [ drop ] if ;
65 : value-numbering-step ( insns -- )
66 [ simplify value-number ] each ;
68 : value-numbering-iteration ( cfg -- )
69 clear-exprs [ value-numbering-step ] simple-analysis ;
71 : determine-value-numbers ( cfg -- )
76 _ value-numbering-iteration
80 ! ! ! Global common subexpression elimination
82 GENERIC: gcse ( insn -- insn' )
84 M: array gcse [ gcse ] map ;
86 : defs-available ( insn -- insn )
87 dup defs-vregs [ make-available ] each ;
89 M: alien-call-insn gcse defs-available ;
90 M: ##callback-inputs gcse defs-available ;
91 M: ##copy gcse defs-available ;
93 : ?eliminate ( insn vn -- insn' )
95 [ dst>> dup make-available ] dip <copy>
96 ] [ drop defs-available ] if ;
98 : eliminate-redundancy ( insn -- insn' )
99 dup >expr exprs>vns get at >avail-vreg
100 [ ?eliminate ] [ defs-available ] if* ;
103 dup inputs>> values [ vreg>vn ] map sift
105 [ first ?eliminate ] unless-empty
106 ] [ drop eliminate-redundancy ] if ;
109 dup defs-vregs length 1 = [ eliminate-redundancy ] when ;
111 : gcse-step ( insns -- insns' )
112 [ simplify gcse ] map flatten ;
114 : eliminate-common-subexpressions ( cfg -- )
116 compute-congruence-classes
117 dup compute-avail-sets
118 [ gcse-step ] simple-optimization ;
120 : value-numbering ( cfg -- cfg )
122 dup determine-value-numbers
123 dup eliminate-common-subexpressions
125 cfg-changed predecessors-changed ;